Berlin 2018 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 59: Microswimmers II (joint session DY/CPP/BP)

DY 59.1: Talk

Thursday, March 15, 2018, 10:00–10:15, BH-N 243

Dynamical density functional theory for swarms of active microscopic circle swimmers — Christian Hoell, Hartmut Löwen, and •Andreas M. Menzel — Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany

The study of self-propelled particles and active microswimmers is an intensely growing field. However, mostly straight-propelling objects are addressed. In contrast to that, typical real objects are imperfect and show persistently bent trajectories, as investigated in the present case.

Recently, we introduced a first dynamical density functional theory to describe swarms of straight swimming microswimmers suspended in a fluid [1]. The theory includes all basic ingredients, namely, self-propulsion, hydrodynamic as well as steric interactions between the swimmers, and confinement by external potentials. We have now extended this theory to statistically characterize the collective behavior of microscopic circle swimmers [2].

To illustrate the statistical consequences of circle swimming [2], we consider confinement by a spherical trap. While straight-swimming objects tend to push outward against the confining barriers and only by spontaneous symmetry breaking collectively move around the trap, circle swimmers show a deterministic tendency of rotating around the confinement. An increasing tendency of circle swimming leads to localization of the swimmer density in the center of the trap. We have investigated both pusher- and puller-type swimming mechanisms.

[1] A. M. Menzel et al., J. Chem. Phys. 144, 024115 (2016).

[2] C. Hoell et al., New J. Phys. in press (2017).