Abstract:

Significance Global climate change has led to more frequent and intense extreme heat waves and cold waves. Personal temperature-constant thermal management fabrics can upgrade conventional passive protective fabrics into active and self-adaptive "second skin", enabling the human body to remain comfortable at different external temperatures. Ordinary personal thermal management fabrics are often designed with specific functions for particular environments. However, in actual wear, human activities and environmental temperatures are constantly fluctuating, such as when entering an air-conditioned room from outdoors or when experiencing a sudden increase in body heat during exercise. In such cases, unidirectional functions may fail or even be counterproductive. Therefore, how to achieve both heating and cooling functions on the same fabric and respond dynamically to the external environment is a core issue in the field of personal thermal management. Personal thermal management fabrics that can switch between heating and cooling functions and maintain a constant temperature (hereinafter referred to as constant-temperature thermal management fabrics) have a core value in dynamically maintaining the relative stability of the human body temperature, rather than merely enhancing heat dissipation or insulation in a single direction.

Progress Temperature-constant thermal management fabrics achieve intelligent regulation of the human thermal environment by dynamically adjusting the physical or chemical properties of the fabric. The switching between cooling and heating functions typically relies on active or passive changes in the fabric's structure or performance. Phase change temperature-constant thermal management fabrics are evolving from a single "passive energy storage" mode towards the directions of multi-functional coupling and high-efficiency encapsulation technologies. Radiative temperature-constant thermal management fabrics have the potential to be integrated with functions such as electromagnetic shielding, sensing and thermoelectric conversion, and multi-functional integration has become a new development trend for radiative thermal management fabrics. In recent years, the combination of directional sweat transport with dynamic heating and cooling has emerged as a new research hotspot in the development of moisture-regulating temperature-constant thermal management fabrics. Multi-modal temperature-constant thermal management fabrics have broken through the single regulation function of heat conduction or thermal radiation, which integrate flexible sensing arrays and utilize brain-like computing to perceive microclimate changes on the skin surface in real time, thus achieving nonlinear and regionally differentiated precise temperature control. Future research on temperature-constant thermal management fabrics needs to seek breakthroughs through interdisciplinary collaboration in areas such as intelligent responsive materials, scalable preparation processes, and system integration.

Conclusion and Prospect Temperature-constant thermal management fabrics can dynamically maintain the stability of the micro-environment temperature of the human body and significantly enhance the thermal comfort and health safety guarantee of the wearer in a variable environment. The focus is on developing a new generation of intelligent materials that can autonomously respond to the external environment or human body conditions (such as temperature, humidity, sweat, and bioelectrical signals), so as to achieve an adaptive close-loop temperature control system without human intervention. Deep integration of thermal management functions with health monitoring, energy harvesting, information display and other technologies should be promoted in order to build a multi-functional intelligent textile platform with self-powering capabilities. The future research should focus on resolving the core contradiction between comfort, durability and large-scale production, and the solutions should be scaled up from the laboratory to industrialization through low-cost processes and green materials, ultimately achieving large-scale application in fields such as medical health, special protection and daily wear.

Key words: temperature-constant thermal management fabric, personal thermal management, self-adaptation, intelligent temperature regulation, phase change material, thermal radiation, functional textiles