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  • Nea Alanen

How an innocent error turned into a notable invention

One unintentionally contaminated research sample led Aaretti Kaleva on an interesting life path. The research error turned out to be an unexpected invention of a new, sustainable, and environmentally friendly nanocoating innovation.


Aaretti Kaleva

Smooth. That is the word Aaretti Kaleva, 30-year-old Doctor of Science, uses to describe his doctoral studies in DSII. He is one of the students, who did their dissertation straight after accomplishing their master’s thesis.

Kaleva graduated on 12/03/2021 and did his doctoral dissertation in collaboration with the steel producer company SSAB Ab.




And what was that error mentioned above?

Kaleva was doing his master's thesis at Tampere University and working as a research assistant in a separate project where they studied galvanized metal sheets and the modification of their paint layers.


“I wasn’t involved in this research project from the very beginning. We did tests with a certain research machine. During these tests, we noticed that something happened that was not supposed to happen. There was an impurity in the machine. Somehow water had gotten inside. Later we discovered that the reaction with water and the samples in the machine formed something interesting that we did not expect.”


Sounds cryptic? Well, it was that for the people involved as well. The research group did not know what it was all about. With the above-mentioned water-involved error some kind of structure had formed on the metal sheets.


“We didn’t know what had happened, or if it was of use at all. We started brainstorming and wondering how we could grow the possibility of this error to re-appear.”


Kaleva started to investigate the matter alongside his master’s thesis. At some point, Kaleva’s professor Erkki Levänen said that it would be interesting to do a bit more research on the subject.


“I was already graduating when my professor recommended that I should apply for doctoral school.”


Antti Markkula at SSAB decided that a dissertation on this innovation should be done. So Kaleva started his doctoral work in 2017. He describes that the whole journey through the research process went without greater challenges, smoothly.


“Everything went really well, and it was an interesting experience to make my dissertation. I gained a lot of knowledge about writing and managing research assistants. I also learned to work independently – which I think is of great use.”



Research work for innovating a new product


Kaleva’s dissertation was focused on the functionalization of galvanized surfaces and developing a new synthesis method for Zinc Oxide nanowires by using supercritical carbon dioxide.


Difficulties to understand? Let’s put it vernacularly.


There are galvanized metal sheets, which means that you put zinc on top of steel so that the steel would have better corrosion resistance. In that way, the metal lasts for much longer in outdoor conditions. The other reason for galvanizing is that consumers usually want their metal roofs and other products in a variety of colors so the surface needs to be painted. The zinc surface is not best for the paint layer as the paint won’t stick very well. But it can be done.


Painted steel. Photo: SSAB ©

“SSAB has their own processing for metal sheets. They put this chemical on the galvanized surface for it to hold the paint better.”


The error in the research sample mentioned earlier produced a coating that would bring the same advantage as the chemical treatment. The thing is that the accidental way would be much more environmentally safe, and sustainable as the zinc oxide surface is created with only water and carbon dioxide. It is also much faster.


The structure which had formed because of the error during the research was actually something like the chemical treatment done by SSAB with strong chemicals. It was a nanocoating composed of zinc carbonates.


“This method is very environmentally friendly compared to these strong chemicals used by SSAB, so it won’t bring problems safety-wise or by passing chemicals into the environment.”

The question was: What if this chemical processing could be replaced with an environmentally safe and sustainable option?


That is what Kaleva’s dissertation was all about, vernacularly: To investigate this new innovation, and to solve if it could actually be used in the manufacturing process of galvanized metal sheets.


The preliminary tests have been promising. The invention could possibly be used for its purpose, but of course, the testing is still going on maybe for years to come.


Something else came up too

Kaleva and his assistants noticed another useful quality in this new invention.


“The structure which grew on the galvanized surface due to carbon dioxide and water wasn’t flat, but it was three-dimensional. It had spikes and other forms which grow the surface area much wider than if it were just flat.”

According to Kaleva, this quality is very convenient in some semiconductor applications.

The zinc oxide is formed on the surface of zinc after creating the artificial patina with carbon dioxide and then heating it in the oven. When this semiconductor, zinc oxide, is formed on the surface of the metal, it has many different qualities. For example its interaction with light. When the light touches the surface it reacts in a certain way. As the surface is larger with the nano-coating than on just a flat area, it has more surface to react with.


“That is why a nanostructure like this is so useful. Zinc oxide can be used for example in solar cells. In that use too, it is very inexpensive.”



A long way from invention to an actual product


Though the research has been quite successful it takes many more tests and even more research to bring the invention into the level of an actual product for SSAB to be utilized.

“My supervisor from SSAB says that the launch of a new product takes usually from 5 to 10 years. It’s a long process.”

Kaleva reveals that he still works a little bit at the university and has been making more test samples for SSAB. Very soon he will introduce his research results to the whole Swedish-Finnish product development group of SSAB, who owns the patent for this invention.


The four years of DSII


Everything went accordingly. No big problems or difficulties with Kaleva’s dissertation work. At the end of the year 2019, while still studying at the doctoral school, he started working for a start up company ColloidTek.


“It was really tough to do two very different kinds of works at the same time, but it was also very conducive. Doctoral student skills are always a great asset, but you won’t learn all the ways of working that you would learn working in a company. That’s why I recommend start ups also for doctoral students.”


At DSII Kaleva met, in his own words, many inspirational people and got decent peer support from the roundups at the university.


“For example, Tamlink arranged many good speakers on many important subjects for us. One good example is European patent attorney Harri Koivisto who came to lecture us about patenting. This was very useful at that time as we were just patenting this new innovation with SSAB.”


The collaboration with SSAB worked very well. The subject of the dissertation was such that you could easily do another dissertation out of it.


“All and all I think my ability to analyze and to deduce got much better during my DSII studies. I’ve also learned about supervising which has been useful to me.”


Kaleva thinks that dealing with many kinds of people and organizations along his DSII studies has taught him various ways of working. You never know what happens in life, but one should never underestimate the value of an error.





Read Aaretti Kaleva's dissertation here.