The recent Biomimetic line of tennis racquets from Dunlop inspired by animal biology may be one of the latest in a series of racquet technologies that leaves skeptics unimpressed. These technologies are often dismissed as gimmicks and the argument that the Roger Federers and Victoria Azarenkas of the sport would still play well with almost any racquet appears once again. The skeptics do have some validity to their argument. However, the technology that Dunlop uses is either being used or researched for other products and industries.

Honeycomb Patterns: What Works Well for Bees Also Works Well in Aerospace and Other Products

The HM6 Carbon technology that Dunlop uses in Biomimetic racquets takes advantage of the strength and efficiency of the honeycomb pattern. Without getting into too much math, if you want to build a structure of hollow cells that is strong but requires the least amount of material, the hexagonal pattern of the honeycomb is the way to go.

One publicly traded company, Hexcel Corporation, has been in existence since 1946, finding new ways to use honeycomb patterned structures in products ranging from aerospace to snowboards. When Neil Armstrong became the first person to set foot on the moon, the footpads of the lunar module used hexagonal material made by Hexcel. Their materials were also used in the Concorde supersonic airliner and are used today in snowboards and skis. All of these applications in their own way put stress on the materials that they are constructed from. It says a lot about the strength of hexagonal patterned material that they continue to be used today.

Shark Skin: A Smooth Surface is Not Always The Most Aerodynamic

The preceding heading seems to defy the common sense that a smooth surface will have the least amount of drag. Anyone who has ever thrown a curve ball in a baseball game appreciates the benefits that the seams provide in making a pitch move so the batter cannot hit it with any authority. If baseballs were perfectly round, smooth spheres, pitches would not have near as much movement.

But aerodynamics is a complex study and what works in some applications does not seem to work in others. Dunlop developed Aeroskin technology based on the riblets on a shark’s skin that help the feared predator move through the water with streamlined efficiency. It’s supposed to cut down on air drag when you swing the racquet.

Other examples demonstrate that a smooth surface is not the best aerodynamically. Golf balls have long had dimpled surfaces because they fly better through the air than a ball with a smooth surface would. On the television show, Mythbusters, the hosts compared the gas mileage of a car with a dimpled surface vs. a smooth surface.

They ran one mileage test with the car in its original configuration. In the next round, they covered the car with a layer of modeling clay smoothed to follow the original contours of the car’s surface and performed another mileage test. In the third test, they cut out over 1,000 dimples in the clay surface and ran a mileage test. The clay remnants from cutting out the dimples were put in a box and kept in the back seat during the test so that the weight of the dimpled car would not differ significantly from the weight of the car with a smoothed layer of clay on it.

The end result was that the dimpled car got 29 MPG in the test while both the smooth car and the original car without clay on it got about 26 MPG. This seems to confirm that dimpled surfaces lead to better gas mileage, right?

Not so fast. Dallas based FastSkinz makes an adhesive dimpled skin that is supposed to improve on fuel efficiency. However, a Popular Mechanics test from October 2009 showed that if anything, the Fastskinz surface decreased fuel efficiency.

So why the differences? The Mythbusters test car had fewer larger dimples than the Fastskinz covered car did, so the surfaces are significantly different. The Mythbusters testers, Jamie Hyneman and Adam Savage only tested with only one car. They had to go through the time consuming process of testing the car with no clay, then put smooth clay on the surface and test that configuration. Then they had to go through the time consuming process of dimpling the car.

The Popular Mechanics test used two cars that were the same model and both had about 8,000 miles on their respective odometers. One car was ‘skinned’ and the other wasn’t. The cars performed the test at the same time on freeway conditions. Hyneman and Savage had to test the same car at three different times. It’s conceivable that weather conditions affecting drag like wind and humidity would have been different all three times. Aerodynamics is indeed a complex study.

One company that would seem to back up Dunlop’s use of Aeroskin technology is the global aerospace manufacturer Airbus. While there is no example of it in use on current aircraft, the company states the following on its website:

“…this “groovy skin” concept, or riblet as it is referred to in the industry, has been investigated and tested by aerospace engineers and eventually will be adapted and applied to the construction of Airbus aircraft.”

Interestingly enough, the above statement from Airbus came from a page full of examples of biomimicry similar to what the company promotes with their Dunlop Biomimetic tennis racquets.

What Allows a Gecko to Hold Its Grip May be Used in Medical Bandage Technology

Dunlop’s Gecko-Tac Grip technology is supposed to help you grip the racquet better than with other grips, even in the presence of moisture. Researchers from the University of Akron have been researching a similar concept by testing the ability of Geckos to grip many surfaces, even under humid tropical conditions. The objective of the study is to develop adhesives in medical bandages that will maintain their adhesion in moist conditions.

Conclusion

Very few of us have the budget or scientific know-how to test any claims by Dunlop about the technologies found on their Biomimetic series of racquets. That other companies and organizations have used or are testing these principles to make better products shows that Dunlop’s claims at least have some credibility to them. It also makes you appreciate what Mother Nature created and how we can learn from it when applied correctly.

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Christopher Mohr is a freelance writer from San Diego, Calif. who enjoys covering topics including sports, athletic equipment and technology.