Design of a rectangular patch antenna-based electrolyte sensor for palmer hyperhidrosis patients

This research proposes a novel non-invasive microwave patch antenna for palmoplantar hyperhidrosis-associated sweat discharge rate analysis. The proposed method consists of a sensor which is a rectangular microstrip patch antenna with a copper patch, embedded in a cellulose paper-based substrate classified as Whatman Filter paper. Paper-based microfluidic technologies have recently emerged as a notable innovation across various domains, including healthcare, environmental surveillance, chemical analysis and so on. In this work 4 types of Whatman Filter paper grades are used as substrates to analyze the antenna parameters for similar electrolyte levels. Among these 4 grades, grade 3 which has 390 µm of thickness, signifies most efficient in sensor design due to high absorbability and porosity. The proposed sensor has a S11 parameter value of -31.02 dB and frequency of resonance of 1.57 GHz, shows remarkable alignment with simulations conducted using COMSOL Multiphysics 6.2. To guarantee the sensor's effectiveness, thorough analyses are performed on the electric field, antenna's efficiency and radiation pattern. The sensor identifies concentrations as low as 0.01 mol/L achieving a maximum sensitivity of 31.02 dB. The proposed sensor offers a straightforward method for sampling and characterizing liquids, demonstrating improved sensitivity and reliable performance through the use of microwave signals.