Bio-Inspired Stretchable and Contractible Tough Fiber by the Hybridization of GO/MWNT/Polyurethane

Spider silks represent stretchable and contractible fibers with high toughness. Those tough fibers with stretchability and contractibility are attractive as energy absorption materials, and are needed for wearable applications, artificial muscles, and soft robotics. Although carbon-based materials and poly (vinyl alcohol) (PVA) composite fibers exhibit high toughness, it is still limited in low extensibility and inability to operate in the wet-state condition. Herein, we report stretchable and contractible fiber with toughness that is inspired by the structure of spider silk. The bio-inspired tough fiber provides 495 J/g of gravimetric toughness, which exceeds 165 J/g of spider silk. Besides, the tough fiber was reversibly stretched to ~80% strain without damage. This toughness and stretchability are realized by hybridization of aligned graphene oxide/multi-walled carbon nanotubes in a polyurethane matrix as elastic amorphous regions and β-sheet segments of spider silk. Interestingly, the bio-inspired tou...