Semianalytical mass transfer impedance model in microfluidic electrochemical chips

Abstract

In this paper we report a semianalytical model of the mass transfer impedance in microfluidic electrochemical chips (MEC). It is based on the molar advection diffusion equation in a microfluidic channel with a Poiseuille flow and an electrochemical reaction at the interface of deposited electrodes. Using the Fourier-Laplace integral transforms and the quadrupole formalism, a solution to these equations is found and the three dimensional (3D) transient concentration and current density fields are computed. This solution is validated using MFC operando concentration fields measured by visible spectroscopic imaging technique, and several equivalent electrical circuits are also proposed to model the mass transfer in MEC. This work reports the fastest way to compute the 3D transient mass transfer impedance which can be used in large variety of applications such as MEC based cytometry measurements or fuel cell current density prediction.