Fabrication of Strong Tough Hydrogels Inspired by the Hydration-Flexibilization Process of Discinisca tenuis Shells

Hydrogels, known for their unique physical and chemical properties, hold significant potential for various applications. However, the inherent conflict between achieving both high strength and toughness often results in suboptimal mechanical performance, which significantly restricts their practical use. The shell of Discinisca tenuis is a layered natural biomaterial that exhibits high strength and toughness due to slight layer loosening during hydration, inspiring the design of tough hydrogels. Inspired by this biological process, this study developed a biomimetic layered hydrogel using a layered membrane hydration approach, optimizing the structural integrity through hot pressing to mimic the slight layer loosening observed in Discinisca tenuis shells after hydration, resulting in both high strength (55.26 MPa) and high toughness (21.04 MJ/m3). The research results indicate that slight layer loosening after hydration enables the biomimetic layered hydrogel to maintain high structural integrity, facilitating effective interlayer load transfer and achieving high strength, while also reducing spatial constraints, which improves ductility and results in high toughness. Additionally, the excellent energy dissipation capacity of the layered structure gives the hydrogel outstanding impact resistance, comparable to commercial materials like foamed polyethylene, silicone, and energy-absorbing rubber, indicating broad application prospects. In summary, this research proposes a general preparation strategy for tough hydrogels based on biomimetic principles, expected to advance the field of hydrogels.