Piezoelectric piggy-back microactuator for hard disk drive

A new piezoelectric piggy-back microactuator for high density hard disk drives was designed and fabricated to achieve more accurate positioning of the magnetic head and increasing servo bandwidth. The microactuator is made of stiff piezoelectric ceramic material to actuate the slider on which the head-element is formed. It is designed to amplify the actuating displacement. The basic mechanical performance of the microactuator was evaluated. The stroke of displacement was ±0.5 μm with a drive voltage of ±lO V and a dc bias of +10 V. The resonant frequency of the microactuator was high at 34 kHz. The fundamental resonant frequency of an assembled head with microactuator was high at around 20 kHz. The head variation was suppressed to O.1 μm by the microactuator with feedback control. These results suggest the feasibility of increasing servo bandwidth up to several kHz and positioning the head more precisely