Micro electrostatic actuators in dual-stage disk drives with high track density

This paper presents a dual-stage actuator for high-density disk drive, using a voice coil motor (VCM) rotary actuator as a coarse actuator and a linear micro electrostatic actuator as a fine actuator. The micro electrostatic actuator proposed has trapezoidal static comb fingers and straight movable comb fingers. It has a linear static displacement voltage characteristic in a working range of 4 μm, sufficient for fine positioning of a read/write head. The actuator has a fast and stable dynamic response with a related setting of parameters. By adjusting micro leaf-spring constant and the mass of a micro HGA subsystem, the micro actuator system can achieve a 10 kHz bandwidth