Effects of SWCNT/PVDF composite web behavior on acoustic piezoelectric property

Abstract

Polymeric piezoelectric devices have been widely researched because of their many advantages including flexibility and easy preparation. Most previous studies investigated the conversion of wasted mechanical energy into usable electrical energy. In particular, high flexibility can be applied to a device that converts the acoustic energy discarded from the surrounding environment into usable energy. Such high flexibility can also be used in sound sensors in several fields. In this regard, for diverse application of polymer-based piezoelectric devices, investigation of the correlation between the vibration behavior caused by sound pressure and the energy conversion efficiency is essential. In this study, we successfully manufactured a flexible piezoelectric device with an integrated polymer and an electrode. Poly(vinylidene fluoride) (PVDF) was prepared via electrospinning and used as the active layer material of the piezoelectric device. To establish the electrodes of the composite piezoelectric device, a single-walled CNT dispersion was sprayed onto both sides of the prepared PVDF web.The electric properties and vibration behaviors of the piezoelectric devices were studied to reveal the effect of deformation on the piezoelectric performance, including the output voltage, impedance, displacement, and velocity of the vibrating device induced by sound waves. The output voltages of the devices tended to increase with better vibration characteristics due to sound pressure. In-depth analysis of the deformation behind the energy conversion in piezoelectricity could be important for the development of high-performance acoustic piezoelectric devices, such as wearable electronics, generators, and sensors.