Analysis of the effect of low dye concentration for electrical system applications of reactive red 45 dye loaded hydrogels

Abstract

Structural, optical and dielectric properties determining the conduction mechanism were investigated using appropriate measurement techniques to determine the suitability of low-concentrations (LC) (1000 μL, 500 μL, 250 μL and 125 μL) reactive red 45 (RR-45) dye loaded hydrogels for electrical circuit applications. The UV spectra of the all samples displayed a fluctuating behaviour depending on the concentration. It was found that the dielectric plane plots for all the samples are compatible with the Cole-Cole relaxation model and correspond to an equivalent electrical circuit (RC) representing with the impedance circuit in the Smith Chart. It was concluded that RR-45 dye loaded hydrogels could be a suitable material for electrodes used in electroencephalography and electrocardiography systems due to the decrease of the real part of complex dielectric constant and impedance values with increasing frequency. The s-parameter for the samples, which determines the conductivity mechanism, was calculated separately for different regions.