Bioinspired nano-architecture for cellulose fibers with spider silk-like toughness.

Cellulose fibers derived from renewable biomass exhibit exceptional tensile strength through molecular alignment and dense packing, yet their toughness remains limited, typically below 50 MJ m-3. Drawing inspiration from the helical nanoarchitecture of cherry bark, we introduce a bioinspired nano-orientation strategy to fabricate regenerated cellulose fibers with a biaxially oriented structure via a scalable microfluidic spinning technique. Combining experimental characterization and molecular simulations, we demonstrate that this biaxial nano-architecture effectively redistributes stress and suppresses crack propagation during deformation, achieving a remarkable fracture strain of 41% alongside a tensile strength of 553 MPa. This synergy yields a toughness of 184 MJ m-3, exhibiting highly competitive performance relative to most previously reported cellulose fibers and synthetic polymers, and achieving a mechanical performance on the same order of magnitude as natural spider silk. Moreover, this enhancement extends seamlessly from single fibers to woven fabrics, highlighting its potential for sustainable, high-performance materials in textiles, automotive components, and aerospace applications. Our findings illuminate a design for overcoming the intrinsic brittleness of cellulose fibers, advancing their applicability as eco-friendly structural materials.