Non-contact high-speed rotation of micro targets by vibration of single piezoelectric actuator

Micromanipulation provides researchers a new way to fabricate complex structures through assembling small components, and it is also a useful tool for single cell manipulation. Many micromanipulation methods have been proposed, but only the few are capable of rotation of the micro targets. In this paper, we present a simple non-contact high-speed rotation method based on the local flow generated by vibrating a single piezoelectric actuator in the fluids. A micro glass pipette is attached to the end of the piezoelectric actuator, and the other end is connected to a copper bar. When we input specific electric wave into the piezoelectric actuator, the tip of the micropipette will move circularly and generate a local swirl flow in the fluids. It can be applied to rotating micro targets with a high-speed. The mechanism of this method are analyzed, and simulation is utilized to analyze the vibration-induced local flow. Control strategies including the on-off control, coarse rotation speed control and fine rotation speed control are also designed. Experiments of rotating microbeads are carried out to prove the effectiveness, operability and efficiency of this method.