Magnetic Sensor-Based Detection of Picoliter Volumes of Magnetic Nanoparticle Droplets in a Microfluidic Chip

Jeong, Il-Gyo; Eu, Young-Jae; Kim, Kun Woo; Hu, Xinghao; Sinha, Brajalal; Kim, CheolGi

doi:10.4283/jmag.2012.17.4.302

Cited by 12 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the microfluidic system provides systematic positioning of single beads on the PHE sensor. Microfluidic valves, pumps, and mixers can be added to the microfluidic system with the PHE sensor, which can provide an automated and complex analytical device [11].…”

Section: Introductionmentioning

confidence: 99%

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

Kim¹,

Reddy²,

Kim³

et al. 2014

Journal of Magnetics

Self Cite

View full text Add to dashboard Cite

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 µm × 10 µm 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 µV/Oe. A diameter of 8.18 µm magnetic beads was used, of which the saturation magnetization was ~2.1 emu/g. The magnetic susceptibility χ of these magnetic beads was calculated to bẽ 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 µV. The integrated microchip was able to detect a magnetic moment of 1.98 × 10 −10 emu.

show abstract

Section: Introductionmentioning

confidence: 99%

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

Kim¹,

Reddy²,

Kim³

et al. 2014

Journal of Magnetics

Self Cite

View full text Add to dashboard Cite

show abstract

“…The GMR sensor is a proximity sensor, and only local magnetic stray fields from the droplet are detected. Both simulations and experimental results (Pekas et al 2004 ; Jeong et al 2012 ; Lin et al 2013 ) have shown that magnetic stray fields concentrate at two ends of the droplet as reflected by the local maximums and minimums near the rising and falling edges of the measured signals (Fig. 1 c-bottom panel).…”

Section: Resultsmentioning

confidence: 84%

Supervised discriminant analysis for droplet micro-magnetofluidics

Lin

Fomin

Makarov

et al. 2015

Microfluid Nanofluid

View full text Add to dashboard Cite

We apply the technique of supervised discriminant analysis (SDA) for in-flow detection in droplet-based magnetofluidics. Based on the SDA, we successfully discriminate bivariant droplets of different volumes containing different encapsulated magnetic content produced by a GMR-based lab-on-chip platform. We demonstrate that the accuracy of discrimination is superior when the correlation of variables for data training is included to the case when the spatial distribution of variables is considered. Droplets produced with differences in ferrofluid concentration of 2.5 mg/ml and volume of 200 pl have been identified with high accuracy (98 %), indicating the significance of SDA for e.g. the discrimination in magnetic immuno-agglutination assays. Furthermore, the results open the way for the development of a unique magnetofluidic platform for future applications in multiplexed droplet-based barcoding assays and screening.Electronic supplementary materialThe online version of this article (doi:10.1007/s10404-015-1579-z) contains supplementary material, which is available to authorized users.

show abstract

“…The RKKY interaction between two FM layer is known to cause a unidirectional magnetic anisotropy when one of the FM layers is pinned by an AF layer. Thus, the other almost free FM layer can be used as sensing layer for PHE sensors [110,[173][174][175][176][177]. The RKKY interaction can also be used to tune the H ex of the NiFe sensing layer by varying the thickness of a spacer layer or varying the thickness of FM layers.…”

Section: Spin-valvesmentioning

confidence: 99%

Current trends in planar Hall effect sensors: evolution, optimization, and applications

Elzwawy

Pişkin

Akdoğan

et al. 2021

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The advantages of planar Hall effect (PHE) sensors-their thermal stability, very low detection limits, and high sensitivities-have supported a wide range of advanced applications such as nano-Tesla (nT) magnetometers, current sensing, or low magnetic moment detection in lab-on-a-chip devices. In this review we outline the background and implications of these PHE sensors, starting from fundamental physics through their technological evolution over the past few decades. Key parameters affecting the performance of these sensors, including noise from different sources, thermal stability, and magnetoresistance magnitudes are discussed. The progression of sensor geometries and junctions from disk, cross-to-bridge, ring, and ellipse configuration is also reviewed. The logical sequence of these structures from single magnetoresistive layers to bi-, tri-layers, and spin-valves is also covered. Research contributions to the development of these sensors are highlighted with a focus on microfluidics and flexible sensorics. This review serves as a comprehensive resource for scientists who wish to use PHE for fundamental research or to develop new applications and devices. The conclusions from this report will benefit the development, production, and performance evaluation of PHE-based devices and microfluidics, as well as set the stage for future advances.

show abstract

Magnetic Sensor-Based Detection of Picoliter Volumes of Magnetic Nanoparticle Droplets in a Microfluidic Chip

Cited by 12 publications

References 20 publications

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

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

Supervised discriminant analysis for droplet micro-magnetofluidics

Current trends in planar Hall effect sensors: evolution, optimization, and applications

Contact Info

Product

Resources

About