Influence of material grading and compositional platinum profile on the functionally graded piezoelectric bridge structure

Bridge transducers are square or rectangular cymbals that have been proven to be a promising design for piezoelectric energy harvesting in the presence of high-impact loads. This study investigates the effect of compositionally graded platinum and material exponents on the performance metrics of a flex tensional bridge structure. A functionally graded piezoelectric material is created here by incorporating a compositionally graded Pb[Zr_xTi1−_x]O₃/platinum material (Pb[Zr_xTi1−_x]O₃/platinum) with a polymer of -(C₂H₂F₂)_n-. The multiphysics bridge structured model is solved using finite element analysis. The biokinetic energy is generated by footsteps with loads that are 1.5–3 times the body weight, and thus an impact load of 1500 N is considered in this study. The performance metrics in terms of voltage and power are scrutinised using the electromechanical model in order to attain maximum output at optimal settings. The optimal grading exponent values are determined by the platinum concentration as well as other functional factors. It is discovered that the power law-driven grading index improves bridge functionally graded piezoelectric material performance regardless of changes in other operating parameters. Although platinum impairs Pb[Zr_xTi1−_x]O₃/platinum performance but synergising the composite material with the grading index enhances the performance metrics percentage of functionally graded piezoelectric material over the respective Pb[Zr_xTi1−_x]O₃/platinum material. This research establishes the relevance of synergism on the electromechanical features and performance of bridge transducers, and is applicable to any bonded piezoelectric device, whether it is an energy harvester, actuator or sensor.