Multiscale thermodynamic engineering for next-generation smart textiles

Maintaining human thermal comfort relies heavily on energy-intensive space heating and cooling, significantly exacerbating global energy consumption and greenhouse gas emissions. Although functional clothing has made rapid progress, there is a lack of systematic understanding on how to integrate the multiscale structural engineering from the intrinsic material properties to the macroscopic fabric topology in a coordinated manner to break through the thermodynamic limitations of traditional textiles. This review provides a comprehensive overview of multiscale thermal management textiles for localized personal microclimates, extreme occupational protection, and wearable electronics, aiming to maximize personal energy savings and specifically address the pronounced research deficit concerning the scalable, durable, and sustainable deployment of these smart fabrics. The strategies of meticulous structural control across multiple dimensions, including 1D intrinsic fiber engineering, mesoscopic yarn assemblies, and 2D/3D macroscopic Janus or biomimetic fabric topologies, are systematically highlighted to dynamically modulate heat conduction, convection, and multi-band radiation. This review offers a critical framework, design principles, and a roadmap for developing next-generation intelligent textiles aimed at getting rid of reliance on the heating, ventilation, and air conditioning (HVAC) systems in building, ultimately accelerating the transition toward global carbon neutrality and sustainable personal thermal management (PTM).