Abstract
An increasing number of micro-devices have been designed with compliant hinges and joints to prevent friction and clearance. Furthermore, by proper design this kind of micro devices can possess two stable positions at the two extremes of the motion range, which may be named as bistable compliant mechanism. Bistable mechanisms are excellent for the application of switching devices because they do not consume energy to hold the mechanism in place at the stable positions.This thesis presents an investigation into the design and dynamic analysis of a bistable compliant micro-mechanism. The dimensions of the bistable compliant mechanism have been decided by optimization techniques. The objective function is to minimize the actuation force in switching between two stable positions. However, the constrained functions contain the fracture strength, existence of bistable behaviors and fabrications. For the application of high operation frequency the dynamic analysis of the bistable compliant mechanism is necessary. Therefore, the modal analysis defining the range of operation frequency for keeping the central mass in straight-line motion is analyzed first. Then, the time of flight between two stable positions is computed from the derived dynamic equations. Finally, the nonlinear transient response analysis at the stable positions has been done by Runge-Kutta computation procedure. The bistable compliant mechanism actuated by thermal actuator arrays is fabricated by MUMPsTM provided by Cronos Integrated Microsystems.