Significantly Enhanced Poling Efficiency of Piezocomposites by Tuning Resistivity of a Polymer Matrix

Although the ability to convert biomechanical vibrations into electric energy has been demonstrated in organic-inorganic piezocomposites, it is challenging to improve their piezoelectric properties owing to insufficient electric field poling. Here, we propose a facile and effective approach to enhance the poling efficiency of a barium calcium zirconate titanate/polydimethylsiloxane (BCZT/PDMS) composite by introducing copper nanowires (Cu NWs) to tune the resistivity of the PDMS matrix. The Cu NW-modified PDMS weakens the resistivity mismatch between the BCZT filler and the PDMS matrix, allowing a higher poling electric field to be applied to the BCZT filler during poling. As a result, the BCZT/Cu-PDMS piezocomposite exhibited a high piezoelectric quality factor (d₃₃ × g₃₃) of 2.58 pm²/N, which was about 7 times higher than that of BCZT/PDMS (d₃₃ × g₃₃ = 0.38 pm²/N). Moreover, BCZT/Cu-PDMS showed a much higher power density (3.18 μW/cm²) and a faster charging capability. This composite approach of introducing metal nanowires can be considered as a generic poling-improvement method that can be extended to other organic-inorganic piezocomposite systems.