Search for: microfluidics
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    Design and Simulation of a Spiral Based Microfluidic Device for Separation of Circulating Tumor Cells Using Tunable Nature of Viscoelastic Fluid

    , M.Sc. Thesis Sharif University of Technology Nouri, Mohammad Moein (Author) ; Saeedi, Mohammad Saeed (Supervisor)
    Nowadays, cancer, which has been mentioned as the disease of the century, is the second leading cause of death throughout the world, and its incidence is constantly increasing. Isolation of circulating tumor cells is one of the most critical steps in diagnosing and controlling cancer progression. Due to the rarity of cancer cells compared to other cells in the blood sample, the isolation process requires optimal and high-precision devices. With the advent of inertial microfluidics, the ability to control the particles movement, the processing of blood samples as quickly and accurately as possible, and the viability of cells with a high percentage, introduced microfluidic systems as a... 

    Simulating of Droplet Formation and Calculation of Interfacial Tension by Microfluidic Method

    , M.Sc. Thesis Sharif University of Technology Ghanavati, Ashkan (Author) ; Mohammadi, Ali Asghar (Supervisor)
    Emulsions are the intermittent dispersion of liquid droplets that have many applications such as polymerization, dyeing, cosmetics, food industry, etc. Droplets can be created in a variety of ways, but the most important point in emulsification and the greatest efficiency of its applications is when the formed droplets are uniform. In the emulsification process, there is a key parameter called interfacial tension, which affects the behavior of the formed droplets, such as their stability and morphology, and its precise measurement is very effective in the quality control of the mentioned applications. Be. In this research, droplet formation in microfluidic systems due to uniform droplet... 

    Design and Fabrication of a 3D Multiparticle Microfluidic System

    , M.Sc. Thesis Sharif University of Technology Olyanasab, Ali (Author) ; Fardmanesh, Mehdi (Supervisor) ; Annabestani, Mohsen (Co-Supervisor)
    Microfluidic technology is a field of science that deals with the design, implementation, optimization, and testing of fluid systems in small dimensions. This technology has made significant progress in various fields in the last decade, especially in medical engineering. As an interdisciplinary scientific field, this growing technology has many applications in medicine, pharmaceuticals, chemistry, and electronic industries. One of the primary applications of microfluidic devices is the development of "lab-on-a-chip" systems as point-of-care diagnostic tools, such as rapid diagnosis during surgery. A microfluidic system includes various functional modules: sample preparation and fluid... 

    Simulation, Design, and Fabrication of a Droplet-Based Microfluidic Device to Study The Role of Tumor Microenvironment and Drug Effects on the Behavior of Multicellular Tumor Spheroids

    , Ph.D. Dissertation Sharif University of Technology Besanjideh, Mohsen (Author) ; Shamloo, Amir (Supervisor) ; Kazemzadeh Hannani, Siamak (Supervisor)
    Despite the extensive research conducted so far to treat cancer, this disease is still one of the main causes of death worldwide. The results of recent studies reveal the importance of the tumor microenvironment in the growth, proliferation, and invasion of the primary tumor. Most common models in cancer research, such as 2-dimensional in vitro models and xenografts, do not have sufficient ability to mimic the interaction of tumors with human stromal tissue. Therefore, the implementation of 3-dimensional in vitro models with the ability to replicate tumor microenvironments is essential. In this study, a microfluidic platform has been introduced to create parallel models of the tumor... 

    Selection and simulation of a proper microfluidic for hepatocyte culture

    , Article 2015 22nd Iranian Conference on Biomedical Engineering, ICBME 2015, 25 November 2015 through 28 November 2015 ; 2015 , Pages 65-69 ; 9781467393515 (ISBN) Nejadnasrollah, F ; Firoozabadi, B ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    The advent of microfluidics as suitable environments for culturing cells is associated with some challenges as shear stresses applied on the cells. Moreover, among all factors needed for cell viability, feeding hepatocytes with adequate oxygen is of great importance due to their high demand for oxygen compared the other cell types. In this paper three kinds of geometries has been studied in order that shear stresses would be in allowed range and provision of hepatocytes with sufficient oxygen concentrations has been ensured as well. In addition to supplying hepatocytes with oxygen, the range of its concentration has been adjusted in physiologic value so that it would be practical for further... 

    Microfluidic-based multi-organ platforms for drug discovery

    , Article Micromachines ; Volume 7, Issue 9 , 2016 ; 2072666X (ISSN) Rezaei Kolahchi, A ; Khadem Mohtaram, N ; Pezeshgi Modarres, H ; Mohammadi, M. H ; Geraili, A ; Jafari, P ; Akbari, M ; Sanati Nezhad, A ; Sharif University of Technology
    MDPI AG 
    Development of predictive multi-organ models before implementing costly clinical trials is central for screening the toxicity, efficacy, and side effects of new therapeutic agents. Despite significant efforts that have been recently made to develop biomimetic in vitro tissue models, the clinical application of such platforms is still far from reality. Recent advances in physiologically-based pharmacokinetic and pharmacodynamic (PBPK-PD) modeling, micro- and nanotechnology, and in silico modeling have enabled single- and multi-organ platforms for investigation of new chemical agents and tissue-tissue interactions. This review provides an overview of the principles of designing... 

    Numerical optimization and inverse study of a microfluidic device for blood plasma separation

    , Article European Journal of Mechanics, B/Fluids ; Volume 57 , 2016 , Pages 31-39 ; 09977546 (ISSN) Shamloo, A ; Vatankhah, P ; Bijarchi, M. A ; Sharif University of Technology
    Elsevier Ltd  2016
    In this paper, a passive microfluidic device for continuous real time blood plasma separation has been studied and optimized. A numerical model is used to solve both the fluid flow and the particles confined within it. Red blood cells are considered as particles with diameter of 7μm. A parametric study is performed in order to characterize the effect of different parameters on separation and purity efficiency. In this study, four different variables were introduced to design the microfluidic device for blood plasma separation including: the angle between the daughter channels and the main channel, the widths, the diffuse angle and the number of daughter channels. Results show that the... 

    Spiral microchannel with stair-like cross section for size-based particle separation

    , Article Microfluidics and Nanofluidics ; Volume 21, Issue 7 , 2017 ; 16134982 (ISSN) Ghadami, S ; Kowsari Esfahan, R ; Saidi, M. S ; Firoozbakhsh, K ; Sharif University of Technology
    Springer Verlag  2017
    Particle separation has a variety of applications in biology, chemistry and industry. Among them, circulating tumor cells (CTCs) separation has drawn significant attention to itself due to its high impact on both cancer diagnosis and therapeutics. In recent years, there has been growing interest in using inertial microfluidics to separate micro/nano particles based on their sizes. This technique offers label-free, high-throughput and efficient separation and can be easily fabricated. However, further improvements are needed for potential clinical applications. In this study, a novel inertial separation technique using spiral microchannel having stair-like cross section is introduced. The... 

    Modeling of microfluidic microbial fuel cells using quantitative bacterial transport parameters

    , Article Journal of Power Sources ; Volume 342 , 2017 , Pages 1017-1031 ; 03787753 (ISSN) Mardanpour, M. M ; Yaghmaei, S ; Kalantar, M ; Sharif University of Technology
    Elsevier B.V  2017
    The objective of present study is to analyze the dynamic modeling of bioelectrochemical processes and improvement of the performance of previous models using quantitative data of bacterial transport parameters. The main deficiency of previous MFC models concerning spatial distribution of biocatalysts is an assumption of initial distribution of attached/suspended bacteria on electrode or in anolyte bulk which is the foundation for biofilm formation. In order to modify this imperfection, the quantification of chemotactic motility to understand the mechanisms of the suspended microorganisms’ distribution in anolyte and/or their attachment to anode surface to extend the biofilm is implemented... 

    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) Mashhadian, A ; Shamloo, A ; Sharif University of Technology
    Elsevier B.V  2019
    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... 

    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) Mahmoudifard, M ; Vossoughi, M ; Soleimani, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2019
    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... 

    Improvement of size-based particle separation throughput in slanted spiral microchannel by modifying outlet geometry

    , Article Electrophoresis ; Volume 41, Issue 5-6 , February , 2020 , Pages 353-359 Mihandoust, A ; Maleki Jirsaraei, N ; Rouhani, S ; Safi, S ; Alizadeh, M ; Sharif University of Technology
    Wiley-VCH Verlag  2020
    The inertial microfluidic technique, as a powerful new tool for accurate cell/particle separation based on the hydrodynamic phenomenon, has drawn considerable interest in recent years. Despite numerous microfluidic techniques of particle separation, there are few articles in the literature on separation techniques addressing external outlet geometry to increase the throughput efficiency and purity. In this work, we report on a spiral inertial microfluidic device with high efficiency (>98%). Herein, we demonstrate how changing the outlet geometry can improve the particle separation throughput. We present a complete separation of 4 and 6 μm from 10 μm particles potentially applicable to... 

    Computational inertial microfluidics: a review

    , Article Lab on a Chip ; Volume 20, Issue 6 , 2020 , Pages 1023-1048 Razavi Bazaz, S ; Mashhadian, A ; Ehsani, A ; Saha, S. C ; Krüger, T ; Ebrahimi Warkiani, M ; Sharif University of Technology
    Royal Society of Chemistry  2020
    Since the discovery of inertial focusing in 1961, numerous theories have been put forward to explain the migration of particles in inertial flows, but a complete understanding is still lacking. Recently, computational approaches have been utilized to obtain better insights into the underlying physics. In particular, fundamental aspects of particle focusing inside straight and curved microchannels have been explored in detail to determine the dependence of focusing behavior on particle size, channel shape, and flow Reynolds number. In this review, we differentiate between the models developed for inertial particle motion on the basis of whether they are semi-analytical, Navier-Stokes-based,... 

    Fabrication of a microdialysis-based nonenzymatic microfluidic sensor for regular glucose measurement

    , Article Sensors and Actuators, B: Chemical ; Volume 333 , 2021 ; 09254005 (ISSN) Najmi, A ; Saidi, M. S ; Shahrokhian, S ; Hosseini, H ; Kazemzadeh Hannani, S ; Sharif University of Technology
    Elsevier B.V  2021
    Microdialysis-based continuous glucose measuring systems are desirable candidates for accurate and biologically safe monitoring of glucose level in diabetic patients. However, it is necessary to improve these systems by utilizing highly reliable non-enzymatic sensors instead of enzymatic ones, while lowering the size and lessening the dialysis fluid consumption. Our purpose is to design an implantable integrated microfluidic device for regular nonenzymatic microdialysis-based glucose measurement. We report a novel nonenzymatic microfluidic glucose sensor based on Pt-Ni nanoparticles - multiwalled carbon nanotubes/screen-printed carbon electrode (Pt-Ni NPs-MWCNTs/SPE). Devised microfluidic... 

    Design of a hybrid inertial and magnetophoretic microfluidic device for ctcs separation from blood

    , Article Micromachines ; Volume 12, Issue 8 , 2021 ; 2072666X (ISSN) Nasiri, R ; Shamloo, A ; Akbari, J ; Sharif University of Technology
    MDPI AG  2021
    Circulating tumor cells (CTCs) isolation from a blood sample plays an important role in cancer diagnosis and treatment. Microfluidics offers a great potential for cancer cell separation from the blood. Among the microfluidic-based methods for CTC separation, the inertial method as a passive method and magnetic method as an active method are two efficient well-established methods. Here, we investigated the combination of these two methods to separate CTCs from a blood sample in a single chip. Firstly, numerical simulations were performed to analyze the fluid flow within the proposed channel, and the particle trajectories within the inertial cell separation unit were investigated to... 

    Design of two Inertial-based microfluidic devices for cancer cell separation from Blood: A serpentine inertial device and an integrated inertial and magnetophoretic device

    , Article Chemical Engineering Science ; 2021 ; 00092509 (ISSN) Nasiri, R ; Shamloo, A ; Akbari, J ; Sharif University of Technology
    Elsevier Ltd  2021
    The separation of cancer cells from a heterogeneous biological sample such as blood plays a vital role in cancer study and future treatments. In this paper, we designed and investigated two microfluidic devices for cancer cell separation, including a serpentine inertial device and an integrated inertial-magnetophoretic device. Firstly, numerical modeling was carried out to study the fluid flow, particles’ trajectories in the inertial device. Then the device was fabricated using soft photolithography and suspension of two types of microparticles with the size of 10 and 15 µm were injected into the microchannel separately to investigate the particles’ trajectories and focusing behavior at... 

    Bacterial receiver prototype for molecular communication using rhamnose operon in a microfluidic environment

    , Article IEEE Transactions on Nanobioscience ; Volume 20, Issue 4 , 2021 , Pages 426-435 ; 15361241 (ISSN) Amerizadeh, A ; Mashhadian, A ; Farahnak Ghazani, M ; Arjmandi, H. R ; Alsadat Rad, M ; Shamloo, A ; Vosoughi, M ; Nasiri Kenari, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Bacterial populations are promising candidates for the development of the receiver and transmitter nanomachines for molecular communication (MC). A bacterial receiver is required to uptake the information molecules and produce the detectable molecules following a regulation mechanism. We have constructed a novel bacterial MC receiver using an inducible bacterial L-rhamnose-regulating operon. The proposed bacterial receiver produces green fluorescent protein (GFP) in response to the L-rhamnose information molecules following a quite fast regulation mechanism. To fabricate the receiver, the bacterial population has been transformed using a plasmid harboring L-rhamnose operon genes and gene... 

    Rapid Determination of Histamine by an Enzyme-based Microfluidic Biosensor

    , M.Sc. Thesis Sharif University of Technology Moradi, Mohammad Reza (Author) ; Vossoughi, Manouchehr (Supervisor) ; Shamloo, Amir (Supervisor)
    Design, simulation, optimization and manufacturing of an enzyme-based microfluidic biosensor has been carried out during this research to measure histamine concentration in a sample. The designed biosensor is composed of a micro-bioreactor to degrade histamine and yield hydrogen peroxide, and a chemical reactor to measure the amount of hydrogen peroxide, using chemiluminescence methods. The geometry of the bioreactor and chemical reactor is developed through comparison and optimization of several different geometries. In theory, the designed sensor can determine histamine concentration in a range of 10M to 1mM under one minute, with a maximum error of 5%. Designed biosensor is built using... 

    Numerical Simulation of Glucose Metabolism and Hepatocyte Viability within a Microfluidic

    , M.Sc. Thesis Sharif University of Technology Nejadnasrollah, Farzam (Author) ; Firoozabadi, Bahar (Supervisor)
    The advent of microfluidics as suitable environments for culturing cells is associated with some challenges such as shear stresses applied on the cells. In fact, hepatocytes lose their function as exposed to high shear stresses similar to other cell types. Moreover, among all factors needed for cell viability, feeding hepatocytes with adequate oxygen is of great importance due to their high demand for oxygen compared the other cells. In this thesis, different types of cultures including 2D and 3D has been used in order that shear stresses would be in allowed range and provision of hepatocytes with sufficient oxygen concentrations has been ensured as well. In addition to supplying hepatocytes... 

    Investigation of the Geometry Effect on Electrokinetic Instability in Microflows

    , M.Sc. Thesis Sharif University of Technology Mohammadzadeh, Alireza (Author) ; Saidi, Mohammad Hassan (Supervisor)
    Lab-on-a-chip devices have gained a lot of attention in chemical and biomedical analyses during the past two decades. These devices employ microfluidics basics and fundamentals to combine multifold laboratory processes in one single portable chip. The electric field has been often used in most microfluidics applications for the ease of sample control as well as become easily integrated to other chip components. Instabilities in microflows would occur when two fluids of different electric properties are exposed to an adequately strong electric field. Studying these electrokinetic instabilities is not only important for the fundamental studies but also for practical applications in micromixers...