Design And Simulation Of Nano Piezoelectric Beam Resonant Accelerometer

Micromachined resonant accelerometer based on MEMS technology has been strategically applied in inertial navigation and guidance.It can convert the acceleration signal into frequency change directly.The output accuracy and reliability can be improved by simplifying the digital circuit and eliminating the interference of the analog signal.However,the performance of the existing resonant accelerometers has now limited their extensive applications in inertial navigation and guidance,especially in high-precision guidance and attitude fine-tuning.Therefore,there is an urgent need in the development of high-precision resonant accelerometer.In recent years,novel nanomaterials have begun to be used in MEMS accelerometers.Therein,zinc oxide has high resonance frequency and excellent piezoelectric properties.Therefore,the resonant accelerometer based on the nano piezoelectric beam is expected to be used in the new generation of high-precision navigation and guidance.Based on the research status of resonant accelerometers and the high-precision applications,a resonant accelerometer based on nano-piezoelectric beams is designed.The zinc oxide is utilized as the resonator material,which significantly improves the resonant frequency,sensitivity,and frequency response of the resonator.The symmetrical distribution structure is designed for differential detection,resulting in the high sensitivity,and reducing the temperature common mode and nonlinear errors.The supporting beams are used to decrease the cross sensitivity and enhance the anti-interference ability.The physical models of the accelerometer and resonant beams are established,and the structural parameters of the nano-piezoelectric resonant accelerometer are optimized.First,the ANSYS Workbench simulation platform is applied to analyze the properties of the proposed accelerometer,resulting in the resonant frequencies of 2.98793 MHz and 2.98729 MHz for upper and lower resonators respectively.With these resonant frequencies,the displacement in X direction is two orders of magnitude higher than its in Y and Z directions.Then a maximum stress of the proposed accelerometer is calculated as 241.46 MPa under an acceleration load of 2000 g,which is far less than the ultimate strength of silicon and zinc oxide materials,indicating its capability of resisting the high overload.Within the acceleration range of ±10g,the sensitivity of this structure is 1.13311 k Hz/g.Finally,the fabrication process flow of the nano-piezoelectric resonant accelerometer was designed based on the SOI micromachining technology.