Temperature-Responsive Ionic Conductive Hydrogel for Strain and Temperature Sensors

作者：Qian Pang, Hongtao Hu, Haiqi Zhang, Bianbian Qiao, Lie Ma · 发表于：ACS Applied Materials & Interfaces · 年份：2022 · DOI：10.1021/acsami.2c06952 · 被引用次数：237 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Dielectric materials and actuators、Analytical Chemistry and Sensors

Flexible wearable devices have achieved remarkable applications in health monitoring because of the advantages of multisignal collecting and real-time wireless transmission of information. However, the integration of bulky sensing elements and rigid metal circuit components in traditional wearable devices may lead to a mechanical and signal-conducting mismatch between wearable devices and biological tissues, thus restricting their wide applications in the human body. The excellent mechanical properties, conductivity, and high tissue resemblance of conductive hydrogel contribute to its application in flexible electronic sensors to monitor human health. In this work, a dual-network, temperature-responsive ionic conductive hydrogel with excellent stretchability, fast temperature responsiveness, and good conductivity was developed by introducing a polyvinylpyrrolidone (PVP)/ tannic acid (TA)/ Fe 3+ cross-linked network into the N, N -methylene diacrylamide (MBAA) cross-linked poly( N -isopropylacrylamide- co -acrylamide) (P(NIPAAm- co -AM)) network. Furthermore, the introduction of the PVP/TA/Fe 3+ cross-linked network endowed the hydrogel with excellent stretchability and conductivity. By adjusting the molar ratio of TA and Fe 3+ to 3:5, a hydrogel with a maximal stretching ratio of 720% and sensitive strain response (GF = 3.61) was achieved, showing a promising application in wearable strain sensors to monitor both large and fine human motions. Moreover, by introducing PNIPAAm ...