Direct-ink-write 3D-printed surface energy gradient monolith enabling adaptive cooling regulation

The practical implementation of radiative cooling is hindered by inadequate daytime cooling capacity and undesirable nighttime overcooling. Although phase-change thermal regulation can mitigate this spatiotemporal mismatch, the customized preparation and integrated functionality of such dual-temperature regulation systems remain a challenge. Herein, a surface energy gradient monolith with selectively enriched phase-change liquid domains is fabricated via printhead-switchable direct-ink-write 3D printing. This architected monolith features a programmable macroscopic geometry and a pronounced surface energy gradient across its thickness: the high-surface-energy bottom layer enables efficient phase-change liquid loading and rapid thermal response, while the low-surface-energy porous top layer strongly reflects solar radiation and suppresses parasitic environmental heat gain. By synergistically merging radiative cooling with phase-change temperature regulation, the monolith achieves superior adaptive cooling performance, lowering temperatures by 2.8 °C vs. the porous top layer alone in hot daytime and raising temperatures by 4.3 °C via latent heat release to mitigate radiative supercooling at nighttime. ... mehrThis study might establish a foundation for the precise 3D printing of programmable gradient-architected materials for on-demand cooling management.