Droplets bounce-Video.
Story:
If you have ever seen a duck in the rain or in the water for that matter, you would have noticed that the duck’s feathers seem to be dry almost immediately once it get out of the water.
The duck’s feathers have a unique property that ‘propels’ water. This means that the duck can float, and instead of its feathers soaking up all the water, becoming heavy and probably sinking, it simply repels the water.
Now, we’re not sure if the same dynamic applies to the experiment the folks at Duke University did, but it does seem very likely – at least in part.
The scientific name for a surface that is highly water repellent, is superhydrophobic.
Using the high-speed camera and microscope to capture the water droplets’ movements, they set out to se what actually happens when moisture comes into contact with a water repellent material.
It seems the very tiny water droplets jumps straight off the surface. They have found the reason this happens is because of the energy released when two of these tiny droplets collide to form a larger drop. It is interesting to see how two droplets collide, merge, and then ‘jump’.
Assistant Professor Chuan-Hua Chen says knowing how and why exactly this phenomenon occurs will aid engineers in designing more efficient systems where condensate is used in cooling systems.
“In conventional cooling systems, as in big industrial plants, condensate must be removed using external forces for continuous operation,” Chen said. “One of the main benefits of this superhydrophobic surface is that it needs no external energy – the coalescing of the droplets provides all the energy needed to remove the condensate.”
http://www.new-technology-world.com/science/droplets.htm