该文揭示了一种动热源摆式单轴微机电系统(MEMS)热加速度计的敏感机理。在给出敏感结构原理的基础上, 通过建立二维物理研究模型、划分网格、加载加速度等方法对敏感结构内的温度场进行了计算。结果表明, 开机1.8 s后在敏感结构内形成了一个稳定的以动热源为中心的温度场; 输入加速度a时, 动热源沿着加速度方向偏移, 温度场随之偏移, 敏感轴方向上对称设置的两个热线温差ΔTX随着输入加速度a的加大而呈线性增长, 温度灵敏度为7.1×10-2 mK/g。根据输入-输出(a-VXOUT)特性曲线给出数学模型, 得到该加速度计灵敏度为0.5 V/g, 非线性度为2.8%, 从而揭示了敏感机理。

The sensing mechanism of a dynamic thermal source pendulum single-axis MEMS thermal accelerometer was revealed in this paper. Based on the principle of the sensitive structure, the temperature field inside the sensitive structure is calculated by establishing the two-dimensional physical research model, meshing the grid, loading the acceleration and other methods. The results show that a stable temperature field centered at the dynamic heat source is formed within the sensitive structure after 1.8 s of power-on. When inputting the acceleration a, the dynamic heat source shifts along the direction of acceleration, then the temperature field is shifted. The temperature difference ΔTX between the two hot lines symmetrically set in the direction of sensitive axis increases linearly with the increase of input acceleration a, and the temperature sensitivity is 7.1×10-2 mK/g. According to the input-output characteristic a-VXOUT curve, the mathematical model is given, and the sensitivity of accelerometer is 0.5 V/g, and the nonlinearity is 2.8%, which reveals the sensing mechanism.