Loading...
Search for:
microfluidics
0.006 seconds
Total 320 records
Simulation of a falling droplet in a vertical channel with rectangular obstacles
, Article European Journal of Mechanics, B/Fluids ; Volume 68 , March-April , 2018 , Pages 108-117 ; 09977546 (ISSN) ; Ebrahimi, S ; Moosavi, A ; Shafii, M. B ; Kowsary, F ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Droplet microfluidic systems have attracted a large amount of research due to their numerous applications in biomedical micro-devices and drug discovery/delivery platforms. One of the most important problems in such systems is to investigate deformation, coalescence, and breakup of droplets within the channel. The present study demonstrates numerical simulation of a falling droplet subject to gravitational force in a channel with embedded rectangular obstacles. The lattice Boltzmann method incorporated using He–Chen–Zhang method for two phase flow is employed. Two rectangular obstacles with inverse aspect ratios are introduced to investigate the mechanism of breakup and deformation of the...
Ion-pair extraction-reaction of calcium using Y-shaped microfluidic junctions: An optimized separation approach
, Article Chemical Engineering Journal ; Volume 334 , 2018 , Pages 2603-2615 ; 13858947 (ISSN) ; Karimi Sabet, J ; Amini, Y ; Sharif University of Technology
Elsevier B.V
2018
Abstract
In this research, a continuous microsolvent extraction-reaction was developed for the efficient separation of calcium ion. This study gives a preliminary possible practical application of microfluidic devices in chemical exchange reaction for enrichment of 48Ca stable isotope. For this purpose, in the first stage, the hydrodynamic behavior of two immiscible liquids in a simple Y-shaped microfluidic junction is experimentally investigated, and then ion-pair extraction-reaction of Ca2+ using picric acid as a counter-ion and dicyclohexano-18-crown-6 (DC18C6) as a lipophilic ionophore is studied in this microfluidic and conventional batch method. The impact of main process parameters, including...
A continuous flow microfluidic device based on contactless dielectrophoresis for bioparticles enrichment
, Article Electrophoresis ; Volume 39, Issue 3 , 2018 , Pages 445-455 ; 01730835 (ISSN) ; Mohammadi, A. A ; Kalhor, H. R ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
In recent years, applications of dielectrophoresis-based platforms have been recognized as effective and dependable approach to separate cells and bioparticles, suspended in different carrier fluids, based on particle size and electrical properties. In this study, a microfluidic device was fabricated by an unprecedented electrode pattern, and several experiments were performed to enrich samples including either of yeast, Escherichia coli, or latex particles. A chemical deposition-based method was employed for fabrication of microelectrodes, inducing nonuniform electric field required for dielectrophoresis-based separation. One major advantage of our employed method is low fabrication cost,...
Design and fabrication of a two-phase diamond nanoparticle aided fast PCR device
, Article Analytica Chimica Acta ; Volume 1068 , 2019 , Pages 28-40 ; 00032670 (ISSN) ; Ghazimirsaeed, E ; Shamloo, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Polymerase Chain Reaction (PCR) is an important and prevalent technique in biotechnology because of its crucial role in cloning DNA fragments and diagnostic applications. In the present study, a high-throughput two-phase PCR device is designed and fabricated which utilizes a serpentine microchannel together with a spiral structure. The former is for the droplet-generation and mixing and the latter is for the thermal cycling process. Moreover, the effect of diamond nanoparticles (diamondNP) on the performance of PCR is also investigated while using commercial PCR devices and the fabricated PCR device designed in this study. Using numerical simulation, it is shown that within the simple and...
Revealing electrical stresses acting on the surface of protoplast cells under electric field
, Article European Journal of Mechanics, B/Fluids ; Volume 76 , 2019 , Pages 292-302 ; 09977546 (ISSN) ; Moghimi Zand, M ; Hadi, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
When cells exposed to an electric field, localized changes in the distribution of the electric field will be induced and these changes in turn lead to electrical stresses on cell surface. The electrical stresses play a key role in the cell membrane structural changes which leads to important phenomena like hydrophilic pores formation on the cell membrane resulting in the cell permeability. In this work, protoplast cell interaction with direct current (DC) electric field is investigated. The electrical stresses acted on the cell membrane in the presence of electric field are investigated numerically by a modified finite difference method, fast Immersed Interface Method (IIM). Exact solution...
A numerical model for predicting hepatocytes ureagenesis and its related inborn enzyme deficiencies: case studies
, Article Scientia Iranica ; Volume 26, Issue 1B , 2019 , Pages 408-420 ; 10263098 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Firoozbakhsh, K ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
One important functionality of liver cells is ammonia detoxification and urea production. In this study, a numerical model of the urea cycle in hepatocytes was developed. Navier Stokes and convection equations were employed to study the process of ammonia elimination and urea production using a microfluidic channel. The concentration of urea and ammonia throughout the channel was obtained. Furthermore, the urea cycle was modelled with respect to its four main enzymes. This resulted in twelve rate equations that were solved to determine the concentration of each metabolite participating in the urea cycle. Application of results implied common disorders such as hyperammonemia types I and II...
A numerical model for predicting hepatocytes ureagenesis and its related inborn enzyme deficiencies: Case studies
, Article Scientia Iranica ; Volume 26, Issue 1B , 2019 , Pages 408-420 ; 10263098 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Firoozbakhsh, K ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
One important functionality of liver cells is ammonia detoxification and urea production. In this study, a numerical model of the urea cycle in hepatocytes was developed. Navier Stokes and convection equations were employed to study the process of ammonia elimination and urea production using a microfluidic channel. The concentration of urea and ammonia throughout the channel was obtained. Furthermore, the urea cycle was modelled with respect to its four main enzymes. This resulted in twelve rate equations that were solved to determine the concentration of each metabolite participating in the urea cycle. Application of results implied common disorders such as hyperammonemia types I and II...
Simulation of blood particle separation in a trapezoidal microfluidic device by acoustic force
, Article IEEE Transactions on Electron Devices ; Volume 66, Issue 3 , 2019 , Pages 1495-1503 ; 00189383 (ISSN) ; Yazdan Parast, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Nowadays, the importance of the blood particles separation is undeniable in medical fields and there are different sorts of separation methods accordingly. Acoustic cell separation is chosen in this paper. Also, numerical methods have been used to study the effect of geometrical factors on the separation of the particles before spending time and expenses in a trial and error manner experimentally. We have implemented a plenary finite-element-based simulation of separatingblood particles such as white blood cells and platelets in an acoustic field using standing surface acoustic waves. In this paper, unlike previous works in which the channel is rectangular; the channel is trapezoidal in...
Improving the performance of a photonic PCR system using TiO2 nanoparticles
, Article Journal of Industrial and Engineering Chemistry ; 2020 ; Ghazimirsaeed, E ; Shamloo, A ; Dizani, M ; Sharif University of Technology
Korean Society of Industrial Engineering Chemistry
2020
Abstract
Nucleic acid amplification using polymerase chain reaction (PCR) method has been widely used in different fields such as agricultural science, medicine, pathogen identification, and forensics to name a few. Today, it seems inevitable to have a robust, simple PCR system for diagnostics at the point-of-care (POC) level. Many photonic PCR systems have been proposed in the literature that benefit from plasmonic photothermal heating to achieve the common PCR thermal cycling. However, non-homogeneous temperature distribution is a challenge in some of them. In the present work, to achieve more efficient gene amplification, the effect of adding TiO2 nanoparticles has been investigated in a photonic...
The coupled microfluidic microbial electrochemical cell as a self-powered biohydrogen generator
, Article Journal of Power Sources ; Volume 451 , 2020 ; Mardanpour, M. M ; Yaghmaei, S ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Due to the importance of hydrogen as an effective antioxidant for its applications in therapy, this research reports the fabrication of a coupled microfluidic microbial electrochemical cell (MXC), including microfluidic microbial fuel cells (MFCs) and a microfluidic microbial electrolysis cell (MEC) series in order to perform it as a self-powered biohydrogen generator. Being able to be a platform of implantable medical devices, utilization a non-phatogenic strain of Escherichia coli as the biocatalyst in order to exploit the embodied energy from human blood and excrement and finally the use of cheap and facile materials (<$2 per device) are the exceptional features of the system. The...
Microfluidic-based approaches in targeted cell/particle separation based on physical properties: fundamentals and applications
, Article Small ; Volume 16, Issue 29 , 2020 ; Shamloo, A ; Ahadian, S ; Amirifar, L ; Akbari, J ; Goudie, M. J ; Lee, K ; Ashammakhi, N ; Dokmeci, M. R ; Di Carlo, D ; Khademhosseini, A ; Sharif University of Technology
Wiley-VCH Verlag
2020
Abstract
Cell separation is a key step in many biomedical research areas including biotechnology, cancer research, regenerative medicine, and drug discovery. While conventional cell sorting approaches have led to high-efficiency sorting by exploiting the cell's specific properties, microfluidics has shown great promise in cell separation by exploiting different physical principles and using different properties of the cells. In particular, label-free cell separation techniques are highly recommended to minimize cell damage and avoid costly and labor-intensive steps of labeling molecular signatures of cells. In general, microfluidic-based cell sorting approaches can separate cells using “intrinsic”...
Numerical investigation on mixing intensification of ferrofluid and deionized water inside a microchannel using magnetic actuation generated by embedded microcoils for lab-on-chip systems
, Article Chemical Engineering and Processing - Process Intensification ; Volume 147 , 2020 ; Shafii, M. B ; Ghassemi, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Effective and rapid mixing is crucial for chemical and biological processes. The purpose of the current study is to investigate the effect of steady and varying magnetic field on the mixing of a water-based ferrofluid and two streams of deionized water inside a microchannel for Lab-on-Chip applications. To this end, the nonlinear governing equations, the momentum equation, the continuity equation, the mass transport equation and the Maxwell-Ampere equations are numerically solved. A commercial code based on the finite-element method is used and the numerical simulations are validated by the experimental results in the literature. To augment the mixing performance, the effects of influencing...
Investigation of a two-step device implementing magnetophoresis and dielectrophoresis for separation of circulating tumor cells from blood cells
, Article Engineering in Life Sciences ; Volume 20, Issue 7 , 2020 , Pages 296-304 ; Yazdani, A ; Saghafifar, F ; Sharif University of Technology
Wiley-VCH Verlag
2020
Abstract
Identifying tumor cells from a pool of other cells has always been an appealing topic for different purposes. The objective of this study is to discriminate circulating tumor cells (CTCs) from blood cells for diagnostic purposes in a novel microfluidic device using two active methods: magnetophoresis and dielectrophoresis. The most specific feature of this device is the differentiation of CTCs without labeling them in order to achieve a more reliable and less complicated method. This device was analyzed and evaluated using finite element method. Four cell lines are separated in this device containing red blood cells, platelets, white blood cells, and CTCs. Primarily, red blood cells and...
Investigation of a Novel Microfluidic Device for Label-Free Ferrohydrodynamic Cell Separation on a Rotating Disk
, Article IEEE Transactions on Biomedical Engineering ; Volume 67, Issue 2 , 2020 , Pages 372-378 ; Besanjideh, M ; Sharif University of Technology
IEEE Computer Society
2020
Abstract
Negative magnetophoresis is a novel and attractive method for continuous microparticle sorting inside a magnetic medium. In this method, diamagnetic particles are sorted based on their sizes using magnetic buoyancy force and without any labeling process. Although this method provides some attractive features, such as low-cost fabrication and ease of operation, there are some obstacles that adversely affect its performance, especially for biological applications. Most types of magnetic media, such as ferrofluids, are not biocompatible, and the time-consuming process of sample preparation can be threatening to the viability of the cells within the sample. Furthermore, in this method, both the...
Pore scale visualization of fluid-fluid and rock-fluid interactions during low-salinity waterflooding in carbonate and sandstone representing micromodels
, Article Journal of Petroleum Science and Engineering ; 2020 ; Fatemi, M ; Masihi, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Low Salinity Waterflooding (LSWF) has become a popular tertiary injection EOR method recently. Both fluid-fluid and fluid-rock interactions are suggested as the contributing mechanisms on the effectiveness of LSWF. Considering the contradictory remarks in the literature, the dominating mechanisms and necessary conditions for Low Salinity Effect (LSE) varies for different crude oil-brine-rock (CBR) systems. The aim of the present study is to investigate LSE for an oil field in the Middle East that is composed of separate sandstone and limestone layers. Contact angles and Interfacial Tension (IFT) are measured to have more insight on the CBR under investigation. Visual experiments were...
Unsteady solute dispersion by electrokinetic flow in a polyelectrolyte layer-grafted rectangular microchannel with wall absorption
, Article Journal of Fluid Mechanics ; Volume 887 , 2020 ; Saidi, M. H ; Moosavi, A ; Sadeghi, A ; Sharif University of Technology
Cambridge University Press
2020
Abstract
The dispersion of a neutral solute band by electrokinetic flow in polyelectrolyte layer (PEL)-grafted rectangular/slit microchannels is theoretically studied. The flow is assumed to be both steady and fully developed and a first-order irreversible reaction is considered at the wall to account for probable surface adsorption of solutes. Considering low electric potentials, analytical solutions are obtained for electric potential, fluid velocity and solute concentration. Special solutions are also obtained for the case without wall adsorption. To track the dispersion properties of the solute band, the generalized dispersion model is adopted by considering the exchange, the convection and the...
Cost differential for deciding about installing information sharing technology in a two-echelon inventory system
, Article IIE Annual Conference and Expo 2007 - Industrial Engineering's Critical Role in a Flat World, Nashville, TN, 19 May 2007 through 23 May 2007 ; 2007 , Pages 1139-1144 ; Sajadifar, M ; Sharif University of Technology
2007
Abstract
We consider a dyadic supply chain. Retailer applies (R,Q)-policy. Supplier starts with m initial batches of size Q and places an order of the same size to an outside source. The supplier can select one of the two following cases. Case 1, whenever the retailer places an order, the supplier will also place an order. Case 2, whenever the retailer's inventory position reaches R+s, the supplier will place an order. This paper derives the cost differential between these cases for any value of s, which enables the supply chain managers to decide whether to install an information sharing technology
Splitting dynamics of ferrofluid droplets inside a microfluidic T-junction using a pulse-width modulated magnetic field in micro-magnetofluidics
, Article Soft Matter ; Volume 17, Issue 5 , 2021 , Pages 1317-1329 ; 1744683X (ISSN) ; Dizani, M ; Honarmand, M ; Shafii, M. B ; Sharif University of Technology
Royal Society of Chemistry
2021
Abstract
Micro-magnetofluidics offers a promising tool for better control over the ferrofluid droplet manipulation which has been vastly utilized in biomedical applications in recent years. In this study, the ferrofluid droplet splitting under an asymmetric Pulse-Width-Modulated (PWM) magnetic field in a T-junction is numerically investigated using a finite volume method and VOF two-phase model. By utilizing the PWM magnetic field, two novel regimes of ferrofluid droplet splitting named as Flowing through the Same Branch (FSB) and Double Splitting (DS) have been observed for the first time. In the FSB regime, the daughter droplets move out of the same microchannel outlet, and in the DS regime, the...
Pore-scale insights into sludge formation damage during acid stimulation and its underlying mechanisms
, Article Journal of Petroleum Science and Engineering ; Volume 196 , 2021 ; 09204105 (ISSN) ; Mahani, H ; Ayatollahi, S ; Mohammadzadeh Shirazi, M ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Acid-oil emulsion and sludge formation are known as two major formation damage mechanisms and the reason for failure of some acid treatments. The published studies in this area focus primarily on core- to well/reservoir-scale and it is fairly unclear how acid-oil interaction at the pore-scale leads to the formation damage observed at the macro- or core-scale. In this paper, dynamic, micro-scale experiments were designed and executed to investigate the acid-induced formation damage using microfluidic approach. In addition, a series of so-called static (microscope) tests were performed in which acid-crude oil compatibility tests were conducted on a glass slide followed by microscopic...
Diatoms with invaluable applications in nanotechnology, biotechnology, and biomedicine: Recent advances
, Article ACS Biomaterials Science and Engineering ; Volume 7, Issue 7 , 2021 , Pages 3053-3068 ; 23739878 (ISSN) ; Khatami, M ; Jamalipour Soufi, G ; Fatahi, Y ; Iravani, S ; Varma, R. S ; Sharif University of Technology
American Chemical Society
2021
Abstract
Diatoms are unicellular microalga found in soil and almost every aquatic environment (marine and fresh water). Biogenic silica and diatoms are attractive for biotechnological and industrial applications, especially in the field of biomedicine, industrial/synthetic manufacturing processes, and biomedical/pharmaceutical sciences. Deposition of silica by diatoms allows them to create micro- or nanoscale structures which may be utilized in nanomedicine and especially in drug/gene delivery. Diatoms with their unique architectures, good thermal stability, suitable surface area, simple chemical functionalization/modification procedures, ease of genetic manipulations, optical/photonic...