In Development: Tiny, “Self-Sculpting,” Sand-Like Robots

By April 3, 2012

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In an experimental robotics project that sounds like a cross between a villain from the Terminator franchise and a nemesis from the Spiderman comics, researchers at the Massachusetts Institute of Technology are working on a network of tiny, sand-like robots that can assemble themselves into complex shapes.

As researchers at MIT’s Distributed Robotics Laboratory envision the project, you would be able to drop a miniature model of an object into a box of cube-shaped robot sand grains, and they would rapidly lock together like Lego bricks in order to assemble themselves into a large-scale replica.

At present, they’ve prototyped the technology with “smart pebbles,” about 10 millimeters to an edge, on which four faces can be magnetized or demagnetized with a single pulse and can stay magnetized without a constant current, unlike traditional electromagnets.

The intelligence of each pebble is starkly limited, with each unit’s microprocessor able to store store just 32 kilobytes of code 2 kilobytes of working memory. In fact, researchers say that a principal challenge in realizing the technology will be developing a way for the grains to communicate with one another without each storing an entire 3-D map of the object to be recreated.

“How do you develop efficient algorithms that do not waste any information at the level of communication and at the level of storage?” asked co-author Daniela Rus, adding that the grains should be able to function even if they start in a jumbled-up configuration. “We’d like to not have to know ahead of time what our block looks like.”

Technical limitations have kept the researchers from adding magnets to the remaining two sides of each cube, but they have used simulations to establish that their algorithm would work with grains that were magnetic on all six sides.

The trick now, researchers say, is to build the pebbles smaller.

“Take the core functionalities of their pebbles,” Harvard Microrobotics Laboratory director Robert Wood. “They have the ability to latch onto their neighbors; they have the ability to talk to their neighbors; they have the ability to do some computation. Those are all things that are certainly feasible to think about doing in smaller packages.”

The technology calls to mind a number of antagonists from fantasy and science fiction, including the Spiderman villain Sandman, who was made out of sand-like particles and could reshape or disintegrate himself when convenient.

Image: MIT