基于阶梯分层式微结构的高性能柔性磁场传感器研究

High-performance flexible magnetic field sensor plays an important role in accurate position sensing of intelligent robots. Currently, flexible magnetic field sensors have achieved high sensitivity by using microstructure design, but the problem of linear working range is still outstanding, where the main reason is that single-type microstructure design limits its linear deformation range. In order to have flexible magnetic field sensors with both high sensitivity and wide linear working range, this project is proposed to compensate the equivalent spring constant of the sensing layer by designing a stepped hierarchical micropost array, thereby expanding the linear working range of the device, at the same time, maintaining high device sensitivity. Focus on: (1) Design method for expanding linear working range of the sensor based on stepped hierarchical microstructure; (2) Influence of sensing electrode design on magnetic field force transmission efficiency and device sensitivity; (3) Modeling of the high performance flexible magnetic field sensor and their array design. On the basis of theoretical model and simulation analysis, the flexible magnetic field sensor with high sensitivity and wide linear working range will be fabricated microfabrication technology combined with replica technology of flexible material. After that, large-scale lithography will be applied to fabricate sensor array. Results of the project will provide theoretical guidance and experimental basis for the fabrication of flexible magnetic field sensors, and ultimately, serve the high-precision position sensing requirements of intelligent robots.

高性能柔性磁场传感器对当前智能机器人实现精确位置传感发挥着重要作用。目前的柔性磁场传感器通过微结构的设计取得了优异的器件灵敏度，但线性工作范围的问题仍然突出，主要原因是单一微结构限制了自身线性形变范围。为了获得高灵敏度和大线性工作范围的柔性磁场传感器，本项目拟通过设计阶梯分层式的微柱阵列实现传感层等效弹性系数补偿，从而扩展器件的线性工作范围，同时保证器件具有高灵敏度。重点研究（1）扩大器件线性工作范围的阶梯分层式微结构的设计方法；（2）传感电极设计对磁场力传导效率和器件灵敏度的影响机理；（3）高性能柔性磁场传感器的模型化和阵列化。在理论模型和仿真分析的基础上，通过微加工技术与柔性材料的翻模技术相结合的方式制备具有高灵敏度和大线性工作范围的柔性磁场传感器，并结合大规模光刻技术实现传感器基元的阵列化。为柔性磁场传感器的制备提供理论指导和实验基础，并最终服务智能机器人的高精度位置传感需求。

柔性磁场传感器在智能机器人空间位置感知和非接触人机交互方面具有重要的作用。当前，多数研究主要围绕如何有效提升器件的灵敏度，然而，如何在保证高灵敏度的同时，拥有更大的响应范围和更宽的线性工作区间这一问题仍旧比较突出，一定程度上阻碍了柔性磁场传感器在实际场景中的大范围应用。针对上述问题，本项目开展了一系列研究工作。首先通过设计非均匀分布的微柱结构提升了器件的灵敏度；其次利用多层堆叠具有双面阶梯微结构薄膜的方式，大大提升了器件的响应范围和线性度；最后，构建并验证了基于磁压阻效应的磁场传感器理论模型，进而制备了结合阶梯微结构磁性基底与多层堆叠导电网络的柔性磁场传感器。该传感器具有高磁场响应灵敏度和宽工作范围，同时具有较好的线性度，能够满足机械手的空间位置与运动轨迹感知以及非接触的智能人机交互应用。. 综上所述，本项目为高性能柔性磁场传感器的研究提供了较好的理论依据和实验基础，保证传感器今后在智能机器人与人机交互等方面具有广阔的应用前景。