Electrostatic piggyback microactuators for head element positioning

We propose a new type of 3/sup rd/ generation MEMS piggyback actuator mechanism, which is suitable for integration with a read/write head device. An SOI wafer is patterned into a multiple-plate electrostatic actuator (2 /spl mu/m gap) by a deep RIE process. Prototype actuators (2 mm /spl times/ 3 mm /spl times/ 0.6 mm) without a head device have been developed to test the electromechanical characteristics. Typical mechanical stroke of 0.5 microns with a voltage of DC 60 V and resonant frequency of 16 kHz have been obtained. An analytical model has predicted that a 0.15 micron displacement would be possible for 200 Gbit/in/sup 2/ model when the electrostatic gap is designed to be 0.5 micron.