Design and Optimization of Sensor Electrode Geometry for Hormone Sensing by COMSOL Multiphysics Software

In the present day, one of the major issues that is affecting human health and the quality of human life is stress. Sensors are developed with different shapes of electrodes. Electrodes with different shapes possess different surface areas for the accumulation of hormones, so they play a vital role in hormone analysis. This paper presents an analysis of sensing methods like electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. It explores the optimization of the electrode shapes for use in hormone detection using these sensing methods. The designs and analyses are conducted using COMSOL MULTIPHYSICS software. COMSOL is used to design and analyze three electrode geometries: stepped cuboidal, cuboidal, and cylindrical for both the techniques. The electrode sizes used are in the standard range of 2–5 mm. The voltage equivalent of the sensed current is around 1 nV (with measured current ranging between around 10 and 520 pA). This is a very small value and is amplified to the order of about 0.1 V, which is more convenient to measure using a signal conditioning circuit. In cyclic voltammetry and thereby EIS, the range of current values shows a 26.61% and 8.39% improvement in cylindrical electrodes compared to stepped cuboidal and cuboidal electrodes, respectively. This can be justified by its increased surface area for hormone accumulation for comparable volumes of electrodes. These improvements can be applied in applications like cortisol hormone detection.