Berlin 2018 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 16: Active Matter II (joint session DY/CPP/BP)
DY 16.4: Talk
Monday, March 12, 2018, 16:15–16:30, BH-N 243
Viscotaxis: a theory for microswimmer navigation in viscosity gradients — •Benno Liebchen1, Paul Monderkamp1, Borge ten Hagen2, and Hartmut Loewen1 — 1Institut fuer Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universitaet Duesseldorf, D-40225 Duesseldorf, Germany — 2Physics of Fluids Group, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands
The survival of many microorganisms, like Leptospira or Spiroplasma bacteria, which swim poorly in low-viscosity fluids, depends on their ability to navigate up viscosity gradients. While this ability, called viscotaxis, has been observed in several experiments with microorganisms, the underlying mechanism remains unclear. In the present talk, we present a simple theory for viscotaxis of self-propelled swimmers [1] in slowly varying viscosity gradients: this theory unveils specific mechanisms for viscotaxis based on a systematic imbalance of viscous forces acting on different body parts of a swimmer and allows to classify microswimmers regarding their ability to perform viscotaxis based on their body shapes. Besides shedding new light on microorganism viscotaxis, our results may be useful to design synthetic swimmers with the ability to navigate in viscosity gradients (akin to synthetic chemo- or thermotactic swimmers [2]).
[1] B. Liebchen, P. Monderkamp, B.t. Hagen and H. Löwen, in preparation.
[2] B. Liebchen, D. Marenduzzo, and M. E. Cates, Phys. Rev. Lett. 118, 268001 (2017).