Design, fabrication and characterization of a buckled beam actuator for micro-displacement applications

Buckled beam-based bistable actuators are the key for contactless digital actuation. In this paper, the design, fabrication and characterization of bistable buckled beams is presented. A series of structures based on pre-shaped buckled beams of lengths ranging from 2 to 4 mm, a constant width of 5 um and an actuation stroke ranging from 20 to 100 um was fabricated. Experimental data show a significant difference with classical model predictions, mainly because the actuation method results in a displacement which is a combination of several buckling modes. Thus the model commonly used for buckled beams design has then been modified in order to take into account the beam shape effectively fabricated and experimental results. An accurate model was obtained, enabling good prediction of the experimental switching behavior of microfabricated buckled beams.