It is with great pleasure that we announce Amin Doostmohammadi (University of Copenhagen) as the recipient of the 2026 Soft Matter lectureship.
This award honours an early-career researcher who has made significant contributions to the soft matter research field. The recipient is selected by the Soft Matter Editorial Board from a list of candidates nominated by the community.
Find out more about Amin and his research in our interview below!
How has your research evolved from your first article to your most recent article?
My research has changed a lot in the specifics, but one thread runs through all of it: I’ve always been drawn to how the physics of fluids and interacting systems produces collective behaviour that one would not predict from the individual parts.
My first paper, during my PhD, was about low Reynolds number swimming in density-stratified fluids, how microorganisms move through water whose properties change with depth, and how that changes their swimming and transport. At the time I was thinking like a fluid dynamicist: hydrodynamic interactions, transport, how the fluid shapes the swimmer.
From there I got interested in systems where the moving components don’t just respond to the fluid around them but actively generate forces and flows themselves. That’s active matter. I became particularly interested in active nematics, polar active matter, and the role topological defects play in organising collective flows.
The move from active fluids to living systems then felt natural, because a tissue is, in its own way, an extraordinarily complicated active material. Cells generate forces, change shape, move, divide, and constantly read and respond to signals from their neighbours. I wanted to know whether the concepts built for active matter could actually explain these biological behaviours, or whether biology would just break them.
Today my research sits at that interface between active and living matter, combining theory, simulation and experiment to ask how mechanical interaction and cellular activity generate collective states, and how those states depend on the scale at which you look. Essentially, my research has moved further toward asking what new physics emerges when activity, mechanics and biological regulation are coupled. For example, we have studied how topological defects can concentrate mechanical stresses in active materials, and how cellular systems can display universal geometrical and dynamical behaviour despite their very different microscopic compositions.
I think that is the most exciting evolution for me. The starting point was essentially, “What does activity do to matter?” The question now is closer to, “What can activity allow living matter to do?”
What excites you most about your area of research, and what has been the most exciting moment of your career so far?
That physics can get real traction on phenomena that look, at first glance, uniquely biological.
Biology doesn’t fall from another reality. Living systems are extraordinarily complex, but they’re still physical systems, bound by the same laws as everything else. The genuinely hard part is figuring out which physical principles survive the jump from individual molecules and cells to collective biological behaviour, and which ones simply don’t apply anymore.
Active matter is a sharp tool for this because it’s built entirely around what happens when matter is driven out of equilibrium. Cells aren’t passive building blocks sitting around waiting to be pushed. They burn energy, generate their own forces, change shape, and constantly negotiate with their neighbours, and that produces collective behaviour that looks nothing like a passive material doing the same thing.
The moments in my career I remember most clearly are the ones where something that looked hopelessly complicated turned out to have one simple physical principle sitting underneath it, usually to do with topological defects and collective flows in active matter. More recently, the real thrill has been watching that same logic work in actual tissue, taking an idea born in active matter physics, finding it show up in a living system, then using experiment and theory together to explain why. That link between a fairly abstract piece of physics and something a cell is actually doing is, for me, the best part of the job.
In your opinion, what are the most important questions to be asked and answered in your field of research?
The biggest one, I think, is how collective function emerges from microscopic activity.
We’ve gotten quite good at describing how active matter moves, the mechanisms by which individual active components generate force, interact, and produce collective flow are increasingly well understood. Living systems ask something harder: how does a collection of active components use those same physical interactions to organise itself, make decisions, and hold a functional state together?
A closely related question is how information actually moves through living matter. In a tissue, information is almost never purely chemical or purely mechanical: a cell generates a force, that force changes its neighbours’ behaviour, those cells alter their signalling, and the biochemistry feeds back onto the mechanics. You end up with coupled flows of mechanical and chemical information running across many scales at once, and I think we’re still missing the physics vocabulary to describe that properly.
We also need better theory for systems that are permanently, structurally out of equilibrium. Equilibrium statistical mechanics gave us extremely powerful concepts for describing states and transitions between them; living systems never sit still long enough for most of that toolkit to apply cleanly. We need to know what replaces those concepts once probability currents, time-directed dynamics and active stress are baked into the system rather than being a perturbation on top of it.
How do you feel about Soft Matter as a place to publish research?
I’ve always thought of Soft Matter as a natural home for this kind of work.
Soft matter isn’t defined by a material or a technique, it’s a way of thinking about systems where mechanics, fluctuations, interactions and collective behaviour matter more than the specific substance involved. That makes it a genuine meeting point for physics, chemistry, engineering and biology, which matters a lot for active matter specifically: the same physical ideas turn up in a bacterial suspension, a cytoskeletal network, a synthetic active material, or a tissue, and having one journal where those communities actually run into each other is valuable in a way that’s easy to underrate.
I’ve also watched Soft Matter help active matter become a real part of the broader soft matter community over the last decade, creating space for ideas to move between disciplines that otherwise wouldn’t talk to each other. Some of my own work has appeared there across several stages of that arc, from active nematic flows and topological defects to active matter in complex environments and, more recently, collective behaviour in tissue.
Which of your Soft Matter publications are you most proud of and why?
“Density–velocity relation is scale-dependent in epithelial monolayers”
I’m proud of this one because it’s a good representation of what my lab is trying to do right now: treat experiment and theory as one continuous process rather than two separate activities that occasionally compare notes.
We started from a deceptively simple question: does higher cell density in an epithelial tissue suppress movement, or can dense regions actually become more active? Different experiments and theories had given apparently contradictory answers, and neither side was obviously wrong. What we found is that both are correct — it just depends on the spatial scale you’re looking at. At small scales, velocity increases with density; at larger scales, density suppresses movement. We combined live-cell imaging with traction force and stress measurements to pin down the mechanical origin of that crossover, then built a minimal theoretical model that reproduces it.
I like this paper because it captures something I think is genuinely fundamental to soft and active matter: properties that look contradictory can turn out to be entirely consistent once you identify the right scale to look at them. It’s also the direction I want the rest of my research to go in — experiment telling us what the living system is actually doing, theory telling us which parts of that are a general mechanism and which are specific to one system. That combination is where active matter earns its keep as a way of understanding living matter, rather than just describing it.
In which upcoming conferences or events (online or in person) may our readers meet you?
One event where readers can meet me in 2026 is the IUTAM (International Union of Theoretical and Applied Mechanics) Symposium on Active Fluids, taking place in Shenzhen in December. I am one of the confirmed invited speakers, and the conference is particularly close to my current interests because it brings together active matter physics, tissue mechanics, non equilibrium statistical mechanics and morphogenesis.
I am also involved in organising scientific meetings at the Niels Bohr Institute in Copenhagen, including the Copenhagen Days for Active Matter, which brings together researchers working on fundamental and biological aspects of active matter normally around April-May.
My conference schedule changes quite a bit, so the best way for readers to find me is probably through the soft matter community and the events surrounding active matter, biological physics and non equilibrium soft matter.
How do you spend your spare time?
Most of it goes to my wife and our daughter. Having a young child is a remarkably effective way of guaranteeing that work doesn’t quietly eat your entire life.
I also swim, it’s one of the few things that actually switches my brain off from research. You cannot answer emails or think about a paper while swimming, which is precisely the point. Research is consuming, and the best ideas often show up right when you’ve stopped actively hunting for them.
To learn more about Amin’s research, have a look at some of his recent publications in Soft Matter, which are FREE to access until 26 December 2026. You can also check out articles from our previous lectureship winners in our lectureship winners collection.
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Density–velocity relation is scale-dependent in epithelial monolayers
Hengdong Lu, Tianxiang Ma and Amin Doostmohammadi Soft Matter (2026) 22 (6): 1350–1357 |
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A spectrum of p-atic symmetries and defects in confluent epithelia
Lea Happel, Griseldis Oberschelp, Anneli Richter, Gwenda Roselene Rode, Valeriia Grudtsyna, Amin Doostmohammadi and Axel Voigt Soft Matter (2026) 22 (5): 1109–1129 |
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Elasticity tunes mechanical stress localization around active topological defects
Lasse Bonn, Aleksandra Ardaševa and Amin Doostmohammadi Soft Matter (2024) 20 (1): 115–123 |
We would like to thank everybody who nominated a candidate for the 2026 Soft Matter Lectureship. The Editorial Board had a very difficult task in choosing a winner from the many excellent and worthy candidates.
Please join us in congratulating Amin on winning this award!
