Computational Modelling of CNT-Embedded PVDF Nanofibre Mats for Capacitive Humidity Sensing: A MATLAB Implementation

The current paper proposes a MATLAB-based comprehensive computational model for the behaviour of MWCNT/PVDF nanofibre mats used as capacitive humidity sensors. It comprises the application of the Maxwell-Garnett effective medium theory to calculate the dielectric constant of the nanofibre composite, an empirical expression based on the Guggenheim-Anderson-de Boer (GAB) sorption isotherm for the moisture adsorption properties, the Lichtenecker logarithmic law to account for the multi-phase nature of the dielectric response, and Fick's diffusion law for the dynamic aspect of the response. Physical parameters of the model have been extracted from experimental measurements conducted earlier. The model output has been compared to the experimental results reported in a prior work (Hussain et al., 2021) with good correlation at R² > 0.98 between the capacitance-humidity function. The MATLAB code implementing the model has been attached and described, thus allowing users to conduct parametric analysis of various aspects of the problem before the experimental realization, such as varying the CNT content, porosity of the mat, electrodes dimensions, and even CNT functionalization with hydrophilic chemical moieties, which theoretically increases the sensitivity up to 40%.