  Biomolecular condensates play a central role in the spatial organization of
living matter. Their formation is now well understood as a form of
liquid-liquid phase separation that occurs very far from equilibrium. For
instance, they can be modeled as active droplets, where the combination of
molecular interactions and chemical reactions result in microphase separation.
However, so far, models of chemically active droplets are spatially continuous
and deterministic. Therefore, the relationship between the microscopic
parameters of the models and some crucial properties of active droplets (such
as their polydispersity, their shape anisotropy, or their typical lifetime) is
yet to be established. In this work, we address this question computationally,
using Brownian dynamics simulations of chemically active droplets: the building
blocks are represented explicitly as particles that interact with attractive or
repulsive interactions, depending on whether they are in a droplet-forming
state or not. Thanks to this microscopic and stochastic view of the problem, we
reveal how driving the system away from equilibrium in a controlled way
determines the fluctuations and dynamics of active emulsions.
