Nova (1974–…): Season 48, Episode 23 - Butterfly Blueprints - full transcript
Scientists are discovering the secrets of butterflies and using that knowledge to improve technology.
In the science of
the very small,
some ingenious inventors
are inspiring materials
with wondrous properties.
Sensitive to climate change.
They can act as a sentinel for
our interaction with the planet.
Brilliant color without paint.
What we see here is a close-up.
We see that the blue comes
from the background scales.
Protection from hazardous
chemicals and bacteria.
The word
"contaminated" on the glove
will turn from blue to red
when you touch a surface
that is contaminated.
Even an unsinkable metal.
As our ocean level
continue to go up,
in the future,
a lot of city will have
to be built on top of the ocean.
All thanks to the millions of
years of evolution
packed into the remarkable
world of butterflies and moths.
There's many problems that
humans haven't solved
that butterflies and moths
already have.
"Butterfly Blueprints,"
right now, on "NOVA."
♪♪
♪♪
Butterflies and moths.
Graceful and beautiful.
Their delicate wings seem
barely suitable for flight.
In spring and summer,
they appear in our skies,
flitting
and floating.
Their dazzling
colors and patterns
are among the most amazing
in the animal kingdom.
Some estimates put
the number of species
around 160,000,
and they thrive in nearly
every nook and cranny
of our planet.
If you go to
the northern latitudes,
you'll find butterflies.
If you go to the desert,
you'll find butterflies.
If you go to the rainforest,
you'll find butterflies
and moths.
Their variety and beauty
are testimony to
the power of evolution,
as are their
countless hidden features...
Some visible only with
the most powerful microscopes.
Today,
scientists around the world
are studying
these natural treasures.
Gorgeous.
Discovering secrets that
can be adapted
and applied to make
our world more sustainable.
They're so beautiful,
but we can learn a lot
by studying them.
As champions of evolution,
they've been at it for
tens of millions of years.
Butterflies emerged
around the same time as
flowering plants.
Throughout their long history,
they have diversified
and developed
amazing adaptations, like
powerful poisons, silk thread,
stationary flight,
transparent materials,
temperature regulation,
astonishing colors and patterns,
and defenses
against bacterial infections.
♪♪
They have so much to teach us.
But today, many species
are in danger of
extinction,
threatened by a warming world.
♪♪
And if we can
find ways to save them,
it's becoming clear that
we'll also be helping ourselves.
In North America,
an iconic species
is particularly vulnerable
to climate change
and habitat loss.
Delbert André Green Il,
a researcher at the University
of Michigan, Ann Arbor,
studies the complex life cycle
of the monarch butterfly.
One of the questions that
I get asked most often is,
why should we expend
so much resources
into this one
particular species,
this one butterfly?
What makes it so special?
What really
makes monarchs special is,
they can act as a sentinel
for our interaction with
the planet.
Their migration
covers an entire continent.
♪♪
That migration begins each fall
when millions of monarchs
take off from Canada
and the Northern United States
and head for Mexico,
where they remain
until the following spring.
It's a 3,000-mile
test of endurance
that lasts up to two months.
If we look at
this population size by
counting the number of monarchs
that make it to Mexico,
that number has been
declining pretty consistently
over the past two decades.
And that's,
we still consider worrisome.
Delbert believes the decline
can be used to gauge the level
of environmental change
that the butterflies encounter
on their journey.
If there aren't enough
nectaring flowers
along the migration route,
then monarchs
won't be able to power
the entire flight.
That's also going to be
impacted by climate
and by how we
change the landscape
through our own development or
agricultural practices.
In Mexico,
monarchs that survive the
journey gather together,
forming spectacular
wreaths of living color.
Snuggled close together,
they fall into a kind of
hibernation called diapause.
As their metabolism slows,
they suspend activity,
storing their energy
until the spring returns.
But during this time,
they are still vulnerable.
Diapause conditions have to be
almost perfect in order for them
to be able to survive
the winter.
If temperatures are changing
at the overwintering site,
then that's going to lead to
kind of this disturbance in,
potentially, diapause timing.
♪♪
During their diapause,
monarchs endure a very
sensitive and crucial time.
Diapause allows them to
slowly burn through
their fat stores.
So if it ends too early,
they're going to start
burning through their
fat stores more quickly,
and they're going to be
more susceptible to infection,
which will potentially
increase mortality
at the overwintering sites
before spring arrives,
and the temperatures
become warm enough
such that they can mate
and start to
fly back northwards.
By monitoring monarch
populations,
scientists can gain insight
into how a warming climate
can disrupt ecosystems,
threatening not only monarchs,
but other species, as well.
♪♪
Butterflies are
giving scientists like Delbert
a window into
our changing climate.
But that's only the
beginning of what studies
of these remarkable creatures
are revealing...
Particularly about
the structure of materials
at the nanoscopic scale.
Researchers
have been inspired by
incredible nanoscopic structures
in the wings and bodies
of butterflies,
enabling the creation
of innovative technologies
that may one day save lives
and even help combat
climate change.
Butterflies and moths have many
aspects of their morphology,
of their physiology,
that we could use
for bio-inspired design,
for sure.
I mean, there's many things,
many problems that humans
haven't solved
that butterflies
and moths already have.
♪♪
The use of butterfly and moth
features dates back
at least 5,000 years,
when the species
known as Bombyx mori
was first domesticated in China
for its ability to produce
a phenomenally resilient
and versatile material...
Silk.
♪♪
Because of
the importance of silk
to the Chinese imperial court,
the means of producing it
was a heavily guarded secret,
and its violators were punished,
even by death.
Today, of course,
the secret is out.
The whole process
starts with the hatching
of a miniscule egg
and the birth of
a caterpillar that measures
less than an eighth of an inch.
From its earliest days,
the Bombyx caterpillar
devours an enormous quantity
of mulberry leaves, plant matter
that it will eventually
convert into silk thread.
♪♪
After about a month of feeding,
the Bombyx caterpillar
will find a branch to climb,
where it will begin
metamorphosis
into its adult form.
For the next few days,
it will tirelessly repeat
the same figure-eight movement,
while secreting
a viscous filament, the silk,
eventually spinning up to a mile
of the thread into
a protective cocoon.
♪♪
Scientists have found that
the thread is mainly comprised
of just two proteins.
♪♪
Today, a whole new chapter
is opening in the story of silk.
Researchers at
the Tufts Silklab in Boston
have isolated
one of the proteins,
called fibroin,
and have created
an innovative material.
So, we end up with a solution
that is the suspension of
the fibroin molecules in water.
Once we have the solution,
this is our magical
starting material to do,
to do many, many things.
And so, and so the key is
that you have these proteins
that are floating in water,
and you remove water
as the solvent
and you have
two proteins come together
in many, many different formats.
Then you get different outcomes
of materials.
To the scientists,
silk is an incredibly versatile,
environmentally friendly
material.
What begins as
a colorless liquid...
This gel-like solution...
Can be either
flexible and soluble
or as tough as Kevlar.
Luciana d'Amone is exploring
medical applications.
Fibroin has an advantage
over synthetic materials
like plastics
because it's compatible with
the human body.
Oh, so this is the...
net.
Net, so these are very nice.
Yeah, but as soon as I
stretch them, they are,
are breaking down.
This is going to be nice
for, like,
a Band-Aid-type application
or a reconfigurable,
so these are very, very pretty.
Yeah, the idea would be to
mix the drug together
with a solution
and then control the release
of the drug on
a higher surface area,
just stretching the net.
Yeah.
The attributes,
the functional attributes
that silk has
that, that give value to some of
the applications of the silk,
is the fact that
silk can be implanted
without an inflammatory response
in the human body.
That it can, it can be eaten,
it can be consumed.
In the lab, they are finding
that the fibroin material
can be made to
be rigid and tough
or flexible, like a film,
making it an ideal material
as an implant
in reconstructive surgery.
If you take this material
and you know that you can
mechanically shape it
with the tools
that you commonly use
in a mechanic's shop,
then what you can do is,
you can generate small screws.
The screws made of fibroin
are similar to
the metal screws currently used
to reconstruct bones.
They can also deliver
human growth factor compounds
to help bones knit together.
So these are the worlds
that come together:
the mechanical properties
and the medical properties,
in a material that integrates
with, with living tissue.
In liquid form,
the fibroin in silk
is also being combined
with chemicals that react
in the presence of
bacteriological or
viral threats.
The result is an ink
that can change color
when exposed to
dangerous substances
in the environment.
All of the inks that are here
on the tapestry react,
react to the environment,
react to the environment
around it.
And so when you,
when there is a change
in the environment around it,
they will change
color accordingly.
♪♪
This fabric is of
particular interest
for making protective gear
for workers operating
where they might be exposed
to dangerous substances.
So these types of inks
are very interesting
to turn objects into,
into sensing objects.
If you print a word
with these inks
onto the surface of
personal protection equipment,
so, like, a glove here,
that word will, will
sense the environment around it.
In this case,
the word "contaminated"
on the glove
will turn from blue to red
when you touch a surface
that is contaminated.
The caterpillar
that produces silk
is only one stage in
the butterfly's
unique life cycle.
In all, it moves through
four distinct phases:
egg,
caterpillar,
chrysalis,
and adult.
The butterfly extracts itself
from its chrysalis,
dazed and fragile...
unfolding its wings and its body
with a cloth-like rustling.
When it emerges
from its chrysalis,
the adult has been
completely transformed
into one of the most delicate
and graceful creatures
in nature.
And, of course,
the vivid and iridescent
colors and patterns
of butterfly wings are
their most striking feature...
Nowhere seen more brilliantly
than in the male
of the morpho species
of the tropical rainforest.
In flight, its wings
seem to give off blue flashes
that are hard to miss,
even in the densest forest.
Serge Berthier,
a research physicist
at the Paris Institute of
Nanosciences,
talks about the wings'
unique properties.
Each species presents a
slightly different blue
and has a slightly
different wing beat,
and then variations of colors
that we see here:
a phenomenon of iridescence
where the color varies
in flight.
It's part of
the code of communication
between males and females.
It's an impressive adaptation
to the problem of finding
a mate in the forest,
but it comes with a problem.
What is so visible
to the female butterfly
is also noticeable
to hungry birds.
The male has to find a way
to parry this,
that is, being very visible
while not getting caught
by the first predator
that comes along.
The genius of this butterfly,
like many others,
is that it does not
fly straight.
As it flits through the forest
blinking blue,
it follows an
unpredictable zig-zag path,
making it hard to track.
So, you have a dotted line
zig-zagging like that,
which makes it almost impossible
for a bird to calculate
its trajectory
and snap it up in flight.
It's the morpho's
iridescent blue
that intrigues Serge and the
other researchers the most.
They want to understand
how nature produces a color
that looks so... unnatural.
What we see here is
a close-up of this wing.
We see that the blue
comes from
the background scales.
And there are scales here that
clog the joints on top of them.
These are covering scales,
and they are transparent...
You can see through them.
The morpho uses
a very peculiar way
to generate color.
It is a structural color,
which is intrinsically different
from a pigment color.
This is in contrast to
regular pigment.
Pigment are like
granules of pigment
that are inside of the cells
that give something
a yellow or a red or a,
or a green color.
The pigment color results from
the partial reflection of
daylight.
When a pigment reflects
a red color, for instance,
it means it has absorbed
all the other colors.
But then there's this other
type of coloration
that's actually not
caused by a pigment.
The structures that produce
the color of the morpho
are visible
under the microscope.
The wings show a regular pattern
of raised surfaces,
each one just one ten-millionth
of a meter in size.
It's the size of
these structures
that produces
the wings' iridescence.
It's caused by
little bumps, or, or...
Rugosities, they call them,
or little deviations
in the smoothness
of the insect's skin.
And when light
bounces off of that,
our eyes perceive it
as being a metallic,
or shiny, or iridescent color.
The blue of the morpho's wing
is not due to pigmentation,
but is generated by the
structure of the wing itself.
When light strikes the wing
at certain angles,
its nanoscale feature
selects only
the blue frequencies,
which are reflected,
resulting in an iridescent,
metallic appearance.
♪♪
The surprising new insight
into structural color
has inspired researchers
to control light and
produce color
without chemicals or paint
in all sorts of other materials.
At the Institute of Optics
at the University of Rochester
in the United States,
Chunlei Guo has succeeded
in creating such structures.
Inspired by this
morpho butterfly,
so we actually can also
imprint some of these
tiny micro, nanostructures
onto a material surface
and give them
very unique properties.
Using an infrared laser with
very short bursts of light,
they are able to
sculpt nano-sized structures,
measured in billionths
of a meter, into metals.
This incredible method of
creating various colors
on surfaces
has not only allowed
the researchers
to reproduce the color
of the butterfly's wings,
it also enables them
to create a highly
light-absorbing material
that could be called
absolute black.
Colored metal actually
will selectively absorb
a certain range of color,
but reflect other colors
so that it give you
a certain colored appearance.
So we create this technology,
so the black metal
actually will indistinguishly
absorb
all colors of, of the spectrum,
therefore it's, appear
pitch-black.
These discoveries
have the potential to
revolutionize solar power.
Chunlei's team found that
applying these nanostructures
to a solar panel
improved its efficiency by 130%.
The nanostructures
allow the panel to absorb
almost the entire
light spectrum,
minimizing loss of energy
due to reflection.
♪♪
As well as
transforming solar power,
inspiration from butterfly wings
could lead to other innovations.
Well, I mean, butterfly
and moth wings
serve multiple purposes, right?
Primarily, they're for flight.
But then, the coloration and
patterns that are on the wings
are a signaling.
Sometimes it's
signaling to each other,
males signaling to other males,
or males signaling to females
that's the same species.
Sometimes the signal
is actually for a predator.
In nature, color
plays a vital role
in both reproduction
and survival.
♪♪
Through either pigment
or structural color,
butterfly wings
often create complex patterns
that entomologists
suspect are meant to
send signals not to mates,
but to predators.
And in some cases,
present uncanny copies of
similar colors and patterns
found in other living things.
Often, the butterflies and moths
that you see are orange
or orange, yellow, and black.
It's a signal that
these moths or butterflies
are distasteful,
and presumably
birds only have to learn
one big kind of color pattern.
Orange, black, yellow: avoid.
In the plant and animal world,
orange, yellow, and black
are sometimes associated
with poison.
And some butterflies
seem to rely on those colors
to discourage birds
from eating them.
And these two look
really similar.
These are the monarch
and the viceroy.
The monarch and the viceroy
are easy to distinguish
because the viceroy
has this additional
kind of line of dark color by
the base of its wings.
This is a distasteful
monarch butterfly
that birds learn to avoid.
And the viceroy mimics
the monarch's coloration
presumably so that
it also can be protected
and it doesn't get eaten by
birds like, like blue jays.
Butterflies use a variety of
defense mechanisms.
Although some boldly
wear the signs of toxicity,
others prefer to pass unseen.
They melt into
the surrounding colors
of their natural environment.
For example, the Greta oto,
also known as
a glasswing butterfly,
relies on a double defense:
displaying some warning colors
while most of the wing
is almost totally transparent...
A most unusual adaptation.
The wings' surfaces have
scarcely any reflectivity.
Even glass and
other human-made materials
reflect some light.
But not this butterfly wing,
which makes it extremely
interesting to scientists.
Researchers at the
Karlsruhe Institute
of Technology in Germany
are studying
the unusual properties
of transparent-type wings
like the Greta oto's.
What we see on top
are these nanostructures here,
nano pillars,
which have random heights.
And also the distance
between the nano pillars
is a little bit random.
So they're
not regularly arranged.
And this randomness is important
for the anti-reflective
properties of the butterfly.
♪♪
This is where the secret of
the high transparency lies:
the random distribution
and size of
these conical nanometric pillars
create an anti-reflective layer,
allowing light rays,
even the most grazing,
to pass through the wing
without being
dispersed or reflected.
This anti-reflective property
is interesting for
different types of applications,
like smartphones, for instance.
In the summer,
when the sun is shining,
it's hard to read
and it would be nice
to have an
anti-reflective screen.
And also for solar cells.
It would be interesting
to have less reflection
and have more collection
of the solar energy.
These researchers create
a plastic film on which
they print nanostructures
in imitation of those
in the crystalline-type wing.
Their goal is to create
anti-reflective materials
that are highly transparent.
The nanostructures of the wings
offer other properties,
such as the ability to
repel water,
known as hydrophobicity.
Staying dry is a matter of
life and death for butterflies.
Mist and rain
would quickly ground them
if they weren't waterproof.
A butterfly must not get wet.
If the wings were wet
and they touched each other,
they would stick together,
and the butterfly would die.
So a butterfly wing is
super-hydrophobic.
That is, the wing doesn't get
wet... water forms beads.
And then the beads
roll off, cleaning the wing of
all of the dust and dirt
it picks up along the way.
Thanks to its nanometric
structures,
the morpho's wing doesn't just
rid itself of water drops,
it breaks them down into
a multitude of smaller drops
that flow more easily
off the surface.
In his Rochester lab,
Chunlei Guo is exploring
possible engineering
applications for this extremely
hydrophobic material.
In one of his experiments,
he starts by laser-etching
a metallic surface with a
nanoscale pattern
inspired by the morpho wing.
He's hoping to create the same
water-repelling effect.
♪♪
When he drops water on the
surface he has created,
it is totally repelled.
The experiment is a success.
Water drops are not only
repelled,
they bounce back.
With this material,
Chunlei's team seems to have
created an unsinkable metal.
And what we did was, we actually
utilized in,
build a metallic assembly
with a super-hydrophobic
surface,
so that the hydrophobic surface,
they are facing each other.
And if you put this
metallic assembly inside water,
and because the inside of the
assembly is super-hydrophobic,
so that it will push the water
out and will prevent the water
squeezing into the
metallic assembly,
and the air trapped inside
will keep
the metallic assembly afloat.
Fabricating a ship's hull
using this design would have
an obvious benefit.
But Chunlei believes
it could also help us adapt
to climate change.
And as our ocean level
continue to
go up in the future,
a lot of city will have to be
built on top of the ocean.
And if we can deploy this
unsinkable metal
for construction of the floating
city, then the city
will never sink.
♪♪
Who could have imagined
that one day a ship...
Or even a whole city...
Might rest on
a butterfly's wing?
In California,
researchers work on combining
transparency
and the opposite of
hydrophobicity...
Extreme water absorption.
What's at stake is not
rising water, but glaucoma,
a group of eye conditions
that can cause blindness.
Radwanul Hasan Siddique
at Caltech is working to create
a tiny implant that would work
inside the eye to help detect
this devastating condition.
So, in our lab,
we make an optical implant
for continuously measure
the eye pressure
for glaucoma progression
measurement.
♪♪
Glaucoma is a condition
that damages the optic nerve,
most often caused by rising
internal pressure in the eye.
Today, an implant could provide
easy access
and constant monitoring
for a patient at risk.
But of course, anything inside
the eye needs to be transparent,
especially an
artificial implant.
Glass has around eight to ten
percent reflection.
And that reflection basically,
you can see a glare, right?
So if you see in the windows
or glass at some angle,
you can see glare because of
the reflection of the light.
But this glasswing butterfly,
although it's glass-like, but it
doesn't have any reflection,
or almost no reflection.
For Radwanul,
an implant in the eye
cannot be water-repellent
like the butterfly wing.
He needs to engineer something
different.
The implant is going to be
in the inside of your eye
in the aqueous humor,
which is a fluid.
So if it's, repels water,
then it's hard to implant,
and it won't survive there.
So in our case, we need
basically an opposite property,
which is super-hydrophilic.
♪♪
To make his implant,
Radwanul blends two chemical
compounds at very high speed.
Their combination creates
nanostructures like those of
the glasswing butterfly
out of a hydrophilic material
that patients' eyes
can tolerate.
These randomly distributed
dome-shaped nanostructures
conserve the transparent
properties of their model.
Because the gaps between them
are so narrow,
bacteria cannot get a grip
on the surface,
reducing the risk of infection.
Once we introduce
a nanostructure like the
glasswing-inspired
nanostructures on the implant,
it shows better performance,
has a better optical readout,
and also, it doesn't show
any anti-fouling,
any fouling properties, so...
Which means no tissue
are encapsulating,
no, no bacteria are sitting,
and we may take a measurement
over a year inside a rabbit eye
without seeing any kind of
fouling.
♪♪
Not all butterfly wings
are visually arresting.
The nanostructures in wings
are not only involved in color,
transparency,
or tricking predators.
Some of them serve to provide
direct metabolic benefits
for survival.
♪♪
Like all insects,
butterflies and moths
are cold-blooded.
No butterfly can take off
without a minimum of sunlight
to heat its body.
Dark-winged butterflies absorb
the heat of the sun
more readily and seem to have
an advantage over those
with lighter-colored wings.
♪♪
It might seem that
a white-winged butterfly,
like the cabbage white
butterfly,
would be operating
at a huge disadvantage.
And yet, in the early morning,
even on cloudy days,
it is one of the first arrivals
to gather nectar in
flower fields.
How does it manage it?
♪♪
At the Paris Institute
of Nanosciences,
Serge Berthier is interested in
this phenomenon.
So the white butterflies
cannot directly absorb light
through the wings
because they're white,
and reflect all the energy.
What they do when they need
to warm up is use their wings
as concentrators
before taking off.
They place themselves
facing the sun,
then open and close their wings
like this.
As it's very reflective,
it sends a lot of light,
and concentrates the light
on its back, the thorax,
where the wings'
abductor muscles are located.
So when the wings concentrate
the light,
the thorax will absorb
all this energy.
The reflective white coloration
acts as a mirror
to concentrate heat onto
the animal's body.
In the tiniest details,
Serge Berthier can verify the
way heat is sent to the thorax.
As with all scales, we see
a network of striations,
but what's particular to the
cabbage white butterfly
is that there is a network
of counter-striations,
in this direction.
And small compartments
are formed inside.
The cabbage white's scales
contain tightly packed
ovoid-shaped granules,
like eggs in a carton.
They reflect the sun's rays,
but not in all directions.
They focus the light and heat
like a magnifying glass.
The butterfly then angles
its wings in a way that sends
the heat down to its back.
This is how the butterfly
warms up.
The butterfly just has to
open and close its wings
to regulate its temperature.
In fact, it's the master
of its own temperature.
♪♪
Finding new ways to concentrate
sunlight is important
for humans, too, in the search
for cheap and efficient
replacements for fossil fuels.
In her lab at the
University of Exeter,
Katie Shanks is adapting
the cabbage white's
reflective nanostructures
to solar panels,
working to increase their output
while reducing their size.
So by looking at the wings
of the cabbage white butterfly,
we can actually
reduce the weight
a very significant amount.
So in initial studies,
we've been able to improve
the power-to-weight ratio
by 17 times,
which is, is a massive amount.
And what I'm specifically
looking at is using those
very lightweight nanostructured
wings to make our own
very compact advanced
solar panel
built into any materials.
♪♪
Today, by combining the
properties of the glasswing
and cabbage white wings,
researchers are hoping
to develop a new generation
of solar panels.
So the glasswing butterfly
would be for the surface,
the entrance aperture.
And the cabbage white butterfly
would be for the side walls,
just before the solar cells.
And overall, that means we get
this kind of
increased power output
from all the solar cells,
but not using as much
PV material.
And you can also make it
a lot smaller and lightweight,
as well.
I mean, all of the butterflies
and lots of other things
in nature have had to do this,
you know,
as, as they've developed,
they've evolved,
and they've tweaked themselves
to suit their surroundings.
And I think we're now realizing
we have to do the same
in terms of tweaking our,
you know, energy demands
and our uses and our materials
that we use to kind of make sure
we are also sustainable
and surviving,
just as the butterflies are.
♪♪
It's remarkable that butterfly
wings can offer protection
from predators and rain,
and also capture the sun's rays
to warm up.
But that's not the end
of their impressive biology.
Their delicate antennae serve
as highly sensitive
chemical-detecting noses.
They have those little pits
that are inside of,
are along the length
of the antennae.
And those sensory pits
are basically capable of,
of detecting kind of
chemical compounds,
and basically olfaction,
or, or smelling.
♪♪
The antennae of the male Bombyx
are loaded with a multitude
of microscopic sensing organs,
known as sensilla, that vibrate
at very high frequency.
They can home in on the one
kind of pheromone molecule
they are looking for,
among all the other ones
in suspension in the atmosphere.
In fact, some researchers
believe that the silk moths
have some of the most
highly developed senses of smell
in the living world.
Males are thus able to detect
a female
from over six miles away,
an extraordinary feat
which scientists working on
the detection of explosives
or toxic gases
would love to harness.
♪♪
Valérie Keller and her team
are part of a program
for protecting
civilian populations.
You can see on the antennas
that the sensilla's structure
is kind of like tiny sticks.
We drew inspiration from them.
In fact, we are trying to do
bio-inspiration by making
a synthesis in the lab
that enables us
to duplicate this architecture
you see in nature.
Mechanically duplicating
the anatomical genius of the
Bombyx is not an easy task.
Valérie Keller's team
is creating a forest of sensilla
via a chemical reaction
on a titanium base.
The result is a forest-like
arrangement
of titanium dioxide nanotubes.
If a chemical molecule
in the air
attaches to the nanotubes,
its weight changes the vibration
frequency of the forest,
slowing them down in a way
that can set off an alarm.
TNT, sarin gas,
and other toxic chemicals
all have their own weights.
Nanotubes are programmed
to react to those signals
to trigger alarms.
At the French-German Research
Institute of Saint-Louis,
Denis Spitzer foresees a
big future for these detectors.
We can come up with stationary
detectors, but then we can go on
basing them on the butterfly,
that is,
we can start to make
the detectors fly,
and the idea came to us
to implant these detectors
on drones, so that the military
or civil security people
can detect dangerous compounds.
It could be war toxins,
or sarin gas, or other extremely
dangerous compounds.
Because when the person feels
the first symptoms of gas like
that, it is already too late.
Drone surveillance
of large urban areas
could save major populations
from terrorist gas attacks.
♪♪
The amazing evolutionary tricks
of butterflies and moths
are not limited to their wings,
or their antennae.
Unlike many insects,
they don't have what might be
recognized as a mouth.
Most of the butterflies
and moths that we, we think of
have a sucking mouth part,
like a proboscis,
that is kind of coiled up,
that kind of is like a straw.
And it kind of extends outwards
with this cranial sucking pump,
and it sucks up
nectar from flowers.
♪♪
Many butterflies live
only for a few weeks.
But one, called Heliconius,
stands out,
with a lifespan closer to
six months.
♪♪
This relatively long-lived
butterfly fascinates
Adriana Briscoe
and Larry Gilbert.
One of the ways we think
they can live so long
is because they have changed
their diet.
They live a long time because
they have developed this ability
to harvest pollen.
♪♪
While most butterflies
feed mainly on nectar,
Heliconius adds pollen
to its diet.
The pollen sticks to the entire
length of its proboscis.
The pollen might keep
the butterfly healthy,
but Adriana has found
a possible medical application
derived from the way
Heliconius digests the nutrient.
She's collaborating with
chemist Rachel Martin.
This is the part of the
proboscis
where fluids can go in...
Mm-hmm.
And they can also go out.
I was really fascinated
to find out that
it acts like a sponge.
I was kind of always
picturing this being
like a giant drinking straw.
Oh, yeah, no.
You can see that there
are these ridges
shown in green,
and those are perfect grooves
for pollen to get stuck in.
When the butterflies
probe the flower,
and the pollen grains start to
get stuck in those grooves,
the butterflies then release
saliva from the tip
of their proboscis,
and that starts to glue things
together.
It makes sense that
the butterfly would have enzymes
that are really optimized
for getting into those little
nooks and crannies,
and digesting the protein,
because pollen is about
20% protein, so it's a...
That's a lot.
It is a lot.
The Heliconius's long life
might be explained in part
by this intake
of high-protein pollen,
which it actually digests
on the outside of its proboscis
thanks to a very particular
type of enzyme.
That enzyme is known
as cocoonase,
because it was originally
discovered in silk moths.
Silk moths have one version
of this enzyme which they use
to digest their silk cocoons
so they can escape.
If that enzyme
is not functioning,
they die in their cocoons.
By extracting this cocoonase
enzyme to reproduce
its dissolving properties
on a large scale,
Adriana hopes to alleviate
potentially serious medical
conditions like blood clots.
Blood clots are very common
in the United States.
It turns out you can take
cocoonase, and in a test tube,
you can mix it up
with a blood clot
and it'll break it down
into its component parts.
♪♪
Like the silk protein fibroin,
the cocoonase protein is also
compatible with human biology.
And the longevity Heliconius
may glean from pollen shows
how tightly the evolution
of butterflies depends on
the plants they feed on.
Plants and butterflies have
mutual evolution.
From egg to chrysalis,
many butterfly species are born,
grow up, and metamorphose
on individual plant species
with which they are associated.
You sometimes have a species
of butterfly or moth
that is the only thing
that can pollinate
a particular, a particular
species of, of flower.
And so, these really tight
interactions mean that
if we lose one of those members
of this partnership,
then you often end up losing
both species.
♪♪
The fates of butterflies
and plants are forever linked,
to such a degree that we cannot
hope to preserve
butterflies without preserving
their ecosystems.
Today's climate change may have
very unfortunate consequences.
♪♪
Spring has come to Mexico,
signaling to the monarchs
the time to return.
But these butterflies,
who migrated south in the fall,
now have to fly back north.
♪♪
How will they know which way
to fly?
Christine Merlin keeps a small
group of monarchs for study.
Just want a cooperative one.
You know, cooperate with me.
That one is actually in the
process of laying an egg.
She wants to explore and
understand which specific genes
trigger the migration
and guide them on their way.
This one just did.
Okay, this one is getting ready.
Christine believes that changes
in the environment
trigger a response
in the migratory genes
of the monarchs,
a process known as epigenetics.
I'm not as good as my student.
So with each butterfly's egg,
she analyzes a range of genes
to discover which are involved
with the timing
of the monarchs' navigation
and which
with the direction they follow.
One of the best example
of epigenetic changes
that occur in, in
monarch migration
is that of the recalibration
of their sun-compass orientation
from southward in the fall
to northwards in, in the spring.
And...
We do believe that
epigenetic changes
are responsible for this switch
in flight orientation.
Migrating monarchs also use
magnetic fields to guide
their flight orientation.
To find genes that allow
monarchs to sense
the magnetic field,
Christine uses a Faraday cage
that blocks the outside
electromagnetic influences.
There, she generates her own
magnetic field
to test the reaction
of the monarchs' behavior.
We use a magnetic coil
to test the response
of monarch butterfly
to the reversal
of the inclination.
And when butterfly sense
and respond to this reversal,
they start flapping their wings
really strongly,
they have an active flight.
And once we reverse the
magnetic field back to normal,
then the behavioral responses
extinguishes itself.
♪♪
The evidence is in: monarchs
are genetically programmed
to align with the magnetic
field, and we can see them
flap their wings
when they sense it.
When the seasons change,
causing a change of temperature,
a change of the angle
of the sun,
as well as a change
in the daily sunshine duration,
the butterflies' genes
trigger a signal to migrate.
♪♪
When in Canada and the U.S.,
the onset of fall signals
departure.
♪♪
"Colder... go south!"
When in Mexico,
spring tells them, "Go north!"
Given the extent that monarchs
depend on temperature,
it's not surprising that
climate change
worries researchers like
Delbert,
who monitors monarch populations
in part to understand the risks
we all face.
In that way,
by studying monarchs' biology
very closely,
it indirectly tells us
our own impacts on their
environment that they cover.
So we want to watch what's
happening to them,
watch how they're being
impacted, such that we know then
how other species may
potentially being impacted,
because they're being impacted
by those same climate change.
♪♪
Well, butterflies and moths
are really a big part
of the whole ecosystem.
So, if we were to lose
a certain species,
or groups of species, like
butterflies and moths,
we'd lose pollinators, for sure,
but we'd also lose
an important diet for birds.
We'd lose an important diet
for other insects, like
dragonflies.
We'd lose important diet items
even for people.
Because there are people that
like to eat these, these
as food items.
So, it's a kind of
a cascading effect.
It's not just that you would
lose this one insect.
You would actually lose many
members of the community
to which it belongs.
And that's, I think, the thing
that we're, we're working
against.
♪♪
Butterflies and moths
are inspiring scientists
and engineers
to create remarkable inventions.
From the nanoscopic structures
on their wings
that create color
and transparency
to their ability to repel water
and fight infection,
they offer lessons
about what's possible
at the very smallest scale.
But they also present us
with a warning
about what's at stake if we fail
as stewards of this endlessly
inventive natural environment.
♪♪
the very small,
some ingenious inventors
are inspiring materials
with wondrous properties.
Sensitive to climate change.
They can act as a sentinel for
our interaction with the planet.
Brilliant color without paint.
What we see here is a close-up.
We see that the blue comes
from the background scales.
Protection from hazardous
chemicals and bacteria.
The word
"contaminated" on the glove
will turn from blue to red
when you touch a surface
that is contaminated.
Even an unsinkable metal.
As our ocean level
continue to go up,
in the future,
a lot of city will have
to be built on top of the ocean.
All thanks to the millions of
years of evolution
packed into the remarkable
world of butterflies and moths.
There's many problems that
humans haven't solved
that butterflies and moths
already have.
"Butterfly Blueprints,"
right now, on "NOVA."
♪♪
♪♪
Butterflies and moths.
Graceful and beautiful.
Their delicate wings seem
barely suitable for flight.
In spring and summer,
they appear in our skies,
flitting
and floating.
Their dazzling
colors and patterns
are among the most amazing
in the animal kingdom.
Some estimates put
the number of species
around 160,000,
and they thrive in nearly
every nook and cranny
of our planet.
If you go to
the northern latitudes,
you'll find butterflies.
If you go to the desert,
you'll find butterflies.
If you go to the rainforest,
you'll find butterflies
and moths.
Their variety and beauty
are testimony to
the power of evolution,
as are their
countless hidden features...
Some visible only with
the most powerful microscopes.
Today,
scientists around the world
are studying
these natural treasures.
Gorgeous.
Discovering secrets that
can be adapted
and applied to make
our world more sustainable.
They're so beautiful,
but we can learn a lot
by studying them.
As champions of evolution,
they've been at it for
tens of millions of years.
Butterflies emerged
around the same time as
flowering plants.
Throughout their long history,
they have diversified
and developed
amazing adaptations, like
powerful poisons, silk thread,
stationary flight,
transparent materials,
temperature regulation,
astonishing colors and patterns,
and defenses
against bacterial infections.
♪♪
They have so much to teach us.
But today, many species
are in danger of
extinction,
threatened by a warming world.
♪♪
And if we can
find ways to save them,
it's becoming clear that
we'll also be helping ourselves.
In North America,
an iconic species
is particularly vulnerable
to climate change
and habitat loss.
Delbert André Green Il,
a researcher at the University
of Michigan, Ann Arbor,
studies the complex life cycle
of the monarch butterfly.
One of the questions that
I get asked most often is,
why should we expend
so much resources
into this one
particular species,
this one butterfly?
What makes it so special?
What really
makes monarchs special is,
they can act as a sentinel
for our interaction with
the planet.
Their migration
covers an entire continent.
♪♪
That migration begins each fall
when millions of monarchs
take off from Canada
and the Northern United States
and head for Mexico,
where they remain
until the following spring.
It's a 3,000-mile
test of endurance
that lasts up to two months.
If we look at
this population size by
counting the number of monarchs
that make it to Mexico,
that number has been
declining pretty consistently
over the past two decades.
And that's,
we still consider worrisome.
Delbert believes the decline
can be used to gauge the level
of environmental change
that the butterflies encounter
on their journey.
If there aren't enough
nectaring flowers
along the migration route,
then monarchs
won't be able to power
the entire flight.
That's also going to be
impacted by climate
and by how we
change the landscape
through our own development or
agricultural practices.
In Mexico,
monarchs that survive the
journey gather together,
forming spectacular
wreaths of living color.
Snuggled close together,
they fall into a kind of
hibernation called diapause.
As their metabolism slows,
they suspend activity,
storing their energy
until the spring returns.
But during this time,
they are still vulnerable.
Diapause conditions have to be
almost perfect in order for them
to be able to survive
the winter.
If temperatures are changing
at the overwintering site,
then that's going to lead to
kind of this disturbance in,
potentially, diapause timing.
♪♪
During their diapause,
monarchs endure a very
sensitive and crucial time.
Diapause allows them to
slowly burn through
their fat stores.
So if it ends too early,
they're going to start
burning through their
fat stores more quickly,
and they're going to be
more susceptible to infection,
which will potentially
increase mortality
at the overwintering sites
before spring arrives,
and the temperatures
become warm enough
such that they can mate
and start to
fly back northwards.
By monitoring monarch
populations,
scientists can gain insight
into how a warming climate
can disrupt ecosystems,
threatening not only monarchs,
but other species, as well.
♪♪
Butterflies are
giving scientists like Delbert
a window into
our changing climate.
But that's only the
beginning of what studies
of these remarkable creatures
are revealing...
Particularly about
the structure of materials
at the nanoscopic scale.
Researchers
have been inspired by
incredible nanoscopic structures
in the wings and bodies
of butterflies,
enabling the creation
of innovative technologies
that may one day save lives
and even help combat
climate change.
Butterflies and moths have many
aspects of their morphology,
of their physiology,
that we could use
for bio-inspired design,
for sure.
I mean, there's many things,
many problems that humans
haven't solved
that butterflies
and moths already have.
♪♪
The use of butterfly and moth
features dates back
at least 5,000 years,
when the species
known as Bombyx mori
was first domesticated in China
for its ability to produce
a phenomenally resilient
and versatile material...
Silk.
♪♪
Because of
the importance of silk
to the Chinese imperial court,
the means of producing it
was a heavily guarded secret,
and its violators were punished,
even by death.
Today, of course,
the secret is out.
The whole process
starts with the hatching
of a miniscule egg
and the birth of
a caterpillar that measures
less than an eighth of an inch.
From its earliest days,
the Bombyx caterpillar
devours an enormous quantity
of mulberry leaves, plant matter
that it will eventually
convert into silk thread.
♪♪
After about a month of feeding,
the Bombyx caterpillar
will find a branch to climb,
where it will begin
metamorphosis
into its adult form.
For the next few days,
it will tirelessly repeat
the same figure-eight movement,
while secreting
a viscous filament, the silk,
eventually spinning up to a mile
of the thread into
a protective cocoon.
♪♪
Scientists have found that
the thread is mainly comprised
of just two proteins.
♪♪
Today, a whole new chapter
is opening in the story of silk.
Researchers at
the Tufts Silklab in Boston
have isolated
one of the proteins,
called fibroin,
and have created
an innovative material.
So, we end up with a solution
that is the suspension of
the fibroin molecules in water.
Once we have the solution,
this is our magical
starting material to do,
to do many, many things.
And so, and so the key is
that you have these proteins
that are floating in water,
and you remove water
as the solvent
and you have
two proteins come together
in many, many different formats.
Then you get different outcomes
of materials.
To the scientists,
silk is an incredibly versatile,
environmentally friendly
material.
What begins as
a colorless liquid...
This gel-like solution...
Can be either
flexible and soluble
or as tough as Kevlar.
Luciana d'Amone is exploring
medical applications.
Fibroin has an advantage
over synthetic materials
like plastics
because it's compatible with
the human body.
Oh, so this is the...
net.
Net, so these are very nice.
Yeah, but as soon as I
stretch them, they are,
are breaking down.
This is going to be nice
for, like,
a Band-Aid-type application
or a reconfigurable,
so these are very, very pretty.
Yeah, the idea would be to
mix the drug together
with a solution
and then control the release
of the drug on
a higher surface area,
just stretching the net.
Yeah.
The attributes,
the functional attributes
that silk has
that, that give value to some of
the applications of the silk,
is the fact that
silk can be implanted
without an inflammatory response
in the human body.
That it can, it can be eaten,
it can be consumed.
In the lab, they are finding
that the fibroin material
can be made to
be rigid and tough
or flexible, like a film,
making it an ideal material
as an implant
in reconstructive surgery.
If you take this material
and you know that you can
mechanically shape it
with the tools
that you commonly use
in a mechanic's shop,
then what you can do is,
you can generate small screws.
The screws made of fibroin
are similar to
the metal screws currently used
to reconstruct bones.
They can also deliver
human growth factor compounds
to help bones knit together.
So these are the worlds
that come together:
the mechanical properties
and the medical properties,
in a material that integrates
with, with living tissue.
In liquid form,
the fibroin in silk
is also being combined
with chemicals that react
in the presence of
bacteriological or
viral threats.
The result is an ink
that can change color
when exposed to
dangerous substances
in the environment.
All of the inks that are here
on the tapestry react,
react to the environment,
react to the environment
around it.
And so when you,
when there is a change
in the environment around it,
they will change
color accordingly.
♪♪
This fabric is of
particular interest
for making protective gear
for workers operating
where they might be exposed
to dangerous substances.
So these types of inks
are very interesting
to turn objects into,
into sensing objects.
If you print a word
with these inks
onto the surface of
personal protection equipment,
so, like, a glove here,
that word will, will
sense the environment around it.
In this case,
the word "contaminated"
on the glove
will turn from blue to red
when you touch a surface
that is contaminated.
The caterpillar
that produces silk
is only one stage in
the butterfly's
unique life cycle.
In all, it moves through
four distinct phases:
egg,
caterpillar,
chrysalis,
and adult.
The butterfly extracts itself
from its chrysalis,
dazed and fragile...
unfolding its wings and its body
with a cloth-like rustling.
When it emerges
from its chrysalis,
the adult has been
completely transformed
into one of the most delicate
and graceful creatures
in nature.
And, of course,
the vivid and iridescent
colors and patterns
of butterfly wings are
their most striking feature...
Nowhere seen more brilliantly
than in the male
of the morpho species
of the tropical rainforest.
In flight, its wings
seem to give off blue flashes
that are hard to miss,
even in the densest forest.
Serge Berthier,
a research physicist
at the Paris Institute of
Nanosciences,
talks about the wings'
unique properties.
Each species presents a
slightly different blue
and has a slightly
different wing beat,
and then variations of colors
that we see here:
a phenomenon of iridescence
where the color varies
in flight.
It's part of
the code of communication
between males and females.
It's an impressive adaptation
to the problem of finding
a mate in the forest,
but it comes with a problem.
What is so visible
to the female butterfly
is also noticeable
to hungry birds.
The male has to find a way
to parry this,
that is, being very visible
while not getting caught
by the first predator
that comes along.
The genius of this butterfly,
like many others,
is that it does not
fly straight.
As it flits through the forest
blinking blue,
it follows an
unpredictable zig-zag path,
making it hard to track.
So, you have a dotted line
zig-zagging like that,
which makes it almost impossible
for a bird to calculate
its trajectory
and snap it up in flight.
It's the morpho's
iridescent blue
that intrigues Serge and the
other researchers the most.
They want to understand
how nature produces a color
that looks so... unnatural.
What we see here is
a close-up of this wing.
We see that the blue
comes from
the background scales.
And there are scales here that
clog the joints on top of them.
These are covering scales,
and they are transparent...
You can see through them.
The morpho uses
a very peculiar way
to generate color.
It is a structural color,
which is intrinsically different
from a pigment color.
This is in contrast to
regular pigment.
Pigment are like
granules of pigment
that are inside of the cells
that give something
a yellow or a red or a,
or a green color.
The pigment color results from
the partial reflection of
daylight.
When a pigment reflects
a red color, for instance,
it means it has absorbed
all the other colors.
But then there's this other
type of coloration
that's actually not
caused by a pigment.
The structures that produce
the color of the morpho
are visible
under the microscope.
The wings show a regular pattern
of raised surfaces,
each one just one ten-millionth
of a meter in size.
It's the size of
these structures
that produces
the wings' iridescence.
It's caused by
little bumps, or, or...
Rugosities, they call them,
or little deviations
in the smoothness
of the insect's skin.
And when light
bounces off of that,
our eyes perceive it
as being a metallic,
or shiny, or iridescent color.
The blue of the morpho's wing
is not due to pigmentation,
but is generated by the
structure of the wing itself.
When light strikes the wing
at certain angles,
its nanoscale feature
selects only
the blue frequencies,
which are reflected,
resulting in an iridescent,
metallic appearance.
♪♪
The surprising new insight
into structural color
has inspired researchers
to control light and
produce color
without chemicals or paint
in all sorts of other materials.
At the Institute of Optics
at the University of Rochester
in the United States,
Chunlei Guo has succeeded
in creating such structures.
Inspired by this
morpho butterfly,
so we actually can also
imprint some of these
tiny micro, nanostructures
onto a material surface
and give them
very unique properties.
Using an infrared laser with
very short bursts of light,
they are able to
sculpt nano-sized structures,
measured in billionths
of a meter, into metals.
This incredible method of
creating various colors
on surfaces
has not only allowed
the researchers
to reproduce the color
of the butterfly's wings,
it also enables them
to create a highly
light-absorbing material
that could be called
absolute black.
Colored metal actually
will selectively absorb
a certain range of color,
but reflect other colors
so that it give you
a certain colored appearance.
So we create this technology,
so the black metal
actually will indistinguishly
absorb
all colors of, of the spectrum,
therefore it's, appear
pitch-black.
These discoveries
have the potential to
revolutionize solar power.
Chunlei's team found that
applying these nanostructures
to a solar panel
improved its efficiency by 130%.
The nanostructures
allow the panel to absorb
almost the entire
light spectrum,
minimizing loss of energy
due to reflection.
♪♪
As well as
transforming solar power,
inspiration from butterfly wings
could lead to other innovations.
Well, I mean, butterfly
and moth wings
serve multiple purposes, right?
Primarily, they're for flight.
But then, the coloration and
patterns that are on the wings
are a signaling.
Sometimes it's
signaling to each other,
males signaling to other males,
or males signaling to females
that's the same species.
Sometimes the signal
is actually for a predator.
In nature, color
plays a vital role
in both reproduction
and survival.
♪♪
Through either pigment
or structural color,
butterfly wings
often create complex patterns
that entomologists
suspect are meant to
send signals not to mates,
but to predators.
And in some cases,
present uncanny copies of
similar colors and patterns
found in other living things.
Often, the butterflies and moths
that you see are orange
or orange, yellow, and black.
It's a signal that
these moths or butterflies
are distasteful,
and presumably
birds only have to learn
one big kind of color pattern.
Orange, black, yellow: avoid.
In the plant and animal world,
orange, yellow, and black
are sometimes associated
with poison.
And some butterflies
seem to rely on those colors
to discourage birds
from eating them.
And these two look
really similar.
These are the monarch
and the viceroy.
The monarch and the viceroy
are easy to distinguish
because the viceroy
has this additional
kind of line of dark color by
the base of its wings.
This is a distasteful
monarch butterfly
that birds learn to avoid.
And the viceroy mimics
the monarch's coloration
presumably so that
it also can be protected
and it doesn't get eaten by
birds like, like blue jays.
Butterflies use a variety of
defense mechanisms.
Although some boldly
wear the signs of toxicity,
others prefer to pass unseen.
They melt into
the surrounding colors
of their natural environment.
For example, the Greta oto,
also known as
a glasswing butterfly,
relies on a double defense:
displaying some warning colors
while most of the wing
is almost totally transparent...
A most unusual adaptation.
The wings' surfaces have
scarcely any reflectivity.
Even glass and
other human-made materials
reflect some light.
But not this butterfly wing,
which makes it extremely
interesting to scientists.
Researchers at the
Karlsruhe Institute
of Technology in Germany
are studying
the unusual properties
of transparent-type wings
like the Greta oto's.
What we see on top
are these nanostructures here,
nano pillars,
which have random heights.
And also the distance
between the nano pillars
is a little bit random.
So they're
not regularly arranged.
And this randomness is important
for the anti-reflective
properties of the butterfly.
♪♪
This is where the secret of
the high transparency lies:
the random distribution
and size of
these conical nanometric pillars
create an anti-reflective layer,
allowing light rays,
even the most grazing,
to pass through the wing
without being
dispersed or reflected.
This anti-reflective property
is interesting for
different types of applications,
like smartphones, for instance.
In the summer,
when the sun is shining,
it's hard to read
and it would be nice
to have an
anti-reflective screen.
And also for solar cells.
It would be interesting
to have less reflection
and have more collection
of the solar energy.
These researchers create
a plastic film on which
they print nanostructures
in imitation of those
in the crystalline-type wing.
Their goal is to create
anti-reflective materials
that are highly transparent.
The nanostructures of the wings
offer other properties,
such as the ability to
repel water,
known as hydrophobicity.
Staying dry is a matter of
life and death for butterflies.
Mist and rain
would quickly ground them
if they weren't waterproof.
A butterfly must not get wet.
If the wings were wet
and they touched each other,
they would stick together,
and the butterfly would die.
So a butterfly wing is
super-hydrophobic.
That is, the wing doesn't get
wet... water forms beads.
And then the beads
roll off, cleaning the wing of
all of the dust and dirt
it picks up along the way.
Thanks to its nanometric
structures,
the morpho's wing doesn't just
rid itself of water drops,
it breaks them down into
a multitude of smaller drops
that flow more easily
off the surface.
In his Rochester lab,
Chunlei Guo is exploring
possible engineering
applications for this extremely
hydrophobic material.
In one of his experiments,
he starts by laser-etching
a metallic surface with a
nanoscale pattern
inspired by the morpho wing.
He's hoping to create the same
water-repelling effect.
♪♪
When he drops water on the
surface he has created,
it is totally repelled.
The experiment is a success.
Water drops are not only
repelled,
they bounce back.
With this material,
Chunlei's team seems to have
created an unsinkable metal.
And what we did was, we actually
utilized in,
build a metallic assembly
with a super-hydrophobic
surface,
so that the hydrophobic surface,
they are facing each other.
And if you put this
metallic assembly inside water,
and because the inside of the
assembly is super-hydrophobic,
so that it will push the water
out and will prevent the water
squeezing into the
metallic assembly,
and the air trapped inside
will keep
the metallic assembly afloat.
Fabricating a ship's hull
using this design would have
an obvious benefit.
But Chunlei believes
it could also help us adapt
to climate change.
And as our ocean level
continue to
go up in the future,
a lot of city will have to be
built on top of the ocean.
And if we can deploy this
unsinkable metal
for construction of the floating
city, then the city
will never sink.
♪♪
Who could have imagined
that one day a ship...
Or even a whole city...
Might rest on
a butterfly's wing?
In California,
researchers work on combining
transparency
and the opposite of
hydrophobicity...
Extreme water absorption.
What's at stake is not
rising water, but glaucoma,
a group of eye conditions
that can cause blindness.
Radwanul Hasan Siddique
at Caltech is working to create
a tiny implant that would work
inside the eye to help detect
this devastating condition.
So, in our lab,
we make an optical implant
for continuously measure
the eye pressure
for glaucoma progression
measurement.
♪♪
Glaucoma is a condition
that damages the optic nerve,
most often caused by rising
internal pressure in the eye.
Today, an implant could provide
easy access
and constant monitoring
for a patient at risk.
But of course, anything inside
the eye needs to be transparent,
especially an
artificial implant.
Glass has around eight to ten
percent reflection.
And that reflection basically,
you can see a glare, right?
So if you see in the windows
or glass at some angle,
you can see glare because of
the reflection of the light.
But this glasswing butterfly,
although it's glass-like, but it
doesn't have any reflection,
or almost no reflection.
For Radwanul,
an implant in the eye
cannot be water-repellent
like the butterfly wing.
He needs to engineer something
different.
The implant is going to be
in the inside of your eye
in the aqueous humor,
which is a fluid.
So if it's, repels water,
then it's hard to implant,
and it won't survive there.
So in our case, we need
basically an opposite property,
which is super-hydrophilic.
♪♪
To make his implant,
Radwanul blends two chemical
compounds at very high speed.
Their combination creates
nanostructures like those of
the glasswing butterfly
out of a hydrophilic material
that patients' eyes
can tolerate.
These randomly distributed
dome-shaped nanostructures
conserve the transparent
properties of their model.
Because the gaps between them
are so narrow,
bacteria cannot get a grip
on the surface,
reducing the risk of infection.
Once we introduce
a nanostructure like the
glasswing-inspired
nanostructures on the implant,
it shows better performance,
has a better optical readout,
and also, it doesn't show
any anti-fouling,
any fouling properties, so...
Which means no tissue
are encapsulating,
no, no bacteria are sitting,
and we may take a measurement
over a year inside a rabbit eye
without seeing any kind of
fouling.
♪♪
Not all butterfly wings
are visually arresting.
The nanostructures in wings
are not only involved in color,
transparency,
or tricking predators.
Some of them serve to provide
direct metabolic benefits
for survival.
♪♪
Like all insects,
butterflies and moths
are cold-blooded.
No butterfly can take off
without a minimum of sunlight
to heat its body.
Dark-winged butterflies absorb
the heat of the sun
more readily and seem to have
an advantage over those
with lighter-colored wings.
♪♪
It might seem that
a white-winged butterfly,
like the cabbage white
butterfly,
would be operating
at a huge disadvantage.
And yet, in the early morning,
even on cloudy days,
it is one of the first arrivals
to gather nectar in
flower fields.
How does it manage it?
♪♪
At the Paris Institute
of Nanosciences,
Serge Berthier is interested in
this phenomenon.
So the white butterflies
cannot directly absorb light
through the wings
because they're white,
and reflect all the energy.
What they do when they need
to warm up is use their wings
as concentrators
before taking off.
They place themselves
facing the sun,
then open and close their wings
like this.
As it's very reflective,
it sends a lot of light,
and concentrates the light
on its back, the thorax,
where the wings'
abductor muscles are located.
So when the wings concentrate
the light,
the thorax will absorb
all this energy.
The reflective white coloration
acts as a mirror
to concentrate heat onto
the animal's body.
In the tiniest details,
Serge Berthier can verify the
way heat is sent to the thorax.
As with all scales, we see
a network of striations,
but what's particular to the
cabbage white butterfly
is that there is a network
of counter-striations,
in this direction.
And small compartments
are formed inside.
The cabbage white's scales
contain tightly packed
ovoid-shaped granules,
like eggs in a carton.
They reflect the sun's rays,
but not in all directions.
They focus the light and heat
like a magnifying glass.
The butterfly then angles
its wings in a way that sends
the heat down to its back.
This is how the butterfly
warms up.
The butterfly just has to
open and close its wings
to regulate its temperature.
In fact, it's the master
of its own temperature.
♪♪
Finding new ways to concentrate
sunlight is important
for humans, too, in the search
for cheap and efficient
replacements for fossil fuels.
In her lab at the
University of Exeter,
Katie Shanks is adapting
the cabbage white's
reflective nanostructures
to solar panels,
working to increase their output
while reducing their size.
So by looking at the wings
of the cabbage white butterfly,
we can actually
reduce the weight
a very significant amount.
So in initial studies,
we've been able to improve
the power-to-weight ratio
by 17 times,
which is, is a massive amount.
And what I'm specifically
looking at is using those
very lightweight nanostructured
wings to make our own
very compact advanced
solar panel
built into any materials.
♪♪
Today, by combining the
properties of the glasswing
and cabbage white wings,
researchers are hoping
to develop a new generation
of solar panels.
So the glasswing butterfly
would be for the surface,
the entrance aperture.
And the cabbage white butterfly
would be for the side walls,
just before the solar cells.
And overall, that means we get
this kind of
increased power output
from all the solar cells,
but not using as much
PV material.
And you can also make it
a lot smaller and lightweight,
as well.
I mean, all of the butterflies
and lots of other things
in nature have had to do this,
you know,
as, as they've developed,
they've evolved,
and they've tweaked themselves
to suit their surroundings.
And I think we're now realizing
we have to do the same
in terms of tweaking our,
you know, energy demands
and our uses and our materials
that we use to kind of make sure
we are also sustainable
and surviving,
just as the butterflies are.
♪♪
It's remarkable that butterfly
wings can offer protection
from predators and rain,
and also capture the sun's rays
to warm up.
But that's not the end
of their impressive biology.
Their delicate antennae serve
as highly sensitive
chemical-detecting noses.
They have those little pits
that are inside of,
are along the length
of the antennae.
And those sensory pits
are basically capable of,
of detecting kind of
chemical compounds,
and basically olfaction,
or, or smelling.
♪♪
The antennae of the male Bombyx
are loaded with a multitude
of microscopic sensing organs,
known as sensilla, that vibrate
at very high frequency.
They can home in on the one
kind of pheromone molecule
they are looking for,
among all the other ones
in suspension in the atmosphere.
In fact, some researchers
believe that the silk moths
have some of the most
highly developed senses of smell
in the living world.
Males are thus able to detect
a female
from over six miles away,
an extraordinary feat
which scientists working on
the detection of explosives
or toxic gases
would love to harness.
♪♪
Valérie Keller and her team
are part of a program
for protecting
civilian populations.
You can see on the antennas
that the sensilla's structure
is kind of like tiny sticks.
We drew inspiration from them.
In fact, we are trying to do
bio-inspiration by making
a synthesis in the lab
that enables us
to duplicate this architecture
you see in nature.
Mechanically duplicating
the anatomical genius of the
Bombyx is not an easy task.
Valérie Keller's team
is creating a forest of sensilla
via a chemical reaction
on a titanium base.
The result is a forest-like
arrangement
of titanium dioxide nanotubes.
If a chemical molecule
in the air
attaches to the nanotubes,
its weight changes the vibration
frequency of the forest,
slowing them down in a way
that can set off an alarm.
TNT, sarin gas,
and other toxic chemicals
all have their own weights.
Nanotubes are programmed
to react to those signals
to trigger alarms.
At the French-German Research
Institute of Saint-Louis,
Denis Spitzer foresees a
big future for these detectors.
We can come up with stationary
detectors, but then we can go on
basing them on the butterfly,
that is,
we can start to make
the detectors fly,
and the idea came to us
to implant these detectors
on drones, so that the military
or civil security people
can detect dangerous compounds.
It could be war toxins,
or sarin gas, or other extremely
dangerous compounds.
Because when the person feels
the first symptoms of gas like
that, it is already too late.
Drone surveillance
of large urban areas
could save major populations
from terrorist gas attacks.
♪♪
The amazing evolutionary tricks
of butterflies and moths
are not limited to their wings,
or their antennae.
Unlike many insects,
they don't have what might be
recognized as a mouth.
Most of the butterflies
and moths that we, we think of
have a sucking mouth part,
like a proboscis,
that is kind of coiled up,
that kind of is like a straw.
And it kind of extends outwards
with this cranial sucking pump,
and it sucks up
nectar from flowers.
♪♪
Many butterflies live
only for a few weeks.
But one, called Heliconius,
stands out,
with a lifespan closer to
six months.
♪♪
This relatively long-lived
butterfly fascinates
Adriana Briscoe
and Larry Gilbert.
One of the ways we think
they can live so long
is because they have changed
their diet.
They live a long time because
they have developed this ability
to harvest pollen.
♪♪
While most butterflies
feed mainly on nectar,
Heliconius adds pollen
to its diet.
The pollen sticks to the entire
length of its proboscis.
The pollen might keep
the butterfly healthy,
but Adriana has found
a possible medical application
derived from the way
Heliconius digests the nutrient.
She's collaborating with
chemist Rachel Martin.
This is the part of the
proboscis
where fluids can go in...
Mm-hmm.
And they can also go out.
I was really fascinated
to find out that
it acts like a sponge.
I was kind of always
picturing this being
like a giant drinking straw.
Oh, yeah, no.
You can see that there
are these ridges
shown in green,
and those are perfect grooves
for pollen to get stuck in.
When the butterflies
probe the flower,
and the pollen grains start to
get stuck in those grooves,
the butterflies then release
saliva from the tip
of their proboscis,
and that starts to glue things
together.
It makes sense that
the butterfly would have enzymes
that are really optimized
for getting into those little
nooks and crannies,
and digesting the protein,
because pollen is about
20% protein, so it's a...
That's a lot.
It is a lot.
The Heliconius's long life
might be explained in part
by this intake
of high-protein pollen,
which it actually digests
on the outside of its proboscis
thanks to a very particular
type of enzyme.
That enzyme is known
as cocoonase,
because it was originally
discovered in silk moths.
Silk moths have one version
of this enzyme which they use
to digest their silk cocoons
so they can escape.
If that enzyme
is not functioning,
they die in their cocoons.
By extracting this cocoonase
enzyme to reproduce
its dissolving properties
on a large scale,
Adriana hopes to alleviate
potentially serious medical
conditions like blood clots.
Blood clots are very common
in the United States.
It turns out you can take
cocoonase, and in a test tube,
you can mix it up
with a blood clot
and it'll break it down
into its component parts.
♪♪
Like the silk protein fibroin,
the cocoonase protein is also
compatible with human biology.
And the longevity Heliconius
may glean from pollen shows
how tightly the evolution
of butterflies depends on
the plants they feed on.
Plants and butterflies have
mutual evolution.
From egg to chrysalis,
many butterfly species are born,
grow up, and metamorphose
on individual plant species
with which they are associated.
You sometimes have a species
of butterfly or moth
that is the only thing
that can pollinate
a particular, a particular
species of, of flower.
And so, these really tight
interactions mean that
if we lose one of those members
of this partnership,
then you often end up losing
both species.
♪♪
The fates of butterflies
and plants are forever linked,
to such a degree that we cannot
hope to preserve
butterflies without preserving
their ecosystems.
Today's climate change may have
very unfortunate consequences.
♪♪
Spring has come to Mexico,
signaling to the monarchs
the time to return.
But these butterflies,
who migrated south in the fall,
now have to fly back north.
♪♪
How will they know which way
to fly?
Christine Merlin keeps a small
group of monarchs for study.
Just want a cooperative one.
You know, cooperate with me.
That one is actually in the
process of laying an egg.
She wants to explore and
understand which specific genes
trigger the migration
and guide them on their way.
This one just did.
Okay, this one is getting ready.
Christine believes that changes
in the environment
trigger a response
in the migratory genes
of the monarchs,
a process known as epigenetics.
I'm not as good as my student.
So with each butterfly's egg,
she analyzes a range of genes
to discover which are involved
with the timing
of the monarchs' navigation
and which
with the direction they follow.
One of the best example
of epigenetic changes
that occur in, in
monarch migration
is that of the recalibration
of their sun-compass orientation
from southward in the fall
to northwards in, in the spring.
And...
We do believe that
epigenetic changes
are responsible for this switch
in flight orientation.
Migrating monarchs also use
magnetic fields to guide
their flight orientation.
To find genes that allow
monarchs to sense
the magnetic field,
Christine uses a Faraday cage
that blocks the outside
electromagnetic influences.
There, she generates her own
magnetic field
to test the reaction
of the monarchs' behavior.
We use a magnetic coil
to test the response
of monarch butterfly
to the reversal
of the inclination.
And when butterfly sense
and respond to this reversal,
they start flapping their wings
really strongly,
they have an active flight.
And once we reverse the
magnetic field back to normal,
then the behavioral responses
extinguishes itself.
♪♪
The evidence is in: monarchs
are genetically programmed
to align with the magnetic
field, and we can see them
flap their wings
when they sense it.
When the seasons change,
causing a change of temperature,
a change of the angle
of the sun,
as well as a change
in the daily sunshine duration,
the butterflies' genes
trigger a signal to migrate.
♪♪
When in Canada and the U.S.,
the onset of fall signals
departure.
♪♪
"Colder... go south!"
When in Mexico,
spring tells them, "Go north!"
Given the extent that monarchs
depend on temperature,
it's not surprising that
climate change
worries researchers like
Delbert,
who monitors monarch populations
in part to understand the risks
we all face.
In that way,
by studying monarchs' biology
very closely,
it indirectly tells us
our own impacts on their
environment that they cover.
So we want to watch what's
happening to them,
watch how they're being
impacted, such that we know then
how other species may
potentially being impacted,
because they're being impacted
by those same climate change.
♪♪
Well, butterflies and moths
are really a big part
of the whole ecosystem.
So, if we were to lose
a certain species,
or groups of species, like
butterflies and moths,
we'd lose pollinators, for sure,
but we'd also lose
an important diet for birds.
We'd lose an important diet
for other insects, like
dragonflies.
We'd lose important diet items
even for people.
Because there are people that
like to eat these, these
as food items.
So, it's a kind of
a cascading effect.
It's not just that you would
lose this one insect.
You would actually lose many
members of the community
to which it belongs.
And that's, I think, the thing
that we're, we're working
against.
♪♪
Butterflies and moths
are inspiring scientists
and engineers
to create remarkable inventions.
From the nanoscopic structures
on their wings
that create color
and transparency
to their ability to repel water
and fight infection,
they offer lessons
about what's possible
at the very smallest scale.
But they also present us
with a warning
about what's at stake if we fail
as stewards of this endlessly
inventive natural environment.
♪♪