  Here, we proposed to test the limits of the bounded diffusion impedance model
by using electrochemical impedance spectroscopy (EIS) measurements in a
microfluidic device architecture bearing a set of microelectrodes integrated in
microchannel. This EIS Nyquist plot behaviour was currently modelled with the
Randles equivalent circuit. In this work, one of the main advantages for using
PyEIS (a Python-based Electrochemical Impedance Spectroscopy) software is being
able to modify and correct the models with a simple implementation in the
source code freely accessible on the website of the author Kristian B. Knudsen.
The obtained results after implementing the diffusion-convective equation in
the PyEIS code permits to adapt each function to be able to plot, simulate and
fit a specific modified Randles for channel-electrode. The modified Randles was
used for preliminary tests for optimization of the parameters of flow in the
microfluidic channel by comparing the diffusion layer thickness as a function
with the volumetric flow.
