Ilgaz Fatih, Spetzler Elizaveta, Wiegand Patrick, Faupel Franz, Rieger Robert, McCord Jeffrey, Spetzler Benjamin
Chair for Multicomponent Materials, Department of Materials Science, Faculty of Engineering, Kiel University, 24143, Kiel, Germany.
Nanoscale Magnetic Materials - Magnetic Domains, Department of Materials Science, Faculty of Engineering, Kiel University, 24143, Kiel, Germany.
Sci Rep. 2024 May 14;14(1):11075. doi: 10.1038/s41598-024-59015-5.
Magnetoelastic micro-electromechanical systems (MEMS) are integral elements of sensors, actuators, and other devices utilizing magnetostriction for their functionality. Their sensitivity typically scales with the saturation magnetostriction and inversely with magnetic anisotropy. However, large saturation magnetostriction and small magnetic anisotropy make the magnetoelastic layer highly susceptible to minuscule anisotropic stress. It is inevitably introduced during the release of the mechanical structure during fabrication and severely impairs the device's reproducibility, performance, and yield. To avoid the transfer of residual stress to the magnetic layer, we use a shadow mask deposition technology. It is combined with a free-free magnetoelectric microresonator design to minimize the influence of magnetic inhomogeneity on device performance. Magnetoelectric resonators are experimentally and theoretically analyzed regarding local stress anisotropy, magnetic anisotropy, and the ΔE-effect sensitivity in several resonance modes. The results demonstrate an exceptionally small device-to-device variation of the resonance frequency < 0.2% with large sensitivities comparable with macroscopic ΔE-effect magnetic field sensors. This development marks a promising step towards highly reproducible magnetoelastic devices and the feasibility of large-scale, integrated arrays.
磁弹性微机电系统（MEMS）是利用磁致伸缩实现其功能的传感器、致动器及其他设备的重要组成部分。其灵敏度通常与饱和磁致伸缩成正比，与磁各向异性成反比。然而，大的饱和磁致伸缩和小的磁各向异性使得磁弹性层极易受到微小各向异性应力的影响。这种应力在制造过程中机械结构释放时不可避免地产生，并严重损害器件的可重复性、性能和成品率。为避免残余应力传递到磁性层，我们采用了荫罩沉积技术。该技术与自由-自由磁电微谐振器设计相结合，以最小化磁不均匀性对器件性能的影响。对磁电谐振器在几种谐振模式下的局部应力各向异性、磁各向异性和ΔE效应灵敏度进行了实验和理论分析。结果表明，谐振频率的器件间变化异常小，<0.2%，且灵敏度高，可与宏观ΔE效应磁场传感器相媲美。这一进展标志着朝着高可重复性磁弹性器件以及大规模集成阵列的可行性迈出了有希望的一步。
