基于半导电复合材料线圈的间隙压力传感器研究

To overcome the limitation that the pressure sensor based on semi-conductive composite cannot measure the non-contact gap, the traditional sheet shape of the composite is changed into a spiral shape to form a composite coil with the ability to induce the eddy current effect. The impedance of the composite coil can be changed with the non-contact gap. The contents include: to design the composite coil; to research the gap/pressure-impedance properties; to explore the mechanisms of the gap/pressure-impedance effects and establish the mathematical models; to develop the gap and pressure sensor system.. The spiral shape of the composite brings the novelties in the properties, the mechanisms and the applications. The innovation points include: the composite coil possesses the gap-impedance property which the composite with the traditional sheet shape does not possess; the eddy current effect of the composite coil is based on the tunneling current, which is different from the eddy current effect of the metal coil based on the movements of the free electrons; the composite coil possesses the ability to measure not only the pressure but also the gap.. The theoretical meanings lie in the facts that the achievements can offer the theoretical and experimental bases for the research on the gap/pressure-impedance effects of the composite coil, and “the exploration for the relation between the tunneling effect and the eddy current effect” can also provide a chance to find new rules in the field of electromagnetic induction; The applied values lie in the facts that the composite coil can be used in the industrial and civil fields, such as the gap/pressure measurements in the interlayer structure with small space and the electronic skin development, and the idea that “the shape of the composite is designed to be spiral” can also be extended to other kinds of pressure sensitive materials.

为克服基于半导电复合材料的压力传感器无法测量非接触式间隙的局限，本项目将复合材料的传统片状结构改为螺旋形，以形成能产生电涡流效应的复合材料线圈，其阻抗可随间隙变化。内容包括：设计复合材料线圈；研究间隙/压力-阻抗特性；探索间隙/压力-阻抗效应机理并建立数学模型；研制间隙压力传感系统。.由“复合材料的螺旋形”所带来的特性、机理和应用方面的创新点包括：间隙-阻抗特性是传统片状复合材料没有的；与基于自由电子运动的金属线圈电涡流效应不同，复合材料线圈电涡流效应是基于隧道电流的；兼具压力间隙测量能力。.理论意义在于：为复合材料线圈间隙/压力-阻抗效应研究提供理论与实验基础，“探索隧道效应和电涡流效应的联系”还将为在电磁感应领域发现新规律提供契机；应用价值在于：复合材料线圈可用于狭小层间间隙/压力测量和电子皮肤研制等工业和民用领域，“将复合材料设计为螺旋形”的思路还可推广到其它种类的压敏材料中。

为解决现有柔性压力传感器无法测量非接触式间隙的局限，本项目将具有本征柔性的半导电复合材料的传统片状结构改变为线圈式结构（即：复合材料线圈），通过其电涡流效应和压力-阻抗效应实现非接触式间隙测量和静态压力测量。主要成果包括：得到了一套成熟的制备工艺流程，制备出了复合材料线圈试样，并掌握了复合材料线圈的间隙/静态压力-阻抗特性与机理，进而研制了间隙/静态压力传感器系统。实验结果表明：接触阶段的静态压力-阻抗特性重复性和非接触阶段的间隙-阻抗特性随着载荷循环的增加而逐渐提高；定量获取了导电相含量与形貌等因素对静态压力-阻抗特性和间隙-阻抗特性的影响规律；以电涡流效应理论、有效导电通道理论和隧道效应理论为基础，揭示了复合材料线圈提离效应和静态压力-阻抗效应机理。以上述研究成果为依据，优化了复合材料线圈配比，改进了复合材料线圈制备方法、完善了封装工艺；得到了受力阶段判断方法、静态压力/间隙传感标定和转换方法、临界阻抗漂移判断方法和传感标定曲线修正方法；设计了压力/间隙-阻抗转换、交-直转换和模-数转换等环节，进而研制了信号处理系统，实现了狭小曲面层间非接触式间隙与静态压力测量。系统测试表明：非接触阶段的间隙测量偏差在0-0.2mm的量程内小于1%F.S.；接触阶段的静态压力测量偏差在0-0.2MPa量程内小于5%F.S.。本项目的成果可为复合材料线圈间隙/压力-阻抗效应研究奠定理论与实验基础，还可为工业设备狭小曲面层间静态压力和间隙测量提供技术指导，其关键技术还可用于人工电子皮肤研制等工业和民用领域。