3D Printed Liquid Crystal Polymer Thermosiphon for Heat Transfer under Vacuum

A novel approach is presented to 3D print vacuum–tight polymer components using liquid crystal polymers (LCPs). Vacuum–tight are essential for gas storage and passive heat transfer, but traditional printing methods often suffer from poor interfaces between layers high free volume, compromising vacuum integrity. By harnessing the unique properties of LCPs, including low volume melt viscosity, highly ordered domains achieved through nematic alignment chains. Critical gas–barrier demonstrated, even in thin, single–print line–walled samples ranging 0.8 1.6 mm. 200 mm evacuated thermosiphon successfully printed, which exhibits a thermal resistance up 2.18 K/W an effective conductivity 28 W/mK at 60 °C. These values represent significant increase compared base LCP material. Furthermore, geometric freedom, enabled by fabrication complex–shaped thermosiphons, showcased. The authors study highlights potential LCPs as high–performance materials with intricate geometries, opening new avenues functional design. An application integrating printed thermosiphons selective transfer building envelopes presented, contributing greenhouse emissions mitigation construction sector.