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micro-fluidic-devices
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Numerical modeling of surface reaction kinetics in electrokinetically actuated microfluidic devices
, Article Analytica Chimica Acta ; Vol. 838, issue , August , 2014 , pp. 64-75 ; ISSN: 00032670 ; Amini, Y ; Saidi, M. H ; Chakraborty, S ; Sharif University of Technology
Abstract
We outline a comprehensive numerical procedure for modeling of species transport and surface reaction kinetics in electrokinetically actuated microfluidic devices of rectangular cross section. Our results confirm the findings of previous simplified approaches that a concentration wave is created for sufficiently long microreactors. An analytical solution, developed for the wave propagation speed, shows that, when normalizing with the fluid mean velocity, it becomes a function of three parameters comprising the channel aspect ratio, the relative adsorption capacity, and the kinetic equilibrium constant. Our studies also reveal that the reactor geometry idealized as a slit, instead of a...
Microfluidic devices as invitro microenvironments for -stem cell culture
, Article Proceedings of the IASTED International Conference on Biomedical Engineering, BioMed 2014 ; 2014 , pp. 83-88 ; Abeddoust, M ; Mehboudi, N ; Sharif University of Technology
Abstract
Many potential therapies are currently being studied that may promote neural regeneration and guide regenerating axons to form correct connections following injury. It has been shown that adult neurons have some limited regenerative capabilities, and the lack of connection formation between neurons is not an intrinsic inability of these cells to form axons after being damaged, but rather the inhibitory microenvironment of the injured tissue prevents regeneration. In this study, the polarization and chemotaxis of neuronal stem cells (NSC) in response to quantified gradients of nerve growth factor (NGF) was examined. To accomplish this, a microfluidic device was designed and fabricated to...
Neuronal cell navigation within a microfluidic device
, Article Middle East Conference on Biomedical Engineering, MECBME ; 17-20 February , 2014 , pp. 261-264 ; Sharif University of Technology
Abstract
In this study, the polarization and navigation of neuronal cells was studied in response to quantified gradients of nerve growth factor (NGF). To accomplish this, a microfluidic device was designed and fabricated to generate stable concentration gradients of biomolecules in a cell culture chamber within a 3D microenvironment. Numerical simulation was implemented to optimize the device geometry for generating a uniform concentration gradient of NGF which was found to remain stable for multiple hours. Neural Stem/ Progenitor Cell (NSCs) migration and differentiation was studied within this microfluidic device in response to NGF concentration and within a 3D environment of collagen matrix....
Treatment of the small time instability in the finite element analysis of fluid structure interaction problems
, Article International Journal for Numerical Methods in Fluids ; Volume 71, Issue 6 , 2013 , Pages 756-771 ; 02712091 (ISSN) ; Movahhedy, M. R ; Sharif University of Technology
2013
Abstract
In this paper, the fluid-structure interaction problem in mechanical systems in which a high frequency vibrating solid structure interacts with the surrounding fluid flow is considered. Such a situation normally appears in many microelectromechanical systems like a wide variety of microfluidic devices. A different implementation of the residual-based variational multiscale flow method is employed within the arbitrary Lagrangian-Eulerian formulation. The combination of the variational multiscale method with appropriate stabilization parameters is used to handle the so-called small time step instability in the finite element analysis of the fluid part in the coupled fluid-structure interaction...
Parallel in-vitro and in-vivo techniques for optimizing cellular microenvironments by implementing biochemical, biomechanical and electromagnetic stimulations
, Article Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS ; 2012 , Pages 1397-1400 ; 1557170X (ISSN) ; 9781424441198 (ISBN) ; Heibatollahi, M ; Ghafar Zadeh, E
2012
Abstract
Development of novel engineering techniques that can promote new clinical treatments requires implementing multidisciplinary in-vitro and in-vivo approaches. In this study, we have implemented microfluidic devices and in-vivorat model to study the mechanism of neural stem cell migration and differentiation.These studies can result in the treatment of damages to the neuronal system. In this research, we have shown that by applying appropriate ranges of biochemical and biomechanical factors as well as by exposing the cells to electromagnetic fields, it is possible to improve viability, proliferation, directional migration and differentiation of neural stem cells. The results of this study can...
Pumping effect of bubble growth and collapse in microchannels: Thermo-hydraulic modeling
, Article Scientia Iranica ; Volume 19, Issue 3 , June , 2012 , Pages 431-436 ; 10263098 (ISSN) ; Saidi, M. H ; Sharif University of Technology
2012
Abstract
In the past two decades, microfluidic systems have become more appealing due to their wide applications in many areas, such as electronics, biotechnology, medicine, etc. Recently, the advantages of using the bubble growth phenomenon as a robust actuator in microfluidic devices have directed research interests towards the investigation of various applications. In this research, a new transient thermo-hydraulic model has been developed for bubble growth in confined volumes. The present model has been used to describe the pumping effect produced by the bubble growth and collapse phenomenon in microchannels. The results show relatively good agreement with experimental data. This study is useful...
A microfluidic device for 2D to 3D and 3D to 3D cell navigation
, Article Journal of Micromechanics and Microengineering ; Volume 26, Issue 1 , November , 2015 ; 09601317 (ISSN) ; Amirifar, L ; Sharif University of Technology
Institute of Physics Publishing
2015
Abstract
Microfluidic devices have received wide attention and shown great potential in the field of tissue engineering and regenerative medicine. Investigating cell response to various stimulations is much more accurate and comprehensive with the aid of microfluidic devices. In this study, we introduced a microfluidic device by which the matrix density as a mechanical property and the concentration profile of a biochemical factor as a chemical property could be altered. Our microfluidic device has a cell tank and a cell culture chamber to mimic both 2D to 3D and 3D to 3D migration of three types of cells. Fluid shear stress is negligible on the cells and a stable concentration gradient can be...
Integrative Utilization of Microenvironments, Biomaterials and Computational Techniques for Advanced Tissue Engineering
, Article Journal of Biotechnology ; Volume 212 , 2015 , Pages 71-89 ; 01681656 (ISSN) ; Mohammadaliha, N ; Mohseni, M ; Sharif University of Technology
Elsevier
2015
Abstract
This review aims to propose the integrative implementation of microfluidic devices, biomaterials, and computational methods that can lead to a significant progress in tissue engineering and regenerative medicine researches. Simultaneous implementation of multiple techniques can be very helpful in addressing biological processes. Providing controllable biochemical and biomechanical cues within artificial extracellular matrix similar to in vivo conditions is crucial in tissue engineering and regenerative medicine researches. Microfluidic devices provide precise spatial and temporal control over cell microenvironment. Moreover, generation of accurate and controllable spatial and temporal...
High throughput blood plasma separation using a passive PMMA microfluidic device
, Article Microsystem Technologies ; 2015 ; 09467076 (ISSN) ; Shamloo, A ; Mohammadaliha, N ; Hajghassem, H ; Mehrabadi, J. F ; Bazzaz, M ; Sharif University of Technology
Springer Verlag
2015
Abstract
Since plasma is rich in many biomarkers used in clinical diagnostic experiments, microscale blood plasma separation is a primitive step in most of microfluidic analytical chips. In this paper, a passive microfluidic device for on-chip blood plasma separation based on Zweifach–Fung effect and plasma skimming was designed and fabricated by hot embossing of microchannels on a PMMA substrate and thermal bonding process. Human blood was diluted in various times and injected into the device. The main novelty of the proposed microfluidic device is the design of diffuser-shaped daughter channels. Our results demonstrated that this design exerted a considerable positive influence on the separation...
High throughput blood plasma separation using a passive PMMA microfluidic device
, Article Microsystem Technologies ; Volume 22, Issue 10 , 2016 , Pages 2447-2454 ; 09467076 (ISSN) ; Shamloo, A ; Mohammadaliha, N ; Hajghassem, H ; Fallah Mehrabadi, J ; Bazzaz, M ; Sharif University of Technology
Springer Verlag
2016
Abstract
Since plasma is rich in many biomarkers used in clinical diagnostic experiments, microscale blood plasma separation is a primitive step in most of microfluidic analytical chips. In this paper, a passive microfluidic device for on-chip blood plasma separation based on Zweifach–Fung effect and plasma skimming was designed and fabricated by hot embossing of microchannels on a PMMA substrate and thermal bonding process. Human blood was diluted in various times and injected into the device. The main novelty of the proposed microfluidic device is the design of diffuser-shaped daughter channels. Our results demonstrated that this design exerted a considerable positive influence on the separation...
Efficient batch-mode mixing and flow patterns in a microfluidic centrifugal platform: a numerical and experimental study
, Article Microsystem Technologies ; 2016 , Pages 1-13 ; 09467076 (ISSN) ; Tirandazi, P ; Normandie, M ; Saidi, M. S ; Sharif University of Technology
Springer Verlag
Abstract
During recent years centrifugal-based microfluidic devices known as Lab-on-a-CD have attracted a lot of attentions. Applications of these CD-based platforms are ubiquitous in numerous biological analyses and chemical syntheses. Mixing of different species in microscale is one of the essential operations in biochemical applications where this seemingly simple task remains a major obstruction. Application of centrifugal force, however, may significantly improve the flow agitation and mixing, especially when it is combined with the Coriolis force which acts perpendicular to centrifugal force. In this study, mixing process in minichambers located on a rotating platform under a periodic...
Electrokinetic and aspect ratio effects on secondary flow of viscoelastic fluids in rectangular microchannels
, Article Microfluidics and Nanofluidics ; Volume 20, Issue 8 , 2016 ; 16134982 (ISSN) ; Saidi, M. H ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
Springer Verlag
2016
Abstract
The secondary flow of PTT fluids in rectangular cross-sectional plane of microchannels under combined effects of electroosmotic and pressure driving forces is the subject of the present study. Employing second-order central finite difference method in a very refined grid network, we investigate the effect of electrokinetic and geometric parameters on the pattern, strength and the average of the secondary flow. In this regard, we try to illustrate the deformations of recirculating vortices due to change in the dimensionless Debye–Hückel and zeta potential parameters as well as channel aspect ratio. We demonstrate that, in the presence of thick electric double layers, significant alteration...
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) ; Vatankhah, P ; Bijarchi, M. A ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
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...
A comparative study of collagen matrix density effect on endothelial sprout formation using experimental and computational approaches
, Article Annals of Biomedical Engineering ; Volume 44, Issue 4 , 2016 , Pages 929-941 ; 00906964 (ISSN) ; Mohammadaliha, N ; Heilshorn, S. C ; Bauer, A. L ; Sharif University of Technology
Abstract
A thorough understanding of determining factors in angiogenesis is a necessary step to control the development of new blood vessels. Extracellular matrix density is known to have a significant influence on cellular behaviors and consequently can regulate vessel formation. The utilization of experimental platforms in combination with numerical models can be a powerful method to explore the mechanisms of new capillary sprout formation. In this study, using an integrative method, the interplay between the matrix density and angiogenesis was investigated. Owing the fact that the extracellular matrix density is a global parameter that can affect other parameters such as pore size, stiffness,...
Polyamide/titania hollow nanofibers prepared by core–shell electrospinning as a microextractive phase in a fabricated sandwiched format microfluidic device
, Article Journal of Chromatography A ; Volume 1528 , 2017 , Pages 1-9 ; 00219673 (ISSN) ; Hashemi Hedeshi, M ; Bagheri, H ; Sharif University of Technology
Abstract
In this study, a low–cost microfluidic device from polymethyl methacrylate was fabricated by laser engraving technique. The device is consisted of a central chip unit with an aligned microchannel. Both sides of the engraved microchannel were sandwiched by two synthesized sheets from polyamide/titania (PA/TiO2) hollow nanofibers as extractive phases. The inlet and outlet of the device were connected to the polyether ether ketone tubes, while a peristaltic pump was used to deliver both sample and desorbing solvent through the microchannel. The recorded scanning electron microscopy images from the surface of the synthesized PA/TiO2 nanofibers, exhibit a good degree of homogeneity and porosity...
Carbon nanotubes in microfluidic lab-on-a-chip technology: current trends and future perspectives
, Article Microfluidics and Nanofluidics ; Volume 21, Issue 9 , 2017 ; 16134982 (ISSN) ; Amiri, H ; Zare, H ; Masroor, M ; Hasanzadeh, A ; Beyzavi, A ; Aref, A. R ; Karimi, M ; Hamblin, M. R ; Sharif University of Technology
Abstract
Advanced nanomaterials such as carbon nanotubes (CNTs) display unprecedented properties such as strength, electrical conductance, thermal stability, and intriguing optical properties. These properties of CNT allow construction of small microfluidic devices leading to miniaturization of analyses previously conducted on a laboratory bench. With dimensions of only millimeters to a few square centimeters, these devices are called lab-on-a-chip (LOC). A LOC device requires a multidisciplinary contribution from different fields and offers automation, portability, and high-throughput screening along with a significant reduction in reagent consumption. Today, CNT can play a vital role in many parts...
Efficient batch-mode mixing and flow patterns in a microfluidic centrifugal platform: a numerical and experimental study
, Article Microsystem Technologies ; Volume 23, Issue 7 , 2017 , Pages 2767-2779 ; 09467076 (ISSN) ; Tirandazi, P ; Normandie, M ; Saidi, M. S ; Sharif University of Technology
Abstract
During recent years centrifugal-based microfluidic devices known as Lab-on-a-CD have attracted a lot of attentions. Applications of these CD-based platforms are ubiquitous in numerous biological analyses and chemical syntheses. Mixing of different species in microscale is one of the essential operations in biochemical applications where this seemingly simple task remains a major obstruction. Application of centrifugal force, however, may significantly improve the flow agitation and mixing, especially when it is combined with the Coriolis force which acts perpendicular to centrifugal force. In this study, mixing process in minichambers located on a rotating platform under a periodic...
Parametric study on mixing process in an in-plane spiral micromixer utilizing chaotic advection
, Article Analytica Chimica Acta ; Volume 1022 , 2018 , Pages 96-105 ; 00032670 (ISSN) ; Shamloo, A ; Sharif University of Technology
Abstract
Recent advances in the field of microfabrication have made the application of high-throughput microfluidics feasible. Mixing which is an essential part of any miniaturized standalone system remains the key challenge. This paper proposes a geometrically simple micromixer for efficient mixing for high-throughput microfluidic devices. The proposed micromixer utilizes a curved microchannel (spiral microchannel) to induce chaotic advection and enhance the mixing process. It is shown that the spiral microchannel is more efficient in comparison to a straight microchannel, mixing wise. The pressure drop in the spiral microchannel is only slightly higher than that in the straight microchannel. It is...
Microfluidics-Enabled multimaterial maskless stereolithographic bioprinting
, Article Advanced Materials ; Volume 30, Issue 27 , 2018 ; 09359648 (ISSN) ; Nieto, D ; Iglesias, L ; Goodarzi Hosseinabadi, H ; Maharjan, S ; Ruiz Esparza, G. U ; Khoshakhlagh, P ; Manbachi, A ; Dokmeci, M. R ; Chen, S ; Shin, S. R ; Zhang, Y. S ; Khademhosseini, A ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
A stereolithography-based bioprinting platform for multimaterial fabrication of heterogeneous hydrogel constructs is presented. Dynamic patterning by a digital micromirror device, synchronized by a moving stage and a microfluidic device containing four on/off pneumatic valves, is used to create 3D constructs. The novel microfluidic device is capable of fast switching between different (cell-loaded) hydrogel bioinks, to achieve layer-by-layer multimaterial bioprinting. Compared to conventional stereolithography-based bioprinters, the system provides the unique advantage of multimaterial fabrication capability at high spatial resolution. To demonstrate the multimaterial capacity of this...
Design and simulation of a microfluidic device for acoustic cell separation
, Article Ultrasonics ; Volume 84 , March , 2018 , Pages 234-243 ; 0041624X (ISSN) ; Boodaghi, M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Experimental acoustic cell separation methods have been widely used to perform separation for different types of blood cells. However, numerical simulation of acoustic cell separation has not gained enough attention and needs further investigation since by using numerical methods, it is possible to optimize different parameters involved in the design of an acoustic device and calculate particle trajectories in a simple and low cost manner before spending time and effort for fabricating these devices. In this study, we present a comprehensive finite element-based simulation of acoustic separation of platelets, red blood cells and white blood cells, using standing surface acoustic waves...