Electrostatic actuators with intrinsic stress gradient

摘要

An electrostatic actuator with an intrinsic stress gradient is provided. The electrostatic actuator comprises an electrode and an electrostatically actuated beam fixed at one end relative to the electrode. The electrostatically actuated beam further includes a metal layer made substantially of a single metal with an induced stress gradient therein. The stress gradient in the metal layer determines the initial curvature of the beam. Upon electrostatic actuation of the beam, the beam is deflected from its initial curvature relative to the electrode. In one embodiment, the electrostatically actuated beam is used as a top movable electrode of an electrostatically actuated variable capacitor. The capacitance of the electrostatically actuated capacitor is changed upon electrostatic actuation of the beam.