Dissociation–association equilibrium of magnetic particle chains in homogeneous magnetic fields

1986 ◽  
Vol 29 (11) ◽  
pp. 3626
Author(s):  
H. E. Wilhelm
Keyword(s):  
Magnetic Fields ◽  
Magnetic Particle ◽  
Particle Chains ◽  
Association Equilibrium

Strong vortical flows generated by the collective motion of magnetic particle chains rotating in a fluid cell

Lab on a Chip ◽  
2015 ◽  
Vol 15 (1) ◽  
pp. 351-360 ◽  
Author(s):  
Yang Gao ◽  
Jasper Beerens ◽  
Alexander van Reenen ◽  
Martien A. Hulsen ◽  
Arthur M. de Jong ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Magnetic Particle ◽  
Collective Motion ◽  
Vortical Flow ◽  
Rotating Magnetic Fields ◽  
Magnetic Microparticles ◽  
Biochemical Assays ◽  
Magnetic Capture ◽  
Particle Chains ◽  
Fluid Cell

Magnetic microparticles suspended in a microfluidic cell exhibit coherent collective motion when actuated with rotating magnetic fields, creating strong vortical flow and enhancing biochemical assays with magnetic capture particles.

scholarly journals Optical Imaging of Magnetic Particle Cluster Oscillation and Rotation in Glycerol

2021 ◽  
Vol 7 (5) ◽  
pp. 82
Author(s):  
River Gassen ◽  
Dennis Thompkins ◽  
Austin Routt ◽  
Philippe Jones ◽  
Meghan Smith ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Barium Hexaferrite ◽  
Optical Microscope ◽  
Simplified Model ◽  
Particle Cluster ◽  
Average Deviation ◽  
Cross Sectional

Magnetic particles have been evaluated for their biomedical applications as a drug delivery system to treat asthma and other lung diseases. In this study, ferromagnetic barium hexaferrite (BaFe12O19) and iron oxide (Fe3O4) particles were suspended in water or glycerol, as glycerol can be 1000 times more viscous than water. The particle concentration was 2.50 mg/mL for BaFe12O19 particle clusters and 1.00 mg/mL for Fe3O4 particle clusters. The magnetic particle cluster cross-sectional area ranged from 15 to 1000 μμm2, and the particle cluster diameter ranged from 5 to 45 μμm. The magnetic particle clusters were exposed to oscillating or rotating magnetic fields and imaged with an optical microscope. The oscillation frequency of the applied magnetic fields, which was created by homemade wire spools inserted into an optical microscope, ranged from 10 to 180 Hz. The magnetic field magnitudes varied from 0.25 to 9 mT. The minimum magnetic field required for particle cluster rotation or oscillation in glycerol was experimentally measured at different frequencies. The results are in qualitative agreement with a simplified model for single-domain magnetic particles, with an average deviation from the model of 1.7 ± 1.3. The observed difference may be accounted for by the fact that our simplified model does not include effects on particle cluster motion caused by randomly oriented domains in multi-domain magnetic particle clusters, irregular particle cluster size, or magnetic anisotropy, among other effects.

scholarly journals Consistent energy barrier distributions in magnetic particle chains

2016 ◽  
Vol 486 ◽  
pp. 173-176 ◽  
Author(s):  
O. Laslett ◽  
S. Ruta ◽  
R.W. Chantrell ◽  
J. Barker ◽  
G. Friedman ◽  
...  
Keyword(s):  
Energy Barrier ◽  
Magnetic Particle ◽  
Particle Chains

scholarly journals Formation of Magnetic Particle Chains in Ultra High Magnetic Field

2007 ◽  
Vol 73 (725) ◽  
pp. 305-311
Author(s):  
Hiroyuki KAWAMOTO ◽  
Masatomo TESHIMA ◽  
Hiroyuki TAKAHASHI ◽  
Nobuyuki NAKAYAMA ◽  
Noriyuki HIROTA
Keyword(s):  
Magnetic Field ◽  
High Magnetic Field ◽  
Magnetic Particle ◽  
Particle Chains

scholarly journals Integrated lab-on-chip biosensing systems based on magnetic particle actuation – a comprehensive review

Lab on a Chip ◽  
2014 ◽  
Vol 14 (12) ◽  
pp. 1966-1986 ◽  
Author(s):  
Alexander van Reenen ◽  
Arthur M. de Jong ◽  
Jaap M. J. den Toonder ◽  
Menno W. J. Prins
Keyword(s):  
Magnetic Fields ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Comprehensive Review ◽  
Lab On Chip ◽  
Diagnostic Assays ◽  
On Chip

A review on the use of magnetic particles that are actuated by magnetic fields for integrated lab-on-chip diagnostic assays.

scholarly journals Buckling of paramagnetic chains in soft gels

Soft Matter ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 228-237 ◽  
Author(s):  
Shilin Huang ◽  
Giorgio Pessot ◽  
Peet Cremer ◽  
Rudolf Weeber ◽  
Christian Holm ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Polymer Gels ◽  
Paramagnetic Particle ◽  
Soft Polymer ◽  
Soft Gels ◽  
Particle Chains

Paramagnetic particle chains in soft polymer gels can show pronounced buckling deformation under perpendicular external magnetic fields.

Magnetic particle movement program to calculate particle paths in flow and magnetic fields

2014 ◽  
Vol 351 ◽  
pp. 37-46 ◽  
Author(s):  
Toru Inaba ◽  
Taku Sakazume ◽  
Yoshihiro Yamashita ◽  
Shinya Matsuoka
Keyword(s):  
Magnetic Fields ◽  
Magnetic Particle ◽  
Particle Movement ◽  
Particle Paths

Torque density measurements on vortex fluids produced by symmetry-breaking rational magnetic fields

Soft Matter ◽  
2014 ◽  
Vol 10 (33) ◽  
pp. 6139-6146 ◽  
Author(s):  
Kyle J. Solis ◽  
James E. Martin
Keyword(s):  
Magnetic Fields ◽  
Symmetry Breaking ◽  
Magnetic Particle ◽  
Infinite Family ◽  
Particle Suspensions ◽  
Density Measurements ◽  
Torque Density ◽  
Strong Vorticity

A recently-discovered infinite family of symmetry-breaking rational magnetic fields creates “vortex fluids” that produce strong vorticity along any axis in magnetic particle suspensions.

scholarly journals A Theoretical Analysis of Magnetic Particle Alignment in External Magnetic Fields Affected by Viscosity and Brownian Motion

2021 ◽  
Vol 11 (20) ◽  
pp. 9651
Author(s):  
Andrej Krafcik ◽  
Peter Babinec ◽  
Oliver Strbak ◽  
Ivan Frollo
Keyword(s):  
Magnetic Fields ◽  
Biomedical Applications ◽  
Molecular Mechanisms ◽  
Magnetic Particle ◽  
Fundamental Property ◽  
Oscillatory Behavior ◽  
Magnetic Flux Density ◽  
Inertial Torque ◽  
Particle Alignment ◽  
Viscous Torque

The interaction of an external magnetic field with magnetic objects affects their response and is a fundamental property for many biomedical applications, including magnetic resonance and particle imaging, electromagnetic hyperthermia, and magnetic targeting and separation. Magnetic alignment and relaxation are widely studied in the context of these applications. In this study, we theoretically investigate the alignment dynamics of a rotational magnetic particle as an inverse process to Brownian relaxation. The selected external magnetic flux density ranges from 5μT to 5T. We found that the viscous torque for arbitrary rotating particles with a history term due to the inertia and friction of the surrounding ambient water has a significant effect in strong magnetic fields (range 1–5T). In this range, oscillatory behavior due to the inertial torque of the particle also occurs, and the stochastic Brownian torque diminishes. In contrast, for weak fields (range 5–50μT), the history term of the viscous torque and the inertial torque can be neglected, and the stochastic Brownian torque induced by random collisions of the surrounding fluid molecules becomes dominant. These results contribute to a better understanding of the molecular mechanisms of magnetic particle alignment in external magnetic fields and have important implications in a variety of biomedical applications.

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