Shape-Shifting Robot Exoskeleton Could Power Computers the Size of a Human Cell

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Graphene-glass bimorphs. Cornell University

Physicists have created a tiny, shape-shifting robotic exoskeleton they believe could power electronics the size of a human cell. The exoskeleton is sensitive to changes in the temperature or chemical makeup of its surrounding environment, and responds by changing its shape, making it something between a chameleon and a Transformer.

A team of researchers from the University of Cornell created the exoskeleton by modifying a "bimorph" motor—a composite of two substances, graphene and glass. When heat is applied, the bimorph can physically bend; graphene and glass don't respond to the same temperature the same way, so heat makes them expand at different rates, causing the shape to change.

Chemical reactions do the same. The bimorph will respond to chemical stimuli by pushing large ions into the highly reactive glass at its outer edge. Because the motor is so tiny, that outer edge actually comprises most of the glass, sort of like how a miniature pie has a much higher crust-to-filling ratio than a standard-sized one.

Graphene–glass bimorphs can be used to fabricate numerous micron-scale 3D structures, including (top to bottom) tetrahedron, helices of controllable pitch, high-angle folds and clasps, basic origami motifs with bidirectional folding and boxes. Cornell University

The researchers took a bending bimorph and upgraded it with flat, strategically placed panels that do not bend. This step allowed them to manipulate where any bending could or could not take place. From there, they can make the bimorph "fold" itself into any number of shapes. A paper describing the research was published in the Proceedings of the National Academy of Sciences.

The bimorphs they're producing are the thinnest ever created; one of them is the size of three red blood cells when folded, according to the press release. That's smaller than a neuron, or about one-fifth the width of a single human hair. The only comparable technology is a modern-day computer chip, according to International Business Times.

"Right now, you can make little computer chips that do a lot of information-processing…but they don't know how to move or cause something to bend," Paul McEuen, director of the Kavli Institute at Cornell for Nanoscale Science, said in a university press release.

Despite their tininess, the exoskeletons are still compatible with standard-scale semiconductors. The researchers have no current plans for practical applications, but believe that the work potentially opens a lot of doors for the nascent field of nanoscale robotics. They could be released inside a human body to study biological processes at the micron-scale, according to United Press International.

"You could put the computational power of the spaceship Voyager onto an object the size of a cell," Itai Cohen, a professor in Cornell's Department of Physics, said in the press release. "Then, where do you go explore?"