EPL Focus Issue on Statistical Physics of Self-Propelled Colloids Editorial

Editorial Micron-sized particles equipped with their own motorization have been a topic of intense recent research in physics. These mesoscopic active entities can harness and harvest energy from the environment and are therefore important as carriers of drugs and cargos. Their motion is governed by the laws of nonequilibrium physics. Well-characterized self-propelled colloids are ideal model systems to study the underlying novel concepts of nonequilibrium statistical physics in a quantitative and systematic way. While different self-propulsion mechanisms for a single colloidal particle in a surrounding bulk fluid are by now well understood, new research has considered such particles in a heterogenous and complex environment and also focussed on many-body systems. A wealth of new nonequilibrium structures and patterns has been discovered which are much richer than those of their equilibrium counterparts. Moreover, an important step is to equip the particles with more “intelligence” such that they can sense stimuli, learn to react to those and perform simple tasks in an optimized way. Complementary work involving laboratory experiments of well-controlled model systems, computer simulations, and a broad spectrum of theoretical methods from statistical physics have provided important new insights in this interdisciplinary research area. This Focus Issue of EPL includes one perspective article [1] and 17 research letters [2–18] all centered around statistical physics of self-propelled colloids.