Nonlinear behaviour of electrostatically actuated carbon nanotube-based devices

Abstract

In this paper nonlinear behaviour of electrostatically actuated carbon nanotubes (CNTs) is investigated. The model comprises a clamped–clamped CNT suspended over a graphite ground electrode plate from which a potential difference is imposed. The actuation is based on ac and dc applied voltages and it is assumed that the neutral axis of bending is stretched when the beam is deflected, and also, the interatomic interaction forces between CNT and ground plate are considered. The versatile Galerkin's method is employed to reduce the nonlinear integral-partial-differential equation of motion to a nonlinear ordinary differential equation in time, and then, the reduced equation is solved by direct numerical integration. In the dc voltage actuation case, the pull-in/pull-out phenomena, hysteresis characteristic, pull-in time duration and the response of the system are studied. The obtained results are compared with the molecular dynamics method. Eventually, a nano-switch immune to input noise is proposed, which relies on the hysteresis characteristic of the system. In combined ac and dc voltage actuations, the vibrational behaviour and nonlinear frequency response of nano-resonator are studied.