Amaia Zurutuza Elorza Grapheneako zuzendari zientifikoa

“I hope that the applications of graphene are on the market before society loses interest”

2018/11/30 Agirre Ruiz de Arkaute, Aitziber - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

Comes the era of two-dimensional materials in technology. The graphene was the first to discover it, but that only opened the doors to a new world. How many amazing applications would scientists and engineers have imagined since! Graphenea is the support of all these dreams in Donostia and we have met with its scientific director, Amaia Zurutuza. It has been explained that it has devices in the hands made with graphene.
Ed. Jon Urbe/©Argazki press
A few years ago a great hope arose around graphene. You yourself abandoned your field of research and jumped to graphene full to the fashion material. How was it?

I was then investigating pharmaceutical abroad. He was investigating polymers to control doses of drugs. I tried to return to the Basque Country and saw an advertisement of nanoGUNE that offered work in a new company in the graffiti sector. I didn't know what graphene was, but from the point of view of the application you could do everything with it, and that attracted me. Very soon after I started working, the Nobel Prize was awarded to those who discovered graphene, and from then on the interest in graphene grew exponentially, even in society.

Live, right?

Yes, the market is very small. For the moment it is only used in research, they cannot be many producers. Last year it contributed 16 million euros worldwide. As a matter of fact, Samsung is not included in a new market if its size is not, at least, a billion dollars. 16 million euros are only soda for them.

There is great hope in graphene, but it is really a very simple material: fine carbon sheets. What makes it so special?
Ed. Jon Urbe/©Argazki press

It is simple, yes. It was discovered that the graphite, the main component of the pencil, was being cleaned. It is an individual layer of graphite. The carbons acquire a hexagonal structure, as a beehive, but forming a sheet of a single atom of thickness. Two-dimensional. The special feature of graphene is that electrons move quickly on these monoatomic plates as if they had no mass. Due to their large number of rings, electrons are dislocated in all the material. They have no obstacles to move. Thus, if in graphite electrons move quickly, in graphene it is much faster. For example, silicon moves at a maximum speed of 1,000 cm2/(V·s) and graphene can reach 200,000 cm2/(V·s).

The so fast movement of electrons will give you great utility in electronics. Proof of this speed is the recent 5G telecommunications application that allows to download 25 films in just a second.

At the moment no application has arrived on the market, but what do the latest prototypes of graphene consist of?

There are many good prototypes. For example, in optoelectronics, the application of photodetectors is interesting: night vision cameras are being developed for cars. Applications in telecommunications, combined with silicon in optical fibers, are also being developed. I see them especially the greatest future. Two or three years ago we also spoke of making flexible mobile screens. What happens is that the full mobile should be flexible, otherwise it doesn't make sense. And for now it is not possible.

In the field of medicine, for example, biosensors are being developed. Biomolecules have very good interaction with the aromatic rings of graphene. And since graphene has a proportionally large surface, it quickly detects any change in biomolecules, all interaction. For example, it would serve to find biomarkers in blood.

Electrodes are also being developed to stimulate the brain. The electrodes currently used are platinum, very rigid and thick, and graphene is monolayer, which allows for better brain stimulation. Tests have already been done on animals. From here many applications could be derived to stimulate the brain and cure many diseases.

Since you jumped into graphene, what discovery of graphene has been the one that has created the most emotion in you?

It is a material that still has many surprises. All are interesting, but this year the superconductivity has been the hot topic. If you overlay two layers of graphene at a given angle, graphene presents superconductivity. We didn't even imagine that I was one or two years old. What will you do!

Ed. Jon Urbe/Photographic Press
Graphene is the first two-dimensional material found, but opens up the possibility of obtaining many others. What special feature has to be two-dimensional compared to conventional three-dimensional materials?

The different behavior of electrons brings new capacities. In graphene, for example, electrons move faster, while in simple layers made of molybdenum disulfide, light is absorbed differently: it emits much more light when there is a single layer than the three layers. In the end we know the three-dimensional materials, but when we refine and obtain a two-dimensional, other characteristics appear. And you say: “Uau! News How it emits so much light if there is almost no material!”

Could we get a two-dimensional of any three-dimensional material?

More or less. With many yes, with all no. At the moment, scientists are making great efforts to create two-dimensional materials and look for new features. And with many materials. What happens is that then not all two-dimensional materials are useful.

It has been treated, for example, to create two-dimensional silicon: silonym, which would be equivalent to graphene. But it is not stable. If it were stable, it could have interesting features, but it is not stable. It has also been treated with germanium, which is not stable either. It cannot be produced. There is another black phosphorus in which electrons move very quickly. Pending to see.

So, in reality, not all atoms serve to create such structures?

Well, the question is difficult. For example, hexagonal structures are the most thermodynamically stable, which conditions a lot. Carbon is a very special atom, since it allows to create many spatial structures, and almost all stable. The diamond itself is stable, although it requires very demanding generation conditions. It is the particularity of the carbon.

For the moment, what stable two-dimensional materials have been achieved?

For example, there is one very similar to graphene, the hexagonal boron nitride. Instead of carbon, this hexagonal structure is formed by boron and nitrogen. In this case, electrons do not move quickly, but it is a very good insulating material. Therefore, it has an interesting property: it can be used as a substrate for graphene. In fact, as we usually place graphene on a substrate for any application, it has an impact on the electrons of graphene, which no longer move so fast. But if we put this insulating material between substrate and graphene, these electrons still move faster. That's what we're doing right now.

And there are more two-dimensional materials: molybdenum disulfide (MoS 2), wolfram disulfide (WS 2), wolfram dyelenide (WS e 2), etc. All of them are semiconductors, similar to silicon. They have no hexagonal structure and are not monoatomic structures, but layers of three atoms. They are increasingly creative.

Ed. Jon Urbe/©Argazki press
There is great hope in two-dimensional materials and investment is similar, right?

Europe decided strategically to invest the money in graphene. Graphene Flagship is a project that has given it a lot of strength. In ten years he will invest a billion euros. It is not the only bet of Europe, of course. He financed another major ten year project: Human Brain Project, for the creation of a supercomputer.

After so many works, what applications actually converted through graphene would fulfill more?

For me, seeing the graphene in the products would be terrible, because we have been investigating for 8 years. But we know we need patience because every new material needs many years to market it. In the case of silicon, they spent more than 20 years until their use in transistors for computers. And now its impact on the market is huge.

But if you had to choose an application… Well, using it in photonics or electronics would be very good, but if you had to choose one, perhaps, in biomedicine. I would like to have a good biosensor at home, to know at one time, for example, if you have cancer or not.

So much hope in graphene can generate strong social and media pressure in researchers. You how you live it: Do you have a load or motivate you to work?

Sometimes it is not easy to manage these media requests. But I think that for the moment the interest is positive. It is important that society is interested in graphene, since it is what allows to obtain money for investment. Yes, I hope the apps are on the market before losing that interest.

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