Enhanced triboelectric effect using functionalized multiwalled carbon nanotube-coated fiber mats for biomechanical energy harvesting

Triboelectric nanogenerators (TENGs) have emerged as a cutting-edge technology for developing self-powered wearable electronic devices. In this study, TENGs were fabricated using two fiber mats: forcespun polytetrafluoroethylene (FS-PTFE) microfibers and electrospun polyvinyl alcohol (ES-PVA) nanofiber (NF) mats. The FS-PTFE mats were coated with functionalized multiwalled carbon nanotubes (MWCNTs). Functionalized MWCNTs were dispersed in water-based solutions containing three different surfactants—sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and Triton X-100 to enhance fiber interaction. The NF mats were subsequently immersed in aqueous systems. The surfactant facilitated the uniform deposition of COOH-MWCNTs onto the FS-PTFE fibers, serving as a negative layer, while ES-PVA mat functioned as a positive layer for TENGs. The fabricated fiber systems were characterized using FESEM and AFM with energy dispersive XRD and FTIR. Electrical testing revealed 240% improvement in voltage performance for MWCNT-coated fibers compared to uncoated fibers. The specimen without surfactant exhibited the highest peak-to-peak values of 284 V, 2.29 µA, and 0.65 mW at a frequency of 140 BPM. Further testing demonstrated the TENG's charging capacity, durability, stability, and applicability as a sensor in various biomechanical motion scenarios. These findings underscore the potential of the developed TENGs for cost-effective, long-term use in self-powered wearable energy harvesting and sensory applications.