Enhanced clean energy harvesting using polyurethane/polyvinylidene fluoride nanofiber-based triboelectric nanogenerator with pumping effect

Abstract

Triboelectric nanogenerators (TENGs) operating in contact-separation mode present a promising avenue for harvesting low-frequency mechanical energy, such as that generated by hand tapping. However, their practical application has been limited by low surface charge densities, resulting in suboptimal performance. In this study, we introduce a novel material concept employing flexible and thin nanofiber layers of PU918/QAS and PVDF/graphene to enhance the performance of triboelectric pairs. We developed an integrated device designed specifically to harvest mechanical energy from hand tapping, a common form of body movement. To amplify the output charge, we utilized a charge pump effect that continuously accumulates charge in a floating layer. Leveraging this effect, the nanogenerator achieved an open-circuit voltage exceeding 160 V and a surface charge density of 240 mu C m- 2. The pumping effect is analyzed through stage movement synchronization, underscoring the critical importance of the order in which individual stages open and close. Furthermore, we designed an energy harvesting system capable of efficiently accumulating the produced electrical energy. These findings confirm the feasibility of our approach for practical applications, particularly in low-energy consumption IoT systems.