Stochastic folding for chain programmable matter

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 57-59).The vision of programmable matter is to create a blob of material that can transform itself into an arbitrary form. One promising approach for achieving programmable matter is to construct a chain of identical nodes that can fold into arbitrary threedimensional shapes. Previous active electromechanical systems have demonstrated this concept but are currently costly, complex, and not robust enough to scale to smaller sizes or larger numbers of nodes. The goal of this thesis is to explore methods of simplifying chain programmable matter by removing the actuator from each node and, instead, putting energy into the system externally through stochastic vibrations. Each node takes this random energy input and rectifies it to produce motion towards the target position. We propose two variants of this system: 1) smart clutches that can be reprogrammed in situ and fold through arbitrary paths in configuration space and 2) ratchets that are programmed ahead of time and are entirely passive. We developed a chain using the ratchet concept and also constructed a new active, electromechanical chain with reduced cost and improved speed and torque compared to previous electromechanical systems. Through experimental and computer simulated studies, we determined that stochastic actuation can simplify and reduce the cost of these systems. We have also identified how the size of the increments of the ratchet, length of the chain, and the amplitude and frequency of agitation affect the folding time and success rate. In addition, we show that passive folding systems should improve in performance as the hardware scales down.by Maxim B. Lobovsky.S.M

The Milli-Motein: A self-folding chain of programmable matter with a one centimeter module pitch

The Milli-Motein (Millimeter-Scale Motorized Protein) is ca chain of programmable matter with a 1 cm pitch. It can fold itself into digitized approximations of arbitrary three-dimensional shapes. The small size of the Milli-Motein segments is enabled by the use of our new electropermanent wobble stepper motors, described in this paper, and by a highly integrated electronic and mechanical design. The chain is an interlocked series of connected motor rotors and stators, wrapped with a continuous flex circuit to provide communications, control, and power transmission capabilities. The Milli-Motein uses off-the-shelf electronic components and fasteners, and custom parts fabricated by conventional and electric discharge machining, assembled with screws, glue, and solder using tweezers under a microscope. We perform shape reconfiguration experiments using a four-segment Milli-Motein. It can switch from a straight line to a prescribed shape in 5 seconds, consuming 2.6 W power during reconfiguration. It can hold its shape indefinitely without power. During reconfiguration, a segment can lift the weight of one but not two segments as a horizontal cantilever.United States. Defense Advanced Research Projects Agency. Programmable Matter ProgramUnited States. Defense Advanced Research Projects Agency. Maximum Mobility and Manipulation (M3) ProgramUnited States. Army Research Office (Grant W911NF-08-1-0254)United States. Army Research Office (Grant W911NF-11-1-0096)Massachusetts Institute of Technology. Center for Bits and Atom

Design and analysis of a robust, low-cost, highly articulated manipulator enabled by jamming of granular media

Hyper-redundant manipulators can be fragile, expensive, and limited in their flexibility due to the distributed and bulky actuators that are typically used to achieve the precision and degrees of freedom (DOFs) required. Here, a manipulator is proposed that is robust, high-force, low-cost, and highly articulated without employing traditional actuators mounted at the manipulator joints. Rather, local tunable stiffness is coupled with off-board spooler motors and tension cables to achieve complex manipulator configurations. Tunable stiffness is achieved by reversible jamming of granular media, which-by applying a vacuum to enclosed grains-causes the grains to transition between solid-like states and liquid-like ones. Experimental studies were conducted to identify grains with high strength-to-weight performance. A prototype of the manipulator is presented with performance analysis, with emphasis on speed, strength, and articulation. This novel design for a manipulator-and use of jamming for robotic applications in general-could greatly benefit applications such as human-safe robotics and systems in which robots need to exhibit high flexibility to conform to their environments.United States. Defense Advanced Research Projects Agency (Maximum Mobility and Manipulation Program