Tuning magnetofluidic spreading in microchannels

Wang, Zhaomeng; Varma, Vijaykumar B.; Wang, Zhi Ping; Ramanujan, R.V.

doi:10.1088/0960-1317/25/12/124001

Cited by 15 publications

(17 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1), using two immiscible phases: oil as the continuous phase (CP) and water-based ferrofluid (please see Table 1 for ferrofluid properties) or water based dye solution as the dispersed phase (DP). Uniform magnetic fields were applied perpendicular to droplet flow, and high-speed imaging was performed using our micro-magnetofluidic setup6869.…”

Section: Resultsmentioning

confidence: 99%

“…The micromagnetofluidic setup6869 used for our experimental studies (Fig. 1c), consists of (i) microfluidic droplet generation, (ii) uniform magnetic field and (iii) high-speed imaging.…”

Section: Discussionmentioning

confidence: 99%

“…The density ρ and viscosity η are defined using the weighted average interpolation, for a volume fraction of the ferrofluid ( = 1 represents DP) by the following equations6869.…”

Section: Discussionmentioning

confidence: 99%

“…Magnetic Volume Force F m2 . The magnetic volume force, F m2 acts on the total volume of the ferrofluid droplet, it defines the motion of ferrofluid droplets in the microchannel under the influence of a magnetic field H6982. This force depends on the total volume of the ferrofluid droplet.…”

Section: Discussionmentioning

confidence: 99%

“…( b ) Colour dye + magnetite (ferrofluid) composite droplets (100 μm channel height). ( c ) Schematic of micromagnetofluidic setup6869 (i) microfluidic droplet generation along the CP flow in the x-direction, (ii) magnetic field, H along y-direction (iii) high-speed imaging. The high-speed camera is mounted in the z-direction, perpendicular to both the CP flow and magnetic field direction.…”

Section: Figurementioning

confidence: 99%

See 4 more Smart Citations

Droplet Merging on a Lab-on-a-Chip Platform by Uniform Magnetic Fields

Varma

Ray

Wang

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Droplet microfluidics offers a range of Lab-on-a-chip (LoC) applications. However, wireless and programmable manipulation of such droplets is a challenge. We address this challenge by experimental and modelling studies of uniform magnetic field induced merging of ferrofluid based droplets. Control of droplet velocity and merging was achieved through uniform magnetic field and flow rate ratio. Conditions for droplet merging with respect to droplet velocity were studied. Merging and mixing of colour dye + magnetite composite droplets was demonstrated. Our experimental and numerical results are in good agreement. These studies are useful for wireless and programmable droplet merging as well as mixing relevant to biosensing, bioassay, microfluidic-based synthesis, reaction kinetics, and magnetochemistry.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The micromagnetofluidic setup6869 used for our experimental studies (Fig. 1c), consists of (i) microfluidic droplet generation, (ii) uniform magnetic field and (iii) high-speed imaging.…”

Section: Discussionmentioning

confidence: 99%

“…The density ρ and viscosity η are defined using the weighted average interpolation, for a volume fraction of the ferrofluid ( = 1 represents DP) by the following equations6869.…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

See 3 more Smart Citations

Droplet Merging on a Lab-on-a-Chip Platform by Uniform Magnetic Fields

Varma

Ray

Wang

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

Magnetofluidic spreading in circular chambers under a uniform magnetic field

Maleki

Zhang

Kashaninejad

et al. 2020

Microfluid Nanofluid

View full text Add to dashboard Cite

Elucidating the microscale interaction between magnetism and fluid flow is of great importance for designing micro-magnetofluidic gradient generators, micromixers, and particle sorters. Coflowing magnetic and non-magnetic fluids can lead to instability at their interface and subsequent rapid mixing. The mismatch in the magnetisation of the fluids leads to instabilities. The present study systematically investigates the magnetofluidic spreading phenomena of both magnetic nanoparticles and non-magnetic fluorescent dye in consecutive circular chambers. Numerical simulations and experimental investigations were conducted to thoroughly evaluate the physics of magnetofluidic spreading. We show that the presence of the consecutive chambers can enhance magnetofluidic spreading by slowing down the flow and increasing the mass transfer rate transversal to the flow direction. The numerical results reveal that the magnetic force, induced by the magnetic susceptibility gradient, generates cross-sectional secondary flows that steer particles toward both the top and bottom walls. The induced secondary flow also enhances the transport of fluorescent dye, thereby leading to a higher mass transfer rate as compared to pure molecular 2 diffusion. The findings provide further insights into the microscale spreading phenomenon of magnetic and non-magnetic particles in a magnetic field.

show abstract