Published online by Cambridge University Press: 22 March 2012
In this paper, the deflection, natural frequency and damping quality factor of a viscoelastic microplate under an electrostatic actuation are investigated. The microplate is assumed as a CNT-reinforced nanocomposite microplate, and an electrostatic actuation is applied on it. The nonlinear equations of motion are derived using the Von-Karman plate theory, and the Kelvin-Voigt viscoelastic model. In order to obtain the material properties of the nanocomposite microplate, the Eshelby–Mori–Tanaka method is implemented. The static pull-in instability of the microplate is obtained. It is shown that the nanocomposite microplate can both increase the deflection and natural frequency of the micro devices. So, one may have a nanocomposite microplate with the same deflection of the SiO2 microplate, while its frequency would be 1.45 times of the SiO2 microplate. This characteristic is highly desirable in microswitches. Also, it is shown that the damping quality factor of the nanocomposite microplate is much greater than SiO2 microplate. This fact limits the implementation of a nanocomposite microplate as a vibrating element of the micro devises. So, there are great beneficial static and frequency response characteristics for nanocomposite microplates. But, it is not recommended for microresonators due to high damping characteristics.