MICROMACHINED FLAT-WALLED VALVELESS DIFFUSER PUMPS

The first valveless diffuser pump fabricated using the latest technolo gy in deep reactive ion etching (DRIE) is presented. The pump was fabr icated in a two-mask micromachining process in a silicon wafer polishe d on both sides, anodically bonded to a glass wafer. Pump chambers and diffuser elements were etched in the silicon wafer using DRIE, while inlet and outlet holes are etched using an anisotropic etch. The DRIE etch resulted in rectangular diffuser cross sections. Results are pres ented on pumps with different diffuser dimensions in terms of diffuser neck width, length, and angle. The maximum pump pressure is 7.6 m H2O (74 kPa), and the maximum pump flow is 2.3 ml/min for water. [219]