Tough and extreme temperature tolerant ionogel for highly sensitive sensor

Hydrogel skin-like sensors, widely applied in wearable electronics, have attracted considerable attention due to their feasibility, tissue-like compliance, and biocompatibility. However, freezing intolerance, moisture evaporation and less durability in the extreme environments would result in performance degradation (signal-sensing disturbance and low sensitivity). Herein, an ionogel with extreme temperature (-80℃-100℃) tolerance, fatigue durability was developed and exhibited high sensitivity in a wide working range (-30℃-80℃) as the temperature and strain sensor. The ionogel was prepared by a facile one-step polymerization method from a homogeneous pre-gel solution containing ionic liquid, monomers and crosslinkers. The tough ionogel exhibited high strength (1.25 MPa), mechanical enhancement (50 %) and good fatigue resistance (100 % strain for 1000 cycles). When assembled into the wearable strain and temperature sensor, it effectively detected various human motions through electrical signal outputs. Owing to the thermal stability of ionic liquid, the ionogel exhibited excellent long-term cyclic sensing performance. Furthermore, it exhibits high temperature sensitivity (TCR= −1.57 %/℃), freezing and thermal tolerance, meanwhile maintaining reliable sensing capability in the temperature range of −30℃-80℃. Thus, the ionogel could realize the wide temperature range detection in extreme environments, providing an innovative solution to the healthcare monitoring, artificial intelligence, and sensory devices.