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

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.