Design of two-link, in-plane, bistable compliant micro-mechanisms

A bistable mechanism has two stable states within its range of motion. Its advantages include the ability to stay in two positions without power input and despite small external disturbances. Therefore, bistable micro-mechani sms could allow the creation of MEMS with improved energy efficiency and po sitioning accuracy This paper presents bistable micro-mechanisms which func tion within the plane of fabrication. These bistable mechanisms, called "Yo ung" bistable mechanisms, obtain their energy storage characteristics from the deflection of two compliant members. They have two pin joints connected to the substrate, and can be constructed of two layers of polysilicon. The pseudo-rigid-body model is used to analyze and design these mechanisms. Th is approach allows greater freedom and flexibility in the design process. T he mechanisms were fabricated and tested to demonstrate their bistable beha vior and to determine the repeatability of their stable positions.