Acoustic Propeller Based on Air Jets from Acoustic Streaming

This paper describes acoustic thruster and lifter capable of generating propulsion force on-demand from synthetic air jets generated by acoustic waves passing through orifices on a thin plastic (shaped with laser-machining) covering a sound source (audio speaker). The orifice array pattern was optimized through experiments to produce large thrust force. By varying driving condition and operating frequency, the transducer that weighs 603 mg can rotate, or jump 2.8 mm high and 100 mm far, propelled by the air jets. When tested as an acoustic lifter, the transducer is capable of lifting a plastic piece of 299 mg and rotating a metal piece of 20.4 g. The device could also be driven with acoustic signal instead of electrical power.