(387b) Dynamics of Viscous Droplets Near Micro-Textured Solid Surfaces

The interaction between droplets and solid surfaces is of great importance in industrial applications, biochemical processes, and fundamental materials research. In this work, a three-dimensional spectral boundary element method has been employed to investigate the dynamics of a viscous droplet moving under gravity influence normal and parallel to a micro-textured solid surface. The surface texture is created by protruding rectangular pillars. The droplet dynamics is investigated under the influence of the Bond number, droplet size, and the topological features of the substrate. It is found that the droplet dynamics can be modified by varying Bond number and droplet size. The dynamics is also controlled by changing the height and width of the pillars. For a droplet moving parallel to the surface, the influence of pillar projection into or out of the surface is investigated. We find that the presence of the protruding surface texture greatly affects the droplet deformation, velocity or even migration direction when compared with droplet dynamics near a flat surface.