Self-priming and bubble tolerant micro-pump

Abstract

A self-priming and bubble tolerant planar micro-pump, which is fabricated by traditional technology, has been demonstrated and characterized. The micro-pump has a simple three-layered structure. Its two pump housings are made of polycarbonate and they are fabricated by computer numerical control (CNC) machine. The actuation membrane, which acts as the inlet and outlet valve membrane is cast in polydimethylsiloxane (PDMS). Using the PDMS membrane to act as the actuation membrane and valve membrane, we have solved the problem of sealing and poor compression ratio that most silicon based micro-pump faced. From the model of the membrane stroke volume, the flow rate of the pump is insensitive to the pump output pressure, and the output flow rate is linearly varying with actuating frequency. Flow rate up to 1000 μl/min of liquid has been achieved. More than 2m pump-head has been obtained when using water as the pumping medium. The robustness of the pump makes it suitable for disposable applications like biochip system.