Robust design of a microactuator for HDD head positioning

Abstract

With rapid growth in areal recording density of hard disk drive (HDD), ultra-high precise head positioning and higher servo bandwidth are required. Dual-stage actuation system using MEMS actuator has been considered as one promising precise positioning solution. The microacatuator we designed has a low in-plane resonant frequency, which limits the servo bandwidth and needs compensation by servo control system. However, this resonant frequency may shift from its mean value during MEMS fabrication process. This shift adds difficulty to effective compensation for servo control. In this paper, a robust solution is proposed to minimize microactuator's resonant frequency shift so that its first resonance frequency is insensitive to the effects of sources of processing variations and then effective compensation for high servo bandwidth can be achieved. © Springer-Verlag 2005.