3, Portland State University, Portland, Oregon, United States
Three-phase, lead-free, biocompatible barium titanate-epoxy-zinc oxide (BaTiO3-Epoxy-ZnO) electroactive composite films were prepared. The volume fraction of the BaTiO3 phase was held constant at 0.4, while the volume fraction of the ZnO phase was varied from 0.01 to 0.10. The dipoles of the electro-active phases were aligned using a plasma-microdischarge (Corona) poling technique. The piezoelectric strain coefficients, dielectric constant, dielectric loss tangent, capacitance, impedance, resistance, and conductance of the samples were measured and compared as a function of poling regime. The impedance and dielectric spectra of the composites were recorded over a frequency range of 20 Hz to 10 MHz. The fractured surface morphology and distribution of the phases were observed with the aid of Electron Dispersion Spectroscopy (EDS) and a Scanning Electron Microscope (SEM), which showed the inclusions embedded in the epoxy matrix. The electromechanical properties of the composites were optimized towards the development of sensors and energy harvesters for self-powered pace makers.