Fabrication of biodielectric capacitors and improvement of their dielectric properties for biomedical applications

In thesis study, nanostructured hydroxyapatite bioceramic materials and thin film coatings have been coated on Ti-6Al-7Nb substrate by hydrothermal method. Hydroxyapatite films have been grown depending on the production conditionss and dopant materials. Stronium (Sr), zinc (Zn) and nickel (Ni) doped hydroxyapatite films have been grown on Ti-6Al-7Nb substrate for 10, 16 and 22 h, reacton time. The dielectric and structural properties of the synthesized films have been investigated. The structural and dielectric properties of the bioceramic materials have been investigated by scanning electron microscopy (SEM), FT-IR analysis and impedance spectroscopy, respectively. The FT-IR analysis confirms the chemical composition of synthesized bioceramic materials. The capacitance, impedance, conductivity and dielectric properties of Ti-6Al-7Nb/bioceramic/Ti-6Al-7Nb capacitors in the 1kHz-20MHz frequency range have been investigated. The Cole-Cole plots of HA-based Zn, Sr, Ni doped/Ti-6Al-7Nb capacitors exhibited the semicircles and B(S)-G(S) plots exhibited full circles, suggesting that these materials have dielectric polarization due to external effect. The dielectric properties of the synthesized bioceramic materials have been changed by depending on the doping and reaction time of synthesis. Consequently, the obtained capacitance, impedance and dielectric results suggests that Ti-6Al-7Nb / bioceramic / Ti-6Al-7Nb can be used as a biodielectric sensor in biotechnological applications.