Drone-maker AeroVironment Inc unveiled a small four-rotor surveillance helicopter on Tuesday that can be carried in a small pouch and launched from the palm of a hand.
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.