High Power Density Tower-like Triboelectric Nanogenerator for Harvesting Arbitrary Directional Water Wave Energy.

Wave energy is one of the most available energy sources in oceans. In this work, a design of high power density triboelectric nanogenerator (TENG) based on a tower structure is proposed for harvesting wave energy from arbitrary directions. Such tower-like TENG (T-TENG) consists of multiple units made of polytetrafluoroethylene balls and three-dimensional printed arc surface coated with melt adhesive reticulation nylon film. The power generation model coupled with the kinetic model for the T-TENG is proposed and discussed. The T-TENG can effectively convert arbitrary directional wave energy into electrical energy by utilizing charged balls rolling on an optimized arc surface due to ocean wave excitation. In addition, it is found that the power density of the present T-TENG increases linearly from 1.03 W/m3 to 10.6 W/m3 by increasing the units from 1 to 10 in one block. This supports that the power density of the T-TENG increases proportionally with the number of units connected in parallel without rectifiers due to its distinctive mechanism and structure. Therefore, the design of T-TENG provides an innovative and effective approach toward large-scale blue energy harvesting by connecting more blocks to form T-TENG networks.