Self-latched micromachined mechanism with large displacement ratio

A self-latched micromachined mechanism with large displacement ratio is presented in this paper. The large output displacement is obtained by amplifying the small input motion through the elastic deformation of the compliant configuration, which realizes the self-latched output by local bifurcation effect. The design theory and synthesis of compliant microstructures are analyzed. The numerical and analytical simulations are implemented to the linear amplification, which shows that as high as >50 times displacement magnification can be obtained. Self-latching is realized by bifurcation effect to maintain fixed output displacement even though the input goes further as indicated by the large displacement simulation. This micromachined mechanism along with a comb-drive actuator is fabricated by deep-reactive ion-etching (DRIE) process. In experiment, it measures an output displacement of 52.0 μm at an input displacement of only 0.96 μm, obtaining a displacement ratio of 54.2. For further input displacement, the output displacement remains unchanged, proving the self-latching effect.