Physicists at the University of Amsterdam created a truly cool little Christmas decoration: a mini 3D-printed Christmas tree, a simple 8 centimeters high, made from ice, with no refrigeration devices or other freezing innovation, and at very little expense. The trick is evaporative cooling, according to a preprint published to the physics arXiv.

Evaporative cooling is a widely known phenomenon; mammals utilize it to manage body temperature level. You can see it in your early morning cup of hot coffee: the hotter atoms increase to the top of the magnetic trap and “leap out” as steam. It likewise contributes (together with shock wave characteristics and different other elements) in the development of “white wine tears.” It’s an essential action in developing Bose-Einstein condensates.

And evaporative cooling is likewise the primary perpetrator behind the notorious “stall” that so regularly afflicts ambitious BBQ pit masters excited to make an effective pork butt. The meat sweats as it cooks, launching the wetness within, which wetness vaporizes and cools the meat, efficiently counteracting the heat from the BBQ. That’s why a growing variety of competitive pit masters cover their meat in tinfoil after the very first couple of hours (normally when the internal temperature level strikes 170° F).

Ice-printing approaches typically depend on cryogenics or on cooled substrates. Per the authors, this is the very first time evaporative cooling concepts have actually been used to 3D printing. The technique was to house the 3D printing inside a vacuum chamber utilizing a jet nozzle as the printing head– something they found serendipitously when they were attempting to eliminate air drag by spraying water in a vacuum chamber. “The printer’s movement control guides the water jet layer-by-layer, constructing geometry as needed,” the authors composed in a post for Nature, including: