San Francisco – June 16, 2026

By Sarah Burckhardt Academic Engagement Program Manager, Swissnex in San Francisco

We often hear about the “Great Pacific Garbage Patch,” but the most dangerous plastic pollution is the kind we can’t see. Swiss researcher Dr. Roman Lehner is changing that. By bridging the gap between the rigorous analytical labs of the University of Bern and the worldwide expeditions of his association, Sail & Explore, Roman has developed a world-first methodology to fabricate, collect, and track micro- and nanoplastics.

During Climate Week 2026, Roman brought his dual approach of high-tech Swiss lab analysis and practical innovation and citizen science to the Bay Area, and literally into the San Francisco Bay. In this conversation with Sarah Burkhardt, Academic Engagement Program Manager for Swissnex in San Francisco, Roman discusses the “Silicon Valley vibe” of environmental action, why size matters when it comes to plastics in our environment, and how the ocean acts as a universal language connecting us all—even those of us living far from the ocean.

The interview has been condensed and edited for clarity. It was conducted on April 24, 2026 at Swissnex in San Francisco.

Sarah Burkhardt: Tell me about your research at the University of Bern and the association Sail & Explore. What are you trying to accomplish?

Roman Lehner: For both the University of Bern and Sail & Explore we try to make the invisible plastics visible. We aim to set up long-term monitoring studies in detecting microplastics, invisible microplastics, below 0.3 millimeter, on a global scale. And we are trying to implement long term studies to come up with really accurate and solid data. We would like to understand how much of this invisible plastic is in the environment and whether, with this data, we can also then push this towards a human health risk assessment.

From the University of Bern’s side, we also tackle, or try to make the invisible plastics visible, but in a different way. So the approach we have from the University of Bern is that we produce or fabricate micro and nano plastic particles out of bulk plastic products with a focus on food packaging and pharmaceutical packaging. And these micro and nano plastics that we produce in a very unique way can then be used for contamination studies, the very first global contamination studies to understand how much plastic, micro and nano plastic, can be found in specific food types and pharmaceuticals.

SB: How do you define micro and nano plastic?

RL: On one side, it’s obvious. So there are these words micro and nano, right? It might be misleading specifically for the “micro” plastics because we have the word “micro” but at the end, these plastics are, by definition, starting at the five millimeter range down to one micron, while the nanoplastic is everything below this one micron.

And what is very important for everyone to understand is that nanoparticles, so not just nanoplastics, but nanoparticles in general, behave differently than a microplastic. And we already know, there is already proof that nano plastics, as well as nano particles in general, can be taken up by humans but also plant cells, while micro plastic cannot. And this is really very important. So size really does matter, if you look at these plastics.

SB: What is interesting with your work is that it is within the traditional academia environments, University of Bern, but you also have your own association, Sail & Explore. How did this joint mission come together? And why is your work more impactful by having two organizations?

RL: Sail & Explore was founded before I joined the University of Bern. I went to University of Bern with a very clear idea, because I wanted to produce these micro, nano plastic particles, because I already did some research on that and I set up a project a with a focus on food packaging and pharmaceuticals, and to try, for the very first time, to make micro and nano plastics out of bulk plastics.

So the interesting aspect now is that the work of Sail & Explore has several components. On one side, we do citizen science research and field work. So we go out and collect samples in the open ocean, but also in fresh water lakes, for example, in Switzerland, to collect those plastics and understand how much plastic is in there. And we make it open to the public, to citizen scientists to join us on our mission, to understand how we do it, to educate them, to train them, not only in how to collect those samples, but also train them in how to sail and connect them with nature.

However, at the end, whatever we collect with Sail & Explore needs to be further analyzed, and this analysis needs a proper lab setting, and obviously [Sail & Explore does] not have this because we use specific devices which are very expensive and only available at universities. And we are very fortunate because all Swiss universities offer a lot of different opportunities to do different tests. They’re well equipped.

SB: So University of Bern provides this research lab so you can really do this kind of deep analysis, and Sail & Explore is where you do a different kind of scientific expedition which also has an educational approach.

RL: Exactly. And the nice thing also is that when we reach out with Sail & Explore, it offers much more attractive outreach opportunities to communicate the problem, while the work of University of Bern is very analytical based, more business based, and so it’s a much nicer and cooler way of approaching a more public audience. In my view, it is something to do for raising awareness about pollution.

When people ask me, What do you think is the most important thing that everyone can do, or should we do? And I always say, education, because if you educate people at an early age, then they start to understand. And obviously, in Switzerland, you should not always talk about the ocean and plastic, but rather use examples within Switzerland. It doesn’t matter where we are, plastic is everywhere, and there are examples all over. You just need to pick them and learn how to communicate them and show it to the kids.

SB: What are you doing that is an innovation in this space?

RL: Well, obviously, in the work that we do, or that I do at University of Bern, we came up with a very innovative approach to produce these micro, nano plastics. It’s very unique. No one did that before us. Not only in how we can fabricate those materials, but also the full workflow, because it’s a lot of small puzzle pieces that we have created and that we can align next to each other that make the full picture. And that’s really cool, because this is exactly our strength that no one else out there is doing.

And with innovation with Sail & Explore we’re always trying to push the limits with Sail & Explore and we try to not take things for granted. We also established a new sampling methodology that enables us to sample down to several micron sizes regarding the size of the plastics that we collect, which no one has done before us. We can tackle this and go further down size-wise. We are also working on innovative approaches with other new sampling technologies. We’re not only collecting plastics at the surface, but also at specific depths, because that’s a very different situation. All the plastic research is connected to surface plastics –– plastics floating on the surface. But there’s almost no data available about plastics at five meters depth. And obviously, if you dig further down, then there is literally nothing available data-wise.

SB: We are speaking together at Swissnex in San Francisco. Today we brought you into a room with a broad range of professionals to showcase your work. You were in the Bay Area for almost one week. You met different kinds of people. What did you learn from them? Did you have any surprises?

RL: It was a very interesting week.The vibes here in America are slightly different than Europe and specifically Switzerland. People here are extreme, proactive and open minded, and really trying to push new ideas and test them out. And that was great to see.

We met up with a huge number of people with different backgrounds. And the nice thing was that everyone literally already came up with a possible idea for a future collaboration, or maybe an investment strategy or something else. You have an audience who is happy to have you and does see potential, and is very proactive. And it’s very cool.

I think this is definitely very unique here to the Bay Area, and you can really feel those vibes that people want to go for a change. And maybe it’s also the combination with climate week that is taking place, and we are part of this climate week, and it’s been a fantastic opportunity.

SB: What you are looking for in the next stage of your research, what can we keep an eye out for?

RL: We are definitely looking forward to connecting further with new partners we have reached out to researchers at the University of the Maldives, and also to OIST, the Okinawa Institute of Science and Technology. And we also got back to our partners in Australia. So we are very much looking forward to this. So that’s definitely very exciting. And just in general, it’s great to see where we are, how much positive feedback we get after all these years of investment with Sail & Explore.

And we are partnering quite often with very big organizations like the European Marine Observation and Data Marine Network, our marine data network, NOAA, here within the US. And it’s great. Not everyone gets these opportunities right? And so it really pays off that you put in a lot of hard work into that. And we are definitely looking forward to exploring new territory with Sail & Explore. That’s why there is the word “explore” in the name of the organization.

And it’s fantastic to see how the ocean, which covers around 80% of our planet, is connecting us all. It’s kind of like the Esperanto language, right? We all do have a different cultural background, but at the end of the day, the ocean connects us all, no matter if you’re from a landlocked country or not.

Roman Lehner is Co-Founder and Scientific Project Leader of the Sail & Explore Association and a Principal Investigator at the University of Bern in Switzerland.

Sarah Burckhardt is the Academic Engagement Manager at Swissnex in San Francisco.