Knitting-stitching bifacial metafabrics with switchable thermal and moisture transmissibility for multimodal dynamic personal thermoregulation.

Abstract

Smart textiles with thermal and moisture management functionalities are highly desirable for enhancing human comfort and reducing weather-related health issues. However, achieving high-performance thermoregulatory fabrics that simultaneously exhibit reversible cooling and heating functions, and effective sweat management through industrial fabrication, remains challenging due to the lack of compatible textile technologies capable of manipulating hierarchical structures. Herein, a robust thermal and moisture-managing metafabric (TMM fabric) with a stitching-interlaced-knit structure is developed using industrialized machine knit technology. Unlike layered fabrics, this knitted structure endows the TMM fabric with different appearances on its two opposite surfaces for reversible photon management, while integrating these surfaces into an all-in-one construction using interlacing yarns. The interlacing yarns also serve as pathways for heat and moisture transmission, enhancing thermal conduction and water transportation. A coupling agent-assisted zinc oxide nanoprocessing is further applied to the cooling surface of the TMM fabric to improve solar reflectivity. The bifacial TMM fabric demonstrates on-demand radiative/evaporation cooling and photo-thermal heating capacities by simply flipping the fabric, achieving an effective temperature regulation of over 17 °C. Furthermore, the TMM fabric shows desirable electro-thermal performance, enabling it to protect the human body from harsh low-temperature conditions of -18 °C. Moreover, the TMM fabric demonstrates good breathability and robust mechanical properties. This facile structural design as a paradigm provides a new insight for producing scalable, robust and efficient personal thermoregulation textiles adaptive to superwide temperature changes using well-engineered textile structures.