Electrothermally activated soft materials: Mechanisms, methods and applications

Responsive soft materials, with unique advantages of light weight, flexibility and large deformation upon activation, have attracted extensive attention in the fields of aerospace engineering, soft robots and human–computer interaction. Electrothermal activation, enabled by the integration of engineered electrical heaters, is emerging as a new dimension in the design of novel functionalities for devices based on responsive soft materials due to its on-demand heating. However, precise control of the activation behavior, performance synergy and multifunctional integration of these devices remain challenging as they involve multidisciplinary collaboration, requiring a comprehensive assessment from materials science, applied physics and advanced manufacturing. Here, we present an overview of various electrothermally activated soft materials in terms of activation mechanisms, unique performance and functionality under electrothermal activation, followed by a discussion of electrical heating design and fabrication techniques, and finally prospective applications of them. Challenges in electrical heater design, multi-physics modeling and integrated fabrication are critically identified. Perspectives for devices based on electrothermally activated soft materials are presented, including multidisciplinary research, conceptual breakthroughs and demand-driven innovations. This review could provide a roadmap for the next stage of research and contribute to accelerating the development of electrothermally activated soft materials towards real-world applications.