Double-network-inspired mechanical metamaterials

作者：J. U. Surjadi, Bastien F. G. Aymon, Molly Carton, Carlos M. Portela · 发表于：Nature Materials · 年份：2024 · DOI：10.1038/s41563-025-02219-5 · 被引用次数：111 · 研究领域：Physics、Medicine

Mechanical metamaterials can achieve high stiffness and strength at low densities, but often at the expense of low ductility and stretchability—a persistent trade-off in materials. In contrast, double-network hydrogels feature interpenetrating compliant and stiff polymer networks, and exhibit unprecedented combinations of high stiffness and stretchability, resulting in exceptional toughness. Here we present double-network-inspired metamaterials by integrating monolithic truss (stiff) and woven (compliant) components into a metamaterial architecture, which achieves a tenfold increase in stiffness and stretchability compared to its pure counterparts. Nonlinear computational mechanics models elucidate that enhanced energy dissipation in these double-network-inspired metamaterials stems from increased frictional dissipation due to entanglements between networks. Through introduction of internal defects, which typically degrade mechanical properties, we demonstrate a threefold increase in energy dissipation for these metamaterials via failure delocalization. This work opens avenues for developing metamaterials in a high-compliance regime inspired by polymer network topologies. Inspired by the entangled structure of double-network hydrogels, the authors integrate stiff truss and compliant woven components into metamaterial architectures to realize simultaneous high stiffness and high stretchability.