Enhancing the electrical performance of chitosan-based triboelectric nanogenerator using graphene nanoplatelets for real-time sports application

Triboelectric nanogenerators (TENGs) based on natural polymers gained tremendous interest for their sustainability, eco-friendliness, and biocompatibility. Despite the potential advantages of natural polymer-based TENG sensors, there are still several concerns related to their low output efficiency. This study involves the fabrication of a high-performance and eco-friendly chitosan-based TENG sensor via solvent casting method, using varied concentrations (1 wt%, 2 wt%, and 3 wt%) of graphene nanoplatelets (GNPs) as filler. Comprehensive investigations were conducted into the physicochemical, morphological, thermal, and electrical properties of the chitosan/graphene nanoplatelets (CS/GNPs) composite films. Raman analysis revealed the presence of GNPs in the CS matrix, showing enhanced I_D/I_G values for all the composites compared to pristine GNPs. The deconvoluted N1s XPS spectra unveiled the formation of CS/GNPs composites via amide linkages. Morphological analysis revealed that GNPs were embedded within the CS matrix, which tended to agglomerate at higher GNPs concentrations (3 wt%). Furthermore, the triboelectric performance of the composite films showed an outstanding open-circuit voltage (V_OC), short-circuit current (I_SC), and maximum power density of 166.25 V, 13.56 µA, and 44 mW/m² respectively, at 2 wt% GNPs concentration. The optimized CS/GNPs (2%) TENG sensor was successfully used to track real-time sports activities, distinguishing motions and basketball dribbling with different intensities and heights, respectively. Moreover, soil burial tests indicated promising biodegradation rates within six days, highlighting the significant potential of fabricated triboelectric layers in sustainable wearable technology and real-time activity monitoring.