Configurations and control of magnetic fields for manipulating magnetic particles in microfluidic applications: magnet systems and manipulation mechanisms

Cao, Quanliang; Han, Xiaotao; Li, Liang

doi:10.1039/c4lc00367e

Cited by 110 publications

(64 citation statements)

References 134 publications

(152 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this limit there are important connections between our experiments and conventional continuous flow magnetic separation or particle manipulation schemes; see Ref. [59] for examples. And, even though our experiments were performed in the limit where the MMS cores were unsaturated, this is again not a general requirement.…”

Section: Discussionmentioning

confidence: 99%

Fractionation of Magnetic Microspheres in a Microfluidic Spiral: Interplay between Magnetic and Hydrodynamic Forces

2017

View full text Add to dashboard Cite

Magnetic forces and curvature-induced hydrodynamic drag have both been studied and employed in continuous microfluidic particle separation and enrichment schemes. Here we combine the two. We investigate consequences of applying an outwardly directed magnetic force to a dilute suspension of magnetic microspheres circulating in a spiral microfluidic channel. This force is realized with an array of permanent magnets arranged to produce a magnetic field with octupolar symmetry about the spiral axis. At low flow rates particles cluster around an apparent streamline of the flow near the outer wall of the turn. At high flow rates this equilibrium is disrupted by the induced secondary (Dean) flow and a new equilibrium is established near the inner wall of the turn. A model incorporating key forces involved in establishing these equilibria is described, and is used to extract quantitative information about the magnitude of local Dean drag forces from experimental data. Steady-state fractionation of suspensions by particle size under the combined influence of magnetic and hydrodynamic forces is demonstrated. Extensions of this work could lead to new continuous microscale particle sorting and enrichment processes with improved fidelity and specificity.

show abstract

Section: Discussionmentioning

confidence: 99%

Fractionation of Magnetic Microspheres in a Microfluidic Spiral: Interplay between Magnetic and Hydrodynamic Forces

2017

View full text Add to dashboard Cite

show abstract

“…Compared to these contactless methods, magnetic trapping of particles has several advantages such as low cost, heating free (except for electromagnets), and near independence of the suspending medium properties (e.g., ionic concentration and pH value). [17][18][19] Magnetic trapping relies on the magnetophoretic motion of particles induced in a nonuniform magnetic field, [20][21][22] which has been reported for both magnetic (including a) Author to whom correspondence should be addressed. Electronic mail: xcxuan@clemson.edu.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet

Zhou

Kumar

et al. 2015

Biomicrofluidics

View full text Add to dashboard Cite

Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles.

show abstract

“…Moreover, they have potential of integrating and automating biochemical processes into a palmtopsized chip (Cao et al, 2014). Therefore, the magnetic-based assays on microfluidic chips might overcome the drawbacks of traditional off-chip methods.…”

Section: Introductionmentioning

confidence: 99%

Combination of dynamic magnetophoretic separation and stationary magnetic trap for highly sensitive and selective detection of Salmonella typhimurium in complex matrix

Guo

Tang

Hong

et al. 2015

Biosensors and Bioelectronics

View full text Add to dashboard Cite

Configurations and control of magnetic fields for manipulating magnetic particles in microfluidic applications: magnet systems and manipulation mechanisms

Cited by 110 publications

References 134 publications

Fractionation of Magnetic Microspheres in a Microfluidic Spiral: Interplay between Magnetic and Hydrodynamic Forces

Fractionation of Magnetic Microspheres in a Microfluidic Spiral: Interplay between Magnetic and Hydrodynamic Forces

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet

Combination of dynamic magnetophoretic separation and stationary magnetic trap for highly sensitive and selective detection of Salmonella typhimurium in complex matrix

Contact Info

Product

Resources

About