Double Network Glycerol Gel: A Robust,Highly Sensitive,and Adaptive Temperature Sensor

Temperature sensors have great potential applications for the body temperature monitoring, it's a big challenge to prepare sensors with high sensitivity and maintaining adaptive properties for the long-term applications. In this study, an organohydrogel for the temperature sensor is achieved via glycerol solvent replacement of water in the poly-N-acryloyl glycinamide (PNAGA)/carrageenans double network (DN) hydrogel. Owing to successful construction of strong multiple hydrogen bonding (H-bonding) interactions among PNAGA chains and carrageenans, the PNAGA-based glycerol gel (Gly-gel) sensor exhibits excellent thermal stabilities, possesses high sensitivities (2% °C) resulted from the acceleration of mobility of ions at high temperature and shows high tensile strength of about 4 MPa without chemical crosslinkers (higher than most reported organohydrogel-based temperature sensor) with self-healable performance. In addition, the double network of Gly-gel enables it excellent dual and triple shape memory performance with high fixing ratio (R_f, 88%), recovery ratio (R_r, 95%) under large deformations (above 80%) that are beneficial to the potential application in wearable devices. Different from previous temperature sensors, this work provides a facile approach to prepare overly sensitive temperature sensors with the combination of excellent thermal stability, high tensile strength and adaptive properties via the solvent replacement of hydrogel.