Collective Dynamics of Dipolar and Multipolar Colloids: From Passive to Active Systems

In this talk I will present recent research on the collective dynamical behavior of colloids with dipolar or multipolar interactions. Starting from “passive” dipolar particles exhibiting network formation and various types of cluster aggregation, we will then move towards systems composed of dipolar “microswimmers” with unidirectional propulsion. These systems display a transition towards a laned state reminiscent of lane formation in driven systems with isotropic repulsive interactions. We interpret our findings by a phase separation process and force balance arguments. Finally, we discuss first results on the collective behavior of dipolar particles with random self-propulsion.