Lavi, IdoMeunier, NicolasVoituriez, RaphaëlCasademunt i Viader, Jaume2020-05-082020-05-082020-02-061539-3755https://hdl.handle.net/2445/159357We introduce a minimal hydrodynamic model of polarization, migration, and deformation of a biologicalcell confined between two parallel surfaces. In our model, the cell is driven out of equilibrium by an activecytsokeleton force that acts on the membrane. The cell cytoplasm, described as a viscous droplet in the Darcyflow regime, contains a diffusive solute that actively transduces the applied cytoskeleton force. While fairlysimple and analytically tractable, this quasi-two-dimensional model predicts a range of compelling dynamicbehaviours. A linear stability analysis of the system reveals that solute activity first destabilizes a globalpolarization-translation mode, prompting cell motility through spontaneous symmetry breaking. At higheractivity, the system crosses a series of Hopf bifurcations leading to coupled oscillations of droplet shape andsolute concentration profiles. At the nonlinear level, we find traveling-wave solutions associated with uniquepolarized shapes that resemble experimental observations. Altogether, this model offers an analytical paradigmof active deformable systems in which viscous hydrodynamics are coupled to diffusive force transducers.20 p.application/pdfeng(c) American Physical Society, 2020Cèl·lulesDinàmica molecularDinàmica de fluidsCellsMolecular dynamicsFluid dynamicsinfo:eu-repo/semantics/article6995092020-05-08info:eu-repo/semantics/openAccess