Role of nonlinearity and chaos on RF-MEMS structural dynamics

Among RF-MEMS layouts currently used for designing microswitches, microresonators and varactors, cantilever and double clamped microbeams are widely applied in industrial applications. After a consistent modelling activity which defined suitable numerical approaches to study the static behaviour of such microdevices, authors investigate here the problem of nonlinear electromechanical coupled non-symmetric microactuators, used in RF application to complete the analysis of their dynamic behaviour. In particular, while effects of frequency shifting, amplitude jumping and geometrical nonlinearity were already deeply modelled and investigated, in this work the prediction of nonlinear response and eventual chaos in repetitive actuation of these devices is dealt with. This is required for an effective prediction of fatigue too. This paper shows a computational approach to run simulations in time domain, fairly quickly, in presence of all the above mentioned aspects and some examples of chaos growing in dynamic response, accordingly to the operation boundary conditions.