Combined servo-tracking and preload-controlling microactuator

摘要

A dual-acting disc drive micro-actuator is formed of a stack of adjoining layers. The stack includes first through fifth layers. The first layer includes first and second spaced apart top electrodes. The second layer includes a first piezoelectric element electrically coupled to the first and second top electrodes. The third layer includes a center electrode electrically coupled to the first piezoelectric element. The fourth layer includes a second piezoelectric element electrically coupled to the center electrode. The fifth layer includes a first bottom electrode electrically coupled to the second piezoelectric element. The first and second piezoelectric elements are expandable and contractible in a common length direction in response to respective electrical fields applied between the center electrode and the first top electrode, the second top electrode and the first bottom electrode.