Dynamics of the Microresonator in the Regime of Supercritical Compression

In this work we investigate nonlinear dynamics of an electrostatically actuated microbeam resonator, located between two stationary electrodes, in the regime of supercritical compression. Longitudinal movement of the elastic fastening creates a longitudinal force in the elastic element of the microresonator. The equations of motion of the resonator are supplemented by equations of electrical circuits containing sources of electromotive force and capacitors of variable capacitance formed by fixed electrodes and the elastic element of the resonator. Equilibrium positions depending on the longitudinal displacement of the elastic fastening mechanism are obtained for various configurations of the electric field. With different switched on sources of constant electromotive force either two or three critical values of the force are possible, which differ from the Euler force. A numerical experiment demonstrating the possibility of the occurrence of a self-oscillatory regime was performed.