Acoustic Vibration-Induced Actuation of Multiple Microrotors in Microfluidics

Simultaneous and uniform actuation of multiple microrotors with easy fabrication method has been gathering significant attention in the field of precise microfluidic manipulation. In this work, the use of a piezoelectric vibration stage is presented to achieve the tunable acoustic vibration-induced actuation of multiple microrotors fabricated by two-photon polymerization. A series of curved sharp tips are predefined on the microrotors, which can generate paired asymmetric acoustic microstreaming to propel the rotor rotating around the stator with <1 kHz acoustic vibration. Microrotor's rotational speed can be readily controlled by tuning the signal input frequency and the number of rotor arms. A rotational speed of approximate to 1600 RPM can be achieved by a series of microrotors in aqueous solutions. This method enables easy and versatile microrotor fabrication and remote actuation of multiple rotors with simplicity and uniformity, providing promising solutions in various microfluidic manipulation applications.