Acoustically propelled winged macroparticles

Self-propelled particles harvest and harness energy from their environment, transforming it into a controlled force that propels their motion. We present a mechanism to propel active macroparticles using low frequency noise (10–200 Hz). Thin polymer plates (wings) are acoustically excited at their second natural frequency; the mass of air displaced generates a counter-force, which propels the macroparticles. We show that the magnitude and direction of the propelling force can be tweaked through the wing’s shape, dimensions, and orientation. Finally, we design a macroparticle with bidirectional rotation: its rotation direction can be inverted by changing the frequency at which it is excited.