Active-head slider with piezoelectric actuator using shear-mode deformation

The active-head slider technology for hard disk drive is one of the most promising means to decrease flying height. This paper describes a piezoelectric flying height control slider which has a faster dynamic response compared with conventional active-head sliders. This slider can be also adapted to the conventional slider-fabrication process. PZT layer located near the magnetic head has shear mode deformation by applying electric voltage between the upper and lower electrodes when the flying height of magnetic head needs to be decreased or increased. We fabricated a prototype with single crystal Si substrate for feasibility study. Our evaluation of the prototype revealed that the piezoelectric constant of the shear mode deformation was 0.88 nm/V, and the dynamic response was 50 kHz. The shape of the air bearing surface was optimized by simulations using a robust design method. We found that the stroke was 8 nm for an applied voltage of 11 V if the flying height was 11 nm with no deformation in PZT.