Surface effect on the pull-in instability of cantilevered nano-switches based on a full nonlinear model

• A full nonlinear model is developed for cantilevered nano-switches.
• The current theoretical model is validated by experimental results.
• The residual surface stress significantly affects the pull-in voltages.
• The dynamic pull-in behavior is remarkably affected by the residual surface stress.

The aim of this paper is to develop a full nonlinear model for electrically actuated nanocantilever-based NEMS and to explore its pull-in instability as well as nonlinear dynamic responses based on the surface elasticity theory, with consideration of both the geometric and inertial nonlinearities. The developed nonlinear model is validated by the previous experiment. Then the static pull-in behavior of the nano-switch is investigated, showing that the surface effect has a significant impact on the pull-in voltage. Considering a time-dependent harmonic component superposed on the DC voltage, the frequency–response curves are presented for describing the dynamic pull-in behaviors of the nano-switch. The results show that the cantilevered nanobeam would display either hardening-type or softening-type nonlinear behavior, depending on the sign symbol of the residual surface stress. In particular, it is indicated that the surface effect on the unstable parameter region of dynamic pull-in instabilities of the nano-switch is significant.

A full nonlinear model for cantilevered nano-switches with consideration of surface effect and both geometric and inertial nonlinearities is developed and the dynamic pull-in instability is analyzed.Figure optionsDownload as PowerPoint slide