Home Uncategorized New super-hydrophobic metal makes water bounce like crazy

New super-hydrophobic metal makes water bounce like crazy

While in past hydrophobic materials depends on chemical
coatings to repel water, this new metal has the property built right into it.
This means water molecules will never bond to it and bounce like crazy.
US Researchers have invented an incredible self-cleaning metal that is so
super-hydrophobic, water droplets will just keep bouncing off it until they
roll away. Inspired by natural materials such as the water-repellent lotus
leaf, super-hydrophobic materials have been popping up all over the place of

We’ve seen a new, super-durable, super-hydrophobic coating for use in power
plants announced
in 2013
, a spray-on coating for boots and airplanes announced in
, and just a few months ago, researchers from China invented a
super-hydrophobic coating that’s so good, it
can even be used on sex toys
. A couple of weeks ago, I got the opportunity
to test-run a new Australian-made
super-hydrophobic t-shirt
, and watched as little droplets of tomato and soy
sauce rolled all over its pristine white surface. 

But as cool as each of these inventions are, the effect will eventually wear
off on each and every one of them, because the materials are coated in a
super-hydrophobic substance – they aren’t super-hydrophobic themselves. And
that’s why this new metal is so exciting. It has its super-hydrophobic
properties built right into it, which means it will remain effective

Chunlei Guo, Professor of optics at the University of Rochester said in a press release,
“We are able to change the surface structure of almost any piece of metal so
that we can control how liquid responds to it and we can even control the
direction in which the liquid flows, or whether liquid flows at all.”

To create the self-cleaning material, Guo’s team blasted the surface of an
alloy made from platinum, brass and titanium using an ultra-fast burst of laser
light. And when we say “ultra-fast”, we mean it – each burst is a
mere femtosecond long,
which equates to just a few quadrillionths of a second ( or as the team describes,
“a femtosecond is to a second what a second is to about 32 million year)
and unleashes as much power as the entire electric grid of North America does,
all focused onto a spot the size of a needlepoint.”

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These bursts alter the structure of the metal on a nanoscale, creating
minuscule pits, globules and strands all over the surface. These nanostructures
determine how much or how little liquid molecules are attracted to the surface
molecules of the metal, and the effect can be turned up or down depending on
the setting of the laser. This means that on one setting, the metal can be
rendered super-hydrophilic, which means it bonds incredibly well with liquids,
causing them to spread rapidly across the surface like a big hug. On another
setting, it will become super-hydrophobic, causing the liquid to bounce right
on out of there.

Guo said., “Imagine
a huge waterway system shrunk down onto a tiny chip, like the electronic
circuit printed on a microprocessor, so we can perform chemical or biological work
with a tiny bit of liquid. Blood could precisely travel along a certain path to
a sensor for disease diagnostics. With such a tiny system, a nurse wouldn’t
need to draw a whole tube of blood for a test. A scratch on the skin might
contain more than enough cells for a micro-analysis.”

Also, their metal is black, which means it will be extra useful for
applications where light collection is required, such as sensors and solar
panels, they
report in the journal

Applied Physics Letters
. Their material is self-cleaning,
anti-corrosion, anti-icing, and anti-microbial. Imagine air conditioners and
fridges that never accumulate ice, shelves that never need dusting, and
surfaces that harmful microbes can never take up residence on. 

The invention has even caught the attention of the Bill and Melinda Gates
Foundation, because of its potential to facilitate the easy collection of rain
water in developing countries around the world. “In these regions, collecting
rain water is vital and using super-hydrophobic materials could increase the
efficiency without the need to use large funnels with high-pitched angles to
prevent water from sticking to the surface,” Guo said in the press
. “A second application could be creating latrines that are cleaner
and healthier to use.”

But, as
Alexandra Ossola says at Motherboard
, “it’s nowhere near ready to be deployed
in those real world scenarios where it’s most needed”. Right now, it takes one
hour to laser-pattern a 2.5 cm by 2.5 cm sample of metal, which is just not
feasible when you want to be creating huge funnels and toilets with the stuff.
But it’s still super-fun to watch it work, even if we have to wait a while to
see it muscle its way into our lives.
Source: Youtube