Modeling and Characteristic Study of Thin Film Based Biosensor Based on COMSOL

The model of thin film based biosensor is built based on COMSOL in order to simulate and optimize the electronic characteristic of dipolar electrodes system and tetrapolar electrodes system. Zones of negative sensitivity exist between current carrying electrodes and voltage measuring electrodes while the polarization occurs at the edges of electrodes. By changing the parameters embracing distance between electrodes, thickness of electrodes, and the width of inner electrodes (for tetrapolar electrodes system only), the polarization and zones of negative sensitivity can be receded to some extent, which improves the system’s performance. Tetrapolar electrodes system has less polarization but more negative-sensitivity zones compared to dipolar electrodes system and different setups response differently to these changing parameters.