The crawling machine self-assembled over 270 s. The self-assembling process occurs in five steps: outer leg folding, motor alignment, body folding, standing up, and inner leg folding. After self-assembly, it walks without any further intervention (Video 1 of 10.1126/science.1252610). - Robot folds itself—and walks away news.sciencemag.org/technology/2014/08/video-robot-folds-itself-and-walks-away Turn your back on this seemingly flat piece of hardware, and it just might fold itself into a crab and scuttle away. Using origami-inspired computing, researchers have built a crawling robot that assembles itself in 4 minutes, as shown in the above video. The team made a five-layer composite out of paper, a flexible circuit board, and shape-memory polymers that contract when heated to 100°C. Heat generated locally by the embedded circuits triggers hinges in the composite to fold, while mechanical features in the composite determine how far and in what direction each hinge bends. The precise folding pattern is generated by origami design software and programmed into the robot’s microcontroller. Once the machine is assembled, a motor interacts with linkage structures in its legs to drive it crawling and turning without human intervention. The researchers hope this early prototype will eventually lead to cheap, quick, and customized robot manufacture. One possibility: mass deploying the flat robots into collapsed buildings to navigate small spaces in search-and-rescue missions. - Video: Robot folds itself—and walks away video.sciencemag.org/News/3719196096001/1 Turn your back on this seemingly flat piece of hardware, and it just might fold itself into a crab and scuttle away. References 1. A method for building self-folding machines Science 8 August 2014: Vol. 345 no. 6197 pp. 644-646 DOI: 10.1126/science.1252610 sciencemag.org/content/345/6197/644 Editors Summary Folding robots and metamaterials The same principles used to make origami art can make self-assembling robots and tunable metamaterials—artificial materials engineered to have properties that may not be found in nature (see the Perspective by You). Felton et al. made complex self-folding robots from flat templates. Such robots could potentially be sent through a collapsed building or tunnels and then assemble themselves autonomously into their final functional form. Silverberg et al. created a mechanical metamaterial that was folded into a tessellated pattern of unit cells. These cells reversibly switched between soft and stiff states, causing large, controllable changes to the way the material responded to being squashed. Science, this issue p. 644 (1), p. 647 (2); see also p. 623 (3) Abstract Origami can turn a sheet of paper into complex three-dimensional shapes, and similar folding techniques can produce structures and mechanisms. To demonstrate the application of these techniques to the fabrication of machines, we developed a crawling robot that folds itself. The robot starts as a flat sheet with embedded electronics, and transforms autonomously into a functional machine. To accomplish this, we developed shape-memory composites that fold themselves along embedded hinges. We used these composites to recreate fundamental folded patterns, derived from computational origami, that can be extrapolated to a wide range of geometries and mechanisms. This origami-inspired robot can fold itself in 4 minutes and walk away without human intervention, demonstrating the potential both for complex self-folding machines and autonomous, self-controlled assembly. Supplementary Materials sciencemag.org/content/suppl/2014/08/06/345.6197.644.DC1/Felton.SM.pdf Video Movie S1: The crawling machine self-assembled over 270 s. The self-assembling process occurs in five steps: outer leg folding, motor alignment, body folding, standing up, and inner leg folding. After self-assembly, it walks without any further intervention. sciencemag.org/content/suppl/2014/08/06/345.6197.644.DC1/1252610s1.mpg Movie S2 The assembly process uses planar fabrication methods to make assembly fast and easy. Fabrication requires a solid ink printer, a ferric chloride etch tank, a laser machining system, and a board and pins for aligning the layers. sciencemag.org/content/suppl/2014/08/06/345.6197.644.DC1/1252610s2.mpg 2. Using origami design principles to fold reprogrammable mechanical metamaterials Science 8 August 2014: Vol. 345 no. 6197 pp. 647-650 DOI: 10.1126/science.1252876 sciencemag.org/lookup/doi/10.1126/science.1252876 Abstract Although broadly admired for its aesthetic qualities, the art of origami is now being recognized also as a framework for mechanical metamaterial design. Working with the Miura-ori tessellation, we find that each unit cell of this crease pattern is mechanically bistable, and by switching between states, the compressive modulus of the overall structure can be rationally and reversibly tuned. By virtue of their interactions, these mechanically stable lattice defects also lead to emergent crystallographic structures such as vacancies, dislocations, and grain boundaries. Each of these structures comes from an arrangement of reversible folds, highlighting a connection between mechanical metamaterials and programmable matter. Given origami’s scale-free geometric character, this framework for metamaterial design can be directly transferred to milli-, micro-, and nanometer-size systems. Supplementary Materials sciencemag.org/content/suppl/2014/08/06/345.6197.647.DC1/Silverberg.SM.pdf Movie S1: Introduction of a 4 × 4 Miura-ori demonstrating its structure and com- pressive behavior. sciencemag.org/content/suppl/2014/08/06/345.6197.647.DC1/1252876s1.mp4 Movie S2: Compression of a 4 × 4 Miura-ori with a PTD showing its formation, mechanical response, and restoration to a normal lattice. sciencemag.org/content/suppl/2014/08/06/345.6197.647.DC1/1252876s2.mp4 Movie S3: Compression of a 4 × 4 Miura-ori with a 1-2 defect pair showing its formation, mechanical response, and restoration to a normal lattice. sciencemag.org/content/suppl/2014/08/06/345.6197.647.DC1/1252876s3.mp4 Movie S4: Compression of a 4 × 4 Miura-ori with a 2-4 defect pair showing the formation, mechanical response, and restoration to a normal lattice. sciencemag.org/content/suppl/2014/08/06/345.6197.647.DC1/1252876s4 3. Folding structures out of flat materials Science 8 August 2014: Vol. 345 no. 6197 pp. 623-624 DOI: 10.1126/science.1257841 sciencemag.org/lookup/doi/10.1126/science.1257841 Origami is the art of intricately folding a sheet of paper into elaborate three-dimensional (3D) sculptures and objects. In this issue, two reports focus on different aspects of the thriving field of origami engineering. On page 644, Felton et al. (1) report on origami morphing structures, and on page 647, Silverberg et al. (2) report on origami-based metamaterials.
Posted on: Sun, 10 Aug 2014 23:22:08 +0000