A MEMS Fishbone-Shaped Electrostatic Double-Ended Tuning Fork Resonator With Selectable Higher Modes

In this paper, a microelectromechanical systems fishbone-shaped electrostatic double-ended tuning fork (DETF) resonator with selectable higher modes is presented. The resonator can realize ten vibration modes with resonant frequencies from 137.929 to 913.476 kHz and multi-mode selection function. Different from conventional electrostatic actuation methods, the proposed fishbone-shaped structure combined with tooth-shaped electrode generates bending moment on the beam and leads to vibration of the DETF. The vibration mode and the resonant frequency can be selected and measured according to the configuration of electrodes. Consequently, the proposed fishbone-shaped DETF resonator can provide multi-mode vibration and variable resonant frequency. The device is fabricated by the silicon-on-insulator process and tested via open-loop spectral response measurement. Finally, electrical parameters of the equivalent circuit model are extracted for further research.