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BP: Fachverband Biologische Physik
BP 5: Active Biological Matter II (joint session BP/CPP/DY)
BP 5.1: Talk
Monday, March 22, 2021, 11:00–11:20, BPb
Chiral stresses in nematic cell monolayers — •Ludwig A. Hoffmann1, Koen Schakenraad1,2, Roeland M. H. Merks2,3, and Luca Giomi1 — 1Instituut-Lorentz, Leiden University, The Netherlands — 2Mathematical Institute, Leiden University, The Netherlands — 3Institute of Biology, Leiden University, The Netherlands
Recent experiments on monolayers of spindle-like cells have provided a convincing demonstration that certain types of collective phenomena in epithelia are well described by active nematic hydrodynamics. While recovering some of the predictions of this framework, however, these experiments have also revealed unexpected features that could be ascribed to the existence of chirality over length scales larger than the typical size of a cell.
We elaborate on the microscopic origin of chiral stresses in nematic cell monolayers and investigate how chirality affects the motion of topological defects, as well as the collective motion in stripe-shaped domains. We find that chirality introduces a characteristic asymmetry in the collective cellular flow, from which the ratio between chiral and non-chiral active stresses can be measured. Furthermore, we find that chirality changes the nature of the spontaneous flow transition under confinement and that, for specific anchoring conditions, the latter has the structure of an imperfect pitchfork bifurcation.