高密度硬磁盘用小型压电致动器

Mini Piezoelectric Actuator for Rigid Disk Drives with High Track Density

利用宽度弯曲振动模式，制成了平面分割电极型片状压电致动器．分析、测试了致动器的位移－驱动电压特性和谐振频率．典型结果是１２Ｖ驱动电压下可获得０．４６μｍ的位移量，谐振频率为１０．７ｋＨｚ．

Rigid disk drive will have track density of the order of 25 000 track per inch in few years. This would require a servo bandwidth of head positioning system of at least 3 kHz. The increase in bandwidth, however, is limited by the presence of mechanical resonance modes and other nonlinearities in the voice coil motor (VCM) actuators. A dual stage servo system may be needed to achieve such a high track densities. This would involve a high bandwidth microactuator for rapid position corrections of the recording head, coupled with a conventional VCM actuator. This paper presents a planar piezoelectric actuator. This new type of split electric actuator is based on width bending mode. It has a high bandwidth, large displacement and simple structure. The displacement driving voltage characteristics and resonance frequency of the actuator were studied. Typically, the mini actuator generates 0.46 μm displacement under 12 V driving voltage. The primary resonance frequency is about 10.7 kHz. The results show that the new actuator can be used as a fine tunning for locating the recording head in the dual stage servo system .