Clustering and Pattern Formation with Chemically Interacting Microswimmers
- Event time: 1:00pm
- Event date: 22nd February 2016
- Speaker: Benno Liebchen (Formerly School of Physics & Astronomy, University of Edinburgh)
- Location: Lecture Theatre C, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
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. This can, in the case of chemoattraction where particles migrate up chemical gradients, induce a clustering-instability of the uniform phase and lead to structure formation. This instability currently attracts renewed attention in artificial Janus colloids that swim by catalysing reactions in a chemical bath and show a similar signalling behaviour as micro-organisms.
In this talk, I will demonstrate that also chemorepulsive signalling (where particles migrate away from high chemical density) allows for an instability of the uniform phase. This instability creates a route to the formation of structures such as travelling waves and clusters of self-limiting size which can either be stationary or may oscillate periodically. Finally, I will briefly talk about our latest work on chemotaxis in circularly swimming particles such as bacteria close to walls or synthetic 'L-shaped' colloidal microswimmers.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..