The American cockroach is elusive. Very quickly she crawls into all sorts of cracks and crevices that she shouldn’t actually fit into. She just squeezes together if need be: she can withstand a pressure of 900 times her body weight undamaged and reaches top speeds of 50 body lengths per second – which corresponds to about 1.5 meters.
A Chinese-American research team has now presented a robot that can compete with the biological model in terms of size, speed and, in particular, robustness. “If you just step on a cockroach without turning your foot, there is a good chance that it will survive and flee,” sagt Liwei Lin (University of California at Berkeley). “If someone steps on our robot, it still works. In that respect it is very similar to a cockroach.”
Postage stamp at a gallop
This exhausts the similarities: The miniature robot has more of the shape of a postage stamp. It is constructed from the piezoelectric material polyvinylidene fluoride (PVDF) and bends or stretches its flat body depending on the applied electrical voltage, which allows it to move forward like a gallop. The speeds that can be achieved depend heavily on the geometry, the researchers report in the current issue of Science Robotics. With a 10 millimeter long robot they reached the highest speed with 20 body lengths per second. To do this, the applied voltage had to oscillate at 850 Hz, close to the robot’s resonance frequency.
The robot is currently still attached to the cable. However, the researchers were able to show that it can transport six times its body weight and climb inclines of more than 15 degrees. You are therefore confident that you will be able to equip it with its own energy supply and sensors in the future. One day he could search for survivors in the rubble of collapsed buildings or warn rescue workers about leaking gas pipes.