Shock test and analysis of assembled suspension with microactuators in hard disk drives

A dual-stage servo system using enhanced active-passive hybrid piezoelectric actuators has been developed for improving existing dual-stage piezoelectric actuators for higher precision positioning and shock resistance, due to the incorporation of passive damping in the design. In this paper, an assembled suspension with three different configurations of microactuators is investigated via shock test and analysis. In the shock test, the assembled suspension with microactuators, which is fixed on a stage mounted on a linear shock machine, is excited under half sine shock impulses provided from the machine. The shock responses are measured by extracting the deformation of the assembled suspension with using a strain gauge attached on it during the shock excitations. The strain responses of the assembled suspension with microactuators are compared to evaluate their shock resistance performances. The experimental and simulation results show the effectiveness of viscoelastic damping layers used in the design of active-passive microactuators. Moreover, the test results also show the enhanced active-passive hybrid piezoelectric actuators would outperform the other cases under the high g shock excitations.