Acoustic driven microbubble motor device

We have developed an acoustic frequency driven microbubble motor (AFMO) device and achieved high-speed rotation up to 450 RPM and torque of 2.3 × 10-9 (N.m). Additionally, the bidirectional rotation of this device has been demonstrated by modulating input frequencies. This device, directly constructed from UV curable resin by a micro-3D printer, has four microscale cavities that contain micro air bubbles when immersed in water. Once external 4 kHz acoustic waves stimulate these four cavities, microbubbles are extracted and positioned at the entrances of the cavities. These four microbubbles have identical dimensions and oscillation resonant frequencies of 5.6 kHz based on theoretical calculations that can spin the AFMO device in a clockwise direction. Both the clockwise and the counterclockwise rotation of the AFMO device have observed at a 5.6 and 5.1 kHz frequency input, respectively.