Active particles in periodic lattices

Abstract

Both natural and artificial small-scale swimmers may often self-propel in environments subject to complex geometrical constraints. While most past theoretical work on low-Reynolds number locomotion addressed idealised geometrical situations, not much is known on the motion of swimmers in heterogeneous environments. As a first theoretical model, we investigate numerically the behaviour of a single spherical micro-swimmer located in an infinite, periodic body-centred cubic lattice consisting of rigid inert spheres of the same size as the swimmer. Running a large number of simulations we uncover the phase diagram of possible trajectories as a function of the strength of the swimming actuation and the packing density of the lattice. We then use hydrodynamic theory to rationalise our computational results and show in particular how the far-field nature of the swimmer (pusher vs. puller) governs even the behaviour at high volume fractions.

References in corpus (5)

• The hydrodynamics of swimming microorganisms
• Hydrodynamic attraction of swimming microorganisms by surfaces
• Fluid dynamics and noise in bacterial cell-cell and cell-surface scattering
• Ciliary contact interactions dominate surface scattering of swimming eukaryotes
• Geometric capture and escape of a microswimmer colliding with an obstacle

Cited by in corpus (2)

• Hydrodynamic Mobility Reversal of Squirmers near Flat and Curved Surfaces
• A Lattice Boltzmann Model for Squirmers