Surface-machined micromechanical membrane pump

An electrostatic micromechanical membrane pump for fluids and gases has been designed and fabricated with a process that is compatible with integrated circuits. The process consists of six photolithography steps and eight low-pressure chemical vapor depositions. No bulk silicon etchants or wafer bonding techniques are used. Each pump consists of an input valve, a pumping membrane, and an output valve. All parts are encapsulated by silicon nitride and are actuated by electrostatic forces. Actuation voltages of approximately 50 V are required for observable valve closure and membrane deflections. Typical gas pumping displacements are between 12 to 640 nL per cycle