Cockroaches, known for their superior survival skills, are the inspiration behind the hardy, insect-like robot from the lab of Liwei Lin, professor of mechanical engineering. The robot, which weighs less than one-tenth of a gram, can withstand a weight of around 60 kg — about the weight of an average human — which is approximately 1 million times the weight of the robot. The size of a large postage stamp, the robot is made of a thin sheet of polyvinylidene fluoride, a piezoelectric material that expands or contracts with electricity. The sheet is covered with a layer of an elastic polymer, initially bent at an angle. The researchers added a front leg so that, as the material bends and straightens under an electric field, the oscillations propel the device forward in a leapfrogging motion. The resulting robot can move at a speed of 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 also zip through tubes, climb small slopes and carry light loads, such as a peanut. Such tiny, resilient robots could play a role in search and rescue missions, squeezing into spots too small or dangerous for a dog or human to go.