Wood-based triboelectric nanogenerators: From structural design to performance optimization and applications

• Analyzes triboelectric charge formation in wood and how composition, moisture, and surface chemistry influence output performance. • Reviews chemical and mechanical wood modifications that enhance surface charge density and dielectric constant. • Introduces six optimization strategies to improve triboelectric properties of WB-TENG. • Demonstrates application scenarios of WB-TENG in sensors, wearables, and smart systems. Wood-based triboelectric nanogenerators (WB-TENGs) have emerged as a promising sustainable energy harvesting technology, leveraging the hierarchical structure, renewability, and tunable surface properties of wood. This review systematically summarizes recent advances in WB-TENGs, focusing on their fundamental mechanisms, material modifications, structural designs, and functional applications. By leveraging the inherent porosity, anisotropy, and tunable surface chemistry of wood, WB-TENGs facilitate efficient contact electrification and enhanced charge retention, enabling the conversion of low-frequency mechanical energy into electricity. Key strategies such as nanocomposite integration, surface engineering, and modular system design are discussed for enhancing output performance, environmental stability, and mechanical durability. Despite significant progress, challenges remain in optimizing performance under variable conditions, scaling up production, and understanding charge transport mechanisms. This review also outlines future directions, including hybrid material systems, machine learning-assisted optimization, and scalable manufacturing, to bridge laboratory research and practical deployments. WB-TENGs hold great potential as sustainable energy solutions for IoT devices, self-powered sensors, and green electronics.