Extended Data Fig. 6: Effect of the spatial location and width of the aluminium electrode on electricity generation.

a, The spatial location of the aluminium electrode was changed, keeping the impact location fixed. In this way, the spacing between the droplet centre and the electrode can be tailored. Insets marked with 1, 2, 3, 4 refer to the four different locations of the aluminium electrode on the PTFE surface. The results show that regardless of the electrode location, the output voltage is constant, suggesting that electricity generation is not sensitive to electrode location. Data are means ± s.e.m. For each mean, the total number of measurements is ten. b, The output voltage does not depend on the size of the aluminium electrode. This makes sense because the source of electricity generation is the electrostatically induced charge on the ITO, rather than on the aluminium. Data are means ± s.e.m. For each mean, the total number of measurements is ten.