Bioinspired core-shell and twofold hierarchical structure for self-driven ultra-high water transport

Self-driven anti-gravity water transport is of great importance to energy saving, but the water transport height still presents a major practical application challenge. Herein, inspired by the multiple structures of trees, we propose a self-driven ultra-high water transport device with a radial core-shell structure and an axial twofold hierarchical structure, achieving a significant breakthrough in the water transport height of 1070 mm (one order of magnitude higher than existing materials). This structure design fully utilizes the evaporation effect based on maximizing capillary forces and Laplace pressure difference. Experiments and theoretical calculations prove that evaporation significantly limits the positive effect of driving forces on transport height. The core-shell structure of the device decreases the evaporation rate to -0 kg center dot m 2 center dot s 1, thus reducing evaporation resistance during the water transport. Furthermore, the hierarchical structure of photothermal ability created by introducing carbon nanotubes locates the evaporation at the top of the device to achieve the conversion of resistance to driving force. The bottom-up decreasing aperture was also designed in the axial core, offering strong capillary forces and Laplace pressure difference as the driving force for water transport. The novel structural design of the device will provide new insights into the energy-free transport of fluids.