Coalescence-Induced Self-Propulsion of Droplets on Superomniphobic Surfaces.

We utilized superomniphobic surfaces to systematically investigate the different regimes of coalescence-induced self-propulsion of liquid droplets with a wide range of droplet radii, viscosities, and surface tensions. Our results indicate that the nondimensional jumping velocity V is nearly constant (V ≈ 0.2) in the inertial-capillary regime and decreases in the visco-capillary regime as the Ohnesorge number Oh increases, in agreement with prior work.