Architecting biomimetic tree-like evaporators from hollow microtubes for enhanced solar steam generation via confined water transport

The efficiency of interfacial solar evaporation is largely governed by the subtle interplay between water transport and heat management. Herein, we present a biomimetic hollow hybrid microtube (HHT) that masters this interplay through spatially confined water flow. While prior designs often faced challenges in balancing water supply and heat localization, the unique confined capillary flow within the HHTs' walls ensures precise water transport to the evaporation interface, effectively minimizing thermal loss. The as-designed HHT achieves an exceptional evaporation rate of 3.57 kg m^-2 h^-1 under one sun irradiation. Furthermore, we conceptualize a bionic tree-like evaporator by assembling these microtubes, which demonstrates remarkable practicality by maintaining a high water collection rate of 1.50 kg m^-2 per day even under natural cloudy conditions. This work underscores the immense potential of structural innovation over mere material composition for advancing solar desalination technologies.