Anisotropic nanomechanical properties of Nephila clavipes dragline silk

Spider silk is a material with unique mechanical properties under tension. In this study, we explore the anisotropic mechanical properties of spider silk using instrumented indentation. Both quasistatic indentation and dynamic stiffness imaging techniques were used to measure the mechanical properties in transverse and longitudinal sections of silk fibers. Quasistatic indentation yielded moduli of 10 ± 2 GPa in transverse sections and moduli of 6.4 ± 0.5 GPa in longitudinal sections, demonstrating mechanical anisotropy in the fiber. This result was supported by dynamic stiffness imaging, which also showed the average reduced modulus measured in the transverse section to be slightly higher than that of the longitudinal section. Stiffness imaging further revealed an oriented microstructure in the fiber, showing microfibrils aligned with the drawing axis of the fiber. No spatial distribution of modulus across the silk sections was observed by either quasistatic or stiffness imaging mechanics.

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Nephila clavipes Flagelliform Silk-Like GGX Motifs Contribute to Extensibility and Spacer Motifs Contribute to Strength in Synthetic Spider Silk Fibers

Biomacromolecules ◽

10.1021/bm400125w ◽

2013 ◽

Vol 14 (6) ◽

pp. 1751-1760 ◽

Cited By ~ 44

Author(s):

Sherry L. Adrianos ◽

Florence Teulé ◽

Michael B. Hinman ◽

Justin A. Jones ◽

Warner S. Weber ◽

...

Keyword(s):

Spider Silk ◽

Nephila Clavipes ◽

Silk Fibers

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A Structural Basis for Anisotropy in Cardiac Fibroblast Populated Collagen Gels

Advances in Bioengineering ◽

10.1115/imece2004-61209 ◽

2004 ◽

Author(s):

Stavros Thomopoulos ◽

Jeffrey W. Holmes

Keyword(s):

Myocardial Infarction ◽

Mechanical Properties ◽

Collagen Fiber ◽

Collagen Gel ◽

Mechanical Anisotropy ◽

Control Individual ◽

Structural Basis ◽

Collagen Gels ◽

Specific Loading ◽

Anisotropic Mechanical Properties

The development of anisotropic mechanical properties is critical for the successful function of many soft tissues. Load bearing tissues naturally develop varying degrees of anisotropy, presumably in response to their specific loading environment. For example, the scar tissue that forms after a myocardial infarction is structurally and mechanically anisotropic. To better understand the scar mechanics, we first need to develop structure-function relationships for collagen fiber networks. In order to improve the healing after myocardial infarction, a better understanding of the mechanical anisotropy is necessary. An in vitro collagen gel system can be used to control individual fiber network components and to determine the effect of each component on the mechanical properties of the gel. Previously, we demonstrated the ability to promote two different collagen gel structures, with two different levels of mechanical anisotropy [1]. The goal of the current study was to quantitatively relate the observed mechanical anisotropy to the collagen fiber structure. It was hypothesized that the anisotropy could be explained with a simple structural model, where the gel behavior is derived from the behavior of the individual fibers within the gel (i.e., the properties of the fibers, their orientation, and their level of slack).

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Mechanical properties and application analysis of spider silk bionic material

e-Polymers ◽

10.1515/epoly-2020-0049 ◽

2020 ◽

Vol 20 (1) ◽

pp. 443-457

Author(s):

Yunqing Gu ◽

Lingzhi Yu ◽

Jiegang Mou ◽

Denghao Wu ◽

Peijian Zhou ◽

...

Keyword(s):

Mechanical Properties ◽

Spider Silk ◽

Superior Performance ◽

Biomimetic Materials ◽

Silk Fibers ◽

Practical Applications ◽

Spider Web ◽

Potential Applications ◽

And Performance ◽

Fiber Materials

AbstractSpider silk is a kind of natural biomaterial with superior performance. Its mechanical properties and biocompatibility are incomparable with those of other natural and artificial materials. This article first summarizes the structure and the characteristics of natural spider silk. It shows the great research value of spider silk and spider silk bionic materials. Then, the development status of spider silk bionic materials is reviewed from the perspectives of material mechanical properties and application. The part of the material characteristics mainly describes the biocomposites based on spider silk proteins and spider silk fibers, nanomaterials and man-made fiber materials based on spider silk and spider-web structures. The principles and characteristics of new materials and their potential applications in the future are described. In addition, from the perspective of practical applications, the latest application of spider silk biomimetic materials in the fields of medicine, textiles, and sensors is reviewed, and the inspiration, feasibility, and performance of finished products are briefly introduced and analyzed. Finally, the research directions and future development trends of spider silk biomimetic materials are prospected.

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Relationship between microstructure and mechanical properties in spider silk fibers: identification of two regimes in the microstructural changes

Soft Matter ◽

10.1039/c2sm25446h ◽

2012 ◽

Vol 8 (22) ◽

pp. 6015 ◽

Cited By ~ 61

Author(s):

Gustavo R. Plaza ◽

José Pérez-Rigueiro ◽

Christian Riekel ◽

G. Belén Perea ◽

Fernando Agulló-Rueda ◽

...

Keyword(s):

Mechanical Properties ◽

Spider Silk ◽

Microstructural Changes ◽

Silk Fibers ◽

Microstructure And Mechanical Properties

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Basic Principles in the Design of Spider Silk Fibers

Molecules ◽

10.3390/molecules26061794 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1794

Author(s):

José Pérez-Rigueiro ◽

Manuel Elices ◽

Gustavo R. Plaza ◽

Gustavo V. Guinea

Keyword(s):

Mechanical Properties ◽

High Performance ◽

Spider Silk ◽

Design Principles ◽

Tensile Behavior ◽

Original Design ◽

Basic Principles ◽

Silk Fibers ◽

The Relationship ◽

Selection Of

The prominence of spider silk as a hallmark in biomimetics relies not only on its unrivalled mechanical properties, but also on how these properties are the result of a set of original design principles. In this sense, the study of spider silk summarizes most of the main topics relevant to the field and, consequently, offers a nice example on how these topics could be considered in other biomimetic systems. This review is intended to present a selection of some of the essential design principles that underlie the singular microstructure of major ampullate gland silk, as well as to show how the interplay between them leads to the outstanding tensile behavior of spider silk. Following this rationale, the mechanical behavior of the material is analyzed in detail and connected with its main microstructural features, specifically with those derived from the semicrystalline organization of the fibers. Establishing the relationship between mechanical properties and microstructure in spider silk not only offers a vivid image of the paths explored by nature in the search for high performance materials, but is also a valuable guide for the development of new artificial fibers inspired in their natural counterparts.

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Hydrothermal Effect on Mechanical Properties of Nephila pilipes Spidroin

Polymers ◽

10.3390/polym12051013 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1013 ◽

Cited By ~ 1

Author(s):

Hsuan-Chen Wu ◽

Aditi Pandey ◽

Liang-Yu Chang ◽

Chieh-Yun Hsu ◽

Thomas Chung-Kuang Yang ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Spider Silk ◽

Post Treatment ◽

Molecular Structures ◽

Random Coil ◽

Silk Fibers ◽

Physical Strength ◽

Β Sheet ◽

Post Treatment Process

The superlative mechanical properties of spider silk and its conspicuous variations have instigated significant interest over the past few years. However, current attempts to synthetically spin spider silk fibers often yield an inferior physical performance, owing to the improper molecular interactions of silk proteins. Considering this, herein, a post-treatment process to reorganize molecular structures and improve the physical strength of spider silk is reported. The major ampullate dragline silk from Nephila pilipes with a high β-sheet content and an adequate tensile strength was utilized as the study material, while that from Cyrtophora moluccensis was regarded as a reference. Our results indicated that the hydrothermal post-treatment (50–70 °C) of natural spider silk could effectively induce the alternation of secondary structures (random coil to β-sheet) and increase the overall tensile strength of the silk. Such advantageous post-treatment strategy when applied to regenerated spider silk also leads to an increment in the strength by ~2.5–3.0 folds, recapitulating ~90% of the strength of native spider silk. Overall, this study provides a facile and effective post-spinning means for enhancing the molecular structures and mechanical properties of as-spun silk threads, both natural and regenerated.

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Description of Test Setup and Approach to Measure Thermal Properties of Natural and Synthetic Spider Silks at Cryogenic Temperatures

Volume 8C: Heat Transfer and Thermal Engineering ◽

10.1115/imece2013-66630 ◽

2013 ◽

Author(s):

Troy Munro ◽

Changhu Xing ◽

Andrew Marquette ◽

Heng Ban ◽

Cameron Copeland ◽

...

Keyword(s):

Thermal Properties ◽

Conformational Changes ◽

Spider Silk ◽

Protein Structures ◽

Cryogenic Temperatures ◽

Nephila Clavipes ◽

Silk Fibers ◽

Spider Silks ◽

Better Than ◽

Natural And Synthetic

Spider silk is well-known for its exceptional mechanical properties, such as strength, elasticity and flexibility. Recently, it has been reported that dragline silk from a Nephila clavipes also has an exceptionally high thermal conductivity, comparable to copper when the fiber is stretched. Synthetic spider silks have been spun from spider silk proteins produced in transgenic sources, and their production process has the optimization potential to have properties similar to or better than the natural spider silk. There is interest to measure the thermal properties of natural and synthetic silk at cryogenic temperatures for use of spider silk fibers as heat conduits in systems where component weight is an issue, such as in spacecraft. This low temperature measurement is also of particular interest because of the conformational changes in protein structures, which affect material properties, that occurs at lower temperatures for some proteins. A measurement system has been designed and is being tested to characterize the thermal properties of natural and synthetic spider silks by means of a transient electrothermal method.

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