Effect of composition on the dielectric properties of hydrogels for biomedical applications

The effect of composition on the dielectric properties of hydrogels for biomedical applications is experimentally investigated. The hydrogels, containing hydroxyethylcellulose (HEC), are characterized by means of the impedance spectroscopy technique. The real and imaginary parts of the electrical impedance of the hydrogels are determined for several concentrations of HEC, and of KCl, dissolved in it, for the frequency range of interest for biomedical applications. The results are compared with those corresponding to depurated water. The equivalent conductivity of the hydrogels is evaluated by performing measurements on samples of different thicknesses. With the limit of a small concentration of salt (⩽6%), the dependence of the electrical conductivity of the hydrogel on the salt concentration is linear.