Created by researchers at the University of California, Berkeley, the durable robot can also withstand a load of around 60kg, which is approximately one million times its own weight. The study is described Science Robotics.
"Most of the robots at this particular small scale are very fragile. If you step on them, you pretty much destroy the robot," said Liwei Lin, a professor of mechanical engineering at UC Berkeley and senior author of a new study that describes the robot. "We found that if we put weight on our robot, it still more or less functions."
According to UC Berkeley, small, durable robots like these could assist search and rescue missions by getting into places where dogs or humans can't fit, or where it may be too dangerous for them to go.
"For example, if an earthquake happens, it's very hard for the big machines, or the big dogs, to find life underneath debris, so that's why we need a small-sized robot that is agile and robust," said Yichuan Wu, first author of the paper, who completed the work as a graduate student in mechanical engineering at UC Berkeley.
The cockroach-inspired robot is made of a thin sheet of a piezoelectric material called polyvinylidene fluoride (PVDF) which is coated in a layer of an elastic polymer, which causes the sheet to bend. The team then added a front leg so that, as the material bends and straightens under an electric field, the oscillations propel the device forward.
UC Berkeley further claim that the resulting robot can move along the ground at 20 body lengths per second, a rate comparable to that of a cockroach and reported to be the fastest pace among insect-scale robots. It can move through tubes, climb small slopes and carry small loads.
"People may have experienced that, if you step on the cockroach, you may have to grind it up a little bit, otherwise the cockroach may still survive and run away," Lin said. "Somebody stepping on our robot is applying an extraordinarily large weight, but [the robot] still works, it still functions. So, in that particular sense, it's very similar to a cockroach."
The cockroach-inspired robot is currently tethered to a thin wire that carries an electric voltage that drives the oscillations. The team is experimenting with adding a battery so the robot can move independently. They are also looking to add gas sensors and are improving the design of the robot so it can be steered around obstacles.