A comparative study based on classical and newer piezoelectric materials based unimorph actuators for Hard Disk Drive

The piezoelectric actuator technology for moving the read-write head of Hard Disk Drive (HDD) is very important and widely used. Advanced high-performance technologies for the actuator and servo control are required in order to achieve not only accurate positioning control on data tracks but also high-speed access onto another data track. There is strong demand for hard disk drives with high-speed access performance, which generally requires actuators with a wider servo bandwidth. This paper focuses on the comparative piezoelectric materials based unimorph actuators with classical piezo (Poly crystalline PZT) and newer piezo (Single-crystalline PMN-PT) ceramics. The advantages of piezoelectric materials in terms of mechanical and electrical characteristics aiming at a useful compromise performance displacement and resonant frequency are studied and analyzed.