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Wednesday, September 14, 2011

Envisioning the Future

          Backed by the microchip manufacturer Intel, first generation catoms, measuring 4.4 centimetres in diameter and 3.6 centimetres in height have already been created. The goal is to eventually produce catoms that are one or two millimetres in diameter-small enough to produce convincing replicas. It's not just a problem of building tiny robots, but figuring out how to power them, to get them to stick together and to coordinate and control millions or billions of them. These catoms, which are ringed by several electromagnets, are able to move around each other to form a variety of shapes containing rudimentary processors and drawing electricity from a board that they rest upon. So far only four catoms have been operated together. The plan though is to have thousands of them moving around each other to form whatever shape is desired and to change colour, also as required. 

Five years from now, the DPR researchers expect to have working ensembles of catoms that are close to spherical in shape. These catoms still will be large enough that no one will confuse a replica with the real thing (for that, catoms will probably have to shrink to less than a millimetre in diameter). But the catoms will be sufficiently robust that researchers can experiment with a variety of shapes, test hypotheses about ensemble behaviour, and begin to envision where the technology might lead within a decade or two.
While the potential applications of dynamic physical rendering are exciting, the work being done at Intel Research Pittsburgh and Carnegie Mellon University has broader implications. At its core, the research involves learning to design, power, program and control a densely packed set of microprocessors. These are similar to the key challenges facing the computer industry today. As a result, the DPR research is likely to produce new insights and technologies that could influence the future of computing and communications.
If, in 1960, someone had suggested that one day you could buy a million transistors for a penny, the prediction would have seemed outlandish. But today Intel sells transistors for less than a micro cent, thanks to the continuing technology advances predicted by Moore's Law. It's not unreasonable to predict that one day far in the future; it may be possible to buy a million catoms for a penny.
But dynamic physical rendering could become viable long before Moore's Law drives down the cost of a catom to a micro cent. Even if catoms could be produced for a dollar each, some visualization applications might be economically viable. Certain other applications, such as programmable antennas, could be attractive even if a catom sold for tens or hundreds of dollars.
Whatever the cost, building catoms that are one millimetre in diameter-small enough to create convincing replicas-will be a difficult engineering challenge. But given current industry knowledge and the state of the art of silicon technology, it is not outside the realm of possibility. The challenge lies less in developing new technology than in bringing together a number of research areas in which the industry has made tremendous technical progress in the last decade.

Application of Claytronics/DPR


          The potential applications of dynamic physical rendering are limited only by the imagination. Following are a few of the possibilities:
> Medicine: A replica of your physician could appear in your living room and perform an exam. The virtual doctor would precisely mimic the shape, appearance and movements of your "real" doctor, who is performing the actual work from a remote office.

> Disaster relief: Human replicas could serve as stand-ins for medical personnel, firefighters, or disaster relief workers. Objects made of programmable matter could be used to perform hazardous work and could morph into different shapes to serve multiple purposes. A fire hose could become a shovel, a ladder could be transformed into a stretcher.
 
Entertainment: A football game, ice skating competition or other sporting event could be replicated in miniature on your coffee table. A movie could be recreated in your living room, and you could insert yourself into the role of one of the actors.

3D physical modeling: Physical replicas could replace 3D computer models, which can only be viewed in two dimensions and must be accessed through a keyboard and mouse. Using claytronics, you could reshape or resize a model car or home with your hands, as if you were working with modeling clay. As you manipulated the model directly, aided by embedded software that's similar to the drawing tools found in office software programs, the appropriate computations would be carried out automatically. You would not have to work at a computer at all; you would simply work with the model. Using claytronics, multiple people at different locations could work on the same model. As a person at one location manipulated the model, it would be modified at every location. 

Capabilities of Catoms



While catoms will be simple in design, each will have four capabilities:
Ø  Computation: Researchers believe that catoms could take advantage of existing microprocessor technology. Given that some modern microprocessor cores are now under a square millimetre, they believe that a reasonable amount of computational capacity should fit on the several square millimetres of surface area potentially available in a 2mm-diameter catom.
Ø  Motion: Although they will move, catoms will have no moving parts. This will enable them to form connections much more rapidly than traditional microrobots, and it will make them easier to manufacture in high volume. Catoms will bind to one another and move via electromagnetic or electrostatic forces, depending on the catom size.
              Imagine a catom that is close to spherical in shape, and whose perimeter is covered by small electromagnets. A catom will move itself around by energizing a particular magnet and cooperating with a neighbouring catom to do the same, drawing the pair together. If both catoms are free, they will spin equally about their axes, but if one catom is held rigid by links to its neighbours, the other will swing around the first, rolling across the fixed catom's surface and into a new position. Electrostatic actuation will be required once catom sizes shrink to less than a millimetre or two. The process will be essentially the same, but rather than electromagnets, the perimeter of the catom will be covered with conductive plates. By selectively applying electric charges to the plates, each catom will be able to move relative to its neighbours.
Ø  Power: Catoms must be able to draw power without having to rely on a bulky battery or a wired connection. Under a novel resistor-network design the researchers have developed, only a few catoms must be connected in order for the entire ensemble to draw power. When connected catoms are energized, this triggers active routing algorithms which distribute power throughout the ensemble.
Ø  Communications: Communications is perhaps the biggest challenge that researchers face in designing catoms. An ensemble could contain millions or billions of catoms, and because of the way in which they pack, there could be as many as six axes of interconnection.
            Another unique feature of catom networks is that catoms are homogeneous. Thus, unlike cell phones or other communications devices, the identity of an individual catom is sometimes (but not always) unimportant. An application is more likely to care about routing a message to the catoms comprising a specific physical part of an ensemble (for instance, the catoms comprising a "hand") rather than sending the same message to specific catoms based on their serial numbers. Furthermore, catoms may be in motion periodically, as the shape of the ensemble changes.
Ø  Creating the replica:   At a high level, there are two steps :
·         Capturing a moving, three-dimensional image and
·         rendering it as a physical object.
Researchers at Carnegie Mellon University also are exploring 3D image capture, in the Virtualized Reality project. They have developed technology that points a set of cameras at an event and enables the viewer to virtually fly around and watch the event from a variety of positions. The DPR researchers believe a similar approach could be used to capture 3D scenes for use in creating physical, moving 3D replicas.

Replicas will be created from Catoms. Catoms can be formed into different shapes, and it can change color, through light-emitting diodes on its surface. Embedded photo cells will enable it to sense light, so that a human replica can "see." Catoms might even simulate the texture of the person or object being replicated. A replica will have computing capabilities, but these will be accessed through touch, voice, or another natural interface rather than a keyboard or mouse. Catoms will be as close to spherical as possible to support multiple packing densities.

Tuesday, September 13, 2011

SOFTWARE


Distributed Computing in Claytronics
In a domain of research defined by many of the greatest challenges facing computer scientists and roboticists today, perhaps none is greater than the creation of algorithms and programming language to organize the actions of millions of sub-millimetre scale catoms in a claytronics ensemble.
As a consequence, the research scientists and engineers of the Carnegie Mellon-Intel Claytronics Research Program have formulated a very broad-based and in-depth research program to develop a complete structure of software resources for the creation and operation of the densely distributed network of robotic nodes in a claytronic matrix.
A notable characteristic of a claytronic matrix is its huge concentration of computational power within a small space.  For example, an ensemble of catoms with a physical volume of one cubic meter could contain 1 billion catoms.  Computing in parallel, these tiny robots would provide unprecedented computing capacity within a space not much larger than a standard packing container.  This arrangement of computing capacity creates a challenging new programming environment for authors of software.
A representation of a matrix of approximately 20,000 catoms can be seen in the left frame of the illustration at the top of this column. Because of its vast number of individual computing nodes, the matrix invites comparison with the worldwide reservoir of computing resources connected through the Internet, a medium that not only distributes data around the globe but also enables nodes on the network to share work from remote locations.  The physical concentration of millions of computing nodes in the small space of a claytronic ensemble thus suggests for it the metaphor of an Internet that sits on a desk.
2.2.2  An Internet in a Box
Comparison with the Internet, however, does not represent much of the novel complexity of a claytronic ensemble.  For example, a matrix of catoms will not have wires and unique addresses -- which in cyberspace provide fixed paths on which data travels between computers.  Without wires to tether them, the atomized nodes of a claytronic matrix will operate in a state of constant flux. The consequences of computing in a network without wires and addresses for individual nodes are significant and largely unfamiliar to the current operations of network technology.

Languages to program a matrix require a more abbreviated syntax and style of command than the lengthy instructions that widely used network languages such as C++ and Java employ when translating data for computers linked to the Internet.  Such widely used programming languages work in a network environment where paths between computing nodes can be clearly flagged for the transmission of instructions while the computers remain under the control of individual operators and function with a high degree of independence behind their links to the network. 

In contrast to that tightly linked programming environment of multi-functional machines, where C++, Java and similar languages evolved, a claytronic matrix presents a software developer with a highly organized, single-purpose, densely concentrated and physically dynamic network of unwired nodes that create connections by rotating contacts with the closest neighbours.  The architecture of this programming realm requires not only instructions that move packets of data through unstable channels.  Matrix software must also actuate the constant change in the physical locations of the anonymous nodes while they are transferring the data through the network.

For the Nodes, It’s All about Cooperation
In this environment, the processes of each individual catom must be entirely dedicated to the operational goal of the matrix – which is the formation of dynamic, 3-dimensional shapes.  Yet, given the vast number of nodes, the matrix cannot dedicate its global resources to the micro-management of each catom.  Thus, every catom must achieve a state of self-actuation in cooperation with its immediate neighbors, and that modality of local cooperation must radiate through the matrix.

Software language for the matrix must convey concise statements of high-level commands in order to be universally distributed.  For this purpose, it must possess an economy of syntax that is uncommon among software languages.  In place of detailed commands for individual nodes, it must state the conditions toward which the nodes will direct their motion in local groups.  In this way, catoms will organize collective actions that gravitate toward the higher-level goals of the ensemble. 

A Seamless Ensemble of Form and Functionality
By providing a design to focus constructive rearrangements of individual nodes, software for the matrix will motivate local cooperation among groups of catoms.  This protocol reflects a seamless union between form and functionality in the actuation of catoms.  It also underscores the opportunity for high levels of creativity in the design of software for the matrix environment, which manipulates the physical architecture of this robotic medium while directing information through it.

In a hexagonal stacking arrangement, for example, rows of catoms in one layer rest within the slight concavities of catom layers above and below them.  That placement gives each catom direct communication with as many as 12 other catoms.  Such dynamic groupings provide the stage upon which to program catom motion within local areas of the matrix.  Such collective actuation will transform the claytronic matrix into the realistic representations of original objects.

The Research Program
In the Carnegie Mellon-Intel Claytronics Software Lab, researchers address several areas of software development, which are described in this section of the website.

Programming Languages

Researchers in the Claytronics project have also created Meld and LDP.  These new languages for declarative programming provide compact linguistic structures for cooperative management of the motion of millions of modules in a matrix.  The center panel above shows a simulation of Meld in which modules in the matrix have been instructed with a very few lines of highly condensed code to swarm toward a target.
Integrated Debugging

In directing the work of the thousands to millions of individual computing devices in an ensemble, claytronics research also anticipates the inevitability of performance errors and system dysfunctions.  Such an intense computational environment requires a comparably dynamic and self-directed process for identifying and debugging errors in the execution of programs.  One result is a program known as Distributed Watch Points, represented in the snapshot in the right panel below.
Shape Sculpting
The team's extensive work on catom motion, collective actuation and hierarchical motion planning addresses the need for algorithms that convert groups of catoms into primary structures for building dynamic, 3-dimensional representations.   Such structures work in a way that can be compared to the muscles, bones and tissues of organic systems.  In claytronics, this special class of algorithms will enable the matrix to work with templates suitable to the representations it renders.  In this aspect of claytronics development, researchers develop algorithms that will give structural strength and fluid movement to dynamic forms.  Snapshots from the simulation of these studies can be seen in the right-side panel at the top of this column and in the left-side panel below.

Localization
The team’s software researchers are also creating algorithms that enable catoms to localize their positions among thousands to millions of other catoms in an ensemble.  This relational knowledge of individual catoms to the whole matrix is fundamental to the organization and management of catom groups and the formation of cohesive and fluid shapes throughout the matrix.  A pictorial context for examining the dynamics of localization is represented by the snapshot of the elephant simulated in the center panel of images below.

Dynamic Simulation
As a first step in developing software to program a claytronic ensemble, the team created DPR-Simulator, a tool that permits researchers to model, test and visualize the behavior of catoms.  The simulator creates a world in which catoms take on the characteristics that researchers wish to observe.  A Linux-based modeling tool, DPRSim can be downloaded from the website of the Intel Pittsburgh Lab.

The simulated world of DPRSim manifests characteristics that are crucial to understanding the real-time performance of claytronic ensembles.  Most important, the activities of catoms in the simulator are governed by laws of the physical universe.  Thus simulated catoms reflect the natural effects of gravity, electrical and magnetic forces and other phenomena that will determine the behavior of these devices in reality.  DPRSim also provides a visual display that allows researchers to observe the behavior of groups of catoms.  In this context, DPRSim allows researchers to model conditions under which they wish to test actions of catoms.  At the top and bottom of this column, images present snapshots from simulations of programs generated through DPRSim.  Videos from simulations can be seen on other pages of this site

HARDWARE



            At the current stage of design, claytronics hardware operates from macroscale designs with devices that are much larger than the tiny modular robots that set the goals of this engineering research.  Such devices are designed to test concepts for sub-millimeter scale modules and to elucidate crucial effects of the physical and electrical forces that affect nanoscale robots.
Planar catoms test the concept of motion without moving parts and the design of force effectors that create cooperative motion within ensembles of modular robots.
Electrostatic latches model a new system of binding and releasing the connection between modular robots, a connection that creates motion and transfers power and data while employing a small factor of a powerful force.
Stochastic Catoms integrate random motion with global objectives communicated in simple computer language to form predetermined patterns, using a natural force to actuate a simple device, one that cooperates with other small helium catoms to fulfill a set of unique instructions.
Giant Helium Catoms provide a larger-than-life, lighter-than-air platform to explore the relation of forces when electrostatics has a greater effect than gravity on a robotic device, an effect simulated with a modular robot designed for self-construction of macro-scale structures.
Cubes employ electrostatic latches to demonstrate the functionality of a device that could be used in a system of lattice-style self-assembly at both the macro and nano-scale.
            Each section devoted to an individual hardware project provides an overview of the basic functionality of the device and its relationship to the study of claytronics. As these creative systems have evolved in the Carnegie Mellon-Intel Claytronics Hardware Lab, they have prepared the path for development of a millimeter scale module that will represent the creation of a self-actuating catom - a device that can compute, move, and communicate - at the nano-scale.

2.1.1  Millimetre Scale Catoms -
Realizing high-resolution applications that Claytronics offers requires catoms that are in the order of millimetres. In this work, we propose millimetre-scale catoms that are electrostatically actuated and self-contained. As a simplified approach we are trying to build cylindrical catoms instead of spheres.
The millimetre scale catom consists of a tube and a High voltage CMOS die attached inside the tube. The tubes are fabricated as double-layer planar structures in 2D using standard photolithography. The difference in thermal stress created in the layers during the fabrication processes causes the 2D structures to bend into a 3D tubes upon release from the substrate. The tubes have electrodes for power transfer and actuation on the perimeter.
The high voltage CMOS die is fabricated separately and is manually wire bonded to the tube before release. The chip includes an AC-DC converter, a storage capacitor, a simple logic unit, and output buffers.

The catom moves on a power grid (the stator) that contains rails which carry high voltage AC signals. Through capacitive coupling, an AC signal is generated on the coupling electrodes of the tube, which is then converted to DC power by the chip. The powered chip then generates voltage on the actuation electrodes sequentially, creating electric fields that push the tube forward.


1.1.2    Cubes
A lattice-style modular robot, the 22-cubic-centimeter Cube, which has been developed in the Carnegie Mellon-Intel Claytronics Research Program, provides a base of actuation for the electrostatic latch that has also been engineered as part of this program.  The Cube (pictured below, right) also models the primary building block in a hypothetical system for robotic self-assembly that could be used for modular construction and employ Cubes that are larger or smaller in scale than the pictured device.

  The design of a cube, which resembles a box with starbursts flowering from six sides, emphasizes several performance criteria: accurate and fast engagement, facile release and firm, strong adhesion while Cube latches clasps one module to another.  Its geometry enables reliable coupling of modules, a strong binding electrostatic force and close spacing of modules within an ensemble to create structural stability.
Designed to project angular motion from the faces of its box-like shape, the Cube extends and contracts six electrostatic latching devices on stem assemblies.  By this mechanism, the latches of a Cube integrate with latches on adjacent Cubes for construction of larger shapes.
With extension and retraction of stem-drive arms that carry the latches, the module achieves motion, exchanges power and communicates with other Cubes in a matrix that contains many of these devices.  Combining these forces of motion, attachment and data coupling, Cubes demonstrate a potential to create intricate forms from meta-modules or ensembles that consist of much greater numbers of Cubes; numbers determined by the scale of Cubes employed in an ensemble of self-construction.
To create motion for a Cube in a matrix of many cubes, a direct-current motor inside the Cube's central frame actuates expansion and contraction of electrostatic latches fixed to the ends of independent worm-drive assemblies.  Housed in individual tubes, the assemblies provide arms to support the motion of latches from six sides of the central frame.  Linear motion enables the Cube to exploit considerable lateral flexibility for forming shapes within a matrix.  The Cube measures 22 cm between faces when fully contracted and 44 cm when fully expanded.
The worm-drive assembly extends the face of one cube to create contact with the face of an adjacent cube.  The electrodes on each face create one-half of a capacitor.  When the two "genderless," star-shaped faces of adjacent Cubes integrate their combs, they complete a capacitor and form an electrostatic couple from the contact of electrodes, which binds the faces as a completed latch.
The capacitive couple, which forms the electrostatic latch, provides within an ensemble of Cubes not only adhesion and structural stability but also the transmission of power and communication.  In a meta-module of many cubes, power would move in discrete packets rather than as a continuous current, in a mode similar to data moving through a network in discrete packets of bytes that reassemble into larger packages of information at the point of delivery.  This packet delivery of energy would enable the meta-module or ensemble to move power from cubes that have a surplus to others that require more of it.


Cubes reconfigure by expanding the connected faces of two neighbouring modules so that one is pushed one block length across the assembly.  Then by contracting its extended arm, it pulls the next module forward.  Such motion within a meta-module consisting of sufficiently large numbers of cubes could form any conceivable shape.
This micro-electro-mechanical device thus presents a model for a type of robotic self-assembly of complex structures at both macro and micro scales.
1.1.3                Powering Catoms with Magnetic Resonant Coupling
As a potential means for providing power to catoms without using electrical connections, they have experimentally demonstrated wireless power transfer via magnetic resonant coupling is in a system with a large source coil and either one or two small receivers. Resonance between source and load coils is achieved with lumped capacitors terminating the coils.
They have developed a circuit model to describe the system with a single receiver, and extended it to describe the system with two receivers. With parameter values chosen to obtain good fits, the circuit models yield transfer frequency responses that are in good agreement with experimental measurements over a range of frequencies that span the resonance. Resonant frequency splitting is observed experimentally and described theoretically for the multiple receiver system.
In the single receiver system at resonance, more than 50% of the power that is supplied by the actual source is delivered to the load. In a multiple receiver system, a means for tracking frequency shifts and continuously retuning the lumped capacitances that terminate each receiver coil so as to maximize efficiency is a key issue for future work.
1.1.4                Planar Catoms
   The self-actuating, cylinder-shaped planar catom tests concepts of motion, power distribution, data transfer and communication that will be eventually incorporated into ensembles of nano-scale robots.  It provides a testbed for the architecture of micro-electro-mechanical systems for self-actuation in modular robotic devices. Employing magnetic force to generate motion, its operations as a research instrument build a bridge to a scale of engineering that will make it possible to manufacture self-actuating nano-system devices.


The planar catom is approximately 45 times larger in diameter than the millimetre scale catom for which its work is a bigger-than-life prototype.  It operates on a two-dimensional plane in small groups of two to seven modules in order to allow researchers to understand how micro-electro-mechanical devices can move and communicate at a scale that humans cannot yet readily perceive -- or imagine.  It forms a bridge into this realm across the evolving design of a sophisticated electro-magnetic system whose features have followed a path of trail and error as the CMU-Intel Claytronics Research Team has tested the concept of a robot that moves without moving parts. 
In its brief history of demonstrating motion without moving parts, the planar catom has evolved through eight versions.  It began life as a concept vehicle engineered with catalog-sourced hardware.  It has become a custom-designed electronic and magnetic system that carries a complete control package aboard its module. 
Weighing 100 grams, Planar Catom V8, shown in the picture here, presents for view its stack of control and magnet-sensor rings.  Its solid state electronic controls ride at the top of the stack.  An individual control ring is dedicated to each of the two rings of magnet sensors, which ride at the base of the module.  Two thin threaded rods extend like lateral girders from top to bottom through the outside edge to brace the rings.  A central connector stack carries circuits between control and magnet rings, enabling easier handling and maintenance of components while also providing internal alignment and stability along the cylinder's axis.
At the base of the planar catom, the two heavier electro-magnet rings, which comprise the motor for the device, also add stability.   To create motion, the magnet rings exchange the attraction and repulsion of electromagnetic force with magnet rings on adjacent catoms.  From this conversion of electrical to kinetic energy, the module achieves a turning motion to model the spherical rotation of millimeter-scale catoms.
Pictured in a top view (left, below), two magnet rings from Planar Catom V7 display the arrangement of their 12 magnets around individual driver boards and the coil design for horseshoe magnets introduced with Version 6 and then upgraded in versions 7 and 8.




 The magnets are arranged in the containment ring as the straightedge faces of a 12-sided polygon seated in the acrylic plate that holds them in place.  The horseshoe magnets feature 39AWG magnet wire wrapped around AISI 1010 steel cores, components selected to balance machinable metal and flux-saturation density.
Replacing barrel-shaped, round-face magnets in Planar Catom Versions 1-5, the horseshoe magnet was adopted to boost magnet strength and create a wider footprint.  It also represents an evolution of the use of flat-surface magnets, which were introduced in Planar Catom Version 5.  Flat surfaces prove to be more efficient for contact than round-face magnets.

Economy in the design of the controls also makes more room for the rest of the robust package of electronics that operate the module. The picture to the right displays a planar catom controller ring with light emitting diodes (LEDs) arranged around its perimeter.  This board directs the two magnet driver boards embedded in the magnet rings, as shown in the image above.
The custom design of the electronics achieves a very high level of capacity to guide the module's performance.  Built with the smallest components commercially available, each controller board contains 5 layers of embedded microcircuits on 45 mm diameter acrylic boards.  At this density of circuit design, each of the two controller rings provides approximately 40 times the embedded instrumentation of a standard robotics controller package in 2/5th the space. The resulting capacity of its boards enables the module to carry on board all devices needed to manage its firmware, drivers and 24 magnets. 
A more typical robotics servo controller would carry a microprocessor, motors, servos and other devices on one side of a 50 mm x 75 mm board embedded with two layers of microcircuits. While building planar catoms to investigate a customized actuation system that creates motion without moving parts, the design team also achieved the complementary objective of constructing a robust, self-contained modular robot.
Another component of this robust electronic system is shown in the picture below of a Planar Catom Infrared Communication Board. On this device, the Infrared Data (IrDA) transmitters and receivers are separately multiplexed to transmit and receive signals on separate channels, allowing fast, simultaneous transmission on all channels.  These global communication features anticipate the necessity of debugging and reprogramming large ensembles of catoms.
The engineering goal for these components is a system that supports cooperative behaviour among nanoscale robotic modules.  This concept of machine behaviour is one in which the primary devices direct their own motion toward a common goal by employing functionality that focuses every element of design on the requirements of the ensemble rather than on those of the individual robot.  The engineering design thus adheres to the ensemble axiom by incorporating in these devices only those functions that advance the functionality of the ensemble.
2.1.5  Electrostatic Latches
A simple and robust inter-module latch is possibly the most important component of a modular robotic system. The electrostatic latch pictured below was developed as part of the Carnegie Mellon-Intel Claytronics Research Project.  It incorporates many innovative features into a simple, robust device for attaching adjacent modules to each other in a lattice-style robotic system.  These features include a parallel plate capacitor constructed from flexible electrodes of aluminium foil and dielectric film to create an adhesion force from electrostatic pressure. Its physical alignment of electrodes also enables the latch to engage a mechanical shear force that strengthens its holding force.





 The electrodes that form the latch fit into "genderless" faces constructed as star-shaped plastic frames carried by each module.  In the design of the circuits, each electrode functions as one-half of a complete capacitor.  A latch forms when the faces of two adjacent modules come together and create an electrostatic field between the flexible electrodes.
Each star-shaped face supports passive self-alignment of the link with a 45-degree blade angle at the top of each comb on the face.  The design also supports easy disengagement with a five-degree release angle along the vertical lines of the faces.
The parallel alignment of the electrodes in forming the complete capacitor plate introduces a shear force - or friction - that strengthens the binding of the latch.  Once formed, the latch requires almost zero static power to maintain its holding force.  Additionally, the presence of multiple circuits among the electrodes provides the latch with simultaneous capacity also to exchange power and communicate data between modules. These features make the device suitable for lattice-style robots in both nanotechnology (micro-scale) and macroscale applications. 
In its electrical design, the electrostatic latch uses the closely spaced plates of a parallel capacitor, which generate an electrostatic force to attract each other when the capacitor is charged.  After the latch closes, residual charge maintains the latch indefinitely.  A thin dielectric film on each conductive plate provides insulation.
Employing capacitive coupling, the latch adheres with a force of 0.6 N/cm2 while requiring almost zero static power to maintain the force after the latch forms.  A specific degree of flexibility in the electrodes maximizes the mutual coupling of electrodes. Electrodes that are too rigid or too flexible do not provide an adequate level of latch performance.
Moreover, the electrodes create multiple circuits, which allow transmission of power and data for communication between modules.  This design serves several functions within the robotic module and enables a level of efficiency that reduces requirements for total weight, volume and complexity.  This design feature thus yields simpler paths to performance and scaling goals in robotic modules.
The factor that enables electrostatic adhesion to be effective at the macroscale is an interface for the electric field that also creates a shear force from mechanical friction.   A combination of electrostatic and shear forces results from the alignment. Currently, the electrostatic latch is being tested on a modular Cube that is 28 cm on a side.
2.1.6  Stochastic Catoms
A concept being tested in the Carnegie Mellon-Intel Claytronics Research Project is the use of stochastic reconfiguration in ensembles of modular robots.  In this mode of reconfiguration, the module relies on random motion and follows unmapped paths to gain in the ensemble a position where it can determine its exact location and contribute its form to the overall structure.
Depending upon the scale of the device, actuation of the module's motion can be created with various sources of energy, including currents of air, electrostatics or, in the case of a study of the phenomenon during Andrew's Leap, Carnegie Mellon's summer enrichment program, the propelling motion of high school students throwing helium-filled balloons. 
From such forces, a module derives an initially incoherent motion that causes random contacts with other modules. In these contacts, the module evaluates the appropriateness of forming a connection with the other module.  The module makes its decision by evaluating the relation of its form in the instance of the contact location to the ensemble's overall goal for a predetermined shape.  Based on this evaluation, the module either forms a bond or continues in motion.
To demonstrate the applicability of stochastic reconfiguration to modular robots, the Andrew's Leap students constructed an ensemble of Mylar balloons in the shape of cubes, each approximately 1/2 meter on a side.  They also created a lightweight electronic module to support each catom's functionality as well as simple latches for the faces of each cube to provide a means of data exchange and attachment among catoms.  To create buoyancy, each catom was filled with helium. 
Computations within the electronic module follow a simple program, known as a graph grammar, which enables each stochastic catom independently to determine its location in relation to other catoms in the ensemble - and in relation to a predetermined shape into which the catoms locate their positions from random motion
Localizing its position while in contact with other catoms, a catom either engages its electrostatic latch in order to bind to an adjacent robot or signals for separation and further stochastic motion until it identifies a location where it will contribute to the desired global shape.
As a type of swarm behavior conceived for nano-scale robots, stochastic motion among catoms would draw upon mathematical probability whose effective potential to shape forms would increase with greater numbers of smaller-scale modules.
2.1.7  Giant Helium Catoms
A Giant Helium Catom (GHC) measures eight cubic meters when its light Mylar skin fills with helium to acquire a lifting force of approximately 5.6 kilograms.  This lift is necessary to elevate a frame of carbon fiber rods and plastic joints, which contains the balloon and carries electronic sensors and a communication package to actuate the catom's motion and engage it with other GHCs.  The roughly square balloon is constructed with edge dimensions of approximately 1.9 meters from 4 meter x 1 meter sheets of Mylar.  Each balloon uses four sheets of this material.
The Giant Helium Catom provides researchers a macroscale instrument to investigate physical forces that affect microscale devices.  The GHC was designed to approximate the relationship between a near-zero-mass (or weightless) particle and the force of electro-magnetic fields spread across the surface of such particles.  Such studies are needed to understand the influence of surface tensions on the engineering of interfaces for nanoscale devices.
In addition to its role as a test-bed for nanoscale surface tensions, the great helium catom also offers a prototype design for a low-mass system of robotic self-assembly that can be used at life-scale in solar system travel.  Because of its very low mass, it was conceived also as a macroscale construction system for delivery by space craft. Such a system would deploy dwellings and workstations on the Moon and the planet Mars in advance of astronauts who would occupy the pre-constructed stations for long-term exploration and interplanetary travel.   
On each face, the GHC cube carries a novel electrostatic latching system that enables the device to move across the faces of other catoms and to communicate with them. The design for this latch system centres on a thin aluminium foil flap across each of the 12 edges of the Mylar cube.  This is essentially a square that crosses each of the catom's edges on a diagonal in order to create two triangular flaps lying at a right angle to each other against the two adjacent surfaces of the catom. With this arrangement, each surface of the catom has four triangular flaps with peaks pointed toward the centre of the face.
Among the six faces, the triangular flaps provide each catom with the means to form an electrostatic latch with another cube from 24 positions - providing the cubes with a capacity to move at right angles in any direction.  In addition to motion, the latches also equip the GHC with the means to communicate across the ensemble of catoms.  In the drawing below, one Giant Helium Catom pivots across the surface of another, revealing the positions and attachments of triangular electrostatic flaps.
Two electrodes on each flap create the electrostatic forces that enable latches to form a capacitive couple between flaps on adjacent GHCs.  A dielectric material (Mylar) isolates the pair of electrodes (and electrical charges from them) on each flap to prevent their direct electrical contact.  This design enables voltage differences applied to the electrodes to accumulate charges, create electrostatic force on the flap and align with electrodes that carry an opposing charge on the flap of an adjacent GHC.
             Each flap moves independently with the assistance of a spring-loaded mechanism and a composite shape-memory alloy (SMA).  GHCs deliver power to each other using capacitive coupling with alternating current (AC).  The AC power generated at the neighbouring catom is rectified and regulated, and the resulting DC power is used for processing and other electronics on the module. A high-voltage generator creates the electrostatic force to activate the latches. 
Although the project planned to construct six giant helium catoms to simulate an ensemble, in its 3-month duration, this experiment tested this interface on two catoms.   Experience with this design provided the Carnegie Mellon-Intel Claytronics Research Project with substantial experience in the design characteristics of micro-electro-mechanical latches.

CLAYTRONICS/DPR PROJECT


The DPR project was begun at Carnegie Mellon University, spearheaded by Seth Goldstein, an Associate Professor in the Computer Science Department. The project is the brainchild of Goldstein and Todd Mowry, Director of Intel Research Pittsburgh, who first discussed the idea at a conference in 2002. Mowry wanted to improve on two-dimensional videoconferencing, and Goldstein was interested in nanotechnology. They decided to merge their interests. They determined that, by taking advantage of advances in nanoscale assembly, they might create human replicas from ensembles of tiny computing devices that could sense, move, and change color and shape, enabling more realistic videoconferencing. The same meeting environment, with people and objects, could appear at each location, in real form or as replicas. A movement or interaction at any location would be reproduced at all of them. Every meeting could be face-to-face.
What began as a novel idea has evolved into an ambitious collaboration involving almost 30 researchers. Jason Campbell, a senior researcher at Intel Research Pittsburgh, is the Principal Investigator for the DPR project. Goldstein is leading the project for Carnegie Mellon, and Mowry provides additional leadership. The project is being funded by Intel, Carnegie Mellon University, the National Science Foundation, and the Defence Advanced Research Projects Agency (DARPA).
Creation of claytronics technology is the bold objective of collaborative research between Carnegie Mellon and Intel, which combines nano-robotics and large-scale computing to create synthetic reality, a revolutionary, 3-dimensional display of information.  The vision behind this research is to provide users with tangible forms of electronic information that express the appearance and actions of original sources.
The objects created from programmable matter will be scalable to life size or larger.  They will be likewise reducible in scale. Such objects will be capable of continuous, 3-D motion.  Representations in programmable matter will offer to the end-user an experience that is indistinguishable from reality.  Claytronic representations will seem so real that users will experience the impression that they are dealing with the original object.
Claytronic emulation of the function, behaviour and appearance of individuals, organisms and objects will fully mimic reality - and fulfill a well-known criterion for artificial intelligence formulated by the visionary mathematician and computer science pioneer Alan Turing.

In 1950, in a ground-breaking article, Turing asked "Can Machines Think?"  and offered a criterion to "refute anyone who doubts that a computer can really think."  His proposal was that "if an observer cannot distinguish the responses of a programmed machine from those of a human being, the machine is said to have passed the Turing Test."
Although the Turing Test remains a robust source of discussion among those who devote their lives to artificial intelligence, philosophy and cognitive science, claytronics conceives of a technology that will surpass the Turing Test for the appearance of thought in the behaviours of a machine.
The Carnegie Mellon Intel Claytronics Research Project combines two principal paths to create technology that will represent information in dynamic, life-like 3-D forms --
♦ Engineering design and testing of modular robotic catom prototypes that will be suitable for manufacturing in mass quantities
♦ Creation of programming languages and software algorithms to control ensembles of millions of catoms
The Carnegie Mellon-Intel Claytronics Research Project addresses many unique and challenging aspects of micro-robotics engineering and distributed network computing.  It approaches these challenges with a focus fixed upon the design of the simplest feasible systems consistent with the overall goal of the reliable and robust performance of claytronic ensembles.  This approach seeks to enable claytronics technology to develop in concert with minimization of manufacturing costs and fabrication complexity. 
Reaching across the present frontier for computing and micro-electro-mechanical systems, creators of claytronics technology seek pioneering advances on two distinctive scales of building engineered systems -
♦ The scale of the extremely small, which will be embedded in the physical hardware of the sub-millimeter catom, the primary building block of claytronic ensembles, and
♦ The scale of the extremely numerous, which will be embodied in the millions of catoms that populate a claytronic ensemble.

To integrate these two scales into an engineered claytronic ensemble, the Carnegie Mellon-Intel Claytronics Research Project employs the design principle of the Ensemble Axiom. This principle of ensemble design at extreme scale pushes research toward three goals:
♦  To create the tiniest modular robots as micro-electro-mechanical systems
♦ To conceive the linguistic framework for software programming that can translate commands efficiently in densely packed networks of distributed computing, and
♦ Design program algorithms that guide the actuation of modular robots in the construction of three-dimensional objects
As one example of its application, the ensemble axiom inspires the engineering of "motion without moving parts," an application of ensemble design in planar catoms, modular robots that use electromagnetic energy to self-actuate in a mode of cooperative motion. The ensemble principle or axiom also guides the design of software.  In many robotic systems, algorithms of motion draw upon high-dimensional search or gradient-based methods of motion analysis to anticipate a module's many conceivable moves and formulate case-by-case responses. Applied to a million catoms in a claytronic ensemble, that process of control would require an impossibly large consumption of computing resources.  Programming languages for claytronics focus on simpler instructions that allow each node to analyse and respond to its immediate state without relying on omniscient top-down controls.

Introduction


We still tell our children “you can be anything when you grow up.” It’s time to start telling them “you’re going to be able to make anything…right now.” How can a material be intelligent by being made up of particle-sized machines? The idea is simple: make basic computers housed in tiny spheres that can connect to each other and rearrange themselves. Each particle, called a Claytronics atom or Catom, is less than a millimeter in diameter. With billions you could make almost any object you wanted.
Catoms, or Claytronics Atoms, are also referred to as 'programmable matter'. Catoms are described as being similar in nature to a nanomachine, but with greater power and complexity. While microscopic individually, they bond and work together on a larger scale. Catoms can change their density, energy levels, state of being, and other characteristics using thought alone.
It will take billions of micron-scale ‘claytronic atoms’ or ‘catoms’ to create computer generated artifacts as if they were the real thing, such as a self-assembling synthetic doctor coming to your house via Internet — and controlled by the real one living miles away. Or you can imagine several colleagues from around the world appearing magically in your local meeting room.
Imagine for example an LCD screen that once used turns into shows that one door on itself permanently. It’s strange, it remind a little of the principle of the film “Transformers”… Technically, catoms built by Intel are still far from having the proper scale, they are the size of a pack of cigarettes, approximately. However, Intel introduced a prototype chip with hemispheres, a fundamental characteristic to achieve the miniaturization of so-called catoms.
These are basically miniature pieces of matter so intricate that they can shape-shift into actual shapes of whatever you desire based on a quick, programmable system. Yes, that means you could potentially take that cell phone you have and program it to shape-shift into something smaller or larger based on your needs.
Sounds eerie that you can shape any piece of technology into any size or oblong shape you want, doesn't it? According to Intel, they're already working on the basics of the system, even though it's with larger objects and not the microscopic catoms that'll come later and be able to shape-shift any particular piece of technology we can imagine. That's right, the hype from the technology itself might get some developers at Intel so excited, it probably makes them give the illusion that catoms are right on the horizon.
If you've read the more esoteric nanotechnology treatises, you're undoubtedly familiar with the concept of "programmable matter" -- micro- or nano-scale devices which can combine to form an amazing assortment of physical objects, reassembling into something entirely different as needed. This vision of nanotechnology is light years away from today's world of carbon nanotubes or even the practical-but-amazing world of nanofactories. It shouldn't surprise you, however, to note that despite its fantastical elements serious research is already underway heading down the path to programmable matter called "CLAYTRONICS" at Carnegie-Mellon University, and "DYNAMIC PHYSICAL RENDERING" at Intel (which is supporting the CMU work), the synthetic reality project has already made some tentative advances, and the researchers are confident of eventual success. Just how long "eventual" may be is subject to debate.
According to the Claytronics project's Seth Goldstein and Todd Mowry, programmable matter is:
An ensemble of material that contains sufficient
  local computation
  actuation
  storage
  energy
  sensing & communication
which can be programmed to form interesting dynamic shapes and configurations. CLAYTRONICS is their way of bringing this concept into reality.
The claytronic cellphone in your pocket could morph into whatever tool you need. Videoconferencing would gain a physical dimension, with all the participants appearing in claytronic form, and surgeons could even work on claytronic enlargements of internal organs to perform robotic tele-surgery with extreme precision.