Related Experiment Video
Updated: Feb 25, 2026

Quantitative Locomotion Study of Freely Swimming Micro-organisms Using Laser Diffraction
Published on: October 25, 2012
Role of Correlations in the Collective Behavior of Microswimmer Suspensions
Joakim Stenhammar1, Cesare Nardini2,3,4, Rupert W Nash5
1Division of Physical Chemistry, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
Abstract:
In this Letter, we study the collective behavior of a large number of self-propelled microswimmers immersed in a fluid. Using unprecedentedly large-scale lattice Boltzmann simulations, we reproduce the transition to bacterial turbulence. We show that, even well below the transition, swimmers move in a correlated fashion that cannot be described by a mean-field approach. We develop a novel kinetic theory that captures these correlations and is nonperturbative in the swimmer density. To provide an experimentally accessible measure of correlations, we calculate the diffusivity of passive tracers and reveal its nontrivial density dependence. The theory is in quantitative agreement with the lattice Boltzmann simulations and captures the asymmetry between pusher and puller swimmers below the transition to turbulence.
Related Concept Videos
Buoyancy and Stability for Submerged and Floating Bodies
Colloids and Suspensions
Correlation of Experimental Data
For example, a spherical particle moving through a viscous fluid experiences drag. Dimensional analysis shows that the drag force depends on the particle's diameter, velocity,...
Surface Tension of Fluid
Surface tension varies...
First Law: Particles in Two-dimensional Equilibrium
Newton's first law tells us about...
Coagulation

