Droplet behaviors and growth regimes on superhydrophobic surfaces

This paper fabricates a micro-nano structured superhydrophobic surface with condensation experiments performed on the horizontal superhydrophobic surface under natural convection conditions in humid air. The results show that the droplet behaviors can be classified into three types including droplet coalescence, droplet jumping and droplet sweeping, where both the droplet jumping and the droplet sweeping are self-propelled motions triggered by the droplet coalescence. Compared with the droplet jumping, droplet sweeping is a different behavior that the objective droplet sweeps past the surface merging all droplets in its path and finally stops at some place leaving a long and narrow track with a large droplet staying at the end. Statistical approach is also used to obtain the droplet size distributions, the average droplet diameters and the surface coverage to investigate the growth regimes of the condensate droplets.