Figure 4.

Performance of the PPE-Fe₃O₄ SC. (a) Evolution of specific capacitance over strains between 0 to 120%, (b) photos of the PPE-Fe₃O₄ SC before, during, and after being stretched, and (c) evolution of specific capacitance over bending angles between 0 to 180°. C₀ and C correspond to specific capacitances before and after stretching or bending, respectively. (d) Circuit diagram: charge the PPE-Fe₃O₄ SCs in series by a power source, and then cut off the power. (e) The voltage curve of the four SCs in series: V4 represents the voltage of four SCs, V2 represents the voltage of two SCs, and V1 represents the voltage of one SC. (f) The PPE-Fe₃O₄ SCs connected in series lighted the LED.