U.S. patent application 20190191589 (applicant Google LLC, Mountain View, Calif.):
"This document describes techniques for implementing phase-change cooling in a three-dimensional structure. A three-dimensional structure having three-dimensional curvatures is fabricated to include a phase-change chamber with a fluid in a saturated thermodynamic state. As part of fabrication, specific mechanisms may be included that create a thermo-mechanical network that improves thermal performance of the phase-change chamber and also provides structural integrity to the three-dimensional structure. ... Structures housing heat-producing components, such as a virtual reality headset, a personal assistant/smart speaker, a smartphone, or gaming controller, are often shaped with complex, three-dimensional curvatures. As part of manufacturing such a structure and using specific techniques, phase-change mechanisms using a phase-change material (PCM) may be integrated as part of the structure, improving thermal control over the electronic system that might otherwise rely on convection or conduction based mechanisms."