{"id":40265,"date":"2022-10-19T00:01:47","date_gmt":"2022-10-19T07:01:47","guid":{"rendered":"https:\/\/hakaimagazine.com\/?post_type=custom_news&p=40265"},"modified":"2022-10-18T20:47:55","modified_gmt":"2022-10-19T03:47:55","slug":"suiting-up-like-a-shark-is-still-a-struggle","status":"publish","type":"custom_news","link":"https:\/\/hakaimagazine.com\/news\/suiting-up-like-a-shark-is-still-a-struggle\/","title":{"rendered":"Suiting Up like a Shark Is Still a Struggle"},"content":{"rendered":"

Few people have gotten close enough to a shark to pet it. If you could run your hand from a shark\u2019s head to its tail\u2014not that you should<\/a>\u2014it would feel smooth, almost like suede. Reverse direction and it\u2019s rough like sandpaper. Viewed under a microscope, shark skin is composed of ribbed, dragonesque scales layered over each other like shingles on a roof. These structures, called dermal denticles, are more like teeth than skin. Made of dentin and enamel, they are innervated, and their ribbed and layered pattern guides water across the shark\u2019s back, reducing friction and drag. Sharks\u2019 impressive skin helps them glide through the water, with some species reaching speeds as fast as 50 kilometers per hour.<\/p>\n

Shark denticles are the envy of engineers. To mimic sharks\u2019 impressive hydrodynamic prowess, materials scientists have designed shark-inspired surfaces for the hulls of boats, wind turbines, and even high-end swimsuits, all in an attempt to maximize efficiency.<\/p>\n

But in a new study<\/a>, researchers from Harvard University in Massachusetts, led by ichthyologist Molly Gabler-Smith, have for the first time compared materials that attempt to mimic shark skin with the real thing. As it turns out, the engineered materials have a long way to go.<\/p>\n

Previously, scientists have examined shark denticles in impressive detail using scanning electron microscopes, a technology that can take images of structures just a few nanometers wide. But the images scanning electron microscopes put out are two-dimensional. And if you\u2019ve ever seen a car in a wind tunnel, you\u2019ll know that when it comes to reducing drag and friction, an object\u2019s 3D structure is incredibly important.<\/p>\n

So using a technique called surface profilometry, an imaging technology in which a scientist essentially uses a thin layer of gel to make a mold of the surface to be studied, Gabler-Smith and her team viewed shark skin in 3D. \u201cIt\u2019s almost like looking at a topographic map,\u201d says Gabler-Smith. \u201cYou can see where there\u2019s peaks and valleys.\u201d<\/p>\n

Gabler-Smith used the technique on skin samples from 17 different shark species. She also looked at two Speedo swimsuits marketed as mimicking shark skin\u2014the FS Fastskin II swimsuit and the Lzr Racer Elite 2\u2014as well as a 3D printed surface created in her lab. She compared the proportions of the denticles and the height and spacing of the riblets and found substantial differences between real shark denticles and the artificial materials.<\/p>\n

\"\"<\/a>

A close-up analysis shows the differences between real shark skin (top right) and several synthetic materials including a 3D-printed material (bottom right), the Speedo FS Fastskin II (bottom left), and the Speedo Lzr Racer Elite 2 (top left). Photos courtesy of Molly Gabler-Smith<\/p><\/div>\n

\u201cI hesitate to say that [the swimsuits are] really mimicking shark skin, because they really aren\u2019t at all,\u201d Gabler-Smith says. One of the biggest differences, she says, is that unlike a ribbed fabric, real shark skin is made of hard enamel structures on a flexible surface. When asked to rate the swimsuit materials out of 10, Gabler-Smith gave the FS Fastskin II and Lzr Racer Elite 2 a three and a seven, respectively, and her lab-made engineered surface an eight or nine.<\/p>\n

\u201c[The swimsuit designers are] doing a pretty good job of taking all of the information that biologists are measuring from actual shark skin, but there\u2019s still so much to do,\u201d she adds. In theory, she says, adding riblets or other bumpy textures to swimsuits or the surfaces of watercraft should reduce drag, but these surfaces are still a way off from functioning like the real thing.<\/p>\n

Amy Lang, an aeronautical engineer at the University of Alabama who studies shark skin and was not involved in the research, says that replicating the drag-reducing properties of shark skin is even more difficult than just having denticle-like riblets. To actually decrease drag instead of increasing it, she says, the riblets must be the right size and depth. She adds that while it is interesting to use surface profilometry to directly compare shark skin with engineered materials, it\u2019s equally important to test how synthetic materials actually work in the water.<\/p>\n

But now that scientists have updated information on the 3D structure of shark denticles across a variety of different species, engineers may be one step closer to mimicking one of nature\u2019s most efficient swimmers.<\/p>\n","protected":false},"excerpt":{"rendered":"

Few people have gotten close enough to a shark to pet it. If you could run your hand from a shark\u2019s head to its tail\u2014not that you should\u2014it would feel smooth, almost like suede. Reverse direction and it\u2019s rough like <\/p>\n

…<\/span><\/div>\n","protected":false},"featured_media":40268,"menu_order":0,"template":"","format":"standard","meta":{"_acf_changed":false,"om_disable_all_campaigns":false,"footnotes":""},"categories":[201],"tags":[],"acf":{"hero_video_url":null,"hero_video_caption":"","deck":"Shark skin is the envy of engineers trying to maximize hydrodynamics, but shark skin\u2013inspired materials have a long way to go before they work like the real thing.","authors_group":[{"by_group":"by","contributors_group":[36048]}],"word_count_override":"","podbean1":"","podbean2":"","redirect":"","geolocation":null,"related":[16896,37942],"twitterimage":40269,"facebookimage":40267,"twitterdescription":"","edited":[15491],"factchecked":"","code":"","no_old_story_flag":""},"_links":{"self":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/40265"}],"collection":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/types\/custom_news"}],"version-history":[{"count":6,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/40265\/revisions"}],"predecessor-version":[{"id":40275,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/40265\/revisions\/40275"}],"acf:post":[{"embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/profiles\/15491"},{"embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/37942"},{"embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/16896"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/media\/40268"}],"wp:attachment":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/media?parent=40265"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/categories?post=40265"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/tags?post=40265"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}