| 研究実績の概要 |
This research introduces a novel triple mass resonator (TMR) and a two-axis symmetric resonator with multiple proof masses for improving stiffness sensitivity and tuning capability of MEMS res- onators. The frequencies of the anti-phase (ωanti) and in-phase (ωin) modes have a strong dependency on the suspension and inner stiffness, respectively. Therefore the frequency difference can be electro- statically tuned by either suspension stiffness nor inner stiffness. The amplitude ratio can be adjusted largely by decreasing the inner stiffness, which brings a significant change in Q-factor related to anchor loss or squeeze film damping, while a negligible shift in frequency ωanti. When the frequency ωanti is tuned by decreasing suspension stiffness of two main proof masses, only a slight change in the mode shape, i.e. the amplitude ratio, is observed causing a minor adjustment to Q-factor. Therefore the frequency ωanti and Q-factor can be tuned independently under a little mutual influence.
A two-axis symmetric tuning fork resonator based on TMR technique is applied for QFM/RIG. Two dynamically equivalent proof masses provide a balance dynamic system and four extra-small masses is implemented in between them, which could tune the Q-factor of two anti-phase modes independently with small effect on the frequency. Frequency is mainly affected by suspension stiffness and Q-factor is strongly dependent on the squeeze film damping through the mode coupling between two balanced masses and small masses.
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