Researchers at University of California at Berkeley are developing a mechanical roach after finding its exoskeleton is uniquely suited to fitting into small spaces

Search and rescue missions of the future could be led by a horde of robot cockroaches, with US researchers developing a mechanical version of the reviled insect in order to serve the whims of its human overlords.

A University of California at Berkeley team found that cockroaches, despite their reputation as unwanted vermin, are superbly adaptable creatures able to contort their bodies to fit into various small and awkward spaces.

By constructing a special obstacle course, the researchers found that an American cockroach could slip through a space smaller than a quarter of its standing body height in less than a second and withstand forces of around 900 times its own weight without sustaining injury. A cockroach is able to compress its exoskeleton to around half its original size in order to achieve these feats.

The cockroach could also move at 20 body lengths a second and also use a little understood form of locomotion called “body-friction-legged crawling” when moving in confined spaces.

Inspired by the cockroach, Kaushik Jayaram and Robert Full have constructed a robot that can also compress itself by more than half to fit through narrow spaces, aided by a low-friction shell.

The robot, dubbed Cram, is about the size of a person’s palm and is being earmarked for a range of uses, such as finding people buried under rubble after earthquakes or other disasters. Its development has been published in the Proceedings of the National Academy of Sciences.

“We need low-cost robots as first responders and we feel this is really the best model,” Full said. “It has an origami-like exoskeleton, it can go into tiny spaces and keep moving. A swarm of these cockroach robots could locate people buried under debris.

“Animals that are soft, such as worms and slugs, are masters of shape-changing whereas arthropods, such as spiders and insects, take advantage of their rigid exoskeletons to run and jump. But cockroaches can go anywhere, they can slip through cracks and crevices.”

Full said the cockroach robot will be outfitted with sensors before it is deployed into the field. There is commercial interest in the idea, although no company has yet taken it up.

The robot, which has a shell made from a laser-cut cardboard-like substance, is a further advance in an area of robotics that has already dragooned cockroaches for human use. Engineers in Texas have infused live cockroaches with computers wired into the animal’s nervous system. A human operator is able to control the direction of the cockroach’s scuttle with a push of a button.

The cockroach is part of an emerging genre of inventions called “soft” robots. In contrast to traditional rigid-limbed robots, researchers are developing robots that can stretch, contort and squeeze into small spaces. Soft robots modeled on animals include a caterpillar, a jellyfish and a “fish-bot”.

“It’s about doing something beyond just running with two legs on the ground,” Full said, “The big picture is wonderful, this is just the beginning. You can use these robots for structural inspections, search and rescue, security, environmental monitoring, you name it. The next generation of robots is very exciting because we can build a prototype in a day rather than months or years and start testing it.”