Design, Fabrication, and Application Study of Droplet Tube Based Triboelectric Nanogenerators

The invention of triboelectric nanogenerators (TENGs) provides an effective approach to the sustainable power of energy. Liquid-solid interface-based TENGs have been researched in virtue of less friction for harvesting energy from raindrops, rivers, and oceans in the form of water flows. However, TENGs based on droplet tubes have been rarely investigated. In this study, we proposed a new droplet tube-based TENG (DT-TENG) with free-standing and reformative grating electrodes. Both straight and curved DT-TENGs have been designed and fabricated including straight and curved TENG at different inclination angles. The electric properties of DT-TENGs have been evaluated and different materials and hydrophobicity treatments for the tubes have been studied. Initial studies on different liquids demonstrated significant electricity output differences to recognize polar and nonpolar solvents. This DT-TENG was also made into a smart fishing float that can recognize different movement speeds brought about by different weights and generate corresponding electric signals to remind the angler. Furthermore, flexible PVC helix TENG demonstrated similar performance under both straight and helix situations. This study provides a foundation and academic insight into the design and fabrication of droplets based TENGs for energy harvesting in smart cities.