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Professor Jussi Toppari is an expert in nanophysics and nanotechnology. He leads his own research team specialised in molecular electronics and plasmonics, which studies and develops new nanomaterials that take advantage of the self-organisation of DNA molecules. By means of self-organising DNA molecules, it is possible to make various new structures, the active components of which are in the scale of about ten nanometres. These enable, for example, realising a totally new kind of optic materials.

“We aim at developing new optically active structures as well as fast and inexpensive ways to make so-called metamaterials,” says Toppari. “Metamaterials are artificial materials that have interesting new special properties different from usual natural materials. They may someday enable optical signal processing in structures below the diffraction limit and thus fully optical information technology, for example, which would be much faster than the electronic one.”

Ecologically more sustainable solutions

Toppari searches for ways to use nanomaterials for zero-emission energy systems as well as for solutions to other environmental problems. For example, one of Toppari’s research projects seeks to replace toxic catalysts used in the chemical industry.

“We aim to modify the chemistry of molecules by coupling them to confined electromagnetic radiation, such as visible light, for instance,” Toppari explains. “The confinement of radiation is accomplished by means of the nanostructures we produce. The so-called polariton formed upon the strong coupling alters the energy states of the molecules and thus their properties. With these new methods, we may be able in the future to replace some of the catalysts used in chemical industry. Polaritons also enable extremely fast and efficient energy transfer, which can be applied to the collection of solar energy, for example. All new inventions like this will help us in the green transition.”

Research field changed, interest stayed

Toppari has always been interested in physics. After graduating from Heinola Lyseonmäki Upper Secondary School, he applied for a study place in Jyväskylä and in Helsinki. Of the two cities, he chose Jyväskylä. His master’s thesis in applied physics was completed on schedule in 1997, after which doctoral studies followed right away in Jyväskylä. He started his postgraduate studies in Professor Jukka Pekola’s research team, studying quantum mechanical tunnelling phenomena in metal nanostructures. Toppari completed his PhD in 2003 and decided to change his research field.

“Before establishing my own research team, I got acquainted with the diverse possibilities of DNA while I was working in Professor Päivi Törmä’s research team,” Toppari says. “Then the electric conductivity of DNA was a hot topic and that started to guide my own research as well. Nanoscience was also a hot topic and the university’s new Nanoscience Center was just accomplished. In this environment, I became increasingly interested in cross-disciplinary approaches.”

Toppari’s own research field started to grow stronger along with the Academy Research Fellowship in 2009, when he established his own research team and started to study metamaterials more extensively. Toppari’s homebase has always been in Jyväskylä, but he spent six months in Germany (Leibniz Institute of Photonic Technology, IPHT, Jena). They still have close collaboration with the institute. From 2018 to 2021 Toppari chaired Jyväskylä International Summer School and was also a member of the University Collegium. Similarly, from 2018, he has been a member of the Nanoscience Center’s executive group and in charge of education curriculum in Nanoscience, and since last year, also the scientific vice director of the center.

Cross-disciplinary thinking

Doing research is at Toppari’s heart, which motivates him to come to work every day. Also, international collaboration is vitally essential to him.

“If there is no interest in deeper consideration of matters or finding solutions, there is also no reason to assume any new insights to appear,” Toppari says. “One’s thinking broadens when one meets a large variety of different researchers from across the world, who are interested in the same topic.”

Teaching also makes Toppari’s workdays rewarding. Development of teaching is important since Toppari wants to raise students’ interest for the field, both in the present and future students.

“My goal is not, however, that all students would be interested in nanotechnology, in particular, but I especially hope to develop their cross-disciplinary thinking,” Toppari states.

Strong team spirit in the faculty

The open atmosphere and teamwork are the best part of the JYU Faculty of Mathematics and Science. Help is always available when needed.

“Especially in the Nanoscience Center, close joint effort is highlighted when people are working on the similar targets of interest,” Toppari says. “You can always discuss with someone about a problem that’s come up and related ideas for solutions.”

Music at leisure

Life is not merely research and teaching, however. Music has always been important to Toppari, and he spends his free time both with his own and with his son’s band. Musical and research activities have much in common as both call for creativity and innovation.

“My big ambition is of course a grand world tour with my actively gigging band Whipping Post. It might happen when I’m already retired, if ever, I guess, but we all need to have dreams,” Toppari laughs.

Further information:

• Professor Jussi Toppari, j.jussi.toppari@jyu.fi, +358 40 805 4123
• Research team’s website: /science/en/physics/research/materials-physics/molecular-electronics-and-plasmonics