Artificial Spider Silk with Buckled Sheath by Nano-Pulley Combing

Abstract

The axial orientation of molecular chains always results in an increase in fiber strength and a decrease in toughness. Here, taking inspiration from the skin structure, artificial spider silk with a buckled sheath–core structure is developed, with mechanical strength and toughness reaching 1.61 GPa and 466 MJ m−3, respectively, exceeding those of Caerostris darwini silk. The buckled structure is achieved by nano-pulley combing of polyrotaxane hydrogel fibers through cyclic stretch–release training, which exhibits axial alignment of the polymer chains in the fiber core and buckling in the fiber sheath. The artificial spider silk also exhibits excellent supercontraction behavior, achieving a work capacity of 1.89 kJ kg−1, and an actuation stroke of 82%. This work provides a new strategy for designing high-performance and intelligent fiber materials.