{"id":3255,"date":"2026-01-28T15:24:01","date_gmt":"2026-01-28T14:24:01","guid":{"rendered":"https:\/\/iop.fnwi.uva.nl\/scm\/?p=3255"},"modified":"2026-01-28T15:35:29","modified_gmt":"2026-01-28T14:35:29","slug":"a-3d-printed-christmas-tree-made-entirely-of-ice","status":"publish","type":"post","link":"https:\/\/iop.fnwi.uva.nl\/scm\/index.php\/2026\/01\/28\/a-3d-printed-christmas-tree-made-entirely-of-ice\/","title":{"rendered":"A 3D-printed Christmas tree made entirely of ice"},"content":{"rendered":"\n

A team of physicists from the University of Amsterdam\u2019s Institute of Physics has 3D-printed a Christmas tree made entirely of ice. Researchers Menno Demmenie, Stefan Kooij and Daniel Bonn used no freezing technology or refrigeration equipment\u2014just water and a vacuum. In time-lapse videos, you can see how the Christmas tree is printed and how it melts again when the vacuum pump is turned off.<\/p>\n\n\n\n

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The secret of the tree lies in so-called evaporative cooling. This is the same principle mammals use to regulate their body temperature.<\/p>\n\n\n\n

In a low-pressure vacuum chamber, water evaporates rapidly at room temperature. As each water molecule evaporates, it takes with it a small amount of heat, causing the remaining water to become increasingly colder, eventually cooling to below zero degrees Celsius. At that point the water is still liquid, but supercooled. As soon as the ultra-thin stream (about as thin as a human hair: 16 micrometres) hits the already formed layer of ice, it freezes instantly.<\/p>\n<\/div>\n<\/div>\n\n\n\n

A complex ice-ornament<\/h2>\n\n\n\n

Layer by layer, a complex ice sculpture is created \u2013 complete with branches and details. No support material is needed, and there’s no waste. This 8-centimetre-tall tree was finished in 26 minutes<\/p>\n\n\n\n

https:\/\/www.youtube.com\/watch?v=1Luwz1dzw-I<\/a><\/p>\n\n\n\n

And when you turn off the vacuum pump, everything melts neatly back to clean water:

https:\/\/www.youtube.com\/watch?v=UjoDp_WmGF4&t=1s<\/a><\/p>\n\n\n\n

Scientific value<\/h2>\n\n\n\n

The same process also works for other shapes: cones, pillars, even leaning structures without support. This method isn’t just fun items such as frozen ornaments during the Christmas season \u2013 its scientific value lies in its visibility. You can see phase transitions, heat transfer and the role of pressure \u2013 all in real time through the transparent vacuum chamber.<\/p>\n\n\n\n

Practical applications<\/h2>\n\n\n\n

Moreover, the researchers say there are practical applications: the technique opens doors for biology (pure ice structures as scaffolding for tissue) and microfluidics (forming intricate channels by melting away the ice). And on Mars? It’s cold there, and the atmosphere is thin \u2013 perfect conditions for using the same technique to build structures with local water.<\/p>\n\n\n\n