Effect of geometrical nonlinearity on MEMS thermoelastic damping

Although the thermoelastic damping is a direct consequence of thermodynamic relations, its influence in macroscopic systems can be considered as negligible. This is not the case in microscopic devices, where this effect can be, for instance, one of the main causes that limit the quality factor of MicroElectroMechanical Systems (MEMS) resonators. Besides showing why it is important to introduce the thermoelastic damping in the design of MEMS, we present simulation results that demonstrate the differences that appear when a realistic nonlinear analysis is considered instead of using a linear approximation. Thus, we show how the nonlinearities due to large displacements impact the oscillation frequency as well as the decay time of displacements and energy for a MEMS cantilever. (C) 2008 Elsevier Ltd. All rights reserved.