Self-sculpting sand assembles itself into shapes

Researchers have come up with algorithms that could someday get sand to form itself into any shape you want it to take.

Sandboxes will never be the same again.

Picture this: You place a tiny model of a footstool inside a box filled with sand. A few seconds later, you reach into the box again and pull out a life-sized footstool: The sand has assembled itself into this shape.

Someday, this vision will be the culmination of work by Daniela Rus, a professor of computer science and engineering at MIT, and her student Kyle Gilpin at MIT's Distributed Robotics Laboratory (DRL). In May, at the IEEE International Conference on Robotics and Automation — the world’s premier robotics conference — Rus and Gilpin will present a paper outlining the algorithms that will make such "smart sand" possible. They've already tested their algorithms using 10-millimeter cubes that contain microprocessors and magnets on four sides.

Someday, such self-sculpting sand could help you when, say, you're driving along and your tire rod has broken. You could get the sand to form the new shape you need.

How it works

The best way to describe how smart sand works is to think of the way a sculptor carves. Instead of each grain of sand having to figure out its place and the shape having to assemble itself grain by grain, the heap of sand is like one big block of marble. The grains communicate with each other and form the bonds necessary to create the three-dimensional object, and then all the unneeded grains just fall away.

When the object is no longer needed, the grains detach from each other to become a heap of sand again.

Test with smart pebbles

Gilpin and Rus have already used their algorithms on the 10-millimeter-cubed "smart pebbles" (pictured above) to create a two-dimensional object. Four faces of the cubes each contain magnets that can be turned on or off with a single electric pulse.

The magnets enable the pebbles to connect as well as to communicate and share power. Each pebble also has a microprocessor containing some working memory -- 2 kilobytes -- and some program code -- 32 kilobytes worth.

While true smart sand would require the grains to be much smaller than the smart pebbles, those are now possible with the algorithms Rus and Gilpin have developed, according to Robert Wood, an associate professor of electrical engineering at Harvard University. “Take the core functionalities of their pebbles,” Wood, who directs Harvard’s Microrobotics Laboratory, told MIT News Office. “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.”

To see more about how the sand self-sculpts, watch this video:

via: MIT News Office

photo: Top: The "smart pebbles" — 10-millimeter cubes with processors and magnets built in. (M. Scott Brauer/MIT News Office) Bottom: The smart cubes each contain magnets (shown in red) whose magnetism can be switched on and off. (M. Scott Brauer/MIT News Office)

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