Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student Gardner makes this connection here…

The article titled “Why Are Scientists Trying to Make Fake Shark Skin?” was posted as an online article on the Smithsonian’s website on August 11, 2014. This article relates to the WRE domain of hydrology and the specific issue of water movement. In summary, the article is discussing the uses of synthetic shark skin which is a biomimicry example of shark denticles. The article expands into discussing previous applications like Speedo’s SharkSuits and other applications thanks to advances into 3-D printing and computer modeling. The article is indeed interesting while discussing the applications for synthetic shark skin. However the article does a poor job of explaining what makes shark denticles so successful in reducing drag. Through outside research, I was able to understand the denticle structure as well as how water moves over them. Denticles are flat and teeth-like and cover a shark’s body similar to scales on a fish (Figure 1). The shape and texture of the denticles vary over the shark’s body, matching the way water flows over the different parts (Dean). Denticles will actually disrupt how water flows over a shark’s body (Figure 2). Jaywant Arakeri in his work entitled “Fluid Mechanics of Fish Swimming” proves to be helpful in applying the Reynold’s number equation and explaining how different sized fish have different drag-reductions. Water resources engineering impacts our lives through many different means such as its influences on the global, economic, environmental, and societal scales. Every minute of every day, millions of people are relying on hydrologic and hydraulic systems for their needs. Synthetic shark skin can prove to be an essential element in our lives through its applications like anti-microbial door handles and swimsuits. Research is currently underway to work towards using synthetic shark skin as a defense against biofouling on ship hulls. Currently, anti-fouling paint is toxic and using shark skin would be an environmentally-friendly option (Thompson). The possibilities for advances in underwater robot design could also prove to be valuable for our future world. Using synthetic shark skin, these underwater robots could have more flexible bodies whose motions could resemble a real fish. Airplane wings might even be able to be designed to be more energy-efficient if synthetic shark skin can be utilized. And then in the biological spectrum, through research with denticles, scientist are learning even more in regards to the swimming forces of sharks and other fish. George Jeronimidis was even quoted in Thompson’s article saying it’s currently a rapidly growing field and that “we are just beginning to understand how integrated and functional the skin of marine creatures is.” Through advances in technologies, our world can learn how to perfect their synthetic shark skin and apply its many uses of anti-microbial and drag reduction to help each of us in our daily activities.

Images

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Figure 1: A close-up of a shark’s denticles showing their shape, arrangement, and proximity to one another.

shark_skin

Figure 2: Because of a shark’s denticles bristling and their alignment, water is able to smoothly flow over the shark’s surface instead of creating eddies and vortices that cause drag and friction.

URL

http://www.smithsonianmag.com/innovation/why-are-scientists-trying-to-make-fakeshark-skin-180951514/?no-ist

References

Arakeri, Jaywant H. “Fluid Mechanics of Fish Swimming.” Resonance 14.1 (2009): 32-46. Web. 10 Feb. 2015. Dean, Brian, and Bharat Bhushan. “Shark-Skin Surfaces for Fluid-drag Reduction in Turbulent Flow: A Review.” Philosophical Transactions of the Royal Society: Mathematical, Physical and Engineering Sciences 368.1929(2010): 4775-806. Web. 10 Feb. 2015.

Saltarin, Alexander. “3D-printed Shark Skin Demonstrates How Denticles Boost Swimming Speed.” Tech Times RSS. Tech Times, 15 May 2014. Web. 10 Feb. 2015. Schleck, Dave. “Speedo Suit Helps Athletes Swim Like Sharks.” Daily Press (Newport News, VA) (n.d.): Newspaper Source Plus. Web. 11 Feb. 2015.

Thompson, Helen. “Why Are Scientists Trying To Make Fake Shark Skin?” Smithsonian. Smithsonian, 11 Aug. 2014. Web. 10 Feb. 2015.

Wen, Li, James C. Weaver, and George V. Lauder. “Biomimetic Shark Skin: Design, Fabrication, and Hydrodynamic Function.” The Company of Biologists Ltd 217 (2014): 1656-666. Web. 10 Feb. 2015.

Images

http://ocean.si.edu/ocean-photos/biomimicry-shark-denticles https://snowbio.wikispaces.com/Dogfish+shark

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