fig7

Figure 7. Systematic study of the effect of the number of top Cu electrodes and the frequency of water droplet movement on the output characteristics of the H-TENG device: (A) Photograph of an H-TENG device with one top Cu electrode; (B-D) Corresponding current signals of H-TENGs with different numbers of top Cu electrodes (1, 2, and 3 Cu electrodes) at 2 Hz, 3 Hz, and 4 Hz, respectively. (A₁, A₂, A₃) Comparison of current output data of H-TENG devices with 1, 2, and 3 Cu electrodes at different frequencies. Corresponding current signals obtained with a single Cu electrode assembled H-TENG at 2 Hz (B₁), 3 Hz (C₁), and 4 Hz (D₁). Corresponding current signals obtained with a two Cu electrode assembled H-TENG at 2 Hz (B₂), 3 Hz (C₂), and 4 Hz (D₂). Corresponding current signals obtained with a three Cu electrode assembled H-TENG at 2 Hz (B₃), 3 Hz (C₃), and 4 Hz (D₃). H-TENG: Hemispherical triboelectric nanogenerator.