Miniaturised Four-Electrode Conductivity Probe with PEDOT:PSS Coating

This paper presents a miniaturized four-electrode probe for measuring the conductivity of biological tissues at radio frequencies. The probe was developed to address two common challenges in tissue conductivity measurements at radio frequencies: the limited size of the sample compared to the sensing volume of the probe and the electrode polarization effect. Measurement of the conductivity of the samples can be made by miniaturizing the probe so the sensing volume is smaller the size of the sample. To address the issue of electrode polarization, a PEDOT:PSS coating was applied on the electrodes to reduce the impedance of the electrodes, moving the polarization effect to lower frequencies outside the frequency range of interest. The results demonstrate that this miniaturized probe is a reliable and accurate tool for measuring conductivity of biological tissues at radio frequencies.