Nano- and Micro-Polymer Fibers for Smart Actuation: Fabrication Methods and Applications-A Review

Polymeric fibers represent a vital class of functional materials due to their versatile properties, such as wide availability, low cost, recyclability, biodegradability, and excellent mechanical and chemical stability. Polymer fibers can be fabricated at both micro- and nanoscale dimensions using a variety of processing techniques. This review provides a comprehensive overview of the principal methods employed for polymer fiber preparation, including electrospinning, melt and solution blowing, dry and wet spinning, template synthesis, phase separation, and self-assembly. The technical principles, as well as the advantages and limitations, of each technique are systematically discussed. The review also explores polymeric fibers as smart materials for actuation applications. Particular focus is given to stimulus-responsive fiber systems such as shape memory fibers, hydrogel fibers, liquid crystal fibers, and electroactive polymers. Overall, this review establishes a coherent framework linking polymer fiber fabrication strategies with structure-property-function relationships, offering practical guidance for material selection and accelerating the development of next-generation smart polymer fibers for advanced actuation and multifunctional applications.