Patent ID: 8027143

Claim:
A micro-electromechanical device comprising: a substrate, a movable element, a pair of electrodes arranged on the substrate and on the movable element to cooperate to move the movable element relative to the substrate, and a controller arranged to supply electrical power to the electrodes to move the movable element to an intermediate position between a maximum and a minimum position, the controller providing a pulse or pulses having a first level higher than a second level required to hold the movable element at the intermediate position and then reducing to the second level to stabilize the movable element at the intermediate position, wherein the controller is arranged to control a voltage differential between the electrodes to vary an electrostatic force, wherein the controller supplies a single pulse of a maximum supply level to control an increase in a gap between the electrodes, and wherein the controller supplies a sequence of pulses timed to dampen oscillations of the movable element to control a decrease in the gap between the electrodes.