Energy and Matter Supply for Active Droplets

Abstract

AbstractChemically active droplets provide simple models for cell‐like systems that can grow and divide. Such active droplet systems are driven away from thermodynamic equilibrium and turn over chemically, which corresponds to a simple metabolism. Two scenarios of nonequilibrium driving are considered. First, droplets are driven via the system boundaries by external reservoirs that supply nutrient and remove waste (boundary‐driven). Second, droplets are driven by a chemical energy provided by a fuel in the bulk (bulk‐driven). For both scenarios, the conservation of energy and matter as well as the balance of entropy are discussed. Conserved and nonconserved fields are used to analyse the nonequilibrium steady states of active droplets. Using an effective droplet model, droplet stability and instabilities leading to droplet division are explored. This work reveals that droplet division occurs quite generally in active droplet systems. The results suggest that life‐like processes such as metabolism and division can emerge in simple nonequilibrium systems that combine the physics of phase separation and chemical reactions.