Theory and Experimental Demonstration of Symmetrically Bistable MEMS Pin-Joint Buckled Beam

In-plane moving MEMS bistable elements with symmetrical stable states can be realized using post-process compression of a straight beam to be made buckle. This paper derives and experimentally demonstrates an analytical theory of this element. Design parameters of the component structures, a buckling beam, supporting arms, and compression mechanisms with a receptacle that can be made flexible are related to the behavior including the beam’s profile, the force required to make a flip to the other state, and the displacement where the flip happens. Test devices were fabricated using the silicon-on-insulator MEMS technique and their response to an electrostatic attraction was measured. The experimental results matched the developed theory. The theory and the experimental results presented in this paper can facilitate the introduction of symmetrical bistable structures as a new mechanical element in future MEMS devices. [2025-0002]