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24 THE BLOOD 32 JOURNEY TO THE 38 HERE COME THE 06 NEWS IS HERE CENTER OF THE HEARABLES 15 RESOURCES The world’s first SOLAR SYSTEM Devices tucked inside 20 OPINION THE commercial drone Here’s how the your ears will make delivery service is Parker Solar Probe technology more On the cover flying medical supplies can take the heat. personal than ever. Illustration for MARVELOUS through Rwanda’s By Andrew Driesman, By Poppy Crum IEEE Spectrum skies. Jack Ercol, by Tavis Coburn By Evan Ackerman & Edward Gaddy MR. MEMS Michael Koziol & Andrew Gerger Kurt Petersen, recipient of the 2019 IEEE Medal of Honor, helped launch the MEMS industry. Page 44 by tekla s. perry

IEEE SPECTRUM (ISSN 0018-9235) is published monthly by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved. © 2019 by The Institute of Electrical and Electronics Engineers, Inc., 3 Park Avenue, New York, NY 10016-5997, U.S.A. Volume No. 56, Issue No. 5. The editorial content of IEEE Spectrum magazine does not represent official positions of the IEEE or its organizational units. Canadian Post International Publications Mail (Canadian Distribution) Sales Agreement No. 40013087. Return undeliverable Canadian addresses to: Circulation Department, IEEE Spectrum, Box 1051, Fort Erie, ON L2A 6C7. Cable address: ITRIPLEE. Fax: +1 212 419 7570. INTERNET: [email protected]. ANNUAL SUBSCRIPTIONS: IEEE Members: $21.40 included in dues. Libraries/institutions: $399. POSTMASTER: Please send address changes to IEEE Spectrum, c/o Coding Department, IEEE Service Center, 445 Hoes Lane, Box 1331, Piscataway, NJ 08855. Periodicals postage paid at New York, NY, and additional mailing offices. Canadian GST #125634188. Printed at 120 Donnelley Dr., Glasgow, KY 42141-1060, U.S.A. IEEE Spectrum circulation is audited by BPA Worldwide. IEEE Spectrum is a member of the Association of Business Information & Media Companies, the Association of Magazine Media, and Association Media & Publishing. IEEE prohibits discrimination, harassment, and bullying. For more information, visit http://www.ieee.org/web/aboutus/whatis/policies/p9-26.html.

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Variety of applications Bonds heat sensitive components FLYING INTO THE UNKNOWN Suitable in thick sections eporters used to head out into the field with nothing Up to 0.125 inch but a notebook. But when IEEE Spectrum associate editor Michael Koziol [left] and contributing editor Evan Ackerman [right] traveled to East Africa last October, they had plenty No mixing required more gear to schlep. In addition to their laptops and digital One component systems recorders, they brought two DJI drones and an assortment of 360-degree video cameras. R The trip was part of an experiment in immersive storytelling. Koziol and Ackerman journeyed through Rwanda and Tanzania to Specific grades offer optical report on pioneering companies that are using small consumer drones clarity, dimensional stability for such tasks as delivering medical supplies and surveying roads. The and biocompatibility two gathered material for several articles, including a feature story about a company called Zipline that’s delivering blood to Rwanda’s rural hospitals [see “The Blood Is Here” in this issue]. They also sent their own drones aloft bearing their cameras, capturing footage for videos that learn how can be viewed online as part of our special report on drones in Africa. to an In these 360-degree videos the viewer can rotate the point of view in a use complete circle, to see everything on all sides of the camera. LED curing adhesive The reporters had to overcome various logistical and technical challenges to get their shots. First they had to navigate the maze of regulations that govern the flying of consumer drones, rules that differ from country to country. Because the technology is so new, the rules and procedures are a work in progress. And filming with the 360-degree cameras presented novel technical issues, says Ackerman, as he and Koziol had to consider everything that the viewer might see in the shot. There were two questions they often asked themselves, Ackerman says: “How do we make the whole scene interesting? And Scan to watch how do we hide from the camera?” The technology and the travel were funded by a generous grant from the IEEE Foundation. We thank the foundation for supporting Spectrum’s mission: covering emerging technology that can change the world, and using cutting-edge technology to do so. ■ 154 Hobart St., Hackensack, NJ 07601 USA +1.201.343.8983 • mainmasterbond.com 05.19

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02 | MAY 2019 | SPECTRUM.IEEE.ORG CONTRIBUTORS_

EDITOR IN CHIEF Susan Hassler, [email protected] ADVERTISING PRODUCTION MANAGER EXECUTIVE EDITOR Glenn Zorpette, [email protected] Felicia Spagnoli, [email protected] EDITORIAL DIRECTOR, DIGITAL SENIOR ADVERTISING PRODUCTION COORDINATOR Harry Goldstein, [email protected] Nicole Evans Gyimah, [email protected] Peter Adams MANAGING EDITOR Elizabeth A. Bretz, [email protected] EDITORIAL ADVISORY BOARD, IEEE SPECTRUM Adams is a former tech entrepreneur who found SENIOR ART DIRECTOR Susan Hassler, Chair; Steve Blank, David C. Brock, Sudhir Dixit, his true calling as a photographer specializing Mark Montgomery, [email protected] Shahin Farshchi, Limor Fried, Robert Hebner, Jason K. Hui, in capturing the tech industry. For this issue, he SENIOR EDITORS Grant Jacoby, Leah Jamieson, Mary Lou Jepsen, Deepa Kundur, Stephen Cass (Resources), [email protected] photographed IEEE Medal of Honor recipient Kurt Norberto Lerendegui, Steve Mann, Allison Marsh, Sofia Olhede, Petersen [p. 44]. When Petersen showed Adams Erico Guizzo (Digital), [email protected] Jacob Østergaard, Umit Ozguner, John Rogers, Jean Kumagai, [email protected] Jonathan Rothberg, Umar Saif, Takao Someya, examples of the tiny microelectromechanical Samuel K. Moore, [email protected] Maurizio Vecchione, Yu Zheng, Kun Zhou, Edward Zyszkowski systems he’d developed, he warned, “Careful, Tekla S. Perry, [email protected] these are so small, you could inhale them.” Adams EDITORIAL ADVISORY BOARD, THE INSTITUTE Philip E. Ross, [email protected] is happy to report that “no MEMS were ingested David Schneider, [email protected] Kathy Pretz, Chair; Qusi Alqarqaz, John Baillieul, Philip Chen, Shashank Gaur, Susan Hassler, Hulya Kirkici, Cecilia Metra, during the course of the photo shoot.” DEPUTY ART DIRECTOR Brandon Palacio, [email protected] San Murugesan, Mirela Sechi Annoni Notare, Joel Trussell, PHOTOGRAPHY DIRECTOR Randi Klett, [email protected] Hon K. Tsang, Chonggang Wang ASSOCIATE ART DIRECTOR Erik Vrielink, [email protected] SENIOR ASSOCIATE EDITOR MANAGING DIRECTOR, PUBLICATIONS Eliza Strickland, [email protected] Michael B. Forster Poppy Crum NEWS MANAGER Amy Nordrum, [email protected] EDITORIAL CORRESPONDENCE Crum is chief scientist at Dolby Laboratories ASSOCIATE EDITORS IEEE Spectrum, 3 Park Ave., 17th Floor, and an adjunct professor at Stanford University. Willie D. Jones (Digital), [email protected] New York, NY 10016-5997 Michael Koziol, [email protected] She has spoken frequently for the IEEE Tech TEL: +1 212 419 7555 FAX: +1 212 419 7570 SENIOR COPY EDITOR Joseph N. Levine, [email protected] BUREAU Palo Alto, Calif.; Tekla S. Perry +1 650 752 6661 for Humanity Series at the SXSW Conference. COPY EDITOR Michele Kogon, [email protected] A neuroscientist by training, Crum is dedicated DIRECTOR, BUSINESS DEVELOPMENT, EDITORIAL RESEARCHER Alan Gardner, [email protected] to developing technology that augments human MEDIA & ADVERTISING Mark David, [email protected] ADMINISTRATIVE ASSISTANT capacity. In this issue [p. 38], she describes the Ramona L. Foster, [email protected] ADVERTISING INQUIRIES Naylor Association Solutions, benefits of upcoming hearable devices that will CONTRIBUTING EDITORS Evan Ackerman, Mark Anderson, Erik Henson +1 352 333 3443, [email protected] Robert N. Charette, Peter Fairley, Tam Harbert, Mark Harris, listen to our environments as well as our bodies, REPRINT SALES +1 212 221 9595, ext. 319 David Kushner, Robert W. Lucky, Prachi Patel, Morgen E. Peck, to know what we’re thinking and what we need. REPRINT PERMISSION / LIBRARIES Articles may be Richard Stevenson, Lawrence Ulrich, Paul Wallich photocopied for private use of patrons. A per-copy fee must EDITOR IN CHIEF, THE INSTITUTE be paid to the Copyright Clearance Center, 29 Congress Kathy Pretz, [email protected] St., Salem, MA 01970. For other copying or republication, ASSISTANT EDITOR, THE INSTITUTE contact Managing Editor, IEEE Spectrum. Andrew Driesman Joanna Goodrich, [email protected] COPYRIGHTS AND TRADEMARKS IEEE Spectrum is a Driesman, along with coauthors Jack Ercol, DIRECTOR, PERIODICALS PRODUCTION SERVICES Peter Tuohy registered trademark owned by The Institute of Electrical and Edward Gaddy, and Andrew Gerger, works at EDITORIAL & WEB PRODUCTION MANAGER Roy Carubia Electronics Engineers Inc. Responsibility for the substance the Johns Hopkins University Applied Physics SENIOR ELECTRONIC LAYOUT SPECIALIST Bonnie Nani of articles rests upon the authors, not IEEE, its organizational PRODUCT MANAGER, DIGITAL Shannan Dunlap units, or its members. Articles do not represent official Laboratory. They’re part of the team that WEB PRODUCTION COORDINATOR Jacqueline L. Parker positions of IEEE. Readers may post comments online; developed and deployed NASA’s Parker Solar MULTIMEDIA PRODUCTION SPECIALIST Michael Spector comments may be excerpted for publication. IEEE reserves Probe, the first spacecraft to venture near the sun. ADVERTISING PRODUCTION +1 732 562 6334 the right to reject any advertising. They write about the mission in this issue [p. 32]. “I grew up in the Apollo era,” says Driesman, who after studying electrical engineering “quickly gravitated to space”—figuratively speaking, that is.

IEEE BOARD OF DIRECTORS CORPORATE ACTIVITIES Donna Hourican PRESIDENT & CEO José M.F. Moura, [email protected] +1 732 562 6330, [email protected] Andrew Jones +1 732 562 3928 FAX: +1 732 465 6444 MEMBER & GEOGRAPHIC ACTIVITIES Cecelia Jankowski PRESIDENT-ELECT Toshio Fukuda +1 732 562 5504, [email protected] Jones, a freelance journalist in Helsinki, reports TREASURER Joseph V. Lillie SECRETARY Kathleen A. Kramer STANDARDS ACTIVITIES Konstantinos Karachalios on China’s sizzling private space industry for PAST PRESIDENT James A. Jefferies +1 732 562 3820, [email protected] this issue [p. 6]. He was captivated by planets VICE PRESIDENTS Witold M. Kinsner, Educational Activities; Hulya Kirkici, EDUCATIONAL ACTIVITIES Jamie Moesch and rockets as a kid but pursued other interests Publication Services & Products; Francis B. Grosz Jr., Member +1 732 562 5514, [email protected] professionally. The arrival of his first child & Geographic Activities; K.J. “Ray” Liu, Technical Activities; GENERAL COUNSEL & CHIEF COMPLIANCE OFFICER rekindled his early love for space. Today, he writes Robert S. Fish, President, Standards Association; Thomas M. Sophia A. Muirhead +1 212 705 8950, [email protected] Coughlin, President, IEEE-USA CHIEF FINANCIAL OFFICER & about it exclusively. His 9-year-old daughter, Lilja, DIVISION DIRECTORS ACTING CHIEF HUMAN RESOURCES OFFICER aspires to be the first Finnish citizen on Mars, Renuka P. Jindal (I); David B. Durocher (II); Sergio Benedetto Thomas R. Siegert +1 732 562 6843, [email protected] while 6-year-old Saima says she would rather (III); John P. Verboncoeur (IV); John W. Walz (V); Manuel Castro TECHNICAL ACTIVITIES Mary Ward-Callan stay home and run mission control. (VI); Bruno Meyer (VII); Elizabeth L. “Liz” Burd (VIII); Alejandro +1 732 562 3850, [email protected] “Alex” Acero (IX); Ljiljana Trajkovic (X) MANAGING DIRECTOR, IEEE-USA Chris Brantley REGION DIRECTORS Babak Dastgheib-Beheshti (1); Wolfram Bettermann (2); +1 202 530 8349, [email protected] Gregg L. Vaughn (3); David Alan Koehler (4); Robert C. Shapiro (5); Keith A. Moore (6); Maike Luiken (7); IEEE PUBLICATION SERVICES & PRODUCTS BOARD Vaclav Smil Magdalena Salazar-Palma (8); Teófilo J. Ramos (9); Hulya Kirkici, Chair; Derek Abbott, Petru Andrei, Smil, a Distinguished Professor Emeritus at the Akinori Nishihara (10) John Baillieul, Sergio Benedetto, Ian V. “Vaughan” Clarkson, DIRECTOR EMERITUS Theodore W. Hissey Eddie Custovic, Samir M. El-Ghazaly, Ron B. Goldfarb, University of Manitoba, in Canada, studies and Larry Hall, Ekram Hossain, W. Clem Karl, Ahmed Kishk, writes about energy, manufacturing, invention, and IEEE STAFF Aleksandar Mastilovic, Carmen S. Menoni, Paolo Montuschi, demographics. “I’ve read nearly all of his 37 books,” EXECUTIVE DIRECTOR & COO Stephen Welby Lloyd A. “Pete” Morley, George Ponchak, Annette Reilly, Bill Gates tweeted last year. The count actually +1 732 562 5400, [email protected] Sorel Reisman, Gianluca Setti, Gaurav Sharma, Maria Elena CHIEF INFORMATION OFFICER Cherif Amirat stands at 40, including Energy and Civilization: +1 732 562 6017, [email protected] Valcher, John Vig, Steve Yurkovich, Bin Zhao, Reza Zoughi A History (MIT Press, 2017). Smil is the author of IEEE OPERATIONS CENTER PUBLICATIONS Michael B. Forster IEEE Spectrum’s Numbers Don’t Lie column, a data- +1 732 562 3998, [email protected] 445 Hoes Lane, Box 1331 CHIEF MARKETING OFFICER Karen L. Hawkins Piscataway, NJ 08854-1331 U.S.A. centric look at technological trends. This month +1 732 562 3964, [email protected] Tel: +1 732 981 0060 Fax: +1 732 981 1721 he takes on the limits to human longevity [p. 21].

SPECTRUM.IEEE.ORG | MAY 2019 | 03 SPECTRAL LINES_ 05.19

CELL FOR SALE: A Kenyan market sells mobile phones, which are ubiquitous in sub-Saharan Africa.

policies for information and communications technology to enable a single digital marketplace across the continent. Some governments are particularly aware of the need for more in-country engineering expertise. IEEE is currently concentrating its efforts in five nations— Ghana, Kenya, Rwanda, Uganda, and Zambia—all of which have long-term development plans emphasizing science and technology. These plans call for building human capital in the form of well-trained scientists and engineers, in addition to building fiber-optic broadband networks and clean power plants. Rwanda is the focus of “The Blood Is Here,” in this issue. The Rwandan gov- Engineering Change in Africa ernment is trying to modernize its high- way infrastructure, but it will be a long Facing urgent needs, African nations process; currently, narrow roads wind are pioneering new technologies through the hilly terrain. R wandan hospitals needing emergency supplies find y 2022, forecasters estimate that sub-Saharan Africa will have that truck deliveries are often too slow for patients nearly 1 billion mobile phones—enough for the vast majority who require urgent care. of the projected 1.2 billion people who will live there. What it To address this need, a drone company called won’t have are the endless streams of telephone poles and wires Zipline is providing air deliveries of blood to hos- that cascade across other continents. Development experts call pitals all across the country, and will soon begin this an example of a “leapfrog technology.” By going straight delivering other lightweight medical supplies as to mobile, many African nations will be able to skip the step of well. While Zipline hails from California, it’s dedi B building extensive and expensive landline infrastructure. ¶ In fact, cated to building up local engineering capacity, and “some places will go straight to 5G,” says V incent Kaabunga, chair of the offers extensive training and professional develop- IEEE Ad Hoc Committee on Africa, which has helped craft IEEE’s strat- ment to its employees in Rwanda. And Zipline is egy to increase engineering capacity on the continent. With this kind of not an anomaly. A vibrant drone startup scene has leapfrogging, African nations can take the lead in certain types of tech- arisen in East Africa, with local companies finding nological development and deployment, he says. Just look at mobile applications in agriculture, road surveying, min- money: Companies such as M-Pesa sprang up to solve a local problem— ing, and other areas. people’s lack of access to brick-and-mortar banks—and became a way for Zipline is now expanding its drone delivery ser- people not only to make payments, but also to get loans and insurance. vices to Ghana. It’s not yet clear how successful the “We’ve refined the concept of mobile money over the last 10 or 15 years,” company will be in its attempt to scale up its opera- says Kaabunga, “while other parts of the world are just now coming tions. Zipline’s financials are opaque, and its busi- around to embracing it.” ¶ IEEE and its members in Africa are facilitat- ness model may not be viable without government ing the application of new technologies by promoting education and subsidies. But the company is now working on a access, says Kaabunga, who also works for a technology consulting firm demonstration project in North Carolina. Whether in Kampala, Uganda. The IEEE in Africa Strategy, launched in 2017, calls or not medical drone delivery works out in the for IEEE to support engineering education at every level and to advise long run, one thing is certain: Africa is trying it first. government policymakers, efforts that Kaabunga and his colleagues in —Eliza Strickland the region have already begun. For example, they’re currently working

with the Smart Africa alliance, an initiative that aims to create standard ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/africa0519 IMAGES IMO/PHOTOTHEK/GETTY THOMAS

04 | MAY 2019 | SPECTRUM.IEEE.ORG Hearing aids can’t solve the cocktail party problem...yet.

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comsol.blog/cocktail-party-problem In the early years of TEST RUN: During a test in March, rocketry at Caltech, LinkSpace’s reusable rocket, PRIVATE called NewLine Baby, hovered for there was no figure more 10 seconds and landed safely. influential than the ROCKETS Chinese cyberneticist Qian Xuesen. Then, in 1955, the United States repatriated him to China, suspecting him READY FOR of being a spy. Qian returned to China to become the father of the country’s space-launch vehicle and ballistic-missile programs LIFTOFF IN and contributed greatly to the “Two Bombs, One Satellite” nuclear weapons and space project. And his efforts were CHINA not wasted—on 9 March of this year, the People’s Republic of China launched its 300th Long March rocket, which put China’s 506th spacecraft into orbit. Four Chinese companies To do more exploration at a lower cost, the Chinese vie to be the first to government has initiated policies aimed at establishing

achieve orbit a private space industry like the one that exists in the LINKSPACE

06 | MAY 2019 | SPECTRUM.IEEE.ORG United States, where companies such The company has moved on to develop tourism services. “The whole launch- as SpaceX, Blue Origin, and Rocket Lab a much larger and more capable two- vehicle ecosystem is getting more and are bringing low-cost launch services stage launch vehicle powered by liquid more complete,” he notes. to the space sector. methane and liquid oxygen. It hopes While Chinese firms race to reach In 2014, China’s State Council issued a to carry out the maiden flight of the orbit and score commercial contracts to proposal called Document 60 that would Zhuque-2 in 2020 and plans to eventu- launch constellations of r emote‑sensing open the nation’s launch and small satel- ally make the rocket reusable, though and communications satellites, these lite sectors to private capital. The govern- doing so will reduce lift capability. companies will also help China drive ment followed this announcement with Meanwhile, LinkSpace Aerospace down launch costs, and make more mis- helpful policies, including a national civil- Technology Group, founded in 2014, sions possible with fewer resources. military integration strategy to transfer has set its sights on building an orbital “If the entire world is moving in the crucial, complex, and sensitive technolo- launch vehicle capable of vertical take- direction of lower-cost, reusable, com- gies from state-owned space sector giants off and landing, as demonstrated by mercially driven launch systems, anyone to startups approved by authorities. SpaceX’s Falcon 9. The company wants who does not keep up with this devel- Today, more than 10 private launch to have a maiden flight of the liquid- opment may find themselves out of the companies in China are working on propellant launcher NewLine-1 in 2021, game,” says John Horack, a professor of launch vehicles or their components, after testing its NewLine Baby suborbital mechanical and aerospace engineering and four are now prepared to make their rocket throughout this year. at Ohio State University. first attempts to reach orbit. Lan Tianyi, founder of Ultimate That these companies have come so far Two Beijing-based companies, Blue Nebula Co., a space consultancy so quickly is an indicator of the level of OneSpace and iSpace, are close to put- in Beijing, says China’s launch com- state support for aerospace in China, and ting small satellites into orbit with their panies each have different goals and a sign that this mature industry is full of own rockets. The first OneSpace OS-M1 capabilities. Some firms are focusing expertise. But the question of whether or rocket failed around one minute after on developing launchers powered by not private launch firms are truly ready launch from Jiuquan Satellite Launch solid fuel, while others opt for liquid for takeoff can be answered only on the Center in the Gobi Desert on 27 March propellants, which may allow the rock- launchpad. —Andrew Jones and, at press time, the iSpace Hyperbola-1 ets to be reused. Some are also explor- ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/ was expected to follow up with its own ing creative options to provide space chinaspace0519 attempt at Jiuquan as early as April. Both launch vehicles are relatively small and use a pre- Countdown to Launch Four space launch companies in China aim to demonstrate their systems in the next two years mixed solid combination of fuel and oxidizer, which is cheap, reli- Firm Founded Launch Propellant Payload to First able, and simple to make but less vehicle orbit launch efficient than liquid fuel. LandSpace Technology Corp. iSpace 2016 Hyperbola-1 Solid 300 kilograms April 2019 made the first private Chinese to 300 kilo- (expected as orbital launch attempt in Octo- meters low of press time) ber using a solid-propellant Earth orbit rocket. After successful burns LandSpace 2015 Zhuque-1 Solid 300 kg to 300 October 2018 and separations of the first and km LEO (failed) second stages, a problem with Zhuque-2 Liquid 4,000 kg to 2020 the rocket’s third stage saw the 200 km LEO Zhuque-1 rocket and its small LinkSpace 2014 NewLine-1 Liquid 200 kg to 2021 satellite payload fall from an 500 km sun- synchronous apogee of 337 kilometers into orbit the Indian Ocean. It reached a OneSpace 2015 OS-M1 Solid 205 k g to 300 March 2019 top speed of 6.3 kilometers per km LEO (failed) second, just shy of the 7.9 km/s required to achieve orbit.

NEWS

SPECTRUM.IEEE.ORG | MAY 2019 | 07 TOO LITTLE, TOO LATE: Technicians install a portion of Australia’s National Broadband Network, which is behind schedule and over budget.

The reason an FTTN network theo- retically costs less is because there’s less fiber to install. Rather than run fiber to every premise, FTTN runs fiber to cen- tralized “nodes,” from which any number of technologies can then connect to individual premises. Fiber could be used, but more typically these last-mile connections are made with copper cabling. The rationale behind the FTTN pivot was that there’s no need to lay fiber to homes and offices because copper land- lines already connect those buildings. Unfortunately, copper doesn’t last for- AUSTRALIA’S ever. “A lot of the copper is very old,” says Mark Gregory, an associate professor of engineering at RMIT Univer- FIBER-OPTIC MESS sity, in Melbourne. “Some of it is just not suitable for fiber to the node.” Gregory The National Broadband Network is delivering says that NBN Co. has run into delays slower service to fewer properties than promised more than once as it encounters copper cabling near the end of its usable life and must replace it. On 18 May, voters in “None of the promises have ever been NBN Co. has purchased roughly Australia’s federal election met,” says Rod Tucker, a telecommuni- 26,000 kilometers of copper so far to will determine whether the cations engineer and professor emeri- construct the network, according to Liberal-National Coalition tus at the University of Melbourne. The Gregory—enough to wrap more than will remain in control or the Australian watershed moment for the network was halfway around the Earth. Buying that Labor Party will win the government. the 2013 federal election. That year, the copper added roughly AU $10 billion to Either way, the new leaders will have to Labor government that had champi- the FTTN price tag, says Tucker. On top contend with the National Broadband oned the network was replaced by a of that, NBN Co. is paying AU $1 billion a Network (NBN), a lumbering disaster that conservative coalition government. The year to Telstra, the Australian commu- began as an ambitious effort by the Aus- new government promptly reevaluated nications company, for the right to use tralian government to construct a coun- the NBN plan, taking issue with its pro- the last-mile copper that Telstra owns. trywide broadband network. jected cost. But perhaps the worst part is that even When the NBN was first proposed in The original plan, estimated to cost after the cost blowouts, the lackluster April 2009, the government aimed to AU $43 billion, was a fiber-to-the-premise connections, and the outdated copper build a fiber-optic network that would (or FTTP) plan. FTTP, as the name technology, there doesn’t seem to be deliver connections of up to 100 megabits implies, requires threading fiber-optic a good path forward for the network, per second to 90 percent of Australian cable to each and every building. The which will be obsolete upon arrival. “In homes, schools, and workplaces within coalition government balked at the terms of infrastructure,” says Gregory, eight years. A decade later, however, the price tag, fired NBN Co.’s CEO, restruc- “it’s pretty well the only place I know of NBN has failed to deliver on that prom- tured the company, and proposed an that’s spent [AU] $50 billion and built ise. NBN Co., the government-owned alternative fiber-to-the-node (or FTTN) an obsolete network.” company created to construct and man- strategy, which was estimated to cost Upgrading the network to deliver the age the network, now expects to deliver no more than AU $29.5 billion. The original connection speeds will require 50 Mb/s connections to 90 percent of the cost has now ballooned to more than yet another huge investment. That’s

country by the end of 2020. AU $51 billion. because copper cables can’t compete NBN

08 | MAY 2019 | SPECTRUM.IEEE.ORG with fiber-optic cables. To realize 100 Mb/s, NBN Co. will THWARTING CYBERATTACKS eventually have to lay fiber NEWS from all the nodes to every ON MEDICAL IMPLANTS premise anyway. Gregory, for one, estimates that could Medtronic recently disclosed medical device cost NBN Co. an additional vulnerabilities; Purdue University scientists AU $16 billion, a hard num- have proposed a countermeasure ber to swallow for a project that’s already massively over budget. “Fiber to the node is a The U.S. Department of Homeland fast heart rhythms. External comput- dead-end technology in that Security and the U.S. Food and ers program the devices and retrieve it’s expensive to upgrade,” Drug Administration warned in March information about their performance. says Tucker, who also wrote that numerous medical devices made by Such devices emit radio-frequency sig- about the challenges the NBN Medtronic are vulnerable to cyberattack. nals that can be detected up to several would face in the December The vulnerabilities affected nearly 20 meters from the body. A malicious indi- 2013 issue of IEEE Spectrum. of the company’s implantable cardiac vidual nearby could conceivably hack After the federal election, device models and the external equip- into the signal to jam it, alter it, or snoop the incoming government ment used to communicate with them. on it, according to the DHS warning. will have to figure out what A Medtronic spokesperson said that Signals that are unencrypted, as were to do with this bloated proj- the company voluntarily disclosed the those produced by Medtronic’s devices, ect. NBN Co. is far from profit- vulnerabilities to the Department of are easy to intercept, says Shreyas Sen, able, and even if it was, it still Homeland Security (DHS), and that “no an electrical and computer engineer owes billions of dollars to the cyberattack, privacy breach, or patient at Purdue University. “It would be like Australian government. If the harm has been observed or associated sitting in a room listening to someone government does decide to with these issues.” speaking in plain language,” he says. bite the bullet and upgrade to At risk are certain models of heart- For more than a decade, researchers FTTP, it will have to contend regulating devices: implantable cardiac have repeatedly warned that medical with other commercial net- resynchronization therapy/defibrillators devices could be turned into murder works now delivering equiv- (CRT-Ds) and implantable cardioverter weapons. Scientists have demonstrated, alent speeds. defibrillators (ICDs). CRT-Ds send elec- in written reports and at conferences, Had Australia delivered the trical impulses to the lower chambers how to hack into an insulin pump, a pace- NBN as originally promised, it of the heart to help them beat together maker, or even an entire hospital network. would have been one of the in a more synchronized pattern. ICDs Medtronic is one of several compa- fastest, most robust national deliver electrical impulses to correct nies over the last few years to publicly networks in the world at the time. Instead, the country has watched its place in rankings of broadband speeds around the world continue to drop, says Tucker, while places like New Zealand, Austra- lia’s neighbor “across the ditch,” have invested in and largely completed robust FTTP networks. “It was an opportunity lost,” says Gregory. —Michael Koziol

↗ POST YOUR COMMENTS at https://

MEDTRONIC spectrum.ieee.org/australiabroadband0519

AT RISK: Nearly 20 cardiac devices made by Medtronic, including the two shown here, have vulnerabilities that could be exploited in a cyberattack.

SPECTRUM.IEEE.ORG | MAY 2019 | 09 disclose weaknesses in the that uses a particular cybersecurity of its medical low-frequency range to con- X-RAY DETECTION devices. In 2017, Smiths Med- fine within the human body all ical disclosed, through DHS, of the communication signals that its wireless drug pump, coming from a medical device. MAY BE typically used in hospitals, The signals create what’s could be hacked remotely. known as an e lectro-quasistatic PEROVSKITES’ The same year, the U.S. field using the body’s conduc- Food and Drug Administra- tive properties. Signals from tion (FDA) notified the public a pacemaker, for example, KILLER APP of vulnerabilities in St. Jude can travel from head to toe, Medical’s implantable cardiac but they won’t leave the skin. The wonder crystal could yield devices, including pacemak- “Unless someone is physically imagers that are far more sensitive ers, defibrillators, and resyn- touching you, they don’t get than commercial detectors chronization devices. An the signals,” Sen says. attacker could crash a breath- Sen and his colleagues call ing therapy machine made by it electro-quasistatic human The crystalline material known as BMC Medical and 3 B Medical, body communication, and perovskite makes for a superefficient DHS warned in 2017. have described it in the jour- photovoltaic cell. Researchers are also DHS’s Cybersecurity and nal Scientific Reports. In their exploring perovskites’ potential in Infrastructure Security study, Sen’s prototype success- transistors and LED lighting. But there’s yet another Agency (CISA) started tracking fully confined signals from a use for this wonder crystal, and it may be the most medical device vulnerabili- wearable device to the body. promising of all: as X-ray detectors. ties in 2013. The agency issued (And there’s a bonus: Signals in Dozens of groups around the world are exploring only seven advisories over the the e lectro-quasistatic range this area, and major X-ray imaging manufacturers, first five years, a CISA spokes- use a fraction of the energy including Samsung and Siemens, are considering person told IEEE Spectrum. of traditional Bluetooth perovskite for their next-generation machines. Com- That number jumped to 16 in communication.) pared with today’s X-ray imagers, detectors based fiscal year 2017 and 29 in fis- The researchers have not on perovskite compounds are far more sensitive cal 2018. The FDA and DHS in yet tested their prototype on and use less power. And for certain applications, the October announced a frame- people with an implanted materials can be tuned to emit color when irradiated. work to coordinate their medical device. Medtronic, What makes perovskites so useful for X-ray detec- response to medical device for its part, is developing a tion is the same thing that makes them good for solar cybersecurity threats. series of software updates cells: They’re excellent at converting light into elec- No known attack on a life- to better secure the wireless trical charge. In a direct detector, X-ray photons are supporting medical device has communication affected converted into electrons inside a semiconductor. In actually occurred, makers of by the issues described in a scintillator imager, the X-ray photons are first con- such machines often point out. the advisory, according to verted into visible light, which is then converted into And encrypting the signals on a spokesperson. The first electrons. Compared with conventional versions of these devices should provide update is scheduled for later these digital X-ray machines, lab prototypes that use reasonable protection. But in 2019, subject to regula- various perovskites are at least 100 times as efficient. Sen, at Purdue, says encryp- tory approvals. Medtronic In one experiment, Xiaogang Liu’s group at the tion isn’t enough. “The physi- and the FDA recommend National University of Singapore started with a cal signals are available, and that patients and physicians commercial flat-panel X-ray detector that used bulk we are not good with using continue to use the devices. scintillators of cesium iodide thallium. The group passwords,” he says. —Emily Waltz removed the CsI(TI) layer and replaced it with a layer To thwart would-be of nanocrystals of cesium lead bromide—an inor- attackers, Sen and his col- A version of this article appears ganic perovskite—directly coating them onto photo leagues have designed a on our Human OS blog. diode arrays. When coupled with p hotomultiplier countermeasure: a device tubes, the resulting device had a detection limit that ↗ POST YOUR COMMENTS at https:// worn around the wrist spectrum.ieee.org/medtronic0519 was just 1/400 that of medical X-ray machines, as the

10 | MAY 2019 | SPECTRUM.IEEE.ORG There are still a number of hurdles to cross before perovskite scintillators or direct X-ray imagers will be ready for market. A big obstacle is that some perovskites are sensitive to moisture. Liu has developed a method for coating each nanocrystal with silicon dioxide and is exploring other protective methods. Perovskite layers can also be encapsulated in glass, much like traditional solar cells are. But in general, perovskite X-ray imagers won’t need to be quite as hardy as perovskite PVs or LEDs, because the environmental conditions they’ll face are more benign. Solar panels need to perform even after being exposed to the elements for 20 years, while LEDs are exposed to heat and, of course, light, both of which can degrade a perovskite compound. X-ray machines, by contrast, are typically used in climate-controlled settings. For that reason, both Liu and Huang believe perovskite X-ray detectors will be commercialized much more quickly than other perovskite applications. Huang predicts that perovskite detec- group reported in Nature last September. BETTER DETECTORS: Perovskite nanocrystals tors will open up new applications for Several X-ray manufacturers are now developed by Xiaogang Liu [top right] and Qiushui X-rays, expanding what’s already a Chen [top left] at the National University of testing nanocrystal scintillators using Singapore absorb X-rays better than conventional multibillion-dollar industry. More efficient his group’s approach, Liu says. materials do. The nanocrystals can be fine-tuned imagers would draw less power, lending Liu credits grad student Qiushui Chen to emit colors when irradiated [bottom]. themselves to portable machines that run for coming up with the idea of using on batteries. Liu’s group has also demon- perovskite nanocrystals in this way. “A North Carolina at Chapel Hill have been strated a variety of tunable, color-emitting lot of our recent work involves rare-earth studying direct X-ray detectors based perovskite nanocrystals. That work could materials, which is what conventional on perovskites since 2014. (Huang also lead to multicolor X-ray displays, which scintillators use,” Liu says. To form the works on perovskite photovoltaics.) In are impossible with today’s scintillator perovskite layer, the researchers mixed one experiment, they coated methyl- X-ray machines. the nanocrystals with liquid cyclohexane ammonium lead tribromide—a common And because they use flexible substrates, and then spin-coated the mixture onto a perovskite compound—onto a regular perovskite imagers could conform to what- flexible substrate. X-ray detector that used amorphous sili- ever’s being scanned; anyone who has “We got a little bit lucky, because we con to convert the X-rays to electrons. The experienced the discomfort of a mammo- discovered that the nanocrystals had to addition of the perovskite layer made it gram will appreciate that feature. Faster, be deposited on the substrate through 3,000 times as sensitive. more sensitive imagers would also reduce a solid-state process,” Liu says. “If the “When you want extremely efficient and the radiation from dental and medical particles are dispersed in solution, it’s sensitive detectors, you need to count sin- X-rays and airport security scanners. no good.” gle photons, and that’s not easy,” Huang “Once we can make X-rays much safer, Researchers have also demonstrated explains. “We showed that we can make the market will change because you’ll be perovskites in direct X-ray detectors materials that allow you to distinguish the able to put the detectors everywhere,” with vastly superior performance to signal from the noise.” Huang recently Huang says. —Jean Kumagai that of commercial imagers. Jinsong created a startup to commercialize radia- ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/

NATIONAL UNIVERSITY OF SINGAPORE (2) SINGAPORE OF UNIVERSITY NATIONAL Huang and his group at the University of tion detectors based on his group’s work. perovskitexray0519

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SPECTRUM.IEEE.ORG | MAY 2019 | 11 12 | MAY 2019 | SPECTRUM.IEEE.ORG PHOTOGRAPH BY Armin Weigel/picture alliance/Getty Images FARES GOING UP

AT THE HEIGHT OF rush hour, when traffic is congested, you can make it to Manhattan’s West Side from IEEE Spectrum’s East Side offices faster on foot than it takes the city bus to get there. Taxis get caught in gridlock too. But a new type of taxi will soon operate above the fray. The CityAirbus vertical- takeoff-and-landing aircraft can swoop down, pick up as many as four passengers, and cruise at speeds up to 120 kilometers an hour. The flying taxi, scheduled to make test flights this year, is held aloft by four ducted fans, each with a pair of propellers that are turned by separate 100-kilowatt electric motors. The eight motors draw power from four batteries whose combined capacity is 110 kilowatt-hours— enough energy for 15 minutes of flight time between charges.

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JOE DIPRIMA THIS ENGINEER HURLS MUSICAL LIGHTNING BOLTS

f you’ve ever wanted to music through so-called singing Tesla GOING TO ELEVEN: ArcAttack makes its own Tesla play guitar while giant bolts coils, in which the long sparks from a coils to produce giant sparks for live performances— I and a wearable Faraday cage to perform in. of lightning ground them- coil are modulated at audible frequen- selves around you—and to you—then cies by square waves. The result is spec- ist Viktoria Modesta to create a hollow Joe DiPrima can hook you up. DiPrima tacular, if perhaps not terribly melodious. prosthetic leg for Modesta that was fitted is the cofounder of ArcAttack, a small DiPrima sometimes wears a suit that is a with spark gaps, for a Rolls-Royce commer- Austin, Texas–based performance and full-body Faraday cage, allowing him to cial. Driving the spark gaps required fabricat- design group that specializes in the fun play a special guitar while being struck by ing a miniature Tesla coil that could be fitted things you can do with high-voltage bolts from two giant Tesla coils. into the heel of a customized shoe. Tesla coils. DiPrima also designs and builds Tesla- DiPrima doesn’t have a formal engineering

RESOURCES_GEEK LIFE “We do a lot of random things,” says coil demonstration systems for muse- education. “I was interested in electronics by DiPrima, with a chuckle, “Every year ums and the like: “We have a system at the time I was very young. My dad helped me— we go on a fall and spring tour, usually. the Orlando Science Center [in Florida], he was a biomedical technician, so I got experi- We’ll go into theaters and schools and and the Rochester Science Center ence doing [things] like soldering,” says DiPrima. do an hour-long science show, and [in New York], and the Liberty Science In his teens DiPrima “put down electronics for a then we do lot of public shows in con- Center in New Jersey,” says DiPrima. bit and got into computers because it was the junction with those.” Most recently, DiPrima and his ’90s—all the cool stuff was happening with To get a flavor of ArcAttack’s shows, brother (and ArcAttack cofounder) computers at the time...just writing programs you can visit the group’s YouTube John worked for fashion-tech designer purely for my own pleasure, when I was sup-

ARCATTACK channel and see and hear how they play Anouk Wipprecht and bionic pop art- posed to be doing my schoolwork!”

SPECTRUM.IEEE.ORG | MAY 2019 | 15 RESOURCES_HANDS ON

When he finished high school, DiPrima took a job repairing tele- TAKING AI visions and other consumer elec- TO THE EDGE tronics, which turned out to be an education in itself. “You get to GOOGLE’S see how everybody screwed up. I TPU NOW think it’s a pretty in valuable lesson. You know what RCA did wrong.... COMES IN You know what Samsung got A MAKER- wrong every time.... Things are super-refined now, but back in FRIENDLY the day everything had some pe- PACKAGE culiar glitch or problem.” When the TV repair business dried up because it became cheaper to replace a TV than fix one, DiPrima worked at a music store repairing gui- here’s a steady drumbeat tar amplifiers—“people will T about how deep learning is go- still pay $150 to repair a $900 ing to touch nearly every area of Marshall amp,” he says—before technology, not least from us here at IEEE getting a job around 2005 at the Spectrum. So, like a lot of folks, I’ve been in- University of Texas doing work terested in getting my hands dirty and learn- like designing and building lec- ing some of the tools and techniques. But, terns in classrooms. like a lot of folks, I’ve been stymied by the from sample data sets to determine what That’s when he and his brother difficulty of getting up and running. output should correspond to a given input. got interested in Tesla coils. “We I’ve tried to use TensorFlow—Google’s The TPU is designed for the performance started building our own Tesla open-source machine-learning library— phase, when systems with compiled mod- coils for the sole purpose that we and Keras, another library that acts as a els are presented with real-world data and wanted them to be musical instru- high-level interface between Python pro- are expected to behave appropriately using ments. We posted some [YouTube grams and machine-learning back ends like a version of TensorFlow called T ensorFlow videos] as a kind of a hobby.” The TensorFlow. But it’s been a discouraging ex- Lite. In this Hands On, I’m going to be focus- videos started attracting an au- ercise in going down software-dependency ing on the Dev Board’s hardware and setup, dience and the brothers started rabbit holes and sifting through fragmented and in a later article I will dive deeper into performing live shows. Eventu- and often obsolete documentation. And using models and interfacing with some ex- ally, they realized they were mak- then, just when everything finally seems to ternal hardware. ing more money doing things like be working, something breaks thanks to a The Dev Board is designed to make hard- selling T-shirts at their shows system upgrade. As the old hacker lament ware experimentation easy, with a Pi-like than they were earning from their goes, “You are in a maze of twisty little pas- general-purpose input/output (GPIO) con- day jobs, and they took the plunge sages, all alike.” nector, SD-card reader, HMDI video output, and formed ArcAttack as a full- Then Google offered a way out of the a Wi-Fi radio, an Ethernet port, a port for time occupation. maze, with the US $150 Coral Dev Board. attaching a camera module, and a USB DiPrima continues to spend The Dev Board looks a lot like a Raspberry Pi, port for peripherals. Like the Pi 3, it has a lot of his time reading and re- albeit one with a great big heat sink bolted 1 gigabyte of RAM and uses an Arm-based searching for his projects. “I kind on top. But under that heat sink is a system- processor as its CPU. of regret now that I didn’t have on-module built to support Google’s Edge There are differences, however: The Dev more college education, but at Tensor Processor Unit (TPU). Board’s GPIO pinout is similar to the Pi’s, but the same time I feel like I have a The TPU is a coprocessor optimized for there are fewer general-purpose pins avail- pretty solid foundation of engi- handling neural networks, intended to able because the Dev Board’s GPIO also neering knowledge,” he says. push artificial intelligence out from central- supports things like a serial audio interface. —STEPHEN CASS ized clouds to embedded devices. It’s not Other differences include the presence meant for the actual learning phase of ma- of 8 GB of onboard flash storage, which POST YOUR COMMENTS at https://spectrum.

ieee.org/diprima0519 chine learning, when models are compiled hosts the operating system. This leaves the (3) KLETT RANDI

16 | MAY 2019 | SPECTRUM.IEEE.ORG There’s also only one USB-A port, com‑ tions for attaching the specially designed pared with the Pi 3’s four. The paucity of camera module Google provided. USB-A ports is because Google envisions I used a Raspberry Pi as my front-end the Dev Board being used to prototype em‑ Linux computer for the setup and was quickly bedded devices, so there’s less need to able to download to the Dev Board the pre‑ support peripherals (to that end, the core compiled models required for some demos. system-on-module can be detached so that Once everything was running, I also had no a device maker can provide its bespoke sup‑ problem SSHing in from my MacBook Pro. porting hardware). Instead the board pro‑ There are two camera demos, both of which vides a lot of support for headless operation, use live video: One can detect when faces sans keyboard and screen. come into view, while the other can recognize The board has a Micro-USB port for a ded‑ a somewhat eclectic collection of 1,000 ob‑ icated serial console interface, which can jects, including “coffee mug,” “garbage truck,” be used to monitor the system and super‑ and “European fire salamander.” Bounding vise flashing an OS (a customized version of boxes (for faces) or text labels (for objects) are Debian Linux called Mendel) to the onboard overlaid on the video feed. Google gives in‑ storage. There’s a second USB-C port, in‑ structions on how to stream the overlaid feed tended for connecting the board to a ma‑ to your front-end computer, but I didn’t have chine running Linux. From there, users are much luck in getting smooth results. However, expected to use the SSH protocol to log in with a monitor plugged directly into the Dev to the Dev Board for normal use. Board it ran impressively well. Because of my prior experience with ma‑ In addition to the camera-demo data, chine learning, I was a little apprehensive Google offers a small selection of other when I unwrapped my Dev Board, not least models that can be used with a Python ap‑ SD‑card reader free for additional storage, because it was a preproduction unit, where plication programming interface (API) to unlike the Pi’s r eader, which is reserved for rough edges often abound. communicate with the TPU, and it’s possi‑ the OS. The board is powered via a USB-C But I needn’t have worried. An insert di‑ ble to create and upload your own. However, connector instead of a Micro‑USB connec‑ rected me to a Web address to get started. currently the Python API is limited to pro‑ tor. And be warned: Google recommends I was pleasantly surprised to find a set of cessing static images rather than the cam‑ using a 2- to 3-ampere 5-volt power sup‑ well-illustrated step-by-step instructions era feed. At press time, the Dev Board team ply, while many USB power adapters top out (albeit for folks comfortable with using a said they were considering releasing an ex‑ at 1.5 amps. command-line interface), including direc‑ tended API, which I hope to use as the basis for my follow-up article. I can finally see the maze’s exit. REAL-TIME RECOGNITION: For one demo, I put a picture of a salamander on my iPhone’s screen. When —STEPHEN CASS I held the Dev Board’s camera module so that the onscreen salamander filled the view, the board took just a few milliseconds to identify it. As I pulled the module back so that the iPhone’s body came into view, the POST YOUR COMMENTS at https://spectrum.ieee.org/ board instantly corrected its guess about what it was seeing, despite the salamander still being prominent. devboard0519

SPECTRUM.IEEE.ORG | MAY 2019 | 17 RESOURCES_CAREERS

location can be an important factor in other areas of expertise beat blockchains. In WHAT what’s most in demand. the San Francisco Bay Area, engineers work- EMPLOYERS Online job-search firm Hired took a ing in search command higher salaries (shall look at the 2018 data from its job sites we call that the Google effect?). In New York WANT FROM around the world to capture a snap- City, the biggest salaries are going to gam- CODERS shot of demand for software engineers ing engineers. And in Toronto, the top sala- through the metric of the salaries they ries are going to engineers with experience IN-DEMAND are commanding in different roles. The in natural-language processing. JOB SKILLS VARY company also estimated the gap be- With regard to programming languages, the tween what programming languages winner, globally, was Google’s Go—probably BY REGION employers were looking for versus what because developers are in such short supply. languages coders are actually familiar That programming language is used by only with: Hired looked at the number of in- 7 percent of the job seekers on Hired’s site. aving sought-after skills is terview requests received by job seekers list- It’s also a good time to be working with Scala; H critical to any engineer’s career. ing experience with a given language. that’s No. 2 in terms of employer desire, yet And if such skills are relatively rare In both cases, some interesting patterns only 3 percent of developers surveyed listed in the talent pool, that can make all the differ- emerged (top results are listed in the tables it as their primary language. —TEKLA S. PERRY ence when it comes to negotiating salary or below). Demand for engineers with block- perks. While some general rules apply—no chain experience is booming, with strong Extended tables are available online in our one needs any new punch-card operators— salaries seen everywhere. But in some cities, View From the Valley blog.

Rank and Average Salaries (US $) for Engineers, 2018

Role San Francisco New York City Toronto London Paris Demand Bay Area Salary/rank Salary/rank Salary/rank Salary/rank growth Salary/rank 2018 over 2017

Search $157,000 1 $129,0007 $64,000 12 $86,000 5 $61,000 4 Info not available

Security $156,0002 $117,00011 $75,000 4 $86,000 5 $61,000 4 132%

Blockchain $155,0003 $137,0002 $79,000 3 $89,000 2 $67,000 1 517%

Natural- language $155,0003 $114,000 12 $83,000 1 $84,000 7 $59,000 7 Info not available processing

Machine learning $153,0005 $122,00010 $80,000 2 $87,000 3 $65,000 2 27%

Embedded $150,0007 $124,0009 $74,000 5 $90,000 1 $58,000 9 75%

Gaming $145,000 10 $147,000 1 $73,000 7 $81,000 8 $61,000 4 Info not available

Most Sought-After Programming Languages, 2018

Skills San Francisco New York City Toronto London Paris Developers Bay Area with that language

1. Go 3 2 8 1 3 7%

2. Scala 4 7 13 14 2 3%

3. Ruby 2 1 2 15 4 10%

4. TypeScript 1 5 1 2 1 12%

5. Kotlin 5 10 12 8 9 2% SOURCE: HIRED SOURCE:

18 | MAY 2019 | SPECTRUM.IEEE.ORG POST YOUR COMMENTS at https://spectrum.ieee.org/jobskills0519 RESOURCES_STARTUPS

into the tiny microchambers, each with a vol- ISOPLEXIS ume of about a nanoliter. SOFTWARE AND At the chip’s proof-of-concept phase, it took a week to manually count the cells and analyze MICROELECTRONICS FABRICATION the data. IsoPlexis hired P atrick Paczkowski TECHNIQUES FIGHT CANCER as vice president of software to turn the company’s data-pr ocessing and bioinformatics software into a fully aut omated commercial product. Like Mackay, Paczkowski had a degr ee that had nothing to do with biology, but he wanted to create better algorithms to analyze the cells. This and other engineering efforts led to the IsoLight system, which can complete automated image processing and data-quantification analytics in a few hours. The technology is not limited to onc ology. The company began working in that field partly based on the founders’ research focus and because funding for cancer research is more plentiful than for other diseases. Mackay says the technology can be used for research, and eventually diagnostics, for autoimmune diseases such as multiple scle- rosis, systemic lupus, Crohn’s disease, and Alzheimer’s disease. Scientists are also re- searching applying the technology to immunotherapy for infectious diseases, such as ancer patients’ bodies c ontain A DIFFERENT CHIP: IsoPlexis uses microelectronics Lyme, and to vaccine development. immune cells that, through suc- fabrication techniques and software analytics to Michael Andreeff, M.D., a genetics profes- C simultaneously study thousands of immune cells. cessful immunotherapy, can sor at the University of Texas MD Anderson deliver proteins to destroy tumors. But it had cause he had seen the impact that early-stage Cancer Center and a pioneer in flow been difficult in the past to identify which im- life sciences firms could have on people’s lives. cytometry—the measurement of single-cell mune cells were the most powerful. The timing of the company’s found- characteristics—called the IsoPlexis “a very Now, IsoPlexis, a life sciences startup ing coincided with a boom in the use of elegant system.” He added that he was able based in Connecticut, has created “micro- immuno-oncology treatment. IsoPlexis re- to uncover some surprising results using the chips” that quickly identify 42 proteins emitted ceived early funding from Spring Mountain technology in his lab: “Importantly, the IsoPlexis from thousands of individual cells. Software Capital, Connecticut Innovations, Yale, the system may be able to predict what patients then analyzes the results to determine which National Institutes of Health’s Small Busi- will respond to immune-checkpoint inhibitors.” cells are the highly potent “Superman” cells ness Innovation Research grant, and venture While the process is not revolutionary, that are the most effective in immunotherapy. capital investors. Andreeff said that if these results are con- In biology, “to understand the complete Still, the startup had to convince its po- firmed, the IsoPlexis could be a 9+ on a picture, you have to look at thousands of tential customers that it offered benefits 10-point scale as a research tool. “No other cells,” says Rong Fan, IsoPlexis cofounder. over existing technology. “We never thought technology has provided this kind of predic- Fan developed the underlying science our goal would be to dethrone existing tech- tion,” he said. Asked whether he had a finan- while a postdoc at Caltech working with nology, but rather be a complement to them,” cial stake in IsoPlexis, Andreeff said, “I wish.” chemistry professor James R. Heath, who says cofounder and CEO Mackay. IsoPlexis’s —THERESA SULLIVAN BARGER is also director of the National Cancer Insti- microchips use microelectronics fabrication tute’s NSB Cancer Center. technology to trap single cells in a micro- Founded: 2013 Headquarters: Branford, When Fan, associate professor of biomedi- chamber and isolate them from one another, Conn. Founders: Rong Fan, Sean M ackay, cal engineering at Yale, came to New Haven, says Heath, now director of IsoPlexis’s sci- James Heath Employees: 91 Capital he met Sean Mackay, who was finishing up entific advisory board. One of the company’s raised to date: US $19 million, Series A & B his MBA. Mackay says he was looking to part- major inventions is the technique to parallel- POST YOUR COMMENTS at https://spectrum.ieee.org/

ISOPLEXIS ner with someone working in life sciences be- ize and squeeze microsensor detection pads isoplexis0519

SPECTRUM.IEEE.ORG | MAY 2019 | 19 INTERNET OF EVERYTHING_BY STACEY HIGGINBOTHAM OPINION

I’ve learned, in covering IoT for seven years, that there are two crucial rules that form the foundation for any good legislation. The first is an understanding that good security is all about thinking about security in the first place. This may sound obvious, but if you’re buying infusion pumps for a Veterans Affairs Hospital, you’re probably focused on buying the best infusion pump, not on securing it against cyberthreats. But with the IoT, security must be part of the basic functionality, and so security pro- fessionals should be deeply involved in the design and procurement of devices. The second rule for good security legislation is that government agencies must understand that in a connected world, good security is an ongoing process, not something you can set and forget. That’s why it’s encouraging to see that the bill would require NIST to evalu- ate device security every five years and update the government’s standards. Sure, five years may be an eternity in the world of connected devices and technology IoT SECURITY GOES exploits, but it’s a start. I have no idea if the bill will even get out of committee, or how it will look if it does, TO WASHINGTON but as it stands, I’d add a few more elements that could help round it out. First, IN 2016, attacks such as the Mirai botnet took down several popular I’d love for NIST to have a budget secured websites, and in doing so, brought attention to the need for security for creating the list of vulnerabilities and for Internet of Things (IoT) devices. Since then, the U.S. Congress has security elements, and then for managing made attempts to pass legislation around IoT security, including a vulnerability disclosures going forward. lame attempt in 2017, when senators introduced a bill that would prevent the gov- I’d also like to see some remediation ernment from buying connected devices that had one of a small number of glar- plan for all of the currently insecure ing security flaws. Once again, Congress is trying to pass legislation, but this time devices the government has under its around, there’s more to like in the bill. • The Internet of Things Cybersecurity purview. The government uses comput- Improvement Act of 2019 isn’t trying to dictate specifically how to secure connected erized and connected devices in a huge devices, as the 2017 bill did. Instead, it aims to build a framework that the govern- number of places, including weaponry ment can use to establish a list of characteristics required for secure connected systems for missile interception and devices. Promisingly, the bill allocates the task of figuring out the requirements for wildlife tracking in national parks. Obvi- a secure device to the technologically savvy National Institute of Standards and ously, a lack of security is more unnerv- Technology (NIST). Then it’s up to the Office of Management and Budget (OMB) to ing when missiles, rather than caribou, direct federal agencies how they should adopt the NIST guidelines. • Some secu- are involved, but the government should rity experts worry that this two-step approach will lead to lower security stan- be thinking about how to secure what’s dards for agencies, because even if NIST produces strong standards, OMB could out there, not just what it buys after a tell some or all agencies to ignore parts or even all of the standards. But that isn’t cybersecurity bill takes effect. n necessarily a bad thing: The National Park Service probably doesn’t require the ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/ same security guidelines that the Department of Defense requires. iotsecurity0519

20 | MAY 2019 | SPECTRUM.IEEE.ORG ILLUSTRATION BY Jude Buffum NUMBERS DON’T LIE_BY VACLAV SMIL OPINION

There may be no specific genetically programmed limit to life-span—much as there is no genetic program that limits us to a specific running speed. But life- span is a bodily characteristic that arises from the interaction of genes with the environment. Genes may themselves introduce biophysical limits, and so can environmental effects, such as smoking. The world record life-span is the 122 years claimed for Jeanne Calment, a Frenchwoman who died in 1997. Strangely, after more than two decades, she still remains the oldest survivor ever, and by a substantial margin. (Indeed, the margin is so big as to be suspicious: Her age and even her identity are in question.) The second oldest super centenarian died at 119, in 1999, and since that time there have been no sur- vivors beyond the 117th year. And if you think that you have a high chance to make it to 100 because some LIFE-SPAN AND of your ancestors lived that long, you should know that the estimated heritability of life-span is modest, just between LIFE EXPECTANCY 15 and 30 percent. Given that people tend to marry others like themselves, a phe- RAY KURZWEIL, GOOGLE’S CHIEF FUTURIST, says that if you can nomenon known as assortative mating, just hang on until 2029, medical advances will start to “add one addi- the true heritability of human longevity tional year, every year, to your life expectancy. By that I don’t mean is probably even lower than that. life expectancy based on your birth date but rather your remaining Of course, as with all complex mat- life expectancy.” Curious readers can calculate what this trend would do to the ters, there is always room for different growth of the global population, but I will limit myself here to a brief review of sur- interpretation of published statistical vival realities. • In 1850, the combined life expectancies of men and women stood analyses. Kurzweil hopes that dietary at around 40 years in the United States, Canada, Japan and much of Europe. Since interventions and other tricks will then the values have followed an impressive, almost perfectly linear increase that extend his own life until such time as nearly doubled them, to almost 80 years. Women live longer in all societies, with the major scientific advances can preserve current maximum at just above 87 years in Japan. • The trend may well continue him forever. It is true that there are for a few decades, given that life expectancies of elderly people in affluent coun- ideas on how such preservation might tries rose almost linearly from 1950 to 2000 at a combined rate of about 34 days per be achieved, among them the rejuvena- year. But absent fundamental discoveries that change the way we age, this trend tion of human cells by extending their to longer life must weaken and finally end. The long-term trajectory of Japanese telomeres, the nucleotide sequences female life expectancies—from 81.91 years in 1990 to 87.26 years in 2017—fits a sym- at the ends of a chromosome that fray metrical logistic curve that is already close to its asymptote of about 90 years. The with age. If it works, maybe it can lift the trajectories for other affluent countries also show the approaching ceiling. Records realistic maximum well above 125 years. available show two distinct periods of rising longevity: Faster linear gains (about But in 2019 the best advice I can give to 20 years in half a century) prevailed until 1950, followed by slower gains. • If we all but a few remarkably precocious read- are still far from the limit to the human life-span, then the largest survival gains ers of these essays is to plan ahead—but should be recorded among the oldest people. This was indeed the case for studies not as far ahead as the 22nd century. n conducted in France, Japan, the United States, and the United Kingdom from the ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/ 1970s to the early 1990s. Since then, however, the gains have leveled off. lifeexpectancy0519

ILLUSTRATION BY Kotryna Zukauskaite SPECTRUM.IEEE.ORG | MAY 2019 | 21 REFLECTIONS_BY ROBERT W. LUCKY OPINION

But maybe there could be some mech- anism that would take fuzziness as an input and hand off well-defined output to a computational unit. This unit could then bring to bear the kind of techniques we’ve used to master games. In real life we have such mechanisms. Consider American football, for example. There are rules about what happens following a forward pass that depend on whether it is caught or not caught. But “catch” is a fuzzy concept. So we have a device that digitizes the analog “catch.” It is called a referee. In law we have the equivalent in the courts, where judges and juries use various subjective standards such as “reasonableness” to determine whether or not an action falls on one side of the law or the other. And if we don’t like the court’s digitization, we treat it as an analog result and send it through another court. As a manager, I was the digital arbi- AI’s ACHILLES’ HEEL: ter on many personnel decisions—who got raises and in what dollar amounts, who got promoted, who got fired, and AMBIGUITY so forth. People always asked me what criteria I used for these decisions. MANY YEARS AGO, I was touring a working orchard with What is the algorithm you use? they a friend. His son, who was the orchard’s manager, was wanted to know. In truth, I wanted describing his work. His father and I, being engineers, got an algorithm too. There was a lot of into a discussion about how a robot might be instructed fuzziness involved. to pick the fruit. • The son stopped and stared at us in consterna- Besides being fuzzy, much of life tion. “What are you guys talking about!? It’s simple—you see it, you is influenced by luck. The best team pick it.” • Not so simple: It’s only now, decades later, that commercial doesn’t always win, and the best per- fruit-picking robots are on the radar. There are many everyday tasks son doesn’t always get the promotion. that seem trivial yet are difficult to describe and structure for automa- Life isn’t always fair, but this does shake tion. Humans have the advantage of common-sense reasoning, which is up the pieces, so I’m not sure if this is much more deep and profound than most people would believe. • In my a bug or a feature. Many board games, February column, I wrote about our success in creating computer pro- like Monopoly, do combine luck with grams that can master games like chess and poker. By their descriptions, skill. Maybe the fuzziness converter these games are extraordinarily simple—a small number of immutable could add a bit of randomness. rules involving a few elements, whether they be chess pieces or play- But I’m just dreaming about this. ing cards. But there is a paradox, because underneath this simplicity Whatever real-life task we’re trying to is an enormous complexity. Nonetheless, that complexity is precisely automate, someone will ask why it’s defined, and that’s what we engineers are good at.• However, life is taking so long. It’s simple, they’ll say. fuzzy and often ill defined. (If only real-life tasks could be modeled as But it really isn’t. n board games, we’d be in business.) I love the idea of fuzzy logic, but on ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/

reflection, I actually do want my computer to be precise. reflections0519

22 | MAY 2019 | SPECTRUM.IEEE.ORG ILLUSTRATION BY Dan Page

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www.nro.gov/About-the-NRO/Business-Opportunities ZIPLINE’S MEDICAL DELIVERY DRONES ARE CHANGING THE GAME IN RWANDA The Blood

rwanda is known as the land of a thousand hills, and our car seems to go over every one of them as we drive from the small town R of Muhanga to the even smaller town of Kinazi. The 50-kilometer trip into western Rwanda will take us well over an hour. We’re on our way to rendezvous with a blood-carrying drone that will make the trip in under 14 minutes. • The drone is operated by Zipline, a California-based company focused on delivering medical supplies in areas with poor infrastructure. And not long after we arrive at Kinazi’s hospital, the fixed-wing drone materializes out of the blue. In a blink-and-you’ll-miss-it moment, the drone descends, opens a set of doors in its belly, and drops a small package that parachutes to the ground. The drone immediately begins to climb and vanishes over the hills as a staff member crosses the hospital parking lot to pick up the package—a shipment of blood ordered by WhatsApp less than half an hour earlier. • We then climb back into our car to start our bone-jarring return drive to Muhanga, one of Zipline’s launch sites, winding our way over dirt roads. By the time we make it back, the drone is flying smoothly toward another hospital elsewhere in Rwanda, with a fresh package of blood in its belly.

24 | MAY 2019 | SPECTRUM.IEEE.ORG Is Here by EVAN ACKERMAN & MICHAEL KOZIOL

SPECIAL DELIVERY: Blood arrives by drone and parachute at medical facilities across Rwanda, cutting delivery times from hours to minutes. Delivery by drone is a futuristic idea that has caught the public’s imagination, and there are plenty of attempts to turn it into a commercial reality. Amazon, Google, and Domino’s Pizza have all pulled off carefully controlled demonstrations and pilot projects, delivering items such as sunscreen, burritos, and (of course) pizza to backyards and fields. But the world is waiting to see 1 whether any company can find a business model that makes drone delivery a sustain- able and profitable endeavor. The answer may be here in Rwanda, where Zipline is delivering blood to 25 hospitals and clinics across the country every day. Zipline is betting that transporting lifesaving medical supplies, which are often lightweight and urgently needed, will be the killer app for delivery drones. 2 We visited Zipline’s Rwanda operations to understand the technical challenges of building a drone-based delivery service. We found obsessively engineered drones that the company has optimized for blood BLOOD ON DEMAND: delivery, along with a detailed plan for inte- Several days’ worth of blood are stored grating them into the country’s medical sys- in Zipline’s fulfillment tem. Zipline’s methods could be a model for center. When an order Africa, as the company’s founders expand comes in, the blood is packed into a padded their drone services into other countries 3 cardboard box with a on the continent this year. But despite the parachute attached. company’s technological and logistical suc- cesses thus far, Zipline still has to prove that it can scale up its operations—that it can go big enough to match its soaring ambitions.

Rwanda has modern- ized rapidly since the 1990s, R when the country began its recovery from civil war and genocide. The change has been remarkable: Since 2000, the percent- age of the population living below the pov- erty line has dropped from 59 to 39 percent, and life expectancy has increased by nearly 20 years. The government’s Vision 2020 national development plan emphasizes technology infrastructure, and fiber-optic cables now run alongside main roads. More than 95 percent of the population is covered by 4G cellular networks. The government has also invested heav- ily in health care. But its push to construct hospitals and clinics has resulted in some shiny new medical facilities opening their doors to patients before the roads leading to them have been improved. Traffic is slow on

26 | MAY 2019 | SPECTRUM.IEEE.ORG PREVIOUS PAGES, JASON FLORIO/ZIPLINE; THESE PAGES: EVAN ACKERMAN (7) the two-lane highways that twist around the hills, while the roads that branch off toward small towns soon turn into dirt. For hospitals in need of critical medical supplies, Rwanda’s roads pose a real problem. Hospital administrators worry most about blood and blood products, which have a short shelf life and strict storage requirements. It’s also difficult to predict how many packs of each blood type will be needed at a given facility, and when. In an emergency, it can take up to 5 hours for a Rwandan hospital to receive a blood delivery via road, which could easily mean death for a patient in need. Three entrepreneurs—William Hetzler, Keller Rinaudo, and Keenan Wyrobeck— founded Zipline in 2014 with the goal of solving such problems through on-demand deliveries by drone. Rwanda was the ideal test bed, with its challenging terrain, relatively small size (about the same area as the U.S. state of Maryland), extensive wireless connectivity, and receptive government. Outside observers are cautiously opti- mistic about the company’s efforts so far. “I like Zipline’s approach in Rwanda—they’re operating commercially, which is more than most drone delivery companies [are doing],” says Adam Klaptocz, cofounder and CEO of Rigitech, a Swiss startup that’s using small cargo drones to connect rural communities in the developing world. “They’re not trying to be the solution for all drone deliveries,” says Klaptocz. “But they’re doing this, and it seems like they’re doing it better than the existing way.”

Zipline has two fulfillment centers in Rwanda, Z which it refers to as “nests.” The Muhanga nest, which we visited, is about 50 km from the capital of Kigali, and a 2-hour drive, thanks to lumbering trucks that clog the main roads. Its small cluster of buildings abuts a maize field, and the locals who work the field grudgingly move out of the way

TAKING OFF: whenever a drone passes low overhead. Technicians stow the Several times a week, blood and blood blood in the drone’s cargo products arrive here by truck. When one bay and run through preflight checks to prep shipment arrives during our visit, Israel the aircraft for launch. Bimpe, Zipline’s head of national imple- A 13-meter-long electric mentation, turns to us with a smile, say- catapult launches the drone into the sky at ing: “The blood is here!” Workers spring 100 kilometers per hour. into action, transferring the packs of whole

SPECTRUM.IEEE.ORG | MAY 2019 | 27 blood, plasma, and platelets into refrigerators. When an order comes in from a hospital via phone, website, WhatsApp, or SMS, a worker wraps the needed packs in padding and stuffs the bundle into a bright red box, which has a wax-paper parachute attached. A technician places the box and parachute in the belly of a drone behind a spring-loaded hatch, then snaps a modular battery pack into the drone’s nose. Two people carry the drone to a 13-meter-long electric catapult powered by a bank of supercapacitors, then run through a preflight checklist with the aid of a smartphone app. Zipline confirms FLYING HIGH: The drone travels the drone’s flight plan with the Rwanda Civil along a predetermined flight path to its destination. Once at the hospital Aviation Authority and requests flight clear- site, it drops its cargo by parachute for ance, while the company’s technicians do hospital staff to retrieve. their best to convince enthusiastic local kids to move a safe distance away from the launch. Finally, with a satisfying zzzing, the catapult flings the drone skyward, accelerating it to 100 kilometers per hour in half a second. It swiftly rises over the R wandan countryside to a cruising altitude of 120 meters. It’s a dramatic moment—and at Muhanga it happens 20 to 30 times a day. As soon as a drone—which the company calls a Zip—leaves the catapult, it’s fully autonomous. While both Zipline and the Rwanda Civil Aviation Authority track the aircraft and can redirect it at any time, in practice the Zips are mostly forgotten about until they return home, mission complete.

In the air, each Zip follows a predetermined MISSION COMPLETE: flight plan, relaying data on its position and The returning drone status through Rwanda’s wireless network. is caught in the air by a capture wire that Our visit to the Kinazi hospital, one of the snags its tail hook. Then closer delivery sites, shows us the other end technicians remove the of a Zip’s journey. About 5 minutes before battery pack and wings before carrying the the drone arrives, hospital staff members chassis away. get an automatic text alert telling them to send someone outside to await the delivery. At Kinazi, that means waiting at the edge of a small grassy field adjacent to the hospital’s parking lot. During our visit, the staff member arrives only after the drone has dropped its package, which just goes to show that blood delivery by drone isn’t the least bit exciting in Rwanda anymore. Zips can carry relatively large payloads long distances because they’re fixed-wing aircraft, which are significantly more aero- dynamically efficient than rotorcraft (such as today’s common quadcopters). Launching a fixed-wing drone from a catapult is easy, but landing it safely—without landing gear or

28 | MAY 2019 | SPECTRUM.IEEE.ORG EVAN ACKERMAN (11) a lengthy runway—is a challenge. Zipline’s solution is a recovery system that the team affectionately refers to as Tall Bob. Its two 10-meter-high towers each have a vertically mounted rotating arm, and a cable is strung between the arms. As a returning Zip flies between these two towers, the arms rotate upward, in a fraction of a second, to snag the cable on a tiny metal hook below the Zip’s tail. The drone is pulled to a stop within a few meters, then the arms allow the drone to swing down and back between the towers. In principle, it’s similar to the way planes land on aircraft carriers. To reset the system, workers simply lift the Zip off the wire at ground level, and then rotate the arms back up to prepare for the next capture. The Zipline team has grown accustomed to the remarkable precision of its drone-capturing system, but during our visit we never get tired of seeing the wire pluck Zips out of the sky. While Zips can’t launch when crosswinds are too intense, they can handle both high winds and rain once they’re airborne, so weather-related delays at the launch site tend to be brief. But the system isn’t flawless: Zips will turn around if strong head winds drain too much of their battery power, and despite dual motors and redundant ailerons for flight control, mechanical failures do sometimes happen. If the Zip can’t make it back to the nest, it can autonomously deploy a parachute to bring itself gently to the ground. Zipline estimates that the emergency parachute deploys in around one in a thousand flights.

With dozens of orders coming in every day, Zipline W needs to be sure that it always has drones ready to fly. So its engineers designed the Zips to be as modular as possible, allowing technicians to easily detach different pieces for repairs. While such repairs are common, particularly on the strain-bearing wings, there are always more than enough components to snap together into a fully assembled drone. A bank of chargers ensures that a charged battery pack is always

READY, SET, GO: A bank of battery ready to be slotted into a drone being chargers and a rack of wings ensure prepped for launch. there are always components on hand The Zipline facility in Muhanga takes, on to assemble into a complete drone. Technicians can track each drone’s average, 10 minutes to launch an order. But flight on an iPad. Zipline’s engineers think that’s 9 minutes too

SPECTRUM.IEEE.ORG | MAY 2019 | 29 long. Bimpe says that incremental changes Because weight determines how long Zipline’s next-generation battery, cur- to the process will eventually enable them and how far a drone can fly, Zipline’s rently in development, will be much eas- to fulfill an order in less than 60 seconds. engineers are always looking for ways ier to assemble, with cells that slip into “We just need to improve it a bit more,” to lighten the load. Much of the focus prefabricated plates and get spot-welded he says. “It’s tweaking operational proce- is on the battery, which is the heaviest into place. Yet the company can’t seem dures and improving software to reduce component of the aircraft. “We fight to stop reexamining, reconsidering, and that time to 1 minute. We receive an order super, super hard to shave off grams,” refining its designs. “Watt-hours per kilo,” and as soon as we finish packing, we just says Michael Newhouse, Zipline’s battery says Newhouse, referring to the essen- put it on the Zip and it’s ready to go.” lead. The Zipline team uses the smallest- tial metric driving the company’s battery Expected improvements in the Zips gauge wires they can get away with and design process. “That’s what’s going to themselves will boost range: Today, the special wire strippers to remove excess make or break your system.” farthest hospital that Zipline delivers insulation, thus saving fractions of grams. Despite the intense focus on keeping to is Butaro District Hospital, about The current Zipline battery is a com- the drone’s weight down, today’s Zips 80 km away (45 minutes as the Zip flies). bination of precision engineering and can carry a payload of only 1.3 kilograms. handmade charm. To make one battery, “Right now, with this generation, we can a technician puts 144 separate lithium- deliver two units of blood,” with some ion cells—each only slightly larger than capacity to spare, says Eric Watson, a an AA battery—into slots in the battery systems engineer at Zipline. The remod- The Zippy Flier case, epoxies them by hand, and wires eled Zip that the company is currently Zipline’s drones are modular. When an order them together. “It feels halfway between working on will have a lighter chassis, a comes in, technicians snap together the three main components: the lightweight hobby construction and an assembly more efficient battery, and a payload of foam chassis [1], the wings [2], and the line,” says Newhouse. The batteries were 1.75 kg, enabling a single drone to carry battery unit [3], which also contains the first assembled on-site in Rwanda, but are up to three units of blood at a time. It will flight plan. Scanning QR codes [4] initiates automatic preflight tests of the drone’s now shipping straight from California. also have a receiver for transponder sig- systems. To keep the drone flying in the event of a minor mechanical failure, it has two motors [5] and redundant ailerons [6] on the wings that help maintain flight control. The drone’s cargo compartment [7] contains the package of blood until 2 it’s parachuted down to the delivery site. To obviate the need for a lengthy runway for takeoffs and landings, an electric catapult 6 launches the drone, and a wire strung 3 between towers captures the returning drone by snagging a 3-centimeter metal hook [8] on the drone’s tail.

4 1

30 | MAY 2019 | SPECTRUM.IEEE.ORG ILLUSTRATION BY Chris Philpot nals from other aircraft, a backup communication system that uses a satellite link, and onboard sense-and-avoid equipment that will, Watson says, “be able to detect and avoid uncooperative aircraft in our airspace.” This advanced feature will likely become a safety-critical sys- KAYONZA tem for delivery drones as the skies get KIGALI more crowded. MUHANGA

While the technology involved in drone W delivery is impressive, the economics are more uncertain. Experts say Zipline’s high-tech solution for blood delivery is a new twist on an old story. “Go to any hospital in Africa and you’ll find a graveyard of machines,” says COVERING A COUNTRY: Zipline’s drones can fly to hospitals up to 80 kilometers away along Jonathan Ledgard, who was the predetermined routes, allowing two distribution sites to cover nearly all of Rwanda. Afrotech director at the École Polytech- nique Fédérale de Lausanne, in Switzerland, until 2016. “The whole and 150 deliveries per day. The Ghanaian As of press time, Zipline’s drones history of Africa is medical equipment government estimates a per-delivery cost have flown a total of over 1 million km. that was too expensive.” of $17. Both the minority party in the As Zipline scales up its operations, it will Ledgard notes that Zipline currently country’s parliament and the Ghana likely clock its next million kilometers receives subsidies from the Rwandan gov- Health Service criticized the contract as in under six months. In addition to its ernment to make its service affordable for being too expensive, arguing that funds expansion into Ghana, Zipline is also hospitals. He suggests the company may could be better spent elsewhere. Never- part of a pilot program run by the U.S. be in trouble if those subsidies end. “The theless, the contract was approved, and Federal Aviation Administration, which price points they have to charge once the Zipline has already begun making deliv- will test medical deliveries in rural areas subsidies end are far, far, far too high eries from its first distribution center in of North Carolina later this year. for developing countries,” Ledgard says. the country. The Rwandan government recently Zipline is reluctant to disclose how Over the long term, Zipline argues that awarded Zipline a new, three-year con- much its Rwandan fulfillment centers minimizing waste in the medical system tract, which includes provisions for deliv- cost to operate or how much it gets paid will help the drones pay for themselves. ering other medical products beside blood, by the Rwandan government per delivery. In Rwanda, the cost to collect, test, and such as medicine and vaccines. That ser- The company does admit that routine store a unit of blood is about $80. Before vice expansion means that Zips will soon blood deliveries by drone are currently Zipline came along, about 7 percent of be making drops to many small clinics, not more expensive than routine deliveries blood packs expired without being used, only to hospitals. Zipline is also planning to by ground vehicle, which move more costing the Rwandan government more assemble its drones in Rwanda rather than blood per load. But Zipline argues that than $1 million annually. In 2018, the importing them from the United States. the economics change in emergencies. hospitals that Zipline serves wasted no Clearly, Zipline is in Rwanda to stay. As Zipline seeks to expand its delivery blood packs at all. It’s getting dark at Zipline’s Muhanga services to more African countries, cost Ledgard says Zipline may find a busi- nest as we pack our bags and get ready and sustainability are becoming central ness model that works—but only for for the long, winding drive back to topics of discussion. Its first expansion lifesaving medical deliveries. He says Kigali. Red landing lights turn on along effort, in Tanzania in 2018, fell through the current drones can’t compete with the approach path that the Zips follow— during contract negotiations with the motorbikes, which can carry about 15 kg, the drones don’t need the lights, but they government. But at the end of 2018, the for routine deliveries. “Until you get to look cool. In the distance, we can hear the government of Ghana approved a four- 6 or more likely 12 kg [for drones], it’s not faint buzz of another Zip returning home year contract to deliver blood and other viable,” Ledgard says. Yet he gives Zipline after making its delivery of blood. Any- medical supplies by drone, worth an esti- credit for getting a delivery-drone com- where else on Earth, it would be futur istic. mated US $12.5 million for Zipline. pany off the ground. “They’ve done what In rural Rwanda, it’s just routine. n The plan for Ghana calls for four fulfill- people like me have been talking about,” ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/

ZIPLINE ment centers that will make between 100 he says. “I take my hat off to them.” ziplinedrones0519

SPECTRUM.IEEE.ORG | MAY 2019 | 31 JOURNEY TO THE CENTER OF THE SOLAR SYSTEM How the Parker Solar Probe survives close encounters with the sun

By Andrew Driesman, Jack Ercol, Edward Gaddy & Andrew Gerger

SPECTRUM.IEEE.ORG | MAY 2019 | 33 OVER THE PAST SIX DECADES, 12 PEOPLE HAVE WALKED ON THE MOON, SPACECRAFT HAVE VISITED EVERY PLANET FROM MERCURY TO NEPTUNE, AND FOUR ROVERS HAVE RACKED UP MORE THAN 60 KILOMETERS TRAVELING ON THE SURFACE OF MARS. AND YET, DESPITE THE BILLIONS OF DOLLARS SPENT ON THE WORLD’S CIVILIAN SPACE PROGRAMS, NEVER HAS A PROBE JOURNEYED VERY CLOSE TO THE SUN. THE NEAREST APPROACH, BY THE HELIOS B PROBE IN 1976, CAME NO CLOSER THAN 43 MILLION KM.

Why is that? There’s been no lack of interest in the sun— space age has been the ability of a probe to endure the quite the opposite. Of all extraterrestrial bodies, the sun hellishly hostile near-sun environment. But this obstacle has the largest influence on us: It controls the radiation has recently given way to some new technologies, which doses that astronauts experience and also affects the elec- we and others at the Johns Hopkins University Applied tronics in the myriad satellites on which we increasingly Physics Laboratory have built into a spacecraft called the rely. Solar storms can even disrupt electric power grids, as Parker Solar Probe. That probe (named after astrophysi- famously happened in 1989, when one such storm blacked cist Eugene Parker) was launched last August and has just out the entire province of Quebec and caused ripple effects recently completed its second close pass by the sun. on electric grids in the United States. At the probe’s closest approach, about 6 million km from So there’s no shortage of practical reasons to study the sun. the sun’s surface, solar irradiance is almost 500 times as much And it still holds many deep scientific mysteries. Unlike other as it is at Earth’s orbital distance—a whopping 650 kilowatts bodies in the solar system, the atmosphere high above it is per square meter. Along with that immense intensity come more than two orders of magnitude hotter than it is at the extreme ultraviolet rays, which degrade materials rapidly. surface. What causes that phenomenon, known as coronal But ultraviolet radiation is not the only challenge. Sun-grazing heating? And what mechanisms create the solar wind, accel- comets are torn apart by the sun’s intense gravity, leaving erating parts of the sun’s atmosphere to velocities ranging the near-sun environment filled with dust that speeds along from 300 to 700 kilometers per second? These questions, at upwards of 300 km/s, an order of magnitude faster than among others, have baffled scientists for decades. such particles travel in the vicinity of Earth. Indeed, the case for studying the sun has never been For the Parker Solar Probe to complete its mission, the hard to make. The limiting factor since the dawn of the spacecraft will need to survive this barrage of dust and

34 | MAY 2019 | SPECTRUM.IEEE.ORG ED WHITMAN/JOHNS HOPKINS APL/NASA wanted, but this compromise simplified the construction construction the simplified compromise but this wanted, had scientists some as sun to the close won’t as quite get rials needed to construct an adequate heat shield would would shield heat adequate an to construct needed rials until not exist did feat simply that to accomplish required making while years seven for at least radiation intense mission’s success, the technology behind it has been well well been ithas behind technology the mission’s success, the rest of the spacecraft. Before that, the refractory mate refractory the that, Before spacecraft. of the rest the - suffi and lightweight was that shield aheat to fabricate possible became it point that At available. became foams carbon-composite high-temperature when 1990s, late the tiple close passes, rather than just one or two. just than rather passes, close tiple of design the And onspacecraft. for use materials these have been too heavy to fly. heavy too have been before NASA settled on the current strategy. The probe strategy. current onthe settled NASA before a mission to the sun went through a decade of revisions of revisions adecade went through sun to the a mission ciently stiff, one that could provide the needed shade for shade the needed provide could that one stiff, ciently of the spacecraft and allows it to study the sun during mul during sun the itto study allows and spacecraft of the scientific measurements autonomously. The technologies autonomously. The technologies measurements scientific Although the heat shield is absolutely critical to the critical absolutely is shield heat the Although It took some years for the Parker probe team to adapt to adapt team probe Parker for the years some It took solar cells will bemounted, stretched outasit will be while the spacecraft is far from the sun. here undergoing thermal testing. In the foreground [lower right] isarectangular surface on which A DRESS REHEARSAL: - - The solar array cooling system for the Parker Solar Probe spacecraft isshown The Apollo command module used fuel cells. But more But cells. fuel used module command The Apollo much heat as a satellite circling Earth experiences, so the the so experiences, Earth circling a satellite as heat much it had panels solar power-generating spacecraft’s the ing isotope thermoelectric generators to produce electricity. electricity. produce to generators thermoelectric isotope radio use system solar of the reaches far to the sent probes typically, electrical power comes from photovoltaic panels. photovoltaic from comes power electrical typically, found on no other spacecraft, meaning that to design and and to design that meaning spacecraft, onno other found is system cooling This cool. it to keep used system the boldly go where no one had gone before. gone had one no where go boldly to, had well, team engineering Hopkins Johns our it build as many as 13 watts of heating in the panels for every watt watt for every panels the in of heating watts 13 as many as of electrical power generated. This is almost 500 times as as times 500 almost is This generated. power of electrical manage out how to to figure had team easy. Not so. Our design engineers the think you might sun, to the close opment of the probe’s equally important solar array and and array solar important probe’s ofopment the equally devel the describe instead we already, here covered will so standard method of cooling panels passively doesn’t apply. passively panels of cooling method standard every Because the Parker Solar Probe would be operating operating be would Probe Solar Parker the Because

spacecraft needs a source of electrical power. Some of electrical asource needs SPECTRUM.IEEE.ORG

MAY 2019

35 - - - Accumulator Solar panel, primary section Secondary section

Radiator

Heat shield

PARKER PROBE’S PLUMBING: Various components work together to Early on, we decided to mount the secondary sections keep the solar panels from getting too hot when the probe nears the so that they would be a few degrees closer to facing the sun. That’s done in large measure by rotating the panels back so that only the secondary sections of each panel are exposed to the sun’s sun than the primary sections are. Our objective was rays. Water pumped through the probe’s active cooling system carries to ensure that the angle of the sunlight striking the sur- heat from the two panels to radiators kept in the shadow of the shield. face was never less than 10 degrees. If this angle were to become any more acute, small variations in that angle would cause large changes in power output, which could The probe’s solar array consists of two wings. Each is be difficult to control. about two-thirds of a meter wide and a little more than a We modeled performance very carefully as we were meter long. The wings house solar cells that were designed designing this solar array. That modeling was especially to work well at high irradiance levels. But sufficient elec- tricky for this mission because we couldn’t just treat the trical output was not the issue—the challenge was keep- sun as a distant point source of radiation: We had to take ing them cool. into account that when the probe approached the sun, the In large part, that’s done by controlling the geometry of partial shading from the heat shield would cause the solar the probe’s solar panels. As the spacecraft nears the sun, the cells to receive only rays coming from the outer fringes of wings with these panels are rotated back toward the body the solar disk, what astronomers call the limb. of the spacecraft so that the sun’s rays impinge on them at a The limb is redder and dimmer than the sun as a whole. shallow angle. This decreases the amount of sunlight falling That’s because the sunlight coming from the limb has to on the panels and puts more of the wings into the shadow or pass through more of the sun’s lower atmosphere, so the partial shadow of the 11-centimeter-thick heat shield mounted only light that escapes comes from higher up, where tem- on the sun-facing side of the spacecraft. peratures are lower. To be able to predict the electrical To make this strategy work better, we designed each output of the solar panels, we had to calculate how the wing to have two distinct sections. Most of the area of a color of the light falling on them would change with the wing, the primary section, serves as the source of power probe’s varying distances from the sun. most of the time. But when the spacecraft swoops close to the sun, the wings are angled so that their primary sec- our biggest worry while we were designing the probe’s tions are entirely in the shadow of the heat shield. Only photovoltaic array was not that it wouldn’t work correctly the small secondary sections at the tip of each wing are after launch, but rather that it would degrade over time

exposed to the sun’s rays. faster than expected. That’s what had happened to some INGALLS/NASA; BILL APL; HOPKINS JOHNS LEFT: FROM CLOCKWISE APL/NASA HOPKINS WHITMAN/JOHNS ED

36 | MAY 2019 | SPECTRUM.IEEE.ORG LIGHT THIS CANDLE: The United Launch Alliance Delta IV Heavy rocket launched the Parker Solar Probe from Cape Canaveral Air Force Station, Fla., on 12 August 2018 [top]. During launch, the probe was protected by a slender fairing, as can be seen in a photograph from a month earlier [bottom], taken while the fairing was being assembled at the Astrotech Space Operations facility in nearby Titusville.

previous space probes with trajectories that brought them close to the sun. For instance, the solar array of the MESSENGER mission to Mercury (which was also designed, built, and operated by the Johns Hopkins Applied Physics Lab) was predicted to degrade by 10 percent over the course of its 11-year mission. In fact, its output diminished by 50 percent, for reasons nobody could quite understand. MESSENGER was nevertheless successful because it stayed relatively close to the sun, where sunlight was intense enough for the craft to work properly even with an array that wasn’t performing as desired. This wouldn’t be the case, though, for the Parker Solar Probe. Its highly elliptical orbit periodically takes it outside the orbit of Venus. At those distances from the sun, it couldn’t func- tion if its solar panels started providing much less energy than expected. When the Parker probe was first conceived, we decided to design its solar array so it would still be able to do the job even if it suffered as much as MESSENGER’s did. But as the probe’s design matured, we and others at the Applied Physics Lab decided to take a different tack. We resolved to figure out what had caused the anomalous degradation of the solar panels on earlier spacecraft so that we could avoid whatever the problem was. Initially, we suspected that two issues might be at play. One possibility could be outgassing from the adhesives used in the construction of these panels. Such outgassing would, we reasoned, deposit a film of adhesive material on the top of the cells, which would then turn brown after exposure to ultraviolet light. All solar arrays outgas to some extent, but the effect is worsened by high heat and radiation. Another possibility was that the transparent adhesive used to attach the glass covers to the solar cells had turned brown, again because of exposure to ultraviolet light. Through extensive testing, we discovered that this process indeed accounted for most of the degradation. We soon figured out that we could reduce this darkening by driving out the more volatile components in the cover-glass adhesive. Doing so | CONTINUED ON PAGE 52

SPECTRUM.IEEE.ORG | MAY 2019 | 37 38 May 2019 spectrum. ieee.org

TECHNOLOGY TUCKED INSIDE YOUR EARS WILL AUGMENT YOUR DAILY LIFE + + + HeHere comea ther ables

he eyes, it’s been said, are windows to the soul. I’d argue that the real portals are the ears. ¶ Consider that, at this very moment, a cacophony of biological conversations is blasting through dime-size patches of skin just inside and outside BY POPPY the openings to your ear canals. There, blood is coursing through CRUM your veins, its pressure rising and falling as you react to stress and Illustrations excitement, its levels of oxygen changing in response to the air by Anders around you and the way your body is using the air you breathe. Here we can also detect the electrical signals that zip through Wenngren the cortex as it responds to the sensory information around us. And in that patch of skin itself, changing electrical conductivity signals moments of anticipation and emotional intensity. The ear is like a biological equivalent of a USB port. It is unpar- alleled not only as a point for “writing” to the brain, as happens when our earbuds transmit the sounds of our favorite music, but also for “reading” from the brain. Soon, wearable devices that tuck into our ears—I call them hearables—will monitor our biological signals to reveal when we are emotionally stressed and when our brains are being overtaxed. When we are struggling to hear or understand, these gadgets will proactively help us focus on the sounds we want to hear. They’ll also reduce the sounds that cause us stress, and even connect to other devices around us, like thermostats and lighting controls, to let us feel T more at ease in our surroundings. They will be a technology that VEMENT OVEMENT E STIMUL O M S RV A WHAT CAN BE M E E TI Y N O E S N U ACCESSED G

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SICAL H HY EA P LT H WHAT THEY TELL A HEARABLE ABOUT YOU is truly empathetic—a goal I Scenario: Superhearing have been working toward as You’re trying to have a conversation with friends at a loud, crowded restaurant. chief scientist at Dolby Labo- ratories and an adjunct professor at Stanford University.

How will future generations of hearables make life better? I’ve envisioned many scenarios, but here are four to get things started. Scenario 1: Say you’re trying to follow a basketball game Your hearables track your brain waves on TV while cooking in your 1 and determine that you‘re struggling to hear your friends. The devices adjust the kitchen. You’re having trouble signal-to-noise ratio and the direction of following the action, and your their microphones to make it easier for you hearables know there’s a prob- to understand the people nearby. lem because they’ve detected an increase in your mental stress, based on changes The hearables in your blood pressure and 2 can help even more, because brain waves. They can figure the devices can out exactly where you’re try- distinguish your ing to direct your attention by friends from everyone else based on pairing that stress increase previously collected with variations in the electri- audio fingerprints of cal signals created in your ear their voices. as you move your eyes. Then the hearables will automatically increase the volume of sounds coming from that direction. That’s a pretty simple fix ing noisy unrest from children in the back seat, as well as the that could make you a little more relaxed when you finally get mental stress it’s putting on you. The devices increase the to the dinner table. smartphone volume while also instructing the car to adjust Scenario 2: You find yourself at a popular new restaurant, seat temperature and airflow—inspired by previously tracked where loud music and reverberant acoustics make it difficult to biometrics—and perhaps start softly playing your favorite music. hold conversations (even if you don’t have hearing loss). Your They even understand your child’s “I need to go potty” as a hearables are monitoring your mental effort, again by track- bathroom request, analyze it to determine its urgency, and ing your brain waves, determining when you are struggling decide whether the navigation app should immediately search to hear. They then appropriately adjust the signal-to-noise for the closest rest stop, or look for one near a restaurant— ratio and directionality of their built-in mics to make it easier because they also heard your other daughter say she’s hungry. for you to understand what people nearby are saying. These Scenario 4: You’ve been wearing a hearable for a few years hearables can distinguish your friends from the patrons you now. Recently, the device has been detecting specific changes wish to ignore, based on audio fingerprints that the device in the spectral quality and patterns of sounds when you speak. previously collected. They can even figure outexactly whom After tracking this trend for several months, your hearable you are trying to hear by tracking your attention, even if you suggests that you schedule an appointment with your physi- can’t see the person directly. We’ve all been at a party where cian because these changes can correlate with heart disease. we heard our names in a conversation across the room and wanted to be able to teleport into the conversation. Soon we’ll Nothing in these scenarios is beyond what we’ll be able to be able to do just that. accomplish in the next five years. For all of them, the neces- Scenario 3: You’re driving your car, with your partner next sary hardware or software is available now or well on its way to you and your two children in the back seat. You’re tired in laboratories. from hours of driving and the children are getting noisy, which Start with the earpieces themselves. Wireless earbuds such makes it hard for you to pay attention to the directions coming as Apple’s AirPods, which partially occlude the ear canal, from your smartphone. And then your daughter announces and fully occlusive ones, such as Nuheara’s IQbuds or Bose’s she needs to go potty—now. Your hearables detect the increas- Sleepbuds, show how advances in miniaturization and battery

40 | MAY 2019 | SPECTRUM.IEEE.ORG technology have enabled small, lightweight form factors that monitors in the ear, where blood vessels and nerves run close weren’t possible just a decade ago. Nonetheless, small form to the surface, can give them a sensitivity advantage compared factors mean limits on battery size, and battery life is still a with their placement in wrist-worn or other types of wearables. make-or-break feature that will require innovation to power There are still quite a few challenges in getting the ergonom- a large number of sensors and machine-learning algorithms ics of hearables right. The main one is contact—that is, how for days at a time, without recharging. Some near-term solu- designers can ensure adequate continuous contact between tions will better optimize computation efficiency by distrib- an earbud and the skin of the outer ear canal. Such contact is uting processing among the hearable, a user’s mobile, and essential if the devices are going to do any kind of accurate bio- the cloud. But look out for some transformative innovation logical sensing. Natural behaviors like sneezing, chewing, or in energy storage over the next few years. A personal favorite yawning can briefly break contact or, at a minimum, change from the past year was Widex’s debut of a fuel cell for in-ear the impedance of the earbud-skin connection. That can give a devices capable of reaching a full day’s charge in seconds. hearable’s algorithms an incomplete or inaccurate assessment As for sensors, we already have ones that can monitor heart of the wearer’s mental or physical states. I don’t think this will be rate optically, as done today by many wearable fitness track- a huge obstacle. Ultimately, the solutions will depend as much ers, and others that can measure heart rate activity electrically, on insightful algorithms that take into account the variability as done today by the Apple Watch Series 4. We have sensors caused by movement as they do on hardware design. that monitor blood oxygenation, familiar to many from the finger-clip monitor used in doctors’ offices but already migrat- Speaking of software, the abilities of AI-based virtual assis- ing into fitness trackers. We have rings, watches, and patches tants have, of course, blossomed in recent years. Your smart that track physical and emotional stress by measuring galvanic speaker is much more useful than it was even six months ago. skin response; blood pressure monitors that look like brace- And by no means has its ability to understand your commands lets; headbands that track brain waves; and patches that moni- finished improving. In coming years, it will become adept at tor attention and drowsiness by tracking eye movement. All of anticipating your needs and wants, and this capability will these devices are steadily shrinking and getting more reliable transfer directly to hearables. every day, on a trajectory that will soon make them appropri- Today’s virtual assistants, such as Amazon’s Alexa and Apple’s ate for use in hearables. Indeed, positioning these kinds of Siri, rely on the cloud for the powerful processing needed to

Scenario: Personal stress assistance

You’re out driving with your family, and the children are The hearable 1 getting so noisy that it’s hard to understand the directions 4 understands coming from the navigation app on your smartphone. this as an urgent request and orders your smartphone’s navigation app to find a nearby restroom.

Your daughter The hearable senses the stress you’re feeling and takes steps to alleviate it. 3 announces 2 The device turns up the volume on the smartphone, adjusts the temperature that she needs a and airflow in the car, and perhaps starts softly playing your favorite music. bathroom—now.

SPECTRUM.IEEE.ORG | MAY 2019 | 41 respond to requests. But artificial neural network chips coming Within five years, a new wave of smart hearing aids will be soon from IBM, Mythic, and other companies will often allow able to recognize stress, both current and anticipatory. These such intensive processing to be carried out in a hearable itself, intelligent devices will do this by collecting and combining sev- eliminating the need for an Internet connection and allowing eral kinds of physiological data and then using deep-learning near-instantaneous reaction times. Occasionally the hearable tools to tune the analysis to individuals, getting better and bet- will have to resort to cloud processing because of the complex- ter at spotting and predicting rising stress levels. The data they ity of an algorithm. In these cases, fifth-generation (5G) cellular, use will most likely include pulse rate, gathered using optical which promises median speeds in the hundreds of megabits per or electrical sensors, given that a rising heart rate and shifts second and latencies in single-digit milliseconds, will potentially in heart rate variability are basic indicators of stress. reduce the latency to as little as tens of milliseconds. These hearables will likely also use miniature electrodes, These hearables won’t have to be as tiny as earbuds that placed on their surfaces, to sense the weak electric fields around fit fully inside the entrances to the ear canals. Today, some the brain—what we sometimes refer to as brain waves. Future people wear their Apple AirPods for several hours every day, hearables will use software to translate fluctuations in these and it wasn’t so long ago that Bluetooth earpieces for mak- fields at different frequencies into electroencephalograms ing voice calls were fashion accessories. (EEGs) with millisecond resolution. Decades of research In terms of form factor, designers are already starting have helped scientists draw insights into a person’s to move beyond the classic in-ear monitor. Bose state of mind from changes in EEGs. For exam- recently introduced Bose Frames, which have ple, devices often look for waves in the fre- directional speakers integrated into a sun- quency range between 7.5 and 14 hertz, glasses frame. Such a frame could house known as alpha waves (the exact bound- many hearable features in a design aries are debatable), to track stress and most of us are already comfortable relaxation. Fluctuations in the beta wearing for extended periods. Most waves—between approximately 14 and likely, designers will come up with 30 Hz—can indicate increased or other options as well. The point is reduced anxiety. And the interaction that with the right balance of form, between the alpha and beta ranges is battery life, and user benefits, an AI- a good overall marker of stress. powered hearable can become some- These hearables may also measure thing that some people will think nothing sweat, both its quantity and composi- about wearing for hours at a time, and per- tion. We all know we tend to sweat more haps most of the day. when we’re under stress. Sensors that measure variations in the conductance of our skin due to What might we expect from early offerings? Much of changes in our sweat glands—known as the galvanic skin the advanced research in hearables right now is focusing on response—are starting to show up in wrist wearables and will cognitive control of a hearing aid. The point is to distinguish be easily adapted to the ear. (You may be familiar with this where the sounds people are paying attention to are coming technology for its role in polygraph machines.) Microfluidic from—independently of the position of their heads or where devices that gather sweat from the skin can also help measure their eyes are focused—and determine whether their brains are the rate of sweating. And researchers recently demonstrated working unusually hard, most likely because they’re struggling that a sensor can detect cortisol—a steroid hormone released to hear someone. Today, hearing aids generally just amplify all when a person is under stress—in sweat. sounds, making them unpleasant for users in noisy environ- These hearables will combine this physiological picture of ments. The most expensive hearing aids today do have some user stress with the sounds picked up by their microphones smarts—some use machine learning along with GPS mapping in order to understand the context in which the user is oper- to determine which volume and noise reduction settings are ating. They will then automatically adjust their settings to the best for a certain location, applying those when the wearer environment and the situation, and amplify the sounds the enters that area. user most cares about while they screen out other sounds that This kind of device will be attractive to pretty much all of us, could interfere with comprehension. not just people struggling with some degree of hearing loss. The sounds and demands of our environments are constantly chang- A team from Columbia University, Hofstra University, and ing and introducing different types of competing noise, rever- the Neurological Institute recently took the idea of decod- berant acoustics, and attention distractors. A device that helps ing the electrical activity in the brain to help reduce stress a us create a “cone of silence” (remember the 1960s TV comedy step further, demonstrating the effectiveness of using brain- “Get Smart”?) or gives us superhuman hearing and the ability to wave detection with machine learning to help people cope direct our attention to any point in a room will transform how with multiple people talking simultaneously and devising an we interact with one another and our environments. algorithm that can reliably identify the person whom a lis-

42 | MAY 2019 | SPECTRUM.IEEE.ORG tener is most interested in hearing. The experiment involved have concerns—for example, that hearables could be hacked recording brain waves while a research subject listened to to eavesdrop on meetings. someone speaking. Then the researchers mixed the sounds But for a hearable to provide maximum value, it must spend of the target speaker with a random interfering speaker. as much time as possible monitoring its owner’s daily life. While the subject struggled to follow the story being narrated Otherwise, the machine-learning systems that support it won’t by the target speaker in the mix of sound, the researchers have the detailed history and constant fresh supply of infor- compared the current brain-wave signals with those of the mation that any AI device needs to keep improving. previous recording to identify the target of attention. Using There are also some thorny legal issues to consider. A couple an algorithm to separate the voices into separate channels, of years ago, prosecutors in Arkansas subpoenaed Amazon to the system was then able to amplify the voice of the target release information collected by an Echo device that was in a speaker. While the researchers used implanted electrodes to home where a murder occurred. Will people and businesses conduct this experiment, a version of this technology could shy away from using smart hearables because the data they migrate into a noninvasive brain-monitoring hearable that collect could one day be used against them? increases the volume of a target speaker’s voice and damp- Various strategies already exist to address such concerns. For ens other sounds. example, to protect the voiceprints that voice-based biomet- ric systems use for authentication, A HEARABLE THAT LISTENS TO ITS OWNER FOR WEEKS, MONTHS, some systems dice the audio data into chunks that are encrypted with OR YEARS WILL HAVE DEEP INSIGHT INTO THAT PERSON’S MIND. keys that change constantly. Using this technique, a breach involving Tomorrow’s hearables could also improve our physical as one chunk won’t give a hacker access to the rest of that user’s well as mental well-being. For example, a hearable could diag- audio data. The technique also ensures that a hacker won’t be nose and treat tinnitus, the so-called ringing in the ears often able to obtain enough audio data to create a virtual copy of the caused by the loss of sensory cells in the cochlea or damage user’s voice to fool a bank’s voice-authentication system. Addi- to neural cells along the route from the cochlea to the brain. tionally, developments in cryptography that allow algorithms To diagnose the problem, the hearable could play a sound to work with fully encrypted data without decrypting it will that the wearer adjusts to match the tone of the ringing. Then, most likely be important for the security of future hearables. to treat the condition, the hearable can take advantage of its Another, perhaps thornier, challenge involves mental health. proximity to a vagus nerve branch to train the brain to stop Because hearables can monitor our internal states, tomorrow’s the neural activity that caused the annoying ringing sound in hearables will learn things about us that we may not know— the first place. or even be prepared to know. Vagus nerve applications like this are in the early research For example, research by IBM found that an algorithm could phase, but they hold much promise for hearables. The vagus predict the likelihood of the onset of psychosis within five years nerves are among a dozen major cranial nerve pairs. They run and diagnose schizophrenia with up to 83 percent accuracy sim- from the brain to the stomach, one on each side of the body, ply by analyzing certain components of someone’s speech. But with branches that go through the skin near the nerve that car- what would a hearable—perhaps one bought simply to improve ries the sensory information from the inner ear to the brain. hearing in restaurants and keep an eye on the user’s blood pres- Doctors stimulate these nerves electrically to treat epilepsy and sure—do with that kind of information? A hearable that listens depression, and researchers are testing such stimulation for to its owner for weeks, months, or years will have deep insight the treatment of heart problems, digestive disorders, inflam- into that person’s mind. If it concludes that someone needs help, mation, and other mental and physical maladies. should it alert a family member, physician, or even law enforce- In the case of tinnitus, researchers are stimulating the vagus ment? Clearly, there are ethical questions to answer. Early inter- nerve to boost the activity of neurotransmitters, which are vention and knowledge is an enormous benefit, but it will come helpful in learning, memory, and bootstrapping the brain to at a cost: Either we’ll have to be willing to give up our privacy essentially rewire itself when necessary, a phenomenon called or invest in a better infrastructure to protect it. Some questions neuroplasticity. Such stimulation through hearables could also raised by AI-powered hearables aren’t easily answered. be used to address post-traumatic stress disorder (PTSD), to I am confident that we can meet these challenges. The ben- treat addiction, or to enhance learning of physical movements. efits of hearables will far outweigh the negatives—and that’s a strong motivation for doing the work needed to sort out the Privacy and security are two big interrelated challenges fac- issues of privacy and security. When we do, hearables will ing developers of hearables on the path to widespread adop- constantly and silently assess and anticipate our needs and tion. While there are many benefits that may come from having state of mind while helping us cope with the world around us. wearables constantly monitoring our internal states and our They will be our true life partners. n reactions to our surroundings, people may be reluctant to

submit to that kind of constant scrutiny. Businesses, too, will ↗ POST YOUR COMMENTS at http://spectrum.ieee.org/hearables0519

SPECTRUM.IEEE.ORG | MAY 2019 | 43

THE MARVELOUS MR. MEMS An ink stain led Kurt Petersen, 2019 IEEE Medal of Honor recipient, to a lifetime of building microdevices

By Tekla S. Perry Photography by Peter Adams

SPECTRUM.IEEE.ORG | MAY 2019 | 45 46 | MAY 2019 | SPECTRUM.IEEE.ORG IT WAS 1975, and Kurt Petersen was a smart young researcher, fresh out of the Ph.D. program in electrical engineering at MIT and working in the optics group at IBM’s Almaden, Calif., research center. And he was bored. Roaming the massive complex one day, he came across a huge black stain on the linoleum tiles of an otherwise nondescript hallway. That stain would change his life and the course of an entire industry.

In search of the source of the stain— Petersen then set out to build his first Petersen spent the next five years cre- he was that bored—Petersen walked device. Looking at some of the inkjet noz- ating as many different types of micro- into the nearest lab. The stain, he found zles under a microscope, he says, “I could mechanical devices out of silicon as he out, came from an ink spill. The lab was see that when there was a defect, it left could, including accelerometers and developing inkjet printer nozzles by little freestanding, incredibly thin silicon electrical switches. He moved out of the etching holes in silicon. dioxide beams hanging over. I thought, optics group into a custom-designed Etching holes in silicon? It hadn’t ever Wow, maybe these tiny mechanical struc- laboratory that was just big enough to occurred to Petersen that you could etch tures can move around. Maybe they could accommodate him and an intern. holes in silicon. But then he remembered deflect light, and I could build a light mod- a poster he’d seen earlier that year, about ulator.” He used a process that’s similar to Based on his deep dive into an effort to create a miniature acceler- one used in MEMS manufacturing today, B the literature and his own ometer on silicon. Suddenly the bigger patterning a layer of silicon dioxide on work, Petersen wrote an picture snapped into focus: People were top of a sacrificial layer of epitaxial sili- internal report on the actually building tiny mechanical gad- con, and then etching away the sacrifi- emerging technology. “There were lots gets, their parts just a few micrometers cial layer. What’s left is a silicon dioxide of mechanical structures that would across, out of silicon. Today we call those cantilever with a thin metal layer on top. potentially be of interest to IBM,” he devices microelectromechanical sys- It took him three months to produce says, such as heads for optical and tems, a.k.a. MEMS. And Petersen wanted a few of the microscopic modulators, mechanical disk drives and more sophis- to build MEMS, too. each about 100 micrometers long and ticated inkjet nozzles. The company He launched himself down a new career 0.5 micrometers thick. He took them to wasn’t interested. path, building MEMS technologies— the lab that housed IBM’s scanning elec- Petersen was disappointed, but he also including the devices that now screen tron microscope, where a technician realized that the devices weren’t key to every letter mailed in the United States helped him install an electrical wire so any of IBM’s businesses. So he rewrote for anthrax—and founding MEMS he could apply a voltage to the devices his report, removing IBM-proprietary startups. For this contribution, and and watch them move. information, and submitted it to the many more, Petersen will receive the “She was fascinated,” Petersen recalls. Proceedings of the IEEE—all 50 pages of 2019 IEEE Medal of Honor. “She said she’d never seen anything move it. The article, “Silicon as a Mechanical under the microscope.” Material,” became the cover story in May Soon after his encounter 1982 and helped establish MEMS as its S with the ink stain, Petersen own branch of technology. began reading everything The paper was comprehensive, look- he could about making tiny ing at the mechanical properties of mechanical devices out of silicon, in jour- integrated circuit materials and vari- nals like IEEE Transactions on Electron ous ways of etching those materials into Devices, Applied Physics Letters, and the shapes and structures. “It also specu- Journal of the Electrochemical Society. lated on things that came much later, like Back then the category didn’t even have deep reactive-ion etching, which really a name, and there were only a couple of revolutionized the field,” he says. “Even MEMS-type products on the market. He today, people tell me reading that article discovered that “there were dozens of is what got them interested in MEMS.” people all over the world who had done “We all read the paper when I was in different kinds of mechanical devices grad school,” says Greg Kovacs, now chief on silicon, but there was no community. technology officer for SRI International, MUST-READ: Kurt Petersen’s May 1982 cover The people doing the work didn’t know article for Proceedings of the IEEE established in Menlo Park, Calif. “He had a huge role about most of these other people.” him as a tech evangelist for MEMS. in MEMS. What he did was more impor-

SPECTRUM.IEEE.ORG | MAY 2019 | 47 700 µm 40 µm

100 µm 100 µm

300 µm KURT PETERSEN (5) PETERSEN KURT

48 | MAY 2019 | SPECTRUM.IEEE.ORG tant, really, than founding the field— panies to produce samples, including into the ranks of the “MEMS million- he inspired it. He is a superhero to me.” light modulators like those Petersen had aires.” The NovaSensor product line is After the Proceedings paper came out, made at IBM. And they began develop- now sold by Amphenol. Petersen got invited to speak at confer- ing their own MEMS devices. Petersen stayed on for several more ences around the world, and researchers “We were demonstrating a lot of years to collect on his share of equity. Dur- started showing up at Almaden to see devices,” Petersen says, “but we weren’t ing that time, he focused on fusion bond- him. “All sorts of people who were doing getting anything into production.” A ing, which involves etching two wafers crazy things—like microfluidic cryogenic tire-pressure sensor for the trucking with different patterns and then joining refrigerators—were somehow finding me,” industry came close, but then the execu- them together. The process allows you he says. Seemingly overnight, he’d turned tive they’d been working with died. Not to create extremely intricate devices like into a technology evangelist for MEMS. much else even approached commercial- gyroscopes. A photo of one of the first The field grew steadily throughout the ization, a problem Petersen attributes to devices made with that process—it’s the 1980s. At the time Petersen’s paper was the fact that neither he nor Knutti had leaf-spring structure shown at left— published, perhaps 30 or 40 researchers manufacturing experience. appears on his business cards to this day. around the world were working with the The contract work kept Transensory By the time Petersen left NovaSensor technology. By 1990, he estimates there afloat, but Petersen wanted to get his in 1995, MEMS pressure sensors were were some 600. Pressure sensors for dis- own MEMS devices to market. It was being used in a variety of systems, posable blood pressure monitors and new time for startup No. 2. including scuba diving equipment and fuel-control carburetors came on the mar- HVAC controls, while MEMS accelerom- ket. The aerospace industry began using In 1985, Petersen, Janusz eters were beginning to appear in crash- accelerometers based on MEMS. The first I Bryzek, and Joseph Mallon sensing systems for automotive airbags. micromachined inkjet printheads went started NovaSensor, with into mass production. A number of start- $5 million from oil-field ser- Petersen didn’t have any- ups appeared, eager to run with the tech- vices giant Schlumberger. B ryzek had P thing lined up when he left nology. The field got its current moniker previously cofounded two companies NovaSensor. Allen Northrup, at a 1987 National Science Foundation that developed MEMS pressure sensors. a researcher at the Lawrence workshop, Petersen says. “Janusz and his partners had the produc- Livermore National Laboratory, sug- Not surprisingly, several companies tion and manufacturing DNA” that gested to him that MEMS devices could approached Petersen. He finally took Transensory lacked, Petersen says. dramatically speed up the polymerase the bait, joining Jim Knutti to found NovaSensor set out to build three types chain reaction (PCR), a relatively new Transensory Devices in 1982 to develop of pressure sensors: one for the aero- means of duplicating sequences of DNA. and manufacture MEMS devices. space industry, another for the oil indus- Bill McMillan, who worked in biotech Leaving the stability of a corporate try, and a high-temperature pressure and was a friend of Petersen’s wife, con- research job, he recalls, “was intimi sensor without a specific market in mind. firmed the promise of PCR. So Petersen dating.” Petersen had two young This last device proved to be the biggest began sketching out a plan to reduce the sons, so financial security was a con- success. It even went into the tires on size and cost of PCR machinery, aiming cern. The startup’s funding—just under the space shuttle. “We found a way to to make a handheld gadget that could US $1 million—eventually came from out- isolate the resistors from the substrate be in every doctor’s office. of-state oil, not Silicon Valley investors. using a MEMS process. We bonded a He and McMillan had lunch at the “There were startups happening in Silicon single-crystal silicon wafer onto another California Café in Palo Alto. “I gave him Valley, but it wasn’t the machine it is today. oxidized wafer with pressure-sensor my little pitch, and he started drawing Getting funding was difficult,” he says. diaphragms, then etched away most of a business plan on the paper place mat,” The team moved into a 280-square- the top wafer, except for the resistors,” Petersen says. He still has the place mat. meter fab in Fremont, Calif., and built Petersen recalls. He believes the sensors Petersen’s 1982 paper had hinted at the some of their own equipment, includ- were the first silicon-on-insulator devices, possibilities of deep reactive-ion etching wafer-bonding machinery for encap- which have since become common. ing (DRIE), for creating much deeper sulating and protecting silicon wafers. Lucas Industries acquired NovaSensor holes and trenches in silicon than tra- They took contracts from bigger com- in 1991, a move that lifted Petersen high ditional chipmaking processes can. He began applying DRIE to microfluidic chips, which send tiny volumes of liq- THE MEMS OF MR. MEMS: Microelectromechanical devices built by Kurt Petersen or at one of his companies include [clockwise from top left] a catheter-tip pressure sensor made uids down precise channels. with silicon fusion bonding, manufactured in about 1990 by NovaSensor; a CMOS/MEMS “We got the idea that we could use integrated accelerometer built at IBM Research; a prototype microfluidic structure made MEMS technology and microfluidics to with deep reactive-ion etching, made in about 1993 at NovaSensor; a heated bridge element for a mass-flow sensor, manufactured in about 1984 at Transensory Devices; a leaf-spring heat and cool samples very rapidly, poten- structure made from single-crystal silicon, demonstrated in about 1993 at NovaSensor. tially making PCR so small and fast that

SPECTRUM.IEEE.ORG | MAY 2019 | 49 you could use it for diagnostics in a doctor’s office,” Petersen says. To commercialize the technology, Petersen cofounded Cepheid in 1996, licensing the base technology from Livermore Labs. By 1997, the company had secured $3.2 million in funding from the U.S. Department of Defense, which was eager to acquire a bioweapons detector. The first device Cepheid came up with, the Smart Cycler, used a MEMS structure to heat and cool microliters of liquids quickly and a fluorescence sensor to monitor the progress of the reaction. It wasn’t a handheld gadget, but that didn’t matter. It was more important to automate the PCR process. Cepheid’s next product, called the GeneXpert, aimed to make PCR even sim- pler. It automatically extracted the DNA from a biological sample and then added the reagents needed for the desired test. The company went public in June 2000, just as the tech bubble was bursting. “We were one of the last companies that man- aged to get out an IPO” before the market dried up, Petersen says. With cash in the bank from the public offering, the team moved the Smart Cycler into production, and as the summer of 2001 came to a close, they had shipped about 80 systems. The development of the GeneXpert was still chug- TECH ANGEL: These days ging along, with the first prototype due Petersen invests in and advises a number of startups, meeting in December 2001. with several each day. “It’s too much fun,” he says. Then came the anthrax T attacks. In late September and October of 2001, letters containing anthrax spores the testing process in December 2001. By 2003, Petersen was were mailed to members of the U.S. news “It went perfectly,” Petersen says. B ready for the next thing. This media and the U.S. Senate, eventually After months of additional tests, the time, he wanted to explore infecting more than 20 and killing 5. company partnered with Northrop silicon resonators, devices Cepheid had already established Grumman to build a PCR biodetector that generate constant frequencies use- anthrax as one of the substances its that could easily be hooked up to a mail- ful for precise timing. “I had built some technology could quickly detect, and sorting machine. The product rolled out of the first MEMS resonators when I was the company was suddenly big news. in 2003, and today all mail in the United at IBM, but they weren’t very good. They “We were doing live PCR assays on ‘Good States is still screened for anthrax by couldn’t compete with a quartz-crystal Morning America’ and on CNN with Cepheid machines, Petersen says. Now, oscillator,” he says. Dr. Sanjay Gupta,” Petersen recalls. the company’s systems are mainly used Three researchers—Tom Kenny, Markus The U.S. Postal Service, concerned for medical diagnostics, including strep, Lutz, and Aaron Partridge—had figured about future biological attacks through norovirus, flu, and chlamydia. The com- out a better way. “These guys were mak- the mail, invited anybody with biodetec- pany sells over 20 tests approved by the ing the resonator out of s ingle-crystal tor technology to come demonstrate their U.S. Food and Drug Administration for silicon, and that’s the world’s most per- stuff. Cepheid put its machines through use with Cepheid machines. fect material,” Petersen says. “Poly

50 | MAY 2019 | SPECTRUM.IEEE.ORG Date of birth: 13 February 1948 First electronics job: Summer intern, Favorite kind of music: 1960s and Kurt Birthplace: San Francisco Berkeley RAD Lab ’70s dance music Petersen Family: Wife (Carol), two adult sons Current job: Angel investor Favorite Movie: Blade Runner (1982) Education: B.S. in electrical Patents: About 40 Pet peeve: Startups that don’t respect engineering, University of California, Most recent books read: Valley of operations Berkeley, 1970; Ph.D. in electrical Genius (Hachette, 2018), by Adam IEEE 2019 Medal of Honor engineering, Massachusetts Institute Fisher; Bad Blood: Secrets and Lies in a citation: “For contributions to and of Technology, 1975 Silicon Valley Startup (Knopf, 2018), by leadership in the development and First job: Firefighter, California John Carreyrou commercialization of innovative Department of Forestry and Fire Favorite book: Sex, Time and Power technologies in the field of MEMS” Protection (Viking, 2003), by Leonard Shlain

crystalline materials shift a little bit at the is implanted, “the body starts walling it because he is so humble. Being around grain boundaries when they get stressed. off with collagen, eventually preventing him is like putting on your favorite pair Even just an atom or two shifting over glucose in the blood from reaching the of slippers.” time causes changes in the mechanical sensor,” he explains. Ganapathi agrees. “It’s not often that properties.” Single-crystal silicon doesn’t So McMillan teamed up with Duke you find someone who has been as suc- change over time, but its resonant fre- University researcher Natalie Wisniewski, cessful as Kurt has and is so universally quency does change with temperature, and they came up with a solution that liked,” he says. so the challenge was how to cancel out used a structured hydrogel to avoid the the temperature dependence. foreign-body response and a fluorescent These days, Petersen is Petersen, Kenny, Lutz, Partridge, and readout to measure the concentration of T back to angel investing, tar- Joe Brown, a former IBM colleague who glucose. Petersen went back to his optics geting MEMS companies had worked with Petersen at Transensory roots to help develop the product, stay- along with medical devices and NovaSensor, met for yet another ing a year at the startup, Profusa. The and biotech. He says he’s invested in meal at the California Café, and drafted company now has about 30 employees about 70 companies, and nearly half a business plan on yet another place mat. and $100 million in funding. have turned out to be successful, reap- Robert Bosch GmbH owned some of the And that, Petersen says, was going ing a 350 percent return on his invest- core intellectual property, so in addition to be his last full-time gig. “I just didn’t ments. That’s an impressive track record. to bringing on investors, Petersen had to want to do the day-to-day company stuff According to a recent study, a more typi- convince Bosch executives in Germany anymore. I started angel investing and cal return for a long-term angel investor to license the technology. that turned out to be much more fun.” with a broad portfolio is 250 percent. “I had a big meeting with their board Still, he couldn’t resist one more team. “The guy has an uncanny ability to of directors in Stuttgart,” he says. “I told Two Berkeley students had developed smell out what can be a product. It can them, ‘This is what I do. I start compa- technology for MEMS resonators, but be 3 or 15 years down the road, but he’s nies. My last one screens all the U.S. they were struggling to turn it into a busi- got a nose for it,” says Ganapathi. mail for anthrax.’ ” The board agreed ness. Petersen and K.G. Ganapathi joined Petersen joined the Silicon Valley not only to license the technology but their company, which was renamed Band of Angels in 2012, an invitation- also to make a major investment. Verreon, and Petersen served as CTO, only group of about 200 investors who The new company, SiTime, launched helping to coordinate the company’s meet regularly to hear pitches and in December 2004, aiming to transform sale to Qualcomm in 2010. share information. He now heads up the multibillion-dollar timing industry It was Petersen’s third go-around as CTO the Band’s hardware subgroup. He also from quartz to silicon. The company or the equivalent. In all his startups, he serves on the boards of two companies shipped its first resonators in 2007. claimed the CEO title only once, at SiTime. and as a mentor at a dozen others. He Today, its MEMS oscillators generate “At NovaSensor, two of the other guys meets in person with several of his advi- timing signals in mobile devices and wanted to be president,” says Roger Grace, sees every day, keeping in touch with many other electronic instruments. a marketing consultant who worked with those at Canadian and East Coast com- Things at SiTime were running the company. “Kurt didn’t care. He took panies by phone. smoothly in 2008 when McMillan, one of the CTO title. He’s not an ego-driven guy.” At 71, Petersen does not see retirement Petersen’s Cepheid cofounders, came to “There’s not one person in the MEMS on the horizon. “The entrepreneurs are him with another startup idea—building world that has anything other than energetic and motivated and ambitious, an implantable continuous glucose mon- wonderful things to say about Kurt, and it’s too much fun to be around them,” itor. “People had been trying to do that because he is just so kind, thoughtful, he says. n for 30 years, and nobody had been suc- and helpful,” says Grace. “There are ↗ POST YOUR COMMENTS at https://spectrum.ieee.org/ cessful,” Petersen says. Once the sensor a lot of smart guys, but he is unique ieeemedalofhonor0519

SPECTRUM.IEEE.ORG | MAY 2019 | 51 Best New Journal in STM 2015 JOURNEY TO THE CENTER OF THE SOLAR SYSTEM CONTINUED FROM PAGE 37 |

involved heating the array under vacuum while exposing it Become a to intense ultraviolet light, provided by light-emitting diodes. Some degradation of the solar panels would still occur, just as it does for other sorts of electronic components when they are published author “burned in,” but this would be a small price to pay for avoid- ing dangerous amounts of darkening later during the mission. in 4 to 6 weeks. Of course, we needed to be sure our strategy would actually work. To test the theory, we had to place the arrays in an envi- Published online only, IEEE Access is ideal ronment that resembled what they would experience close for authors who want to quickly announce to the sun. And such conditions are not so easy to come by. To meet that objective, we used 80 sets of eight mirrors. recent developments, methods, or new Each set could be individually rotated to reflect sunlight on products to a global audience. a fixed target, even as the sun moves. Such devices, called heliostats, are sometimes used to provide daylight in places IEEE Access is a multidisciplinary that would otherwise remain in the shadows. Large num- journal that allows you to: bers of them are employed at solar-thermal energy plants to focus sunlight on a central tower. We set these heliostats up • Reach millions of global users through the at a facility in New Mexico that was built specifically for this IEEE Xplore® digital library with free access to all testing, where the solar panels could be held under vacuum • Submit multidisciplinary articles that do not fit while they were exposed to concentrated sunlight. Such a use of heliostats, to concentrate sunlight on a space- neatly in traditional journals craft’s solar array, was clearly an odd one. But it worked • Expect a rapid yet rigorous peer review— marvelously. By the time the probe was assembled, its photo a key factor why IEEE Access is included in voltaic panels had experienced conditions and exposure Web of Science (and has an Impact Factor) durations never before used to test a full-size solar array • Establish yourself as an industry pioneer by destined for space. contributing to trending, interdisciplinary topics with all the precautions we took and all the testing we car- in one of the Special Sections ried out, we were fully confident that the panels wouldn’t suf- • Integrate multimedia and track usage and fer from anomalous darkening. But we still needed to be sure citation data for each published article that the cells in them would remain sufficiently cool. • Connect with readers through commenting A typical spacecraft solar array manages its temperature • Publish without a page limit for passively: The absorbed light heats the solar cells, which are typically mounted on one side of a graphite-epoxy composite only $1,750 per article panel. Heat conducts through the honeycomb mesh of the panel and radiates out into space from both the front and back sides. A typical solar panel in space operates at a temperature between –70 and 100 °C—low enough not to require IEEE Access... any special materials or coatings. a multidisciplinary The photovoltaic panels on the Parker Solar Probe are differ- open access ent. Their solar cells must be actively cooled. For that, the cells journal that’s were mounted to sheets of titanium containing a large number worthy of of narrow channels through which cooling water flows. It’s not the IEEE. unlike the system used to keep the engine in your car from overheating. The cooling system on the Parker probe doesn’t use antifreeze, though. It uses ordinary deionized water, just as you might use in a steam iron. And just like the cooling system in your car, the system is pressurized to prevent the cooling fluid from boiling at high temperatures. At the probe’s closest approach to the sun, the cooling system Learn more at: must be able to handle about 5,900 watts of heat load on the ieeeaccess.ieee.org 17-PUB-013 3/17 two solar wings. This heat is shed using really just embarked ↗ POST YOUR women who have together contributed COMMENTS at http:// four separate radiators, each about one on its multiyear mis- spectrum.ieee.org/ some 10 million hours to the immense parkerprobe0519 meter square, located in the shadow of sion to explore the engineering effort that was needed to the probe’s heat shield. 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At the same time, two of the four radiators were similarly heated by turning the spacecraft so that they weren’t in the shadow of the heat shield. After these components became sufficiently warm, valves opened to allow the preheated water to flow from the accumulator. After half the cooling system was loaded with water, spacecraft operations commenced. Over 75 New Features & Apps in Origin 2019! For a FREE 60-day Some weeks later, after the probe was Over 500,000 registered users worldwide in: evaluation, go to closer to the sun, the other two radia- ◾ 6,000+ Companies including 20+ Fortune Global 500 OriginLab.Com/demo tors were warmed in the same manner ◾ 6,500+ Colleges & Universities and enter code: 8547 and filled with coolant. This cooling sys- ◾ 3,000+ Government Agencies & Research Labs tem ensures that the highest temperature that any photovoltaic cell will ever reach is 120 °C. 25+ years serving the scientific & engineering community the parker probe, which has been in space for almost nine months now, has

SPECTRUM.IEEE.ORG | MAY 2019 | 53 Micron Technology, Inc., is seeking the below positions for its semiconductor R&D facility in Boise, ID; its manufacturing facility in Manassas, VA; and its sales and design facilities in Folsom and Milpitas, CA; and design facilities in Austin, TX and Longmont, CO; and worksites in Irvine, CA; Novi, MI; and Allen, TX. The following Micron subsidiaries are also seeking positions: Micron Semiconductor Products, Inc., at its headquarters in Boise, ID; and sales facilities in Meridian, ID; and Folsom and Milpitas, CA. ENHANCE YOUR IEEE Electrical, Electronics, Communications, Chemical, MEMBERSHIP BY JOINING THE Industrial, Mechanical, Materials, Computer System Power & Energy Society Analysts, and Software Engineering; Physics, Materials Science, Engineering Manager and other related Engineering occupations. Marketing, Sales, Logisticians, Help shape the future Finance, Accounting, and other related business positions. of the industry and give your career a boost Please submit your resume online: http://www.micron.com/jobs Join the engaged members of PES who are advancing innovation and Resume and/or cover letter must reflect each requirement or deepening their expertise in important it will be rejected. Upon hire, all applicants will be subject to areas such as: drug testing/screening and background checks. • Renewable energy Note: Some of these positions may require domestic and • Bulk energy storage international travel for brief business purposes. Please • Distributed energy resources read the full job description when applying online for such • Smart grids requirements. More Power to the Future™ EOE Learn more: ieee-pes.org/members

Lecturer Position The Department of Electrical Engineering seeks applications from outstanding candidates to teach and assist in the development of courses. Depending on the qualifications and interests of the applicant and the needs of the department, job responsibilities will include such activities as teaching and developing lecture classes; teaching and developing lab-based classes; supervising graduate-student teaching assistants; grading problem sets and lab assignments; supervising students in the grading of problem sets and lab assignments; developing and maintaining online curricular material; classroom and lab demonstrations; and supervising undergraduate ILLUMINATE EDUCATE ENGAGE ENERGIZE research projects. An advanced degree in Electrical Engineering, The IEEE Foundation is leading a special campaign or related field, is required (PhD preferred). Exceptional candidates who can only teach on a to raise awareness, create partnerships, and generate financial part-time basis will be considered. resources needed to combat global challenges. The position is renewable for 1-year terms depending on departmental need and satisfactory performance. Our goal is to raise $30 million by 2020. To apply, please submit a cover letter, CV, and contact information for three references to https://www.princeton.edu/acad-positions/ DONATE NOW position/11241. ieeefoundation.org This position is subject to the University’s background check policy.

54 | MAY 2019 | SPECTRUM.IEEE.ORG Chair Professor/Professor/ Associate Professor/ Assistant Professor Department of Biomedical Engineering Duties Professor/ Associate Professor/ Assistant Professor Teach undergraduate and postgraduate courses, supervise research students, School of Microelectronics conduct research, and perform any other duties as assigned. Southern University of Science and Requirements Technology (Shenzhen, China) Applicants with a PhD and strong background in Biomedical Engineering. Post Specifications Preference will be given to candidates with specialties in the areas of Biomedical School of Microelectronics (SME) National Exemplary School of Microelectronics, Imaging and Bioinstrumentation, Cell/Tissue Engineering and Biomechanics, Southern University of Science and Technology (SUSTech) invites highly qualified Robotics and Artificial Intelligence for Biomedical Applications, and Biosensors and candidates to fill multiple tenure-track/tenured faculty positions in the areas of Health Informatics. Candidates must be committed to high quality teaching at both (but not limited) Emerging Microelectronic Devices (Wide-bandgap, Nonvolatile undergraduate and graduate levels. memory, MEMS Sensor), and IC-Chip Designs (Future Computing/Communication/ Outstanding candidates in other areas will also be considered. Successful candidates Biomedical SoC). are expected to possess a solid disciplinary foundation and demonstrated Junior applicants should have (i) a PhD degree in related fields; and (ii) outstanding potentials/records of outstanding scholarship in both teaching and research. potential in teaching and research. Candidates for senior post are expected to have Salary and Conditions of Service demonstrated exceptional academic leadership and strong commitment to be Remuneration package will be driven by market competitiveness and individual excellent in teaching, research, and services. performance. Excellent fringe benefits include gratuity, leave, medical and dental schemes, and relocation assistance (where applicable). Initial appointment will be Applications made on a fixed-term contract. Submit (in English, PDF version) a cover letter, a statement in research and teaching, a CV plus copies of 3 most significant publications, and contacts of three Information and Application referees to: [email protected] entitled with “Apply for Faculty Position”. Further information on the posts and the University is available at http://www.cityu. Applicants are required to specify the rank of the position in their letter of edu.hk, or from the Department of Biomedical Engineering, City University of Hong application. The positions will be open until they are filled by appropriate candidates. Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (http://www.cityu.edu.hk/bme; email : [email protected]). For more information, please visit http://ohr.sustc.edu.cn/sustczp/product/ To apply, please submit an online application at http://jobs.cityu.edu.hk, and recruit/a.do?action=toZPGWList2&entityId=T_RECRUIT_PLAN&postType=2&se lectedId=1009881. include a current curriculum vitae. Nominations can be sent directly to the Department Head (email: [email protected] ). Applications and nominations Salary and Fringe Benefits will receive full consideration until the positions are filled. The University's privacy Salary and startup funds are highly competitive, commensurate with experience policy is available on the homepage. and academic accomplishment. All regular faculty members will join the tenure- track system in accordance with international practice for progress evaluation and Worldwide recognition ranking 55th, and 5th among top 50 universities under age 50 promotion. Applicants are encouraged to check out the details about the university (QS survey 2019); 1st in Biomedical Engineering in Hong Kong and 34th worldwide at: http://www.sustech.edu.cn. (ARWU survey 2018).

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In 1983, Belle became the first computer chess game to earn the title of chess master. Employing a COLD WAR brute-force approach to the game of kings, it won numerous championships against other computers as well as humans. The brainchild of Bell Labs researchers Ken Thompson and Joe Condon, Belle became so famous CHESS that it was invited, along with Thompson, to come to Moscow for a series of demonstrations. But the computer fell victim to Cold War tensions and was confiscated by customs officials at John F. Kennedy International Airport. When Thompson explained to his Moscow hosts that Belle had been unavoidably detained, the head of the Soviet chess club inquired, “Do you suppose Reagan did this to outlaw chess in the United States?” ■

↗ For more about Belle, see https://spectrum.ieee.org/0519pastforward ADAMS PETER

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85514 IEEE Because-LTC-Spectrum2.indd 1 85514 IEEE Long Term Care Ad (5/19) 3/18/19 3:16 PM Trim Size: 7.875” x 10.5”; Bleeds: .125, 8.125” x 10.75” Live Area: 7” x 10”; 4 color process, cmyk A robot that sees, acts, and learns, programmed in an afternoon.

That’s Model-Based Design.

To create an advanced humanoid robot that can perceive, throw, and catch a ball, engineers at DLR used Model-Based Design with MATLAB® and Simulink®. Result: the team could integrate control and vision for catching, optimize the throwing trajectory, generate embedded software, and verify it worked — in one afternoon.

mathworks.com/mbd

Photo of Agile Justin autonomous robot courtesy of German Aerospace Center (DLR), Robotics and Mechatronics Center

Client Name: The Mathworks Cosmos Communications 1 Q1 Q2 CMYK ej REQ #: 110718A 38683a2 11.28.18 133 4 Title: na-mbd-robot-7.875x10.75 Page 4/c Size: 7.875” x 10.75”

This advertisement prepared by: Elizabeth Putnam Creative Services Project Manager MathWorks 1 Apple Hill Drive Natick, MA 01760 508-647-0589 [email protected]