Implementation of Bounded Diffusion Impedance in a Model Pyeis to Correctly Simulate Flow Gradient on Channel-Electrode in Microfluidics

TL;DR

This paper enhances electrochemical impedance modeling in microfluidics by implementing a bounded diffusion impedance correction in PyEIS, enabling better simulation and optimization of flow-related parameters in microchannel-electrode systems.

Contribution

It introduces a modified Randles circuit with bounded diffusion impedance in PyEIS, improving flow gradient simulation in microfluidic electrochemical systems.

Findings

Successful implementation of the bounded diffusion impedance model in PyEIS

Improved fit of EIS data with the modified Randles circuit

Enhanced ability to optimize flow parameters in microfluidic devices

Abstract

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.