Burning drops bounce. Credit: Zulu et al. , 2025
The drops that wear on the surfaces are a daily phenomenon, such as rain drops that bounce from lotus leaves or water drops flow into a hot frying pan, slip and slip around – with the effect of Leidenfrost. There is also a reverse effect of Leidenfrost, described for the first time in 1969, which includes a hot object like drops lifted on a cold surface. Understanding the mechanisms behind these phenomena is extremely important for a wide range of practical applications, such as self -cleaning, anti -coordination, anti -pressure, charge printing, or logic -based logic systems.
The drops are usually bounced only if the surface is roasted or somehow engineering to reduce isolation. Physicists from Hong Kong University discovered how this high behavior of hot oil drops is achieved from almost any surface, according to New paper Posted in Newton’s magazine.
As we had previously informed, in 1756, a German world was named Johan Gotlop Leidenfost I mentioned His note From the extraordinary phenomenon. He pointed out that the water usually fired on a very hot frying pan and evaporates very quickly. But if the pan’s temperature is much higher than the boiling point in the water, the “luminous declines that resemble Quicksilver” will form and ski across the surface. It is called “Leidenfrost effect “ In his honor.
During the 250 years after that, physicists have reached an applicable explanation for the reason for this. If the surface is not less than 400 ° F (much higher than the boiling point of water), then the water vapor or steam pillows, formed under it, while keeping it useful. The Leidenfrost effect also works with other fluids, including oils and alcohol, but the temperature in which it appears will be different.
The phenomenon continues to dazzle physicists. For example, in 2018, French physicists discovered The drops are not only installed on a steam pillow; As long as it is not too big, it also pushes itself. In 2019, an international team of scientists Finally select the source From the sound of the associated with Lidenfost mentioned. Scientists have found that this depends on the size of the drops; They are the largest drops that explode with the Telltale rift. You can even achieve the Leidenfrost effect with ice, as physicists in Virginia Tech Prejudiced In 2022.