Spherical triboelectric nanogenerator integrated with power management module for harvesting multidirectional water wave energy

With the increasing deterioration of the natural environment, exploiting clean and renewable energy has become the top priority of scientific research today. One of the most prospective routes is to harvest water wave energy using triboelectric nanogenerator (TENG). In this work, a spherical TENG based on spring-assisted multilayered structure was fabricated to collect multidirectional water wave energy, and a power management module (PMM) was integrated to manage the output energy. The output performance of the TENG device was found to be controlled by the water wave frequency, amplitude, and orientation angle between the triggering direction and middle plane. Furthermore, with the PMM, the spherical TENG could output a steady direct current (DC) voltage on a resistance, and the charging speed to a supercapacitor was improved by 100 times. The power-managed performance of the whole TENG was also influenced by the circuit connection configurations among multilayered TENGs. A digital thermometer and a water level detection/alarm system were successfully driven by the power-managed TENG as the demonstrated applications. This work not only provides a type of spherical TENG capable of harvesting multidirectional water wave energy, but also effectively manages the output energy for practical applications toward blue energy. Our study demonstrates a typical example of how to build a self-charging power pack that can effectively use random energy in a regulated manner.