Nonlinear nonlocal pull-in instability of boron nitride nanoswitches

In the present study, nonlinear pull-in instability of boron nitride nanoswitches (BNNSs) subjected to electrostatic and van der Waals (vdW) forces is investigated. Based on Euler-Bernoulli beam theory, von Karman geometric nonlinearity, nonlocal piezoelasticity theory and the principle of virtual work, the governing equations are obtained. The differential quadrature method is employed to discretize the nonlinear governing equations, which are then solved by a direct iterative method to obtain the nonlinear pull-in and pull-out voltages for cantilever and fixed-fixed boundary conditions. A detailed parametric study is conducted to elucidate the influences of nonlocal parameter, vdW force, fringing field, beam length and gap distance on the behavior of the pull-in instability voltage. Numerical results indicate that the magnitude of the pull-in voltage increases with increase in the gap distance. Furthermore, as the effective gap distance increases, the pull-out voltage tends toward the electrostatically pull-out voltage.