Self-Sculpting Sand

New algorithms could enable heaps of 'smart sand' that can assume any shape, allowing spontaneous formation of new tools or duplication of broken mechanical parts. These algorithms were created by researchers at the Distributed Robotics Laboratory (DRL) at MIT's Computer Science and Artificial Intelligence Laboratory. They also tested the algorithms on somewhat larger particles - cubes about 10 millimeters to an edge. To attach to each other, to communicate, and to share power, the cubes use 'electropermanent magnets' - materials whose magnetism can be switched on and off with jolts of electricity. Each cube has magnets, recognizable by the reddish wires wrapped around them, on four of its six faces.

Transcript

00:00:01 This video shows how we can use our Robot Pebbles system to duplicate complex 2D shapes. We start by surrounding the original shape, (the humanoid form shown in black), with Robot Pebble modules. As the Robot Pebbles communicate, their connecting bonds flash orange. The basic idea is to identify and duplicate the modules on the border of the original shape. The modules turn blue when they realize they may border on the shape to be duplicated. Using a geometric algorithm, the system differentiates between the blue modules that

00:00:32 border on the shape to be duplicated, and the blue modules on the exterior on the composite block of material. As each blue module determines that it borders on the shape to be duplicated, it turns yellow, and sends a message to its conjugate border module, that lies some distance to the right. This offset distance is automatically chosen by the system in such a way to ensure that the original and duplicate shapes never overlap. Once the conjugate border mirrors the border of the original shape, the system performs a flood fill process

00:01:01 to inform all modules inside the new duplicate border that they are part of the duplicate shape. As a result, they turn orange. Finally, once all the modules that form the duplicate shape have been notified of their unique status, the system breaks all the unnecessary mechanical bonds, between the other modules, leaving only the original and the duplicate shapes behind. We have extended this process to three dimensional shapes, and we have run hundreds of experiments to demonstrate that it runs reliably and robustly with any original shape.