Fig. 4

Equivalent circuits of piezoelectric textiles, and predicted output voltage and power. a Equivalent electric circuit of the woven piezoelectric textiles with conducting yarns as outer electrodes. b Predicted output peak voltage V_out (blue) and power (red) of textiles produced with PA_steel (top: V_i= 4.7 V; C _i  = 0.26 nF; R_i = 4935 kΩ); PA_silver (centre: V_i= 3.5 V; C _i  = 3.5 nF; R_i = 100 kΩ); and PA_silver-wet (bottom: V_i= 3.5 V; C_i = 220 nF; R_i = 41 kΩ); C_i and R_i were measured, V_out and the power were modelled with SPICE software LTspice. c Equivalent electric circuit for a piezoelectric textile connected to an energy harvesting circuit (EHC). d Predicted charging voltage stored in the EHC, V_stored (red), and output voltage V_out (blue); outer electrodes PA_silver-wet (V_i= 3.5 V; C_i = 220 nF; R_i = 41 kΩ; R_load = 1 MΩ)