Mode-Localized Z-Axis Accelerometer

Exploring the integration of in-plane and out-of-plane accelerometers is a significant research focus, with a primary challenge lying in the development of a precise Z -axis accelerometer. Although mode localization has been successfully applied to in-plane accelerometers, its application to Z -axis accelerometers remains challenging. This article presents the innovative design of a mode-localized Z -axis accelerometer based on a weakly coupled resonator (WCR) system. A seesaw structure is employed to translate the tested Z -axis acceleration into variations in the capacitor overlap area, inducing stiffness change of one resonator. The mode-localization phenomenon is triggered and the Z -axis acceleration can be determined through the amplitude of two resonators. The specifications of the Z -axis accelerometer are impressive, with a sensitivity of 9.48/g, noise floor of 6.03~μ g / Hz, and bias instability of 10.03~μ g. This article presents a new method for measuring out-of-plane acceleration and has the potential to be integrated with in-plane mode-localized accelerometers.