Patent ID: 9190937
Filing Date: 2015-11-17
Classification: B81B,B81C,H02N

Abstract:
1. A microelectromechanical systems (MEMS) device comprising: a substrate; a movable element positioned in spaced apart relationship above a surface of said substrate; at least one spring member interconnecting said movable element with said substrate, said at least one spring member enabling motion of said movable element, and said at least one spring member exhibiting a first stiffness; at least one electrode facing said movable element; at least one force feedback electrode facing said movable element; a voltage source in communication with said at least one electrode, said voltage source being configured to apply a spring softening voltage to said at least one electrode to shift a stiffness of said spring member from said first stiffness to a second stiffness, said second stiffness being less than said first stiffness; a sense circuit in electrical communication with said at least one electrode for generating an electrical output signal in response to an input stimulus imposed on said movable element; an electrostatic force feedback circuit interposed between said sense circuit and said at least one force feedback electrode for controlling a feedback voltage applied to said at least one force feedback electrode based on said electrical output signal; a detection circuit in electrical communication with said at least one electrode, said detection circuit being configured to detect a stiction condition of said movable element in response to an output signal from said at least one electrode; and a multiplexor circuit in communication with said at least one electrode, said at least one force feedback electrode, and said movable element, said multiplexor circuit being configured to set each of said at least one electrode, said at least one force feedback electrode, and said movable element to an equivalent voltage potential to effectively remove said spring softening voltage in response to said stiction condition.