Droplet Motion on Superhydrophobic Surfaces

In this talk, molecular dynamics simulations are used to investigate the roles of droplet size and surface geometry on the equilibrium velocity of droplets moving down superhydrophobic surfaces. An extension of prior theoretical descriptions, accounting for interfacial slip, is used to interpret these results. This approach yields three limiting cases for the drop’s steady-state velocity, where energy losses are dominated by viscous dissipation, surface friction or contact line friction respectively.
We find that for droplets on ideal textured high-slip surfaces, contact line dissipation dominates droplet motion, with drop velocity increasing with radius. At droplet radii larger than the capillary length, we retrieve the usual viscosity-dominated motion.