dynamic pullin instability of nanoactuators in the presence of a dielectric layer

The natural frequency and pullin instability of clampedclamped nanoactuators in the presence of a dielectric layer are analyzed. the influence of the presence of casimir force, electrostatic force, fringing field effect, axial force, stretching effects and the size effect are taken into account. the governing equation of the dynamic response of the actuator is transformed in a nondimensional form. the galerkin decomposition method is employed to decompose the equations in time and space. then, the obtained decomposed governing equations are solved numerically. the results show that the presence of the size effect and the axial force increases the natural frequency of the system. it is found that there is a unique value of the dielectric layer, in which the pullin deflections of the nanoactuators are independent of the casimir force, size effect and the axial loads. the advantage of this dielectric layer can be utilized in the design of nanoactuators and nanosensors in the nanoscale.