Cellulose Beyond Substrates: Emerging Functional Roles in Sustainable Advanced Electronics

Cellulose, the most abundant natural polymer, is emerging as a versatile biomaterial platform for sustainable advanced electronics beyond its conventional role as a passive substrate. Its hierarchical fibrillar architecture and hydroxyl-rich chemistry enable unique combinations of mechanical compliance, interfacial reactivity, ionic transport, and optical transparency. This perspective highlights cellulose as a multifunctional system spanning structural and interfacial integration, ionic-electrochemical behavior, and optoelectronic interfaces, which together underpin its growing relevance in flexible, energy, and transparent electronic technologies. However, intrinsic coupling between hydration sensitivity, conductivity limitations, and structural stability defines key design trade-offs that must be addressed for practical implementation. Future progress will rely on transforming these inherent characteristics into tunable design parameters through hierarchical structuring and sustainable hybridization strategies, enabling cellulose-based architectures for next-generation environmentally adaptive electronics.