Micromagnetic Simulations of Concentration Detection Capability of Large-Area and Low-Aspect-Ratio GMR Sensors in Biomedical Diagnostics

Since the discovery of giant magnetoresistance (GMR), it has found many applications in sensors. One of these key areas is for biomedical sensing. GMR biosensors with large-area and low-aspect-ratio were demonstrated experimentally with ultrahigh sensitivity, followed by a relatively simplified theoretical explanation. This study presents a systematic micromagnetic simulation analysis of large-area and low-aspect-ratio GMR sensors, with a particular focus on two key regimes: the linear portion before saturation by the magnetic nanoparticle (MNP) interaction with the sensor and the flattening out due to sensor saturation. This study presents a simulation-based analysis of large-area and low-aspect-ratio GMR sensors using micromagnetic simulations for biomedical diagnostic applications. We investigate various MNP types and sizes. Through systematic simulations, we compare sensitivity to concentration and highlight the influence of MNP characteristics and concentration on the large-area GMR sensor’s performance. This study not only furthers the understanding of large-area and low-aspect-ratio GMR sensor behavior but also paves the way for future targeted experimental research and development in this promising field.