This summer, one small robot will have a big adventure. Last year, hitchBOT, the Canadian hitchhiking robot, traveled across Canada with a lot of help from benevolent fellow travelers.
Robots clean rivers and sort waste, monitor ecosystems, and inspect renewable-energy infrastructure. But even the greenest robot has an environmental footprint.
EPFL engineers have designed acoustic cavities that convert sound waves into thrust, propelling small robots and ultralight aerial vehicles without on-board actuators or electronics.