Special Chemical Engineering Seminar

While the collective behaviour of passive colloidal particles is by now well-studied, we are just beginning to understand the behaviour of self-propelled "active" particles.  Bacteria show interesting swarming and this can be mimicked by artificial colloidal microswimmers.  This talk will address a number of phenomena in active matter ranging from the most disordered state of matter (turbulence) to the most ordered state of matter (crystal).  In detail, we explore the dynamics of strongly interacting active colloidal particles by computer simulations, theory and experiment.  In the two-dimensional bulk, anomalous turbulence ("swirling") emerges in agreement with recent experimental data on bacterial motion.  The bacterial turbulence can be exploited to power the motion of micro-carriers.  The statistics of Brownian chiral circle swimmers is discussed both in the bulk and in an external gravitational field.  Finally we study the crystallization transition and phase separation for self-propelled particles.  In particular, scaling laws for kinetic clustering of active particles are extracted.