Fig. 13.

Output performance characteristics of the 3DP-TENG proposed by Tian et al. [147]: a short-circuit current, b induced charge c open-circuit voltage with twelve different pairs of fraction layers, d output current and power density with the external resistance e, the transformed short-circuit current, and f rectified short-circuit current [147]. Electrical performance of the 3DP-NMEH proposed by Hong et al. [148] under various test conditions: The induced charge density and powder density under the vertical operational mode and various: g amplitudes (2–10 mm) h frequencies (1–3 Hz), charge and powder densities achieved by the device under rotational working mode and various: i Teflon volume ratios (30–70%) j speeds (120–280 RPMs) k durability test under vertical operational mode over 10,000 operational cycles [148] (Images are re-used with the permission of the publisher)