• Title/Summary/Keyword: trilayer

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Single Magnetic Bead Detection in a Microfluidic Chip Using Planar Hall Effect Sensor

  • Kim, Hyuntai;Reddy, Venu;Kim, Kun Woo;Jeong, Ilgyo;Hu, Xing Hao;Kim, CheolGi
    • Journal of Magnetics
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    • v.19 no.1
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    • pp.10-14
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    • 2014

  • In this study, we fabricate an integrated microfluidic chip with a planar Hall effect (PHE) sensor for single magnetic bead detection. The PHE sensor was constructed with a junction size of $10{\mu}m{\times}10{\mu}m$ using a trilayer structure of Ta(3 nm)/NiFe(10 nm)/Cu(1.2 nm)/IrMn(10 nm)/Ta(3 nm). The sensitivity of the PHE sensor was 19.86 ${\mu}V/Oe$. A diameter of 8.18 ${\mu}m$ magnetic beads was used, of which the saturation magnetization was ~2.1 emu/g. The magnetic susceptibility ${\chi}$ of these magnetic beads was calculated to be ~0.14. The diluted magnetic beads solution was introduced to the microfluidic channel attributing a single bead flow and simultaneously the PHE sensor voltage was measured to be 0.35 ${\mu}V$. The integrated microchip was able to detect a magnetic moment of $1.98{\times}10^{-10}$ emu.

  • https://doi.org/10.4283/JMAG.2014.19.1.010 인용 PDF KSCI