Quantification of Uncertainty in Creep Failure of RF-MEMS Switches.

We present simulations of the failure of radio-frequency micro-electro-mechanical systems switches due to diffusional creep that include the quantification of uncertainty in the geometry, material parameters, and residual stress. The switch is modeled as an Euler–Bernoulli beam that is actuated electrostatically in a fluid medium. The fluid damping is modeled by a squeeze-film model and the beam model incorporates stretching nonlinearity in addition to Coble creep. The resulting nonlinear dynamic model is solved using a Ritz–Galerkin-based modal expansion and explicit time integration. The focus of this paper is on the effect of creep as a failure mechanism and the implications of uncertainty in the device geometry, material parameters, and boundary conditions. The degradation of the device performance is evidenced by decreases in the pull-in voltage, the pull-out voltage, and the impact velocity. We find that the variability in the experimentally measured pull-in voltage is accounted for by the inclusion of uncertainty in the material and geometric properties. [2015-0191] [ABSTRACT FROM PUBLISHER]