Integrable active microvalve with surface micromachined curled-up actuator

An integrable electrostatic microvalve consisting of a curled-up cantilever movable part and a square valve orifice comprising of three pyramidal channels in tandem is presented. The curled-up cantilever, which consists of a silicon dioxide beam with a very thin layer of Cr, is formed by surface micromachining. The valve orifice is fabricated by bulk micromachining in such a way as to merge with the surface micromachining process. This process provided better control of the orifice dimensions. Measured switching voltage of 30 volts has been obtained. Linear flow versus differential pressure characteristics have been obtained from this type of triple tandem pyramidal orifice.