Computational Fluid Dynamics Modelling of Microfluidic Channel for Dielectrophoretic BioMEMS Application

Low, Wan Shi; Kadri, Nahrizul Adib; Abas, Wan Abu Bakar Wan

doi:10.1155/2014/961301

Cited by 12 publications

(9 citation statements)

References 30 publications

(48 reference statements)

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“…Alternatively, a microchannel reactor (Figure 17) can be used, in which the channel is 1-1000 µm; this has the advantages of having a significantly larger surface to volume ratio (10-30 cm 2 cm −3 ) compared to other PEC reactors (0.7-5 cm 2 cm −3 [46]) and fine flow control using inlet and outlet branches to ensure a uniform flow and, therefore, achieving a near consent residence time [74], there is also improved mass transport and direct photon absorption at the surface of the photoelectrode with minimal photon absorption by the solution [49]. However, these reactors can be difficult to scale up, resulting in non-uniform residence times and, for real water sources, particulates of a set size would have to be filtered to prevent blockages within the microchannels [75].…”

Section: Channel/microchannel Reactormentioning

confidence: 99%

A Review of Photoelectrocatalytic Reactors for Water and Wastewater Treatment

McMichael

Fernández‐Ibáñez

Byrne

2021

Water

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The photoexcitation of suitable semiconducting materials in aqueous environments can lead to the production of reactive oxygen species (ROS). ROS can inactivate microorganisms and degrade a range of chemical compounds. In the case of heterogeneous photocatalysis, semiconducting materials may suffer from fast recombination of electron–hole pairs and require post-treatment to separate the photocatalyst when a suspension system is used. To reduce recombination and improve the rate of degradation, an externally applied electrical bias can be used where the semiconducting material is immobilised onto an electrically conducive support and connected to a counter electrode. These electrochemically assisted photocatalytic systems have been termed “photoelectrocatalytic” (PEC). This review will explain the fundamental mechanism of PECs, photoelectrodes, the different types of PEC reactors reported in the literature, the (photo)electrodes used, the contaminants degraded, the key findings and prospects in the research area.

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Section: Channel/microchannel Reactormentioning

confidence: 99%

A Review of Photoelectrocatalytic Reactors for Water and Wastewater Treatment

McMichael

Fernández‐Ibáñez

Byrne

2021

Water

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“…As the flow was transported through the symmetrically-split-downstream channels, a downward colour sweep which indicated a decrease in the velocity field was observed in the surface plot. Such a condition is caused by the increase of hydraulic resistance within the proposed design and was explained in detail in our previous paper [56]. Interestingly, a study …”

Section: Fluid Flow Parameter and Dynamic Pressure Of Proposed Microcmentioning

confidence: 73%

“…In order to achieve a uniform loading capacity for a given chamber size, a tree-network design from our previous study [56] was implemented into the geometrical design in this DEP stage. It refers to the branched channel geometry in between both MAP and DEP stages.…”

Section: Evaluation With Dep Stagementioning

confidence: 99%

“…This is to help in equalizing the hydraulic resistance within these channels and thereby generating a uniform flow distribution throughout the whole wide chamber of the DEP stage. Such a condition has been defined theoretically in Low et al [56]. To reduce the presence of a zero velocity within channels, a curved corner as discussed in the previous section was employed.…”

Section: Evaluation With Dep Stagementioning

confidence: 99%

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Computational Analysis of Enhanced Circulating Tumour Cell (CTC) Separation in a Microfluidic System with an Integrated Dielectrophoretic-Magnetophorectic (DEP-MAP) Technique

Low

Kadri

2016

Chemosensors

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Abstract:Cell based cancer analysis is an important analytic method to monitor cancer progress on stages by detecting the density of circulating tumour cells (CTCs) in the blood. Among the existing microfluidic techniques, dielectrophoresis (DEP), which is a label-free detection method, is favoured by researchers. However, because of the high conductivity of blood as well as the rare presence of CTCs, high separation efficiency is difficult to achieve in most DEP microdevices. Through this study, we have proposed a strategy to improve the isolation performance, as such by integrating a magnetophoretic (MAP) platform into a DEP device. Several important aspects to be taken into MAP design consideration, such as permanent magnet orientation, magnetic track configuration, fluid flow parameter and separation efficiency, are discussed. The design was examined and validated by numerical simulation using COMSOL Multiphysics v4.4 software (COMSOL Inc., Burlington, MA, USA), mainly presented in three forms: surface plot, line plot, and arrow plot. From these results, we showed that the use of a single permanent magnet coupled with an inbuilt magnetic track of 250 µm significantly strengthens the magnetic field distribution within the proposed MAP stage. Besides, in order to improve dynamic pressure without compromising the uniformity of fluid flow, a wide channel inlet and a tree-like network were employed. When the cell trajectory within a finalized MAP stage is computed with a particle tracing module, a high separation efficiency of red blood cell (RBC) is obtained for blood samples corresponding up to a dilution ratio of 1:7. Moreover, a substantial enhancement of the CTCs' recovery rate was also observed in the simulation when the purposed platform was integrated with a planar DEP microdevice.

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“…However, it depends on the final application of the device and the surface modification process. Computer-based simulations are becoming increasingly important in the design of microfluidic devices, as they can predict the behavior of fluid flow in a typical microfluidic system in a short time, yielding results that are virtually identical with that of hours or days of practice [3][4][5][6]. In this paper, the effect of the position of the inlet and outlet microchannels on the flow profile and the geometry of the recognition chamber for sample pretreatment in an electrochemical biosensor for osteoporosis management were investigated through a preprocessing step, such as a mathematical simulation.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of a multi-inlet microfluidic device for biosensing purposes in osteoporosis management

Khashayar

Okhovat

Adibi

et al. 2019

J Diabetes Metab Disord

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Objectives In this paper, the effect of the position of the inlet and outlet microchannels on the flow profile and the geometry of the recognition chamber for sample pre-treatment in an electrochemical biosensor to be used in osteoporosis management were investigated. Methods All numerical computation presented in this work were performed using COMSOL Multiphysics and Fluent. Simulation was performed for a three-dimensional, incompressible Navier-Stokes flow and so explicit biphasic volume of fluid (VOF) equations were used. Results In the designed microfluidic system, a pressure-driven laminar flow with no-slip boundary condition was responsible for fluid actuation through microchannels in a reproducible approach. Based on the simulation results, the number of outlets was increased and the angel through which the inlets and outlets were attached to the microchamber was changed so that the dead volume would be eliminated and the fluid flow trajectory, the velocity field and pressure were evenly distributed across the chamber. The Re number in the inlets was equal to 4.41, suggesting a laminar flow at this site. Conclusion The simulation results along with the fact that the design change was tested using laser ablated tape and a color dye at different steps provided the researchers with the opportunity to study the changes in a fast and accurate but cheap method. The absence of backflow helps with the cross-talk concern in the channels and the lack of bubbles and complete coverage of the chamber helps with a better surface modification and thus better sensing performance.

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Computational Fluid Dynamics Modelling of Microfluidic Channel for Dielectrophoretic BioMEMS Application

Cited by 12 publications

References 30 publications

A Review of Photoelectrocatalytic Reactors for Water and Wastewater Treatment

A Review of Photoelectrocatalytic Reactors for Water and Wastewater Treatment

Computational Analysis of Enhanced Circulating Tumour Cell (CTC) Separation in a Microfluidic System with an Integrated Dielectrophoretic-Magnetophorectic (DEP-MAP) Technique

Numerical simulation of a multi-inlet microfluidic device for biosensing purposes in osteoporosis management

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