Swiss Researchers Invent Sound-Powered Micro-Drones

Researchers at EPFL have developed micro-drones powered by sound. The vehicles use hollow resonant cavities that convert specific sound frequencies into thrust, generating motion in air and on water. By tuning the frequency emitted by a speaker, the team can selectively activate cavities to steer miniature boats and guide their micro “fliers.” Because the approach relies on cavities instead of motors, gears, or magnets, it could enable extremely small, lightweight robots and flexible sound-responsive designs.