Performance Evaluation using Laser Doppler Vibrometer Sensing Technique on Advanced Lead Magnesium Niobate-Lead Titanate Piezoelectric-Material-Based Microactuator for Hard Drive Head
Parinya Wattananukulchai and Don Isarakorn
(Received December 15, 2017; Accepted February 13, 2018)
Keywords: PZT, PMN-PT, HDD, HGA, TPI, resonance, stroke
This paper presents a microactuator for dual-stage actuator of hard disk drive (HDD) based on lead magnesium niobate-lead titanate (PMN-PT) piezoelectric material and a comparative evaluation of its performance versus that of traditional lead zirconate titanate (PZT) microactuator using the Laser Doppler Vibrometer (LDV) sensing technique. PZT microactuator technology has commonly been implemented in the read/write (R/W) magnetic head of HDD. It has a significant function: it moves the magnetic head rapidly and accurately. In order to achieve both accurate positioning control on data tracks and high-speed access across another data track, advanced high-performance actuator and servo control technologies are necessary. Actuator with a wide stroke travel range is essential for HDD as it gives a high-speed access performance. In this study, we focused on comparing the proposed dual-stage PMN-PT head-based actuator with existing PZT actuator that were mounted on a commercial head gimbal assembly (HGA) by LDV to see whether it could be a worthy replacement for the traditional PZT microactuator. The experimental results show that the proposed PMN-PT micro-actuator provided more than twofold improvement in a stroke travel of R/W head. Moreover, its dynamic behavior was suitable for assembling into high density hard disk drive of the future for big data storage without any needs to redesign the HGA nor to costly invest in the new assembling machines in a production line. The comparative data of dynamic and static behaviors of PMN-PT versus PZT obtained in this study may be put to good use by sensor designers. Moreover, for many cyber-physical system designers, our data may make them take interest in PMN-PT as a better-performing sensor and actuator for their systems.
Corresponding author: Don Isarakorn