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If you're watching this video on a laptop in-between watching more cat videos, you may
have noticed the sound of fans whirring away, trying to keep your slim technological miracle
of form and function cool.
Heat is a natural enemy of electronics, it can cause computers to slow and crash, and
damage important hardware to boot.
So scientists at Duke University have been exploring a new technique inspired by insect
wings to keep your CPU as cool as you are.
The concept behind every cooling system ever is basically the same: take heat from a hot
area, move it to somewhere less hot, repeat ad infinitum.
The details of how different systems do this exactly can vary a lot, and they range from
simple to ingenious.
Heat sinks just let the electronics warm a set of metal fins with a large surface area
while a fan blows cool air over the fins.
The air warms up, absorbing the heat, and then is blown away.
Only the most powerful pre 90s computers needed these but now they're a staple of home computers
and have made higher processing speeds possible.
Heat pipes contain liquid and use heat to turn it into a vapor, which then travels to
a cooler part of the pipe to condense again.
The liquid then naturally flows back to the hot areas along grooves on the inside of the
pipe because the liquid is attracted to the material, a phenomenon called capillary action.
No pumps or gravity are required, so this is the technique many satellites use to manage
heat in space.
Like a heat pipe, the new system developed at Duke also uses vaporizing liquid as a means
to carry heat away.
A sponge-like material filled with liquid rests just under the surface that needs to
be cooled.
The liquid absorbs the heat until it turns into vapor and leaves the sponge -- taking
the heat with it.
Below the sponge is a cool surface for the liquid to condense on, but it's been specially
designed to be superhydrophobic.
I'm not talking regular hydrophobic, like oil and water.
I mean super-hydrophobic like a cat, it actively repels it.
It does this by mimicking the microscopic bumps on the wings of a cicada.
Condensing water droplets sit on these bumps like a person sits on a bed of nails.
When droplets merge though, they leap into the air.
This is because when the two droplets come together, their overall surface area is reduced.
The energy that was once used to keep the droplets flat on the hydrophobic surface is
suddenly released, popping the drop straight up.
Cicadas use this phenomenon to keep their wings clean, while the cooler uses it to return
liquid to the sponge.
There are a few benefits of a cooling system like this.
It works in any orientation and is independent of gravity.
It can also passively cool moving hotspots that naturally occur; If an area of the electronic
device gets hotter than the rest, it'll just evaporate more liquid from the sponge.
Other techniques either can't target hotspots at all -- making them ill suited to cool large
areas -- or they have to use power to target moving hotspots, making them less efficient.
The technology has a ways to go before it's ready, as the scientists have to find materials
that will last long term, but they're optimistic about their progress so far.
After working on this for a few years, the researchers claim their technique is on par
with the performance of the most common technology used now: copper heat spreaders, but has the
potential to surpass it.
While new technologies that promise to make high performance electronics and electric
cars better is exciting, my favorite part of the story is the researchers who developed
this technology are the same ones who first observed how cicada wings repelled water.
Back in 2013 they suggested it might be used as a way to cool devices, and here we are
four years later and they're doing exactly what they imagined they would.
Don't you love the progress of science?
You're probably watching this video on a phone or a computer right now, hopefully it's
cool, but is staring at screens all day really bad for your eyes?
Check out this episode to find out.
Got a science question you'd like us to answer?
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Thanks for watching