Self-fixing bridges, camouflaging cars closer to reality

Nature-inspired robotic materials can pave the way for development of prosthetics with a realistic sense of touch, bridges that detect damage and self-repair and vehicles with camouflaging capabilities, scientists say.
Advances in materials science, distributed algorithms and manufacturing processes are revolutionising robotic materials, according to a review by Nikolaus Correll, assistant professor of computer science, and research assistant Michael McEvoy, at the University of Colorado Boulder.
The robotic materials being developed by Correll Lab and others are often inspired by nature.
"We looked at organisms like the cuttlefish, which change their appearance depending on their environment, and the banyan tree, which grows above-ground roots to support the increasing weight of the trunk," Correll said.

"We asked what it would take to engineer such systems," Correll added.
While materials can already be programmed to change some of their properties in response to specific stimuli, robotic materials can sense stimuli and determine how to respond on their own.

Correll and McEvoy use the example of artificial skin equipped with microphones that would analyse the sounds of a texture rubbing the skin and route information back to the central computer only when important events occurred.
"The human sensory system automatically filters out things like the feeling of clothing rubbing on the skin," Correll said in the review published in the journal Science.

"An artificial skin with possibly thousands of sensors could do the same thing, and only report to a central 'brain' if it touches something new," Correll said.
While all of these materials are possible, the researchers cautioned that manufacturing techniques remain a challenge.
"Right now, we're able to make these things in the lab on a much larger scale, but we can't scale them down," Correll said.
The field also faces an education gap, the researchers said. Developing robotic materials requires interdisciplinary knowledge that currently is not provided by materials science, computer science or robotics curricula alone.
In the long run, Correll believes robotic materials will be used in everyday items, like shoe insoles that could sense pressure and adapt their stiffness to adjust to walking or running.