Microfluidic propulsion by the metachronal beating of magnetic artificial cilia: a numerical analysis

AbstractIn this work we study the effect of metachronal waves on the flow created by magnetically driven plate-like artificial cilia in microchannels using numerical simulations. The simulations are performed using a coupled magneto-mechanical solid–fluid computational model that captures the physical interactions between the fluid flow, ciliary deformation and applied magnetic field. When a rotating magnetic field is applied to super-paramagnetic artificial cilia, they mimic the asymmetric motion of natural cilia, consisting of an effective and recovery stroke. When a phase difference is prescribed between neighbouring cilia, metachronal waves develop. Due to the discrete nature of the cilia, the metachronal waves change direction when the phase difference becomes sufficiently large, resulting in antiplectic as well as symplectic metachrony. We show that the fluid flow created by the artificial cilia is significantly enhanced in the presence of metachronal waves and that the fluid flow becomes unidirectional. Antiplectic metachrony is observed to lead to a considerable enhancement in flow compared to symplectic metachrony, when the cilia spacing is small. Obstruction of flow in the direction of the effective stroke for the case of symplectic metachrony was found to be the key mechanism that governs this effect.

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Swirling Flow of Magnetic Fluid in Multi-Pole Rotating Magnetic Field

Volume 2: Symposia, Parts A, B, and C ◽

10.1115/fedsm2003-45040 ◽

2003 ◽

Author(s):

Kenichi Kamioka ◽

Ryuichiro Yamane

Keyword(s):

Magnetic Field ◽

Fluid Flow ◽

Circular Cylinder ◽

Phase Velocity ◽

Magnetic Fluid ◽

Swirling Flow ◽

Peak Velocity ◽

Rotating Magnetic Field ◽

Outer Periphery ◽

The Magnetic Field

The experiments are conducted on the magnetic fluid flow induced by the multi-pole rotating magnetic field in a circular cylinder. The numbers of poles are two, four, six, eight and twelve. The applied electric current and frequency are 2∼6 A and 20∼60 Hz, respectively. The peak velocity of the flow increases with the increase in the strength and the phase velocity of the magnetic field. As the increase in the number of poles, the flow shifts to the outer periphery.

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Effect of Rotating Magnetic Field on Microstructure Evolution of Pb-Bi Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.311-313.600 ◽

2011 ◽

Vol 311-313 ◽

pp. 600-608

Author(s):

Zhao Chen ◽

Xiao Li Wen ◽

Chang Le Chen

Keyword(s):

Magnetic Field ◽

Fluid Flow ◽

Microstructure Evolution ◽

Solidification Process ◽

Nucleation And Growth ◽

Primary Phase ◽

Rotating Magnetic Field ◽

Growth Behaviour ◽

Solidification Behaviour ◽

40 Hz

Solidification behaviour of Pb-Bi alloys under rotating magnetic field (RMF) was investigated experimentally to understand the effect of the frequency of RMF on the nucleation and growth behaviour. It was found that, as the increase of the rotating frequency, the grains are fragmented and refined gradually until a transition from columnar to equiaxed microstructures happens at a rotating frequency of 40 Hz. Moreover, the Bi concentration of the primary phase decreases and macrosegregation is eliminated effectively with RMF. These are due to the effect of RMF on the nucleation, growth and fluid flow in the solidification process.

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Frequency effects of a rotating magnetic field on fluid flow in vertical cylinders

10.1117/12.277729 ◽

1997 ◽

Cited By ~ 9

Author(s):

Konstantin Mazuruk ◽

Narayanan Ramachandran ◽

Martin P. Volz ◽

Donald C. Gillies

Keyword(s):

Magnetic Field ◽

Fluid Flow ◽

Rotating Magnetic Field ◽

Frequency Effects ◽

Vertical Cylinders

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FLEXIBLE FERROMAGNETIC FILAMENTS AS ARTIFICIAL CILIA

International Journal of Modern Physics B ◽

10.1142/s0217979211058420 ◽

2011 ◽

Vol 25 (07) ◽

pp. 935-941 ◽

Cited By ~ 4

Author(s):

A. CĒBERS ◽

R. LIVANOVIČS

Keyword(s):

Magnetic Field ◽

Numerical Algorithm ◽

Rotating Magnetic Field ◽

Artificial Cilia ◽

Fixed End ◽

Rotating Field

The model of an artificial cilia as a flexible ferromagnetic filament in a rotating magnetic field is proposed. Numerical algorithm for the simulation of its behavior is developed and the characteristic shapes of the filament with one fixed end under the action of a rotating field are found. It is concluded that ferromagnetic filaments may be used as mixers in microfluidics.

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Fluid flow and microstructure formation in a rotating magnetic field during the directional solidification process

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2009.10.194 ◽

2010 ◽

Vol 491 (1-2) ◽

pp. 395-401 ◽

Cited By ~ 18

Author(s):

Zhao Chen ◽

XiaoLi Wen ◽

ChangLe Chen

Keyword(s):

Magnetic Field ◽

Fluid Flow ◽

Directional Solidification ◽

Solidification Process ◽

Rotating Magnetic Field ◽

Microstructure Formation ◽

Directional Solidification Process

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Self-assembled artificial cilia

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0906819106 ◽

2009 ◽

Vol 107 (5) ◽

pp. 1844-1847 ◽

Cited By ~ 154

Author(s):

Mojca Vilfan ◽

Anton Potočnik ◽

Blaž Kavčič ◽

Natan Osterman ◽

Igor Poberaj ◽

...

Keyword(s):

Magnetic Field ◽

Numerical Simulation ◽

Reynolds Number ◽

Fluid Flow ◽

External Magnetic Field ◽

Low Reynolds Number ◽

Microfluidic Devices ◽

Superparamagnetic Particles ◽

Artificial Cilia ◽

Biomimetic Cilia

Due to their small dimensions, microfluidic devices operate in the low Reynolds number regime. In this case, the hydrodynamics is governed by the viscosity rather than inertia and special elements have to be introduced into the system for mixing and pumping of fluids. Here we report on the realization of an effective pumping device that mimics a ciliated surface and imitates its motion to generate fluid flow. The artificial biomimetic cilia are constructed as long chains of spherical superparamagnetic particles, which self-assemble in an external magnetic field. Magnetic field is also used to actuate the cilia in a simple nonreciprocal manner, resulting in a fluid flow. We prove the concept by measuring the velocity of a cilia-pumped fluid as a function of height above the ciliated surface and investigate the influence of the beating asymmetry on the pumping performance. A numerical simulation was carried out that successfully reproduced the experimentally obtained data.

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On fluid flow induced by a rotating magnetic field

Journal of Fluid Mechanics ◽

10.1017/s0022112065000940 ◽

1965 ◽

Vol 22 (3) ◽

pp. 521-528 ◽

Cited By ~ 66

Author(s):

H. K. Moffatt

Keyword(s):

Magnetic Field ◽

Fluid Flow ◽

Transverse Magnetic ◽

Rotating Magnetic Field ◽

Cylindrical Container ◽

General Shape ◽

Electrically Conducting ◽

Axis Parallel ◽

Induced Currents ◽

The Stability

The interior of an insulating cylindrical container is supposed filled with an incompressible, electrically conducting, viscous fluid. An externally applied magnetic field is caused to rotate uniformly about an axis parallel to the cylinder generators (by applying two alternating components out of phase at right angles). Induced currents in the fluid give rise to a Lorentz force which drives a velocity field, which in general may have a steady and a fluctuating component. The particular case of a circular cylindrical container in a transverse magnetic field is studied in detail. Under certain reasonable assumptions, the resulting flow is shown to have only the steady component, and the distribution of this component is determined. Some conjectures are offered about the stability of this flow and about the corresponding flows in cavities of general shape.

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