Highly stretchable, self-healable and wide temperature-tolerant deep eutectic solvent-based composite ionogels for skin-inspired strain sensors

The construction of ionogels with high stretchability, self-healability and wide-temperature tolerance is highly demanded. Here, an intrinsically stretchable deep eutectic solvent (DES)-based composite ionogel (DESCI) is prepared by in-situ polymerization of choline chloride/acrylic acid DES in the polyethylene glycol (PEG) matrix. The chemically crosslinking network among the resultant DESCI could serve as a strong crosslinking site to impart high mechanical strength and resilience, while the high-density hydrogen-bonded network with dynamic reversibility could provide excellent self-healability and ductility. The prepared DESCI with the hierarchically responsive networks thus exhibits a high stretchability of >700%, an ultimate tensile strength of ∼181 kPa, and a 24-h healing efficiency of 75% at room temperature. The as-prepared DESCI could act as a stretchable ionic conductor for wearable strain sensors in real-time sensing of complex motions. The wide-temperature tolerance and self-healing ability of DESCI effectively extend its lifetime for great potential in wearable electronics.