Spetzler B, Bald C, Durdaut P, Reermann J, Kirchhof C, Teplyuk A, Meyners D, Quandt E, Höft M, Schmidt G, Faupel F
Institute of Materials Science, Faculty of Engineering, Kiel University, Kaiserstraße 2, 24143, Kiel, Germany.
Institute of Electrical Engineering and Information Technology, Faculty of Engineering, Kiel University, Kaiserstraße 2, 24143, Kiel, Germany.
Sci Rep. 2021 Mar 5;11(1):5269. doi: 10.1038/s41598-021-84415-2.
Delta-E effect sensors are based on magnetoelectric resonators that detune in a magnetic field due to the delta-E effect of the magnetostrictive material. In recent years, such sensors have shown the potential to detect small amplitude and low-frequency magnetic fields. Yet, they all require external magnetic bias fields for optimal operation, which is highly detrimental to their application. Here, we solve this problem by combining the delta-E effect with exchange biased multilayers and operate the resonator in a low-loss torsion mode. It is comprehensively analyzed experimentally and theoretically using various kinds of models. Due to the exchange bias, no external magnetic bias fields are required, but still low detection limits down to [Formula: see text] at 25 Hz are achieved. The potential of this concept is demonstrated with a new operating scheme that permits simultaneous measurement and localization, which is especially desirable for typical biomedical inverse solution problems. The sensor is localized with a minimum spatial resolution of 1 cm while measuring a low-frequency magnetic test signal that can be well reconstructed. Overall, we demonstrate that this class of magnetic field sensors is a significant step towards first biomedical applications and compact large number sensor arrays.
ΔE效应传感器基于磁电谐振器，由于磁致伸缩材料的ΔE效应，该谐振器在磁场中会失谐。近年来，这类传感器已显示出检测小幅度和低频磁场的潜力。然而，它们都需要外部磁偏置场才能实现最佳运行，这对其应用极为不利。在此，我们通过将ΔE效应与交换偏置多层膜相结合来解决这一问题，并使谐振器在低损耗扭转模式下运行。我们使用各种模型对其进行了全面的实验和理论分析。由于交换偏置，无需外部磁偏置场，但在25Hz时仍能实现低至[公式：见原文]的检测限。通过一种允许同时进行测量和定位的新操作方案展示了这一概念的潜力，这对于典型的生物医学逆解问题尤为可取。在测量可良好重建的低频磁测试信号时，该传感器的定位空间分辨率最小为1cm。总体而言，我们证明这类磁场传感器朝着首次生物医学应用和紧凑的大量传感器阵列迈出了重要一步。
