Miami (AFP) - Inspired by cockroaches that can squeeze through tiny spaces, US scientists have designed a small robot that may one day help locate people in the rubble of earthquakes, tornadoes or explosions.

The technology by the University of California, Berkeley was unveiled Monday in the Proceedings of the National Academy of Sciences.

"What's impressive about these cockroaches is that they can run as fast through a quarter-inch (0.6 centimeter) gap as a half-inch (1.25 cm) gap, by reorienting their legs completely out to the side," said lead researcher Kaushik Jayaram, who is now a postdoctoral fellow at Harvard University.

"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."

The palm-sized robot, known as CRAM -- for compressible robot with articulated mechanisms -- is capped with a plastic shield, much like the wings on the back of a cockroach.

"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, a professor of integrative biology at UC Berkeley.

"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."

Researchers say their robots are inexpensive to make, and they are working on various versions for real-world testing.

Funding for the research has come from the US Army Research Laboratory, as part of a collaboration with between industry and university partners.