Investigation of the flight of liquid microdroplets over the contact line in a horizontal liquid film heated from below

When a liquid layer is heated from the substrate, a structured array of levitating microdroplets can be formed near to the surface of the liquid. When a dry spot is formed on the substrate through the liquid layer, the droplets can move under the action of gravity towards the dry spot so that propagation of microdroplets from a wetted to a dry substrate area is accompanied by a substantial change in the droplet levitation height above the contact line. It was found that with an increase in the diameter of a microdroplet, the maximum height of the trajectory, and the flight distance of the drop, decrease.