fig6
![Portable green energy out of the blue: hydrogel-based energy conversion devices](https://image.oaes.cc/f745047f-e08d-4f49-b493-e9d51d342ce9/5477.fig.6.jpg)
Figure 6. (A) 59 pairs of p-type PVA/(Fe(CN)63-/Fe(CN)64-) (PPF) and n-type PVA/(Fe2+/Fe3+) (PCF). The polyelectrolytes were sandwiched between two flexible substrates made of polyimide (PI). (B) Voc as a function of ΔT. (C) I-V curve and the corresponding power density of one pair of p-n series. (D) Voc and Isc of 59 pairs of p-n series by using body heat at an ambient temperature of 5 °C.