Wang Sheng-Feng, Chiang Chia-Chin
Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan.
Materials (Basel). 2015 Oct 19;8(10):7074-7083. doi: 10.3390/ma8105361.
In this paper, we provide a novel micro rectangular-shaped long-period fiber grating (MRSLPFG) coated with Fe₃O₄ nanoparticles as the sensing material and packaged in polydimethylsiloxane (PDMS) for magnetic sensing application. The micro rectangular-shaped grating structures are fully dip coated with the magnetic fluid and heated to form a thin solid film. This thin overlay is used as the sensing media to measure the external magnetic flux density parallel to the optical fiber axis. According to our experimental results, the phenomenon of the transmission loss of the MRSLPFG magnetic sensor was increased monotonically when the external applied magnetic flux density increased. As the external applied magnetic flux density was increased from 0 to 91.10 mT, the resonance attenuation dip of the MRSLPFG increased and the average sensitivity achieved during the experiments was 0.129 dB/mT. We infer that the aforementioned experimental results were due to the magnetostrictive effect exerted on the thin layer of Fe₃O₄ nanoparticles, which in turn induced slight longitudinal strains on the micro rectangular-shaped fiber grating structures under different magnetic flux density.
在本文中，我们提供了一种新型的微矩形长周期光纤光栅（MRSLPFG），其涂覆有作为传感材料的四氧化三铁（Fe₃O₄）纳米颗粒，并封装在聚二甲基硅氧烷（PDMS）中用于磁传感应用。微矩形光栅结构完全浸渍涂覆有磁性流体并加热以形成薄固体膜。该薄覆盖层用作传感介质来测量平行于光纤轴的外部磁通密度。根据我们的实验结果，当外部施加的磁通密度增加时，MRSLPFG磁传感器的传输损耗现象单调增加。随着外部施加的磁通密度从0增加到91.10 mT，MRSLPFG的共振衰减凹陷增加，实验期间实现的平均灵敏度为0.129 dB/mT。我们推断上述实验结果是由于施加在四氧化三铁纳米颗粒薄层上的磁致伸缩效应，这反过来又在不同磁通密度下在微矩形光纤光栅结构上引起了轻微的纵向应变。
