Nano materials and nanostructures
exist everywhere in our natural world.

Take a look at the wing of a dragonfly.

If we zoom in 100,000 times

and look at the transparent membrane,

we can see the nanostructures

which are invisible to the naked eye.

Graphene is transparent.

This is a molecular model of graphene.

To make it visible, it has been magnified

over 280 million times.

Graphene consists of 
only one single element:

carbon.

It's so simple.

However, graphene has 
lots of special properties.

It's the thinnest of all materials, 
only one atom thick.

It's the strongest material ever measured.

The in-plane carbon bond is stronger

than the tetrahedral carbon bond 
in a diamond.

At the same time, it is 
flexible and stretchable.

We can fully bend graphene 
and stretch it up to 20%.

It has the highest thermal conductivity 
of all materials, including copper.

It can withstand the highest 
current density at room temperature,

it has the highest intrinsic mobility,

which is 100 times more 
than that in silicon,

it is the most impermeable material,

even the smallest helium atoms 
cannot squeeze through.

Graphene will change the world.

There will be, for sure, a completely 
different intelligent society

in 10 to 20 years.

Let's spend some time 
thinking about the future.

Imagine if all the transparent 
glass windows

could constantly generate 
electricity under sunlight

and supply the energy 
for all the buildings.

Imagine if all the electrical vehicles 
and electronic devices

could be charged within 10 minutes 
and last for a few days.

Imagine if the sea water could be 
desalinated with a pocket device

so it turns into drinking 
water everywhere.

Imagine if smart electronic devices 
could be integrated into our clothes,

and some of them 
even implanted under our skins.

Imagine if light weight 
composite materials

could be stronger than ever

so it turns into 
the main structural material

for the body of ships, 
vehicles, and airplanes.

Imagine if electronic chips 
could do computations

a thousand time faster

with plasmons instead of electrons.

All these dreams will one day become real 
and revolutionize our society,

and I believe it will happen 
in our lifetime,

thanks to the exploration 
of this new nanomaterial.

But how to produce graphene 
is a serious problem.

Although graphene was known 
to exist in graphite,

most scientists believed 
that it would be impossible

to isolate a stable graphene.

In the 1930s, Landau and Peierls predicted

that 2D crystals would be 
thermodynamically unstable

and thus could not exist.

30 years later, Mermin further 
presented the analytical results

to fuller validate this hypothesis.

Until 2004, when two scientists,

Andre Geim and Kostya Novoselov,

used scotch tape to produce graphene.

By putting tape on graphite flakes 
multiple times,

each time peeling off a layer,

the graphite will become 
thinner and thinner.

Although most of the area consists 
of thin graphite flakes,

a few small pieces 
of a single layer graphene

were finally isolated.

Since then, thousands of scientists 
started to do research

based on this tiny piece 
of single layer graphene

using the scotch tape method.

Can you believe that 
the Nobel Physics Prize in 2010

was awarded to these two scientists

based on their groundbreaking 
scotch tape experiment? (Laughter)

Obviously, it is not a practical way

to mass produce graphene
and make useful products.

Nowadays, tons of small flakes 
of multilayer graphene,

strictly speaking, thin graphite flakes,

can be produced using 
the chemical exfoliation method.

It can be mixed into tennis
racquets or bicycle tires

to enhance the strength 
and lower the composite weight.

However, the material produced is black,

which is inconsistent 
with the transparent property of graphene.

If the color is black, it means 
the flakes are too thick.

At the same time, the flakes are too small

to do the cool things
with that I was talking about.

As an experimental researcher 
working on graphene,

I need lots of large area 
single layer graphene

for my experiments.

However, I couldn't find 
any research group

which could supply me 
with high quality graphene

in the Netherlands at that moment.

I traveled between Leiden University 
and Delft University every day,

and tried to figure out how I could 
grow large size graphene samples.

With the existing facilities available,

I couldn't isolate high quality graphene,

either because the equipment had 
very rough control of the gas flow,

or because the heating area was too small

to grow larger size samples of graphene.

Even the power of the heater 
was not sufficient

to reach 1,000 degree Celsius.

Day after day, I woke up at 6 am,

and returned home at midnight.

I tried all the possibilities 
that I could think of.

However, what I got, was only frustration 
and reiteration of the problems.

I thought: "If I continue in this way,

I will never finish my PhD research."

Four months later, I decided 
to stop wasting time

and make a furnace myself.

Thanks to my supervisor, and the faculty,

I received extra budget 
for the equipment.

At the same time, I also won 
the Young Wild Idea Prize,

worth 10,000 EUR,

which allowed me to spend the money 
freely on the material.

I still remember that moment
on Tuesday, April 17, 2012.

After a whole year of working long days,

I started the first testing 
of my own setup.

The vacuum pump I grabbed 
from somewhere in the lab

was over eight years old and had run 
for over 29,000 hours.

Not only that, but the pump 
will stop running

once the temperature 
reached over 40 degree Celsius.

So I bought a small fan costing 30 EUR,

which did a perfectly good job 
of cooling the pump.

This is the furnace I have built.

I will explain the advantages 
of this homemade setup.

The furnace can heat up 
the 1 inch quartz tube

to over 1,000 degree Celsius

with a temperature fluctuation 
of less than one degree Celsius.

There is a transparent 
bullet proof Lexan cover,

which can protect against 
any possible gas explosion

and secure the safety of the researcher.

There is a small hand wheel which can 
remotely control the moving of the furnace

to the left

and to the right,

with a gear and a chain,

similar to chain gears on a bicycle.

With this design, I was able to heat 
the sample and cool the sample

10 times faster
than any commercial equipment.

The cost of this setup 
is less than 20,000 EUR,

which is over seven times cheaper 
than any commercially available equipment.

All the components can be optimized 
and well controlled.

It delivers a much better performance.

I enjoyed conducting
the experiment with my own setup.

This is the graphene I have grown.

The graphene crystals 
grow like snow crystals.

Methane gas,

which accounts for about 80% 
of natural gas used for cooking,

can decompose to carbon atoms

on copper substrate

at one 1,000 degrees Celsius 
in an inert gas environment.

The carbon atoms will attach to each other

and form carbon rings 
with honeycomb structures,

such as in graphite.

I can use the carbon isotope 
to mark the growth procedure.

Can you imagine, the size
of an individual graphene crystal

reached over a few millimeter,

which is over one million times larger 
than the size of the carbon atom?

Can you believe that this sample 
was made six months ago,

and the single layer graphene can still 
protect the copper against any oxidation?

The graphene crystals 
will grow larger and larger,

and connect with neighboring 
graphene crystals,

to finally form a continuous film.

Once there is no bare copper,

the graphene growth will stop.

So in the end, we will have a single layer
high quality graphene film.

My colleague and I proved 
for the first time

that the quality 
of this synthetic graphene

is as good as the one 
with the scotch tape method,

however, the size is considerably larger.

To mass produce graphene, 
and reduce the cost dramatically,

a bigger and better furnace 
was designed and built.

The furnace has a larger quartz tube,

and the furnace will always 
maintain a constant temperature.

Once the graphene growth has finished,

the only thing I need to do is to move 
the furnace completely away from the tube

and take out the graphene sample.

Immediately, I can start 
the second graphene growth cycle.

The efficiency of high quality 
graphene growth

can be improved ten to twentyfold

and the energy consumption 
will become much lower.

If we build hundreds of bigger furnaces,

the mass production of graphene 
will become possible soon.

There is a layer of graphene
on a transparent substrate.

I can see you all through it.

But there is something special.

It is conductive

and flexible.

(Applause)

Now you can imagine all kinds
of future applications with this graphene.

Currently, the price
of this small piece of graphene

will be around 1,000 EUR.

I believe the price of this graphene 
will go down to less than 1 EUR

within a few years,

because the material we use 
to produce graphene,

such as

natural gas and copper foil,

are widely accessible.

All of us will have access to graphene 
in the near future,

and realize this dream.

Remember that I told you
we are going to have better world.

Now, I cannot show you 
the transparent glass windows

which could generate electricity,

and I cannot show you 
the electronics in my clothes.

But I can show you something 
you have never seen before.

There is a transparent graphene 
patterned into wired structures

on this transparent polymer wing.

The graphene is so special

that once we put a tiny amount 
of energy, it will shrink.

And graphene is so strong 
that it can lift up

this polymer wing, which is 
a thousand times heavier,

and mimic the flapping
function of a bio robot.

Look at what I have done 
and achieved in these few years.

With all of you involved in my endeavor

to mass produce high quality 
large scale graphene,

I believe we can make our dream 
come true together.

Thank you.

(Applause)