【#Tech24H】Physicists at the University of Amsterdam recently successfully 3D-printed an 8-centimeter-tall miniature ice Christmas tree without any external freezing equipment, relying solely on the principle of evaporative cooling. The core breakthrough of this invention is that it completely dispenses with traditional refrigeration devices or low-temperature substrates, using only a nozzle and a vacuum chamber to complete the fabrication. According to the team’s paper published on the physics preprint website arXiv, the secret weapon of this low-cost technology is “evaporative cooling”, an ancient principle that utilizes physical phase change for natural cooling.