Non-Contact Rotation by Acoustic Streaming Generated by a Cylinder with Multiple Small Through-Holes

This research aims to apply acoustic jet generation and acoustic levitation to realize a non-contact actuator that levitates and rotates the cylinder. The cylinder with holes between the vibration source and the base is levitated. If a side hole is added, a jet is also generated from the side hole, and the cylinder rotates due to the reaction force. Finite element analysis was used to design the hole so that the sound pressure in the center of the hole would be greater. For a 28 kHz vibration source, the cylinder was designed with a diameter of 10 mm, a thickness of 5 mm, a through hole of 1 mm in diameter in the central axis, and a side hole A perpendicular to the through hole from the side of the cylinder. In addition, a side hole B perpendicular to side hole A was provided from the side of the cylinder to rotate the cylinder with acoustic jets. It is indicated that acoustic jets are generated in both holes. In the experiment, it was confirmed that a cylinder with holes was rotated by the acoustic jets. The direction of rotation depended on the direction of side hole B.