Impedance-spectroscopy-supported microchannel flow rate sensor

We show the evaluation of electrical parameters of liquids inside a Polydimethylsiloxane (PDMS) microchannel. We utilize electrochemical impedance spectroscopy (EIS), a suitable equivalent circuit diagram, describing the electrical parameters of the liquid filled channel and parameter fitting to gain access to said parameters. The influence of the volume flow and conductivity of the liquid on the impedance spectrum will be shown in the corresponding Bode- and Nyquist plots, thus leading to an alteration of the fitting parameters in the equivalent circuit. The evaluation of this parameters, for both conductivity and flow rate simultaneously, will enable the adjustment for the influence of different conductivity liquids on the equivalent circuit parameters for flow rate measurements.