Engineering an Advanced Ionogel by Modulation the Solvent/Network Interactions: High Strength, Ultra-Stretchability,...

Ionogels have emerged as a pivotal material in the field of flexible electronics and wearable devices due to their excellent stretchability, ionic conductivity, and stimulus responsiveness. It remains challenging to integrate high mechanical strength, self-healing capability, and controllable adhesion into a single material system. To overcome this challenge, a fully physically crosslinked network was designed via in-situ photopolymerization of NIPAM in a water/[EMIM][DCA] binary solvent. Critically, water modulates system polarity, broadening the LCST to 47°C while enhancing dynamic hydrogen bonding and electrostatic interactions between imidazolium cations and dicyanamide anions. These reversible yet robust crosslinks efficiently dissipate mechanical energy, enabling the ionogel to achieve both high strength (0.32 MPa) and ultrahigh stretchability (1872%). The dynamic network also allows room-temperature self-healing with 98% stress recovery after 24 h. Above the LCST, thermally switchable adhesion is realized (643 kPa on copper), while ionic conductivity remains stable at 0.354 S/m. As a strain sensor, the gel exhibits high sensitivity (GF  =  2.09 at 400% strain) and excellent cycling stability for monitoring human motions. This work provides a binary solvent strategy that leverages polarity modulation and dynamic physical crosslinking to integrate multiple mechanical and functional properties into a single ionogel system.