University of Amsterdam 3D Prints Ice Structures Without Supports

Researchers at the University of Amsterdam have demonstrated a 3D printing method that builds ice structures with no support material at all. The team, led by physicists Menno Demmenie, Stefan Kooij and Daniel Bonn, published their findings in the Proceedings of the National Academy of Sciences this week.

The process uses a standard 3D printer inside a transparent vacuum chamber. A water jet thinner than a human hair extrudes room-temperature water onto a build surface. As the water evaporates under low pressure, it pulls heat away from the liquid, cooling it below freezing while it remains liquid. The moment the stream hits the already-frozen layer beneath, it solidifies instantly.

Overhangs without supports

By slowing the print speed, the researchers found they could tilt emerging pillars as far as 14 degrees from horizontal and still keep them standing. That angle is steep enough to print arbitrary profiles, including a human face, without any support material underneath. Ordinary FDM and resin printers need supports for any overhang beyond a few degrees.

The printed ice is pure. There are no added chemicals or binding agents. When the vacuum pump is turned off, everything melts back into clean water. That reversibility makes the method attractive for microfluidics, where ice channels can be created and then thawed away, and for tissue engineering, where ice scaffolds can serve as temporary templates.

Mars applications

The authors note that the same technique could work on Mars, where low atmospheric pressure and cold temperatures make evaporative cooling even more efficient. In principle, a future Mars mission could use local water ice and a vacuum chamber to print habitats or tools without bringing along supporting materials.

The December 2025 ice Christmas tree that went viral was an early proof of concept. This new paper moves the method from a novelty into a documented, repeatable process with measurable mechanical properties and practical use cases.