Fig. 7. Impulse excitation characterization of the W-TENG with eight power generation units connected in parallel for human motion.

a Comparisons of the output voltage waveforms for different deformation forms, such as horizontal pressing, vertical tapping and lateral bending; b Enlarged view of the open-circuit voltage waveforms for the vertical tapping motion; c snapshots of a power generation demonstration in which LEDs are lit up by horizontal pressing and vertical tapping; d output voltage waveforms for different hand pressing frequencies in the horizontal axial direction; e enlarged view of output voltage waveforms; f output performance demonstration in which the W-TENG is installed in shoes during walking and jogging