We may fear cockroaches for their ability to quickly squeeze through the tiniest cracks, but researchers from the University of California, Berkeley think that this is justified. With the ability to squish themselves into cracks just one-tenth-of-an-inch wide, they can still maintain the ability to run at high speeds even in this condensed state.

Using their knowledge of American cockroaches (Periplaneta americana), the team of researchers created a robot that possesses these same abilities, which could aid in the search-and-rescue operations that take place in the rubble of tornadoes, earthquakes and explosions.

"What's impressive about these cockroaches is that they can run as fast through a quarter-inch gap as a half-inch gap, by reorienting their legs completely out to the side," said Kaushik Jayaram, who led the study. "They're about half an inch tall when they run freely, but can squish their bodies to one-tenth of an inch - the height of two stacked pennies."

Jayaram and his team designed a simple, cheap and effective robot the size of the palm of a human hand that possesses the ability to splay its legs outwards even when squashed, as well as a plastic shield capped on top, mimicking the tough, smoother wings that cover the backs of cockroaches.

The miniature robot, which they named Compressible Robot with Articulated Mechanisms (CRAM), was able to squeeze its way into cracks and crevices half its height and still retain its ability to run.

"In the event of an earthquake, first responders need to know if an area of rubble is stable and safe, but the challenge is, most robots can't get into rubble," said Robert Full, who oversaw the research. "But if there are lots of cracks and vents and conduits, you can imagine just throwing a swarm of these robots in to locate survivors and safe entry points for first responders."

"This is only a prototype, but it shows the feasibility of a new direction using what we think are the most effective models for soft robots, that is, animals with exoskeletons," he added. "Insects are the most successful animals on earth. Because they intrude nearly everywhere, we should look to them for inspiration as to how to make a robot that can do the same."

The findings were published in the Feb. 23 issue of the Proceedings of the National Academy of Sciences.