Flexible PVDF/ZnO/rGO and PVDF/ZnO/CNT electrodes designed for piezoelectric nanogenerators

The newly interesting topics about wearable electronics and smart textiles usually require a pair of flexible conductive electrodes. As far as conductivity is concerned, carbon nanomaterials are of particular interest. This study aimed to design flexible piezoelectric nanogenerators (PENGs) with carbon-based electrodes. Here, two different types of electrodes were fabricated using composites of polyvinylidene fluoride (PVDF) with single-walled carbon nanotubes (CNT) in one and reduced graphene oxide (rGO) in the other. The PENGs were structured by placing a piezo-active nanofibrous mat of PVDF and ZnO nanopowder between each pair of electrodes. The optimal PENGs were then integrated using polydimethylsiloxane (PDMS). The piezoelectric voltage constant (g33) of rGO-contained samples was approximately 5 times higher than that of samples with CNT. However, the opposite results were obtained in their tensile stress by a declining factor of 1.35. The piezoelectric sensitivity was enhanced by 5–9 % after integration. Finally, these flexible PENGs can be promising candidates for harvesting energy through textiles.