Theoretical study of the effect of Casimir attraction on the pull-in behavior of beam-type NEMS using modified Adomian method

In this paper, modified Adomian decomposition (MAD) is introduced to investigate the effect of the Casimir attraction on pull-in instability of beam-type NEMS theoretically. Two engineering cases including cantilever and double cantilever nano-beam are considered. The proposed MAD method is employed to solve the nonlinear constitutive equation of nano-beams. The basic engineering parameters such as critical deflection and pull-in voltage of nano-beams are computed. It is found that the Casimir forces decrease the pull-in deflection and voltage of nano-beams. On the other hand, the fringing field increases the pull-in deflection while decreases the pull-in voltage of the actuators. As a special case in this work, the instability of freestanding nano-beams is investigated due to the Casimir attraction. The analytical MAD solutions are compared with numerical ones and lumped model, as well as other methods in the literature. (C) 2010 Elsevier B.V. All rights reserved.