They started with striped bass. Over a two-year period the researchers went through about 50 bass, puncturing or fracturing hundreds of fish scales under the microscope, to try to understand their properties and mechanics better. 鈥淭he people at the fish market must have wondered what we were up to,鈥� says smiling ruefully.鈥� He teaches in the Dept. of Mechanical Engineering at 91社区, and is one of a who look to nature for inspiration as they search for solutions to engineering problems they see around them today. For several years, he and his team have been trying to replicate the kind of protection combined with flexibility offered by certain kinds of animal scales. Their goal is to create protective gloves that are both resistant to piercing and still flexible enough for factory workers to work in. After five years of work, they believe they have done it.
The solution came when they started looking more closely at the scales of an alligator gar.
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Smaller is sometimes better
Through a series of experiments the researchers were able to identify a set of critical mechanisms in the way natural fish scales deform, interact, and fracture. They also developed a new technique to cover large surfaces with a shell of overlapping ceramic tiles. By using computer modeling, they were able to determine the optimal size, shape, arrangement and overlap to make protective gloves which are much more resistant to piercing than those currently in use.
鈥淔ish scales surprised us,鈥� says Roberto Martini, a post-doctoral fellow and the lead author on a paper the team recently published about their work. 鈥淚t may sound counter intuitive, but we discovered that smaller scales are actually more difficult to pierce than the larger ones, something we can now fully explain using engineering analysis. We also learned that they are the toughest collagen-based material known.鈥�
Nature solves engineering problems
鈥淣ature has been finding solutions to 鈥榚ngineering problems鈥� over millions of years of evolution鈥� adds Barthelat. 鈥淔or a long time biologists and engineers largely ignored each other, but this is now changing. Biologists are using more and more engineering tools and methods, and engineers are revisiting old engineering problems using bioinspiration. Biologists and engineers are now talking to each other more than ever before, which is very stimulating and makes it is a very exciting time to be working in this field.鈥�
This research was supported by the Natural Sciences and Engineering Research Council of Canada and by a Team Grant from the Fonds de recherche du Qu茅bec鈥擭ature et Technologies.
To read 鈥淪tretch-and-release fabrication, testing and optimization of a flexible ceramic armor inspired from fish scales,鈥� by Robert Martini and Fran莽ois Barthelat, Bioinspiration and Biomimetics: 听
Contacts:
Fran莽ois Barthelat, 91社区, Department of Mechanical Engineering
Francois.barthelat [at] mcgill.ca
Katherine Gombay, 91社区, Media Relations
katherine.gombay [at] mcgill.ca, 514-398-2189
A selection of coverage of earlier bioinspired work by Francois Barthelat:
Snail Shells Are Inspiring Tomorrow's Toughest Materials:
Le verre dans tous ses 茅clats听:
Qu茅bec Science - Les dix d茅couvertes de l鈥檃nn茅e 2014 - Comme les coquillages听:
