Harvard scientists have used 3D printing in order to produce a scaled-up replica of a mako shark’s skin which has demonstrated how microscopic tooth-like scales improve the shark’s swimming efficiency. The study has been published inThe Journal of Experimental Biology.
The advantage these denticles bequeathed was immediately apparent; the artificial toothy skin boosted swimming speed by 6.6% when compared to a device with a smooth control coating. Furthermore, the artificial shark skin reduced energy expenditure by 5.9%.
By imaging the flow of water as the device was in motion, the team were able to discern that the denticles also produced a stronger leading-edge vortex than the smooth control, which is a low pressure whirlpool produced by the movement of the device. According to Lauder, this finding could be very important since it suggests that rather than just reducing drag, the denticles may actually increase the thrust. “It can help suck the fish forward,” he added.
would posit that the denticles aren’t just to provide less water resistance then a smooth surface, they evolved to work in conjunction with the muscular contractions that occur over the entire surface area of the fish as it swims, increasing speed due to sum net of hundreds of thousands of denticles being essentially ‘flippered’ as the fish undulates, and also provide more claw grip against the water when the fish contorts into tight turns, increasing the angle of attack.
would think that surface could be 3D produced for a bonded overlay for surfboard bottoms. Be interesting to run a beta and see if there is a noticeable difference. If so, game on…
Bill ,if Paul Gross is reading this would be an interesting expirement for a surf mat if cloth were available ???Where the properties of changing?undulation are way more apparent than a rigid surfboard Paul or surffoils mat builder?? Although surf mat canvas/nylon sort of has a texture HHHMMM… I have a need for speed!!!
Interesting information Mr. Barnfield. Thanks for posting it. This 3-D printer work by Lauder and colleagues is a brilliant idea for shark skin research.
Lauder did some earlier work (2012) with actual shark skin applied to solid surfaces. The results were interesting. It seems denticle and ridge spacing, size, geometry and dimension are important. I believe these variables differ with the average velocity of the fish/object.
NASA developed a ribbed plastic film with 3-M for use on aircraft to reduce drag – using shark skin as their model. It was effective, 8% drag reduction on a lyre jet. This ribbed film technology was also applied to the hull of the winning Americas Cup racing sailboat, Stars and Stripes. It was used effectively by US olympic kayak racers too in early qualiftying heats.
Spell check is happy with lyre, leer and Lear. It liked pier reviewed rather than peer reviewed once also, fortunately I caught that one in an application letter for a publishing job.
This subject of, surface finishes and treatments, has been discussed many times and always seems to remain a mystical unresolved design element. I guess surfers and surfboard makers prefer things to remain subjective rather then objective. Endless speculation is way more fun than the difficult task of actually testing options and figuring stuff out.
since the entire outside of my brand spanking never used mike daniels custom coil is covered in small dimples about the size of those teeth, i believe charlie was joking that those things were used like a reverse woodworking call while vacuum bagging to create the famous coil patented golf ball like “dimple effect”
I was sitting out in the water today thinking about this subject. I got to thinking that there are other fast animals in the sea that don’t have rough skin like sharks do. The question that springs to mind is why do sharks have rough skin? Is it to swim fast? Or is it for some other reason? Also Sharks are cylindrical and swim under the water, while surfboards are basically flat and are propelled (mostly) by the energy of breaking waves, on top of the water, with a person standing on them. Sharks and surfboards seem like quite different things to me.
I dunno, I guess it’s probably worth a try though.
this is a good point. dolphins, tuna, other fast animals are smooth. olympic swimmers are now using smooth compression suits.
like bill said, this topic has been discussed before, and I remember some experienced guys saying that glossed boards were slower. agreed that objective testing is needed, but how much difference would a rough vs. smooth surface make? would a surfer be able to feel it? why don’t all marine animals have the same surface if one is the fastest?
For many years Marine Biologist were baffeled by Sharks ablity to swim as fast as they do. The shark anatomy says they should so fast yet they were swimming at much faster speeds. This problem was solved when they took a close look at the skin. The shape of the denture was the key. There have been studies done for the hulls of ships and aircraft with signs that the texture does make a vessel more slippery in the water and air. Nissan is building a car carrier ship based on shark skin texture they are hoping for a major savings in fuel cost. Perhaps there is some PHD candidate at MIT that could cut the shark skin texture into the bottom of a Board with a laser. It would be an interesting experiment. Bill Thanks for bring this back up. It’s not just about texture it’s about a specific design of texture.
The coil dimple effect is as far from subjective as one can get. Fun factoid. When tube riding a coil product you will have to drag your hand in the barrel 6.6% more to stay perfectly pitted. Out of the bag mako shark skin on bottom totally doable with vacuum bagging. All you people making a living sanding surfboards, share holders in surfboard abrasives and sanding power tools. So sorry for your loss.
