Water Collection Performance of Additively Manufactured TPMS Condensation Structures in Peltier-Driven Atmospheric Water Generation: Effects of Geometry and Surface Treatment

The performance of Peltier-driven atmospheric water generation (AWG) systems depends strongly on the surface geometry and wetting behavior of the condensation structure. Triply periodic minimal surfaces (TPMS) provide high surface area-to-volume ratio and geometric tunability, but their effectiveness as three-dimensional condensation structures requires experimental evaluation. In this study, five additively manufactured TPMS geometries, Gyroid, Diamond, Lidinoid, SplitP, and Schwarz, were evaluated in a Peltier-driven AWG setup under controlled laboratory conditions. The measured water collection response varied among the tested TPMS geometries, which showed different condensation, retention, and collection trends. Water collection was measured with and without surface treatment, while the monitored surface temperature remained below the calculated dew point during testing. Without surface treatment, total water collection ranged from approximately 0.9 to 1.4 g, whereas surface-treated specimens collected approximately 0.6 to 1.2 g. The specimens with surface treatment exhibited predominantly discrete droplets rather than the film-wise morphology observed without surface treatment, but the total water collection did not increase consistently. Gyroid and Lidinoid showed slight increases with surface treatment, while SplitP, Diamond, and Schwarz showed reductions. Water collection also did not scale directly with calculated TPMS surface area, which suggests that effective air exposure, droplet retention, drainage, and coating uniformity contributed strongly to the observed performance. These findings provide experimental insights into additively manufactured TPMS geometry and surface treatment conditions for Peltier-driven AWG.