Sedimentation, trapping, and rectification of dilute bacteria

By J. Tailleur, M. E. Cates. 2009

268 citations recorded by the source corpus.

The run-and-tumble dynamics of bacteria, as exhibited by E. coli, offers a simple experimental realization of non-Brownian, yet diffusive, particles. Here we present some analytic and numerical results for models of the ideal (low-density) limit in which the particles have no hydrodynamic or other interactions and hence undergo independent motions. We address three cases: sedimentation under gravity; confinement by a harmonic external potential; and rectification by a strip of “funnel gates" which we model by a zone in which tumble rate depends on swim direction. We compare our results with recent experimental and simulation literature and highlight similarities and differences with the diffusive motion of colloidal particles.

Subfields: Condensed Matter Physics, Materials Chemistry, Ocean Engineering

View Paper: https://www.semanticscholar.org/paper/5b336c0f19fcc3ed425bb945afe9745d6ff04012

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In Condensed Matter Physics

In Materials Chemistry

In Ocean Engineering

Citations in the corpus

Active Particles in Complex and Crowded Environments (2016, background): “However, for some specific classes of active particles analytic solutions can be found, and the traditional Boltzmann equation can also be generalized to some active systems (Schnitzer, 1993; Tailleur and Cates, 2008, 2009; Thüroff et al., 2013, 2014).”
Brownian motion of a self-propelled particle. (2010, background): “In addition to that, the model might be transferred to more complicated geometries [9, 68–70] and flexible particle shapes [71, 72].”
Lattice models of nonequilibrium bacterial dynamics (2010, methodology): “In this work we construct a lattice model whose non-interacting continuum limit recovers the off-lattice equations previously derived for non-interacting run-and-tumble particles [12, 14].”
A micrometre-sized heat engine operating between bacterial reservoirs (2016, background): “Further, exact solutions [15] to the Langevin equation for a self propelled particle in a harmonic trap suggests that the shape of P (∆x) is determined by parameter a = (2μkτc) −1, where μ is the mobility of the particle.”
The effective temperature (2011, background): “Other theoretical studies of TEFF in active matter appeared in [145].”
Pressure is not a state function for generic active fluids (2014, background): “, Self-propelled rods near surfaces, EPL 85, 38002 (2009) [32] Tailleur, J.”
Physics of microswimmers—single particle motion and collective behavior: a review (2014, background): “• Sedimentation in a gravitational field is also strongly affected by active propulsion (Enculescu and Stark, 2011; Tailleur and Cates, 2009).”
Nonequilibrium equation of state in suspensions of active colloids (2014, unknown): “These conclusions are far from trivial, as they do not hold for all types of active particles (run-and-tumble bacteria being a relevant counterexample [9]), while the mapping to an ideal gas may break down in more complex geometries even for self-propelled particles [10].”