A Three Degree-of-Freedom Model for Self-Retracting Fully Compliant Bistable Micromechanisms

摘要

A three degree-of-freedom (3DOF) pseudo-rigid-body model (PRBM) has been developed and used in the design of a new class of self-retracting fully compliant bistable micro-mechanism (SRFBM). The SRFBM provides small-displacement linear travel bistability and is suitable for low-power microswitching applications. The design process involved a combination of single and multiple degree-of-freedom PRBM and finite element models to quickly proceed from a concept rigid-body mechanism to fully compliant fabrication-ready geometry. The 3DOF model presented here was developed to more accurately model the behavior of the tensural pivots-a new class of compliant segment used to avoid combined compressive loading of flexible segments. Four SRFBM designs were fabricated and tested for bistability, on-chip actuation, critical force, and fatigue tests. These tests validate the models used in the design process and demonstrate the functionality and reliability of the SRFBM.