针对厚度渐变高分子结构介电性能检测问题，设计一种变间距叉指型相邻电容传感器。研究不同叉指个数和极板覆盖率对等间距叉指相邻电容传感器信号强度和穿透深度的影响，确定了单对叉指单元的宽度范围|研究单对叉指单元参数对相邻电容传感器性能的影响，得到单对叉指单元传感器的穿透深度|根据待测结构厚度变化规律，对组成叉指传感器电极的单个叉指单元的宽度和间距进行了优化设计，设计出变间距叉指型相邻电容传感器。仿真和试验结果表明，变间距叉指型相邻电容传感器的信号强度和灵敏度优于等间距传感器，该传感器更适合渐变厚度结构材料的介电性能检测。
Aiming at the problem of dielectric property detection of polymer materials with thickness gradual changes structure, an improved interdigital capacitive proximity sensor is designed. Finite element simulation method is proposed to investigate the effects of different number of fingers and metallization ratio on the signal strength and penetration depth, and the scope of the single pair interdigital unit width is determined. The influence of different interdigital unit width and metallization ratio for the sensor performances are carried out, the penetration depth curves are acquired. Based on the structure characteristics of the materials under test, the width of each finger which composed the interdigital sensor electrodes is optimized individually. An improved interdigital capacitive proximity sensor is designed. The results of simulation and experimental indicate that the signal strength and sensitivity are better than the traditional interdigital sensors, thus the improved interdigital sensor is more suitable for the dielectric property detection of the gradual change thickness structure.
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