AMI seminar: Wilson Poon

Room 170.048, Adolphe Merkle Institute, Marly

Thursday, April 15th, 2010  16:00 h

Dynamics and self assembly in bacterial suspensions

Prof. Dr. Wilson Poon

School of Physics & Astronomy, The University of Edinburgh, Edinburgh, UK

Bacteria inhabit the colloidal domain - a typical dimension is between 0.2 and 2 microns. But they show novel behaviour over and above those encountered in conventional, 'passive' colloids. Bacteria grow and are self motile - they are nature's active colloids. In the first part of this talk, I will show how growing E. coli bacteria self assemble into patterns that may be susceptible to description using the physics of liquid crystals. In the second part of this talk, I will turn to motility. First I will introduce a novel, high-throughput way of characterising bacterial motility based on a method for measuring colloidal diffusivity invented in Fribourg. I will then show new results obtained using this method on how the dynamics of motile and non-motile particles interact. I will end with recent observations of the self assembly of motile bacteria into micro-rotors - assemblies of active colloids that show uni-directional (or, equivalently, rectified) rotational motion.