Size-dependent snap-through and pull-in instabilities of initially curved pre-stressed electrostatic nano-bridges

Abstract

This study investigates the electromechanical instabilities of micro/nanobeams with initial curved shape and subjected to electrostatic field and Casimir intermolecular force. Using modified couple stress theory and the principle of minimum potential energy and variational approach, the nonlinear equations associated with boundary conditions are derived. The generalized differential quadrature (GDQ) method is used to discretize the equations and boundary conditions, and then the discretized form of equations are solved numerically. In the end, the impacts of fringing field effect, beam imperfection and size effect on microbeam are investigated and the results are compared with experimental results. Besides, in the end the effect of Casimir intermolecular force in initially curved nanobeams and its symmetric and asymmetric effects on snap-through and pull-in instabilities are discussed.