A Janus textile mimics leaf stoma for dynamic thermal regulation through a shape memory coating

The development of smart textiles with thermal/moisture regulation is crucial for outdoor activities and healthcare applications. However, incorporating dynamic adaptive thermal management into conventional fabrics to provide consistent comfort remains a significant challenge. Inspired by the ingenious stomata of plant leaves, a novel Janus-type cotton fabric is fabricated by covalently linking shape memory polymer (SMP) on the surfaces of cotton fibers via the combination of the "grafting from" strategy and the "mist polymerization" methodology. This unique coating induces yarns to dynamically twist in response to temperature, switching the pore apertures in the fabric and allowing for adaptive adjustment of both heat dissipation capability and moisture permeability. The resulting fabrics provide effective thermal insulation at low temperatures, while demonstrating an enhanced cooling effect at high temperatures. Meanwhile, the asymmetrical distribution of SMP across the fabric enables unidirectional water transport, improving sweat removal and cooling. Additionally, the excellent biocompatibility and fabric flexibility allow for comfortable garment fabrication. This work provides novel insights into the field of self-adaptive thermal regulation, demonstrating promising potential for smart textile applications.