Impedance spectroscopy of electrostatically driven MEMS resonators

The electrical response of vibrating, electrostatically driven microelectromechanical and nanoelectromechanical system (MEMS and NEMS) devices was measured electrically using impedance spectroscopy. A physical model of this structure was elaborated, allowing us to predict the electrical response based on the dimensions and mechanical properties of the structure as well as the measurement conditions. This result was correlated with the results of the electrical equivalent circuit model. The physical model predicted that the magnitude of the electrical response is inversely proportional to the distance between the electrodes to the power of 4. Such a strong dependence was verified experimentally using a vibrating electrostatically driven MEMS operating in vacuum. The verified physical model is suitable for optimization of MEMS structures designed for electrical detection of vibrations.