Rough Fibrils Provide a Toughening Mechanism in Biological Fibers
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- 作者：Cameron P. Brown ; Catalin Harnagea ; Harinderjit S. Gill ; Andrew J. Price ; Enrico Traversa ; Silvia Licoccia ; Federico Rosei
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：March 27, 2012
- 年：2012
- 卷：6
- 期：3
- 页码：1961-1969
- 全文大小：1102K
- 年卷期：v.6,no.3(March 27, 2012)
- ISSN：1936-086X
文摘
Spider silk is a fascinating natural composite material. Its combination of strength and toughness is unrivalled in nature, and as a result, it has gained considerable interest from the medical, physics, and materials communities. Most of this attention has focused on the one to tens of nanometer scale: predominantly the primary (peptide sequences) and secondary (尾 sheets, helices, and amorphous domains) structure, with some insights into tertiary structure (the arrangement of these secondary structures) to describe the origins of the mechanical and biological performance. Starting with spider silk, and relating our findings to collagen fibrils, we describe toughening mechanisms at the hundreds of nanometer scale, namely, the fibril morphology and its consequences for mechanical behavior and the dissipation of energy. Under normal conditions, this morphology creates a nonslip fibril kinematics, restricting shearing between fibrils, yet allowing controlled local slipping under high shear stress, dissipating energy without bulk fracturing. This mechanism provides a relatively simple target for biomimicry and, thus, can potentially be used to increase fracture resistance in synthetic materials.