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We set ourselves a challenge to be the first to print a light source

Ludvig Edman displays a business card with a light bulb image. It might look ordinary, but it’s a culmination of many years of research. When he places the card against a standard card reader on the wall, like those for door access, the bulb illuminates.

What we are looking at is a light-emitting electrochemical cell (LEC) – a flexible, thin light source that combines an organic semiconductor and an electrolyte. In essence, it operates like a combination of a battery and a conventional light-emitting diode (LED). The scientific community was for a long time divided over how the technology functioned, but Ludvig Edman and his research colleagues were able to design and execute experiments that resolved this issue.

One of the advantages with the LEC is that it can be produced using environmentally friendly and inexpensive methods. It can be airbrushed directly onto complex surfaces or mass-produced by energy- and material-efficient printing and coating methods.

“We set ourselves a challenge to be the first to print a light source and make it available to the public and we did that in 2010,” says Ludvig Edman.

Elite sports require passion – as does research

When Ludvig Edman was younger, he was a dedicated runner. He participated in the European cross-country championships and 'trained all the time', as he describes it.

“Elite sports and research have many similarities. Both demand passion and endurance,” he says.

He was recently selected by the European Research Council (ERC) to receive the ERC Advanced Grant – a €2.5 million research grant awarded to the very best researchers in Europe.

Read more: Ludvig Edman rewarded for his bright ideas in research

“The importance of patience and overcoming adversity in research should not be underestimated. Often you pour time into ideas that you think are great, but after long and demanding investigations it turns out that they don't work out as you hoped. I have also spent a lot of weekends and evenings writing applications to fund our activities that were eventually rejected. In this way, it is reminiscent of competitive sports. You struggle and train but when the competition comes, you often don't reach the goal you want. But the only way forward is to analyze what could have been done better or smarter and try again. I have benefited a lot from this insight, but also from the fact that it is important to enjoy when things go well, and not to take anything for granted. Today, I make sure that our research group always celebrates when someone achieves a goal,” says Ludvig Edman.

Discovered the technology in the US

Semiconductors are foundational to all electronics, such as mobile devices and computers, and are traditionally made of inorganic materials, mainly silicon. Experimentation with organic (carbon-based) semiconductors began in the 1980s. The technology behind the LEC involves adding an electrolyte or ions – such as those found in batteries – to the organic semiconductor. In this way, the light-emitting structure can be made very thin and flexible.

The technology was invented in 1996 in Santa Barbara, California. After completing his doctoral studies in nearby Berkeley, Ludvig Edman heard about the project and, with his specialist knowledge of lithium batteries, he soon joined the research team.

Edman later returned to Umeå and continued his research. At the same time, interest in OLED displays, which have some similarities to LECs, began to take off and quickly grew into a billion-dollar industry. Many researchers also became interested in solar cells. But Ludvig Edman's group in Umeå remained committed to their fundamental research.

“I can be extremely stubborn, and I have chosen projects where I believe we can make a difference. I have realized that we are very good at what we are doing, but also that it would probably have been smarter from a funding point of view to focus on other things like OLEDs or batteries. But I have chosen to stay because I have felt that in those areas, I would just be one of many. Here I make a difference and that's what drives me,” says Ludvig Edman.

Metal-free light source attracted interest

In addition to being the first to print a light source, Ludvig Edman's research team was the first to develop a light source entirely without metal.

“When we announced it, it spread like wildfire and people contacted us from all over the world,” he says.

In 2012, he co-founded the company LunaLEC, which develops LEC technology for practical applications. These include blue-emitting soft blankets for home treatment of jaundice in newborns, eco-friendly designed indicator lights and safety solutions, and medicine packages that glow green or red depending on whether the patient has taken their medicine or not.

Recently, LEC has garnered more interest, especially considering the increasing importance of environmental and safety issues.

“Electronics are a concern because it is very difficult to recycle the environmentally and geopolitically difficult raw materials and since the production is energy intensive. Here we have a component that can be completely free of rare and toxic critical raw materials, and can be manufactured using energy-efficient and environmentally friendly methods. In an ongoing project, we are trying to test the limits in this context by developing an LEC from purely bio-based materials.”

When we announced that we had developed a light source entirely without metal, it spread like wildfire across the world

Thanks to the ERC Advanced Grant, Ludvig Edman will now be able to take the next step in his research and expand his group with new and highly skilled colleagues.

“Being a researcher has many upsides, with one being the role of a mentor. Every day I get to challenge, and be challenged by, intelligent and motivated young individuals who often go on to other roles, both in academia and beyond. It is always exciting to reconnect with former students and learn about their current endeavors. My research is very much a team effort, requiring many complementary skills, and I would like to emphasize that it is the hard work of my students and colleagues that made this recognition possible,” says Ludvig Edman.