Fig. 2: Liquid diode with directional water transport for dehumidification and self-cooling.

a Water transport in the channels of fibers with different hydrophilicity. b Breakthrough pressure of hydrophilic and hydrophobic side in the gradient fabric with different TiO₂ contents in the spraying process. c Element distribution of pristine, hydrophilic and hydrophobic nylon by X-ray photoelectron spectroscopy analysis after 3.58 wt.% TiO₂ solution was sprayed on the fabrics. d Water transport rate along the thickness with different applied water height. The water transport from “O” side and “I” is positive and negative, respectively. e, f Water transport through gradient fabric by dropping dyed water on the hydrophilic side e and hydrophobic side f. g Water evaporation on the nylon fabric and gradient nylon fabric by dropping water on the hydrophobic side. h Wetting rates in the different directions of water transport in the gradient fabric. i Photos of dehumidification by gradient fabric on the sweating arm. j Optical and infrared image of self-cooling by gradient fabric on a sweating arm. Error bars represent the standard deviation. Source data are provided as a Source Data file.