A wireless, passive strain sensor based on the harmonic response of magnetically soft materials
A wireless, passive strain sensor based on the harmonic response of magnetically soft materials
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DOI：
10.1088/0964-1726/17/2/025015
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发表时间：
2008-04-01
影响因子：
4.1
通讯作者：
Ong, Keat Ghee
中科院分区：
文献类型：
--
作者：
Tan, Ee Lim;Pereles, Brandon D.;Ong, Keat Ghee
描述了一种基于软磁材料高阶谐波信号位移的无线无源应变传感器。应变传感器由软磁元件组成，放置在永磁元件上方并由可变形层隔开。当压力施加在应变传感器上时，可变形层的尺寸发生变化，从而改变了软磁元件和永磁元件之间的间隔距离。这反过来又改变了软磁元件的高阶谐波场，从而可以远程测量应力和应变。在当前的研究中，具有独特材料特性的三种不同类型的可变形层被分别纳入传感器中。外力逐渐施加在每个传感器上，并测量谐波信号的变化。传感器的磁谐波谱的变化与机械变化线性相关。应变传感器具有良好的稳定性、线性度和重复性。这种无源无线传感器可用于长期检测物体内部（例如混凝土结构或人体内部）的机械载荷。
A wireless, passive strain sensor based on the shift of higher-order harmonic signals of a magnetically soft material is described. The strain sensor consisted of a magnetically soft element, placed over a permanent magnetic element and separated by a deformable layer. As compressive forces were exerted on the strain sensor, the dimension of the deformable layer varied, changing the separation distance between the soft and permanent magnetic elements. This in turn altered the higher-order harmonic field of the magnetically soft element, allowing remote measurement of stress and strain. In the current study, three different types of deformable layers with distinctive material properties were separately incorporated into the sensor. External forces were gradually applied on each sensor and the variations in harmonic signals were measured. The shifts in the magnetic harmonic spectrum of the sensors were linearly correlated with the mechanical alteration. Good stability, linearity and repeatability of the strain sensor were also demonstrated. This passive and wireless sensor is useful for long-term detection of mechanical loading from within an object such as inside a concrete structure or a human body.