Metafabrics for Thermoregulation and Energy-Harvesting Applications

Metafabrics are textiles with engineered constituent elements, possessing peculiar properties, which cannot be achieved with conventional fabrics. Fabric structures are formed of fibers bundled up and twisted into yarns. Yarns are then intertwined or bond closely together to shape the fabric structure. Engineering the textiles can be performed by utilizing novel materials for constitutive fibers and also manipulating the size and structure of fibers and yarns. In this paper, we employ a powerful and realistic model to design and investigate metafabrics for unique applications in personal thermal cooling, thermal insulation, and thermoregualation by means of engineering fabric building blocks. We provide physical insights into the behavior of the so-called infrared-transparent visible-opaque fabrics (ITVOFs), study the effect of using metallic-coated fibers on the thermal insulation functionality of a breathable textile, and also propose an alternative form for phase-change fabrics (PCFs) consisting of core–shell fibers with phase-change material (PCM) cores. Also, we develop a robust design principle to transform fabrics into fully functional devices, guiding, and manipulating thermal radiation through graded yarns with core–shell fibers. In particular, a focusing metafabric is designed to concentrate the thermal radiation into localized high energy spots. We integrate this focusing device into a multilayer technical platform to harvest the thermal energy from human body through effectively coupling the thermal radiation into a layer of IR-detector material. A considerable enhancement ratio of 7.46 is achieved in the current density generation through the metafabric.