Fig. 3.

a, A font view of the setup used to measure the voltages of the tip of static electricity generator at different heights between 6 cm and 25 cm b, Measured voltage vs the distance of the electrode from the ground (n = 3). Note that only relative values should be considered in Fig. 3b as the measurement was performed at a larger distance from the tip of the gun than the one that is used to read accurate values for avoiding breaking the probe (see materials and methods for the details). c, A scheme showing the setup used to measure voltages with a double layer electrode with or without ceramic legs. d, The measured voltages with or without legs vs time.