Dynamical characteristics of an electrically actuated microbeam under the effects of squeeze-film and thermoelastic damping

The static and dynamic behavior of a MEMS subjected to thermoelastic and squeeze-film effects is investigated. We analyse the various engineering aspects which interact in a slender fixed–fixed microbeam; major attention is devoted to the modeling of such a multiphysics system, including the mechanical, electrical, thermoelastic and fluid-dynamic properties with their couplings. The static solution is obtained numerically by a finite-difference technique. The variation of the static deflection with respect to the voltage increment, in the presence of geometric nonlinearites, is studied first. Numerical results on the magnitude of thermoelastic damping (TED) and squeeze-film damping are obtained and examined with a parametric analysis. The effect of different relaxation times imposed on the TED, both in pull-in and non pull-in regime, is studied. The squeeze-film damping is modeled by means of the Reynolds equation and the large pressure regime is investigated. We then present a comparison between the different sources of damping, evaluating their relative contribution to the system.