Pull-in instability of cantilever and fixed–fixed nano-switches

In this article, pull-in instability of cantilever and fixed–fixed nano-switches subjected to electrostatic forces produced by an applied voltage, and intermolecular forces are investigated. A linear distributed load model is considered to approximately model the nonlinear intermolecular and electrostatic interactions acting on the nano-beam. The effect of small length-scale is taken into account using hybrid nonlocal Euler–Bernoulli beam model. The effects of small length-scale on the pull-in instability and freestanding behavior of the cantilever and fixed–fixed nano-beams are presented and compared with the Eringenʹs nonlocal and classical beam models. It is found that the Eringenʹs nonlocal beam model produces unreasonable pull-in voltages, minimum gaps and detachment lengths. It is shown that shortcomings of the Eringenʹs nonlocal beam theory can be resolved by using hybrid nonlocal beam model.