Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DY: Fachverband Dynamik und Statistische Physik
DY 52: Poster: Active Matter, Microswimmer, Microfluidics
DY 52.9: Poster
Donnerstag, 4. April 2019, 15:00–18:00, Poster B2
Polarization of Brownian swimmers with spatially heterogeneous activity — •Sven Auschra1, Nicola Söker2, Paul Cervenak1, Viktor Holubec1, Klaus Kroy1, and Frank Cichos2 — 1Institute for Theoretical Physics, University of Leipzig, 04103 Leipzig, Germany — 2Peter Debye Institute for Soft Matter Physics, University of Leipzig, 04103 Leipzig, Germany
Janus particles fuelled by laser heating are paradigmatic autophoretic microswimmers. Their dynamics under constant driving has been well characterized [1-3]. We consider situations in which the particles’ propulsion strength fluctuates in space and time, due to a variable fuel supply. Specifically, we analyze their spatial and orientational distribution experimentally, realizing prescribed spatial and temporal activity variations via the laser heating. We find depletion in regions of higher activity and polarization in activity gradients. Using Brownian dynamics simulations and a powerful numerical solver for Fokker-Planck equations [4], we can reproduce the experimental observations. A simple run-and-tumble process captures the observed features, qualitatively, and provides some analytical insights.
[1] A. Bregulla and F. Cichos: Faraday Discuss. 184, 381*391 (2015).
[2] H. Jiang, N. Yoshinaga, and M. Sano: PRL 105, 268302 (2010).
[3] A. Würger: Rep. Prog. Phys. 73, 126601 (2010).
[4] V. Holubec, K. Kroy and S. Steffenoni: arXiv:1804.01285v2 (2018).