State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , China.
School of Mechanical and Aerospace Engineering , Nanyang Technological University , Singapore 639798 , Singapore.
ACS Appl Mater Interfaces. 2018 Jun 6;10(22):19097-19105. doi: 10.1021/acsami.8b03524. Epub 2018 May 25.
An ultrastretchable thermistor that combines intrinsic stretchability, thermal sensitivity, transparency, and self-healing capability is fabricated. It is found the polyacrylamide/carrageenan double network (DN) hydrogel is highly sensitive to temperature and therefore can be exploited as a novel channel material for a thermistor. This thermistor can be stretched from 0 to 330% strain with the sensitivity as high as 2.6%/°C at extreme 200% strain. Noticeably, the mechanical, electrical, and thermal sensing properties of the DN hydrogel can be self-healed, analogous to the self-healing capability of human skin. The large mechanical deformations, such as flexion and twist with large angles, do not affect the thermal sensitivity. Good flexibility enables the thermistor to be attached on nonplanar curvilinear surfaces for practical temperature detection. Remarkably, the thermal sensitivity can be improved by introducing mechanical strain, making the sensitivity programmable. This thermistor with tunable sensitivity is advantageous over traditional rigid thermistors that lack flexibility in adjusting their sensitivity. In addition to superior sensitivity and stretchability compared with traditional thermistors, this DN hydrogel-based thermistor provides additional advantages of good transparency and self-healing ability, enabling it to be potentially integrated in soft robots to grasp real world information for guiding their actions.
一种兼具本征可拉伸性、热敏感性、透明度和自修复能力的热敏电阻被制备出来。研究发现，聚丙烯酰胺/卡拉胶双重网络（DN）水凝胶对温度非常敏感，因此可以被开发为热敏电阻的新型通道材料。这种热敏电阻在 200%的极限应变下，可从 0 拉伸至 330%，灵敏度高达 2.6%/°C。值得注意的是，DN 水凝胶的机械、电气和热传感性能可实现自修复，类似于人类皮肤的自修复能力。即使经历大角度的弯曲和扭转等大机械变形，其热敏感性也不会受到影响。良好的柔韧性使热敏电阻能够附着在非平面曲面上，用于实际温度检测。引人注目的是，通过引入机械应变可以提高热敏电阻的热敏感性，使其具有可编程的灵敏度。与传统的缺乏调节灵敏度的刚性热敏电阻相比，这种具有可调灵敏度的热敏电阻具有优势。与传统热敏电阻相比，这种基于 DN 水凝胶的热敏电阻不仅具有更高的灵敏度和可拉伸性，还具有良好的透明度和自修复能力，有望集成到软体机器人中，以获取真实世界的信息来指导其行动。
