pp 1–16 | Cite as

Nanofibrils as Building Blocks of Silk Fibers: Critical Review of the Experimental Evidence

  • Qijue Wang
  • Hannes C. SchnieppEmail author
Protein-Based Structural Materials


Silks have fascinated researchers for decades, featuring outstanding mechanical performance and vast potential as a multifunctional material. Development of synthetic fibers mimicking natural silk is a major goal but has been hindered by insufficient knowledge of the silk structure. Nanoscale fibrils have long been suggested to play a significant role in silk; in this review, we examine prior evidence of nanofibrils in spider and silkworm silks. We found the available data far from conclusive. The volumetric percentage of nanofibrils in silk fibers is totally unclear, and conflicting results have been reported regarding their physical dimensions, morphology, and spatial organization. Some works have proposed an entirely different, globular nanostructure of silk fibers. Hence, many of the structural models were developed based on incomplete evidence. Our review highlights the gaps in knowledge about the nanostructure of silk fibers and can act as a guide for future studies.



This material is based upon work supported by the National Science Foundation under Grant No. DMR-1352542.


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© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  1. 1.Applied Science DepartmentWilliam & MaryWilliamsburgUSA

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