Transparent, mechanically robust, low-temperature-tolerant, and stretchable ionogels enhanced by konjac glucomannan toward wireless strain sensors

Electronic skins (E-skins) can detect human health and movement, and have potential in the fields of human–machine interactions and artificial intelligence. However, traditional hydrogel-based E-skins suffer from poor mechanical strength, low conductivity, and instability due to water evaporation. Herein, a semi-interpenetrating network developed by polysaccharide biomass konjac glucomannan (KGM) was introduced into a covalent-crosslinked network polyacrylamide-co- polyacrylic acid (PAM-co-PAA) to advance the above dissatisfaction of E-skins. This synthesized a transparent, tough, non-volatile, and highly stretchable ionogel with an ionic liquid named 1-ethyl-3-methylimidazolium dicyamide (EMIM:DCA) as conductive media. This ionogel exhibited extraordinary mechanical strength (tensile strength of 2.77 MPa), outstanding mechanical durability (100 stretching cycles of 250%), and elongation (elongation at break of 997%). More importantly, the ionogel demonstrated remarkable anti-freezing performance (high flexibility at -20℃) and high conductivity (3.94 mS/cm) in the absence of water. Besides, after assembling KGM-enhanced ionogel, the sensor exhibited comprehensive strain sensing performance, which could effectively and accurately monitor human motion via Bluetooth transmission. This strategy paves the way for a viable new generation of multifunctional biomimetic super-sensitive sensors, which are promising for applications such as intelligent devices, health detection, and biomedical monitoring in harsh conditions.