25 Interviews for the FNP’s 25th Anniversary: Zbigniew Rozynek, PhD, and Filip Granek, PhD Eng., the authors of a technology for making new-generation transparent conductive film, talk to Aleksandra Stanisławska

The Foundation for Polish Science (FNP) celebrates its 25th anniversary this year. To mark the occasion, we have invited 25 beneficiaries of our programmes to tell us about how they “practise” science. What fascinates them? What is so exciting, compelling and important in their particular field that they have decided to devote a major part of their lives to it? How does one achieve success?

The interviewees are researchers representing many very different fields, at different stages of their scientific careers, with diverse experience. But they have one thing in common: they practise science of the highest world standard, they have impressive achievements to their credit and different kinds of FNP support in their extensive CVs. We are launching the publication of our cycle; successive interviews will appear regularly on the FNP website.

Pleasant reading!

Printing Nano-scale Electrodes

Zbigniew Rozynek, PhD, and Filip Granek, PhD Eng., the authors of a technology for making new-generation transparent conductive film, talk to Aleksandra Stanisławska.


Pictured: dr Filip Granek and dr eng. Zbigniew Rozynek / Press materials XTPL

ALEKSANDRA STANISŁAWSKA: A physicist meets an engineer… how exactly did your collaboration happen?

FILIP GRANEK: We wouldn’t be here if it weren’t for a series of lucky coincidences that originated, interestingly enough, from the Foundation for Polish Science. Zbyszek and I are beneficiaries of the FNP’s Homing Plus programme that encouraged young Polish scientists who had gone abroad to come back to Poland and conduct their research here. Thanks to the programme, I was able to complete my own project to search for methods of making flexible solar cells. I worked on it at the EIT+ Wrocław Research Centre after returning from the Fraunhofer-Institut für Solare Energiesysteme ISE in Germany, where I spent a few years. The concepts developed within this project triggered a specific kind of bold thinking in me thanks to which I am doing what I do today.

ZBIGNIEW ROZYNEK: Thanks to funding from the Homing Plus programme, I also came to Poland after ten years abroad, including six in Norway working on my PhD and a postdoctoral fellowship at the Norwegian University of Science and Technology. A lot changed in Poland while I was away. First of all, the research infrastructure improved, finally reaching a world standard. In addition, financial support was made available to scientists with significant achievements. Thanks to funds from the FNP, I could work on my own research at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw. The project involved developing new methods for making colloidal microcapsules, which can be used in the pharmaceutical, food or paint industries, among others, for example, for slow release of active substances. I used different physical phenomena to produce and study the properties of these microcapsules. We take advantage of some of those phenomena, related to self-ordering of micro- and nanoparticles, today at XTPL. Thus, a project completed thanks to the FNP and earlier projects I worked on in Norway contributed indirectly to the technology currently being developed at XTPL. An in-depth understanding of physical phenomena was possible thanks to fundamental research conducted at the company, on which our current technology is based.

And how did you two happen to meet?

FG: I met Zbyszek at a training course organised by the FNP. It was the Fast Track course in the SKILLS programme for scientists who have the beginnings of a new technology and are thinking about commercialising their research results. Just a few years ago, there was no obvious path in Poland for people who, besides working for academic degrees and preparing publications, wanted to work on commercialising their technologies. Fast Track was an extremely inspiring meeting, offering open-mindedness, sharing of ideas and no hint of rivalry. We both went there with ideas – each with his own – that we thought stood a chance of becoming a market success. But when we started going into the matter in greater depth, something completely new emerged at the point where our competences met: the idea to pursue a joint project, different from the two we had originally planned.

ZR: We had no idea that the fields we’d been involved in separately until then, could work together. The atmosphere of the course was such, however, that we felt we really wanted to do something, to change things. We did some brainstorming over an evening beer and outlined a very preliminary idea on a piece of paper, to make ultra-thin electrodes using a new method combining knowledge from different areas of science.

Which particular competences yielded this joint project?

FG: We complement each other perfectly. Zbyszek is a physicist who has been involved in fundamental research in soft matter physics for many years. My field is electronics and materials engineering, I also have experience in implementing and patenting inventions (with about 30 patents and patent applications to my credit). So, in this duo we have fundamental research that shifts the boundaries of knowledge about the world, and on the other hand – applied research that seeks applications for fundamental research. This has resulted in a synergy that surprised us both.

ZR: I specialise in the physics of fluids, emulsions and using external electric and magnetic fields to arrange molecules in those fluids. In other words, I use different methods to get molecules in a colloidal suspension to assemble themselves in specific structures. I arrange small molecules in this way to adjust them to my needs.

FG: I am a supporter of using solar energy on Earth. My research focuses on how to use simple, cheap and readily available materials to build effective solar cells. Such effective methods include methods for printing advanced electronics. And ultra-precision printing of the kind we are developing at XTPL fits in perfectly with my existing scientific interests.

How can these two fields be used to produce transparent electrodes?

ZR: I can use the ability to arrange molecules in a fluid to assemble them into very thin conductive lines. Such conductive lines can be used in solar cells, for example, or anywhere in electronics where ultra-thin electrodes invisible to the eye are required, such as displays or touch screens.

FG: We decided to transpose all that Zbyszek had done in the macro scale to the nano scale, and place the structures he arranged so precisely on a solar cell. I thought this could yield a new method of printing nanomaterials offering a still unheard-of level of precision. And this observation was a starting point on XTPL’s road. The smaller the electrodes carrying the electricity generated by a cell, the more efficient the whole thing. And we can make an exceptionally small and dense mesh of these conductive wires. A similar mechanism is involved in displays: electricity is brought to them through electrodes that shouldn’t shade the image so that it can reach our eyes without interference. We make electrodes so thin that they are extremely transparent for visible light. Moreover, we can do it using a potentially cheap, repeatable method.

But there are already materials from which transparent electrodes for displays and solar cells are made. What makes the method you designed better?

FG: The materials used for this today have serious limitations, while our method can eliminate them. Indium tin oxide, widely used today, has a crystalline structure that makes it lose its properties during bending. This means it cannot be used in flexible displays, for example. In addition, the price for indium is high and the global resources of this material are largely controlled by one country: China. That’s why many research centres around the world are trying to develop a method to replace indium with more easily available materials. We are currently experimenting with silver, an excellent conductor that we have arranged into a mesh invisible to the human eye. We are also looking for alternative, cheaper materials.

ZR: Indium and tin electrodes form an unbroken layer covering a solar cell with a “carpet”. We produce a mesh of single silver lines that ensure electrical conductivity and transparency appropriate for many applications.

How thin are the electrodes you produce?

ZR: We’ve managed to produce wires that are up to 400 nanometres (nm) across. Many applications don’t require this degree of miniaturisation, and I think slightly wider electrodes, i.e. about 1 micrometre (µm) [1 µm = 1000 nm], will do just as well. Overcoming the 1 µm barrier was a big success for us and one of our milestones.

FG: This is a quantum leap in relation to methods used today, like digital printing, screen printing or inkjet printing. With these methods, it’s very hard to go below a resolution of 20–50 µm.

Does this mean you have a machine for printing nano-scale electrodes?

FG: We don’t want to say too much about the technical details, because that’s the essence of our invention. Of course our printing process looks different than ordinary printing. All I can say is that it doesn’t require any extraordinary conditions or outlays such as a special clean room. We are able to achieve nano-scale precision without “space” aprons or dust free gloves. We made our first prints of satisfactory quality in a garage on the outskirts of Wrocław with a cat walking under the desk. And that’s the beauty of our method: we are getting excellent results at low cost. What’s behind it is simply a great idea.

Do you still work at a garage near Wrocław?

FG: Not any more, but it was the centre of our universe until recently. We rented a terraced house with a garage that served as our office, laboratory and hotel. Zbyszek lived in Warsaw and Sebastian Młodziński, the third founder of our company XTPL and its CEO, lived in Kraków.

ZR: It was in true start-up style, really American. Life revolved around a garage where things sometimes explode and sometimes stink. On the first floor we had a “conference room” and a bedroom next to it. The latter was essential because we met up for a few weeks at a time and worked in continuous stretches, including weekends, 16 hours a day.

FG: As of this September, we are headquartered at the EIT+ Wrocław Research Centre, an excellently equipped high-tech campus. We have access to advanced equipment that a small business like ours could never afford on its own. We also have access to experts from other fields there. We’ve built a team of 15 people who work at our new laboratory. Six of them have PhDs and have worked abroad but chose XTPL as the place where they can develop freely.

How did you manage to find the funding to develop your own business?

FG: Looking for our first investor with nothing more than a piece of paper on which our idea was outlined wasn’t easy. We were lucky to meet an investor, Konrad Pankiewicz, who believed in us and put up the money to set up a laboratory in the garage and build an experimental system confirming that such precision printing would be possible. Today Konrad is member of our team, head of the supervisory board and our business advisor. After that we were able to obtain funding from an investment fund for start-ups operating in the high-tech sector. That money was enough for a good six months of research and a patent application, and then once we had achieved the results we’d planned, we applied for much bigger funding to develop the project. We wanted to find Polish capital, and we did. We obtained almost 4 million zlotys from our investors, we have a subsidy for research and development from the National Centre for Research and Development to the tune of 10 million zlotys. This budget allows us to spread our wings and move forward really ambitiously with what we’re doing.

How close are you to the implementation of your solution?

FG: We are considering the first experimental implementation of our technology on the Polish market, which would be good both in terms of logistics and in terms of accepting a level of risk. We certainly have a serious advantage over the competition because our printing technology is cheap, fast, repeatable, ultra-precise and can be applied on a wide scale. Interest is already being shown by manufacturers of solar cells, displays and printing machines. Among others, we are holding talks with the Chinese company Trina Solar, the world’s biggest manufacturer of solar cells, and with DuPont of the United States, which supplies materials for solar cell production. Printing structures under 1 µm in diameter opens many other doors as well – we are getting queries related to military applications and unique security features for banknotes or securities.

What about your scientific work? Did it have to give way to the company?

ZR: I still have one foot in the academic network, where I develop the physics of microcapsules. I have significant achievements in this field: a dozen or so scientific papers, including two publications in journals from the Nature group, thanks to which I opened up new areas in this field of science, and I think they are worth exploring. I intend to work in science and business simultaneously for as long as I feel that I can handle it without any detriment to either segment.

FG: As the leader and biggest shareholder of the project I knew from the beginning that our undertaking would succeed only if I put my whole heart into it, without getting side-tracked into anything else. I abandoned an academic career rather quickly, though it was painful. Perhaps the moment will come when I return to research. Who knows?

How do you imagine the future of your business?

FG: As a company we want to become a supplier of equipment for precision printing of nanomaterials for the solar cell and display unit industries, among others. We are also investigating new materials that can be printed using our method. We’re exploring new sectors in which our solutions could be useful. We want not only to supply tools for nanostructure printing – printers and unique ink – but also to launch our own production of components that we can make based on our technology. I’d like XTPL to avoid the fate of a small business operating locally, and in the longer term to become a company employing several dozen leading scientists and engineers and find its place on the global high-tech scene. I deeply believe that such activity is possible in Poland. And I’m very grateful to the FNP for enabling us to pursue it by giving us business knowledge we needed to launch the project and letting us know when we were working abroad that we were welcome in this country and could find a place for ourselves here. That is precisely what we have succeeded in doing.

FILIP GRANEK, PhD ENG., co-founder and science and technology director at XTPL, a beneficiary of the FNP’s HOMING PLUS programme (2011).

ZBIGNIEW ROZYNEK, PhD, co-founder and main member of the technology team at XTPL, a beneficiary of the FNP’s HOMING PLUS programme (2013).