Cellulosic Flexible Electronic Materials: Recent Advances in Structural Design, Functionalization, and Smart Applications

Rapid advancement of flexible electronics has generated a demand for sustainable materials. Cellulose, a renewable biopolymer, exhibits exceptional mechanical strength, customizable properties, biodegradability, and biocompatibility. These attributes are largely due to its hierarchical nanostructures and modifiable surface chemistry. This paper systematically reviews the molecular and structural properties of cellulose, clarifying the relationships between structure, performance, and application for its multifunctional uses in next-generation devices. Advanced processing techniques-including 3D printing, freeze-drying, and chemical modifications-facilitate the integration of cellulose with conductive polymers and nanomaterials to create multifunctional composites. These innovations are pivotal for breakthroughs in ultra-sensitive flexible sensors, self-powered nanogenerators, high-capacity energy storage systems, and biomimetic electronic skins. The environmental adaptability and tissue compatibility of these composites make them particularly suitable for wearable health monitors and biodegradable electronics. Challenges related to scalability and multifunctional integration are being addressed through molecular engineering and sustainable manufacturing practices approaches like solvent-free 3D printing. By converging nanotechnology with principles of a circular economy, cellulose-based systems are redefining sustainable electronics and bridging human-centered design with eco-intelligent solutions.