Modeling large diffusio-phoretic suspensions*

Phoretic particles swim by catalysing chemical reactions thus generating concentration gradients and phoretic slip flows along their surfaces. Their collective dynamics can lead to the emergence of intriguing collective dynamics and modifications in the effective properties of the suspension (e.g. viscosity and diffusivity). The numerical modeling of these reactive suspensions implies solving sequentially the Laplace and Stokes equations around many particles with prescribed surface boundary conditions, with a computational cost rapidly increasing for large numbers of particles.

We present here a novel framework for the simulation of this coupled problem. This Diffusio-phoretic Force Coupling Method is more accurate than far-field approaches, but significantly less expensive than exact methods, and is implemented in a parallelized and efficient solver to analyze the collective motion and microstructure of semi-dilute suspensions.