Fig. 4
Research result of the triboelectric voltage output signal and the vibration amplitude from a electrode #2, b electrode #5, and c electrode #8, which was measured by LDV system and oscilloscope in the frequency ranging from 20 to 3000 Hz, and a distribution of the vibration displacement and the triboelectric voltage output signal were closely overlapped all over the frequency bandwidth. d Experimental results of the relationship between the electrode number and the local resonance frequency of the PTFE membrane