Enhancing sensitivity in mode-localized tilt sensors based on asymmetrically coupled resonators

Abstract Mode-localized tilt sensors with amplitude ratio (AR) outputs have been proven to have a significant improvement in sensitivity over conventional frequency outputs, and the coupling stiffness between the coupled resonators is the key to sensitivity. The resonators in tilt sensors are designed identically to form coupling and have an equivalent response to the external perturbation. This paper proposes a new method to improve the sensitivity without weakening the coupling stiffness between resonators by exploiting the asymmetry of coupled resonators. Using the amplitude ratio of the asymmetrically resonators with a smaller effective mass to the resonator with a larger effective mass as the output, the sensitivity of the mode-localized tilt sensor will be increased approximately by a factor of the ratio of the effective masses of the two resonators compared to symmetrically coupled resonators. Sensitivity can be increased to twice the original using asymmetrically coupled resonators, which has been verified both in theoretical analysis and finite element method (FEM) simulation.