Low hysteresis, anti-freezing and conductive organohydrogel prepared by thiol-ene click chemistry for human-machine interaction

Hydrogels are arousing increasing research interesting due to their potential application in the fields of motion detection and human-machine interaction. But the problems of high hysteresis, difficulty in preservation, and inadaptability to extreme conditions are still challenges nowadays. Herein, a multi-crosslinked PVA/EG/CNT-OH click-organohydrogel was prepared by photoinitiated thiol-ene click chemistry. Due to the presence of strong C–S bonds obtained by click chemistry, the click-gel has a dense structure with very low hysteresis at tensile strains of 200% and compressive strains of 50%, exhibiting a minimum dissipation energy of 0.0046 MJ m−3 and 0.00089 MJ m−3, respectively. On account of the synergistic effect of various crosslinks, it also has a tensile strength of 206 kPa, elongation at break of 408%, and compressive strength of 576 kPa at 80% compressive strain. Therefore, the click-gel has high fidelity for high-frequency motion detection as well as excellent self-recovery and anti-fatigue performances under a wide range of strain and pressure. Furthermore, the outstanding anti-freezing and moisture retention performance allow it to adapt to extreme environments. The click-gel paves a way for the development of sensors that can be used not only for human motions detection, but also as input devices of intelligent machine recognition systems for human-machine interaction.