Fluid damping phenomena in a slender microbeam modelled on nonclassical theory

This work deals with the evaluation of the squeeze-film damping in an electrically-actuated microbeam considering the effects of an imposed static deflection. The model presents a reliable modelling of the mechanical behaviour by improving the classical approach with the features of the strain-gradient elasticity theory. Taking into account a correction of the electric actuation for the fringing field effects, a parametric analysis is performed. The work pays attention to evaluate the damping force on the beam surface both in small static deflection regime and near the static pull-in. The results show that the correction for the finiteness of beam edges and the high-order material parameters affect the response only at large deflections. A brief study on the static behaviour is carried out highlighting how the response is affected by the strain-gradient elasticity theory. A parametric analysis of the damping force is presented and the properties of the cut-off point are studied.