Acoustic-electric conversion and piezoelectric properties of electrospun polyvinylidene fluoride/silver nanofibrous membranes

Herein, a novel sound energy acquisition device based on a flexible electrospun polyvinylidene fluoride (PVDF) nanofibrous membrane was developed. Effects of electrospinning and the addition of silver nanoparticles (AgNPs) on the crystal structure and piezoelectric properties of the PVDF nanofibrous membranes were examined. Electrospinning and the addition of AgNPs effectively induced the formation of the beta-phase and increased the piezoelectricity. The piezoelectric electrospun PVDF samples were crucial for converting sound energy into electric potential and absorbing sound waves. Moreover, the use of piezoelectric shunt damping reduced the sound transmission at low frequencies. Therefore, the electric energy generated in the low-frequency region was higher than in mid- and high-frequency regions. The electric power of PVDF/AgNP was 7.10(-4) W - a significant increase of 40% compared to PVDF without AgNPs (5.10(-4) W) at low frequency. This demonstrates that PVDF/AgNP presents excellent piezoelectric properties and acoustic-electric conversion characteristics. Hence, the piezoelectric PVDF device fabricated herein can not only reduce sound transmission but also convert the sound energy into electric energy. This novel sound energy acquisition device is practical and efficient in various sensing and energy harvesting applications, and will aid in the operation of low-power consumer electronic devices and to maintain a green environment.