Multifunctional Tribovoltaic Coating for Self‐Powered In Situ Sensing with Exceptional Tribological Robustness and Charge Transport

Abstract Tribovoltaic nanogenerators, capable of generating direct current through friction‐induced carrier migration, represent a promising frontier in self‐powered sensing. However, conventional semiconductor materials face critical limitations in mechanical properties and cost‐effectiveness in real applications. Here, an amorphous hydrogenated carbon‐based multifunctional tribovoltaic coating (M‐TC) is introduced by physical‑vapor deposition that simultaneously delivers semiconducting functionality and exemplary tribological robustness. Comprehensive ball‐on‐disk tribological tests revealed a strong correlation between tribological behavior and electrical output, with the M‐TC exhibiting an ultralow friction coefficient of 0.066 under self‐lubricating conditions and a notably high peak power density of 1.18 kW m −2 . First‐principles simulations further confirmed the coating's exceptional structural stability and efficient electron transport capabilities at the nanoscale. Practical integration of the M‐TC into bearing systems demonstrated significantly reduced friction torque, minimized vibration, and effectively suppressed temperature rise, validating its real‐world advantages. Moreover, spectral analysis of the generated electrical signals enabled robust and real‐time monitoring of bearing anomaly detection with exceptional sensitivity (linearity R 2 = 0.9997). This study significantly advances multifunctional tribovoltaic coatings, providing a viable pathway toward the development of components with integrated protective and sensing functionalities suitable for next‐generation intelligent manufacturing systems.