Density Dependent Cohesion Leads to Controlled Phase Separation in Brownian Suspensions

Mechanical interactions between biological cells may be mediated by secreted products, making them dependent on the local particle density. Here, we explore the generic physics of density-dependent attractive interactions. We show using Brownian dynamics simulations that density-dependent interactions can produce interesting phase separation behaviour including control of aggregate size during a spinodal decomposition-like separation process. We show that these results are generic using continuum modelling of the appropriate Cahn-Hilliard equation. Our study suggests that density-dependent interactions can provide a generic mechanism for control of aggregate size during phase separation.