Reducing Impedance Fluctuation by Electrode Structure for Electrochemical Impedance Spectroscopy

In this paper, we investigated the electrode structure of the electrical bio-sensor to reduce impedance measurement fluctuation. Five pairs of the same electrodes were formed on the PCB substrate, and a fluidic channel was constructed with a double-sided tape and polycarbonate cover so that all the electrodes had the same reagent distribution. In order to find an electrode structure with little change in impedance, the structure of the electrode pairs arranged on the PCB substrate was divided into five types, one to five layers. The electrodes arranged on the PCB substrate are made the same size and the spacing between the electrode pairs is the same. As a result of an experiment in which physiological saline was injected into an electrode chip made of five electrode structures, it was confirmed that the change in the impedance between the electrodes was small as the number of electrode layers was increased.