An iterative method for estimating the pull-in parameters of electrostatic actuators

摘要

Performance of electrostatic actuators used in MEMS devices is severely limited by the stability considerations that are related to the pull-in parameters. The static and dynamic responses of electrostatic actuators driven by single as well as multiple voltage excitations are studied with an aim of estimating these pull-in voltage and distance parameters. A normalized Hamiltonian formulation is adopted and the resulting equations are solved analytically and also numerically using an iterative scheme. Recently a numerical a-line method has been proposed to extract the pull-in parameters. Scanning along the a-lines by voltage and displacement iteration schemes were studied. Estimating the intersection of the a-lines with the pull-in hypersurface indicates maximal voltage variable. We revisit these two iteration schemes and propose few insights to improve the convergence. Convergence of the parameters to the theoretical values is found to be smooth. This approach helps us to generalize the technique for more complicated geometries.