Investigation of the vdW Force-Induced Instability in Nano-scale Actuators Fabricated form Cylindrical Nanowires

The presence of van der Waals (vdW) force can lead to mechanical instability in freestanding nano-scale actuators. Most of the previous researches in this area have exclusively focused on modeling the instability in actuators with one actuating components. While, less attention has been paid to actuators consist of two actuating components. Herein, the effect of the vdW force on the instability of freestanding actuators with two parallel actuating components is investigated. Conventional configurations including cantilever and double-clamped geometries are investigated. A continuum mechanics theory in conjunction with Euler-beam model is applied to obtain governing equations of the systems. The nonlinear governing equations of the actuators are solved using two different approaches, i.e. the modified Adomian decomposition and the finite difference method. The maximum length of the nanowire and minimum initial gap which prevents the instability is computed.