A piezoelectric pump with composite vibrator for bubble resistance

Piezoelectric pumps, as microfluidic drive units, are widely used in microfluidic systems. Due to the fact that most piezoelectric pumps are driven by displacement, the introduction of air bubbles will produce a significant impact on their output performance. To minimize the adverse effect of air bubbles, a piezoelectric pump with composite vibrator (PPCV) is proposed. The composite vibrator consists of the active vibrator and the passive vibrator. By vibrating the passive vibrator in the pump chamber, it prevents bubbles retention. Multi-physics field simulation is established，which verifies the PPCV is feasible. Furthermore, a prototype is fabricated and experimentally investigated. At a voltage of 300 Vpp, the experimental results indicate a maximum output flow rate of 41.4 ml/min and a maximum output pressure of 18.7 kPa. After continuously entering 100 bubbles, the output performance of the PPCV decreases by less than 10 %, indicating that the PPCV owns excellent bubble resistance ability. The PPCV provides a new approach to microfluidic pumping devices.