Rotary piezoelectric actuator for dual stage actuation system in high-density hard disk drive

This paper presents a novel piezoelectric-based multilayer rotary micro-actuator for a dual stage actuation system used in high-track density hard disk drives. The actuator, as the secondary fine actuator, could be mounted on flexure tongue and control the motion of the slider to perform high-frequency track following. The configuration, operation, and fabrication of the actuator are described. The controllable stroke of the actuator and the resonance frequency of the slider/actuator assembly have been evaluated. A corresponding 14.5 mm HGA integrated with the actuator has been designed and dynamics of the HGA have been simulated. The results reveal that the proposed rotary actuator is capable of meeting the prescribed stroke and frequency specifications and should be a promising approach to implement the dual-stage servo in hard disk drives.