In order to overcome the loss of performances issue when scaling resonant sensors down toNEMS, it proves extremely useful to study the behavior of resonators up to largedisplacements and hence high nonlinearities. A comprehensive nonlinear multiphysics modelbased on the Euler-Bernoulli equation which includes both mechanical and electrostaticnonlinearities in the case of a capacitive doubly clamped beam is presented. This purelyanalytical model captures all the nonlinear phenomena present in NEMS resonatorselectrostatically actuated including bistability, multistability which can lead to severalphysical limitations such as noise mixing, frequency stability deterioration as well asdynamic pull-in. Moreover, close-form expressions of the critical amplitudes and pull-indomain initiation amplitude are provided which can potentially serve for NEMS designers asquick design rules.
