An active-head slider with a piezoelectric actuator for controlling flying height

Abstract

The current design of magnetic-disk head sliders needs an extra margin of flying height for manufacturing tolerance or environmental variation. To reduce this margin, we have developed active-head sliders. These sliders carry an unimorph piezoelectric microactuator, and their flying height can be controlled. After simulating the piezoelectric deflection of the actuator and flying characteristics of air-bearing surfaces, we designed two types of active-head sliders (five-pad type and four-pad type) and fabricated them by silicon microelectromechanical system (MEMS) processing. In tests, the sliders flew over a glass disk, and the observed stroke of the actuator (30 nm/5 V) was considered large enough to control the flying height. The large area at the rear end of the four-pad-type slider structure is sufficient to carry conventional read/write heads. Moreover, the slider fabrication process will not destroy the heads. We, thus, conclude that the active-head sliders can be applied for practical use easily, and their flying height will be significantly lower than that of conventional disk head sliders.