Dresden 2017 – wissenschaftliches Programm
CPP 44.14: Vortrag
Mittwoch, 22. März 2017, 18:30–18:45, HÜL 186
Patterns in chemically interacting microswimmers: Do they really exist? — •Benno Liebchen1, Davide Marenduzzo1, and Michael E. Cates2 — 1SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom — 2DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 0WA, United Kingdom
Chemotaxis is the directed motion of particles in response to a gradient in a chemical signal. It allows micro-organisms, like bacteria, to find food and to escape from toxins. Some micro-organisms can produce the species to which they respond themselves and use chemotaxis for signalling. Remarkably, artificial Janus colloids that swim by catalysing reactions in a bath naturally feature chemical interactions and thereby provide a synthetic analogue to signalling micro-organisms. While, it is well known that cases where these interactions are attractive lead to clustering and phase separation, we have recently demonstrated that the purely repulsive case does not simply stabilize the uniform phase but creates a versatile new route to pattern formation in active systems.
In this talk, I will briefly review our work on chemorepulsive pattern formation and will focus the question on how generic and realistic these patterns are for Janus colloids. Our work unveils a fundamental link between autophoresis and chemotaxis leading to a massive collapse of parameter space and generic instability criteria which we confirm using particle based simulations.