Department of Mechanical and Materials Engineering, The University of Western Ontario, London, ON, N6A 5B9, Canada.
Nanotechnology. 2010 Dec 17;21(50):505708. doi: 10.1088/0957-4484/21/50/505708. Epub 2010 Nov 23.
The influence of surface effects, including residual surface stress and surface elasticity, on the pull-in instability of electrostatic switches in nanoelectromechanical systems (NEMS) is studied using an Euler-Bernoulli beam model. This model is inherently nonlinear due to the driving electrostatic force and Casimir force which become dominant at the nanoscale. Since no exact solutions are available for the resulting nonlinear differential equation, He's homotopy perturbation method (HPM) is used to get the approximate analytical solutions to the static bending of NEMS switches, which are validated by numerical solutions of the finite difference method (FDM). The results demonstrate that surface effects play a significant role in the selection of basic design parameters of NEMS switches, such as static deflection, pull-in voltage and detachment length. Surface effects on low-voltage actuation windows are also characterized for these switches. The present study is envisaged to provide useful insights for the design of NEMS switches.
采用 Euler-Bernoulli 梁模型研究了表面效应（包括残余表面应力和表面弹性）对纳机电系统（NEMS）静电开关吸合不稳定性的影响。由于驱动静电和 Casimir 力在纳米尺度上变得占主导地位，该模型本质上是非线性的。由于没有针对由此产生的非线性微分方程的精确解，因此使用 He 的同伦摄动法（HPM）来获得 NEMS 开关静态弯曲的近似解析解，并用有限差分法（FDM）的数值解进行验证。结果表明，表面效应对 NEMS 开关基本设计参数（如静态挠度、吸合电压和脱离长度）的选择有重要影响。还对这些开关的低压致动窗口的表面效应进行了特征描述。本研究旨在为 NEMS 开关的设计提供有用的见解。
