Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi
Spider silks display generally strong mechanical properties, even if differences between species and within the same species can be observed. While many different types of silks have been tested, the mechanical properties of stalks of silk taken from the egg sac of the cave spider Meta menardi have...
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| Format: | Article |
| Language: | en_US |
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Public Library of Science
2012
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| Online Access: | http://hdl.handle.net/1721.1/71228 https://orcid.org/0000-0002-4173-9659 |
| _version_ | 1826199904710557696 |
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| author | Lepore, Emiliano Marchioro, Andrea Isaia, Marco Pugno, Nicola M. Buehler, Markus J |
| author2 | Massachusetts Institute of Technology. Center for Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Center for Materials Science and Engineering Lepore, Emiliano Marchioro, Andrea Isaia, Marco Pugno, Nicola M. Buehler, Markus J |
| author_sort | Lepore, Emiliano |
| collection | MIT |
| description | Spider silks display generally strong mechanical properties, even if differences between species and within the same species can be observed. While many different types of silks have been tested, the mechanical properties of stalks of silk taken from the egg sac of the cave spider Meta menardi have not yet been analyzed. Meta menardi has recently been chosen as the “European spider of the year 2012”, from the European Society of Arachnology. Here we report a study where silk stalks were collected directly from several caves in the north-west of Italy. Field emission scanning electron microscope (FESEM) images showed that stalks are made up of a large number of threads, each of them with diameter of 6.03±0.58 µm. The stalks were strained at the constant rate of 2 mm/min, using a tensile testing machine. The observed maximum stress, strain and toughness modulus, defined as the area under the stress-strain curve, are 0.64 GPa, 751% and 130.7 MJ/m[superscript 3], respectively. To the best of our knowledge, such an observed huge elongation has never been reported for egg sac silk stalks and suggests a huge unrolling microscopic mechanism of the macroscopic stalk that, as a continuation of the protective egg sac, is expected to be composed by fibres very densely and randomly packed. The Weibull statistics was used to analyze the results from mechanical testing, and an average value of Weibull modulus (m) is deduced to be in the range of 1.5–1.8 with a Weibull scale parameter (σ[subscript 0]) in the range of 0.33–0.41 GPa, showing a high coefficient of correlation (R[superscript 2] = 0.97). |
| first_indexed | 2024-09-23T11:27:40Z |
| format | Article |
| id | mit-1721.1/71228 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:27:40Z |
| publishDate | 2012 |
| publisher | Public Library of Science |
| record_format | dspace |
| spelling | mit-1721.1/712282022-10-01T03:47:09Z Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi Lepore, Emiliano Marchioro, Andrea Isaia, Marco Pugno, Nicola M. Buehler, Markus J Massachusetts Institute of Technology. Center for Materials Science and Engineering Massachusetts Institute of Technology. Center for Computational Engineering Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Massachusetts Institute of Technology. Laboratory for Atomistic and Molecular Mechanics Buehler, Markus Jochen Buehler, Markus J. Spider silks display generally strong mechanical properties, even if differences between species and within the same species can be observed. While many different types of silks have been tested, the mechanical properties of stalks of silk taken from the egg sac of the cave spider Meta menardi have not yet been analyzed. Meta menardi has recently been chosen as the “European spider of the year 2012”, from the European Society of Arachnology. Here we report a study where silk stalks were collected directly from several caves in the north-west of Italy. Field emission scanning electron microscope (FESEM) images showed that stalks are made up of a large number of threads, each of them with diameter of 6.03±0.58 µm. The stalks were strained at the constant rate of 2 mm/min, using a tensile testing machine. The observed maximum stress, strain and toughness modulus, defined as the area under the stress-strain curve, are 0.64 GPa, 751% and 130.7 MJ/m[superscript 3], respectively. To the best of our knowledge, such an observed huge elongation has never been reported for egg sac silk stalks and suggests a huge unrolling microscopic mechanism of the macroscopic stalk that, as a continuation of the protective egg sac, is expected to be composed by fibres very densely and randomly packed. The Weibull statistics was used to analyze the results from mechanical testing, and an average value of Weibull modulus (m) is deduced to be in the range of 1.5–1.8 with a Weibull scale parameter (σ[subscript 0]) in the range of 0.33–0.41 GPa, showing a high coefficient of correlation (R[superscript 2] = 0.97). Presidential Early Career Award for Scientists and Engineers (award number N00014-10-1-0562) 2012-06-27T19:12:15Z 2012-06-27T19:12:15Z 2012-02 2011-10 Article http://purl.org/eprint/type/JournalArticle 1932-6203 http://hdl.handle.net/1721.1/71228 Lepore, Emiliano et al. “Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta Menardi.” Ed. Brock Fenton. PLoS ONE 7.2 (2012): e30500. Web. 27 June 2012. https://orcid.org/0000-0002-4173-9659 en_US http://dx.doi.org/10.1371/journal.pone.0030500 PLoS ONE Creative Commons Attribution http://creativecommons.org/licenses/by/2.5/ application/pdf Public Library of Science PLoS |
| spellingShingle | Lepore, Emiliano Marchioro, Andrea Isaia, Marco Pugno, Nicola M. Buehler, Markus J Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi |
| title | Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi |
| title_full | Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi |
| title_fullStr | Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi |
| title_full_unstemmed | Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi |
| title_short | Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi |
| title_sort | evidence of the most stretchable egg sac silk stalk of the european spider of the year meta menardi |
| url | http://hdl.handle.net/1721.1/71228 https://orcid.org/0000-0002-4173-9659 |
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