Recent advances in multidimensional (1D, 2D, and 3D) Joule heating devices based on cellulose: Design, structure, application, and perspective

The demand for flexible electric heating devices has increased due to technology advancement and improved living standards. These devices have various applications including personal thermal management, hyperthermia, defrosting, agricultural heating film, and oil-water separation. Joule heat, generated by electric currents, is commonly used in electrical appliances. To incorporate Joule heating into flexible electronics, new materials with excellent mechanical properties are necessary. Traditional polymers, used as reinforcements, limit the continuity of conductive networks in composites. Therefore, there is a need to develop flexible Joule thermal composite materials with enhanced mechanical strength and conductivity. Cellulose, a widely available renewable resource, is attracting attention for its excellent mechanical properties. It can be used as a dispersant and reinforcing agent for conductive fillers in cellulose-based composites, creating highly conductive networks. Various forms of cellulose, such as wood, nanocellulose, pulp fiber, bacterial cellulose, cellulose paper, textile clothing, and aramid fiber, have been utilized to achieve high-performance Joule thermal composites. Researchers have achieved excellent mechanical properties and developed efficient electric heating devices by designing cellulose-based composites with different structures. The scalable production methods enable large-scale application of cellulose-based devices, each with unique advantages in 1D, 2D, and 3D structures. This review summarizes recent advancements in cellulose-based Joule thermal composites, providing insights into different structural devices, and discussing prospects and challenges in the field.