Revisiting Impedance Spectroscopy: A Didactic Virtual Instrument for Modeling and Analysing Nanomaterials in Gas Sensors

Impedance Spectroscopy (IS) is a valuable technique for characterizing sensing materials in the frequency domain. However, interpreting IS data and linking them to equivalent circuit models with combined effects can be challenging for beginners in the technique. To address this issue, this work revisits the fundamentals of IS and presents a didactic Virtual Instrument (VI) designed to support students and researchers through intuitive simulation and analysis tools. While similar features exist in well-established research software, our VI takes an educational approach by allowing real-time manipulation of model parameters and immediate visualization of their impact on impedance spectra. The software also performs model fitting to experimental data, promoting the development of critical analysis skills. The tool was initially applied with undergraduate research students, demonstrating strong potential for educational use. As a proof of concept, humidity-sensitive MWCNT-based gas sensors were characterized, and fitting results highlighted the most responsive electrical parameters. This approach offers a practical and accessible way to teach IS principles and electrical analysis of materials.