Living Matter

Collective movement can be observed throughout the living world, from bacterial colonies and tissue cells to schools of fish and flocks of birds. Despite the significant biological differences among these systems, they exhibit similar patterns and dynamics, suggesting universal principles independent of microscopic details.

Updates

👆New preprint is on ArXiv!

We’re exploring how defects form and disappear in active living matter, like bacteria and epithelial cells. Our findings show irreversible half-integer defects that break spatial symmetry, challenging active nematic theory. arXiv:2508.15622v1

Join us for exciting opportunities:

We have funded positions for MSc, and PhD candidates to explore the physics of multicellular organization, develop advanced microscopy, and image analysis methods (more details).

Research

About the Lab

We focus on how tissues shape themselves and the mechanisms behind morphogenesis. By comparing experiments with theory, we’re uncovering the fundamental physics that govern how multicellular groups organize across various living cells. We’re also developing techniques to measure and control the organization of these structures, using microscopy, microfabricated environments, and image analysis algorithms.

Research topics

Collective cell dynamics & Multicellular self-shaping
Structure - Dynamics - Function interplay in cellular tissues
Experimental methods for characterization of multicellular properties
Optical methods for live cell imaging
Microscopy & Image analysis automation for cell imaging

Publications

Topological defects in multi-layered swarming bacteria

V. Yashunsky, D. J. G. Pearce, G Ariel, A. Be'er, Soft Matter, (2024), arXiv:2401.05560

Chiral edge current in nematic cell monolayers

V. Yashunsky, D. J. G. Pearce, C. Blanch-Mercader, F. Ascione, P. Silberzan and L. Giomi, Physical Review X, (2022) 12, 041017, arXiv: 2010.15555

☞ video1 ☞ video2

Crisscross multilayering of cell sheets

T. Sarkar, V. Yashunsky, L. Brézin, CM. Mercader, T. Aryaksama, M. Lacroix, T. Risler, JF. Joanny, P. Silberzan, PNAS Nexus, (2023), 2(3), 034, bioRxiv: 2021.06.22.449403

Turbulent Dynamics of Epithelial Cell Cultures

Blanch-Mercader C, Yashunsky V, Garcia S, Duclos G, Giomi L, and Silberzan P.

Physical Review Letters (2018), 120, arXiv:1711.01568

Spontaneous shear flow in confined cellular nematics

Duclos G, Blanch-Mercader C, Yashunsky V, Salbreux G, Joanny JF, Prost J and Silberzan P, Nature Physics, (2018) 14

☞ Live streaming, Francesc Sagués (News & Views)

Controlling Confinement and Topology to Study Collective Cell Behaviors

Duclos G, Deforet M, Yevick H, Cochet-Escartin O, Ascione F, Moitrier S, Sarkar S, Yashunsky V, Bonnet I, Buguin A, Silberzan P., Cell Migration. Methods in Molecular Biology, (2018), 1749: 387-399, Humana Press, New York, NY