Jamming of soft particles in porous media, phase transition imposed by a template

Flow and transport of soft particles, such as red blood cells or emulsions, through porous membranes are ubiquitous in medical and industrial applications. We experimentally investigate the transport of soft particles and emulsions in a two-dimensional porous medium using optical microscopy and bulk transport measurements. Our findings show that high concentrations of soft particles can percolate through high-permeability media, provided that the local porosity and average pore size permit the passage of individual particles. However, increasing the heterogeneity of the pore structure leads to intermittent transport and the formation of jammed particle regions. As particle concentration increases, the peak of the pair correlation function decreases due to particle deformability. Additionally, we observe significant changes in giant number fluctuations, resembling a transition from a crystalline to a disordered phase, as the concentration of injected soft particles varies.