Preventing clustering of active particles in microchannels

The trajectories of microswimmers moving in narrow channels of widths comparable to their sizes are significantly altered when they encounter another microswimmer moving in the opposite direction. The consequence of these encounters is a delay in the progress of both swimmers, which can be conceptua...

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Detalles Bibliográficos
Autores: Carrillo-Mora, Juan Pablo, Pires Monteiro, Moniellen, Marconi, V. I., Cordero, María Luisa, Brito López, Ricardo, Soto, Rodrigo
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/125803
Acceso en línea:https://hdl.handle.net/20.500.14352/125803
Access Level:acceso abierto
Palabra clave:53
539.1
Escherichia-coli
Bacterial
Glass
PDMS
Física (Física)
Partículas
22 Física
2207 Física Atómica y Nuclear
Descripción
Sumario:The trajectories of microswimmers moving in narrow channels of widths comparable to their sizes are significantly altered when they encounter another microswimmer moving in the opposite direction. The consequence of these encounters is a delay in the progress of both swimmers, which can be conceptualized as an instantaneous effective backward displacement. Similarly, the modeling of tumble events in bacteria, which occur over a finite time, can be represented as an instantaneous effective displacement in addition to a change in direction. Such effective displacements can be incorporated directly into a kinetic theory for the partial densities of swimmers moving in the channel. The linear analysis of the resulting equation yields the critical density at which clusters emerge. The methodology is then applied to the case of soil bacteria moving in long channels of cross-section 1.8 μm × 1.8 μm. The tracking of the swimmers permits the straightforward acquisition of the effective displacements, which in turn allows the critical density (ρcrit ≃ 0.10 bact/μm) to be predicted prior to cluster formation. The advantage of this proposed approach is that it does not necessitate the determination of an effective density-dependent speed, which is a requisite of the standard motilityinduced phase separation theory.