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