2026-04-13T16:47:41Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1938672025-12-04T20:47:11Zcom_2072_1057col_2072_478822col_2072_478914col_2072_478917

00925njm 22002777a 4500 dc Scagliarini, Andrea author Pagonabarraga Mora, Ignacio author 2023-02-20T16:05:06Z 2023-02-20T16:05:06Z 2022-06-06 2023-02-20T16:05:06Z The sedimentation process in an active suspension is the result of the competition between gravity and the autonomous motion of particles. We carry out simulations of run-and-tumble squirmers that move in a fluid medium, focusing on the dependence of the non-equilibrium steady state on the swimming properties. We find that for large enough activity, the density profiles are no longer simple exponentials; we recover the numerical results through the introduction of a local effective temperature, suggesting that the breakdown of the Perrin-like exponential form is a collective effect due to fluid-mediated dynamic correlations among particles. We show that analogous concepts can also fit the case of active non-motile particles, for which we report the first study of this kind. Moreover, we provide evidence of scenarios where the solvent hydrodynamics induces non-local effects which require the full three-dimensional dynamics to be taken into account in order to understand sedimentation in active suspensions. Finally, analyzing the statistics of the orientations of microswimmers, the emergence of a height-dependent polar order in the system is discussed. Hidrodinàmica Microorganismes Matèria condensada tova Hydrodynamics Microorganisms Soft condensed matter Hydrodynamic and geometric effects in the sedimentation of model run-and-tumble microswimmers