Velocity Measurement of Particles Flowing in a Microfluidic Chip Using Shah Convolution Fourier Transform Detection

Kwok, Yien Chian; Jeffery, Nicholas T.; Manz, Andreas

doi:10.1021/ac0013047

Cited by 35 publications

(41 citation statements)

References 19 publications

(28 reference statements)

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“…From the velocity profile, the velocity decrease at the center of the cross section in Fig. 6 is considered to be caused by (5). To reduce the effect of (5), improvements are required, such as designing a larger reserver tank.…”

Section: Preliminary Experiments In Straight Microchannelmentioning

confidence: 99%

“…Several methods have been proposed for measuring EOF. For example, one-dimensional velocity can be obtained by visualizing the liquid flow using fluorescent dyes (1) - (3) and tracer particles (4), (5) . For pressure driven flows, effective tools for measuring two-or three-dimensional velocity fields are micron-resolution particle image velocimetry (microPIV) and micron-resolution particle tracking velocimetry (microPTV) (6) , where the velocities of the tracer particles are assumed to equal those of the continuous liquid due to the small diameter.…”

Section: Introductionmentioning

confidence: 99%

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Measurements of Electric Field and Electrokinetic Phenomena Using Two Kinds of Tracer Particles with Different Mobilities

Shintaku

Azuma

2009

JFST

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In this study, we propose a novel technique to measure electric fields and electrokinetic phenomena in microchannels using two kinds of tracer particles with different electrophoretic mobilities. In the present technique, electric fields, whose precise measurement is quite difficult, is obtained from the velocity differences between two kinds of tracer particles. The principle of electric field measurement is based on the flow visualization and the mathematical analysis of the flow fields of different particles. Each tracer particle with different mobilities due to surface charge densities is mixed in a buffer solution to analyze the flow by particle image velocimetry (PIV). Experimental demonstrations are successfully conducted both in straight and T-shaped microchannels with rectangular cross sections. The experimental results of the electric field are compared with the roughly estimated values based on the numerical analysis of the Laplace equation. The comparison indicates the applicability of the proposed technique because they are in reasonable agreement. Moreover, the detailed electrokinetic phenomena, e.g., the electrophoresis and electro osmosis flow, are successfully investigated using the electric field obtained here. These results lead us to conclude that the proposed method can be used as a practical tool to access the details of electrokinetic phenomena in microchannels.

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Section: Preliminary Experiments In Straight Microchannelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Measurements of Electric Field and Electrokinetic Phenomena Using Two Kinds of Tracer Particles with Different Mobilities

Shintaku

Azuma

2009

JFST

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“…hot-embossing [11], injection, laser ablation [12,13], photolithography with moulding and milling. Another advantage is also a wide range of available polymers such as: poly(carbonate) PC, poly(methyl methacrylate) PMMA [14,15,16,17,18,19], poly(dimethylsiloxane) PDMS [20,21,22]. Polymers used must be appropriately selected, for example due to the mechanical properties and possible way of treatment.…”

Section: Introductionmentioning

confidence: 99%

Lab-on-a-Chip Microdevice with Contactless Conductivity Detector

Blaszczyk¹,

Chudy²,

Brzózka³

et al. 2013

Metrology and Measurement Systems

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This paper describes a new contactless conductivity detector, whose electrodes are constructed of microchannels filled with solution of KCl -called pseudoelectrodes. The lab-on-a-chip microdevice was fabricated in poly(dimethylsiloxane) PDMS, using a moulding technique. The mould was made from a dry negative photoresist with a thickness of 50 μm. During the tests, the dimension and arrangement of pseudoelectrodes` microchannels were evaluated. The analyte was pumped into the microchannel using a syringe pump with a flow rate of 50 μL/min. Reproducible changes of the signal were obtained.

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“…The PIV experiments conducted in a microfluidic chip were demonstrated by Santiago et al 27,28 to implement a micro-PIV set up and obtain spatially resolved velocity measurements in pressure flow and electrokinetic flow devices. Kwok et al 29 used Shah Convolution Fourier Transform Detection to estimate velocities of a single-component particle.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous measurements of the flow velocities in a microchannel by wide/evanescent field illuminations with particle/single molecules

et al. 2005

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A laser-induced fluorescence imaging method was developed to simultaneously measure flow velocities in the middle and near wall of a channel with particles or single molecules, by selectively switching from the wide field excitation mode to the evanescent wave excitation mode. Fluorescent microbeads with a diameter of 175 nm were used to calibrate the system, and the collisions of microbeads with channel walls were directly observed. The 175 nm microbeads velocities in the main flow and at 275 nm from the bottom of the channel were measured. The measured velocities of particles or single molecules in two positions in a microchannel were consistent with the calculated value based on Poiseuille flow theory when the diameter of a microbead was considered. The errors caused by Brownian diffusion in our measurement were negligible compared to the flow velocity. Single lDNA molecules were then used as a flowing tracer to measure the velocities. The velocity can be obtained at a distance of 309.0 ¡ 82.6 nm away from bottom surface of the channel. The technique may be potentially useful for studying molecular transportation both in the center and at the bottom of the channel, and interactions between molecules and microchannel surfaces. It is especially important that the technique can be permitted to measure both velocities in the same experiment to eliminate possible experimental inconsistencies.

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Velocity Measurement of Particles Flowing in a Microfluidic Chip Using Shah Convolution Fourier Transform Detection

Cited by 35 publications

References 19 publications

Measurements of Electric Field and Electrokinetic Phenomena Using Two Kinds of Tracer Particles with Different Mobilities

Measurements of Electric Field and Electrokinetic Phenomena Using Two Kinds of Tracer Particles with Different Mobilities

Lab-on-a-Chip Microdevice with Contactless Conductivity Detector

Simultaneous measurements of the flow velocities in a microchannel by wide/evanescent field illuminations with particle/single molecules

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