Room-temperature processed Ag/Pb(Zn_1/3Nb_2/3)O₃–Pb(Zr_0.5Ti_0.5)O₃-based composites for printable piezoelectric energy harvesters

Piezoelectric energy harvesters based on polymer-matrix composites may be an ideal choice for wearable low-power electronic devices with high flexibility and reliability. Herein, we propose an electromechanical energy harvester consisting of 0.4 Pb(Zn_1/3Nb_2/3)O₃–0.6 Pb(Zr_0.5Ti_0.5)O₃ (PZN–PZT) and Ag nanoparticles dispersed in an ultraviolet (UV)-curable polymer matrix. The harvesters were fabricated by printing a viscous paste, followed by curing at room temperature under UV light. Despite the lack of piezoelectric contribution from the UV-cured polymer, the resultant energy harvesting performance was pronounced with ∼8.15 V and ∼862 nA for the optimized composition of 30 vol% PZN–PZT and 2 vol% Ag, corresponding to approximately 9.4 and 6.5-fold increases, respectively, relative to the values of the reference sample. The enhanced piezoelectric energy harvesting was assumed to originate from contributions of the PZN–PZT nanoparticles as the sole piezoelectric material and the Ag inclusions as a source of additional space-charge polarization.