Design of Programmable Matter by Ara N. Knaian S.B. Electrical Science and Engineering (1999) Massachusetts Institute of Technology, Cambridge, MA M. Eng. Electrical Engineering and Computer Science (2000) Massachusetts Institute of Technology, Cambridge, MA Submitted to the Program in Media Arts and Sciences, School of Architecture and Planning, in partial fulfillment of the requirements for the degree of Master of Science in Media Arts and Sciences at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY February 2008 © 2008 Massachusetts Institute of Technology All Rights Reserved Author______________________________________________________________ Program in Media Arts and Sciences January 14, 2008 Certified by__________________________________________________________ Neil A. Gershenfeld Associate Professor of Media Arts and Sciences Director, Center for Bits and Atoms Accepted by_________________________________________________________ Deb K. Roy Associate Professor of Media Arts and Sciences Chair, Departmental Committee on Graduate Students Design of Programmable Matter by Ara N. Knaian Submitted to the Program in Media Arts and Sciences, School of Architecture and Planning on January 14, 2008 in partial fulfillment of the requirements for the degree of Master of Science in Media Arts and Sciences ABSTRACT Programmable matter is a proposed digital material having computation, sensing, actuation, and display as continuous properties active over its whole extent. Programmable matter would have many exciting applications, like paintable displays, shape-changing robots and tools, rapid prototyping, and sculpture-based haptic interfaces. Programmable matter would be composed of millimeter-scale autonomous microsystem particles, without internal moving parts, bound by electromagnetic forces or an adhesive binder. Particles can dissipate 10 mW heat, and store 6 J energy in an internal zinc-air battery. Photovoltaic cells provide 300 µW outdoors and 3.0 µW indoors. Painted systems can store battery reactants in the paint binder; 6 J / mm3 can be stored, and diffusion is fast enough to transport reactants to the particles. Capacitive power transfer is an efficient method to transfer power to sparse, randomly placed particles. Power from capacitive transfer is proportional to 2 VDD : 100µW at 3.3V and 12 mW at 35V. Inter-particle communication is possible via optical, near-field, and far-field electromagnetic systems. Optical systems allow communication with low area (sub-mm) particles, and 24 pJ/bit. Near-field electromagnetic gives precisely controlled neighborhoods, localization capability, and 37 pJ/bit. Far-field radio communication between widely spaced particles may be possible at 60 GHz; antennas that fit inside 1 mm3 exist; 2 complete transceivers do not. A 32-bit CPU uses less than 0.26 mm die area, 256K x 8 SRAM uses 1.1 mm2, and 256K x 8 FLASH uses 0.32 mm2. Direct-drive electric and magnetic field systems allow actuation without moving parts inside the particles. Magnetic surface-drive motors designed for operation without bearings are not power-efficient, and parasitic interactions between permanent magnets may limit their usefulness at millimeter particle dimensions. Electrostatic surface-drive motors are power-efficient, but practical only at particle dimensions below a few millimeters. We constructed a prototype paintable display; a distributed PostScript rendering system with 1000 randomly-placed 3.4 cm nodes, each with a CPU, IR communications, and LED. The system is used to render the letter “A.” We present a design, not yet constructed, for a literal paintable display, with 1.0 mm rendering particles, each with a microprocessor and memory, and 110 µm display particles, with tri-color LED’s and simpler circuitry. Storage of zinc-air battery reactants in the paint binder would provide an 8 hour battery life, and capacitive power distribution would allow continuous operation. We constructed a prototype sliding-cube modular robot, with 3.4 cm nodes. The system uses magnetic surface-drive actuation. We demonstrate horizontal lattice-unit translation. We describe a design, not yet constructed, for a sliding-cube modular robot with 2 mm nodes. The cubes use standard-process CMOS IC’s, inserted into a cubic space frame and wire-bonded together. Arrays of passivated electrodes, 1 µm from the surface of the cubes, are used for electrostatic surface-drive actuation, zero-power latching, power transfer, localization, and communication. The design allows actuation from any contacting position. Energy is stored in a standard SMT capacitor inside each node, which is recharged by power transfer through chains of contacting nodes. Thesis Supervisor: Dr. Neil A. Gershenfeld Title: Associate Professor of Media Arts and Sciences Director, Center for Bits and Atoms 2 Design of Programmable Matter by Ara N. Knaian Submitted to the Program in Media Arts and Sciences, School of Architecture and Planning on January 14, 2008 in partial fulfillment of the requirements for the degree of Master of Science in Media Arts and Sciences Thesis Supervisor__________________________________________________ Neil A. Gershenfeld Associate Professor of Media Arts and Sciences Director, Center for Bits and Atoms Thesis Reader_____________________________________________________ Joseph M. Jacobson Associate Professor of Media Arts and Sciences MIT Media Lab Thesis Reader_____________________________________________________ Daniela L. Rus Professor of Electrical Engineering and Computer Science Co-Director, CSAIL Center for Robotics 3 THIS PAGE INTENTIONALLY LEFT BLANK 4 ACKNOWLEDGEMENTS This work was supported in part by the Center for Bits and Atoms, NSF, DARPA, and DTO. Thanks first to Neil Gershenfeld, for creating such a spectacularly interesting place to work, and assembling such a wonderful group of people with whom to do that work. Thanks to Joe Jacobson and Bill Butera, for the free-wheeling discussions that posed the questions that this thesis attempts to answer. Without them, this thesis would probably have been about some other topic entirely. Thanks to Neil Gershenfeld, Joe Jacobson, Daniela Rus, Carol Livermore, Saul Griffith, Mark Pavicic, and Bill Butera, for being my mentors: pointing out literature I needed to read, helping me sharpen my ideas, and through their feedback and guidance making my work so much better. Very direct thanks go to Forrest Green, David Greenspan, and Monica Sun, exceptionally talented undergraduate researchers with whom it was a pleasure to work, and who will certainly recognize many of the ideas in this thesis as springing from one of our late-night conversations. Beyond this, I want to point out that David and Monica wrote 100% of the code for the process- fragment paintable display, a huge job. Thanks to my lab-mates and fellow students; although we work on individual projects in theory, all of our work bears each other’s undeniable imprint in practice. In particular, I want to thank Amy Sun, Nels Peterson, Kenny Cheung, Manu Prakash, George Popescu, David Darlyrymple, Jon Santiago, David Kopp, Kerry Lynn, Ilan Moyer, Luis Lafuente, Kailang Chen, Mike Hennebry, Marty Vona, Dan Goldwater, Jason Taylor, Ben Recht, Xu Sun, Raffi Krikorian, Yael Maguire, Ben Vigoda, Brian Chow, Jaebum Joo, and David Mosley. I can remember several times when there was a deadline to meet, and everyone around the lab pitched in to help out. I can vividly remember Amy and Kenny doing lasercutter magic to build cube frames to my absurd specifications, Nels prototyping magnet patterns, George assembling cubes, David and Luis helping me to debug the electrostatic tiles in the Fluorinert caves of Fargo, and Jason writing a script to automate programming 1000 processors. Susan Bottari, Sherry Lassiter, Kelly Maenpaa, Mike Houlihan, and Joe Murphy did a spectacular job keeping supplies and equipment flowing into the lab at a sometimes breakneck pace, among plenty of other responsibilities. Thanks also to Linda Peterson, Gigi Shafer, and Marilyn Pierce, for making sure I had the right paperwork submitted on time, and generally looking out for me academically. John DiFrancesco and Tom Lutz run a great machine shop, and were always willing to lend a hand to help figure our how to get something built. Thanks to Harry Keller, David Newburg, Mr. Martins, Mr. Wells, and Dr. Duffy. Thanks to my parents, for the obvious, but also for getting me interested in science and engineering in the first place. Finally, thanks to Linda, for her constant friendship, support, and love. 5 TABLE OF CONTENTS Page 1 INTRODUCTION ....................................................................................................................8 1.1 Personal Fabrication and Digital Materials .................................................................... 8 1.2 Programmable Matter .................................................................................................. 11 1.3 The Present Moment in Semiconductor Manufacturing............................................... 12 1.4 Scope ...........................................................................................................................13 1.5 Background .................................................................................................................. 14 2 PHYSICS, MATERIALS, AND DEVICES ............................................................................. 18 2.1 Heat.............................................................................................................................