电容式MEMS三维风速传感方法研究

As an innovative direction, MEMS 3D wind measurement has good prospects for application in various fields such as aerospace and industry. Therefore, a novel sensor with the sensing elements in the substrate is proposed to realize 3D wind detection. The differential capacitors and dual-layer capacitors are applied to obtain the wind information in horizontal and vertical direction, respectively. First, model including wind, force and electric is established to study the internal mechanism. Then, the sensor is fabricated by studying the mechanism of the sensitive material. Finally, the fabricated sensors are tested in 3D wind field to obtain the data. The scientific problems to be solved include: ① research on coupling behavior of the sensor in 3D wind sensor；② research on the stress and strain in the capacitors; ③ research on Young’s modulus of the functional mixture with different composition. Design theory and implementation method of the MEMS 3D wind sensor are expected. The development of the prototype can lay the foundation for the application of MEMS 3D wind sensor in future.

MEMS三维风速测量在航空航天和工业等领域有广泛应用前景，是风速传感器的前沿技术方向。本项目创新性地提出一种MEMS三维风速传感器，将敏感元件置于衬底内部，利用扭动差分电容结构和叠层电容结构分别实现水平方向和竖直方向的风速风向测量。首先建立风速传感器风-力-电转换模型，从理论上探明其内在作用机制；然后通过敏感材料构成机理的研究，实现风速传感器的制备；最后完成传感器在三维风场中的输出响应测试，获取准确实验数据。拟解决的科学问题为：① 三维风场中传感器的流固耦合行为研究；② 电容结构中的应力与应变分析；③ 功能性混合材料组成比例对其杨氏模量的影响。预期将解决MEMS三维风速传感器相关的设计理论和实现方法，研制出原型样机，为未来应用奠定基础。

相对于传统风速传感器，利用MEMS技术制备的风速传感器具有小型化、易集成、可批量生产等优点，在航天航空和工农业生产中具有广阔应用前景。.本项目研究了电容式MEMS三维风速传感器，利用平行板电容将待测量的风场信息转换为易于测量的电容信息。其中，风场大小由电容变化幅度表征，横向（x、y方向）探测有效量程为5-23.9m/s，最大电容变化幅度为0.058pF，纵向（z方向）探测有效量程为9.6-23.9m/s，最大电容变化幅度为0.041pF；风场方向由电容变化趋势表征，通过多个电容的组合分析即可完成对三维风向的测量。.在器件制备过程中发现，衬底（PDMS）制备参数直接影响器件结构的杨氏模量，一是PDMS基材与固化剂的混合比例，比例越高，杨氏模量越小，本项目取20:1；二是固化温度，温度越低，杨氏模量越小，本项目取90℃；三是固化时间，时间越短，杨氏模量越小，本项目取4h。通过改变PDMS制备参数，合理降低器件结构杨氏模量，进而提高传感器的灵敏度。