Highly stretchable, anti-swelling, and strong adhesion fluorinated copolymer ionogel for flexible strain sensors and underwater communications

Ionogels have attracted great attention in flexible wearable devices due to their excellent deformability, high ionic conductivity and sensitive stimulus response. However, most of the reported ionogels still struggle to simultaneously achieve high stretchability, anti-swelling capability, temperature resistance, self-healing ability, and strong adhesion, especially in underwater or extreme environments. Herein, a highly stretchable, anti-swelling, and wide temperature-tolerant fluorinated copolymer ionogel is successfully prepared by photoinitiated copolymerization of fluorinated esters (HFBA) and acrylamide (AAm) monomers in hydrophobic ionic liquid (IL). The dynamic physical interactions of abundant hydrogen bonds and ion-dipole enabled the ionogel with highlighted self-healing and adhesion properties at different temperatures, as well as remarkable anti-swelling in water/organic solvents and wide temperature resistance (-53–230 ℃). In addition, the ionogel-based strain sensor exhibits high sensitivity, high stretchability, fast response, and excellent durability to precisely detect different activities in the human body. More importantly, the ionogel-based sensor can also be used as an underwater communication tool to efficiently transmit information by detecting the regular bending of the finger and relying on the Morse code principle, which provided an easy and effective method for the development of wearable underwater sensors and communication devices in the future.