Yang Yang, Mishra Harshad, Han Tao, Hage-Ali Sami, Hehn Michel, Elmazria Omar
IEEE Trans Ultrason Ferroelectr Freq Control. 2021 Jul;68(7):2566-2575. doi: 10.1109/TUFFC.2021.3069382. Epub 2021 Jun 29.
Surface acoustic wave (SAW) sensors with ferromagnetic materials are used to measure magnetic fields or electric currents. The magnetic field sensitivities of SAW magnetic field sensors are essentially influenced by various factors. The sensing mechanism is complex due to the multiphysics coupling of the magnetic field, solid mechanics, and electric field. The magnetostriction effect, ∆E effect, and the third-order material constants are taken into consideration. The shape demagnetizing effect is reduced by increasing the length-to-width ratio and length-to-height ratio of a ferromagnetic film on an SAW resonator. The model is verified by experiments and accurately predicts the magnetic field sensitivities of SAW resonant magnetic field sensors. The factors affecting the sensitivities are investigated from the perspective of the sensing mechanism. A grooved sensing surface structure is explored for improved sensitivity. The results are beneficial to design reliable SAW magnetic field sensors with enhanced sensitivity.
带有铁磁材料的表面声波（SAW）传感器用于测量磁场或电流。SAW磁场传感器的磁场灵敏度本质上受多种因素影响。由于磁场、固体力学和电场的多物理场耦合，其传感机制较为复杂。考虑了磁致伸缩效应、∆E效应和三阶材料常数。通过增加SAW谐振器上铁磁薄膜的长宽比和长高比来降低形状退磁效应。该模型通过实验得到验证，并能准确预测SAW谐振磁场传感器的磁场灵敏度。从传感机制的角度研究了影响灵敏度的因素。探索了一种带凹槽的传感表面结构以提高灵敏度。这些结果有助于设计出灵敏度更高的可靠SAW磁场传感器。
