Effect of dual-stage actuator on positioning accuracy in 10 k rpm magnetic disk drives

We have developed a piezoelectric micro-actuator for dual-stage actuator systems in magnetic disk drives. This microactuator, which drives the head suspension assembly, is based on the shear deformation of piezoelectric elements. We installed the microactuator in one of Fujitsu's 3.5-inch commercial drives for evaluation of the servo system of dual-stage actuator. This paper describes the effect of the dual-stage servo system on positioning accuracy compared with the single actuator.