面向输出性能的微加速度计建模与拓扑优化

Modeling and Topology Optimization of MEMS Accelerometer Oriented to Output Performance

摘要:

以MEMS(micro electro mechanical systems)技术制备的电容式微加速度计为研究对象，建立了其最终输出性能——检测电容的检测特性与其微结构之间的动力学模型，提出了微加速度计最终输出性能的计算方法，实现了面向微加速度计最终输出性能的动力学特性与检测特性分析.为提高微加速度计的输出性能，进行了微加速度计的结构拓扑优化.在考虑提高电容输出性能和模态约束的条件下，建立了微加速度计结构的拓扑优化流程与数学模型，并以优化算例说明方法的有效性.拓扑优化结果表明，优化后微加速度计的输出性能和灵敏度提高了4.92%，同时抑制了振动模态耦合，保持品质因子不变.

Abstract:

This work focuses on a capacitive micro accelerometer fabricated by micro electro mechanical systems MEMS technology, and the dynamics model between the detection characteristics of output performance (detection capacitance) and the microstructure is proposed. The calculation method of output performance of the accelerometer is presented. The analysis of the dynamics and detection characteristics of the accelerometer is achieved. To increase the output performance of the accelerometer, a structural topology optimization for the accelerometer is performed. The flow and mathematical model of the topology optimization for the accelerometer is built. A numerical example is presented to show the effectiveness of the method. The topology optimization results show that the output performance and sensitivity increase by 4.92%. The coupling of vibration modes is avoided and the quality factor is kept unchanged.