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  • Believe it or not, this is sharkskin.

  • And it's a little different

  • from your typical fishy scales.

  • It's made up of thousands of dermal denticles,

  • the toothlike structures you can see here.

  • And they're tough.

  • So tough that sharkskin by itself

  • can badly injure animals.

  • The trick to sharkskin is not just those denticles;

  • it's how they're structured.

  • All those denticles point backward,

  • making them smooth one way

  • but incredibly sharp and rough the other,

  • sort of like tiles on a roof.

  • That specific shape and alignment

  • interact with water in astounding ways.

  • Those grooved channels disrupt the flow,

  • forcing the water past and away from the shark's body,

  • significantly reducing drag

  • and even pulling sharks forward.

  • And unlike whales and manatees,

  • which are coated in barnacles and algae,

  • that same tiled pattern helps prevent those freeloaders

  • from hitching a ride on sharks.

  • And all of these properties have inspired engineers

  • to create the first antibacterial man-made pattern,

  • led, in part, by this man.

  • Tony Brennan: I am founder, chairman of the board,

  • and chief technology officer for Sharklet Technologies.

  • Narrator: Tony and his team have mimicked

  • the sharkskin pattern.

  • Brennan: This is a diamond shape that all shark scales have.

  • Narrator: And copied it onto a scalable surface.

  • Brennan: But when you try to draw that,

  • you end up with these two diamonds here that I've got.

  • Narrator: To work, the pattern Tony is holding

  • is scaled down to about 3 microns tall

  • and 2 microns wide.

  • Then it's imprinted onto a film,

  • creating millions of these microscopic channeled patterns.

  • Brennan: But if you look at this

  • and you look at this direction,

  • you see channels.

  • If you look at this direction,

  • you don't see any channels. It's walls.

  • That key element there provides an asymmetry.

  • And so water droplets behave differently,

  • depending on if you're tipping it this way,

  • this way, or at an angle.

  • Narrator: It's the precise alignment

  • of these asymmetrical lines and channels

  • that make it really hard for bacteria

  • to attach and colonize.

  • For bacteria to grow, they need a few things.

  • First, they like to be in a liquid droplet.

  • Brennan: So if I take this surface and I say to you,

  • I'm gonna take a droplet of water

  • and put it down on this surface.

  • Here comes the water droplet.

  • And if you look at this,

  • the water is not going down into the channels.

  • It's staying on top.

  • That's the major secret to Sharklet.

  • Narrator: Without being able to attach,

  • the droplet should simply roll off the Sharklet surface,

  • just like water pushes past typical sharkskin.

  • Secondly, bacteria like to stick together

  • and form what is known as a biofilm.

  • Christopher Jones: A biofilm's a community of bacteria

  • that adheres to a surface,

  • and they make their own matrix,

  • kind of like the glue or the cement

  • that will hold a bacterium to a surface.

  • And other bacteria can stick to that initial colonizer.

  • Narrator: Let's say a bacteria-filled droplet

  • fails to roll off the surface.

  • The bacteria will then fall into one of the many channels.

  • But the unique pattern makes it extremely difficult

  • for bacteria to find one another and link up

  • like they would on a smooth surface.

  • So while other antibacterial products

  • typically look to kill biofilms after they've formed,

  • Sharklet stops those biofilms

  • from forming in the first place.

  • This makes it especially useful in hospital settings.

  • With microorganisms unable to attach to the surface,

  • the film minimizes spread from surface to surface,

  • one of the main causes of disease transmission.

  • Jones: We show over 95% reduction in touch transfer

  • with Sharklet pattern compared to smooth

  • on multiple types of bacteria and fungi.

  • Narrator: That includes Staphylococcus aureus

  • and E. coli.

  • And Candida albicans, the fungi responsible for thrush,

  • showed over a 99% reduction in touch transfer.

  • And the pattern has also worked on viruses.

  • Recent work has looked at influenza B

  • and a coronavirus that's a close cousin of SARS-CoV-2.

  • Jones: And we show 80 to 85% reduction of transfer

  • of coronavirus and influenza

  • on our commercially available films.

  • Narrator: Since Sharklet is simply a film,

  • it can be applied almost anywhere.

  • In healthcare, they've begun adding it

  • to personal protective equipment

  • like face shields and gowns.

  • Jones: If you intelligently apply

  • where you put the Sharklet,

  • let's say things like elevator buttons, handrails,

  • doorknobs, things that are very high-touch surfaces,

  • you're really limiting the amount of exposure

  • from person to person.

  • Narrator: Yoga mats, pacifiers, pens,

  • and shopping carts are also being explored

  • and manufactured with the Sharklet pattern.

  • While the technology isn't a replacement

  • for cleaning surfaces, washing your hands,

  • or wearing face masks,

  • it's an additional tool that can help

  • fight the spread of diseases.

  • But Sharklet isn't alone.

  • Engineers are now using sharkskin as a model

  • for a whole heap of technologies,

  • like anti-barnacle paint, underwater robots,

  • and even on airplane wings to reduce drag.

  • So it's safe to say that you might not

  • look at sharks the same ever again,

  • and we've only just skimmed the surface.

Believe it or not, this is sharkskin.

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How Shark Scales' Unique Design Could Stop Bacteria Spread | Evolutionary Tech

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    林宜悉 posted on 2020/10/23
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