Figure 1: The schematic diagram of a water droplet evaporating on a flat substrate.
From: Discrete Element Model for Suppression of Coffee-Ring Effect
(a) The side view showing that the outward capillary flow carries suspended spherical monomers (single microspheres) and non-spherical dimers (pairs of monomers) to the droplet edge during evaporation. While the contact line is pinned, the droplet height is descending due to the evaporation. (b) The top view showing the simulated particle-particle interactions as 3D hexagonal close packing of particles in the bulk solution (upper left), cluster growth at air-water interface (upper right), cluster combination at air-water interface (lower left), and cluster deformation at air-water interface (lower right).
