Triboelectric Nanogenerator-Based Near-Field Electrospinning System for Optimizing PVDF Fibers with High Piezoelectric Performance

Abstract

Electrospinning is an effective method to prepare polyvinylidene fluoride (PVDF) piezoelectric fibers with a high-percentage β phase. However, as an energy conversion material for micro- and nanoscale diameters, PVDF fibers have not been widely used due to their disordered arrangement prepared by traditional electrospinning. Here, we designed a near-field electro-spinning (NFES) system driven by a triboelectric nanogenerator (TENG) to prepare PVDF fibers. The effects of five important parameters (PVDF concentration, needle inner diameter, TENG pulse DC voltage (TPD-voltage), flow rate, and drum speed) on the β phase fraction of PVDF fiber were optimized one by one. The results showed that the electrospun PVDF fibers had uniform diameter and controllable parallel arrangement. The β phase content of the optimized PVDF fiber reached 91.87 ± 0.61%. For the bending test of a single PVDF fiber piezoelectric device, when the strain is 0.098%, the electric energy of the single PVDF fiber device of NFES reaches 7.74 pJ and the energy conversion efficiency reaches 13.5%, which is comparable to the fibers prepared by the commercial power-driven NFES system. In 0.5 Hz, the best matching load resistance of a PVDF single fiber device is 10.6 MΩ, the voltage is 6.1 mV, and the maximum power is 3.52 pW. Considering that TENG can harvest micromechanical energy in the low frequency environment, the application scenario of the NFES system can be extended to the wild or remote mountainous areas without traditional high-voltage power supply. Therefore, the electrospun PVDF fibers in this system will have potential applications in high-precision 3D fabrication, self-powered sensors, and flexible wearable electronic products.

Review on Polyvinylidene Fluoride-Based Triboelectric Nanogenerators for Applications in Health Monitoring and Energy Harvesting

“…The TENG can recycle noise energy into usable electricity, noise reduction in jet engines, IoT, and selfpowered sensors are a few examples of sound energy harvesting nanogenerator applications. 192,193…”

Achieving Ultra‐High Voltage (≈10 kV) Triboelectric Nanogenerators

“…[11,12] Furthermore, TENG has a born character of low current that subjects to the transferred charges in one cycle, greatly guaranteeing the safety of personnel and instruments. [13] Owing to the merits of portability, controllability, safety, and high efficiency, TENGs-based high voltage power sources have been utilized in mass spectrometry, [14] fabricating of electro-spun nanofibers, [15,16] protection, [17,18] producing triboplasma, [19,20] and negative air ions. [21] However, all of these high voltage power sources are achieved based on the working types of TENG including contact-separation mode, sliding mode, and freestanding mode, whose application will be restricted by the wiring problem.…”

Adaptable Networks with Semiorthogonal Two-Stage Polymerizations Enabled by Sequential Photoinitiated Thiol–Ene and Disulfide–Ene Reactions

“…17,18 Beyond mechanical property programming, spatial patterning of the refractive index is often utilized in two-stage systems for applications such as holographic gratings. 19 However, in these applications, two-stage polymer formulations suffer from several limitations, including phase separation and unwanted diffusion of mobile species during the reaction, leading to haze and limited transparency in optical materials and diminishing the fidelity of patterning or shape programming. 20−23 To mitigate the aforementioned challenges, the formation of covalent bonds between the monomer components involved in both curing steps has proven to be extremely valuable for improving the fidelity of second-stage photopolymerizations.…”