Dynamic analysis of a bistable compliant micro-mechanism

This paper presents an investigation on the dynamic characteristics of a bistable compliant micro-mechanism. The analyzed bistable mechanism has two stationary positions at the two extremes of the motion range, where the strain energy is local minimum. In this study, a bistable compliant micromechanism was first designed based on the functional needs of an optical switch that was considered as a tentative design goal. The central mass of the micro-mechanism was treated as a carriage to carry switching components, such as mirror, electrical contact, etc. The bistable compliant micro-mechanism was modeled as a double-slider mechanism without loss of generosity. Equations governing the motion, strain energy and stress states of the mechanism system were derived as a basis for design and analysis. Furthermore, the dynamic behaviors were calculated by both pseudo-rigid-body and finite element method. In order to verify the correctness of theoretical prediction on the dynamic characteristics, the designed micro-mechanisms were fabricated by MUMPs(TM) provided by Cronos Integrated Microsystems. In addition, a test rig incorporating with required instruments was then constructed for measuring the performance of the bistable micro-mechanism. From the experimental study, it revealed that good agreement between analytical and experimental results were obtained.