Newly Designed Slider-Based Micro-Actuator for Magnetic Disk Drive

Abstract

A novel slider-based micro-actuator for magnetic disk drive was designed and fabricated to improve the magnetic head positioning accuracy. The micro-actuator consists of a head slider, an actuator base, flexible hinge elements, and a pair of unimorph actuators which has piezo-electric transducers and actuator arms as components. The slider body is able to rotate around the center of mass, and the movable end of the actuator arms are contacted but not fixed to the slider body, so the arms won't constrain the slider rotation and results to a large stroke. The actuator arms are actuated by piezo-electic transducers to apply a rotation torque to the slider. The stroke of 0.16µm peak-to-peak was obtained under a drive voltage of +/-20V and the frequency response of the slider tip excited by the piezo-electric actuators was fairly well, with slider sway mode frequency of 21.8kHz. The evaluation results showed the micro-actuator is able to improve the servo bandwidth, implemented in the disk drive in the future.

Keywords

• magnetic disk drive
• dual-stage servo
• micro-actuator
• head tracking
• piezo-electric actuator
• contact stiffness