Fabrication and Characterization of Flexible PVDF-TrFE-BaTiO3-Ti3C2 MXene-Based Composite Multi-Morphs: Towards Advancing Electroactive Materials for Wearable Biomedical Technologies

Lead-based perovskite oxides have been used as sensors, actuators, and transducers, for sound generation, mechanical detection, optical instruments, microscopes, and many more technologies. Electro-polymers such as PVDF, and PVDF-TrFE-based structures have also been used in several applications towards the development of flexible electroactive multi-morph systems for biomedical applications, but these systems have lower piezoelectric strain coefficients as compared to those of their lead-based piezoceramics. Though lead-free-based ceramic and electroactive polymer composites have been explored, their property-performance characteristics are not comparable to those of electro-active ceramics. The following work investigates the developments of non-toxic PVDF-TrFE-BaTiO3-Ti3C2 MXene-based lead-free alternatives to perovskite oxide applications by including the MXene phase to combat the weaker piezoelectric strain coefficients. Effective bulk electrical property optimization was achieved by varying the volume fractions of the MXene phase. The MXene phase's volume fraction will have a 1% to 5% variance and the PVDF-TrFE phase will also vary to accommodate the change of the MXene phase, while the volume fraction of the BaTio3 phase will be kept constant at 30%. The dielectric constant, capacitance, impedance, and piezoelectric properties of the samples were measured using an impedance analyzer, and a piezometer. The results were analyzed based on the volume fraction of MXene compared to control values of only PVDF-TrFE and 70% PVDF-TrFE to 30% BaTiO3 to evaluate the change in electrical and dielectric properties. The impedance and dielectric spectra of the nanocomposites were measured across a frequency range of 20 Hz to 10 MHz. The microstructural properties and cross-sections of the thin films were examined using a Scanning Electron Microscope to measure porosity to see if it correlates with any electrical property. The composite's high sensitivity and electron transport properties suggest potential applications in biomedical devices operating at both low and high frequencies without the risk of using any lead-based materials.