Patent ID: 8213127

Claim:
A microactuator comprising: a platform for fixing a head slider having magnetic recording and reproducing elements thereon; a substrate for holding and rotating the platform; a piezoelectric element held on the substrate and expanding or contracting in an in-plane direction of the substrate in response to an applied voltage to move the platform in the in-plane direction, located on the substrate and comprising a primary piezoelectric layer for generating an expansion force in the in-plane direction in response to the applied voltage and a secondary piezoelectric layer laminated on the primary piezoelectric layer opposite from the substrate surface for generating a contraction force in the in-plane direction in response to the applied voltage; and a first electrode and a second electrode laminated on the primary piezoelectric layer and the secondary piezoelectric layer, wherein a voltage is applied to the primary piezoelectric layer and the secondary piezoelectric layer between the first electrode and the second electrode; and the secondary piezoelectric layer has a polarization direction reversed from the polarization direction in the primary piezoelectric layer in response to the applied voltage, and the electric field for the applied voltage in the secondary piezoelectric layer is smaller than in the primary piezoelectric layer.