News
Members
Publications
Projects
Courses
Openings
Contact us

Projects

Current location:Projects>>Projects

Large-scale high-density TMR sensor array for magnetic field imaging

Release time:2019-11-12
Funded by Shanghai Pujiang Talent Plan (¥200,000)
This project intends to develop high-density, large-scale tunnelling magneto-resistance (TMR) sensor array for magnetic field imaging. The TMR array consists of 180 sensing elements with the distance of 0.5 mm between any pair of TMR sensors adjacent to each other, which enables to acquire an image with high spatial resolution. With a total length of 90mm, the TMR array is capable of imaging a rectangular area as wide as 90mm in a single scan resulting in a fast inspection speed for evaluation of structure with large surface area. The proposed TMR sensor array has high sensitivity to magnetic field in a frequency range from DC to MHz. So it can be used for detection of deep embedded defects in multilayer riveted structures with excitation currents at ultra-low frequencies.  Experimental results show that machined notches under fasteners head at a distance of 8mm from the top surface of a multilayer riveted aluminium structure can be detected. Furthermore, surface micro-notch can be detected from the obtained magnetic field image.    
 
上海浦江人才计划资助(200,000元)
该项目旨在开发用于磁场成像的高密度大规模隧穿磁阻(TMR)传感器阵列。TMR阵列由180个传感器单元组成,每两个相邻的TMR传感器距离0.5 mm,用来获得高空间分辨率图像。TMR阵列总长度为90毫米,可以在单次扫描中对90毫米宽的矩形区域进行成像,从而以较快的检测速度检测具有较大表面积的结构。这种TMR传感器阵列对从DC到MHz的频率范围内的磁场具有很高敏感度,因此在极低频激励电流下,可以检测多层铆接结构中的深埋缺陷。实验结果表明,此传感器阵列可以检测位于铝板表面8mm下的铆钉周围的人工缺陷。 此外,在高频激励电流下,该阵列也可以检测铝板表面缺陷。
 

Picture of the prototype probe
探头原型
 
Inspection of multilayered riveted structure in aircraft
飞机上多层铆接结构的检验

Experimental images of defects
缺陷的实验图片