Multifunctional Magnetic Soft Fibers: A Platform for Wearable, Biomedical, and Soft Robotic Systems

Magnetic soft fibers (MSFs) have emerged as a promising class of stimuli-responsive materials that combine magnetic functionality, mechanical compliance, programmable magnetization, and multifunctional performance within fiber-based architectures. Their ability to enable wireless actuation, adaptive deformation, sensing, and electrical energy generation has attracted growing interest in wearable electronics, biomedical devices, and soft robotic systems. This review aims to provide a comprehensive overview of the fundamental principles, material systems, fabrication methods, magnetization strategies, and emerging applications of MSFs. The review highlights that recent advances in material design, scalable fabrication technologies, and programmable magnetization have enabled MSFs to evolve from simple magnetic composites into multifunctional platforms capable of actuation, sensing, and energy harvesting within a single fiber system. Furthermore, the integration of electrical, optical, and fluidic functionalities has expanded their potential in wearable monitoring, minimally invasive biomedical devices, adaptive soft actuators, and remotely actuated robotic systems. Key challenges associated with material optimization, scalable manufacturing, and long-term reliability are also identified, along with emerging opportunities in intelligent design and adaptive control. By consolidating recent progress, identifying critical challenges, and outlining future research directions, this review provides a roadmap for the development of next-generation multifunctional magnetic soft-fiber technologies.