Published: 10.01.2022
Professor Tomáš Wágner has been involved in material research all his life and is expert on the elements of the chalcogen group. He is a chemist but his research is also into electrical engineering and optics with a possible overlap in medicine, environmental protection and safety. “Each element has a specific constitution and electron structure. Translated to human life, each element is a separate being. It has important properties that can be combined,” says the excellent scientist Professor Tomáš Wágner from the Faculty of Chemical Technology who has obtained a unique and prestigious U.S. patent for memory information recording.
Have you achieved your goal?
I wasn’t really chasing for a U.S. patent but the circumstances played into my hands. I had an exceptional opportunity and I grabbed it.
What opportunity?
I’ll start with a story. At an international conference on chalcogenides in 2010 I met Professor Ovshinsky, an 88-year-old American inventor and scientist, a visionary and a very rare person. He himself founded several companies. He explained his scientific credo to me on a single coin. One side of the coin showed the word “Information” and a human head with the brain highlighted. The other side of the coin showed a symbol of the sun and read “Energy”. And this is exactly the driving force of material research. This is where we belong with our smart materials.
Energy stores information?
Thanks to their properties, chalcogenide materials can be used wherever data and information need to be stored. These properties push the human population forward. The area of material research is constantly evolving because every year our population generates hundreds of exabytes (exabyte is a unit expressing the amount of digital data – editor’s note). And this information and data, whether it’s photos or documents, must be stored and processed in the virtual world.
And your patent is related to data storage?
Our research focuses on thin chalcogenide layers containing not only selenium but also other elements such as silver, germanium or antimony. We make amorphous alloys and use these alloys to apply thin nanometre-scale layers.
Do your materials ensure better information storage in the virtual world?
Yes, you can put it like that. But it is a very lively area involving a number of research groups. We used our opportunity to get closer to the application sphere. We study thin layers and individual memory cells where we can test binary encoding. It turns out that with these materials we can use DC voltage to establish a conductive connection or generally change the electrical resistance of the material. The conductive phase is provided by introducing voltage and creating a conductive contact in the material; simply a nanowire which connects two electrodes. When the voltage polarity is reversed, the wire disconnects and the material is no longer conductive. But we can even get much further and achieve multi-level encoding and smaller dimensions. We tested micrometre-scale memory cells. And that is the core of the invention. We are talking about a thousandth of a millimetre. The production level at which the research aims is even three orders lower. However, this is no longer possible to examine in our conditions because it requires very clean spaces and special laboratories without dust particles. Even chemists themselves are polluting elements in clean semiconductor processing plants. For example, they need a special dust-free suit.
To put it simply. The information generated by our company needs to fit in the smallest area possible. And there it should be processed effectively.
Yes. Our task was to demonstrate that our material works reliably. This is a different way of storing data than is currently used in memory media. This technology promises up to a thousand times faster operation, up to a thousand times longer life and up to ten times higher data recording density. It was necessary to demonstrate that this material has proven properties and that both the bulk glass and the thin layer work as they should. In the methodology we provided evidence that the memory cell established a connection and that data storage was stable. For everything to work we had to create our own software. We were sure and aware of the fact that we were working on something new and unique. That’s why we began to believe that our research could lead to a patent.
At the moment you have the invention patented.
The U.S. Patent Office accepted it last year on 29th December. U.S. patent is a very complex procedure, we fought for it for three years. The Centre for Technology and Knowledge Transfer of the University of Pardubice provided us with a complete service in the patent procedure because it takes a lot of administration.
But it was worth it.
These patents don’t just fall into your lap. It is my only U.S. patent and I consider it a very pleasant reward on my scientific journey.
What is the procedure of applying for a patent?
The patent procedure consists of several stages. First you prepare a Czech patent and submit it to the Patent Office. They examine what you want to patent, look at the literature and check that your research has previously not been published in other patents. If you pass, you say to yourself that you could apply for a higher-level patent, which is the European patent or the U.S. patent. They ask you various questions that you need to explain. It is actually a verification of the discovery. And if your discovery is successful, you have to apply for validation in the country. In the process of validation, the research is again broken down into pieces and examined. If everything is fine, the Patent Office recognizes that the matter is suitable for patenting.
And what is going to happen next?
The patent is now freely accessible. We hope that someone will notice it and use it in further applications. In this respect, it is good to know that every top company has its own research department. This idea can catch attention of one of the technologists who can then use our knowledge. We have already asked a multinational company which produces monocrystalline silicon, silicon plates and integrated circuits. They could be interested in our technology. They have branches all over the world, even in America.
How does your research translate to everyday life?
An increased amount of data that for example a computer can process, store and learn from. Everybody uses a mobile phone or a computer. Today, even a vacuum cleaner is smart. Thanks to chips and electronic components, smart devices have a built-in memory which helps control logical operations. As far as our memory storage is concerned, it is important to know that this is non-volatile memory.
What does this mean?
We store a piece of information. When external voltage is disconnected, the information remains stored. This is another added value of our memory materials. Conventional memory types work on the principle of transistor and CMOS (Complementary Metal Oxide Semiconductor) technology and require voltage to retain the information stored.
In addition to electronics, where else can your materials work?
Memory cells can be used in memory neural networks and facilitate imitation of the functions of the human brain. The brain creates neurones and synapses (conductive connections). Memory cells have plasticity and they can be charged to various voltage levels. The passing signal is processed in a certain way. One day, artificial neural networks could replace the activity of the human brain or parts of the nervous system. You see, once I wanted to study medicine and now it is returning to my research.
How would the networks replace the brain?
For example, after injury, parts of the missing nervous system in the human body could be replaced. And the body could continue to work. Or people could start to walk or see again.
That is a great challenge…
I’m very excited about it. But it is more a challenge for my successors.
Speaking about your research, what chemical elements can be found in your materials?
We primarily focus on semiconductor materials including a number of alloys and chalcogenide compounds. These are alloys or compounds with a number of elements but they always include oxygen, sulphur, selenium or tellurium plus some other elements. These materials can be prepared in different forms. These forms include bulk material, fibres, pills or thin layers. Our research primarily focuses on chalcogenides of sulphur, selenium and tellurium. Currently, our research also includes oxygen compounds. They can be prepared as amorphous or crystalline. We are interested in the amorphous (the structure of materials is not firmly arranged – editor’s note) and nanocrystalline structure.
Why this specific structure?
Amorphous material can be used to create any shape in the form of a lens or fibre that conducts a light beam. Alternatively, pills (tablets) that can be pressed together. The interesting thing about thin layers is that they are of a nano size, thereby providing a potential in nanotechnologies. We are interested in their structure and photonic properties. Photonic materials are suitable for conducting and processing of optical signals or for generating signals including lasers or amplifiers. Electrical properties are related to materials that can be used for memory storage.
How would you explain to the general public what material research is?
This type of research focuses on glass, semiconductors or ion conductors where the dopants can be transient metals or rare earth elements. Nowadays, a lot of communication is conducted through optical waveguides and optical fibres, which speeds up communication. This is where the other side of Professor Ovshinsky’s coin comes into play: “Energy”, its generation, transport and storage. During the covid pandemic, human temperature was taken by contactless methods. These devices also include chalcogenide glasses. But these materials can also be used in the area of security as they are capable of face recognition, for example faces of terrorists. Infrared optics made it possible to use laser knives in medicine. They cut your tissue but it doesn’t bleed because the wavelength coagulates the tissue and prevents bleeding.
Why did you choose chemistry as your specialization?
My father used to be a general practitioner and I wanted to continue in his footsteps. Although the idyllic idea of a village doctor who is in his office in the morning and visits his patients in the afternoon no longer exists. I wasn’t accepted for medicine and life sent me to chemistry. I do not regret it at all. In the autumn of 1977, I enrolled in the University of Chemistry and Technology in Pardubice. It was a huge information shock for me because our grammar school had focused on humanities with an emphasis on biology. Despite the fact that I had graduated from chemistry as well. At university I met Professor Frumar. In his passion for science and material research he became my lifelong model and guru. Later, we became inseparable colleagues and friends. He was an enthusiastic scientist who was able to excite people and focused on things that really attracted me. Semiconductors! I returned to my child enthusiasm for electrical engineering, radios and tape recorders. I had always wondered how all these instruments work. And here with Professor Frumar I revealed their essence. I continued in his group and in the fifth year I wrote a diploma thesis on chalcogenides. And I have been attached to them ever since as you can see.
Why are you so fascinated by inorganic chemistry?
Each element has a constitution, an electron structure. Translated to human life, each element is a separate being. It has important properties that can be combined.
Can you imagine doing something else in your life?
I have always been interested in the nature of things and their functioning. But yes, I think I would enjoy medicine and biology where I could try to understand why mechanisms work as they do. I am fascinated by nature, where everything is perfectly organized and we are trying hard to get at least close. Also for this reason, my big hobby is beekeeping.
Is there anything you failed to achieve in your life?
For example I failed to push through the construction of a large centre for material research in Pardubice, which should have been located in the campus on the grass field behind the Faculty of Chemical Technology. Five years of work, preparation of a scientific and construction design, creation of a scientific team, work with designers and architects, all of this came to nothing. A great life experience!
We started our interview with a coin and we will finish it with a coin. What do you have in common with the book “Denier hoard dating back to the end of the 10th century and found in Chýšť”?
I performed an element analysis of those deniers. When archaeologists found deniers near Chýšť in the Pardubice Region, they were donated to the Museum in Pardubice. The historian Ladislav Nekvapil asked me whether I could find out what material the coins were made of. I confirmed that they were made of an alloy of gold, silver and copper. These coins are 11 centuries older than the coin of Professor Ovshinsky. Even after so many centuries, they emit huge energy and contain a lot of historical information.
Are you interested in history?
I have been interested in history since grammar school. Czech history and the history of the Pardubice Region. The work on the deniers was a deviation from my main specialization but I enjoyed it a lot. I don’t have plans for twenty years to come, but I try to use every moment that makes sense. And this one I used.
Prof. Ing. Tomáš Wágner, DrSc.
(1958)Graduated from the University of Chemistry and Technology in Pardubice. Works at the Department of General and Inorganic Chemistry of the Faculty of Chemical Technology. In 1990 was awarded the candidate of sciences (CSc.) degree and in 2005 became professor of inorganic chemistry. In 2016 was awarded doctor of science (DrSc.) in chemistry. After the revolution completed a two-year foreign fellowship in Edinburgh, Scotland and spent two and a half years as a researcher in Canada. Gave lectures at scientific conferences and universities in Japan, China, South Korea, America, Russia, Great Britain, France, Greece or Italy. Held a number of international scientific events in Pardubice. In 2014 created a research team focusing on advanced non-crystalline materials. Trained a number of successful students who continue the research and are recognized in the Czech Republic as well as abroad. Currently works as a researcher at the Center of Materials and Nanotechnologies (CEMNAT). So far has published more than 230 scientific papers; h-index 31. At the end of last year obtained a U.S. patent entitled “Method of forming a metallic conductive filament and random access memory device for carrying out the method”.
TEXT by Věra Přibylová/PHOTO by Adrián Zeiner
