The Leidenfrost effect is a phenomenon. It makes water droplets bounce, dance, and move in speed in random directions on any hot vessel.
There are so many interesting phenomena which goes ignored in your daily life, as you never give in much time to observe. But if you see closely while working, you would be able to discover many such interesting events.
What was the observation?
The observation was closely noted for the first time by a Russian, who uploaded his observation as videos on Youtube to bring this to notice of other enthusiasts. Here he showed how hydrogen drops when thrown in a very hot frying pan, started to bounce and jump and speed up.
The same thing happens with water droplets too. When you sprinkle little water on a hot vessel or pan, then you would see the droplets almost come to life and springing all over the hot surface in any random direction. This may seem strange to you, but has strong reasons and laws of physics behind the behavior.
When hydrogel drops are thrown instead of water drops, the same thing happens but more vigorously. The hydrogel is similar to water where most of the water content is bonded or held together using a raisin or plastic polymer to form a water drop. Hydrogen droplets make a strong noise which sounds shrill and bounces too fast and high, almost 20 times their radius.
The Leidenfrost effect
This effect has been named the Leidenfrost effect after studies by scientists of the Leiden University, Netherlands. The explanation given for this strange behavior of water drops on touching a hot surface is quite interesting. It happens due to the energy released during the super fast vaporization of water on touching the very hot surface.
When the droplets touch the hot surface, instantly some part of the drop gets vaporized. As steam is released, the steam pushes the drop up or sideways in instant kick of energy.
The drop bends in shape, and instantly comes back or springs back to shape to touch the hot surface again while getting vaporized partly again. More vapor means more energy, and the gradually diminishing size of the drops due to vaporization with every touch of the hot pan helps make them bounce higher due to a higher impact of the steam energy.
It’s like creating a steam machine in a frying pan, where water or hydrogel droplets are powered to rock by the steam pressure.