MEMS电化学角加速度传感器研究

近场强地震转动分量引起的扭转应力对建筑结构的破坏性更强，因此在强地震观测中角加速度的检测尤为重要。受到传统制造技术和敏感机理的限制，现有角加速度传感器的响应频带、动态范围、一致性等受到了制约，影响了其在强震观测中的应用。为此，本项目提出一种基于电化学敏感机理的新型角加速度传感器，利用MEMS技术设计制造平面超微电极和磁流体电极，实现电化学敏感电极参数的优化调整。项目拟通过建立与分析新型超微电极角加速度传感器敏感机理和噪声的数学模型，研究影响其灵敏度、动态范围、频带宽度、噪声水平、线性度等指标的重要影响参数；进一步探索并剖析敏感电极尺寸、微流道结构与传感器频率响应之间的内在联系和规律；并通过理论分析与实验验证，研究传感器基于磁流体动力学的力平衡负反馈的频带拓展方法。以期研制出超低频、高灵敏度的角加速度传感器，促进其在强地震转动分量测量中的应用。

Since buildings and other structures are generally vulnerable to torsional stresses resulting from rotational components of near-zone strong earthquakes, measurements of rotational motions （angular accelerations）are extremely valuable in earthquake monitoring. Due to limitations of conventional fabrication processes and sensing mechanisms, it is full of challenges to improve performances of the state-of-the-art angular acceleration sensors from the perspective of frequency response, dynamic range, conformity and robustness. In order to deal with this issue, a novel angular acceleration sensor based on electrochemical sensing mechanism is proposed in this project. MEMS technologies will be introduced for the design and fabrication of planar ultra-microelectrodes and magneto- hydrodynamic feedback electrodes, contributing to parameter optimization and performance improvement. Based on the development and analysis of corresponding sensing and noise mathematical models of the novel angular acceleration sensor with ultra-microelectrodes, the project is aimed to 1) study the influences of key parameters on device sensitivity, dynamic range, frequency bandwidth, noise level and linearity, and 2) explore and analyze the relationship among sizes of sensitive electrodes, structures of flow channels and device frequency responses. Through theoretical analysis and experimental validation, frequency band expansion methods based on force-balanced negative feedback of magnetohydrodynamics will be studied. It is expected to develop ultra low frequency, high sensitivity angular acceleration sensors and promote their applications in the measurement of rotational components of strong earthquakes.