Recent advances in biogenic self-powered sensors: material, mechanism and application

• Comprehensive review on the integration of biopolymers (cellulose, chitosan, alginate, silk) into self-powered sensors, emphasizing their sustainability, biocompatibility, and tunable properties. • In-depth analysis of energy conversion mechanisms: moisture-enabled, thermoelectric, triboelectric, piezoelectric, and electromagnetic harvesting, with a focus on biopolymer-based systems. • Advanced material strategies including nanocomposite engineering, surface functionalization, and hierarchical structuring to enhance energy harvesting and sensing performance. • Diverse applications in wearable electronics, industrial monitoring, environmental sensing, and biomedical devices, demonstrating real-world viability of biogenic self-powered systems. • Future outlook highlights challenges and directions such as multiscale optimization, green manufacturing, extreme environment adaptation, and interdisciplinary integration for next-generation intelligent sensors. The rapid advancement of Internet of Things (IoT) and flexible wearable technologies is driving demand for miniaturized, sustainable, and self-powered sensors. Self-powered sensing which directly converts environmental stimuli such as temperature, humidity, and mechanical forces into electrical signals without external power. Biomass-based polymers (e.g., cellulose, chitosan, silk fibroin, alginate) have emerged as ideal platforms for next-generation self-powered sensors owing to their natural abundance, biodegradability, eco-friendliness, and tunable nanostructures. Crucially, these biopolymers not only generate electricity independently through triboelectrification and moisture-induced mechanisms but also form high-performance composites with inorganic nanomaterials. These hybrids significantly enhance mechanical robustness and power output while retaining inherent bio-sourced advantages. This energy-harvesting process intrinsically transduces target signals into electrical responses, enabling self-powered sensing. This review systematically examines fundamental biopolymer properties and the principles of harvesting humidity, thermal, and mechanical energy. It further explores surface modification and nanocomposite engineering strategies to achieve energy-harvesting and self-powered sensing capabilities. Finally, we outline future directions focusing on multiscale performance optimization via micro/nanostructural design, green scalable manufacturing, applications in extreme environments, and interdisciplinary frameworks, ultimately bridging self-powered technology with sustainable natural materials to advance the development of intelligent sensing in the future.