Catechol-Functionalized Poly(ionic liquid)-Based Self-Healing Adhesive Hydrogel for Repairable Wearable Sensor and Self-Powered System.

Conductive hydrogels have risen as a promising material for flexible wearable sensors. However, achieving a hydrogel that simultaneously possesses high mechanical properties, conductivity, self-healing ability, and adhesion remains a challenge. Herein, we developed a dual-network ionic conductive hydrogel (P-P(C-A)-PA) by incorporating poly(vinyl alcohol) and a copolymer of catechol-modified ionic liquid and acrylamide. The optimized hydrogel exhibited outstanding mechanical performance (stress: 883 kPa, strain: 1120%), self-healing efficiency (stress recovery of 58.6% ± 4.6% and toughness recovery of 57.7% ± 5.5%), ionic conductivity (3.91 S/m), and adhesion strength (50 kPa on Ecoflex). The hydrogel-based flexible sensor reliably monitored human motion with rapid and accurate signal response even after self-healing. The hydrogel-based triboelectric nanogenerator showed excellent output performance (180 V, 7.9 μA, and 65 nC), further identifying grasped objects and monitoring finger rehabilitation before and after self-healing. These results highlighted the considerable potential of our hydrogel for applications in advanced electronics.