When a fiber possesses both the lightweight and porous characteristics of aerogel, known as "frozen smoke," and the flexibility and weavability of traditional fibers, the boundaries of functional textiles are being redefined. This new material, called aerogel fiber, combines a nano-porous structure with a one-dimensional fiber form, demonstrating disruptive potential in areas such as thermal insulation and smart response. From aerospace-level thermal protection to mass-market warm clothing, aerogel fibers are moving from the laboratory to industrialization, propelling the textile industry into a new "technology + function" track. 
I. Material Essence: The Revolutionary Fusion of Aerogel and Fiber Properties 
The core advantage of aerogel fibers stems from their unique structural gene - a three-dimensional porous network constructed with nano-colloidal particles as the framework, with gaseous medium filling the pores. It not only inherits the intrinsic characteristics of aerogels, such as ultra-low density (down to 0.035 g/cm³), high porosity (up to 99.3%), and low thermal conductivity (0.018 W/(m·K) to 0.027 W/(m·K)), but also endows the material with good flexibility and weavability through fibration. This "combination of rigidity and flexibility" trait breaks the application limitations of traditional aerogel block forms, enabling it to be directly integrated into the spinning and weaving processes of the textile industry chain. 
Based on the chemical composition of the matrix, aerogel fibers have formed three mainstream categories, each playing a different role in functional textiles: 
Inorganic aerogel fibers: Represented by silica, graphene, and MXene, they stand out for their extreme environmental stability. Among them, MXene aerogel fibers have a conductivity as high as 10⁴ S/m and possess dual response capabilities to both electricity and light heat, providing core material support for smart temperature-controlled textiles. 
Organic aerogel fibers: Organic matrices such as aramid, polyimide, and cellulose endow the materials with superior mechanical properties and biocompatibility. Polyimide aerogel fibers can maintain stable thermal insulation in a wide temperature range from -196℃ to 300℃, while cellulose aerogel fibers are preferred for green textiles due to their degradability. 
Composite aerogel fibers: Breaking through the bottleneck of single materials through component complementarity, such as the combination of sodium alginate and reinforcing materials to improve brittleness, or the integration of aerogel and polyester carriers to enhance durability. 
II. Preparation Breakthrough: From Laboratory Process to Industrial Production 
The preparation of aerogel fibers has always evolved around the three core goals of "forming - maintaining structure - improving performance". The combination innovation of wet spinning, freeze spinning and other technologies with drying processes has become the key driving force for its industrialization. 
(1) Mainstream Preparation Technology Pathways 
Wet spinning-supercritical drying combination: This is currently the most widely applied technical route. It involves injecting the sol of the aerogel precursor into the coagulation bath for shaping, followed by supercritical CO₂ drying to retain the nano-porous structure. DUY et al. prepared transparent silica aerogel fibers using this technology, which maintained good flexibility within the range of -200°C to 600°C and had a thermal conductivity as low as 0.018 W/(m·K). 
2. Freezing spinning - freeze drying combination: It is suitable for the preparation of organic aerogel fibers. By regulating the pore structure at low temperatures, the mechanical properties of the material can be enhanced. XUET et al. used polyvinyl alcohol as a pore regulator and prepared polyimide aerogel fibers with this technology, achieving a porosity of 95.6%, which can withstand extreme temperature environments. 
3. Dynamic sol-gel spinning technology: Developed for novel two-dimensional materials such as MXene, this technology builds oriented mesoporous structures through a dynamic forming process, endowing fibers with both high electrical conductivity and flexibility, thus offering a new option for wearable electronic textiles. 
(II) Key Breakthroughs in Industrialization 
The high cost and low efficiency that once restricted the application of aerogel fibers have achieved significant breakthroughs in recent years through technological innovation. The flash synthesis technology developed by Li Jiangtao's team from the Institute of Physics and Chemistry, Chinese Academy of Sciences, has shortened the preparation time of SiC aerogel to just a few seconds, with a production rate of 16 liters per minute. The manufacturing cost has been reduced by 99% compared to traditional methods, reaching only 5 yuan per liter. In terms of performance optimization, the bionic structure design by Gao Qiang's team from Beijing Forestry University has reduced the density of cellulose aerogel to only 4.1 mg/cm³, with a thermal conductivity as low as 24 mW/(m⁻¹·K⁻¹), surpassing commercial goose down in insulation performance. The team from Inner Mongolia University of Science and Technology has also solved the durability problem. The fibers they developed have a strength loss of less than 3% after 100 washes and can fully recover after radial compression of 90%.