Figure 2.

Characterization of the i-PENG. Photographs of the (a) original and (b) bent i-PENG demonstrating its good flexibility (scale bar = 1 cm). (c) Fourier transform infrared spectra of the PVDF film. Finite-element simulation of the voltage potential distribution for (d) the pure PVDF film and (e) the PVDF film integrated with the PI substrate. V_OC and Q_SC of (f) the pure PVDF film and (g) the PVDF film integrated with the PI substrate. These two different structure devices are driven by linear motors with a frequency of 1 Hz. (h) Statistical comparison of average V_OC and Q_SC of the pure PVDF film and the PVDF film integrated with the PI substrate. (i) V_OC, I_SC, and (j) peak power of the i-PENG at different load resistances. (k) Fatigue test of the i-PENG (~33,750 s, at 2 Hz).