Piezoelectric piggy-back microactuator for hard disk drive

Piggyback Microactuators for Ultra-high Track Density Hard Disk Drives

“…Another advantage is that it can use a conventional slider, so there is no influence on either the thin-film magnetic head process or the air-bearing dynamics of the slider to maintain a stable low flying height compared with the head-element moving type actuation (third-generation). Currently, various types of microactuators for moving the slider have been developed, for instance, electrostatic actuator [2±4] and piezoelectric actuator [5]. Comparing the piezoelectric actuator with the electrostatic actuator, the typical advantages are the high resonant property and large actuating force due to the high-stiffness piezoelectric material.…”

“…To achieve the low drive voltage, the beam parts comprise a multi- Figure 17.12. Schematic diagram of the microactuator and HDD head assembly [5]. layer structure.…”

“…The displacement was measured on the side Figure 17.14. Stroke of displacement of the microactuator vs. drive voltage [5]. surface of the slider, which corresponds to the position of the head element.…”

Guest Editorial Introduction to the Focused Section on Electromagnetic Devices for Precision Engineering

“…One of the key technological limitations of VCAs is its low bandwidth, which prevents fast positioning of the read-write head thereby limiting its data-access speed. As the track density of an HDD increased dramatically to accommodate more data per unit area than earlier, dual-stage actuators (DSAs) have been introduced since the 1990s [38], [48]- [51]. In these DSAs, piezoelectric actuators or microelectromechanical systems-based actuators are employed to generate highprecision motions, and recently the piezoelectric actuator has become a workhorse in precision engineering with various applications [52]- [55].…”

Newly Designed Slider-Based Micro-Actuator for Magnetic Disk Drive

“…Typically, dual-stage servo system for magnetic disk drive comprises a conventional voice coil motor, as primary actuator, and a micro-actuator, as secondary actuator for more precise movement. Micro-actuator of dual-stage servo system could be generally classified into three different types, according to the position where the actuator is placed, they are: suspension-based (1) , slider-based (2) , and head-based type (3) .…”