Measurement and Sensor Technology, Chemnitz University of Technology, 09126 Chemnitz, Germany.
Sensors (Basel). 2022 Aug 30;22(17):6530. doi: 10.3390/s22176530.
One of the main challenges during the integration of a carbon/polymer-based nanocomposite sensor on textile substrates is the fabrication of a homogeneous surface of the nanocomposite-based thin films, which play a major role in the reproducibility of the sensor. Characterizations are therefore required in every fabrication step to control the quality of the material preparation, deposition, and curing. As a result, microcharacterization methods are more suitable for laboratory investigations, and electrical methods can be easily implemented for in situ characterization within the manufacturing process. In this paper, several textile-based pressure sensors are fabricated at an optimized concentration of 0.3 wt.% of multiwalledcarbon nanotubes (MWCNTs) composite material in PDMS. We propose to use impedance spectroscopy for the characterization of both of the resistive behavior and capacitive behavior of the sensor at several frequencies and under different loads from 50 g to 500 g. The impedance spectra are fitted to a model composed of a resistance in series with a parallel combination of resistance and a constant phase element (CPE). The results show that the printing parameters strongly influence the impedance behavior under different loads. The deviation of the model parameter α of the from the value 1 is strongly dependent on the nonhomogeneity of the sensor. Based on an impedance spectrum measurement followed by parameter extraction, the parameter α can be determined to realize a novel method for homogeneity characterization and in-line quality control of textile-integrated wearable sensors during the manufacturing process.
在将基于碳/聚合物的纳米复合材料传感器集成到纺织基底上时，主要面临的挑战之一是制造基于纳米复合材料的薄膜的均匀表面，这在传感器的可重复性方面起着重要作用。因此，在每个制造步骤中都需要进行特性分析，以控制材料制备、沉积和固化的质量。因此，微观特性分析方法更适合实验室研究，而电特性分析方法可以很容易地在制造过程中进行原位特性分析。在本文中，我们在 PDMS 中优化了浓度为 0.3wt.%的多壁碳纳米管（MWCNT）复合材料，制备了几种基于纺织的压力传感器。我们建议使用阻抗谱来表征传感器在不同频率和不同负载（从 50g 到 500g）下的电阻行为和电容行为。阻抗谱拟合到一个模型，该模型由串联电阻和并联电阻与常数相位元件（CPE）的组合组成。结果表明，印刷参数对不同负载下的阻抗行为有很大影响。与值 1 的偏差的模型参数α强烈依赖于传感器的非均质性。基于阻抗谱测量和参数提取，确定参数α可以实现一种新的方法，用于在制造过程中对纺织集成可穿戴传感器的均匀性进行特性分析和在线质量控制。
