基于Fabry-Perot腔的高精度MEMS加速度传感器

High-Precision MEMS Acceleration Sensor Based on Fabry-Perot Cavity

设计了一种基于Fabry-Perot腔的高精度MEMS加速度传感器,采用动态波长调谐原理。加速度传感单元由二氧化硅支撑梁与中心质量块组成,在质量块底部与衬底层硅基凹槽内,利用薄膜沉积技术制备分布式布拉格反射镜(DBR)构成F-P光学微腔。设计了新型折叠支撑梁和维持器件可靠性的限位块结构。研究给出质量块位移引起腔长变化,导致透射波长偏移的关系,结合S型支撑梁挠曲度与系统加速度的关系,得到加速度与透射波长的函数,其线性度大于99.99%。通过有限元仿真软件对结构参数进行设计与优化,由仿真结果得出设计的加速度传感器工作频率为510 Hz,测量范围为±5 g,得到加速度-波长灵敏度为54.8 nm/g,最高分辨率可达1 mg设计可应用于自主导航、重力测量与资源勘探等。

A high-precision MEMS acceleration sensor based on the Fabry-Perot cavity is designed, which uses the principle of dynamic wavelength tuning.The acceleration sensing unit consists of a silicon dioxide support beam and a central mass.In the bottom of the mass and the silicon-based groove of the substrate layer, a distributed Bragg reflector(DBR) is prepared by thin film deposition technology to form an F-P optical microcavity.We designed a new type of folding support beam and a limit block structure to maintain device reliability.The study gives the relationship between the cavity length change caused by the displacement of the mass and the transmission wavelength shift.Combining the relationship between the deflection of the S-shaped support beam and the system acceleration, the function of acceleration and transmission wavelength is obtained, and its linearity is greater than 99.99%.The structural parameters are designed and optimized by finite element simulation software.The simulation results show that the designed acceleration sensor has an operating frequency of 510 Hz, a measurement range of±5 g, and an acceleration-wavelength sensitivity of 54.8 nm/g, with a maximum resolution of 1 mg.The design can be used in autonomous navigation, gravity measurement, and resource exploration.