A Robust Droplet Triboelectric Nanogenerator with Self-Cleaning Ability Achieved by Femtosecond Laser

Abstract

A droplet triboelectric nanogenerator (TENG) has great potential for harvesting the high entropy energy in water. Despite extensive research, it still suffers from low average power density, poor long-term stability, and insufficient flexibility. Here, a porous micronanostructured polytetrafluoroethylene (PTFE) with superhydrophobicity and self-cleaning ability, is generated by femtosecond laser direct processing. The droplet TENG with laser treated PTFE (LT-PTFE) dielectric layer (L-DTENG) can reach a higher output compared with the droplet TENG with a PTFE dielectric layer (P-DTENG). L-DTENG also demonstrated good long-term stability, self-cleaning ability, and flexibility, making it suitable for various applications, including those involving dust and sewage pollution, as well as bending and pressing conditions. Furthermore, a simulation of finite element method (FEM) and an equivalent circuit model are established to understand the working mechanism of L-DTENG. This multifunctional device and theoretical research provide a smart strategy to generate electricity in a complex environment and lay a solid foundation for droplet TENG applications on a large scale.

Recent advances in high charge density triboelectric nanogenerators

“…A similar fabrication process has been extended to create ordered micronano structures on material surfaces (figure 10(b)) [121]. The aim is to produce high-quality micro/nanostructures [122,123]. A TENG was designed as a micro-nano dual-scale structure.…”

Femtosecond Laser Direct Writing of Flexible Electronic Devices: A Mini Review

“…The TENG with micro/nanostructure achieves instantaneous power of 13.99 µW at 10 MΩ and 21 times enhancement in power density than that of the TENG without micro/ nano-structures. Recently, Zhang et al[113] proposed a droplet triboelectric nanogenerator with a superhydrophobic surface and self-cleaning capability fabricated by femtosecond laser direct writing. The droplet TENG with laser treated polytetrafluoroethylene (PTFE) dielectric layer can reach an open-circuit voltage of 60 V and a short-circuit current 3.2 µA after a full pre-charge, which are 3 and 1.5 times improved compared with those of the TENG with a PTFE dielectric layer, respectively.…”

Space Volume Effect in Tube Liquid–Solid Triboelectric Nanogenerator for Output Performance Enhancement

“…Since then, increasing attention has been devoted to the impact of liquid deformation on the output performance of LS-TENG, and this is named the volume effect . On the one hand, although the improvement in the performance of LS-TENG via the volume effect of liquid has been extensively investigated, − almost all of those studies are focused on the transistor-like structure composed of liquid and device. , It still remains to be explored that how the liquid’s spatial distribution influences the output performance of the LS-TENG. On the other hand, unlike the tube LS-TENG (TLS-TENG), which encapsulates the liquid in a tube and can collect external mechanical energy, LS-TENG based on the volume effect mainly focuses on harvesting the mechanical energy of water droplets, limiting its application. − …”