An optimized design for dielectric layer charges distribution towards high-performance output of TENG and its multifunctional applications

In the Internet of Things (IoT) era, self-powered sensors provide an effective way to solve the energy problem. In this paper, a V₂CTx-BaTiO₃-V₂CTx@Ecoflex (VBV) composite dielectric layer membrane with a sandwich structure is proposed and used to construct self-powered flexible sensor devices. Due to the charge trapping ability of the V₂CTx layer with abundant functional groups and the charge storage ability of the BaTiO₃ layer, the charge loss of the device during contact- separation gets reduced, which improves the TENG output performance. The peak voltage of VBV-TENG is up to 550 V, which is 1.6 and 1.8 times higher than the output of TENG based on V₂CTx and BaTiO₃ doping in separate, respectively. The VBV-TENG can light up to 400 LEDs under tapping and achieve a power density of 12.8 W/m² with optimal impedance matching. It can not only be used as an energy-harvesting device, but has also been shown to be a self-powered pressure sensor with an ultra-high sensitivity of 23.7 V/kPa, which can be used for the monitoring of human movement physiological signals. Finally, a self-powered flexible material recognition sensor based on the VBV composite dielectric layer is constructed by rational design, which realizes the effective recognition of various materials. This study provides a new pathway for design of high-performance dielectric layer of TENG, and explores the application of realizing multifunctional self-powered sensors based on TENG.