John Markoff John Markoff is a New York Times science reporter and author of the new book, Machines of Loving Grace: The Quest for Common Ground Between Hu
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.