Fig. 3: Negative surface charge tuning and standardization for triboelectric materials.
From: Visualization and standardized quantification of surface charge density for triboelectric materials
a–c The (a) output voltage (same sample measured repeatedly, mean ± s.d., n = 5), (b) surface potential (same sample measured repeatedly, mean ± s.d., n = 5. The inset images demonstrate the surface potential of PTFE after 1500, 4500, and 7500 contact-separation, scale bar: 3 mm, color bar: −600 V ~ 600 V), (c) surface charge density (same sample measured repeatedly, mean ± s.d., n = 5. The inset images demonstrate the surface charge density of PTFE after 1500, 4500, and 7500 contact-separation, scale bar: 3 mm, color bar: −1 nC cm−2 ~ 1 nC cm−2) development trend of PTFE-based TENG within 9000 times of contact with Aluminum (2 × 2 cm2, F = 50 N). d Schematic illustrations of the three-electrode system for single polarity charge injection. e Tuning and standardization of negative surface charge on PTFE, (i) −0.58 nC cm−2, (ii) −0.85 nC cm−2 and (vi) −2.86 nC cm−2 (Scale bar: 3 mm). f Schematic illustrations of the neg-PTFE/PTFE triboelectric pair-based TENG. g, h The (g) transferred charge (Qsc), (h) output voltage of neg-PTFE/PTFE triboelectric pair based TENG with different negative surface charge density (2 × 2 cm2, F = 50 N). i. The long-term output stability of neg-PTFE/PTFE triboelectric pair-based TENG (2 × 2 cm2, F = 50 N).
