Fig. 1: Design and properties of the fiber-based MEG.

a Schematic of synergetic strategy of complex coacervation and built-in potential. b Output voltage, c current density, d voltage and current density with variable electrical resistance, and e corresponding power density of the fiber-based MEG at 20% RH. f Performances of the fiber-based MEG and previously reported MEGs. g Comparative radar chart of representative MEGs.