Forget batteries and electricity — the tiny robots of the future could run on moisture.
Researchers at Seoul National University in South Korea, have created robots that can “inchworm” forward by absorbing humidity from their surrounding environment. The so-called hygrobots, described this week in the journal Science Robotics, can crawl, wriggle back and forth, and twist like a snake. And in the future, they could be used for a variety of applications, including delivering drugs to human skin.
Mimicking the bristles of the Pelargonium carnosum seed, a shrubby plant from Africa, the hygrobot has two layers made out of nanofibers: one layer absorbs moisture and the other doesn’t. When the bot is placed on a wet surface, the humidity-sucking layer swells, shooting the bot up, away from the surface. Once the layer dries, the bot goes back down and the cycle repeats. That allows the bot to move.