Michelle Dickinson: nanotechnologist on new research revealing the dark side of eyelash treatments

Ever been caught in the rain and wondered how your vision stays relatively clear? You can thank your eyelashes for that! Recent research published in Science Advances reveals that our lashes do more than just keep out dust - they’re also masters of water management. 

The researchers found that eyelashes are equipped with a special microstructure made up of tiny overlapping scales. These scales act like a 'micro-ratchet', allowing water to flow smoothly from the base to the tip while preventing it from reversing direction. 

Eyelashes are also naturally hydrophobic, meaning they repel water. When water lands on your lashes, it forms tiny droplets that bead up and roll away. This clever mechanism ensures your eyes stay dry and your vision remains unobstructed. 

The magic of eyelashes doesn’t stop at their hydrophobic properties. Their curved shape is called a brachistochrone, a design that minimises the time it takes for water to move under the force of gravity. This natural curve helps lashes efficiently direct water away from your eyes. 

Unfortunately, common beauty practices can strip away these natural benefits: 

Mascara coated lashes are hydrophilic, meaning they attract water instead of repelling it. This can make them less effective at keeping your eyes dry. 

Curling lashes disrupts their natural brachistochrone shape, reducing their ability to efficiently expel water. 

Beyond their protective role, the unique structure of eyelashes has inspired engineers to think about new ways to manage liquids. Here are a few ideas sparked by this research: 

Advanced Drainage Systems: Eyelash-inspired designs could improve waterproofing for outdoor devices, drones, and wearable electronics. 

Self-Cleaning Materials: Mimicking the hydrophobic scales of eyelashes could lead to better anti-fogging glasses and self-cleaning surfaces. 

Efficient Liquid Management: Protective coatings for screens and other electronics could benefit from the same principles that keep your lashes dry. 

So next time it rains, take a moment to appreciate the remarkable engineering of your lashes - they’re doing more for you than you might think! 

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Episode Transcript

Speaker 1 (00:06):
You're listening to the Sunday Session podcast with Francesca Rudgin
from News Talks.

Speaker 2 (00:11):
It'd b doctor Michelderkinsnano girl, welcome. Good to have you
back with us in twenty twenty Five's.

Speaker 3 (00:18):
Good to be back.

Speaker 2 (00:19):
Had a nice summer.

Speaker 3 (00:20):
It's been lovely. Oh good, We've been lucky up here
in Okland. It's been good. Sorry Wellington, No.

Speaker 2 (00:24):
I know. Look, it has been about Dodgy and certain
parts of the country and that's where our wonderful eyelashers
will have.

Speaker 1 (00:30):
Been very useful.

Speaker 3 (00:32):
This is a study that I was like, how did
we not know this? But apparently we didn't know. So
new word of the day for those of you who
are looking for something fresh for the new year is
I'm going to break it down for how to pronounce it.
It's called a brah Christist brah christal crone for christa
crone for christa cone. It's a physics mathematical word for chrystal.
Anyway you to that one, you can take it to

(00:54):
your water cooler. It is basically the fastest path between
two points using gravity in maths. So, Jessica, if you
and I were going to give a ball to each other.
I was at the top of it and you were
at the bottom of the hill a little bit further away.
What is the fastest way using gravity that the ball
could get to you? And people usually go, oh, just
put a slide down and it just goes straight down

(01:15):
the slide, a linear slide is not the way. The
way mathematically I can get the ball faster to you
is to sort of have a slide that was shaped
a bit like the second half of a roller coaster,
so a really steep slope and then a curve flick
up with ski jump just like that or a skateboard ramp,
which is why they're designed like that. So you get
this massive gravity pool at the beginning, it built speed

(01:36):
and then you get the momentum to take it through
to that point, so it actually goes down to go up,
but it gets there faster than if it was a slide.

Speaker 1 (01:41):
Great.

Speaker 3 (01:42):
Why am I telling you this This beautiful study that
was published in Scientific Advances. It's all about our eye lashes.
And we've talked about eyelashes before when it comes to
helping protect from dirt, but we didn't really understand how
it protects us from water droplets. So when it's raining
and you're running in the rain, or if you're coming
out of a swimming pool, why is it your eyeballs
don't get wet and your eye lashes are really crucial

(02:04):
in this. And number one, it's because of this shape.
So if you look at the shape of your eyelashes,
they do this shape right. They go down and then
flick up at the end. And you can see it
really well in baby eyelashes because they have had these
gorgeous long that is the shape we're talking about, this
procrystochrone shape. Mathematically, we have the most perfectly shaped eyelashes
to protect us from water droplets externally, which we probably

(02:27):
didn't think about, right, you take our eyelashes for granted. Secondly,
they put eyelashes human eyelashes in a scanning electron microscope
and found that they're made up of these little plate
plates that stick on to each other. Think of like
the roof tiles on a roof, and they're designed to
stack onto each other. The water can't go backwards, it
can only drip down, so it drips away from rate.
It can't go back to your eye, so it's protecting

(02:49):
your eye in that way. And third they find that
your eyelashes are what we call hydrophobic, meaning that when
water touches it, it balls up and rolls straight off.
It doesn't wet or make a puddle. So you've got
these three separate things, massive engineering principles in one tiny eyelash,
and you go, huh amazing, like I don't think about
my eyelashes very often, and there's all this engineering or

(03:10):
athletics in it. But then you look at the beauty
procedures that we go through and basically we're hurting our
eyeballs and doing this. So mascare is naturally hydrophilic, meaning
that it causes water to make puddles. So water literally
will soak your eyeballs if you're wearing the scarbo. Number two.
Women tend to have their eyelashes curled. We have these

(03:30):
little horrific machines that, you know, the little squeezy things
that curl your eyelashes or you get them permanently permed,
because apparently have really upright eyelashes is attractive, terrible for
wicking water terrible. So all the things that we do
to protect our eyes from water, scientifically, the beauty standards
have got rid of them all, which I didn't even
think about before, but there you go. So eyelashes is.

Speaker 2 (03:53):
Fascinating because often your comment on what beautiful eyelashes you have,
what loving long eyelashes you have, and these sort of things.
But now you can say to people, what's stunning hydrophobic
properties your eyelashes?

Speaker 3 (04:03):
Here, isn't it?

Speaker 2 (04:05):
Fast setting?

Speaker 3 (04:06):
Bra Christachrone is our word of the day, and you
can say I love the prochostra home properties of your
eyelashes today.

Speaker 2 (04:13):
Or maybe you'll find another word. Tess. Thank you so much, Michelle,
love you to have you back with us for talk needs.

Speaker 1 (04:19):
For more from the Sunday session with Francesca Rudkin, listen
live to News Talks it B from nine am Sunday,
or follow the podcast on iHeartRadio