A town called Deer Trail, located an hour east of Denver, Colo., is considering issuing a novel kind of hunting permit. If passed, the town would give residents licenses to “kill” drones … by shooting them out of the air.
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.