1+1D Surface Growth of Particles: From Spheres to Rod-Shaped Bacteria and Red Blood Cells

We investigate the dynamics of surface growth resulting from falling spherical granular particles in air or liquid environments and the aggregation of bacteria and red blood cells at the edges/centers of drying drops. Surface roughness is quantified from images, and growth and roughness exponents are measured. Additionally, we perform numerical simulations using the discrete element method, considering the interactions between grains. Unlike conventional simulation models, this method obtains the dynamics of individual particles throughout the process, considering different forces acting on the particles. Finally, the simulation results are compared with experimental data, showing a very good agreement. In all cases, we find growth and roughness exponents that are not consistent with standard scaling models.