NSF CCR-0122419
June 29, 2008

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Activities and Findings

  1. Describe the major research and education activities of the project.

    The Center for Bits and Atoms is an interdisciplinary initiative exploring the interface between physical science and computer science. CBA comprises roughly 15 research groups from across MIT's campus, including physicists, biologists, chemists, mathematicians, computer scientists, electrical and mechanical engineers, and architects, all working at the boundary between bits and atoms.

    CBA researchers have programmed the dynamics of systems ranging from nuclear spins to trapped ions to genetic regulatory networks to microfluidic flows to mechanical structures to analog logic circuits to conformal computing substrates. These pioneering experiments are approaching a limit in which the number of information-bearing degrees of freedom becomes comparable to the number of physical ones. Beyond this point it's no longer possible to distinguish between computer science and physical science, because they're describing the same attributes. CBA's research is revisiting the foundations of both, by exposing rather than hiding the boundary between hardware and software. Among the consequences of investigating this fundamental connection, CBA's work has:

    CBA's research program is enabled by its investment in shared research infrastructure for input and output from nanometers to meters, and is supported by specialized training through a number of associated project-based classes. The work reaches beyond campus through topical meetings that have assembled emerging research communities in these areas, technology transfer via a number of industrial collaborations, and outreach through field "fab labs" that are bringing prototype tools for personal fabrication around the world.

  2. Describe the major findings resulting from these activities.

    A core research theme across CBA's activities is the digitization of fabrication, investigating the programmed rather than self-assembly of materials that can locally encode global structures. Fundamental principles of digital fabrication have been demonstrated [Griffith et al., 2005], including arbitrary shapes folded from a one-dimensional magnetic code:


    templated replication of a string of mechanical finite-state machines:


    and error-corrected growth of a perfect crystal formed from electromechanical tiles:

    Analogous to the earlier results that formed the basis for the digitization of communications and computation, theoretical work in CBA is addressing questions including error-correction thresholds in fabrication and geometrical universality. In [Griffith et al., 2005] it was shown that the problem of finding a non-intersecting path to fold an arbitrary structure (equivalent to the Hamiltonian Path problem) can be reduced to the much simpler task of finding a spanning tree by increasing the spatial resolution by a factor of four in 2D or six in 3D, with a constructive solution using four types of vertex-connected squares in 2D or two types of edge-connected right-angle tetrahedrons in 3D.

    Related CBA activities across a wide range of length scales are investigating the foundations of fabrication in locally encoding global structures. Macroscopically, a "shape grammar" for wood frame construction was developed to represent the design of a building in coded joints:

    which can be assembled from press-fit panels produced with two-dimensional rapid-prototyping tools. This approach promises to reduce the cost of construction in time, labor, and materials, and even more importantly to enable rapid customization of low-cost construction that is responsive to local needs [Sass, 2005; Sass and Botha, 2006]. Current work is investigating the automated assembly of large-scale digital structures [Cheung and Gershenfeld, 2008]:


    On mesoscopic scales, CBA researchers are developing the materials science of functional digital materials, with properties that can be tuned through their reversible assembly [Popescu et al., 2006]:

    Microscopically, peptides were used to assemble nanoparticles. Monofunctionalized gold nanoparticles were synthesized with L-lysine (Lys) linkers by a solid-phase reaction using 4-hydroxymethylphenoxyacetyl (HMPA) -- polyethylene glycolacrylamide copolymer (PEGA) resin [Sung et al., 2004]:

    The monofunctionalization was confirmed by HRTEM observation of dimerization of the nanoparticles:

    On molecular scales, the detection and removal of errors in the assembly of oligonucleotides was demonstrated, with a goal of reliable de novo synthesis of gene-length DNA. The mismatch-binding protein MutS (from Thermus aquaticus) was used to eliminate failure products from synthetic genes, shown here on the right applied to the expression of Green Fluorescent Protein (GFP) (greater than 95% of colonies fluorescent) [Carr et al., 2004]:

    This approach reduced errors by greater than a factor of 15 relative to conventional gene synthesis techniques, yielding DNA with one error per 10,000 base pairs, and can be iterated for greater fidelity. To create custom microarrays, semiconductor photoelectrochemistry was used for in-situ DNA synthesis [Chow, 2008]:


    For programmed control of gene expression, site-specific nanoparticle labels were developed. Gold nanoparticles were covalently bonded to a peptide (S18), which self-assembles with the S-protein to form a functional RNase S complex [Park et al., 2004; Audin et al., 2005]:

    Under radio-frequency irradiation such a gold nanoparticle label was shown to reversibly switch the hybridization and hence functionality of an attached DNA hairpin loop, here observed by the UV absorbance [Hamad-Schifferli et al., 2002]:

    Nanoparticles and proteins were conjugated to quantify their interface, and exploited to control the folding properties of proteins [Aubin-Tam and Hamad-Schifferli, 2005].

    For additive patterning of nanoparticles, an offset liquid embossing process was developed. This transfers patterned material from a polydimethylsiloxane surface of tuned wettability to a rigid or flexible substrate. The printing is fast (seconds), can be done under ambient conditions, and multiple layers can be aligned and printed without the need for planarization
    [Wilhelm and Jacobson, 2004]:

    The offset liquid embossing process was used to print micro-electromechanical systems, here producing electrostatic actuators for light modulation (imaging the displacement with CBA's confocal microscope) [Wilhelm et al., 2004]:

    For finer features, CBA's Focused Ion Beam writer (FIB) was used to directly pattern organometallic nanoparticles to produce nanometer-scale wiring:

    showing the highest demonstrated throughput for a direct-write process utilizing organometallic precursors [Kong et al., 2004], and CBA's e-beam writer was used with the FIB to fabricate field effect transistors from semiconducting nanowires [Joo et al., 2007]:


    CBA's FIB was also used to notch a SOI substrate that was then fractured at that interface to create a controllable atomically-flat gap:

    that can be used as a molecular-scale valve [Sprunt and Slocum, 2005]; variable microscale gaps were also used for calibration-free complex impedance spectroscopy of liquids and gases [Ma and Slocum, 2006; Ma et al., 2007].

    Molecular detection was shown by a field-effect sensor for electronic readout of DNA hybridization. The charge per base at the sugar-phosphate backbone extends the size of an underlying depletion region in the device, shown here differentially detecting an oligonucleotide
    [Fritz et al., 2002]:

    A suspended microchannel resonant mass sensor provided microfluidic integration and significantly reduced ambient damping for such functionalized silicon surfaces [Burg and Manalis, 2003], and an integrated tunneling tip and interferometric sensor provided coherent noise cancellation [Sparks and Manalis, 2004]. Measurement of amplicon intrinsic charge was integrated with resistive heaters, temperature sensors, and microfluidic valves for label-free nucleic acid amplification and detection [Hou et al., 2007]:


    For molecular structural studies, CBA's excimer laser micromachining system was used to fabricate a slot antenna in a microstripline that creates an impedance-matched discontinuity that locally converts RF energy to a strong homogeneous magnetic field. This has demonstrated the best reported sensitivity for an integrated spin-resonance probe, here showing the two-dimensional spectra obtained from a picomolar sample of an acetyl-amide peptide [Maguire et al., 2007]:


    Molecular devices were developed based on the functionality that is available in membrane proteins. Peptide surfactants were synthesized to solubilize, stabilize and crystallize membrane proteins so that they can be used outside of a cell [Yang, 2004]:

    These were used to retain the functionality of the photosystem 1 (PS1) complex (from spinach) on a transparent conducting surface [Kiley et al., 2005]:

    Carbon nanotubes were then used for electron capture from the PS1, to create a photosynthetic photovoltaic device [Das et al., 2004].

    For molecular computation, CBA support contributed to the development of techniques based on nuclear magnetic spin resonance [Gershenfeld and Chuang, 1997; Vandersypen and Chuang, 2004] that led to some of the earliest and largest quantum computations to date. Following the initial implementation of quantum searching [Chuang, Gershenfeld, and Kubinec, 1998], these include adiabatic optimization [Steffen et al., 2003], and factoring [Vandersypen et al., 2001], here showing the 7-qubit molecule (a perfluorobutadienyl iron complex), circuit, pulse sequence, and spectra for Shor's algorithm:

    Pulse sequences developed for computing with nuclear spins were subsequently applied to ion trap quantum computers, [Guide et al., 2003], and investigation of their scaling resulted in the experimental realization of a planar ion trap array [Pearson et al., 2006], showing loading from a conventional linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through intersections:

    Beyond computation, CBA researchers are applying concepts from quantum information to problems ranging from the study of materials [Lloyd, 2008] to quantum gravity [Lloyd, 2006] and the computational capacity of the universe [Lloyd, 2002]. Results include an interferometric measurement of the phase coherence of dark states in Electromagnetically Induced Transparency (EIT) [Murali et al., 2004], beating the standard quantum limit in a positioning system such as GPS by viewing it as a distributed computation [Giovannetti, Lloyd, and Maccone, 2004], and analyzing the escape of quantum information in the Hawking radiation from a black hole [Lloyd, 2004].

    CBA's investigation of the transformation of information in physical interactions has led to advances in coherent classical as well as quantum mechanisms. A new approach to information security came from introducing a physical one-way cryptographic function by showing that photon scattering from inhomogeneous materials in the mesoscopic limit is equivalent to a one-way hash of the scattering structure
    [Pappu et al., 2002]:


    And CBA's fabrication facilities were used in the first measurement of the two-dimensional electromagnetic scattering profile of the focusing inside and outside of a negative-index material [Houck et al., 2003; Brock, 2004]:

    The study of the integration of computation into materials led to the invention of "bubble logic", using two-phase flows in microfluidic channels to simultaneously transport materials and perform logic on them, here showing bubble generation, logic, bistability, and a ring oscillator
    [Prakash and Gershenfeld, 2007]:

    Capillary ratchets that can clock microfluidic circuits were discovered from studying the foraging mechanisms of shorebirds [Prakash et al., 2008].

    CBA's studies of these microscopic means for manipulating information promise to lead to the creation of macroscopic systems of unprecedented complexity. Along with investigating the foundations of computation and fabrication, a number of CBA projects are exploring design principles and engineering practice appropriate for this limit of enormous complexity. An emerging programming model is based on "mathematical programming," compiling problems posed as a mathematical program (goals with constraints) into distributed dynamics by message-passing algorithms on the graphical structure associated with sparsity in the primal and dual problem statements. This approach was applied to spread-spectrum carrier acquisition and tracking:

    to create a Noise-Locked Loop (NLL) as a generalization of Phase-Locked Loops (PLLs) to coded waveforms [Vigoda, 2003; Vigoda et al., 2006]. An NLL circuit was implemented, here compared to simple bit-discrimination on a noisy signal:

    This "analog logic" circuit operates in the state-space of the corresponding digital system but uses a continuous log-likelihood voltage representation that takes advantage of the available device degrees of freedom.

    A related project has taken early ideas about fault-tolerant computers that have since been developed for quantum computing and applied them back to classical logic, showing that fault-tolerant designs can improve the reliability and resource efficiency of classical circuits
    [Impens, 2004]:

    Other work on electronics that operates between analog and digital limits has included the development of an ultra-low-leakage analog storage cell [O'Halloran and Sarpeshkar, 2004], spike-based signal processing [O'Halloran and Sarpeshkar, 2002], and a time-based analog-to-digital converter inspired by the operation of spiking neurons:

    offering the first conversion time that scales linearly rather than exponentially with bit precision, and the highest reported A/D energy efficiency [Yang and Sarpeshkar, 2006].

    Computation in distributed systems was investigated in the context of "paintable" computing, seeking to turn computation into an extensible raw material by fabricating enormous numbers of simple devices that can solve global problems through their local interactions. To guide scaling to silicon, a programming model for a paintable computer was implemented in a pushpin system, taking as a test problem distributed graphical rendering in a statistical display medium:

    [Butera, 2002], and a similar system was used to study distributed localization [Broxton et al., 2005]. The physical constraints on distributed computation were reflected in the development of conformal computing substrates [Gershenfeld, 2008] based on asynchronous logic automata [Dalrymple, 2008] assembled by coded folding [Cheung et al., 2008]:


    Current work is extending this architecutre to develop analog logic automata chips for reconfigurable mixed-signal and statistical processing.

    Investigation in CBA of the connection between computational and physical dynamics resulted in the development of a dynamically stable bipedal robot that learns to walk in 20 minutes
    [Tedrake, 2004; Collins et al., 2005]:

    Current work is extending the online learning algorithms to more complex mechanical systems and terrains [Byl and Tedrake, 2008]. The relationship between mathematical and physical mechanisms for learning is also being investigated at the cellular level, including the development of a printing process to pattern networks of neurons and glia cells [Sanjana and Fuller, 2003]:

    CBA facilities were used to develop the first-ever method for silencing neural activity with light [Han and Boyden, 2007]:


    and to make arrays for optically switching on and off 3D  brain circuits [Bernstein et al., 2008]. These studies of learning in biological systems are closely connected to CBA's investigation of mathematical programming in engineered systems, which is seeking to forward- rather than reverse-engineer the biological principles underlying the use of local interactions to solve global problems [Lafuente and Gershenfeld, 2008].

  3. Describe the opportunities for training and development provided by your project.

    CBA has directly supported about 100 grad and undergrad students and indirectly contributed to training about 200 students (with two subsequently joining MIT's faculty), working with a unique experimental resource developed to provide input and output across 9 orders of magnitude:

    A popular rapid-prototyping class was developed to provide instruction in its integrated use, MAS.863: How To Make (almost) Anything. Other classes that have been developed with direct and indirect CBA contributions include:





    CBA's educational activities have expanded beyond campus, through activities in the field fab lab network including a 10 module "FabKidz" curriculum aimed at 6th-8th grade school children that was developed and administered by a 15-year-old fab lab participant (who's been working in a fab lab since she was 12) [Millner and Daily, 2008]:


    and a NSF grant (0802388) to the Midwest Fab Lab Network to integrate and analyze the impact of digital fabrication in community college curriculum.

  4. Describe outreach activities your project has undertaken.

    The focus of CBA's outreach activities has been a growing network of field "fab labs":



    [Gershenfeld, 2005]. Rather than just communicating research results, fab labs provide access to prototype tools for personal fabrication in underserved communities around the world, allowing ordinary people to create as well as consume technology. Fab lab activities range from technological empowerment to informal project-based peer-to-peer technical training, to local problem-solving, to small-scale high-tech business creation, to grass-roots research and development; projects include high-gain antennas for mesh wireless networks, low-cost locally-produced thin-client computers, instrumentation for environmental, agricultural, and medical measurements, wind, water, and steam turbines, and rapid-prototyping of housing:

    Fab labs have spread in the US from inner-city Boston to the Midwest to San Diego and the South Bronx, in Europe from the north of Norway to Barcelona and the Netherlands, in Africa from Ghana to South Africa to Kenya, to India, and (with supplemental NSF support) Afghanistan. CBA supports these labs with communications infrastructure (including hosting a broadband videoconference), by managing shared inventory and capabilities, and developing projects and processes (with an ultimate aim of a fab lab being able to make a fab lab).

    Fab lab sites include formal and informal institutions, community centers and community colleges, farms and studios. Financial support, initially from CBA, has expanded to include other philanthropic sources (such as a MacArthur Foundation award to the South Bronx fab lab) and government sources (such as South Africa's national fab lab network). This response has been matched by public and press interest, with features in media including The Economist, USA Today, NPR, BBC, and CNN.

    To keep up with the growth of fab labs, an independent non-profit Fab Foundation is being launched to support invention as aid, a for-profit Fab Fund to help global capital reach local inventors and local inventions find global markets, and a Fab Academy to provide distributed advanced technical education in principles and applications of digital fabrication. The emergence of these organizations can be understood as an ultimate impact of the work of CBA and its partners. Bringing together computer science and physical science has led to the development of digital fabrication, in turn enabling personal fabrication. And the availability of prototype tools for personal fabrication is allowing anyone anywhere to be able to make almost anything. Combined with video networks and online libraries, this means that previously scarce resources of advanced research and educational institutions can become much more widely distributed and broadly accessible.

    Since 2004 CBA has co-organized an annual
    global gathering of the field fab lab and digital fabrication research communities, co-hosted in 2007 with NSF and the Department of Energy: http://cba.mit.edu/events/07.08.fab/. A mobile fab lab was developed for this event, here shown at Chicago's Museum of Science and Industry:

    Such topical meetings targeting emerging research areas have been an important component of CBA's outreach within the scientific community. These have included meetings on Coding and Computation in Microfluidics [http://cba.mit.edu/events/07.05.fluid/], Energy and Computation: Flops/Watt and Watts/Flop [http://cba.mit.edu/events/06.05.energy/], Digital Fabrication [http://cba.mit.edu/events/06.06.ZA/symposium.html], Avogadro-Scale Engineering [http://cba.mit.edu/events/03.11.ASE/], Quantum Information Processing [http://cba.mit.edu/events/05.01.QIP/]

    and Internet 0 [http://cba.mit.edu/events/04.09.I0/]. The latter gathered original Internet architects as well as current counterparts, and industrial partners. At the meeting a parallel was seen between the early days of the Internet and embedded networking today, with Internet 0's time-domain impulse-response encoding:

    providing end-to-end modulation to enable interdevice internetworking:

    [Gershenfeld et al., 2004; Gershenfeld and Cohen, 2006]. A follow-up event on energy applications [http://cba.mit.edu/events/07.05.energy/] led to launching a project on Intelligent Infrastructure for Energy Efficiency (I2E), in cooperation with Department of Energy national labs and industrial partners, for large-scale testbeds applying Internet 0 to building energy efficiency:


    Another form of outreach has been through projects using CBA's rapid-prototyping facilities. One is a concept car project with Prof. Bill Mitchell, Frank Gehry, and General Motors that is developing an electric one-way share vehicle:

    Another is with Drs. Florence Friedman (Brown University) and Walter Gilbert (Harvard University), working with CBA's shop technician John Difrancesco to 3D scan, virtually assemble, and print fragments of antiquities from the collection of Boston's Museum of Fine Arts:

Publications and Products

  1. What have you published as a result of this work?
    Journal publications

    M. Aubin-Tam and K. Hamad-Schifferli, "Cytochrome c Complexes: The Effect of Nanoparticle Ligand Charge on Protein Structure,"
    Langmuir (21), pp. 12080-12084 (2005)

    M.-E. Audin, D.G. Morales, K. Hamad-Schifferli, "Labeling Ribonuclease S with a 3nm Au nanoparticle by two-step assembly,"
    Nano Lett. 5 (3), 519-522 (2005)

    D. Baker, G. Church, J. Collins, D. Endy, J. Jacobson, J. Keasling, P. Modrich, C. Smolke, and R. Weiss, "Engineering Life: Building a FAB for Biology,"
    Scientific American (294), pp. 44-51 (2006)

    J. Bernstein, X. Han, M. Henninger, E. Ko, X. Qian, G. Talei Franzesi, J. McConnell, P. Stern, R. Desimone, E.S. Boyden, "Prosthetic Systems for Therapeutic Optical Activation and Silencing of Genetically-Targeted Neurons," Proceedings of the SPIE Vol. 6854, 68540H:1-11, Optical Interactions with Tissue and Cells XIX, Steven L. Jacques; William P. Roach; Robert J. Thomas, Editors (2008)

    Jeffrey B. Brock, Andrew A. Houck, and Isaac L. Chuang, "Focusing inside negative index materials,"
    Applied Physics Letters (85), pp. 2472-4 (2004)

    M. Broxton, J. Lifton, J.A. Paradiso, "Wireless Sensor Node
    Localization Using Spectral Graph Drawing and Mesh Relaxation," submitted (2005)

    C. Bulthaup, E. Wilhelm, B. Hubert, B. Ridley, and J. Jacobson, "All-Additive Fabrication of Inorganic Logic Elements by Liquid Embossing," Applied Physics Letters (79), pp. 1525-1527 (2001)

    T. Burg and S.R. Manalis, "Suspended microchannel resonators for biomolecular detection," Applied Physics Letters (83), 2698 (2003)

    Katie Byl and Russ Tedrake, "Metastable Walking on Stochastically Rough Terrain," in Proceedings of Robotics: Science and Systems IV (2008)

    Peter A. Carr, Jason S. Park, Yoon-Jae Lee, Tiffany Yu, Shuguang Zhang, and Joseph M. Jacobson, "Protein-mediated error correction for de novo DNA synthesis,"
    Nucleic Acids Research 32 (20),  e162/1-e162/9 (2004)

    Kenneth Cheung, Erik Demaine, Neil Gershenfeld, "Folding Programs," to be published (2008)

    K. Cheung and N. Gershenfeld, "Automated Assembly of Large-Scale Digital Structures," to be published (2008)

    T. Choudhury, B. Clarkson, S. Basu, and A. Pentland, "Learning Communities: Connectivity and Dynamics of Interacting Agents
    ," Proceedings of the International Joint Conference on Neural Networks, 2003

    Brian Y. Chow, David W. Mosley, and Joseph M. Jacobson, "Perfecting Imperfect Monolayers: Removal of Siloxane Multilayers by CO2 Snow Treatment,"
    Langmuir  21(11),  pp. 4782-4785 (2005)

    Isaac L. Chuang, Neil Gershenfeld, and Mark Kubinec, "Experimental Implementation of Fast Quantum Searching," Phys. Rev. Lett. (80), pp. 3408-3411 (1998)

    Steven H. Collins, Andy Ruina, Russ Tedrake, and Martijn Wisse, "Efficient bipedal robots based on passive-dynamic walkers",
    Science (307), pp. 1082-1085 (2005)

    E.B. Cooper, J. Fritz, G. Wiegand, P. Wagner, and S.R. Manalis, "Robust Microfabricated Field-Effect Sensor for Monitoring Molecular Adsorption in Liquids," Applied Physics Letters  (79), pp. 3875-3877 (2001)

    J. Fritz, E.B. Cooper, S. Gaudet, et al., "Electronic Detection of DNA by its Intrinsic Molecular Charge," P. Nat. Acad. Sci (99), pp. 14142-14146 (2002)

    R. Das, P.J. Kiley, M. Segal, J. Norville, A. Yu, L. Wang, S. Trammell, L.E. Reddick, R. Kumar, F. Stellacci, N. Lebedev, J.M Schnur, B.D. Bruce, S. Zhang, and M. Baldo, "Integration of phtosynthetic protein molecular complexes in solid-state electronic device,"
    Nano Letters (4), pp. 1079-1083 (2004)

    S.B. Fuller, E.J. Wilhelm, and J.M. Jacobson, "Ink-jet Printed Nanoparticle Microelectromechanical Systems," Journal of Microelectromechanical Systems (11), pp. 54-60 (2002)

    N. Gershenfeld, R. Krikorian, and D. Cohen, "The Internet of Things," Scientific American (291), pp. 76-81 (2004)

    Neil A. Gershenfeld and Isaac L. Chuang, "Bulk Spin-Resonance Quantum Computation,"
    Science (275), pp. 350-356 (1997)

    N. Gershenfeld and D. Cohen, "Internet 0: Interdevice Internetworking,"
    IEEE Circuits and Devices (22), pp. 48-55 (2006)

    Neil Gershenfeld, "Programming Bits and Atoms", to be published (2008)

    Vittorio Giovannetti, Seth Lloyd, and Lorenzo Maccone, "Quantum-Enhanced Measurements: Beating the Standard Quantum Limit,"
    Science (19), pp. 1330-1336 (2004)

    D. Gottesman and I. Chuang, "Quantum Digital Signatures," http://arxiv.org/abs/quant-ph/0105032 (2001)

    S. Griffith, D. Goldwater, and J.M. Jacobson, "Self-Replication From Random Parts," 
    Nature (437), p. 636 (2005)

    Saul Griffith, James McBride, Benjamin Su, Bobby Ren, and Joseph M. Jacobson, "Folding Any 3D Shape," to be published (2005).

    Saul Griffith, Mark Mondol, David S. Kong, and Joseph M. Jacobson,
    "Nanostructure fabrication by direct electron-beam writing of nanoparticles," J. Vac. Sci. Technol. (B 20), 2768-2772 (2002)

    S. Gulde, M. Riebe, G.P.T. Lancaster, C. Becher, J. Eschner, H. Häffner, F. Schmidt-Kaler, I.L. Chuang, R. Blatt, "Implementing the Deutsch-Jozsa algorithm on an ion-trap quantum computer,"
    Nature (421), pp. 48-50 (2003)

    K. Hamad-Schifferli, J.J. Schwartz, A.T. Santos, S.G. Zhang, and J.M. Jacobson, "Remote Electronic Control of DNA Hybridization Through Inductive Coupling to an Attached Metal Nanocrystal Antenna,"  Nature (415), pp. 152-155, (2002)

    X. Han and E.S. Boyden, "Multiple-Color Optical Activation, Silencing, and Desynchronization of Neural Activity, with Single-Spike Temporal Resolution," PLoS ONE 2(3): e299 doi:10.1371/journal.pone.0000299 (2007)

    C.J. Hou, N. Milovic, M. Godin, P.R. Russo, R. Chakrabarti, and S.R. Manalis, "Label-free Microelectronic PCR Quantification,"
    Analytical Chemistry (78), p. 2526 (2006)

    C.J. Hou, M. Godin, K. Payer, R. Chakrabarti, S.R. Manalis, "Integrated Microelectronic Device for Label-free Nucleic Acid Amplification and Detection," Lab on a Chip (7), p. 347 (2007)

    A.A. Houck, J.B. Brock, and I.L. Chuang, "Experimental Observations of a Left-Handed Material That Obeys Snell's Law," Phys. Rev. Lett. (90), 137401/1-4 (2003)

    J. Joo, B.Y. Chow, and J.M. Jacobson, "Nanoscale Patterning on Insulating Substrates by Critical Energy Electron Beam Lithography,"
    Nano Letters (6), pp. 2021-2025 (2006)

    J.  Joo, S. Moon, and J.M. Jacobson, "Ultrafast Patterning of Nanoparticles by Electrostatic Lithography,"
    J. Vac. Sci. B., to appear (2006)

    Jaebum Joo, Kimin Jun, and Joseph M. Jacobson, "Simple fabrication of UV Nanoimprint Lithography Templates by Critical Energy Electron Beam Lithography," J. Vac. Sci. Technol. B (25), pp. 2407-2411 (2007)

    P. Kiley, X. Zhao, M. Vaughn, M. Baldo, B.D. Bruce, and S. Zhang, "Designed short peptide detergents stabilize the structure of photosystem I membrane protein complex,"
    PLoS Biol. 3, in press (2005)

    David S. Kong, Jonathan S. Varsanik, Saul Griffith, and Joseph M. Jacobson, "Conductive nanostructure fabrication by focused ion beam direct-writing of silver nanoparticles,"
    Journal of Vacuum Science & Technology, B: Microelectronics and Nanometer Structures--Processing, Measurement, and Phenomena 22(6),  2987-2991 (2004)

    D.S. Kong, V. Anant, A. Salomon, W. Delhagen, H. Nair, J. Varsanik and J.M. Jacobson, "Nanostructure Fabrication by Direct E-Beam Writing of Purely Inorganic Nanoparticles,"
    Intl. Conf. on Electron, Ion, and Photon Beam Technology and Nanofabrication (2003 )

    Luis Lafuente Molinero and Neil Gershenfeld, "Conformal Mathematics," to be published (2008)

    J. Lifton, D. Seetharam, M. Broxton, J. Paradiso, "Pushpin Computing System Overview: a Platform for Distributed, Embedded, Ubiquitous Sensor Networks," Proc. of the Int. Conf. on Pervasive Computing, Zurich (2002)

    Joshua Lifton, Deva Seetharam, Michael Broxton, Joseph Paradiso, "Pushpin Computing System Overview: a Platform for Distributed, Embedded, Ubiquitous Sensor Networks," in F. Mattern and M. Naghshineh (eds): Pervasive 2002, Proceedings of the Pervasive Computing Conference, Zurich Switzerland, 26-28 August 2002, Springer Verlag, Berlin Heidelberg, pp. 139-151

    S. Lloyd, "Computational Capacity of the Universe," Phys. Rev. Lett. (88), 237901 (2002)

    S. Lloyd, "Power of Entanglement in Quantum Communication," Phys. Rev. Lett. (90), 167902 (2003)

    S. Lloyd, "Almost certain escape from black holes," quant-ph/0406205 (2004)

    S. Lloyd. "A Theory of Quantum Gravity Based on Quantum Computation," arXiv:quant-ph/0501135v8 (2006)

    S. Lloyd, "Quantum Information Matters," Science (319), pp. 1209- 1211 (2008)

    A. Lomander, W. Hwang, and S. Zhang, "Hierarchical Self-Assembly of a Coiled-Coil Peptide Into Fractal Structure," Nano Letters (5), pp. 1255-1260 (2005)

    H. Ma, J. White, J. Paradiso, and A. Slocum, "Sub-nanometer Displacement Sensing for the Nanogate," In the Proceedings of the 2003 IEEE International Conference on Sensors, October 21-24, Toronto Canada, pp. 46-51 (2003)

    Hongshen Ma, J.H. Lang, and A.H. Slocum, "Design of an Electrochemical Impedance Test Cell with Servomechanically Adjustable Cell Constant," IEEE Sensors, pp. 1233-1236 (2007)

    M.J. MacLachlan, A. Rose, and T.M. Swager, "A Rotaxane Exciplex,” J. Am. Chem. Soc. (123), pp. 9180-9181 (2001)

    Y. Maguire, I.L. Chuang, S. Zhang, and N. Gershenfeld, "Ultra-Small-Sample Molecular Structure Detection Using Microslot Waveguide Nuclear Spin Resonance,"
    Proceedings of the National Academy of Sciences (104), pp. 9198-9203 (2007)

    B. Mikhak, C. Lyon, T. Gorton, N. Gershenfeld, C. McEnnis, J. Taylor, "FAB LAB: An Alternate Model of ICT for Development,"
    2nd International Conference on Open Collaborative Design for Sustainable Innovation, Bangalore, India, 2002

    N. Milovic, J. Behr, M. Godin, C.J. Hou, K.R. Payer, A. Chandrasekaran, P.R. Russo, R. Sasisekharan, and S.R. Manalis, "Monitoring of Heparin and Its Low Molecular Weight Analogs by Silicon Field Effect,"
    Proceedings of the National Academy of Sciences (2006).

    W.J. Mitchell, "Constructing Complexity in the Digital Age,"
    Science (303), pp. 1472-1473 (2004)

    D. Mosley, B.Y. Chow, and J.M. Jacobson, "Solid-State Bonding Technique for Template-Stripped Ultraflat Gold Substrates,"
    Langmuir (22), pp. 2437-2440 (2006)
     

    K.V.R.M. Murali, Hyung-Bin Song, Matthias Steffen, Patrick Judeinstein, and Isaac L. Chuang, "Test by NMR of the Phase Coherence of Electromagnetically Induced Transparency,"
    Phys. Rev. Lett. (93), 033601 (2004)

    M. O'Halloran and R. Sarpeshkar, "A 10-nW 12-bit Accurate Analog Storage Cell with 10-aA Leakage,"
    IEEE Journal of Solid State Circuits (39), pp. 1985-1996 (2004)

    M. O'Halloran and R. Sarpeshkar, "Scalable Hybrid Computation with Spikes,"
    Neural Computation (14), pp. 2003-2038 (2002)

    M. O’Halloran and R. Sarpeshkar, "A Low Open-Loop Gain, High-PSRR, Micropower CMOS Amplifier for Mixed-Signal Applications," Proc. of the IEEE Conf. On Circuits and Systems, (Vol. II), pp. 424-427 (2002)

    M. Oskin, F.T. Chong, I.L. Chuang IL, "A Practical Architecture for Reliable Quantum Computers",
    Computer (35), pp. 79-87 (2002)

    R. Pappu, B. Recht, J. Taylor, N. Gershenfeld, "Physical One-Way Functions," Science (297) pp. 2026-2030 (2002)

    S. Park, K.A. Brown, K. Hamad- Schifferli, "Changes in oligonucleotide conformation on nanoparticle surfaces by modification with mercaptohexanol,"
    Nano Lett. 4 (10), 1925-1929 (2004)

    C.E. Pearson, D.R. Leibrandt, W.S. Bakr, W.J. Mallard, K.R. Brown, and I.L. Chuang, "Experimental Investigation of Planar Ion Traps,"
    Phys. Rev. A (73), 032307 (2006)

    M. Prakash and N. Gershenfeld, "Microfludic Bubble Logic,"
    Science (315), pp. 832-835 (2007)

    Manu Prakash, David Quere and John W. M. Bush, "Surface Tension Transport of Prey by Feeding Shorebirds: The Capillary Ratchet," Science (320), pp. 931-934 (2008)

    M. Resnick, "Rethinking Learning in the Digital Age," in The Global Information Technology Report: Readiness for the Networked World, edited by G. Kirkman, Oxford University Press (2002)

    N. E. Sanjana and S. B. Fuller, "A fast flexible ink-jet printing method for patterning dissociated neurons in culture,"
    Journal of Neuroscience Methods (136), pp. 151-163 (2004)

    S. Santoso, W. Hwang, H. Hartman, S. Zhang, "Self-Assembly of Surfactant-Like Peptides with Variable Glycine Tails to Form Nanotubes and Nanovesicles,"
    NanoLetters (2), pp. 687-691 (2002)

    A.W. Sparks and S.R. Manalis, "Scanning probe microscopy with inherent disturbance suppression",
    Applied Physics Letters, (85), pp. 3929-3931 (2004)

    F. Standaert, G. Piret, N. Gershenfeld, and J. Quisquater, "SEA: a Scalable Encryption Algorithm for Small Embedded Applications," Springer Lecture Notes in Computer Science (3928), pp. 222-236 (2006)

    M. Steffen, J. Martinis, I. Chuang, "Accurate control of Josephson phase qubits,"
    Physical Review B (68), pp 224518/1-9, 2003

    M. Steffen, W. van Dam, T. Hogg, G. Breyta, and I. Chuang, "Experimental Implementation of an Adiabatic Quantum Optimization Algorithm,"
    Phys. Rev. Lett. (90), 067903 (2003)

    Kie-Moon Sung, David W. Mosley, Beau R. Peelle, Shuguang Zhang, and Joseph M. Jacobson, "Synthesis of Monofunctionalized Gold Nanoparticles by Fmoc Solid-Phase Reactions,"
    J. Am. Chem. Soc (126), 5064-5065 (2004)

    R. Tedrake and H. Sebastian Seung, "Improved Dynamic Stability using Reinforcement Learning," 5th International Conference on Climbing and Walking Robots (CLAWAR), Professional Engineering Publishing Limited (2002)

    Russ Tedrake, Teresa Weirui Zhang, Ming-fai Fong, and H. Sebastian Seung, "Actuating a Simple 3D Passive Dynamic Walker," IEEE International Conference on Robotics and Automation (ICRA 2004)

    L.M.K. Vandersypen and I.L. Chuang, "NMR Techniques for Quantum Control and Computation,"
    Rev. Mod. Phys. (76), pp. 1037-1069 (2004)

    M.K. Vandersypen, M. Steffen, G. Breyta, C.S. Yannoni, M.H. Sherwood, and I.L. Chuang, "Experimental Realization of Shor's Quantum Factoring Algorithm using Nuclear Magnetic Resonance," Nature (414), pp. 883-887 (2001)

    Eric J. Wilhelm, Brian T. Neltner, and Joseph M. Jacobson, "Nanoparticle-based microelectromechanical systems fabricated on plastic,"
    Applied Physics Letters (85),  pp. 6424-6426 (2004)

    Eric J. Wilhelm and Joseph M. Jacobson, "Direct printing of nanoparticles and spin-on-glasses by offset liquid embossing,"
    Appl. Phys. Lett. (84), 3507 (2004)

    D.W. Mosley, M.A. Sellmyer, J. Jacobson, "Formation, Patterning, and Polymerization of Surface Adlayers Using Self-Assembled Monolayers as Templates," Proceedings of the Materials Research Society, 2003

    David W. Mosley, Mark A. Sellmyer, Erin J. Daida, and Joseph M. Jacobson., "Polymerization of Diacetylenes by Hydrogen Bond Templated Adlayer Formation," J. Amer. Chem. Soc. (125), pp. 10532-33 (2003)

    B. Vigoda, H. Dauwels, M. Frey, N. Gershenfeld, T. Koch, H.-A. Loeliger, and P. Merkli, "Synchronization of Pseudo-Random Signals by Forward-Only Message Passing with Application to Electronics Circuits,"
    IEEE Transactions of Information Theory (52), pp. 3843-3852 (2006)

    H. Yang, and R. Sarpeshkar, "A Bio-inspired Ultra-Energy-Efficient Analog-to-Digital Converter for Biomedical Applications," IEEE Transactions on Circuits and Systems I (53), pp. 2349-2356 (2006)

    H. Yokoi, T. Kinoshita, and S. Zhang, "Dynamic Reassembly of Peptide RADA16 Nanofiber Scaffold,"
    Proc. Natl. Acad. Sci. (102), pp. 8414-8419 (2005)

    Zhang, S., "Fabrication of novel materials through molecular self-assembly," Nature Biotechnology (21), 1171-1178 (2003)

    O. Zuckerman and M. Resnick, "System Blocks: A Physical Interface for System Dynamics Learning," International System Dynamics Conference, New York City, 2003

    Books or other non-periodical, one-time publications

    Sumit Basu, Conversational Scene Analysis, Ph.D. thesis, MIT (2002)

    Robert Beverly, Statistical Learning in Network Architecture, Ph.D. thesis, MIT (2008)

    Rahul Bhargava,
    Designing a Computational Construction Kit for the Blind and Visusally Impaired , M.S. thesis, MIT (2002)

    Jeff Brock,
    Refraction and Focusing in Negative Index Materials, S.B. thesis (2003)

    W. Butera, Programming a Paintable Computer, Ph.D. thesis, MIT (2002)

    K. Byl and R. Tedrake, 
    Stability of Passive Dynamic Walking on Uneven Terrain in Proceedings of Dynamic Walking 2006, A. Kuo, editor (2006)

    Brian P. Clarkson,
    Life Patterns: structures from wearable sensors, Ph.D. thesis, MIT (2002)

    David Dalrymple, Asynchronous Logic Automata, M.S. thesis, MIT (2008)

    S.B. Fuller, A Fast Flexible Ink-Jet Printing Method for Patterning Networks of Neurons in Culture, M.S. thesis, MIT (2003)

    Neil Gershenfeld,
    The Coming Revolution on Your Desktop: From Personal Computers to Personal Fabrication, Basic Books (2005)

    Timothy Gorton,
    Tangible Toolkits for Reflective Systems Modeling, M.S. thesis, MIT (2003)

    Saul Griffith, Growing Machines, Ph.D. thesis, MIT (2004)

    K. Hamad-Schifferli, in Encyclopedia of Nanoscience and Nanotechnology, edited by J. A. Schwarz, C. Contescu and K. Putyera (Marcel Dekker, New York, 2003)

    K. Hamad-Schifferli, DNA Hybridization, Electronic Control, in Encyclopedia of Nanoscience and Nanotechnology, edited by J. A. Schwarz, C. Contescu and K. Putyera (Marcel Dekker, New York, 2004).

    Matthew Hancher, A Motor Control Framework for Many-Axis Interactive Robots, M.S. thesis, MIT (2003)

    F. Impens, Fine-Grained Fault-Tolerance: Reliability as a Fungible Resource, M.S. thesis, MIT (2004)

    Daniel Kornhauser, Designing a Craft Computing Environment for Non-Industrial Settings, M.S. thesis, MIT (2002)

    Murali Kota,
    An Approach to Bridging Atom Optics and Bulk Spin Quatum Computation, Ph.D. thesis, MIT (2003)

    Che King Leo,
    Contact and Free-Gesture Tracking for Large Interactive Surfaces , M.S. thesis , MIT (2002)

    S. Daniel Lovell,
    A System for Real-Time Gesture Recognition and
    Classification of Coordinated Motion, M.S. Thesis, MIT (2005)

    S. Levy-Tzedek, Biological Detection by Means of Mass Reduction in a Suspended Microchannel Resonator, M.S. thesis, MIT (2004)

    Ji Li, Improving Application-level Network Services with Regions , M.S. thesis, MIT (2003)

    Ji Li, Agent Organization in the Knowledge Plane, Ph.D. thesis, MIT (2008)

    J. Lifton, Pushpin Computing: a Platform for Distributed Sensor
    Networks, M.S. thesis, MIT (2002)

    Yanni Loukissas, Rulebuilding: Exploring Design Worlds through End-Use Programming, M.S. thesis, MIT (2003)

    Christopher Lyon,
    Encouraging Innovation by Engineering the Learning Curve , M.S. thesis, MIT (2003)

    H. Ma and A. Slocum, 
    A Mechanism for Creating Variable Nanometer Gaps, in the Proceedings of the 2006 American Society for Precision Engineering Annual Meeting, October 15-20, Monterey, CA (2006)

    Yael Maguire,
    Scalable Electromagnetic Microstructure Instrumentation, Ph.D. thesis, MIT (2004)

    Micah O’Halloran, A Clock-Based Analog Memory Element for Integrated Circuits, M.S. thesis, MIT (2002)

    Amon Millner,
    Hook-ups: How Youth Learn Through Creating Physical Computer Interfaces, M.S. thesis, MIT (2005)

    A. Millner and S. Daily, Creating an Educational Ecosystem for Design, Personal Fabrication, and Invention, in Communities of Practice: Creating Learning Environments for Educators, C. Kimble and P. Hildreth, eds (Information Age Publishing, Charlotte, NC, 2008)

    Sunho Park,
    Control of Oligonucleotide Conformation on Nanoparticle Surfaces for Nanoscale Heat Transfer Study, M.S. thesis, MIT (2004)

    C.E. Pearson,
    Theory and Application of Planar Ion Traps, M.S. Thesis, MIT (2006)

    G.A. Popescu, P. Kunzler, and N. Gershenfeld, Digital Printing of Digital Materials, DF 2006 International Conference on Digital Fabrication Technologies, Denver, Colorado (2006)

    G.A. Popescu, N. Gershenfeld, and T. Mahale,
    Digital Materials for Digital Printing, DF 2006 International Conference on Digital Fabrication Technologies, Denver, Colorado (2006)

    Ben Recht, Convex Modeling with Priors, Ph.D. Thesis, MIT (2006)

    M. Resnick,
    Computer as Paintbrush: Technology, Play, and the Creative Society, in Play = Learning: How play motivates and enhances children's cognitive and social-emotional growth, D. Singer, R. Golikoff, K. Hirsh-Pasek (eds.), Oxford University Press (2006)

    Lawrence Sass, 
    Wood Frame Grammar: CAD scripting a wood frame house, CAAD Futures Conference, Vienna (2005)

    L. Sass and M. Botha,
    The Instant House: A Digital Fabrication System for Design Model and Full Scale Wood Frame Housing, IS&T Digital Fabrication Conference, Denver, Colorado (2006)

    Maxim Shusteff, A Microfabricated Hollow Cantilever Sensor for Sub-nanoliter Thermal Measurements, M.S. thesis, MIT (2003).

    A. Slocum, S. Awtar, A. Elmouelhi, M. Graham, P. Willoughby, "Paths-to-Peace, A New Method for Teaching Design and Manufacturing", 2nd International Conference on Open Collaborative Design for Sustainable Innovation, Bangalore, India, 2002

    Casey Smith,
    Material Design for a Robotic Arts Studio, M.S. thesis, MIT (2002)

    Alexander Sprunt and Alexander Slocum, "Fracture fabrication of single crystal silicon nanosurfaces",
    EUSPEN 5th International Conference, Vol. 1., pp. 73-76 (2005)

    Matthias Steffen,
    A Prototype Quantum Computer Using Nuclear Spins in Liquid Solution, Ph.D. thesis, MIT (2003)

    W.D. Stiehl, L. Lalla, and C. Breazeal,
    A Somatic Alphabet Approach to Sensitive Skin, Proceedings of the ICRA (2004)

    Amy Sun,
    Field Fabrication of Solar-Thermal Powered Steam Turbines for Generation of Mechanical Power, M.S. Thesis, MIT 2006

    Kie-Moon Sung, David W. Mosley, Beau R. Peelle, Shuguang Zhang and Joseph M. Jacobson,
    Nanopearls: A New Synthetic Approach Towards Creating Monofunctionalized Building Blocks for Programmable Biochemical Nanocrystal Linear Sequences, in Proceedings Foundations of Nanoscience, Snowbird, UT, April 21-23, p. 105 (2004).

    Russell L Tedrake,
    Applied Optimal Control for Dynamically Stable Legged Locomotion, Ph.D. thesis, MIT (2004)

    B. Vigoda, Analog Logic: Continuous-Time Analog Circuits for Statistical Signal Processing, Ph.D. thesis, MIT (2003)

    H. Yang, 
    A Time-Based Energy-Efficient Analog-to-Digital Converter, Ph.D. thesis, MIT (2006)

    Steve Yang,
    Self-Assembly of Surfactant-like Amphiphilic Peptides made of Natural Amino Acids, Ph.D. thesis, MIT (2004)

    Oren Zuckerman,
    System Blocks: Learning about Dynamic Behavior through Hands-on Modeling and Simulation, M.S. thesis, MIT (2004)

  2. What Web site or other Internet site have you created?

    http://cba.mit.edu/
    Primary CBA site


    http://fab.cba.mit.edu/

    CBA server for fab classes/labs/facilities
  3.  What other specific products (databases, physical collections, educational aids, software, instruments, or the like) have you developed?

    A significant constraint on the use of the fabrication tools in both CBA's on-campus facilities and its field fab labs has been limiting assumptions about their applications that are imposed by the available CAM software. Therefore, in support of the research program
    a universal CAM tool was written (cam.py) that can currently input SVG, 2D and 3D DXF, Gerber, Excellon, and JPEG design files, and produce output toolpaths for an NC mill, machining center, vinyl cutter, laser cutter, waterjet cutter, excimer micromaching center, and focused ion-beam writer:


    This was followed by a universal design tool, cad.py, based on describing objects with algorithms, represented them by mathematical satisfiability strings, and solving these on a lattice:

    Another program (site.py) was written to support project documentation and process knowledge sharing within and across the fab labs, going beyond collaborative Web-site editing to provide in the field on-campus capabilities by exposing a restricted command shell available through a Web interface:

    This has grown into a Web interface to a distributed version control and content management system (siteserver.py):

    These capabilties are being merged in a third software generation, "kokompe" (named after a district with mechanical repair shops in Ghana), that provides modular thin-client user interfaces communicating with an engineering workflow server for modeling, rendering, toolpath generation, machine control, and distributed project management.

    An example of the use of the fab lab hardware and software is the "Scratch Patches," functional building blocks containing embedded sensing, computing, and communications that are made from laser-cut tiles with laminated vinyl-cut circuits, allowing kids to assemble custom devices such as computer game controllers.

    [Millner, 2005].