Xia Jie, Wang Xuepei, Wang Xiang, Majer-Baranyi Krisztina, Zhang Xiaoshuan
College of Engineering, China Agricultural University, Beijing 100083, China.
School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
ACS Omega. 2022 Apr 23;7(17):14994-15004. doi: 10.1021/acsomega.2c00743. eCollection 2022 May 3.
In recent years, advances in materials science and manufacturing technologies have facilitated the development of flexible sensors. However, there are still performance gaps between emerging flexible sensors and traditional silicon-based rigid sensors, especially lacking dynamic modeling and optimization analysis for addressing above challenges. This paper describes a hysteresis dynamic modeling method for flexible humidity sensors. Through inkjet printing and coating methods, the polyvinyl alcohol (PVA) sensitive layer and nano silver interdigital electrode are fabricated on flexible polyethylene naphthalate substrates. The performance characterization results show that the sensitivity and maximum hysteresis within the range of 12-98% relative humidity (RH) are -0.02167 MΩ/% RH and 2.7% RH, respectively. The sensor also has outstanding dynamic response ability and stability in a wide range of humidity variation. The hysteresis mechanism of flexible humidity sensors is theoretically analyzed from microscopic hysteresis processes, Langmuir monomolecular adsorption dynamic modeling, and Fick diffusion dynamic modeling. These hysteresis models provide a path for the hysteresis optimization of flexible PVA humidity sensors. Further exploration of the diffusion rate of water molecules and the proportion of PVA in ink represents promising hysteresis optimization directions of flexible humidity sensors based on PVA-sensitive material.
近年来，材料科学和制造技术的进步推动了柔性传感器的发展。然而，新兴的柔性传感器与传统的硅基刚性传感器之间仍存在性能差距，尤其是缺乏针对上述挑战的动态建模和优化分析。本文介绍了一种用于柔性湿度传感器的滞后动态建模方法。通过喷墨打印和涂覆方法，在柔性聚萘二甲酸乙二醇酯基板上制备了聚乙烯醇（PVA）敏感层和纳米银叉指电极。性能表征结果表明，在相对湿度（RH）为12 - 98%的范围内，灵敏度和最大滞后分别为-0.02167 MΩ/%RH和2.7%RH。该传感器在宽湿度变化范围内还具有出色的动态响应能力和稳定性。从微观滞后过程、朗缪尔单分子吸附动态建模和菲克扩散动态建模等方面对柔性湿度传感器的滞后机理进行了理论分析。这些滞后模型为柔性PVA湿度传感器的滞后优化提供了一条途径。进一步探索水分子的扩散速率和油墨中PVA的比例，是基于PVA敏感材料的柔性湿度传感器有前景的滞后优化方向。
