Lifetime prediction method for piggyback PZT actuator

The experimental lifetime predictive equation for a piggyback PZT actuator was derived. A piggyback actuator is a fine actuator of a dual-stage servo system that is essential to increase the recording density of hard disk drives (HDD's). The obtained equation agrees with Arrhenius' equation. The lifetime of our developed actuator was estimated to be longer than 5 years under heavy use conditions. This lifetime prediction method is useful for designing piggyback PZT actuators for high-performance HDD's.