Multifunctional Elastic Supramolecular Hydrogels with Self-Healing, Adhesive, and Ionic Thermoelectric Property for Flexible Sensing and Energy Harvesting

Supramolecular hydrogels capable of integrating mechanical robustness, strong adhesion, and reliable energy conversion remain highly sought for next-generation soft electronics. Here, we present a transparent, ultra-stretchable ionic hydrogel constructed through synergistic host–guest interaction, hydrogen bonding, and electrostatic interactions. The dynamic network exhibits outstanding mechanical performance (2173% strain, 340 kPa strength, 2.88 MJ m⁻³ toughness), rapid self-healing, broad-substrate adhesion, and potent antibacterial activity. The hydrogel functions as a sensitive strain sensor with stable, multimodal motion detection. It further serves as an efficient electrode for both triboelectric and droplet-based energy harvesting, powering commercial LEDs. Notably, the material exhibits a high p-type ionic thermoelectric response, achieving a Seebeck coefficient of 2.95 mV K⁻¹ and scalable thermovoltage output up to 14.3 mV/K in modular ionic thermoelectric capacitors. This work provides a versatile materials platform toward integrated soft electronics with simultaneous mechanical, sensing, and energy harvesting functionalities.