基于模态局部化的弱耦合谐振式惯性敏感机理及器件研究

This project proposes a new inertial transduction scheme based on mode localization of the weakly coupled resonators. Using this scheme, some high accuracy inertial sensors will be proposed and realized. A weakly coupled resonators system means that the stiffness of the coupling beam is much smaller than that of the resonant beams. When an external acceleration acts on the proof masses which connects to one of the resonators, the balance of the weakly coupled resonators is broken, which leads to a big change of the amplitude ratio. Therefore, the acceleration could be sensed by measuring the change of the amplitude ratio. The sensitivity based on the amplitude ratio measurement is 2~3 orders of magnitude higher than that of the traditional frequency sensing method. The fabrication process is completely compatible with the traditional MEMS process technology. It is a very promising method to realize the high accuracy micromachined inertial sensors.

本项目提出并研究一种基于模态局部化的高灵敏度、谐振式惯性敏感机理，并设计实现相应的高精度惯性传感器。其敏感机理是：两个弱耦合的微机械谐振器中的一个谐振器与惯性质量块相连接，当外界有惯性输入时，与惯性质量块相连的谐振器刚度发生微弱变化，该弱耦合谐振系统发生失调，模态局部化现象发生，此时两个谐振器的振幅比会发生明显变化，通过检测振幅比的变化就可以敏感惯性输入量的大小。相比于传统的基于频率变化的敏感机理，这种基于振幅比变化的敏感机理，灵敏度可提高2~3个数量级，且对温度、压力等环境变化不敏感。在工艺实现上，该敏感机理可完全基于传统MEMS工艺来实现，是一种非常有前景的高精度惯性传感器实现方法。

当前MEMS传感器的精度发展已经进入一个瓶颈期，迫切需要新方法或者新机理来突破MEMS传感器的精度极限。 本项目基于弱耦合谐振式的模态局部化现象，提出了一种新型的惯性敏感机理，建立了它的理论体系，设计了国际上首个基于模态局部化的MEMS加速度传感器，其分辨率达到了15.08ng/√Hz，在惯性导航、重力测量、电学检测等领域具有广阔的应用前景。