Is this tank safe for a snake?

Flexible snake armor

Press release 230/2012 from August 15, 2012 | to the print version | german version

Biology could inspire low-wear systems in technology




Snakes are highly specialized "legless" animals that arose 150 million years ago. Without extremities, however, your body is exposed to constant frictional forces. The doctoral student Marie-Christin Klein and Professor Stanislav Gorb from the Christian-Albrechts-Universität zu Kiel (CAU) have now found out how snakeskin specializes in legless locomotion: regardless of the habitat, it is stiff and hard on the outside, but soft on the inside and more flexible. Klein and Gorb have published their current results in today's issue (Wednesday, August 15) of the journal “Journal of the Royal Society Interface”.

Snakes inhabit all major ecosystems outside the polar regions. They manage to climb trees or dig themselves under the surface of the earth. The skin of a snake has to last two to three months before it begins to shed. "The snake skin must therefore be optimized against wear and tear," assumed Marie-Christin Klein at the beginning of her research. Together with Stanislav Gorb, she examined the skin of four species of snakes. The sand boa (Gongylophis colubrinus), the chain snake (Lampropeltis getula californiae), the rainbow boa (Epicrates cenchria cenchria) and the green tree python (Morelia viridis) inhabit different habitats from the desert to tropical trees. “With the help of these four species, we found out that the skin architecture is very different depending on the habitat. However, all of them have a gradient in the material properties. This means that even though snakeskin has different thicknesses and structures from species to species, all the hides are stiff and hard on the outside and soft and flexible on the inside, ”says Klein, explaining her discovery, which confirms her assumption that snakeskin is optimized for wear. The four types of snakes achieve this mechanical effect, for example, through different cell types. One type has thicker skin with round cells, the second has thinner skin with elongated cells. "This speaks in favor of a functional adaptation to legless locomotion, which has developed for snakes in both dry and wet areas," says Klein.

Klein continues to report that this research area is still largely untouched. “It is known how snakeskin is generally structured, but no one has yet investigated what effects this has on the mechanical properties of the material. A material that has a transition from a stiff outside to a more flexible inside can distribute the applied force over a larger area and reduce the point pressure. Such materials are like a flexible armor. ”Possible areas of application for this principle are in the field of medical technology. For example, friction in artificial prostheses could be optimized here. Furthermore, the drive and conveyor technology market could benefit from the knowledge that minimizes wear, since fewer lubricants would have to be used. The friction system of the snakeskin is an important model for this, which is used in bionics research at Kiel University (Department of Special Zoology, Professor Stanislav N. Gorb) for the development of new and for the optimization of existing materials in connection with friction and wear.

Original publication:
"Epidermis architecture and material properties of the skin of four snake species"
J. R. Soc. Interface rsif20120479; published ahead of print August 15, 2012, 1742-5662.
http://rsif.royalsocietypublishing.org

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Caption: Research object: snakeskin. Marie-Christin Klein, PhD student at Kiel University, researches how snakeskin protects itself against friction.
Copyright: CAU, Photo: Claudia Eulitz

Photo to download:
www.uni-kiel.de/download/pm/2012/2012-230-1.jpg

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Caption: Sand boa, Gongylophis colubrinus.
Copyright: CAU, Photo: Marie-Christin Klein

Photo to download:
www.uni-kiel.de/download/pm/2012/2012-230-2.jpg

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Caption: Chain snake, Lampropeltis getula californiae.
Copyright: CAU, Photo: Marie-Christin Klein

Photo to download:
www.uni-kiel.de/download/pm/2012/2012-230-3.jpg

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Caption: Rainbow boa, Epicrates cenchria cenchria.
Copyright: CAU, Photo: Claudia Eulitz

Photo to download:
www.uni-kiel.de/download/pm/2012/2012-230-4.jpg

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Caption: Green tree python, Morelia viridis.
Copyright: CAU, Photo: Marie-Christin Klein

Photo to download:
www.uni-kiel.de/download/pm/2012/2012-230-5.jpg

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Caption: Scanning electron microscope image of a cross section of the ventral scale of a chain snake.
Copyright: CAU, Photo: Marie-Christin Klein

Photo to download:
www.uni-kiel.de/download/pm/2012/2012-230-6.jpg

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Caption: The figure shows the force distribution for a material with and without a gradient at the same pressure.
Copyright: CAU, Photo: Marie-Christin Klein

Photo to download:
www.uni-kiel.de/download/pm/2012/2012-230-7.jpg



Christian Albrechts University in Kiel
Press, communication and marketing, Dr. Boris Pawlowski, editor: Claudia Eulitz, text: Marie-Christin Klein
Postal address: D-24098 Kiel, phone: (0431) 880-2104, fax: (0431) 880-1355
e-mail: [email protected]v.uni-kiel.de