Design, fabrication and dynamic analysis of a PZT-actuated silicon suspension

A silicon suspension, suitable for use in a piezoelectrically actuated dual-stage servo system for magnetic Hard Disk Drives (HDDs), has been designed, fabricated and partially tested on the rotating disk. The suspension has an integrated gimbal structure and features that are useful for attaching PZT (Pb(Zr_xTi_1-x)0₃) strips. Under a 30 V applied voltage, the PZT strips stretch the suspension, producing an effective 1.3 μm magnetic head radial motion. The suspension has an in-situ piezoresistive film, which produces a signal proportional to the in-plane suspension bending. This signal can be used as an additional relative position error signal, which greatly improves the robustness of the track-following HDD servo. Microfabrication techniques, suitable for fabricating this high performance one-pieced silicon suspension, are also presented