Artificial Spider Silk with Buckled Sheath by Nano-Pulley Combing.

Axial orientation of molecular chains always results in an increase in fibre 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 fibres through cyclic stretch-release training, which exhibits axial alignment of the polymer chains in fibre core and buckling in fibre 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 fibre materials. This article is protected by copyright. All rights reserved.