Bidirectional pumping properties of a peristaltic piezoelectric micropump with simple design and chemical resistance

Abstract

A planar bidirectional valveless peristaltic micropump for controlling biosamples and reagent fluids was designed with a very simple structure and fabricated employing microelectromechanical system technologies, which include deep reactive ion etching in silicon and silicon–glass anodic bonding techniques. The proposed micropump consists of piezoelectric disks, silicon, and glass, thereby having the advantage of being resistant to aggressive media. The pump diaphragms are excited by applying pulse signal voltages to three lead zirconate titanate (PZT) disks on glass plates. For the channel and chamber in the silicon, the deep reactive ion etching process is utilized and a glass wafer is bonded to the pump-cavity side of the silicon wafer using an anodic bonding machine. The entire pump chip is 30×20×1 mm 3. The proposed micropump was able to control bidirectionally the flow rate of sample water at ∼12 μl/min (20 nl/stroke) and sample air at ∼60 μl/min (100 nl/stroke) based on a frequency of 10 Hz at 120 peak-to-peak voltage. In addition, actuation modeling of the PZT–glass actuator was performed using a Coventor simulator, CoventorWare, and the simulation results agreed well with the experimental measurements.