Increase the sensitivity of magnetoelastic sensors by modifying the sensor geometry

Magnetoelastic sensors have gained a huge interest during the last years. Due to their change on the resonance frequency in response to a mass load, they present the capacity to detect low amounts of different chemical or biological compounds in a precise, cheap, quick and wireless way. In this work, we present a novel approach to increase the sensitivity of that kind of sensors by changing the sensor geometry and by modifying the percentage of coated surface by a mass load. By this new approach, the sensitivity could increases more than a 1000% with respect to the commonly used rectangular shaped magnetoelastic sensors with an uniformly distributed mass load. This work correlates experimental and theoretical results to develop a new model able to quantify the mass attached to the magnetoelastic ribbons. Moreover, the influence of the sample geometry and coating distribution on different magnetic and magnetoelastic parameters such as the delta E effect, the position of the nodal point or the anisotropy field has been studied and significant differences have been observed.