Active Young-Dupré Equation: How Self-organized Currents Stabilize Partial Wetting

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Zhao, Yongfeng, Zakine, Ruben, Daerr, Adrian, Kafri, Yariv, Tailleur, Julien, van Wijland, Frédéric
Format: Preprint
Publié: 2024
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866910129581981696
author Zhao, Yongfeng
Zakine, Ruben
Daerr, Adrian
Kafri, Yariv
Tailleur, Julien
van Wijland, Frédéric
author_facet Zhao, Yongfeng
Zakine, Ruben
Daerr, Adrian
Kafri, Yariv
Tailleur, Julien
van Wijland, Frédéric
contents The Young-Dupré equation is a cornerstone of the equilibrium theory of capillary and wetting phenomena. In the biological world, interfacial phenomena are ubiquitous, from the spreading of bacterial colonies to tissue growth and flocking of birds, but the description of such active systems escapes the realm of equilibrium physics. Here we show how a microscopic, mechanical definition of surface tension allows us to build an Active Young-Dupré equation able to account for the partial wetting observed in simulations of active particles interacting via pairwise forces. Remarkably, the equation shows that the corresponding steady interfaces do not result from a simple balance between the surface tensions at play but instead emerge from a complex feedback mechanism. The interfaces are indeed stabilized by a drag force due to the emergence of steady currents, which are themselves a by-product of the symmetry breaking induced by the interfaces. These currents also lead to new physics by selecting the sizes and shapes of adsorbed droplets, breaking the equilibrium scale-free nature of the problem. Finally, we demonstrate a spectacular consequence of the negative value of the liquid-gas surface tensions in systems undergoing motility-induced phase separation: partially-immersed objects are expelled from the liquid phase, in stark contrast with what is observed in passive systems. All in all, our results lay the foundations for a theory of wetting in active systems.
format Preprint
id arxiv_https___arxiv_org_abs_2405_20651
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Active Young-Dupré Equation: How Self-organized Currents Stabilize Partial Wetting
Zhao, Yongfeng
Zakine, Ruben
Daerr, Adrian
Kafri, Yariv
Tailleur, Julien
van Wijland, Frédéric
Soft Condensed Matter
Statistical Mechanics
The Young-Dupré equation is a cornerstone of the equilibrium theory of capillary and wetting phenomena. In the biological world, interfacial phenomena are ubiquitous, from the spreading of bacterial colonies to tissue growth and flocking of birds, but the description of such active systems escapes the realm of equilibrium physics. Here we show how a microscopic, mechanical definition of surface tension allows us to build an Active Young-Dupré equation able to account for the partial wetting observed in simulations of active particles interacting via pairwise forces. Remarkably, the equation shows that the corresponding steady interfaces do not result from a simple balance between the surface tensions at play but instead emerge from a complex feedback mechanism. The interfaces are indeed stabilized by a drag force due to the emergence of steady currents, which are themselves a by-product of the symmetry breaking induced by the interfaces. These currents also lead to new physics by selecting the sizes and shapes of adsorbed droplets, breaking the equilibrium scale-free nature of the problem. Finally, we demonstrate a spectacular consequence of the negative value of the liquid-gas surface tensions in systems undergoing motility-induced phase separation: partially-immersed objects are expelled from the liquid phase, in stark contrast with what is observed in passive systems. All in all, our results lay the foundations for a theory of wetting in active systems.
title Active Young-Dupré Equation: How Self-organized Currents Stabilize Partial Wetting
topic Soft Condensed Matter
Statistical Mechanics
url https://arxiv.org/abs/2405.20651