DJI, a premier drone-maker, is facing reports that its most consumer-friendly aircraft is randomly plunging from the sky, a cause for concern over safety issues.
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.