基于介观压阻效应的新型微陀螺仪结构设计与优化

Structure Design and Optimization of the Novel Micro-Gyroscope Based on Meso-Piezoresistive Effect

介绍了介观压阻效应,其灵敏度比硅压阻效应高一个数量级.利用该效应作为高灵敏度器件,首次提出了介观压阻效应微陀螺仪结构,并论述了其工作原理.利用AN SY S软件,对其结构性能进行仿真,分析了固有频率、振幅以及哥氏效应下敏感方向的位移等特性,提出了结构优化分析的方法.在哥氏效应等耦合作用下对该结构进行多参数优化设计,并得到优化结果.经过对结果进行比较和考量分析,结果证明:微陀螺仪的驱动频率和检测频率的差值由原来的217.83 H z增大到362.87 H z,微陀螺仪的工作带宽增大,同时质量块在Z方向的位移增大了0.3μm,从而使检测梁根部受到的应力也增大了1.7 M Pa,结构灵敏度提高了18%.

The meso-piezoresistive effect is presented and its sensitivity is one order higher than that of silicon piezoresistive effect. The micro-machined gyroscope based on mesopiezoresistive effect by using this effect as a high-sensitivity response is proposed for the first time and the operation principle of the gyroscope is also discussed. The structure performances are simulated by ANSYS software. The characteristics including natural frequency, amplitude and the sensitive displacement under the Coriolis effect are analyzed. The methods of structural optimization are also proposed. The optimized results are obtained by multi-parameters structure optimization methods at the role of Coriolis coupling effect. According to the comparison and analysis, it is proved that the operating bandwidth of the micromachined gyroscope increases as the difference between the drive frequency and the detect frequency increases from original 217.83 Hz to 362.87 Hz. At the same time, the displacement of the proof mass in Z direction increases by 0.3μm, so that the stress at the root of the detection beam also increases by 1.7 MPa and the structure-sensitivity increases by 18%.