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microfluidics
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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...
Microfluidic devices with gold thin film channels for chemical and biomedical applications: a review
, Article Biomedical Microdevices ; Volume 21, Issue 4 , 2019 ; 13872176 (ISSN) ; Rabiee, N ; Rabiee, M ; Bagherzadeh, M ; Tahriri, M ; Tayebi, L ; Hamblin, M. R ; Sharif University of Technology
Springer New York LLC
2019
Abstract
Microfluidic systems (MFS) provide a range of advantages in biomedical applications, including improved controllability of material characteristics and lower consumption of reagents, energy, time and money. Fabrication of MFS employs various materials, such as glass, silicon, ceramics, paper, and metals such as gold, copper, aluminum, chromium and titanium. In this review, gold thin film microfluidic channels (GTFMFC) are discussed with reference to fabrication methods and their diverse use in chemical and biomedical applications. The advantages of gold thin films (GTF) include flexibility, ease of manufacture, adhesion to polymer surfaces, chemical stability, good electrical conductivity,...
Inertial microfluidics: a method for fast prediction of focusing pattern of particles in the cross section of the channel
, Article Analytica Chimica Acta ; Volume 1083 , 2019 , Pages 137-149 ; 00032670 (ISSN) ; Shamloo, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Inertial microfluidics is utilized as a powerful passive method for particle and cell manipulation, which uses the hydrodynamic forces of the fluid in the channel to focus particles in specific equilibrium positions in the cross section of the channel. To achieve high performance manipulation, knowledge of focusing pattern of particles in the cross section of channel is essential. In this paper, we propose a method to address this important issue. To this end, firstly inertial microfluidics is analyzed in rectangular cross section channels. The results indicate that fluid flow velocity and channel's cross-sectional profiles have great impacts on the forces exerted on particles. Next, these...
Exploring contraction–expansion inertial microfluidic-based particle separation devices integrated with curved channels
, Article AIChE Journal ; Volume 65, Issue 11 , 2019 ; 00011541 (ISSN) ; Abdorahimzadeh, S ; Nasiri, R ; Sharif University of Technology
John Wiley and Sons Inc
2019
Abstract
Separation of particles or cells has various applications in biotechnology, pharmaceutical and chemical industry. Inertial cell separation, in particular, has been gaining a great attention in the recent years since it has exhibited a label-free, high-throughput and efficient performance. In this work, first, an inertial contraction–expansion array microchannel device, capable of passively separating two particles with diameters of 4 and 10 μm, was numerically studied. Then, the validated model was combined with curved geometries in order to investigate the effect of curve features on the separation process. The overall purpose was to investigate the interaction between the two different...
Numerical simulation of a microfluidic system for regular glucose measurement
, Article 26th National and 4th International Iranian Conference on Biomedical Engineering, ICBME 2019, 27 November 2019 through 28 November 2019 ; 2019 , Pages 60-65 ; 9781728156637 (ISBN) ; Saidi, M. S ; Shahrokhian, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
The aim of this research is to design an implantable integrated microfluidic system in order to regularly measure the glucose level in the human body, nonenzymatically, using the microdialysis method. The main compartments of this system are a micropump, array of hollow microneedles and an electrochemical sensor. At the base of the microneedles, there are located semipermeable membranes, that when the pumped dialysis fluid passes over them, the glucose of the interstitial fluid diffuses into the dialysis fluid and then, in the sensor section, it is measured nonenzymatically using the amperometry method. Both the arrangement of the miconeedles and the amount of the dialysis fluid flow are...
Improvement of the microfluidic microbial fuel cell using a nickel nanostructured electrode and microchannel modifications
, Article Journal of Power Sources ; Volume 437 , 2019 ; 03787753 (ISSN) ; Ghasemi, S ; Sanaee, Z ; Ghobadi Nejad, Z ; Mardanpour, M. M ; Yaghmaei, S ; Ghorbanzadeh, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this study, the effect of utilization of a nanostructured nickel based material as a negative electrode on the performance of microfluidic microbial fuel cell (MFC) with Escherichia coli as biocatalyst has been investigated. Designing the microfluidic MFC with nickel nanostructure resulted in a higher volumetric power density of 343 W m−3 compared to the previously published results. The assessment of effective parameters on the electrochemical performance of cell was investigated. The investigation of the hydraulic diameter impact on the power generation proves that reducing the microchannel hydraulic diameter from 1000 to 350 μm minimized the internal mass-transfer resistance, and...
Design and fabrication of a novel microfluidic system for enrichment of circulating tumor cells with the assistance of computer simulations
, Article Avicenna Journal of Medical Biotechnology ; Volume 11, Issue 4 , 2019 , Pages 277-284 ; 20082835 (ISSN) ; Vossoughi, M ; Alemzadeh, I ; Sharif University of Technology
Avicenna Research Institute
2019
Abstract
Background: Cancer is the first cause of death in developed countries. The heterogeneous nature of cancer requires patient-specified treatment plans. One reliable approach is collecting Circulating Tumour Cells (CTCs) and using them for prognosis and drug response assessment purposes. CTCs are rare and their separation from normal cell requires high-accuracy methods. Methods: A microfluidic cell capture device to separate CTCs from peripheral blood is presented in this study. The CTC separation device applies hydrodynamic forces to categorize cells according to their sizes. The proposed device is designed and evaluated by numerical simulations and validated experimentally. The simulation...
Toward higher extraction and enrichment factors via a double-reservoirs microfluidic device as a micro-extractive platform
, Article Journal of Separation Science ; Volume 42, Issue 18 , 2019 , Pages 2985-2992 ; 16159306 (ISSN) ; Baraazandeh, M ; Bagheri, H ; Sharif University of Technology
Wiley-VCH Verlag
2019
Abstract
In this study, firstly, a double-reservoir and switchable prototype of a micro-chip along with the respective holders were fabricated. A cyclic desorption process using microliter volume of organic solvent was adopted to prevent any outdoor contamination. As extractive phases, two identical sheets of electrospun polyamide/polypyrrole/titania nanofibers were synthesized using core–shell electro-spinning technique and utilized for determination of memantine in plasma samples. Field emission scanning electron microscopy images showed a high degree of porosity and homogeneity throughout the sheet structure. Also, energy dispersive X-ray analysis confirmed the presence of titania, while the...
Continuous synthesis of plate-like silica microparticles using microfluidics
, Article Journal of Flow Chemistry ; Volume 9, Issue 3 , 2019 , Pages 161-174 ; 2062249X (ISSN) ; Mohammadi, A ; Sharif University of Technology
Springer International Publishing
2019
Abstract
The synthesis of plate-like silica particles, which are of importance for a variety of applications, are mainly based on the widely adopted method of the sol-gel reaction of silicon alkoxides in traditional batch-wise instrumentation. In this study, continuous-flow synthesis of amorphous plate-like silica particles is reported through combining droplet-based microfluidics and the sol-gel reaction of tetraethyl orthosilicate. The reaction was conducted at the surface of oil droplets, comprising tetraethyl orthosilicate (TEOS), suspended in acidic (HCl) water, resulting in silica particles on the surface of the droplets, leaving the device with outlet flow. The synthesized particles had...
Three-dimensional modeling of avascular tumor growth in both static and dynamic culture platforms
, Article Micromachines ; Volume 10, Issue 9 , 2019 ; 2072666X (ISSN) ; Barisam, M ; Saidi, M. S ; Kashaninejad, N ; Nguyen, N. T ; Sharif University of Technology
MDPI AG
2019
Abstract
Microfluidic cell culture platforms are ideal candidates for modeling the native tumor microenvironment because they can precisely reconstruct in vivo cellular behavior. Moreover, mathematical modeling of tumor growth can pave the way toward description and prediction of growth pattern as well as improving cancer treatment. In this study, a modified mathematical model based on concentration distribution is applied to tumor growth in both conventional static culture and dynamic microfluidic cell culture systems. Apoptosis and necrosis mechanisms are considered as the main inhibitory factors in the model, while tumor growth rate and nutrient consumption rate are modified in both quiescent and...
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...
Interpretation of the electrochemical response of a multi-population biofilm in a microfluidic microbial fuel cell using a comprehensive model
, Article Bioelectrochemistry ; Volume 128 , 2019 , Pages 39-48 ; 15675394 (ISSN) ; Saadatmand, M ; Yaghmaei, S ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The present study investigates the diversification and dynamic behavior of a multi-population microfluidic microbial fuel cell (MFC) as a biosensor. The cost effective microfluidic MFC coupled to a comprehensive model, presents a novel platform for monitoring chemical and biological phenomena. The importance of competition among different microbial groups, hierarchical biochemical processes, bacterial chemotaxis and different mechanisms of electron transfer were significant considerations in the present model. The validation of the model using experimental data from a microfluidic MFC shows an appropriate match with the hierarchal biodegradation processes of a complex substrate as well as...
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...
Novel microfluidic graphene oxide–protein amperometric biosensor for detecting sulfur compounds
, Article Biotechnology and Applied Biochemistry ; Volume 66, Issue 3 , 2019 , Pages 353-360 ; 08854513 (ISSN) ; Abdi, K ; Javadi, S ; Shehneh, M. Z ; Yazdian, F ; Omidi, M ; Rashedi, H ; Haghiralsadat, B. F ; Asayeshnaeini, O ; Sharif University of Technology
Wiley-Blackwell Publishing Ltd
2019
Abstract
Sulfur compounds are essential for many industries and organisms; however, they cause serious respiratory problems in human beings. Therefore, determination of sulfur concentration is of paramount importance. The research approach in the field of detecting contaminants has led to smaller systems that provide faster and more effective ways for diagnosis purposes. In this study, a novel portable amperometric graphene oxide–protein biosensor platform is investigated. The main characteristic of this structure is the implementation of a microfluidic configuration. With albumin metalloprotein as the biorecognition element, graphene oxide was synthesized and characterized by transmission electron...
Active microfluidic micromixer design using ionic polymer-metal composites
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 371-375 ; 9781728115085 (ISBN) ; Mohammadzadeh, H ; Aghassizadeh, A ; Azizmohseni, S ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In most of the microfluidic applications, it is necessary to have a mixed fluid from the beginning, but in microchannels, due to facing with low Reynolds flows, the fluids flow in the channel by the laminar regimes. Hence the mixing process is a challenging problem and researchers are trying to present fast and reliable micromixers. In this paper, using Ionic Polymer-Metal Composites (IPMCs), an active micromixer has been designed. To investigate the appropriateness of IPMC, using experimental and simulation tests, we show that the IPMC actuator is a potential candidate as an active element of microfluidic micromixers
Different types of electrospun nanofibers and their effect on microfluidic-based immunoassay
, Article Polymers for Advanced Technologies ; Volume 30, Issue 4 , 2019 , Pages 973-982 ; 10427147 (ISSN) ; Vossoughi, M ; Soleimani, M ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
Protein capturing on polymeric substrate of microfluidic devices is a key factor for the fabrication of immunoassay with high sensitivity. In this work, simple and versatile technique of electrospinning was used to produce electrospun nanofibrous membranes (e.NFMs) with high surface area as a substrate for microfluidic-based immunoassay to increase sensitivity. It was found that the simultaneous use of e.NFM and 1-Ethylethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-Hydroxysuccinimide hydroxysuccinimide as coupling agent has synergic effect on antigen immobilization onto the microchannels. It was found that the oxygen plasma technique for the creation of oxygen containing functional group...
Numerical simulation of mixing and heat transfer in an integrated centrifugal microfluidic system for nested-PCR amplification and gene detection
, Article Sensors and Actuators, B: Chemical ; Volume 283 , 2019 , Pages 831-841 ; 09254005 (ISSN) ; Ghazimirsaeed, E ; Shamloo, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Nucleic acid amplification via polymerase chain reaction (PCR) is one of the essential and powerful methods used in a myriad of bio-assays in clinical laboratories. Application of microfluidic devices in biologically-related processes like PCR can result in the usage of less volume of reactant samples and reduce the processing time. By implementing PCR systems on centrifugal microfluidic platforms, automation and portability can be easily achieved. Although several methods have been developed, most of them are still dealing with challenges of the required high processing time. This study presents the numerical simulation of a fully automated PCR system with the goal of enhancing the mixing...
A novel approach for microparticle separation based on dielectrophoresis method
, Article Biomedical Physics and Engineering Express ; Volume 5, Issue 3 , 2019 ; 20571976 (ISSN) ; Sasanpour, P ; Fardindoost, S ; Irajizad, A ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
A novel approach for particles size separation based on dielectrophoresis (DEP) method is introduced and analyzed both computationally and experimentally. The proposed technique has been utilized for the separation of polystyrene (PS) particles with 8, 6 and 2 μm diameters passing through microchannels with planar electrodes. The performance of the technique has been computationally analyzed using the finite element method (FEM). Considering the structure of the planar electrodes, we propose an approach based on applying an electric potential between one of the global electrodes, and a needle touched the top of the cell suspension. Results of both simulation and experiment show that by...
Novel approaches in cancer management with circulating tumor cell clusters
, Article Journal of Science: Advanced Materials and Devices ; Volume 4, Issue 1 , 2019 , Pages 1-18 ; 24682284 (ISSN) ; Kashaninejad, N ; Moshksayan, K ; Saidi, M. S ; Firoozabadi, B ; Nguyen, N. T ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Tumor metastasis is responsible for the vast majority of cancer-associated morbidities and mortalities. Recent studies have disclosed the higher metastatic potential of circulating tumor cell (CTC) clusters than single CTCs. Despite long-term study on metastasis, the characterizations of its most potent cellular drivers, i.e., CTC clusters have only recently been investigated. The analysis of CTC clusters offers new intuitions into the mechanism of tumor metastasis and can lead to the development of cancer diagnosis and prognosis, drug screening, detection of gene mutations, and anti-metastatic therapeutics. In recent years, considerable attention has been dedicated to the development of...
A new non-dimensional parameter to obtain the minimum mixing length in tree-like concentration gradient generators
, Article Chemical Engineering Science ; Volume 195 , 2019 , Pages 120-126 ; 00092509 (ISSN) ; Saidi, M. S ; Kashaninejad, N ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Microfluidic-based concentration gradient generators (CGGs) have a number of applications in chemical, biological and pharmaceutical studies. Thus, precise design of the microfluidic system is crucial to maintaining the desired concentration gradient in microchannels. One of the design considerations is the length of microchannels in the structure of a CGG. A CGG with a short length fails to provide the complete diffusive mixing, while the size of the microchip would unfavorably increase by incorporating a long CGG. Considering a CGG as a tree-like structure consisting of T-shaped micromixers, the mixing process of the species at a straight microchannel has been solved analytically. Herein,...