巨磁电阻传感器对铁磁流体的动态检测  

Dynamic detection of ferrofluid with giant magnetoresistance sensor

作　　者：石海平[1] 冯洁[1] 陈翔[1] 李福泉[1] 

机构地区：[1]上海交通大学微纳科学技术研究院,上海200240

出　　处：《仪器仪表学报》2011年第5期1033-1037,共5页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(60971039);国家高技术研究发展计划863项目(2007AA04Z310)资助

摘　　要：研究一种集成微流道的巨磁电阻(GMR)传感器对铁磁流体的动态检测。利用SU-8胶和PDMS键合在巨磁电阻传感器上集成微流道。铁磁流体为直径10 nm的Fe3O4悬浮溶液。巨磁电阻传感器通过直接测量铁磁流体流过有效检测区域时磁珠的感应场,实现对铁磁流体的动态检测。为使检测的灵敏度最大,综合考虑了外加磁场对传感器灵敏度和磁珠感应场的影响。实验结果表明巨磁电阻传感器能够检测到铁磁流体的流动,且传感器信号与微流道中铁磁流体的磁珠浓度成正比。A giant magnetoresistance（GMR） sensor with integrated microfludic channel was studied for the dynamic detection of ferrofluid.The microfludic channel is integrated by SU-8 glue and PDMS bonding.The ferrofluid is a 10 nm Fe3O4 suspension.The dynamic detection is carried out by directly measuring the fringe fields generated from superparamagnetic beads when the ferrofluid passes the active sensing area of a GMR sensor.To maximizing the detection sensitivity,the effect of the applied magnetic fields on both the sensor sensitivity and bead fringe fields is taken into account.Experiment results show that GMR sensors can detect the ferrofluid flow,and the sensor signals are proportional to the bead concentration of the ferrofluid in the microfludic channel.

关 键 词：巨磁电阻 磁传感器 铁磁流体 微流体 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]