Wednesday, September 3, 2025
12:00 - 14:00
12:30 - 12:50 - Bram Hoogland, PhD Candidate, Physics of Living System, VU Amsterdam
Broadly applicable data-driven framework reveals non-reciprocal interactions in collective cell migration
Abstract: Learning the local interactions that generate emergent collective behavior remains a central challenge in active and living matter. Here we introduce a general data-driven inference framework to learn the dynamical interaction rules underlying the collective dynamics of a stochastic system directly from experimental trajectory data. Applying this approach to collectively migrating human cells confined to one-dimensional micropatterns, we reconstruct minimal many-body stochastic equations of motion for a broad range of distinct cell types: noncancerous epithelial MCF10A, fibrosarcoma mesenchymal-like HT1080, and mesenchymal breast cancer-derived MDA-MB-231. We find that while healthy epithelial cells coordinate through reciprocal repulsion and velocity alignment, the cancerous mesenchymal cells also rely on non-reciprocal interactions that couple contact to self-propulsion: contact-induced deceleration in fibrosarcoma cells and contact-induced acceleration in breast cancer cells. These non-reciprocal terms modulate both the onset and speed of flocking, revealing an important role for active interactions that violate action–reaction symmetry in multicellular migration. These novel interactions enable distinct migration behaviors absent in healthy epithelial cells, and may contribute to cancer cells’ enhanced ability to migrate and invade tissues. In general, our approach offers a broadly applicable route to uncovering the interaction laws in all kinds of many-body systems.
12:50 -13:45 - Erik C. Garnett, AMOLF, Amsterdam, the Netherlands
The Material Evolution Revolution
Abstract: Traditionally we design materials with exactly the properties we want and try to make them stable for decades – we intentionally avoid mutations. This means that we avoid degradation processes like rusting, cracking and warping, but we also exclude the possibility that materials improve over time or adapt to their environment. The idea of a bridge becoming more stable or a computer becoming faster with use may sound absurd, but such performance enhancements over time are a hallmark of biological evolution. We are not surprised now that AI models become better over time and even design them to evolve and improve, so why don’t we take such an approach with materials and devices? This lecture outlines the requirements for such evolvable materials and proposes spatiotemporal patterning of light as a tool to direct the evolution. It looks at two easily mutable systems – metal nanoparticles and halide perovskite semiconductors – as platforms to study material evolution. I will highlight the ways that light can both control and measure the properties of these materials in space and time. I will then show several examples of adaptable, self-optimizing and (re)programmable functions in photovoltaics, optics and catalysis and our first results on materials that display memory and elements of learning. I will end with my vision for the material evolution revolution and the exciting possibilities it presents.
Biography
Erik Garnett studied chemistry at the University of Illinois at Urbana-Champaign, USA, and obtained his PhD at the University of California at Berkeley. After his PhD he became a postdoctoral fellow at Stanford University, where he became acquainted with photonics, photovoltaics and plasmonics. He made the integration of nanophotonics with nanomaterials the prime goal of his research when he started his own independent academic career at AMOLF in 2012. There, he is one of the pioneers in understanding light-matter interactions in nanoscale solar cells, using well-controlled model systems and advanced nano-characterization techniques in order to answer the most pressing materials chemistry questions. His work leads to applications in solar cells, LEDs and light-driven chemical reactions. Since 2017 he is also professor of Nanoscale Photovoltaics at the University of Amsterdam. In 2022 he received the KNCV gold medal, given annually to one outstanding chemist under 40 working in the Netherlands.
VU
Vrije Universiteit, VO Research Building
Spectrum 5
Colloquium
complexity
Erik C. Garnett