Search for: microfluidics
Total 287 records
M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir
Nowadays, separation and filtration of particles has many industrial applications in biology and medicine. In this thesis, passive microfluidics are designed and simulated which are able to separate and filter particles. Although particles aer generally expected to follow laminar flow streamlines in the absence of external forces, inertial forxes van cause particles to migrate across mictochannels in an accurate and predictable manner. The effect of these forces is invedtigated, and by using previous research, a model is developed to predict these forces. First design is a microchannel with Archimedean spiral which utilizes both inertial forces and Dean flow to separate particles in the...
M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi
Microfluidic technology is a field of science that deals with the design, fabrication, and experimental tests of small-scale fluid systems and has made great strides over the past decade. As an interdisciplinary field, this growing field of technology has many applications in medicine, diagnostics, chemical analysis, electronics industry, etc. One of the primary applications of the microfluidic devices is the development of " laboratory on-chip (LOC)" tools as point-of-care (POC) diagnostic tools, such as, rapid detection during surgery. A LOC device includes various application modules, sample transfer and preparation modules, separation modules, and detection and analysis modules. The...
Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 91, Issue 5 , May , 2015 ; 15393755 (ISSN) ; Moosavi, A ; Hannani, S. K ; Sharif University of Technology
American Physical Society 2015
We develop accurate analytical relations for the droplet volume ratio, droplet length during breakup process, and pressure drop of asymmetric T junctions with a valve in each of the branches for producing unequal-sized droplets. An important advantage of this system is that after manufacturing the system, the size of the generated droplets can be changed simply by adjusting the valves. The results indicate that if the valve ratio is smaller than 0.65, the system enters a nonbreakup regime. Also the pressure drop does not depend on the time and decreases by increasing the valve ratio, namely, opening the degree of valve 1 to valve 2. In addition, the results reveal that by decreasing...
Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 82, Issue 3 , September , 2010 ; 15393755 (ISSN) ; Seyed Allaei, H ; Ejtehadi, M. R ; Sharif University of Technology
We show that in a microfluidic network with low Reynolds numbers, a system can be irreversible due to hysteresis effects. We simulated a network of pipes that was used in a recent experiment. The network consists of one loop connected to input and output pipes. A train of droplets enters the system at a uniform rate, but the droplets may leave the system in a periodic or even a chaotic pattern. The output pattern depends on the time interval between incoming droplets as well as the network geometry. For some parameters, the system is not reversible
A comparison of different geometrical elements to model fluid wicking in paper-based microfluidic devices, Article AIChE Journal ; Volume 66, Issue 1 , 2020 ; Shamloo, A ; Sharif University of Technology
John Wiley and Sons Inc 2020
Recently, microfluidic paper-based analytical devices (μPADs) have outstripped polymeric microfluidic devices in the ease of fabrication and simplicity. Surface tension-based fluid motion in the paper's porous structure has made the paper a suitable substrate for multiple biological assays by directing fluid into multiple assay zones. The widespread assumption in most works for modeling wicking in a paper is that the paper is a combination of capillaries with the same diameter equal to the effective pore diameter. Although assuming paper as a bundle of capillaries gives a good insight into pressure force that drives the fluid inside the paper, there are some difficulties using the effective...
M.Sc. Thesis Sharif University of Technology ; Mohammadi, Aliasghar ; Kazemeini, Mohammad
Microfluidic is a science and technology in which they study the behavior of fluids, control them and design devices or systems with dimensions of tens to hundreds of micrometers. The technology has the ability to design and manufacture macro-scale and micro-scale equipment, such as micro-pumps, micro-valves, micro-filters, micro-mixers, micro-reactors, and other equipment. The benefits of this technology include the use of low sample size, low waste of energy, low power consumption, short response time, high system performance, portability and performance of several operating phases in a compressed piece such as production, isolation and analysis. Also, the very low amount of chemicals and...
Design and Fabrication of Micro-Fluidic Chip for Formation, Culture and Analysis of Cancer Tumor Cell Spheroids, M.Sc. Thesis Sharif University of Technology ; Saeedi, Mohammad Saeed ; Kazemzadeh Hannani, Siamak
Simulating the in-vivo environment of cancer tumors outside the body, can provide an appropriate condition for studying different key processes of the tumor micro-environment, such as aggregation, formation, growth, angiogenesis and metastasis of the cancer tumor cells, which can be useful in finding methods to cure, or at least control cancer. Every year, a variety of drugs are being developed to overcome cancer, all of which need to be experimented. Although, these drugs are now experimented on animals, and some human volunteers, the reaction of different patients’ cancer cells to different drugs may differ with the experimented animals, or even with other people. So, there needs to be a...
Article Cytoskeleton ; Vol. 71, issue. 9 , 2014 , p. 501-512 ; Sharif University of Technology
This study investigates the role of cell-cell and cell-ligand interactions in cytoskeleton organization of endothelial cells (ECs) and their directional migration within a microfluidic device. The migration of ECs in response to a biochemical factor was studied. Mathematical analysis of the cell migration pathways and cellular cytoskeleton revealed that directional migration, migration persistence length, migration speed, and cytoskeletal stress fiber alignment can be mediated by the level of cell contacts as well as the presence or absence of a biochemical polarizing factor. It was shown that in the presence of a biochemical polarizing factor, higher cell density and more frequent cell...
Microfluidic manipulation of Core/Shell nanoparticles for oral delivery of chemotherapeutics: A new treatment approach for colorectal cancer, Article Advanced Materials ; Volume 28, Issue 21 , 2016 , Pages 4134-4141 ; 09359648 (ISSN) ; Taranejoo, S ; Dashtimoghadam, E ; Bahlakeh, G ; Majedi, F.S ; Vandersarl, J. J ; Janmaleki, M ; Sharifi, F ; Bertsch, A ; Hourigan, K ; Tayebi, L ; Renaud, P ; Jacob, K. I ; Sharif University of Technology
A microfluidics approach to synthesize core-shell nanocarriers with high pH tunability is described. The sacrificial shell protects the core layer with the drugs and prevents their release in the severe pH conditions of the gastrointestinal tract, while allowing for drug release in the proximity of a tumor. The proposed nanoparticulate drug-delivery system is designed for the oral administration of cancer therapeutics
Immobilization of functionalized gold nanoparticles in a well-organized silicon-based microextracting chip followed by online thermal desorption-gas chromatography, Article Microchemical Journal ; Volume 143 , 2018 , Pages 205-211 ; 0026265X (ISSN) ; Bagheri, H ; Zamani, C ; Sharif University of Technology
Elsevier Inc 2018
In this survey, firstly, a silicon wafer-based microchip, possessing a 50-cm microchannel with the dimensions of 120 and 60 μm, was manufactured by chemical etching technique. Subsequently, the inner surface of the microchannel was coated with a primary layer of gold nanoparticles synthesized by galvanic displacement. Then a self-assembled monolayer of 3-mercaptopropyltriethoxysilane was immobilized on the first layer. Eventually, a polydimethylsiloxane film with a thickness of 16 ± 1 μm was formed on the walls of the microchannel by means of sol-gel method. Field emission scanning electron microscopy and atomic force microscopy were extensively employed to investigate the status of both...
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
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...
The effects of thymus plant extracts on single breast cancer cell morphology in the microfluidic channel, Article 2018 IEEE EMBS Conference on Biomedical Engineering and Sciences, IECBES 2018, 3 December 2018 through 6 December 2018 ; 2019 , Pages 647-651 ; 9781538624715 (ISBN) ; Mansor, M. A ; Alsadat Rad, M ; Soo-Beng Khoo, A ; Ahmad, M ; Marzuki, M ; Physiological Measurement; Sarawak Convention Bureau ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2019
Microfluidics based systems could be useful for drug discovery as they allow for miniaturization and could potentially be run as multiple parallel cell based assays. Such miniaturization allows assays at single cell level and reduces the amount of test material needed, which, in the case of natural product extracts, simplifies the preparation. Thyme species extracts have been reported to show some promising anti-cancer effects. In the present work, we used a microfluidics based system to study the effects of Thymus kotschyanusm Boiss plant extract on two human breast cancer cells lines which are MDA-MB-231 and MCF-7. For better understanding a single cancer cell death mechanism and a flow...
Design and simulation of an integrated centrifugal microfluidic device for CTCs separation and cell lysis, Article Micromachines ; Volume 11, Issue 7 , July , 2020 ; Shamloo, A ; Akbari, J ; Tebon, P ; Dokmeci, M. R ; Ahadian, S ; Sharif University of Technology
MDPI AG 2020
Separation of circulating tumor cells (CTCs) from blood samples and subsequent DNA extraction from these cells play a crucial role in cancer research and drug discovery. Microfluidics is a versatile technology that has been applied to create niche solutions to biomedical applications, such as cell separation and mixing, droplet generation, bioprinting, and organs on a chip. Centrifugal microfluidic biochips created on compact disks show great potential in processing biological samples for point of care diagnostics. This study investigates the design and numerical simulation of an integrated microfluidic device, including a cell separation unit for isolating CTCs from a blood sample and a...
Fluidic barriers in droplet-based centrifugal microfluidics: Generation of multiple emulsions and microspheres, Article Sensors and Actuators, B: Chemical ; Volume 311 , May , 2020 ; Madou, M. J ; Dorri Nokoorani, Y ; Shamloo, A ; Martinez Chapa, S. O ; Sharif University of Technology
Elsevier B. V 2020
Droplet generation is very important in biochemical processes such as cell encapsulation, digital PCR (Polymerase Chain Reaction), and drug delivery. In the present paper, a density-based method called “fluidic barrier” is introduced to produce multiple emulsions on a centrifugal microfluidic platform or Lab-on-a-CD (LOCD). We show that the density and the viscosity of the fluids involved are important parameters for predicting the characteristics of the droplets generated with this method. Moreover, we broadened this concept by using the fluidic barriers to separate reactive chemicals. As a proof of concept, alginate and CaCl2 solutions are separated by an oil barrier to control the...
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
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...
M.Sc. Thesis Sharif University of Technology ; Mashayekhan, Shohreh ; Saadatmand, Maryam
Myocardial infarction (MI) is one of the diseases caused by the temporary or permanent cramp of major coronary arteries. Due to this blockage, blood flow to the heart's myocardial tissue is greatly reduced and finally the person suffered from a Heart stroke (HS). Heart tissue engineering is a promising approach, based on the combination of cells and suitable biomaterials to develop and create heart-like biological substitutes. Since high cardiac cell density, providing metabolic needs like oxygen and nutrients was a challenge. So creation of blood vessel networks within this type of designed tissue has been considered very much.The purpose of this project is to construct scaffolds with...
M.Sc. Thesis Sharif University of Technology ; Saeedi, Mohammad Saeed ; Hajilouy Benisi, Ali ; Moghadas, Hajar
In this manuscript, we designed and fabricated a novel integrated microfluidic Kidney Nephron-On-Chip. This chip is able to culture cell monolayers under various fluid shear stresses and divert osmotic pressure gradients while imposing four different concentrations of an injected drug on cells. The multi-layer platform consisting of two bubble-trappers to eliminate all unwanted bubbles from the system, a concentration gradient generator to generate four different concentrations of the injected drug, and a membrane-based cell culture chamber caple of providing renal cells with their in-vivo condition. Using colorimetric techniques, the bubble trapper ability was quantified at flow rates up to...
Simulation of Cell and Particle Separation by Combination of Dielectrophoretic and Inertial Forces in a Microfluidic Device, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Ali Asghar
In this study, the dynamics of microparticles in a straight microchannel in the presence of an inhomogeneous oscillating electric field have been simulated by the immersed boundary method in combination with the lattice Boltzmann Navier-Stokes solver and the lattice Boltzmann method for solving the Poisson equation. The effect of the electric field on the location and number of particle equilibrium positions have been examined. In the absence of the electric field, circular particles will migrate to two stable equilibrium positions. The site of these equilibrium positions depends on the particle size and the fluid flow rate and is independent of the particle density. In the case of negative...
M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi
Today, microfluidics, representing the precise and controlled displacement of small amounts of fluid, is one of the most efficient tools available in various research fields, including medicine. Digital microfluidics is one of the newest microfluidic methods, which is based on the theory of electrowetting on dielectric. According to this theory, by applying a voltage difference to a droplet of fluid on a hydrophobic surface, the droplet can be moved on that surface. Therefore, by fabricating a plate containing a number of electrodes completely isolated from each other and controlling them, small droplets of fluid can be moved on a hydrophobic surface. In this thesis, the electrodes of this...
Experimental and Numerical Study of The Production of Alginate Microgels and Cancer Spheroids by Droplet-Based Microfluidic, M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir ; Kazemzadeh Hannani, Siamak
Significant advances in biotechnology have led to the emergence of a cost-effective way with less ethical issues to study disease, organ functions, tumors, and their response to drugs besides studying on animals. Microfluidic devices and organ on a chip (tumor on a chip) were introduced to remove those obstacles. Organ on a chip is a powerful tool for studying different types of tissues and simulating diseases, especially cancers, for biological and medical applications. Organ (tumor) on a chip is considered as a smaller scale of the real organ or tumor and it causes to the real-time study of tissues and their functions more accurately. In this study, to fabricate a droplet-based...