Electrostatic actuator, variable capacitance device and a method of driving the electrostatic actuator

摘要

In a simple configuration, to provide an electrostatic actuator, such as it is possible to obtain a strong separation force when separating the first movable beam from the fixed electrode electrostatic actuator 4 includes a stationary driving electrode 21 provided on the silicon substrate 2, a first movable beam 31 and the second movable which is telescopically constructed succession bellows-like forms mutually folded structure has a beam 32, by the electrostatic force between the first movable beam 31 and the fixed drive electrode 21, together with both the movable beam is the first movable beam 31 extends in a bellows-like approaches to the fixed driving electrode 21, the two movable trabecular the electrostatic force, the first movable beam 31 and a movable portion 22 away from the fixed driving electrode 21 shrinks both movable beam is in a bellows, at least one of the two movable beam, an insulator portion which forms a principal, insulating the surface of the stationary driving electrode 21 side of the body portion and from this and a conductive layer formed on at least one surface of the opposite side