Output Performance Enhanced Triboelectric Nanogenerators Induced by Magnetic Ink Trapping Property Act as Wearable Sensors

Abstract

The demand for clean-energy collection has gradually increased in recent years, making triboelectric nanogenerators a promising research field, because of their advantages in convenient manufacturing, diversified materials, and diverse synthesis and modification possibilities. However, recent studies indicate that charge decay, a major limiting factor in the triboelectric output, prevents the induced charge from combining with the bottom electrode, leading to charge loss. The use of charge-trapping sites to retain the induced charge generated during the friction process is an important solution in the field of triboelectric nanogenerator research. This study proposes the use of an elastic ink with macroscopic magnetism as trapping sites by coating the ink as dots between the polytetrafluoroethylene (PTFE) dielectric layer and the electrode layer. Nickel particles in the magnetic ink are doped into the system as microcapacitors, which prevent the combination of the friction layer and induced charges on the back electrode. Because the nickel itself can be used as a charge-potential trap to capture the charge introduced by the chargeinjection process, the charge can be maintained for a long time and achieve a long-term high-output state. The output voltage was more than 6 times that of the reference group without the magnetic-ink coating after 3 h. The results provide a reference direction for research on preventing charge decay and trapping charges in triboelectric nanogenerators.

Advances in magnetic-assisted triboelectric nanogenerators: structures, materials and self-sensing systems

“…This entailed applying elastic ink droplets containing magnetic nickel onto the rear surface of the dielectric layer of PTFE and nylon films. The Ni particles in the magnetic ink act as microelectronic containers, preventing the binding of induced charges on the tribo-layer and its electrode, thus achieving long-term high-output states [150]. In a separate study, Seol et al presented a ferromagnetic fluidbased TENG device (figure 7(e)) that encapsulated TENG and EMG components in a single integrated structure [151].…”