Quasi-shear mode piezoelectric microactuator for head-based servo control in hard disk drives

Dual-stage actuation is an important technology enabler for advancing hard disk drive (HDD) capacity and performance. With smaller track pitches and larger disturbances due to increased spindle speeds, future dualstage actuators will need to overcome the bandwidth limitations faced by the current suspension-based devices. The proposed quasi-shear mode piezoelectric microactuator provides a cost-effective solution which can be implemented at the wafer-scale. We demonstrate a prototype with a measured stroke of 1.6 nm/V at 50 kHz. Furthermore, a second actuation mode is proposed to minimize pressure loss at the air-bearing surface by independently controlling the necessary gap width between the slider body and read/write head.