Numerical Study on Mass Sensitivity of Magnetoelastic Biosensors with Concentrated Mass Load under Different Resonance Modes

Abstract

Magnetoelastic biosensors are an important type of resonant mode based mass-sensing device, for which mass sensitivity is a critical parameter to evaluate their performance. In this work, the effect of concentrated mass position on mass sensitivity (Sm) of a magnetoelastic sensor under different resonance modes was theoretically studied. The effect of magnitude of loading mass on mass sensitivity for the first resonance mode was also studied. The results indicated that mass sensitivity as the function of loading position for all resonance modes was consistent with the law of functionSm=A cos2t. By comparing the mass sensitivity for the sensor attached with concentrated mass and uniform mass, it was found that mass sensitivity was linearly proportional to the sum of the squares of the displacement of each loading point. For the first resonance mode, when the loading position satisfied0≤xc/l<0.3or0.7<xc/l≤1, mass sensitivity decreased with loading mass increasing. The opposite trend was observed when0.3<xc/l<0.5or0.5<xc/l≤0.7. When the concentrated mass was loaded at the nodal point (i.e.,xc/l=0.5), mass sensitivity was always zero no matter how the loading mass changed.