AUTUMN 2016 ISSUE 20

DEPARTMENT OF ENGINEERING NEWS Science behind remarkable new Wall of Death motorcycle world record Page 3

Could future buildings be made with bone and eggshells? Page 5

Smart glass goes from clear to opaque and back again – 27 million times Page 21

Laser technique promises super-fast and super-secure quantum cryptography Page 24 In this issue Welcome The upcoming book by Haroon Ahmed, Cambridge Science behind remarkable new Wall 3 of Death motorcycle world record Engineering: The First 150 Years, is nearing Sir James Dyson opens invention 4 completion. Spanning the breadth of research powerhouse at the University of Cambridge and the history of the Department and looking Dreaming big with biomimetics 5 toward the future, the book commemorates the Student projects find a home as new 6 achievements of all of the notable figures who have Oatley Garage opens studied, researched and worked in Cambridge to PhD student Sakthy Selvakumaran 7 advance the field of engineering. is on the Forbes 30 under 30 list Venice Architecture Biennale 2016 8 Turning through the pages of the book, I was struck Think small: Diminishing returns 9 by the many contrasts and parallels I find between the in neuroscience current Department and its history. We have always Interview with Dr Jenni Sidey 10 emphasised greatness, of course, but it’s clear that our Women in engineering celebrated 11 focus on excellence won’t slow down any time soon! IfM Design Show 2016 12-13 Cambridge spin-out secures $3m 14 A very striking contrast is seeing the increasing diversity to improve oil recovery efficiency of the students and researchers as we move through Alumna Anya Jones Receives 15 history. There is a photograph of a large classroom here Presidential Early Career Award in the Department, taken in the 1920s, with only three female students grouped together at the Professor Sir David MacKay 1967–2016 16 front; the remainder of the 100 or so students were all male. Our current undergraduate intake Hackathon unleashes the power 17 includes 28% women, which is a great improvement, even though we still have some way to go. of wearables Consortium scores €9 million 18 The Department’s Women in Engineering initiative has grown substantially, conducting frequent for textile nanofibre research outreach events and lectures within the Department. This newsletter highlights this initiative – in Trimble partnership will advance 19 an interview with Dr Jenni Sidey, a recently appointed University Lecturer, on page 10 and a recap engineering and construction of a poster competition to raise awareness of women engineers on page 11. 50 years of tribology 20 Smart glass goes from clear to opaque 21 As you read through this edition of the newsletter, I invite you to consider supporting the Department and back again – 27 million times with your preorder of the Cambridge Engineering book. More than 600 people have already preordered UK steel can survive if it transforms 22 and will have their names (or someone of their choice) printed in the List of Supporters. itself, say researchers Honours, awards and prizes 23 Laser technique promises super-fast 24 Professor David Cardwell FREng and super-secure quantum cryptography

Cover image: Guy Martin on site at the Wall of Death where he attempted to break a world speed record live on Channel 4. Credit: Ryan Cambridge Engineering McNamara/Channel 4 The First 150 Years Editors: Jacqueline Saggers and Christopher Jablonski Preorder the book today to save £10 on the Department of Engineering published price. Until 30 November 2016, you University of Cambridge may have your name (or a name nominated by Trumpington Street you) printed in the book as an enduring record Cambridge CB2 1PZ of your links with Cambridge Engineering. Telephone: +44 (0)1223 748228 Email: [email protected] How to preorder www.eng.cam.ac.uk You can order securely online at www.tmbooks.com Design: www.cantellday.co.uk or by calling +44 (0)20 7336 0144. Printing: Sudbury Print Group © 2016 University of Cambridge and Contributors as identified. The content of Department of Engineering News, with the exception of images and illustrations, is made available for non-commercial re-use in another work under the terms of the Creative Find us... Commons Attribution-Non-Commercial-ShareAlike Licence (http://creativecommons.org/licenses/bync- eng.cam.ac.uk/Twitter eng.cam.ac.uk/Facebook sa/3.0/), subject to acknowledgement of the original L F author/s, title of individual work and the University www.cam.ac.uk/YoursCambridge of Cambridge. This Licence requires any new work I eng.cam.ac.uk/LinkedIn X eng.cam.ac.uk/YouTube with an adaptation of content to be distributed and For latest news re-licensed under the same licence terms. N eng.cam.ac.uk/Flickr I eng.cam.ac.uk/Instagram www.eng.cam.ac.uk/news

2 University of Cambridge Department of Engineering Issue 20 Autumn 2016 Ryan McNamara/Channel 4

Science behind remarkable new Wall of Death motorcycle world record

Dr Hugh Hunt, Reader in temporary blindness, difficulty breathing and record attempt. It was 37.5 metres in diameter eventually unconsciousness. and quite a dramatic sight. It was constructed Engineering Dynamics and When you’re riding the Wall of Death the out of upturned shipping containers, welded Vibration, writes about his centrifugal force pushes you outwards and together and lined with timber. A refuge for experiences consulting for a then friction holds you up. Imagine the wall paramedics was constructed in the centre so was wet and slippery – you’d slide right down. if anything went wrong, medical help could be Channel 4 programme about That’s why it was very important that the wall summoned in a matter of seconds. the infamous Wall of Death in was kept dry and free from dust and drops of Guinness World Records was present to oil. Clearly, the wall has to be built indoors and officiate – and required a speed over 60mph in The Conversation. we needed a very big hangar for that. either one of two attempts. In his first attempt, The training for a high-G environment Guy achieved 72mph and there was much The Wall of Death has been the most involves flights in stunt aircraft. During those celebration. But during his second attempt (on enigmatic dare-devil motorbike stunt for more Guy found himself passing out at around 7G – his own home-made bike), he reached 78mph, than 100 years. Motorcyclists ride around and it doesn’t bear thinking about what would smashing his own record. the inside of a vertical wall, rather like a huge happen if consciousness was lost when riding If anyone is going to break Guy Martin’s barrel, at speeds of around 30mph. Most Wall a motorbike at 80mph on the wall. record of 78mph then they will have to build of Death “drums” are about 32 feet (10 metres) a wall at least as big as the Lincolnshire one. in diameter. So how fast can you go? In training, Guy thinks he once reached a peak It was thought that no one has ever ridden Let’s assume that Guy doesn’t want to exceed of 85mph but he backed off quickly as he was the Wall of Death any faster than 45mph, 7G (remember that he’d be experiencing the blacking out at this speed. Perhaps on a bigger but during the record attempt, experienced extreme forces for far longer than someone wall a new record will be set, but building a motorcyclist Guy Martin attempted to reach on a rollercoaster – and having to control a bigger wall is quite an undertaking. I think the 80mph, a speed which would completely motorbike, too) and that he wants to ride at record is safe for a few years. smash existing records. So how did he do? 80mph. Using Newton’s differential calculus, it And how on Earth can a motorcycle ride turns out that the centrifugal G-force increases around a vertical wall? with the square of your speed and decreases in proportion to the Wall of Death’s diameter. The G-force awakens This means, for example, that if you travel The limiting factor for speed on the Wall of at 80mph on a 10-metre wall you’d experience Death is human physiology. When riding the 25G of centrifugal force – certain death. But wall, you are subject to high acceleration – or on a bigger wall, say 40 metres in diameter, www.cam.ac.uk/YoursCambridge G-force. Under these conditions, blood drains you’d experience 6.4G – just about within the R Guy Martin’s Wall of Death: Live can be seen away from your brain and eyes, much as water physiological limit. on Channel 4’s catchup service. is flung out of clothes during the spin cycle of With the maths in mind, a huge Wall of www.channel4.com/programmes/guy- a washing machine. It leads to tunnel vision, Death was constructed especially for Guy’s martins-wall-of-death-live

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 3 Sir James Dyson opens invention powerhouse at the University

of Cambridge Sindall Morgan Credit:

The engineering hub focuses A bridge link offers easy access to testing said: “The research taking place in this building on advances including laboratories housing world-class fluid dynamics exists at the very cutting edge of engineering machinery, aerodynamics equipment and areas excellence. Allied to new ideas generated smart infrastructure, electric for aeroacoustics analysis. within the Dyson Centre, this will produce vehicles and efficient internal The building itself is as smart as the minds not only world-changing discoveries and combustion systems. it houses: fibre-optic sensors in the foundation inventions, but the future generations piles, concrete columns and floor sections of engineers the world requires to address offer live data, about temperatures and strain – the major challenges of the 21st century.” Sir James Dyson opened some of the world’s providing a picture of how the building Head of the Department of Engineering, most advanced engineering facilities at the is behaving. The result is a building that’s Professor David Cardwell, said: “Collaboration University of Cambridge in May – giving the more of a living creature than a passive block is at the heart of solving global engineering institution’s students and academics the of material. challenges and the new James Dyson space and means to prototype, invent and Research undertaken in the hub will build on Building brings brilliant researchers from collaborate on cutting-edge research. a rich tradition of invention: Cambridge alumni across disciplines together with industrial The development has been funded by include internal combustion pioneer Harry practitioners to serve our cities, transportation an £8m donation from the James Dyson Ricardo and jet engine inventor Frank Whittle. and energy systems with novel techniques. Foundation – the largest gift ever received The Department is located at the heart “The adjoining Dyson Centre for by the Department. of the Cambridge cluster, Europe’s largest Engineering Design enables students to The Dyson Centre for Engineering Design technology cluster, which employs around express their creative talents and test their is the focal point for teaching Cambridge 57,000 people in more than 1,500 technology- engineering skills using high-tech and diverse students about the design process, providing based firms, which have combined annual machining and prototyping equipment. specialised printing machinery, scanners, lasers revenue of over £13 billion. Cambridge has Here we will also welcome schoolchildren and routers. It provides space for over 1,200 created over 1,500 spin-out companies over to see engineers at work and captivate the engineers to conduct their project work. the last decade, with a 97.4% five year survival next generation of competent engineers. An open plan design encourages the sharing rate, compared to 44.6% nationally. An updated and redesigned Engineering of ideas and a collaborative environment. Sir James said: “Developing the intellectual Library will guarantee flexible spaces for Student led projects housed within the centre property that will help Britain succeed in the collaborative as well as silent work spaces include solar powered electric racing cars, global technology race depends on applying for our students and researchers.” vehicles engineered for arctic ice, quad-rotor our brightest minds to ambitious and exciting Professor Dame Ann Dowling, President drones and helium balloon spaceflight systems. research projects. I’m hopeful that this new of the Royal Academy of Engineering, said: A separate new four-storey building, the space for Britain’s best engineers at the “Academic rigour must meet with practical James Dyson Building for Engineering, houses University of Cambridge will catalyse great invention. The Dyson Engineering Design postgraduate researchers and supports world technological breakthroughs that transform Centre and the James Dyson Building for leading research in areas including advanced how we live”. Engineering bridge the gap, encouraging materials, smart infrastructure, electric vehicles Vice-Chancellor of the University of engineers to apply their minds to creatively and efficient internal combustion systems. Cambridge, Professor Sir Leszek Borysiewicz, experiment and try new things.”

4 University of Cambridge Department of Engineering Issue 20 Autumn 2016 Credit: Shutterstock Credit: Dreaming big with biomimetics Could future buildings be made with bone and eggshells?

Dr Michelle Oyen, Reader to form the biological materials we’re made of, There are two ways to mimic natural tissues such as bone, cartilage, and muscle. materials. Either you can mimic the composition in Bioengineering for the In order to make biomimetic materials, of the material itself, or you can copy the Biomechanics Group, writes we need to have a deep understanding process by which the material was made. Since for The Conversation on how of how natural materials work. We know that natural materials are made by living creatures, natural materials are also “composites”: they are there are no high temperatures involved in researchers are looking for ways made of multiple different base materials, each either of these methods. As such, biomimetic to make new materials inspired with different properties. Composite materials materials – let’s call them “neo-bone” and “neo- are often lighter than single component eggshell” – take much less energy to produce by nature. materials, such as metals, while still having than steel or concrete. desirable properties such as stiffness, strength In the laboratory, we have succeeded in In 2007 alone, steel and concrete were each and toughness. making centimetre-scale samples of neo- responsible for more CO₂ emissions than the bone. We do this by preparing different entire global aviation industry. Before reaching Making biomimetic materials solutions of protein with the components that the construction site, both steel and cement Materials engineers have spent decades make bone mineral. A composite neo-bone must be processed at very high temperatures measuring the composition, structure and material is then deposited from these solutions – and this takes a lot of energy. So how can properties of natural materials such as in a biomimetic manner at body temperature. we reduce our dependence on these “dirty” bone and eggshell, so we now have a good There is no reason that this process – or an materials, when they play such a crucial role understanding of their characteristics. improved, faster version of it – couldn’t be in construction? For instance, we know that bone is scaled up to an industrial level. composed of hydrated protein and mineral, in Of course, steel and concrete are Copying life almost equal proportions. The mineral confers everywhere, so the way we design and Could the answer lie in developing new stiffness and hardness, while the protein construct buildings is optimised for these materials that are inspired by nature? This confers toughness and resistance to fracture. materials. To begin using biomimetic materials idea started to gain traction in the research Although bones can break, it is relatively rare, on a large scale, we’d need to completely community in the 1970s and really exploded and they have the benefit of being self-healing rethink our building codes and standards for in the 1990s, with the development of – another feature that engineers are trying to construction materials. But then, if we want to nanotechnology and nanofabrication bring to biomimetic materials. build future cities in a sustainable way, perhaps methods. Today, it forms the basis of a Like bone, eggshell is a composite a major rethink is exactly what’s needed. The new field of scientific research: namely, material, but it is around 95% mineral and science is still in its infancy, but that doesn’t “biomimetics” – literally “copying life”. only 5% hydrated protein. Yet even that small mean we can’t dream big about the future. Biological cells are often referred to as “the amount of protein is enough to make eggshell building blocks of life”, because they are the very tough, considering its thinness – as smallest units of living matter. But to create a most breakfast cooks will have noticed. The multi-cellular organism like you or me, cells next challenge is to turn this knowledge into R must clump together with a support structure something solid. www.eng.cam.ac.uk/profiles/mlo29

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 5 , The Oatley family in front of the garage

Student projects find a home as new Oatley Garage opens

Student projects such as Full Blue Racing and Cambridge University Eco Racing have had to build in any area they could find – with no easy storage solutions for cars between competitions – until a generous donation from the Oatley family provided a dedicated space for these projects.

The Oatley Projects Garage was officially Several members of the Department opened in a ceremony on 15 February by of Engineering were present at the opening, benefactors Geoff and Jean Oatley. Also including Professor David Cardwell (Head We wanted“ to thank the present were son Joe Oatley, Department of Department), Mr Philip Guildford (Director Engineering Department at of Engineering graduate (1987) and now CEO of Research), Dr Claire Barlow, Dr David Cole, Cambridge for what they did of Cape plc., international provider of support Dr Paul Heffernan, Dr Richard Roebuck, Dr for our son, Joe, setting him services to the energy and mineral resources Hugh Shercliff, Dr Ronan Daly, Dr Simon Guest on a brilliant career path. sectors; Joe’s wife Jane, graduate of the and Tom Ridgman, as well as representatives Department of Veterinary medicine; from student teams Full Blue Racing and Geoff and Jean Oatley and several other family members. Cambridge University Eco Racing. The garage’s electric door opened to “We wanted to thank the Engineering reveal ‘Evolution’ the Eco Racing Team’s solar Department at Cambridge for what they University Entrepreneurs. More information car, recently returned from the World Solar did for our son, Joe, setting him on a brilliant about the Department’s student-led societies Challenge in Australia, alongside the Full Blue career path,” said Geoff and Jean. Their gift can be found at the URL below. Racing Team’s FBR16 (Formula 1 car). The not only provides for the cutting-edge garage- student team members were able to thank cum-workshop for student projects but Geoff and Jean personally, and explain how enables the Department’s outreach work with valuable the new garage is to their projects; the local community. this is their first ever garage area on site – it will The Department of Engineering hosts save the project teams huge amounts of time or is associated with a number of student- R and money. led societies in addition to Full Blue and teaching.eng.cam.ac.uk/content/student-led- The Oatley grandchildren Sam, Sophie Eco Racing, such as Cambridge University societies and Patrick tried out both cars and later built Spaceflight, the Cambridge Autonomous Photo gallery of the opening of the Oatley their own mini solar cars in the Dyson Centre Underwater Vehicle Team, Engineers Without Projects Garage at: for Engineering Design under the supervision Borders, the ecohouse initiative, Cambridge www.flickr.com/photos/cambridgeuniversity- of Outreach Officer Maria Kettle. University Autonomous Flight and Cambridge engineering/albums/72157663344154403

6 University of Cambridge Department of Engineering Issue 20 Autumn 2016 , Sakthy Selvakumaran

ALUMNI UPDATE PhD student Sakthy Selvakumaran is on the Forbes 30 under 30 list

PhD student Sakthy Sakthy is pleased at the recognition London), inspection design and assessment that becoming chartered has meant for her of various rail bridges owned by Network Rail, Selvakumaran, a Chartered saying: “I’m proud to be a Chartered Civil the design of various UK highway bridges Civil Engineer, is on the Forbes Engineer. It recognises that you have reached and civil infrastructure, and the design of a 30 under 30 list Europe 2016. a marker in your career that indicates that your tunnel and approach structures in Gibraltar. peers in the wider profession trust you to act In 2013 she was asked to join the Engineering as a professional engineer, to represent the Excellence Group of Laing O’Rourke, working The Forbes inaugural 30 Under 30 Europe profession. It’s by no means a mark that states on developing new design solutions and list looks at the brightest and most talented that you’ve learned all you need to know technologies to change the way infrastructure under-30-year-olds who are already shining in about being a Civil Engineer, but I like that is designed, constructed and maintained. their chosen career and changing our world. because it means that you’re always learning She re-joined the Department in 2015 to Sakthy, at the time of being shortlisted, new things and coming with new ideas.” undertake a PhD in Engineering. was an Innovation Engineer with civil Sakthy says she’s still not sure who put her engineering contractor Laing O’Rourke. Laing name forward and only found out she had O’Rourke and National Physical Laboratory are been nominated when someone contacted her currently sponsoring her to do an Industrial on behalf of Forbes to say that she had been Case PhD at the Department. During her shortlisted. As part of becoming one of the ‘30 I’m proud to be a Chartered Civil time at Laing O’Rourke, Sakthy was in the under 30’ she has been invited to a Summit in “ Engineer. It recognises that Engineering Excellence Group, and spent April along with other members on the list. you have reached a marker time on site helping to deliver the ExCeL A keen writer on her experiences, she has in your career that indicates Footbridge. She previously worked on the written articles in a several magazines and also that your peers in the wider project leading on its design in her role as a has a blog slot for the Huffington Post. Design Engineer for Ramboll. Sakthy graduated with an engineering profession trust you to act She developed and ran an education degree from the Department (2006-2010) as a professional engineer, initiative with Serious About Youth (SAY) called and has since worked as a civil and structural to represent the profession. ‘Construkt’ on behalf of Institution of Civil engineer in design consultancy and Sakthy Selvakumaran Engineers (ICE) who founded this scheme. She contracting applications across multiple roles is now influential in the further development and countries (including UK, Canada, Sri Lanka, of the scheme to enable young people to Peru and Spain). Significant projects include better understand different career pathways, the design and construction of ExCeL Bridge, R and is engaging with additional companies (a 34 metre long bridge installed as part of the www.eng.cam.ac.uk/profiles/ss683 and institutions to encourage them to construction of the new Crossrail station at www.huffingtonpost.co.uk/sakthy-selvakumaran become involved. Custom House, linking the station with ExCeL www.say-youth.org/home

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 7 w Credit: IwanCredit: Baan

Venice Architecture Biennale 2016

Entitled ‘Reporting From The Front’, the Venice Architecture Biennale 2016 is intended by director Alejandro Aravena to offer a new perspective on global issues.

Dr Matthew DeJong and his research group and expertise, and makes use of advancing are involved in two projects that are exhibited technology, to push the boundaries of at the Venice Biennale from 28 May to 27 compression-only forms. Within the exhibition, I am very excited“ to be involved November, 2016. One is entitled ‘Beyond two smaller prototype structures aim to show in these projects that apply Bending’, which uses various visual and how traditional floor systems made from tile years of research to tackle constructed elements to advocate for the logic masonry are extremely structurally efficient, and engineering challenges. of compression-only forms, not only because how these floor systems could be reimagined of their uniquely expressive aesthetics but also with 3D printed unreinforced concrete that Matthew DeJong because of their potential to achieve efficiency saves 70% of the material compared to typical and stability while reducing material waste. concrete floor slabs. Meanwhile, a third structure, The other project is entitled ‘Droneport’, a full- the Armadillo Vault, stretches the imagination necessities to areas that are difficult to access scale masonry shell prototype to highlight of what is possible with unreinforced dry-stone due to a lack of roads or other infrastructure. one module of the larger Droneport project construction. The vault has a minimum thickness The Droneports will be built not only to act in Africa, an initiative which seeks to create a of 5 cm, with a maximum span of approximately as small airports for the drones but also as network of drones to transport essential items 16 metres. Novel computational form-finding civic buildings, fulfilling important social to areas that lack access to roads. techniques developed by the Block Research and cultural roles in the communities. The Group enabled the geometry, while Dr DeJong ambition is that every small town in Africa and ’Beyond Bending’ – Learning from the past and PhD student Anjali Mehrotra played an in other emerging economies will have its own to design a better future important role in the engineering design Droneport by 2030. ’’Beyond Bending’ is a joint project led by through computational modelling. Construction The prototype presented at the Venice the Block Research Group at ETH Zurich in of the shell was made possible by The Escobedo Biennale is a first iteration to test the key collaboration with Professor John Ochsendorf Group, modern-day master masons based in engineering and architectural elements of such at MIT, Dr Matthew DeJong at the University Texas, USA. a building. The essential characteristic of the of Cambridge, and with The Escobedo Group. tile vault is again an efficient structural form ‘Droneport’ The exhibition takes inspiration from master to minimise materials. However, the efficient builders who have discovered expressive forms The Droneport prototype, a full-scale earthen design also enables the structure to be built through the constraints of economy, efficiency masonry shell that has been built on site, without formwork. Only fibre-glass splines and elegance, not in spite of them. For example, exemplifies one module of the future Droneport are used to guide the mason; the structure is the fan vaults of King’s College Chapel were project in Africa. The Droneport project is led self-supporting during the entire construction constructed of unreinforced stone just over by the Norman Foster Foundation, while the process, which minimises costs. 500 years ago. They span 12.7 m with complex prototype shell was designed in collaboration curvature and a minimum thickness of only with Foster + Partners, Ochsendorf, DeJong & 10 cm. Though the stone vaults are cracked in Block and the Block Research Group, ETH Zurich. places, they have stood through the centuries The shell was primarily funded by the Lafarge- without steel reinforcement. Holcim foundation. Building on this tradition, the project The project aims to create a network of R team has developed new computational tools drones to deliver medical supplies and other www.eng.cam.ac.uk/profiles/mjd97

8 University of Cambridge Department of Engineering Issue 20 Autumn 2016 , A dragonfly has a larger brain than a robber fly or a killer fly, but what are the trade-offs?

Think small Diminishing returns in

neuroscience Sam Fabian Credit: Cambridge researchers are compensating for that – for instance, if they’re more energy they require, and costs rise out chasing a target and turn their wings, another of proportion with performance. studying what makes a brain signal will be sent to turn their head, so that Engineering an optimal system efficient and how that affects the target stays in the same spot in their visual behaviour in insects – including field,” says Gonzalez-Bellido. Researchers in the Department of Engineering Gonzalez-Bellido also studies the killer are taking the reverse approach to answer the aptly named killer fly. fly, or Coenosia attenuata. These quick and questions about how the brain works so ruthless flies are about four millimetres long, efficiently by looking at systems from the top As in economics, there is a law of diminishing and will go after anything they think they can down. “If you reverse engineer an animal’s returns in neuroscience – doubling the catch – picky eaters they are not. However, behavioural strategy by asking how an animal investment going in doesn’t equal double the decision to go after their next meal is not would solve a task under specific constraints the performance coming out. With a bigger as simple as taking off after whatever tasty- and then work out the optimal solution, brain comes more available resources that can looking morsels happen to fly by. As soon as you’ll find it’s often the case that animals are be allocated to certain tasks, but everything a killer fly takes off after its potential prey, it pretty close to optimal,” says Dr Guillaume has a cost, and evolution weighs the costs exposes itself and runs the risk of becoming a Hennequin, who looks at how neurons work against the benefits in order to make the most meal for another killer fly. together to produce behaviour. efficient system. To help these predacious and cannibalistic Hennequin studies how brain circuits are “Larger brains are specialised for high flies eat (and prevent them from being eaten), wired in such a way that they become optimised performance, so there’s a definite advantage they need to fly fast and to see fast. Insects for a task: how primates such as monkeys are to being bigger and better,” says Professor see at speeds much higher than most other able to estimate the direction of a moving object, Simon Laughlin of the Department of Zoology, animals, but even for insects, killer flies and for example. “How brain circuits generate optimal whose research looks at the cellular costs dragonflies see incredibly fast, at rates as high interpretations of ambiguous information associated with various neural tasks. “But since as 360 hertz (Hz) – as a comparison, humans received from imperfect sensors is still not most animals actually have very small brains, see at around 60 Hz. known,” he says. “Coping with uncertainty is one there must also be advantages to being small.” By making the ‘pixels’ on their of the core challenges that brains must confront.” So does size matter? “When an animal is photoreceptors (the light-sensitive cells in Different animals come up with their own limited, is it because their neural system just can’t the retina) as narrow as possible, killer flies solutions. Both dragonflies and killer flies have cope? Or is it because they’re actually optimised trade sensitivity for resolution. In bright light, systems that are optimal, but optimal in their for their particular environment?” asks Dr Paloma they see better than their similar-sized prey, own ways. It’s beneficial for killer flies to be so Gonzalez-Bellido from the Department of the common fruit fly. However, the cap on small, since this gives them high manoeuvrability. Physiology, Development and Neuroscience. sensitivity and resolution imposed upon killer Dragonflies can do things that killer flies can’t, Dragonflies are among the largest flying flies by their tiny eyes means that they can but their size means they can’t turn or stop on a insects and hunt smaller insects such as only see and attack things that fly close by. dime, like a killer fly can. mosquitoes while patrolling their territories. In the early 2000s, Laughlin determined “By answering some of the questions around They have changed remarkably little in the the energy efficiency of single neurons, by efficiency in brain circuits, large or small, we may 300 million years since they evolved – most estimating the numbers of ATP molecules – the be able to understand fundamental principles likely because they are so well optimised for molecules that deliver energy in cells – used per about how brains work and how they evolved,” their particular environmental niche. “Other bit of information coded. To do this he compared says Laughlin. researchers have found that dragonflies are photoreceptors in various insects. Laughlin and capable of doing complex things like internally his colleagues found that photoreceptors are like R predicting what their body is going to do and cars – the higher the performance, the www.eng.cam.ac.uk/profiles/gjeh2

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 9 Women in Engineering An interview with Dr Jenni Sidey

Dr Jenni Sidey spoke with the Women in Engineering team about her career and her future. Since this article’s original publication, Jenni has been appointed University Lecturer in Internal Combustion Engines for the Energy Group.

How did you get into Engineering? school. I worked with two undergraduates, of sexism. In order to try and improve things, At school I was always interested in the sciences, Ester Sidebottom and Carly Brooker. Together I strive to be honest about these attitudes to particularly maths and physics. I enrolled in we organised and ran a number of local facilitate discussions on these topics. We must the Mechanical Engineering course at McGill events www.eng.cam.ac.uk/news/robogals and talk about things if we want to encourage other University and had a wonderful thermodynamics were invited to help out with the BBC Make it women to enter and stay invested in engineering instructor. I did an honours project on alternative Digital Campaign in the summer of 2015. We fields. Two years ago, I joined the Department’s energy in his lab, which stemmed into an interest ran events around the UK with the BBC team, Athena Swan Committee to try and encourage in combustion research. teaching people of all ages how to program. and participate in such discussions. Ester is now in the final year of her degree in What are you doing now and what are your the Department of Engineering and is running How have you managed to balance family plans for the future? regular Robogals events, including two family life and other interests with your career? I came to the University of Cambridge in 2011, workshops during the Cambridge Science Week. Although I’ve not yet been faced with the task working towards a PhD with Professor Nondas of balancing family responsibilities and my Mastorakos. I am now a Research Associate in What has helped your career – career, the Department has encouraged me Experimental Turbulent Combustion and Nondas fellowships, support from the Department, to pursue my outreach work and has offered acts as my Principal Investigator. I am currently inspirational teachers and colleagues? flexibility whenever I’ve needed it. applying for various academic positions, I’m fortunate to have had excellent supervisors hoping to continue a career in research and who have always been extremely supportive. Do you have any role models? teaching. Although my research takes priority, They have helped me to build a network of Absolutely – Jackie Chen is certainly a role model I’m finding that it’s important to consider the female engineers both within the Department of mine. She is a phenomenal combustion level of support offered to female academics in and in our greater field of research. Women scientist at Sandia National Labs in California. engineering at each institution I apply to. within the Department, including Professor She is confident and incredibly accomplished. Ann Dowling, have taken the time to give me What motivates you? advice about an interviews and job prospects. Do you have any advice for women I love teaching and have particularly enjoyed When I was preparing for a lecture for my first who are considering pursuing a career the outreach work I have had the privilege of academic job interview, I received an enormous in Engineering? being involved in during my time in Cambridge. amount of support and feedback from both my My advice is to seek out supportive people After the first year of my PhD, I realised that I supervisor and other professors in my division. who trust in you and your abilities, which hadn’t done much outreach work since leaving should come solely from the value of your McGill. I was encouraged by Maria Kettle, the How have you overcome challenges work. This solid backing of friends and Department’s outreach officer, and Dr Michelle and knockbacks in your career? colleagues will allow you to pursue whatever Oyen to help start Cambridge Robogals. Women are still under-represented in career you may want to achieve. Robogals is an international, not-for-profit, engineering, so without a good support student-run organisation that aims to increase network, it can be quite isolating. Although R female participation in Engineering, Science, the Engineering Department is generally very www.eng.cam.ac.uk/profiles/jams4 and Technology through fun and educational supportive I occasionally come across negative www.robogals.org initiatives aimed at girls in primary and secondary or misogynistic comments or more subtle forms www.facebook.com/CambsRobogals

10 University of Cambridge Department of Engineering Issue 20 Autumn 2016 Women in engineering celebrated with inaugural competition

The Inspirational Women Engineers competition celebrating women in the field was held at the Department of Engineering. The winners were announced at an event during a lunchtime champagne reception.

The competition was run by the Athena wrote the code which enabled humans to Swan team in order to raise awareness of the land on the moon. Through her scientific The quality of entries many amazing women engineers, past and papers and the work of the company she was excellent,“ and with present, and to help inspire others to pursue later founded she also made important study and careers in engineering. Nearly all contributions to ideas about fault-tolerance so many interesting stories the engineering portraits that hang around and reliability. the judging panel found their the Department of Engineering are of male Vere, an undergraduate engineer in the task very difficult. engineers; displaying the winning entries will Department, was presented with his prize help to redress the balance and counteract the of an iPad by Professor Dame Ann Dowling, To complement the competition posters ‘stereotype threat’ effect for the many women who also presented gift tokens for chocolate we are currently seeking profiles of women now studying and working in the department. to the twenty runners up. Dame Ann, former engineers (staff, students and alumna) of The competition attracted 60 nominations Head of Department and Professor in the the Department, to inspire potential women of women from all over the world and all Energy, Fluid Mechanics and Turbomachinery applicants by showing that women are engineering disciplines – from over 2000 years division, now serves as President of the Royal forging successful paths in all branches of ago up to the very current achievements of Academy of Engineering. engineering and at every level. If you are Department of Engineering alumna Ruth The winning and shortlisted entries interested in providing a profile (see the link Buscombe. Ineligible for nomination were (a short bio, a photo of the engineer below) or wish to know more, please email women currently working or studying in the and the reasons for nominating them) have Madeline McKerchar at [email protected]. department, as this would have made judging been produced as posters and are on display an impossible task. in the Engineering Library. After the initial www-womeninengineering.eng.cam.ac.uk/ The quality of entries was excellent, display, the posters will be framed and shown inspiring/index and with so many interesting stories the around the Department’s various buildings. judging panel found their task very difficult. The 60 total entries have also been bound After some discussion, first prize was awarded together in a booklet which is available at the to Vere Whittome for his nomination of link below. R Margaret Hamilton. There is already interest in running the The booklet of entries is available online at Using one of the first chip-based computers competition again, and the hope is this will www-womeninengineering.eng.cam.ac.uk/ with only 64k of memory, Margaret successfully become an annual event. news/compbooklet

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 11 Institute for Manufacturing Design Show 2016

The Manufacturing Engineering Tripos (MET) provides engineering students with the management competence, business acumen and interpersonal and organisational skills they need to become world-class leaders.

Over the last year, teams of three or four MET students have completed a major design project to develop a new product with real business potential. Having first identified a customer need, they have researched the market, developed original design concepts and created a full business plan. The projects have generated some exciting new ideas and innovative technology.

BrekTech Wafflestation The BrekTech Wafflestation is a revolutionary continuous flow waffle production device for commercial use, with potential industrial scalability options. Aimed at small to medium-scale commercial catering, the Wafflestation enables a less laborious continuous approach to waffle production. The n Bottle Brick team identified an opportunity to challenge AdaptaMould the existing standards of the traditional waffle travelling on top of the wall. This allows it iron that is currently used for both home and AdaptaMould is an innovative way to to be cheaper, lighter and more compact. mass production – and introduce an automated rapidly create moulds for use in vacuum In the UK, there is expected to be a shortage solution for smaller firms that would not have forming. The system uses a series of pins, of 244,000 brick layers by 2020. In Australia, the previously considered this approach. electro-mechanically controlled to create shortage has driven up the cost of labour to the desired shape. The Wafflestation’s core competency revolves an average of $100,000 a year. Using BRICK-E around its two counter rotating silicon belts. 3D printing is bringing rapid prototyping to the to replace a skilled worker with an unskilled The belts both support and shape the batter mass market. Vacuum forming, where a sheet of worker, even at current wages, will result in throughout the cooking process. Batter heated plastic is pulled down over a mould and substantial cost-savings. is dispensed from a hopper at a carefully then a vacuum applied to produce a shaped The robot will lay both cement and bricks controlled rate before being conveyed plastic piece is not as quick or easy as 3D printing. requiring the worker to simply perform a set through the heating chamber. The process of creating the mould can take up up and feed supplies. At a length of 80cm and to a week, as they are normally made from wood weighing less than 25kg, a single worker can and require careful sanding to make the correct position BRICK-E with ease. By using a unique Crispeasy shape. The team aimed to greatly increase the spacing structure, BRICK-E is able to bypass the Crispeasy is a compact appliance that speed of this process. traditional constraints on build speed imposed produces delicious spiral potato crisps in the The concept of AdaptaMould is to feed a CAD by cement drying. Carrying the load through comfort of your own home. The powerful model into our product, which will then create a the spacers rather than the cement, a given oven and automated slicing system make vacuum forming mould within minutes. construction project can progress at a rate much baking crisps easier than ever. beyond the typical 6 rows per day. As such, not only will it be cheaper, but also faster than relying Crispeasy offers a fast and simple solution. The on traditional work methods. machine uses an automated slicing system BRICK-E that cuts half a potato at a time into a spiral. BRICK-E is a robot designed to reduce The spiral then moves into a powerful oven the skilled labour requirement in brick powered by four heating elements, which laying. With this semi-automated device, PolyPack allows the process to be completed in under unskilled workers can construct brick walls PolyPack is an innovative solution 15 minutes. The oven also contains a pump- autonomously at low cost. Unlike existing to creating beautiful, sturdy and powered oiling system that aims to balance the brick laying robots, BRICK-E completes all environmentally sustainable packaging. healthiness and crispiness of the snack. tasks required to build a straight wall by The packaging consists of a soft fibrous

12 University of Cambridge Department of Engineering Issue 20 Autumn 2016 quality goes down. Upcycling is a popular new Fruiticle concept employed by Paperbot to make a Fruiticle manufactures customisable icicles valuable and lasting product by reusing paper to be used as drinks coolers in high-end without having to break down the fibres again. cocktail bars. The Paperbot machine begins with a hopper The user can create straight or ‘wavy’ icicles from of paper and a reservoir of glue. Using a motor, a piece of fruit at its core, and place the icicle gravity glue is applied to the paper and dropped directly into the customer’s glass. The cocktail on to a mould. An innovative positioning system market is predicted to grow by 50% between is at the heart of the system that moves the glue 2013 and 2017, and is being guided by the feeder back and forth along the mould. desire for cocktails to be ‘instagrammable’, n BRICK-E with cocktail bars focusing more attention on presentation. The product is automatic, self- Bottle Brick contained, and easy to use. It consists of two Bottle Brick – a small-scale community PET conjoined units: a freezer section where the bottle recycling solution. It recycles and icicles are grown, and a fridge section where reforms waste plastic bottles into building the water is kept cool. The skewered fruit is bricks for the developing world, eliminating placed in the freezer across a rack, which can be use of concrete and reducing landfill waste. rotated to create curves in the growing icicles. The rotation is controlled by a stepper motor Bottle Brick introduces a novel process of in a pre-programmed cycle. Water for the icicle reforming a waste PET drinks bottle into a is delivered via a feed system designed for the stackable, interlocking, tessellating shape optimum drip rate for icicle formation. which may be used as a structural brick. The PolyPack n team identified an existing practice in some developing countries such as Nicaragua interior transitioning to a hard plastic shell Rotoform and Nigeria whereby bottles are removed to provide twofold protection. from local landfill sites, filled with mud and Rotoform uses an innovative rotational moulding machine to produce hollow PolyPack currently uses shredded PET – sourced stacked as building blocks, held together fibreboard products from a sawdust from plastic bottles – as a raw material with with mortar. The result is a robust housing mixture. Rotational moulding is widely used which to create this pioneering packaging structure. Having seen this they questioned in plastic manufacturing, with the ability product, but could potentially use other plastics. how the process might be improved. The team set themselves the challenge of making this to form thin hollow products allowing The method involves two processes to production process cheaper, easier and even lightweight and novel designs. The team has transform shredded PET to fibres to packaging. more environmentally friendly. The existing adapted this technology, using an original The initial process – inspired by candy floss ‘bottle wall’ requires at least 25% concrete machine to maximise spinning speeds. machines – heats a spinning bowl and softens in volume. Not only is concrete expensive, Combining this capability with the use of the shredded plastic to be forced through it is non-renewable, non-recyclable and its sawdust allows Rotoform to produce a similar a row of holes. This creates fibres that offer manufacture contributes to 5% of global CO range of fantastic products but using eco- impact resistance and thermal insulation. The 2 emissions. And so we sought to minimise or friendly fibreboard materials. Using sawdust is secondary process involves filling a heated eliminate the use of concrete. part of what makes Rotoform unique. Sawdust mould with the candyfloss like material. With is a waste material – 0.4 million tonnes are careful control of process parameters a hard The team have developed a vessel for the produced and disposed of every year. Rotoform outer shell is produced with an optimum process of heating and blow moulding a takes this sawdust and enables the production thickness to balance the requirements of bottle at 14 bar through manual labour with of eco-friendly products. Achieving the rotational structural rigidity and finish against those of the use of a bicycle pump and then cooling speeds necessary to use the viscous sawdust efficient material use and interior cushioning. the bottle. The output is a well-defined, intricate brick which successfully stacks in a mixtures was the most significant challenge the honeycomb formation, significantly reducing team had to overcome. Traditional rotational Paperbot the required volume of concrete. The working moulding machines reach rotational speeds of 60 rpm. Rotoform has designed a more rigid Paperbot is a unique new take on the prototype successfully provides ‘proof of machine, which employs powerful motors paper mache formula. It aims to layer concept’ and is designed to be easily scalable allowing stable, high speed rotation. newspaper and glue on a rotating mould in order to produce bottles in larger quantities. to build up a product, such as a lampshade. The rate of production of one bottle is 6 Development of the optimal mixture required Paper mache is usually a messy and time minutes. Scaling to 10 units would allow a rate lengthy testing, but the ideal ratios of fibres, consuming process, but with this machine of production of 100 bottles per hour. PVA and water were finally found. This allowed the process can be dramatically improved, The organisation would be run as a not-for- the team to minimise drying times and particularly for large scales. profit social enterprise, distributing this product maximise the strength of the fibreboard. Paper has been around for over 2000 years and through existing charitable organisations to is amazing material but it consumes trees that areas which may benefit from this practice. R Demonstration videos of all of the 2016 we cannot afford to lose. So we must recycle To our knowledge there is currently no other Design Show projects can be found on the it but, unfortunately, after 4-6 times the fibres company which recycles bottles by directly re- Department’s YouTube channel: become too short or weak and the paper blow-moulding them. www.eng.cam.ac.uk/Youtube

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 13 , Visualisation of Silicon Microgravity’s sensing technology in a borehole

Cambridge spin- out secures $3m to improve oil recovery efficiency

Silicon MicroGravity (SMG), a newly-formed University of Cambridge spin-out that has developed a novel sensor technology used by oil companies to enhance oil recovery, has received initial funding of $3 million from Imperial Innovations Group plc (AIM: IVO, ‘Innovations’) and Cambridge Enterprise, the commercialisation arm of the University of Cambridge, together with grant funding from the UK Government.

SMG’s sensors, developed in partnership the Institution of Mechanical Engineers’ with BP, are sensitive enough to measure one Stephenson Fund, a private investor, billionth the level of Earth’s gravity and are InnovateUK and the Natural Environment We are delighted“ that Dr Seshia’s small and robust enough to be sent deep into Research Council (NERC), which have awarded unique technology is being boreholes to distinguish oil from water. a substantial grant. commercialised by SMG. We Once the position of water is established SMG’s advisory board includes Kevin Dodds, are very excited by the market and tracked, reservoir engineers can mitigate General Manager of ANLEC in Australia, and opportunity and we are keen the potentially damaging results of water Professor Roger Howe from Stanford University. to support future progress. reaching a production well. SMG estimates Dr Ashwin Seshia, co-founder of Silicon that the technology could improve yields on Microgravity, said: “The SMG devices advance Julian Peck conventional reservoirs by up to 2 percent, the frontiers of gravity sensor technology representing significant increases in production building upon several years of University and revenues. research and innovation. SMG brings together water is within a reservoir and enable us to A team of Cambridge scientists, led a leading international team of experts take mitigating action. This collaboration by Dr Ashwin Seshia of the Department of to address the next phase of technology fits perfectly with BP Ventures’ strategy of Engineering, has been working closely with BP translation and we are looking forward to investing in new technologies that can be to develop the sensors. working collaboratively with our partners to rapidly field tested and deployed.” Design work began in 2010 and has deploy these tools widely.” Stephen Tetlow MBE, Chief Executive of resulted in several generations of prototypes Paul Vickery, Chairman and co-founder the Institution of Mechanical Engineers, said: providing experimental validation of the of Silicon Microgravity, said: “I am very “We are excited to be supporting such an underlying device approach. A successful test excited to form this new company based exciting and cutting-edge technology. The of the technology was conducted in 2012 on a long standing collaboration between Institution’s Stephenson Fund aims to fulfil prompting BP to fund a follow-on project to Cambridge University and BP. We have created the Institution’s original purpose to give an address further optimisation and pursue large- a compelling business plan, raised a sizable impulse to invention and also help companies scale manufacture of the sensors. SMG was initial investment and formed a credible overcome the investment hurdle between formed in 2014 to accelerate the development global team to launch the company. I look Research and Development and bringing a of the product and develop a service that forward to building a business that can help product to market. can capture and analyse data on behalf of oil oil companies enhance oil recovery from their “This innovation could revolutionise oil well companies. The first field trial in a production major assets.” recovery and is an example of exactly the sort well is scheduled for 2017. Akira Kirton from BP Ventures said: “Water of innovation we are committed to supporting.” Innovations led the funding round management is an increasingly important alongside Cambridge Enterprise, which also issue for BP and the whole industry, so we invested and licensed the technology to are excited about the potential for SMG’s R SMG. SMG is also being supported through technology to help us pinpoint where www.eng.cam.ac.uk/profiles/aas41

14 University of Cambridge Department of Engineering Issue 20 Autumn 2016 ALUMNI UPDATE Alumna Anya Jones Receives Presidential Early Career Award

President Barack Obama has named alumna Anya Jones a recipient of the Presidential Early Career Award for Scientists and Engineers (PECASE), the highest honour bestowed by the US Government on science and engineering professionals in the early stages of their independent research careers.

“These early-career scientists are leading the hired straight into a tenure-track post at the way in our efforts to confront and understand University of Maryland despite having no post- These early-career scientists are challenges from climate change to our health doctoral experience. This is very rare, but their leading the “way in our efforts and wellness,” President Obama said “We confidence was confirmed by her subsequent congratulate these accomplished individuals success in generating new grants and prizes. to confront and understand and encourage them to continue to serve “All of the above is even more remarkable challenges from climate change as an example of the incredible promise and when one considers that Anya is also a double to our health and wellness. ingenuity of the American people.” blue. She first represented Cambridge in President Obama Anya, whose PECASE nomination was fencing and was part of the 2010 blue boat. sponsored by the US Department of Defense, In my experience it is exceptionally rare for has been a member of the Aerospace anyone to be able to row at the standard Engineering faculty at the University of needed to make the boat race and do a PhD in successful scientific career, and look forward to Maryland since 2010. She earned her Engineering. If she hadn’t told me I would have continuing to work with them in the future.” doctorate in experimental aerodynamics from never even noticed that she was in the squad She received the National Science the University of Cambridge, her Master of – it never affected her work in any way.” Foundation Faculty Early Career Development Science in aeronautics and astronautics from Darryll J. Pines, Clark School Dean and (CAREER) program award for research to the Massachusetts Institute of Technology, Nariman Farvardin Professor of Engineering improve the safety, reliability, and efficiency of and a dual bachelor’s degree from Rensselaer said “Dr. Jones’ unmistakable leadership in our air vehicles by gaining a deeper understanding Polytechnic Institute in aeronautical and field so early in her career gives me great hope of the physics of the large flow field mechanical engineering. for the future of engineering and our country.” disturbances encountered in high winds and Speaking about Anya, her supervisor here Anya is chair of a NATO Research gusty flight environments. at the Department of Engineering Professor Technology Organization task group on gust Anya has developed unique Holger Babinsky, said “Anya, first came to know response and unsteady aerodynamics and experimental capabilities at the University of the Department when she was involved, as an associate fellow of the American Institute of Maryland to allow for the exploration of a Masters student at MIT, in the Silent Aircraft of Aeronautics and Astronautics (AIAA). She the interaction between a wing and a large, Initiative. She came to know us from the also serves as a member of the AIAA Applied well-characterized gust in a repeatable various team meetings and decided to pursue Aerodynamics Technical Committee, the and controlled environment. By modeling a PhD here. University of Maryland Energy Research Center, this interaction both experimentally and ”Anya worked on an experimental and the Maryland Robotics Center, is a faculty analytically, her research offers a new approach investigation into flapping wing aerodynamics. advisor to the UMD Women in Aeronautics to validating classical aerodynamic theories This research was part of a wider NATO effort and Astronautics, and serves on the Raising and a new framework for physics-based to better understand how small birds and Excitement for Science Engineering and models of separated flow. insects can produce the necessary force Technology (RESET) board of directors. The PECASE awards, established by to keep flying. Anya designed and built a Speaking about her time here at President Clinton in 1996, are coordinated by completely new experiment in our water Cambridge Anya said, “My PhD studies at the the Office of Science and Technology Policy tunnel which has since been copied by many Department of Engineering were an enjoyable within the Executive Office of the President. other research groups around the world. One and fulfilling experience throughout. The Awardees are selected for their pursuit of of her papers was at one point in the top research I began at the Department formed the innovative research at the frontiers of science three most cited articles in a major journal: foundation for much of my current work and and technology and their commitment to ‘Experiments in Fluids’. Her PhD research was for this recent award. I am exceptionally grateful community service as demonstrated through a stunning success, it led to a follow-on NATO to the Department of Engineering, Holger, scientific leadership, public education, or research effort (which used Anya’s work as a and all of my colleagues at Cambridge who community outreach. starting point) and rather unusually she was were instrumental in setting me on a path to a

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 15 Professor Sir David MacKay 1967–2016

We are saddened by the loss of Professor Sir David MacKay, Regius Professor of Engineering, who lost his battle against stomach cancer on 14th April 2016. He was 48 years old.

As a scientist, he made contributions to a His commitment to science outreach and to the government he returned to Cambridge wide range of fields, including metallurgy, his long-standing interest in the environment in 2013 as the inaugural Regius Professor of information theory, machine learning, human- resulted in the book Sustainable Energy – Engineering in the Department of Engineering. computer interaction and sustainable energy. Without the Hot Air (2009). The book achieved He was a Fellow of the Royal Society, His fundamental contributions to information widespread acclaim – The Economist described the Institute of Physics, the Institution theory and machine learning include the it as a tour de force, and it was favourably of Civil Engineers, and Darwin College, development of Bayesian methods for artificial reviewed in Science, The Guardian, and many Cambridge. In 2012 he was elected Honorary neural networks. His detailed book Information other newspapers, specialist journals and Fellow of Trinity College, Cambridge. He was Theory, Inference, and Learning Algorithms (2003) blogs. As with his previous book, Sustainable knighted in the 2016 New Year Honours for his was an instant classic and is still widely read Energy was released for free on the web. Nine services to scientific advice in government and in the field. He believed in open access at an months after the publication of Sustainable science outreach. early stage and as a consequence his book has Energy he was appointed Chief Scientific His battle against cancer was bravely always been available for free on his website. Adviser in the Department of Energy and chronicled on his blog. The range of his He cared deeply about education. Climate Change (DECC) for a five-year term. world-leading research was remarkable and He taught mathematics at the African Institute At DECC he and his colleagues developed the were it not for his early death he would surely for Mathematical Sciences in Cape Town, South 2050 Energy Calculator, which was released as continued to have had, a strongly positive Africa and he was a popular lecturer at the free software and has been adapted by several influence on both academic research and Department of Physics where for many years other countries. public policy for several decades. We will he taught dynamics, computing, information David read Natural Sciences at Trinity remember him as an intelligent, principled, theory, pattern recognition and neural College, Cambridge, and received his PhD from enthusiastic and engaging colleague who left networks, and materials, electronics, California Institute of Technology for his work us with an inspiring legacy. He is survived by and renewable energy. in Professor John Hopfield’s research group on his wife Ramesh and their two young children, His passion for information theory, Computation and Neural Systems. After his PhD Torrin and Eriska. education and outreach lead to the invention he was the Royal Society Smithson Research David MacKay, born 22 April 1967, died 14 of Dasher, an information-efficient text entry Fellow at Darwin College, where he was later April 2016. method for people with disabilities, which elected Official Fellow. He was a Lecturer, allows users to communicate with any Reader and Professor of Natural Philosophy at muscle. Dasher is free software and currently the Department of Physics where he started R maintained by volunteers at Google. and led the Inference Group. After his service itila.blogspot.co.uk/

16 University of Cambridge Department of Engineering Issue 20 Autumn 2016 Hackathon unleashes the power of wearables

The Cambridge University Engineering Society (CUES) has held its first-ever Hackathon. Organised in collaboration with ARM, participants had the opportunity to use ARM microcontrollers, sensors and other products in the mbed system to design their creations. The event drew in more than 100 students not only from engineering but from many disciplines across the University.

The theme of the Hackathon was wearables. • Childcare, a set of bracelets for children and Teams were instructed to develop an their parents that buzz if a child gets too far, It really engages enthusiastic electronic wearable product within 24 hours alerting the parents students and“ gets them into that uses the ARM mbed platform. • Sygnal, a bracelet that provides information First prize went to Tomas Cerskus, Quang electronics and programming. (such as the time) via vibration without Ha and Josiah Yan for their Rowbot Personalised you having to check your watch or retrieve Leo Zhu Rowing Device. They developed a miniature your mobile wireless device that attaches near the rower’s wrist and streams real-time acceleration data to • Panic Button, a small button you press when a mobile phone. The device can both analyze you’re feeling unsafe that alerts nearby data by itself and give personalized advice, or Facebook friends to alert them of the danger Technology for Development Make-a-thon, can be used by the team coach to track the which encouraged students to solve design • Slipper Alarm Clock, an alarm clock performance of the team. problems from international development embedded within a pair of slippers that only The second-place team built what they and humanitarian contexts. Interdisciplinary shuts off when the user puts the slippers on. called Internet of Decks – lights that can be undergraduate teams competed over five attached to clothes which beat in time to music. days using open-source technologies to learn, “I would like to see more such events, both Team members George Fortune, Agnes Cameron explore and innovate through challenges put as an ex-student and an ARM employee,” said and Jamie Wood embedded light-emitting forward by the Centre for Global Equality. Leo Zhou, one of the ARM engineers who diode strips in a dress that flash in a range of assisted with the Hackathon. “It really engages patterns based on signals from a beacon and an enthusiastic students and gets them into app that users download to their phones. electronics and programming.” Students also participated in similar Other creations included design challenges at the Open Technology • Smart Bin, a waste bin with flex sensors to Week which took taking place in the R measure weight and light sensors that detect Department of Engineering’s James Dyson developer.mbed.org/blog/entry/CUES- when the bin is full Building 9–15 June. It included the Open Hackathon-Wrap-Up

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 17 Consortium scores €9 million for textile nanofibre research

The Department of Engineering will coordinate a new €9 million European Commission-funded project on technical textiles.

The fibre-based materials for non-clothing applications consortium involves 14 partners from the UK and Europe in a 4-year innovation action activity with the purpose to mature technologies from a technology validated in a lab to a technology demonstrated in a relevant environment. The project is founded upon previous research activities and demonstrated proof of concepts and laboratory prototypes of fibre electronic components. These include fibre-stretchable electrodes and conducting fibres, fibre-light emitting devices, fibre-field effect transistors and silicon embedding fibres, fibre-piezo harvesters, fibre-sensors, Christoph Meier Credit: and fibre-energy storage. The activities have been incubated for almost a decade in Europe, Korea and the UK. A pioneering team of techniques, in order to make circuits and n Nanofibre mesh scientists who initiated the work at Samsung multifunctional systems that are intrinsically Advanced Innovation Technologies (SAIT) are flexible and stretchable.” now part of the consortium, including the Dr Occhipinti is a member of the I have seen this field evolving coordinator of 1D-NEON project and Professor Department of Engineering and is also the in the last decade“ and feel that of Electrical Engineering Jong Min Kim. National Outreach Manager of the EPSRC Professor Kim said: “I have seen this field Centre for Innovative Manufacturing in Large- timing is opportune to bring evolving in the last decade and feel that timing Area Electronics. this wonderful innovation to the is opportune to bring this wonderful innovation Professor Arokia Nathan, a work-package market and to the community. to the market and to the community. I have leader in 1D-NEON for Design and Modelling, Jong Min Kim the privilege to lead this unique consortium said: “This project represents a stepping stone which is poised to revolutionise electronics to bring further innovation on e-textiles for the manufacturing and bring added value to the University of Cambridge and the UK. We are field of technical textiles.” looking to establish a strong network in the frequency wireless communications pertinent Professor Kim is Professor of Electrical UK to support the field and work with other to wearable systems. The laboratory has world- Engineering in the Department. Prior to his centres of excellence in the UK and with the leading expertise in systems integration and arrival at Cambridge, he was Professor at textile industry to provide the UK with yet has pioneered many important areas related Oxford University and Senior Vice President another opportunity to become world leader to circuits and systems and computer-aided of Samsung Electronics and SAIT in charge of in the field of e-textiles for smart wearables. We design, including compensation of materials leading innovations including organic light- look forward to creating a Future Manufacturing deficiencies by electronics. emitting diode and quantum dot displays, Hub in Fibre Electronics in the UK and towards a “The key objective of a Future fibre electronics and graphene technologies. global centre of excellence in textiles, together Manufacturing Research Hub in this area will Dr Luigi G. Occhipinti, Exploitation with the combined effort of the University of be to create a bridge between the electronics and Business Development Manager and Manchester and other academic and industrial and textile industries and help build UK work-package leader for Exploitation and research centres active in the UK.” leadership in this multidisciplinary field by Dissemination, said: “The 1D-NEON project Professor Nathan holds the Chair of developing new added value products such represents a unique opportunity to bring Photonic Systems and Displays in the as stretchable, wearable and cloud-connected innovation in technical textiles by embedding Department of Engineering. He leads a multi- smart textiles,” said Brian J. McCarthy, who electronic, sensing and energy functionalities disciplinary research group whose primary leads the Knowledge Transfer Network on into active fibres. The new manufacturing focus is on the heterogeneous integration Textiles in the UK. platform will use processes widely adopted by of materials and processes, sensors, energy the textile industry, from multi-layered fibre harvesting and storage devices including R extrusion to weaving, knitting or braiding wireless power, signal processing and radio 1d-neon.eu

18 University of Cambridge Department of Engineering Issue 20 Autumn 2016 Trimble partnership will advance engineering and construction technologies

The Department’s Construction Information Technology Laboratory, part of the Laing O’Rourke Centre for Construction Engineering and Technology, will partner with California-based technology firm Trimble to collaborate on research to advance technology development in the engineering and construction industries.

Trimble’s contribution includes a sponsorship Fosburgh, sector vice president at Trimble. programme which will focus initially on “Working closely with the research teams at This exciting new partnership Cambridge, our goal is to foster innovation • conducting research to potentially with Trimble“ will enable us and enable academic research in information improve safety, reduce costs and increase to work together to push predictability and operational efficiency technologies that can affect and transform the forward our agenda to develop across the construction sector way the industry designs, builds and operates buildings and infrastructure.” new, transformative tools and • providing educational and professional Professor Campbell Middleton, Head of the technologies to deliver a much development to encourage and champion Laing O’Rourke Centre, said, “The construction safer and more productive construction information technology sector is undergoing rapid transformation as a construction industry and help research in academia and industry result of the revolution in digital engineering. build the infrastructure on which • accelerating the advantages of building Cambridge University has a wide portfolio of the wellbeing of society depends. information modelling and the use of computer research projects which aim to solve problems vision and augmented reality technologies to in the construction sector. This exciting new Campbell Middleton simplify many common construction problems partnership with Trimble will enable us to in practical applications. work together to push forward our agenda to develop new, transformative tools and “The research interests between the University technologies to deliver a much safer and more of Cambridge Construction Information productive construction industry and help Technology Laboratory in the Laing O’Rourke build the infrastructure on which the well- R Centre and Trimble are truly aligned,” said Bryn being of society depends.” www.construction.cam.ac.uk

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 19 Professor Hugh Spikes FREng, Imperial Hugh Spikes FREng, London College Professor Credit:

50 years of tribology – or should it be 523?

Tribology, the science of friction, lubrication – modifying or coating a surface in order, for n Thin lubricant films play an important role in reducing and wear, is a key enabling technology that example, to achieve lower friction or greater friction and wear. Here coloured interference fringes is involved in nearly all mechanical systems. wear resistance. Aero-engines, road vehicles outline the circular contact patch, 270 µm in diameter, 2016 has marked a milestone for the subject, and railways, artificial hip and knee joints, in the oil film between a steel ball and a flat surface. being the 50th anniversary of the word computer hard disk drives and toothbrushes ‘tribology’ which was celebrated with several all benefit from the pervasive underpinning events including a reception at Buckingham science of tribology, and Ian argues that has shown for the first time that Leonardo’s Palace. Ian Hutchings, GKN Professor of the essential elements of tribological studies of friction extended over more than Manufacturing Engineering at Cambridge, has understanding should lie at the core of the 20 years, and that even with his limited written an article for the Royal Academy of education of every engineer. For more than understanding of mathematics and mechanics Engineering’s magazine Ingenia that highlights 20 years, he and John Williams have run an he incorporated his empirical knowledge of the achievements we have made over the past annual short course on the subject for industry friction into models for several mechanical 50 years. that regularly attracts 30-40 delegates from all systems. Although his work had no influence The Cambridge connection to the subject over the world. on the development of the subject over the dates back to the key work of Philip Bowden We have known for a long time that succeeding centuries, Leonardo da Vinci holds and David Tabor from the 1940s to the 1980s Leonardo da Vinci made the first quantitative a unique position as a pioneer in tribology. (though Bowden died in 1968), initially as part studies of friction about 500 years ago. But of the Department of Physical Chemistry, and it was only after a detailed chronological then in the Cavendish Laboratory. Within the study of his notebooks, also carried out by Department of Engineering very important work Ian Hutchings, that we can now identify was done by Ken Johnson (who died last year) Leonardo’s very first statement of the laws and Jim Greenwood (now Emeritus Reader). of friction. In an article which has received Advances in tribology have demanded a lot of publicity, Ian has shown that a tiny the skills of mechanical engineers, materials page in a notebook preserved in the Victoria R scientists, physicists and chemists, and have and Albert Museum in London contains www.ingenia.org.uk/Ingenia/Articles/1009 www.eng.cam.ac.uk/news/leonardo-da-vinci- underpinned much of the world’s engineering the very first record of these key findings, first-systematic-study-friction progress. Tribology is very often associated expressed in both words and drawings with bearing design, but its reach extends to in 1493. Interestingly, the page had been Ian Hutchings discusses all aspects of modern technology in which commented on much earlier by art historians his discovery of surfaces move against each other, even who were interested in a sketch of a woman’s Leonardo da Vinci’s friction studies to apparently surprising areas such as hair head; the material on friction below it on conditioners and cosmetics. Many would the same page was referred to as ‘irrelevant also include the field of surface engineering notes and diagrams in red chalk’. Ian’s work

20 University of Cambridge Department of Engineering Issue 20 Autumn 2016 w

Smart glass goes from clear to opaque and back again – 27 million times

A smart material that switches back and forth between transparent and opaque could be installed in buildings or automobiles, potentially reducing energy bills by avoiding the need for costly air conditioning.

Imagine a glass skyscraper in which all of the which is different from a solid crystal or a liquid. a ‘sunroof’ in a car that could be switched back windows could go from clear to opaque at the The simplest definition of a crystal is a solid and forth between transparent and opaque. flick of a switch, allowing occupants to regulate in which the atoms form a distinct spatial order. The work has been patented, and is being the amount of sunlight coming through the A liquid crystal, such as those that are used in commercialised by Cambridge Enterprise, the windows without having to rely on costly air many televisions, flows like a liquid, but has University’s commercialisation arm, with a conditioning or other artificial methods of some order in its arrangements of molecules. major industrial partner through a technology temperature control. The liquid crystals used in televisions are known framework transfer agreement. Researchers in the Department have as nematic crystals, where the molecules The original motivation behind the developed a type of ‘smart’ glass that switches are lined up in the same direction, but are development of smectic A was to develop a back and forth between transparent and otherwise randomly arranged. type of low-power electronic signage, of the opaque, while using very low amounts of In a smectic liquid crystal, the molecules type commonly seen at bus stops, that would energy. The material, known as smectic A have a similar directional ordering, but they are use low amounts of energy, and would not composites, could be used in buildings, also arranged in stacked layers which confines fade in bright sunlight. automotive or display applications. the movement of ionic additives. When a The original form of smectic A was based Working with industrial partners including voltage is applied, the liquid crystal molecules on organic materials, but the newer version Dow Corning, the Cambridge researchers have all try to align themselves with the electric is silicon-based. One sample of smectic A in a been developing smectic A composites over field, and the material they are embedded in lab at CAPE has been switched back and forth the past two decades. The team, based at the (glass or plastic) will appear transparent. between opaque and transparent more than Department’s Centre for Advanced Photonics When the direction of the voltage is slowly 27 million times, switching once per second and Electronics (CAPE), has made samples changed, the ionic additives disrupt the layer for several years. of smectic A based glass, and is also able to structure of the smectic liquid crystals, which “The earlier glass-based samples we produce it on a roll-to-roll process so that it has the result of making the glass or plastic produced worked well, but there was a can be printed onto plastic. It can be switched panel appear milky. Increasing the frequency challenge in making them in sizes larger than a back and forth from transparent to opaque of the voltage causes the movement of the metre square,” said Chu. “So we started making millions of times, and can be kept in either ionic additives to freeze out and then switches it in plastic, which meant we could make bigger state for as long as the user wants. the plastic or glass panel back to transparent. samples, and attach it to things like windows “In addition to going back and forth These transitions happen in a fraction of a in order to retrofit them. This would reduce the between clear and opaque, we can also do second, and when the voltage is switched off, effects of solar radiation, since the energy is different levels of opacity, so for example, the material will remain either transparent or being scattered rather than absorbed.” you could have smart windows in an office opaque until the user wants it to switch again, Chu’s team is also working on other building that automatically became more meaning that unless the material is actively possible applications for smectic A and related or less opaque, depending on the amount switching states, it requires no power. technologies, including the possibility of a of sunlight coming through,” said Professor Possible applications for smectic A transparent heat controllable window and non- Daping Chu, one of the developers of smectic composites include uses in the construction, intrusive public information messaging system. A technology. advertising and automotive industries. For The main component of the developed example, it could be applied to glass buildings composite material is made up of a type of in order to regulate the amount of sunlight R liquid crystal known as a ‘smectic’ liquid crystal, that could get through, or it could be used as www.eng.cam.ac.uk/profiles/dpc31

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 21 UK steel can survive if it transforms itself, say researchers

A new report claims that British steel could be saved, if the industry is willing to transform itself.

The report, by Professor Julian Allwood, argues of date. The quality of recycled steel is generally costs. If the existing operations are to be sold, that in order to survive, the UK steel industry low, due to poor control of its composition. taxpayers must subsidise the purchase without needs to refocus itself on steel recycling and Because of this, old steel is generally ‘down- the guarantee of a long term national gain. If on producing products for end users. He cycled’ to the lowest value steel application the plants are closed, the loss of tax income argues that instead of viewing Tata Steel’s UK – reinforcing bar. According to Allwood, the and payment of benefits will cost taxpayers exit as a catastrophe, it can instead be viewed UK’s strengths in materials innovation could be £300m-£800m per year, depending on knock- as an opportunity. applied to instead ‘up-cycle’ old steel to today’s on job losses. Allwood’s report, A bright future for UK steel: high-tech compositions. Allwood’s strategy requires taxpayers A strategy for innovation and leadership through According to Allwood, today’s global to invest in a transformation, for example up-cycling and integration, uses evidence steel industry has more capacity for making through the provision of a long term loan. gathered from over six years of applied steel from iron ore than it will ever need This would allow UK to innovate more than research by 15 researchers, funded by the UK’s again. On average, products made with steel any other large player, with the potential of Engineering and Physical Sciences Research last 35-40 years, and around 90% of all old leadership in a global market that is certain to Council (EPSRC) and industrial partners steel is collected. It is likely that, despite the triple in size. spanning the global steel supply chain. current downturn, global demand for steel will He singles out the example of the Danish “Tata Steel is pulling out of the UK, for continue to grow, but all future growth can be government’s Wind Power Programme, good reason, and there are few if any willing met by recycling our existing stock of steel. “We initiated in 1976, which provided a range of buyers,” said Allwood, from Cambridge’s will never need more capacity for making steel subsidies and support for Denmark’s nascent Department of Engineering. “Despite the sale from iron ore than we have today,” said Allwood. wind industry, allowing it to establish a of the Scunthorpe plant announced earlier Apart from the issue of recycling, today’s world-leading position in a growing market. this week, the UK steel industry is in grave UK steel industry focuses on products such as Allwood believes a similar initiative by the UK jeopardy, and it appears that UK taxpayers plates, bars and coils of strip, all of which have government could mirror this success and must either subsidise a purchase, or accept low profit margins. “The steel industry fails to transform the steel industry. “Rapid action now closure and job losses. capture the value and innovation potential to initiate working groups on the materials “However, we believe that there is a third from making final components,” said Allwood. technologies, business model innovations, option, which would allow a transformation of “As a result, more than a quarter of all steel is financing and management of the proposed the UK’s steel industry.” cut off during fabrication and never enters a transformation could convert this vision to a Instead of producing new steel, one option product, and most products use at least a third plan for action before the decision for plant for the UK steel industry is to refocus itself more steel than actually required. The makers closure or subsidised sale is finalised,” he said. toward recycling steel rather than producing of liquid steel could instead connect directly to “This is worth taking a real shot on.” it from scratch. The global market for steel final customer requirements.” recycling is projected to grow at least three- These two opportunities create the scope fold in the next 30 years, but despite the fact for a transformation of the steel industry in R that more than 90% of steel is recycled, the the UK, says the report. In response to Tata www.cam.ac.uk/system/files/a_bright_future_ processes by which recycling happens are out Steel’s decision, UK taxpayers will have to bear for_uk_steel_2.pdf

22 University of Cambridge Department of Engineering Issue 20 Autumn 2016 Professor Lord Uganda’s 2012 and 2050 agricultural resource Honours, awards Mair, head of the demand at national, district and local scales. Department of and prizes Engineering’s Centre Dr Mark Ainslie, for Smart Infrastructure Research Fellow in the and Construction Bulk Superconductivity (CSIC), made his Group of the maiden speech to the Department of House of Lords.The Engineering, recently speech, which was part presented his research of a wider debate about the High Speed Rail Bill to Parliament. A (London – West Midlands), made an impressive King’s College Junior case for investment in infrastructure and Research Fellow and research to secure a stronger future economy a Royal Academy of Engineering Research and stimulate growth. Lord Mair championed Fellow, Mark was shortlisted from hundreds of the role of innovation in engineering and smart applicants to take part in SET for Britain, a poster infrastructure suggesting the benefits and competition in Westminster for early-stage and commercial opportunities that investment in early-career researchers. Mark’s poster featured Professor Dame Ann Dowling OM DBE science and technology will bring. his research on compact and energy-efficient FREng FRS, President of the Royal Academy superconducting electric machines using high- of Engineering, has formally joined the highly Stefania C. temperature superconductors. prestigious Order of Merit. Radopoulou has been awarded a Dame Ann is the first female engineer to join The Materials Research Fiatech Outstanding the Order of Merit (OM), which only has 24 Society (MRS) has Student Research living members at any time. She is only the recognised Professor Project prize for her tenth woman in over 100 years to join the OM, Andrea Ferrari, work in developing following in the footsteps of some uniquely Director of the road infrastructure accomplished women from politics, science Cambridge Graphene sensor systems in and the arts. Centre, as a 2016 vehicles.Stefania is a MRS Fellow. Professor PhD student in the Construction Information Ferrari was cited “for Professor Norman Technology Laboratory, part of the Laing seminal research on Fleck, head of O’Rourke Centre for Construction Engineering Raman spectroscopy of carbon materials and the Department’s and Technology in the Department of leadership role in the development of graphene Materials Engineering Engineering. Her research objective is to create and other two-dimensional materials in Europe Group and Director of a novel framework that, when combined and worldwide.”The honour of MRS Fellow is the Cambridge Centre with low-cost vehicle sensors into a system, is bestowed upon outstanding members of the for Micromechanics, able to detect the type, location, and severity organisation in recognition of their sustained has received a €2.5 of defects and damages on road assets for and distinguished contributions to the million grant from the condition assessment purposes. advancement of materials research. European Research Council (ERC) to advance his engineering work Dr Dick Fenner and on advanced structural materials. MEng Student Dr Feriha Mukuve Srikanth Madabhushi have been awarded wins the best the Senior Moulton Dissertation Award from Medal for 2015 by the British Geotechnical Institution of Chemical Association (BGA). Engineers (IChemE) The British Geotechnical for a paper on “Scale Association (BGA) variability of water, land gives out annually the We are delighted to announce that the and energy resource best Dissertation in established and world-leading Interdisciplinary interactions and their influence on the food any MSc or MEng program in the UK. Srikanth Design for the Built Environment (IDBE) system in Uganda“ and published in the Journal Madabhushi won the prize for his MEng masters course for built environment of Sustainable Production and Consumption. dissertation titled “Investigating the Deformation professionals, run by the Departments of The work is forward looking on a very topical Mechanisms beneath Shallow Foundations” Engineering and Architecture for over twenty issue of sustainability facing many countries. The supervised by Dr Stuart Haigh, who is a Senior years, is being revised, revitalised and enhanced. authors have produced a very well written and Lecturer at the Department. The new course will be designed to take clearly presented piece of work making it ideal advantage of the many exciting new initiatives in for others to replicate and use in future work. infrastructure and the built environment in both departments. All potential applicants are invited The paper looks at future resource pathways, to apply in 2017. and describes a resource analysis in relation to

Issue 20 Autumn 2016 University of Cambridge Department of Engineering 23 Laser technique promises super-fast and super-secure quantum cryptography

A new method of implementing an ‘unbreakable’ quantum cryptographic system is able to transmit information at rates more than ten times faster

than previous attempts. Comandar Lucian Credit:

Researchers have developed a new method The strength of quantum cryptography is n Depiction of indistinguishable photons leaving to overcome one of the main issues in that if an attacker tries to intercept Alice and through the same output port of a beam splitter implementing a quantum cryptography Bob’s message, the key itself changes, due to system, raising the prospect of a useable the properties of quantum mechanics. Since ‘unbreakable’ method for sending sensitive it was first proposed in the 1980s, quantum MDI-QKD has been experimentally information hidden inside particles of light. cryptography has promised the possibility of demonstrated, but the rates at which By ‘seeding’ one laser beam inside unbreakable security. “In theory, the attacker information can be sent are too slow for real- another, the researchers, from the University could have all of the power possible under world application, mostly due to the difficulty of Cambridge and Toshiba Research Europe, the laws of physics, but they still wouldn’t be in creating indistinguishable particles from have demonstrated that it is possible to able to crack the code,” said the paper’s first different lasers. To make it work, the laser distribute encryption keys at rates between author Lucian Comandar, a PhD student at pulses sent through Charlie’s beam splitter two and six orders of magnitude higher than Cambridge’s Department of Engineering and need to be (relatively) long, restricting rates to earlier attempts at a real-world quantum Toshiba’s Cambridge Research Laboratory. a few hundred bits per second (bps) or less. cryptography system. The results are reported However, issues with quantum The method developed by the Cambridge in the journal Nature Photonics. cryptography arise when trying to construct a researchers overcomes the problem by using Encryption is a vital part of modern life, useable system. In reality, it is a back and forth a technique known as pulsed laser seeding, enabling sensitive information to be shared game: inventive attacks targeting different in which one laser beam injects photons into securely. In conventional cryptography, the components of the system are constantly being another. This makes the laser pulses more sender and receiver of a particular piece of developed, and countermeasures to foil attacks visible to Charlie by reducing the amount of information decide the encryption code, or are constantly being developed in response. ‘time jitter’ in the pulses, so that much shorter key, up front, so that only those with the key The components that are most frequently pulses can be used. Pulsed laser seeding is can decrypt the information. But as computers attacked by hackers are the photon detectors, also able to randomly change the phase of get faster and more powerful, encryption due to their high sensitivity and complex design the laser beam at very high rates. The result of codes get easier to break. – it is usually the most complex components using this technique in a MDI-QKD setup would Quantum cryptography promises that are the most vulnerable. As a response to enable rates as high as 1 megabit per second, ‘unbreakable’ security by hiding information attacks on the detectors, researchers developed representing an improvement of two to six in particles of light, or photons, emitted from a new quantum cryptography protocol known orders of magnitude over previous efforts. lasers. In this form of cryptography, quantum as measurement-device-independent quantum “This protocol gives us the highest possible mechanics are used to randomly generate a key distribution (MDI-QKD). degree of security at very high clock rates,” said key. The sender, who is normally designated In this method, instead of each having a Comandar. “It could point the way to a practical as Alice, sends the key via polarised photons, detector, Alice and Bob send their photons to implementation of quantum cryptography.” which are sent in different directions. The a central node, referred to as Charlie. Charlie receiver, normally designated as Bob, uses lets the photons pass through a beam splitter photon detectors to measure which direction and measures them. The results can disclose the photons are polarised, and the detectors the correlation between the bits, but not translate the photons into bits, which, assuming disclose their values, which remain secret. In R Bob has used the correct photon detectors in this set-up, even if Charlie tries to cheat, the www.eng.cam.ac.uk/profiles/lcc44 the correct order, will give him the key. information will remain secure. www.eng.cam.ac.uk/profiles/rvp11

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