Leidenfrost Effect, Experimental Physics Amazing Reaction

Some of you may already know the Leidenfrost Effect, the phenomenon in which a liquid in contact with a material that is much hotter than the boiling point of the liquid, it will generate vapor layer of insulation that keeps the liquid that does not evaporate quickly.

This phenomenon is most often seen when cooking, a drop of water in a pot where the temperature well above the boiling point of water or above the point Leidenfrost, the water droplets will roll down the pot and takes longer to evaporate than in the pot temperature below the point Leidenfrost (but still above the boiling point).
This effect also explains why our hands are fine although poured liquid nitrogen. Nitrogen has a boiling point of -196 ° C, and the temperature of the human body is about 37 ° C, it is very hot for nitrogen.

Then, when the meeting of liquid nitrogen by hand, the Leidenfrost effect ensued. Liquid nitrogen will be retained by the steam itself, this causes the liquid nitrogen droplets away from the surface of the skin.
However, this will not happen forever, when we are too old pouring liquid nitrogen into our hands, the hands will freeze and cause the liquid nitrogen does not evaporate as fast as before.

So, when a drop of water touching the hot surfaces (slightly above the boiling point), drops of water quickly evaporates.
But if the water droplets dropped / touch the surface very hot (well above the boiling point), only a few of the outer layer of the droplets that evaporate, producing an effect which causes the isolation of residual droplets rolling on a hot surface.

Well, when water droplets hit the surface very hot but fine, they tend scrolling or skipping to a random direction. But researchers have found that if a very hot surface has a serrated texture, droplet only moves in one direction only.
Two students from the University of Bath, Carmen Cheng and Matthew Guy, build a maze of jagged aluminum surface is then heated above the Leidenfrost point of water.

When droplets of water were dropped on this maze, it looks as if the water droplets can traverse the halls of the complex maze itself.