Microelectromechanical Converter Performance under Random Multiple-Frequency Vibrations

An analysis of electrostatic three-electrode double-capacitor microelectromechanical (MEM) converter performance under random excitation taking into consideration the interaction between mechanical and electrical forces is carried out. A method for estimation of the converter parameters under random excitation is proposed. Evaluations of the converter output power for two different excitation sources are performed. It has been established that even with the quasi-harmonic nature of mechanical vibrations, taking into account the distribution of their power in the frequency band significantly increases the accuracy of the MEM converter electrical parameters evaluation. It has been shown that in spite of decreasing vibration amplitude as the frequency increases the contribution of the high-frequency oscillations to the electrical power of the MEM converter remains significant. An analysis of the converter under harmonic excitation is probably possible only during preliminary design. While the device structure has to be optimized taking into account the stochastic behaviour of mechanical vibrations, and the realistic frequency distribution of an input excitation power.