Distributed MEMS electrostatic pumping devices
A MEMS pumping device driven by electrostatic forces comprises a substrate having at least one substrate electrode disposed thereon. Affixed to the substrate is a moveable membrane that generally overlies the at least one substrate electrode. The moveable membrane comprises at least one electrode element and a biasing element. The moveable membrane includes a fixed portion attached to the substrate and a distal portion extending from the fixed portion and being moveable with respect to the substrate electrode. A dielectric element is disposed between the at least one substrate electrode and the at least one electrode element of the moveable membrane to provide for electrical isolation. In operation, a voltage differential is established between the at least one substrate electrode and the at least one electrode element which displaces the moveable membrane relative to the substrate to thereby controllably distribute matter residing between the substrate and the distal portion of the moveable membrane. In a further embodiment the MEMS pumping devices comprise more that two moveable membranes that are configured so as to maximize flow in a desired direction. Additional embodiments include more than one electrode element disposed within the moveable membrane that are capable of individual and sequential biasing to improve overall net flow in the desired flow direction.