Activity-induced interactions and collective response in active colloidal suspensions

Active suspensions can displace in a liquid medium in which they are suspended as a result of nonequilibrium processes, such as chemical reactions, or inhomogeneous thermal heating. These are intrinsically out of equilibrium systems, which makes them very versatile, with a natural tendency to self-assemble. Due to their small size, these out of equilibrium dynamical states generates flows that induce long range hydrodynamic interactions. These interactions have profound effects in the transport and assembly of colloidal suspensions.

I will analyze the role that hydrodynamics play in the rectification mechanism that leads to their motion, as well as the possibility that hydrodynamic instabilities lead to novel estates of self-propulsion. I will discuss the impact that these mechanisms have in the emergence of patterns and different type of morhological structures in model active suspensions. I will combine theoretical simple models and computer simulations to gain insight in the role of hydrodynamics in these out of equilibrium system.