Microelectrodes: When sensing has nonsense. A sensitivity analysis using finite element modelling

This work presents an electrical analysis of tetrapolar measurements oriented to establish major sensitivity zones in a sensor array for maximizing impedance detection. The study of the sensor was focused on maximizing impedimetric biomass detection to make a stratified analysis of the sample in Electrical Impedance Spectroscopy (EIS). Finite Element Method (FEM) modelling was used to examine the behaviour of a Wenner-Alpha sensor array of 8 steps. An AC/DC quasi-static current mode was used for the computational model. The sensor was simulated for every step in sensitivity and impedance measurements and also fabricated and contrasted with experimental data. Negative sensitivity zones which are critical for impedance or electrochemical detection have been detected and delimited to establish proper detection during microelectrode sensing conditions. This simplified model is a useful and valid tool for understanding the sensitivity spectrum map of an EIS sensor.