Fully compliant tensural bistable micromechanisms (FTBM)

A new class of bistable mechanisms, the fully compliant tensural bistable micromechanism (FTBM) class, is introduced. The class consists of linear bistable micromechanisms that undergo tension loads, in addition to the bending loads present, through their range of motion. Proof-of-concept designs fabricated in two different microelectromechanical systems (MEMS) surface micromachining processes were demonstrated. Three sets of refined designs within the FTBM class were designed using optimization methods linked with nonlinear finite element analysis (FEA), then fabricated and tested. Measured force and displacement performance are compared to values obtained by FEA. On-chip actuation of the bistable mechanisms was achieved using thermomechanical in-plane microactuators (TIMs). The FTBM class of bistable mechanisms explores a relatively new design space for fully compliant micromechanisms, and mechanisms from this class have promise in such applications as micro shutter positioning, microvalves, and electrical microrelays.