Snap-action bistable micromechanism actuated by nonlinear resonance

Abstract—This paper presents analysis, design, realization, and experimental demonstration of a bistable switch actuated dynam-ically utilizing mechanical resonance phenomenon. We demon-strated that if a bistable structure is driven into a resonance near one of its states, it may achieve a large enough amplitude of vibration, sufficient to switch between its stable states. Using energy analysis, we concluded that dynamic switching of bistable structures may provide significant energy advantages over con-ventional static-switching approaches. To confirm the results, we derived analytically the closed-form actuation conditions guaran-teeing switching between the states of a bistable structure and applied these conditions to experimental devices. Micromachined prototypes of dynamically actuated bistable switches were de-signed, fabricated, and characterized. We demonstrated experi-mentally that resonant dynamic switching provides energy saving of around 60 % at atmospheric pressure with proportional increase in efficiency as the pressure decreases. [2008-0057] Index Terms—Bistability, dynamic snapping, nonlinear resonance. I