The impedance spectrum of a liquid, which is relatively easy to determine, is significantly influenced by numerous physical and chemical properties. Using a microchannel fabricated in PDMS and equipped with two electrodes for impedance spectroscopy, the following investigations were carried out: The influence of volume flow rate and conductivity on the impedance spectrum was determined.

From the knowledge of the structure of the microchannel and the physical effects taking place in it, an equivalent circuit could be determined. Using curve fitting, it was possible to determine from the measurement data and the equivalent circuit which physical properties in the microchannel are influenced by the variation of the volume flow and the conductivity. Further research in this area could be used to design a flow sensor based on impedance spectroscopy.