Author:

Publisher:

Published: 2016

Total Pages: 93

ISBN-13:

The electronic analyses of the biological systems using bio potential electrodes have certainly helped the advancement of the human physiological studies. The efficient bio potential electrodes of electronic analysis system can significantly reduce the diagnosis time of malfunctioning human organs such as Brain, Heart etc. Ample amount of research has already been carried out worldwide to optimize recording & exciting bio electrodes. This thesis investigates the powder characterization to develop sintered Silver- Silver Chloride hybrid bio potential electrode for the use of Electroencephalographs (EEG), Electrocardiographs (ECG), Electromyographs (EMG) etc. When it comes to the development of bio potential electrodes the Silver (Ag) & Silver chloride (AgCl) are the first choice of researchers due to the unique materials properties such as very high conductivity, negligible polarization, stable operation (Impedance values) & very small background noise. The experiments conducted in this thesis utilized the powder mixture of Ag & AgCl. Even though the Ag & AgCl have very dissimilar material properties such as melting point, oxidation temperature but successful sintering is possible under the precisely controlled high vacuum conditions. In the experiments, the Ag & AgCl mixture was sintered at two different temperatures (380°C & 430°C) and three sintering dwell times (1, 2 & 3 hr) in high vacuum conditions in a specially designed Alumina (Al2O3) die. The phase analysis of the sintered samples was performed using advanced X-Ray diffraction (XRD) & Energy dissipative X-Rays (EDX) techniques. MATLAB script was used to analyze the images of the sintered samples to measure porosity levels. The sintered electrode assemblies were impregnated with a highly conductive gel using centrifuge. Impedance analysis was done on dry & gel impregnated electrode assemblies. The reduction in impedance & background noise was observed in the gel impregnated electrodes assemblies. Experimental results clearly depicted that the ingenious loose powder sintering of Ag-AgCl powders produces high surfaced area electrodes (highly porous & sintered interconnected Ag, AgCl structure) facilitates the gel impregnation (Hybrid Electrodes). The Hybrid electrodes have superior performance in term of impedance & background noise as compared to the reported Titanium (Ti) & commercially available EEG electrodes.