Dynamic release condition in latched curved micro beams

Abstract

Curved bistable beams subjected to transverse loading may exhibit latching, namely remain in their buckled state under zero force. Under such circumstances, an opposite force is required for snapping-back (release) of the beam to its initial configuration. For an electrostatically actuated beam, two electrodes located at either side of the beam may therefore be required for bidirectional actuation. In this study, a release procedure conducted by the same electrode, which is used for the snapping, is considered. The approach involves preloading of the latched beam using electrostatic force, followed by a sudden release of the voltage and snapping back motion. A reduced order (RO) model, resulting from the Galerkin decomposition with buckling modes of a straight beam as base functions is used for the formulation of a necessary release condition, which is then verified numerically.