V2CTX-MXene-functionalized fluoropolymer composite nanofibrous mat-based high-performance triboelectric nanogenerator for self-powered human activity and posture monitoring

Since triboelectric nanogenerators (TENG) are receiving attention as a promising technology in the domain of self-powered sensors for human activity monitoring and human machine interfaces, significant research is being conducted to enhance their performance and reliability. Herein, a novel V2CTX@poly(vinylidene-fluoride-co-hexafluoropropylene) composite nanofibrous (VPCN) mat was developed as a highly electronegative and stable tribolayer to improve the overall triboelectric performance. An abundant presence of functional groups (-F, -O, and -OH) on the V2CTX surfaces enhanced electronegativity, while formation of micro-capacitor networks into the polymer matrix enhanced the dielectric property along with the electron-trapping capacity, which reduced charge loss. The fabricated VPCN-TENG coupled with polyethylene oxide (PEO) nanofibrous mat exhibited a peak power-density of 18.2 W/m2, which was 3.5-fold higher than the pristine PVDF-HFP nanofibers-based TENG. The remarkable electrical output of the VPCN-TENG facilitated the transformation of biomechanical energy from various human motions into electrical power capable of powering commercial electronics such as stopwatches and thermo-hygrometers. Furthermore, the VPCN-TENG was successfully demonstrated as a self-powered pressure sensor with an extraordinary sensitivity of 25.17 VkPa-1 (1-42 kPa). In addition, the VPCN-TENG was used to fabricate a smart-belt as a self-powered motion sensor for monitoring various human activities such as walking, running, jumping, and posture monitoring during sitting and cycling. These findings offer valuable insights for designing high-performance TENG, fostering development of self-sustainable wearable electronics and advancements in self-powered sensors.