An improved valve-less pump fabricated using deep reactive ion etching

We present the first valve-less diffuser pump fabricated using the latest technology in deep reactive ion etching (DRIE). The pump is fabricated in a simple micromachining process in a double side polished silicon wafer anodically bonded to a glass wafer. Pump chambers and diffuser elements are etched in the silicon wafer using DRIE while inlet and outlet holes are etched using an anisotropic KOH-etch. The DRIE etch resulted in rectangular diffuser cross-sections. We present results on pumps with different diffuser dimensions in terms of diffuser neck width, length and angle. We reached a maximum pump pressure of 7.6 m H/sub 2/O (74 kPa) and maximum pump flow of 2.3 ml/min for water.