Highly flexible all-nonwoven piezoelectric generators based on electrospun poly(vinylidene fluoride)

Abstract

Acoustic energy is a sustainable and clean form of energy that is always being generated and wasted in our environment. Acoustic energy harvesting technology is a very promising substitute for fossil fuels and can serve as a suitable power supply for small electronic devices, owing to the high efficiency of piezoelectric devices. Thus, many studies have investigated the conversion of sound energy into electricity for power generation. In this study, we successfully fabricated an all-nonwoven polymer-based piezoelectric generator with a high acoustic energy conversion efficiency and high flexibility. A dispersion of single-walled carbon nanotubes (SWCNTs) was sprayed onto electrospun poly(vinylidene fluoride) (PVDF) webs to produce flexible and durable electrodes. The thickness and flexibility of the PVDF web used as the active piezoelectric layer were controlled by the spinning time. The effect of flexibility on frequency response, sound pressure response, output power, and energy harvesting characteristics was investigated by observing sound wave-induced vibration behavior and evaluating the output characteristics of the generators. The all-nonwoven polymer-based generator with the highest flexibility showed the highest output voltage overall due to its excellent vibration characteristics. Due to its effectiveness and durability suitable for acoustic energy harvesting, this all-nonwoven polymer-based generator can be useful for a wide range of applications, such as wearable electronics and large area flexible devices.