fig1

Figure 1. (A) Schematic illustration of a large-scale array of H-TENG devices deployed on the ocean surface for harvesting “blue energy” from wave motion. (A₁) Photograph of the hemispherical triboelectric nanogenerator (H-TENG). (A₂) Cross-sectional schematic diagram of the hemispherical triboelectric nanogenerator, clearly showing the bottom electrode (Ag), triboelectric layer [P(VDF-HFP)], and top electrode (Cu). SEM images of the device cross-section and the triboelectric layer microstructure: (A₃) A cross-sectional view showing the distinct layers of the bottom Ag electrode and the triboelectric P(VDF-HFP) layer; (A₄) An overview of the triboelectric layer’s morphology; (A₅) A high-magnification image revealing a P(VDF-HFP) microstructure composed of fibers and spherical particles; (B) Photograph of the experimental setup for testing the device via laboratory-simulated wave motion; (C) Preparation of the bottom Ag electrode on the hemispherical substrate; (D) Electrospinning setup for depositing the P(VDF-HFP) nanofiber triboelectric layer. P(VDF-HFP): Poly(vinylidene fluoride-co-hexafluoropropylene); SEM: scanning electron microscopy; TENG: triboelectric nanogenerator; H-TENG: hemispherical TENG.