After running roaches through tunnels that were only as high as two pennies stacked flat, researchers at UC Berkeley have designed a cockroach robot that’s able to squeeze through tiny spaces at blazing speeds.
Such a roach bot, described in the Proceedings of the National Academy of Sciences, might eventually be deployed as search-and-rescue robobugs in rubble-strewn disaster zones and may cause scientists and engineers to redefine their ideas about the kinds of animals that can inspire “soft robotics.”
Study co-author Robert Full, a UC Berkeley biomechanist, has long explored how animals move – he’s analyzed how geckos stick to walls and built other roach-inspired running robots. But he soon became intrigued by the insects’ ability to wriggle their way into nooks and crannies – even though they technically have a hard, exoskeleton-clad body.
“Animals with exoskeletons like cockroaches can go everywhere, and infest any space, so we wondered, well, how did they do that?” Full said. “So we constructed a series of tight crevices to see what they could do.”
The researchers took American cockroaches (Periplaneta americana) – “the one you think you don’t have in your house, but you do,” Full said – and had them run through a tunnel 12 millimeters high. Then they reduced the tunnel height, down to 9 millimeters, and then 6 millimeters, and then to a tight 4 millimeters – less than a third of their standing body height. Until the last, tightest tunnel, the cockroach basically maintained its high speed, running with its legs spread out out as its body became increasingly smooshed.
“They run really fast even though they’re compressed in half, their legs completely splayed out to their side,” Full said. “They could still run at 20 body lengths per second, 60 centimeters a second — which if you scale it up is 70 miles an hour for a human.”