Ultrasonic-assisted ultrafast fabrication of polymer nanowires for high performance triboelectric nanogenerators

Based on the coupling effect of triboelectrification and electrostatic induction, triboelectric nanogenerators (TENGs) can convert mechanical motions into electricity and electrical signals for mechanical energy harvesting and self-powered sensors, respectively. Polymer films with nanowires could significantly enhance the output performance of TENGs. Here, we introduce a novel ultrasonic-assisted ultrafast approach of fabricating vertical polymer nanowires for TENGs application. Benefited from the high temperature generated from ultrasonic-driven friction between the constituent materials, polymer can be fast melted and absorbed into the nanochannels of template. The vertical polymer nanowires will therefore be formed on the surface of polymer film by removing template for further serving as triboelectric materials. By changing the ultrasonication time, polymer nanowires with different length (0.5 to 58 μm) and aspect ratio (2 to 232) have been controllably prepared. The assembly TENGs based on PVDF film with nanowires are capable of generating open-circuit voltage of 230 V and transferred charge of ~79 nC. The devices are utilized to harvest mechanical energy with electric output of 153 V and 23 μA, which can power up 78 green LEDs and capacitors. This study not only presents a novel ultrafast fabrication approach of polymer nanowires with aspect-ratio controllability and universal suitability, but also demonstrates the polymer nanowires’ application in mechanical energy harvesting of TENGs with enhanced performance.