[♩INTRO]
Let’s face it: life can be tough. And that means living things have to be tougher.
Organisms need to be ready for whatever nature throws at them — predators,
pounding waves, my fists, you name it.
I’m coming for you, bugs!
That’s why evolution has led to all sorts of clever armors.
And that’s something we humans can learn from.
Researchers are always looking for better ways to protect
people since our natural armor is pretty flimsy.
And they’re finding inspiration in some of the strangest places — like
in bizarre freshwater fish, all sorts of mollusks, and even spiders!
But first, gars kind of look like alligators with fins instead of legs.
This weird body plan hasn’t changed much in 100 million
years — which is probably thanks to their scales.
They aren’t your typical fish scales. They are incredibly strong. In fact,
people have used them as arrowheads and tools.
And now, they’re inspiring better puncture-proof gloves.
You see, researchers were impressed by just how tough the skin of these fish is.
You can’t get through it to the soft, edible parts with just any old pair of scissors.
You’re going to need tin snips or a hacksaw to get in — that’s some hefty protection right there!
Part of the reason their skin is so tough is that the scales are coated
in a mineral compound called ganoine which makes them hard and bone-like.
But also, they overlap with each other. And that makes them
really great at stopping even sharp objects from getting through.
It’s this interlocking pattern that has inspired engineers, because even though the fish are tough,
they can wiggle like—well, fish. So their armor is strong and flexible.
Researchers have mimicked their skin
by 3D printing tiny ceramic scales onto work gloves in the same pattern.
The results were quite good—the gar-inspired gloves were ten times more puncture
resistant than existing models, all while maintaining a similar degree of flexibility.
So they could protect people from being poked by sharp objects while still allowing them dexterity.
And that would be a huge step up for workers who have to sort through lots
of different materials — like those handling our recycling and garbage.
Chitons are mollusks, which means they’re in the same major group
of living organisms as snails, clams, and oysters.
And most live in the rocky intertidal zone: the wave-swept edge of the ocean.
This is rugged terrain.
In addition to the pounding of the waves, there’s always the risk of
being left exposed to the air and predators when the tide goes out.
So of course, chitons have several different ways to protect themselves from these threats.
But perhaps more importantly, their armor can see what’s coming!
Their entire bodies are wrapped in a thick leathery girdle. Think shapewear,
but for a slug, and made of muscle.
This flexible sheath helps them move around on uneven surfaces and suction tightly to the rock
if a predator or wave threatens to knock them off.
And attached to it are eight interlocking plates.
All this armor protects them much in the same way that the gar’s overlapping scales do.
But it can do something the gar’s can’t: it can see.
Their bodies are peppered with a bunch of tiny eye-like structures.
Researchers have known about these things for a while, but up until recently,
they didn’t think they were using them for vision.
That’s because the lenses of these eyes are made of crystalized calcium
carbonate — the same protective material as the chiton’s plate armor.
And that’s totally different from most other animals. Lenses usually consist of
squishy proteins, because they need to bend to focus on objects at different distances.
But it turns out these hard lenses work just fine! Chiton eyes can sense light and
dark and even form images — they just can’t focus those images the same way ours would.
More importantly, though,
the crystal structure of the carbonate contains multiple refractive indices.
That means it can bend the light enough to see it no matter what medium it’s traveling
through before it reaches the eye. So their eyes work the same in and out of the water!
Having eyes all over their bodies means chitons are able to see threats
approaching from any direction. That gives them time to clamp down tightly as needed.
And having hundreds of eyes means their vision isn’t interrupted if a few get damaged.
Researchers want to recreate this kind of seeing armor by 3D printing a material
that is both flexible, and impact resistant, and incorporates vision.
That way, the wearer knows what’s around them… something which would be especially handy for
military combat or in other volatile situations, like at the scene of a natural disaster.
They specifically want their eye-like objects to function much like the chitons’ — to be able
to see in both air and water, and keep working if a few get damaged.
If successful, this would be the first material of its kind — and
a huge advancement towards the creation of multifunctional armor.
Conchs are large marine snails, with hard, spiral shells.
And though these shells are mostly made of the same stuff as chiton plates and
other mollusk shells, they’re even stronger — which is why engineers think they could take
helmets and other protective equipment to the next level.
Conchs need extra-tough shells to survive their predators: like
ravenous crabs with strong pincers, and the tough beaks of hungry sea turtles.
But like their brethren, they start with something quite brittle: calcium carbonate.
To make this mineral tougher, they combine it with soft, wobbly proteins to form intricate,
three-tiered structures arranged in a crisscross-y pattern.
The complexity is the key here,
because it makes it so that even if a crack forms, it doesn’t spread.
Essentially, the design creates a maze that the crack has to travel through.
This makes their shells ten times stronger than nacre — one of nature’s strongest substances.
Before the invention of 3D printing, it was next to impossible to recreate these structures.
But now, engineers have successfully printed sheets in this same pattern, using both a
rigid and a squishy polymer to represent the calcium carbonate and proteins used by the conch.
This 3D printed material can resist cracking,
similar to the conch’s shell, as well as absorb energy from an impact.
And they’re hoping to use it in protective gear like sports helmets.
That way, they’d be more resistant to damage and absorb some of the energy of an impact,
which would better protect the wearer from traumatic injuries.
They could even print customized helmets for a perfect fit — something
not feasible now because there are too many materials involved in manufacturing them.
Anyone who’s ever walked through a spiderweb
knows that the silk that they spin is strong and stretchy.
In fact, the silks from orb-weaving
spiders often outperform the best synthetic fibers on the market!
They’re lighter, stronger, and they retain heat better than anything we’ve manufactured so far,
which is why some companies have already started using
them in everyday protective items like outerwear!
But now, researchers are hoping to use spider silk
as a replacement for another strong synthetic fiber: kevlar.
Kevlar is a popular choice for bulletproof vests because it’s lightweight and extremely strong.
But researchers think spider silk could be the key to an even lighter
and more flexible material — one that could absorb the energy of a bullet,
but still be stretchy enough to allow the wearer to move and bend with ease.
Two proteins, aptly named spidroin 1 and spidroin 2, form the basis of spider silk fibers.
The exact strength and stretchiness of the fiber
depends on how they’re arranged as well as what they look like.
You see, these two proteins can look a little different in fibers from
different parts of the web, or different species.
They can even vary depending on what the spider eats!
So researchers are still studying all these small variations hoping
to figure out the best silk for stopping bullets.
Though, even the stuff we have now is stronger and more flexible than kevlar.
The real reason it hasn’t taken over the market is that it’s tricky to mass produce.
We haven’t figured out how to spin this kind of silk in a lab, though a company in the United
States has genetically engineered silkworms that produce spider silk instead of their own silk.
And you might be wondering why we don’t just farm spiders.
Well, for starters, spiders sometimes eat each
other when kept in close proximity. Which makes things a bit trickier.
Plus, you’d have to have a whole separate farm for their prey!
Herbivores like silkworms are much easier to feed.
But more importantly, spiders require a lot of space to build their webs, while silkworms don’t.
So a spider farm would make the silk extremely expensive.
Besides, we’ve already got the infrastructure in place for silkworms.
Worldwide, more than 150 thousand metric tons of silk are made per year.
And if it ain’t broke, don’t reinvent the wheel, or something like that.
Now as incredible as super-kevlar, 3D printed helmets, or anything else
we’ve talked about so far would be, they have a weakness: fire.
So, to really be tougher than tough, they’d need a little help from a flame retardant:
something that’s applied to a flammable thing,
in order to slow down how quickly that thing will burn in a fire.
Unfortunately, growing evidence suggests that many of these chemicals are toxic
and can cause serious health issues, which is why these products are no longer applied
to everyday clothing, even though it could help save lives during a fire.
So many people are searching for non-toxic options for firefighters
and other workers frequently exposed to flames or sparks.
Researchers may have found a solution, though, in a somewhat unexpected place: mussels.
I mean the small, aquatic mollusks, not your biceps.
Now, it might seem strange that a water-dwelling animal would possess the means for stopping fires.
But they’re not using it for that. They’re using it to stay in place.
The substance is called polydopamine,
and it’s the waterproof glue that keeps them from being swept away by rough waters.
As an added bonus, researchers have discovered that it’s also a great flame retardant — for us,
not the mussels, seeing as they don’t experience a ton of fire.
It works by binding to molecules that get released by a substance as it burns.
These molecules, known as free radicals, typically end up adding more fuel to
the fire because they react with other compounds and make them more flammable.
By binding to free radicals, polydopamine slows down the speed at which the item burns.
It also generates a layer of char, that helps to block the fire’s access to the material.
And it does all this
really well. It outperforms many conventional flame retardants on the market today.
Not only that, polydopamine sticks to just about everything — which makes sense because
it’s a glue — so it could be applied to anything we want to make fire resistant.
Plus, it’s not toxic!
This means it could be applied to everyday wearable items,
or even the other armors on this list, to make them safely fire-resistant.
Though, researchers are particularly interested in using it to coat polyurethane foam,
the primary ingredient in many consumer products like furniture, mattresses, and car seats.
Thanks to these keen observations and newer
technologies like 3D printing and genetic engineering,
we’re already well on our way to making all kinds of futuristic, protective materials.
All scientists and engineers needed was a little inspiration to kick things up a notch.
And it’s only fitting that they’ve gotten that from the natural world.
Over millions of years, evolution has made it so that creatures on Earth
are well defended against a myriad of potential threats.
So it’s the best engineer around — and it always pays to learn from the best.
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[♩OUTRO]