Microrobots from China may be able to do without heavy batteries: scientists have taught them to generate electricity as they walk. This could help create miniature explorers to inspect narrow channels and industrial equipment, and to search for survivors under rubble.
A polymer membrane just 135 micrometers thick was applied to the robot’s legs. When it contacts suitable surfaces, such as aluminum, it triggers a chemical reaction that generates electricity. In tests, the robot took more than a million steps, using about two grams of aluminum.
However, the technology does not work everywhere: plastic, glass, soil and organic tissue are unsuitable for generating power. To cross such areas, the researchers added a small supercapacitor that stores energy. In the future, they plan to automate maintenance of the system so that the robots can operate independently for longer.
