Hierarchical Weaving Metafabric for Unidirectional Water Transportation and Evaporative Cooling

Abstract

Smart apparel with unidirectional sweat transportation functionality is highly desirable for wearing comfort. However, simultaneously achieving fast unidirectional water transport, mechanical robustness, human body comfortability, and industrialized fabrication is challenging because of the difficulty in fiber-yarn-fabric multiscale textile structure manipulation. Here, for the first time, a unidirectional water-transportation metafabric (UWTM) with hierarchical weft-double-weave structure is developed using industrial-producible weaving technology. The UWTM not only shows a fast unidirectional sweat transportation property, but also a robust mechanical property, air permeability, tailorability, and human body comfortability. The unidirectional water transportation is realized by a well-engineered wettability gradient along fabric thickness direction by two-set weft yarns and one-set warp yarn. The UWTM shows a strong one-way transport capacity of 984%, with a short water droplet transportation time of 4 s. In addition, the unidirectional water transportation leads to an evaporative cooling effect to the human body, resulting in a 1.6 °C cooling compared with the most used cotton fabrics, exhibiting excellent wet-heat transfer responsiveness, and ensuring a comfortable microclimate between human skin and the environment. The facile and scalable method presented here paves a way for the design of fluorine-free, robust, comfortable, and wearable unidirectional water transport fabrics.