Advanced Fiber Materials, 2019, vol 1, 3, pp. 231-240
Ductile and damage-tolerant fibers (DDTFs) are desired in aerospace engineering, mechanical engineering, and biomedical engineering because of their ability to prevent the catastrophic sudden structural/mechanical failure. However, in practice, design and fabrication of DDTFs remain a major challenge due to finite fiber size and limited processing techniques. In this regard, animal silks can provide inspirations. They are hierarchically structured protein fibers with an elegant trade-off of mechanical strength, extensibility and damage tolerance, making them one of the toughest materials known. In this article, we confirmed that nanofibril organization could improve the ductility and damage-tolerance of silk fibers through restricted fibril shearing, controlled slippage and cleavage. Inspired by these strategies, we further established a rational strategy to produce polyamide DDTFs by combining electrospinning and yarn-spinning techniques. The resultant polymeric DDTFs show a silk-like fracture resistance behavior, indicating potential applications in smart textile, biomedicine, and mechanical engineering.