There are two innovations of particular importance. Let’s first briefly look at the use of the material itself. Speedo has gone to great length to study the human body while swimming, and place bands of fabric in all the right places. Mimicking the muscles and tendons of great swimmers, the stretchy polyurethane can increase muscle compression and help maintain muscle shape to reduce fatigue and power loss. This is a simple, yet effective case of bionics.
Thus, a shark’s skin can:
• Channel the direction of water flow;
• Use riblets to reduce the difference in water speed at the skins surface as compared to the water speeds beyond the skin (think of wind howling through a canyon); and
• Reduce turbulence by breaking up water flow hence creating many small turbulences rather than larger vortices.
Relate this back to the “Life’s Principles” (developed by the Biomimcry Group) mentioned in the previous blog. Sharkskin is a great teacher of what is meant by Fit Form to Function. The shape of the shark denticles are what allow the shark, and now competition swimmers, to move efficiently through the water with lesser effort.
Recalling another of the Life’s Principles, Use Multi-Functional Design, I’d like to bring this back to the medical device community. At about the same time Speedo made their discovery of shark skin, Dr. Anthony Brennan looked at slow moving sharks. Unlike whales, sharks do not have a buildup of barnacles or other micro-organisms. As it turns out, the shape that allows sharks to move fast through water also discourages microorganisms from attaching to the sharks skin. In fact, Dr. Brennan found that green algae settlement was reduced by 85 percent… enough to prevent a colony from being able to take hold. While conducting further research for the U.S. Office of Naval Research, Dr. Brennan discovered other uses for this technology. He then started Sharklet Technologies, Inc. which focuses on antimicrobial and antibacterial technologies. Some of the focus has been on antibacterial surfaces for hospitals (e.g. nurse call buttons) as well as medical devices (e.g. urinary tract catheters).
Until next time,
Rob Lichty
