Highly compressible ionic hydrogels with conductivity and self-healing capabilities using UV-curable silk sericin

Silk sericin (SS) hydrogels are attractive for soft-matter applications due to their natural origin, ease of processing, and superior hydrophilicity, yet their poor compressibility and structural stability remain key limitations. Here, we report a facile and scalable route for producing highly compressible ionic hydrogels by covalently grafting glycidyl methacrylate (GMA) onto SS (SS-g-GMA). The grafting density can be tuned between 81.26 % and 98.86 % simply by adjusting temperature and GMA dosage, yielding a UV-curable precursor that maintains excellent rheological properties. Photopolymerization generates a uniform, interconnected microporous network with pore sizes of average 27.24 μm pores, which imparts the hydrogel with an exceptional compressive stress of 70.03 kPa at 67.09 % strain and an ionic conductivity of 0.15 S m −1 . The recombination of hydrogen bonds facilitates rapid electrical self-healing (93.21 % recovery within 15 s). The stress-dependent resistance changes exhibit linear characteristics, rendering this compressible ionic hydrogel suitable for applications in stretchable electronics, biomedical scaffolds, and soft actuators.