Hi, this is Wayne again with a topic “Crystal critters”.
[, MUSIC PLAYING ] NARRATOR, A team of MIT researchers, have found that when salty water evaporates from a heated super hydrophobic surface the crystal structures that form ultimately self-eject from the surface.. This self-ejection occurs via the growth of crystalline columns or legs. During the end phase of evaporation. As fluid moves through the legs of these structures towards the surface, continuous crystallization pushes the legs upwards.
Until evaporation of water is complete., The resulting structure is a crystal globe balanced on legs with limited or no adhesion to the surface.. Because of this minimal contact, the structures are easily removed and will occasionally roll away on their own.. The researchers have dubbed these structures crystal critters due to the resemblance of biological forms.
We are familiar with such as a crab or an elephant, and even some nonbiological structures like a Droid from the movie Star Wars., Because the critters grow due to evaporation at the surface. The growth rate therefore increases with temperature.. The researchers found that they can take advantage of the temperate dependent growth by applying a temperature gradient to the surface, which would induce rolling and therefore make it even easier to remove the structures once evaporation is complete.. Otherwise, over time, an accumulation of these impurities reduce heat transfer, performance block pipes and generally cause material, corrosion and deterioration..
This phenomenon could make it possible to use brackish or salty water without any expensive pretreatment, rather than relying on fresh water sources for cooling systems in power plants. .