Anke LINDNER
Anke LINDNER
PMMH - ESPCI
From Individual Trajectories to Collective Motion in E-coli Bacteria
Wednesday, November 12, 2025
1:30 p.m. — ConfIV (E244)
From Individual Trajectories to Collective Motion in E-coli Bacteria
Abstract: Active fluids, composed of self-propelled particles such as bacteria or synthetic microswimmers, exhibit behaviors distinct from passive systems. Here, we investigate the transport of E. coli in confined microfluidic geometries, with and without imposed flow, using a Lagrangian 3D tracking method. Experiments and modeling reveal mechanisms underlying upstream swimming, lateral drift, and bacterial accumulation. At higher concentrations, collective motion emerges with characteristic vortex-like structures identified via PIV measurements. We analyze how confinement and concentration control the corresponding length scales. The insights gained offer strategies to manipulate bacterial transport in complex environments and to connect mesoscopic dynamics with macroscopic properties of active suspensions.