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    Experimental Study of Movement of Mercury Droplets in Micro Channel by Electromagnetic Force

    , M.Sc. Thesis Sharif University of Technology Ardeshir Larijani, Morteza (Author) ; Afshin, Hossein (Supervisor)
    Abstract
    As today's tremendous advance occurred in biotechnology and nanotechnology, the microfluidic devices made a new success that was not possible with the traditional equipments. It was useful in such a way that by using a microliter volume of that fluid, we could have the ability to use it in biologics, medicine, aerospace, cooling electronic systems and medical discovery. One of the main component of fluidic microsystems are micropumps in which they divide into two types. Reciprocating micropumps have been worked by stimulating electromagnetic micropumps which is based on Lorentz law. In this project, we try to investigate the impact of effective parameters in the movement of the mercury mass.... 

    Design and Fabrication of a Novel Mercury Micropump Actuated Electeromagneticaly

    , M.Sc. Thesis Sharif University of Technology Karmozdi, Mohsen (Author) ; Shafii, Mohammad Behshad (Supervisor)
    Abstract
    Considering the advantages and disadvantages of reported micropumps, we aimed to introduce a novel idea to diminish the disadvantages and promote the advantages of PiezoElectric micropumps. This novel idea operates based on a mercury slug actuation in a microchannel. This cyclic motion of the mercury slug which is similar to a piston, push the fluid in the microchannel and pump the flow. However, to bring this idea into the practice, a control system must be designed. This system contains: LABVIEW code, DAQ board & a switching Board. The pattern of actuating mercury is drawn in LABVIEW. DAQ Board produces electrical signals according to LABVIEW code. Switching board will transform the... 

    Numerical study on the performance of Tesla type microvalve in a valveless micropump in the range of low frequencies

    , Article Journal of Micro-Bio Robotics ; Volume 8, Issue 3 , 2013 , pp 145-159 ; 21946418 (ISSN) Mohammadzadeh, K ; Kolahdouz, E. M ; Shirani, E ; Shafii, M. B ; Sharif University of Technology
    Abstract
    In this study, the performance of Tesla-type microvalves, used in micropumps for low frequency driving force, is examined. Three-dimensional and unsteady numerical analysis of fluid flow inside a valveless reciprocating micropump in the range of low working frequencies is carried out. Reciprocating movement of flow actuator provides the actuation and pumping of the working fluid. Ferrofluidic valveless micropump is one practical sample of this kind of micropumps that operate in the range of low working frequencies. To model the reciprocating movement of flow actuator, two time varying functions that includes sinusoidal and step excitation are employed. Also, the performance of... 

    Numerical optimization of three-cavity magneto mercury reciprocating (MMR) micropump

    , Article Engineering Applications of Computational Fluid Mechanics ; Volume 15, Issue 1 , 2021 , Pages 1954-1966 ; 19942060 (ISSN) Mehrabi, A ; Mofakham, A. A ; Shafii, M. B ; Sharif University of Technology
    Taylor and Francis Ltd  2021
    Abstract
    The operation of the three-cavity magneto mercury reciprocating (MMR) micropump, whose prototype were presented in an earlier companion paper, was numerically explored. In the three-cavity MMR micropump, three mercury slugs are moved by a periodic Lorentz force with a phase difference in three separate cavities. A consecutive motion of the slugs in their cavities transfer air from the inlet to the outlet. Two-dimensional OpenFOAM simulations were carried out to explore the influence of electric current excitation phase difference and back-pressure. The numerical simulations predicted the MMR micropump (with no valve) with a phase difference of (Formula presented.) and (Formula presented.)... 

    A new model for dynamic analysis of side mounted diffuser valve micropumps

    , Article 8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006, Torino, 4 July 2006 through 7 July 2006 ; Volume 2006 , 2006 ; 0791837793 (ISBN); 9780791837795 (ISBN) Ahmadian, M. T ; Mehrabian, A ; Sharif University of Technology
    American Society of Mechanical Engineers  2006
    Abstract
    Valveless micropumps are widely used due to simple structure, durability and low maintenance. Understanding the fluid-membrane interaction and performance criteria is still a challenging problem for the scientists. In this work, a new model for side mounted valve micropumps is developed to obtain dynamic response of micropump with respect to piezoelectric actuation. The parameters of this model are obtained in terms of actuation frequency and geometrical dimensions of the micropump. Balancing elastic, inertial and damping forces result in the governing equation of the micropump system model. Analytical studies for the bottom mounted valve micropump indicate pump flux is independent of the... 

    Design and Fabrication of a Ferrofluidic Miniature Pump

    , Ph.D. Dissertation Sharif University of Technology Ashouri, Majid (Author) ; Shafii, Mohammad Behshad (Supervisor) ; Moosavi, Ali (Supervisor)
    Abstract
    This thesis presents the prototype design and fabrication of magnetically actuated miniature pumps which utilize self-sealing capability of ferrofluid-covered permanent magnets in both pumping and valving mechanisms. The contactless external actuation feature of the design enables integration of the pump with other PMMA-based microfluidic systems with low cost and disposability. The body of the 1st fabricated prototype pump consists of three nozzle/diffuser elements and two pumping chambers connected to the ends of a flat-wall pumping cylinder. A cylindrical permanent magnet placed inside the pumping cylinder acts as a piston which reciprocates by using an external magnetic actuator driven... 

    The effect of droplet size, channel length and the amount of electromagnetic actuation force on reciprocating movement of mercury droplets in the magneto mercury reciprocating (MMR) micropumps

    , Article Sensors and Actuators, A: Physical ; Volume 283 , 2018 , Pages 204-210 ; 09244247 (ISSN) Karmozdi, M ; Shafii, M. B ; Afshin, H ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Micropumps are regarded as one of the devices used in microsystems, which are responsible for pumping working fluid. The magnetic reciprocating micropump is an example of the existing micropumps in which the pumping agent includes three liquid metal droplets placed inside lateral channels and reciprocated by the electromagnetic force inside their channels. The working fluid located inside the main channel is pumped through due to the movement of these three droplets. The time duration in which the droplet traverses the sub-channel length is crucial in the operation of the suggested micropump. The present study aims to evaluate the effect of the length of sub-channels, moving droplet volume... 

    Experimental and analytical modeling of phase change micropump

    , Article 8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006, Torino, 4 July 2006 through 7 July 2006 ; Volume 2006 , 2006 ; 0791837793 (ISBN); 9780791837795 (ISBN) Saidi, M. H ; Safaei, H ; Sadjadi, B ; Pirouzpanah, S ; Sharif University of Technology
    2006
    Abstract
    In this research a phase change micropump as a novel type of non-mechanical micropumps has been investigated. A one dimensional model has been developed to describe the pumping mechanism and assess the working characteristics of the micropump. Conservation of mass, momentum and energy have been employed to obtain an algebraic equation for the flow rate which depends on seven non-dimensional numbers. The governing equation has been solved to study the effect of various operating parameters on the micropump performance. To verify the analytical approach, an experimental set up has been constructed. The results show that the theoretical model is in reasonable agreement with the experimental... 

    Fabrication and Theoretical Investigation of a Single Bubble Nozzle-Diffuser Micropump

    , M.Sc. Thesis Sharif University of Technology Pirouzpanah, Sahand (Author) ; Saeedi, Mohammad Hassan (Supervisor) ; Saeedi, Mohammad Saeed (Supervisor)
    Abstract
    The potential of phase change process in liquids at microscale has been a favorite for the scientists to fabricate this type of micropumps. To hold unidirectional flow in microchannels usually nozzle-diffuser arrangement is used. Due to the existence of difference in pressure drop in the nozzle and diffuser sections, one can see unidirectional flow through diffuser direction. The objective of this article is to analyze analytically the thermo-hydrodynamic behavior of the Isopropyl Alcohol (IPA) bubble of a phase change micropump. Considering the simultaneous effects of hydrodynamic and thermal characteristics of the bubble in the bubble generation chamber, and temperature-saturation... 

    Fabrication of Ferrofluidic Micropump

    , M.Sc. Thesis Sharif University of Technology Ashouri, Majid (Author) ; Shafii, Mohammad Behshad (Supervisor) ; Saidi, Mohammad Said (Supervisor) ; Saidi, Mohammad Hassan (Supervisor)
    Abstract
    In this project, two Ferrofluidic micropumps that do not need any mechanical moving parts are presented. These micropumps are including simple microchannels containing magnetic fluid plugs that are used as flow actuator and the on/off valve. Using external magnetic field actuation in this type of micropumps, the magnetic fluid would have continuous motion in a channel with micrometer dimensions that would provide the main fluid to be pumped. Although the plug of magnetic fluid has surface contact with operative fluid, but considering its specific features, it would not compine with the pumping fluid. These micropumps may be used to pump the fluids or gases. The outcomes of the investigation... 

    Numerical Simulation of Magneto Mercury Reciprocating Micropump

    , M.Sc. Thesis Sharif University of Technology Mehrabi, Ali (Author) ; Shafii, Mohammad Behshad (Supervisor)
    Abstract
    In this investigation Magneto Mercury Reciprocating Micrpump (MMRM) the combination of Magneto-Hydrodynamic and Reciprocating micropumps has been analyzed. To achieve the analytical and numerical solution of one-tank and three-tank MMRM, the momentum, continuity, volume fraction and magnetohydrodynamic equations have been presented. The dimensionless analytical solution of one-phase and two-phase three dimensional MHD flow in the condition of using constant current and potential electrical source, has been offered.
    The boundary between mercury and air has been tracked via VOF method in OpenFOAM software. VOF equation has been solved by explicit method with variable time step and maximum... 

    Design and Fabrication of Reciprocating Micropumps with Actuated Fluid Slug

    , M.Sc. Thesis Sharif University of Technology Amiri Hezave, Hamid (Author) ; Shafii, Mohammad Behshad (Supervisor)
    Abstract
    Design, fabrication and performance of the reciprocating micropumps with actuated fluid slug have been investigated. In these micropumps, pumping principle is based on reciprocating movement of a fluid slug. The fluid slug must be conductive in magnetohydrodaynamic micropump to be actuated by Lorentz force and have good magnetic properties in ferrofluidic micropumps to be actuated by an external magnetic field.
    On the other hand, a theory is developed in ahead of design and fabrication process to diagnose the critical and the most influential parameters. Magnetohydrodynamic micropumps in 4 distinict design using nozzle-diffuser element, passive ball valve and active mercury valve have... 

    Performance of valveless diffuser micropumps under harmonic piezoelectric actuation

    , Article 8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006, Torino, 4 July 2006 through 7 July 2006 ; Volume 2006 , 2006 ; 0791837793 (ISBN); 9780791837795 (ISBN) Ahmadian, M. T ; Saidi, M. H ; Mehrabian, A ; Bazargan, M ; Kenarsari, S. D ; Sharif University of Technology
    American Society of Mechanical Engineers  2006
    Abstract
    Valveless piezoelectric micropumps are in wide practical use due to their ability to conduct particles with absence of interior moving mechanical parts. The objective of this paper is to obtain the fluid flow response to actuation frequency of a passive diffuser valve under harmonic pressures. In this regards a 2D model of a micropump valves and chambers is analyzed. The analysis is performed for 10Kpa back pressure on micropump chamber and actuation frequencies within the range of 1Hz to 10 KHz. Results show the highest velocity in the direction of diffuser axis occurs at the narrow diffuser neck while flow direction reverses every half period. For low frequencies, a parabolic velocity... 

    Propose and characteristics study of a new actuation method for micropumps, using membrane buckling

    , Article 4th ASME Integrated Nanosystems Conference: Design, Synthesis, and Applications, Berkeley, CA, 14 September 2005 through 16 September 2005 ; 2005 , Pages 25-26 ; 0791842088 (ISBN); 9780791842089 (ISBN) Saghafi, M. H ; Ahmadian, M. T ; Salehi, H ; Monazami, R ; Zade, A. Q ; Sharif University of Technology
    American Society of Mechanical Engineers  2005
    Abstract
    In this paper, we present a novel idea on actuation system in micropumps. The prominent goal of this paper is to propose and prove a mechanical actuation system which works in high frequency and has good ability in producing flow and pressure in micro actuation system. As like as other common micropumps, the proposed scheme is consisted of two check valves and an actuation space. The actuation space includes a volume of liquid in a chamber and a cylindrical membrane as the actuator. The main aspect of this idea is employment of buckling as a consequence of incensement of its internal pressure caused by temperature rising in the membrane. Rise of temperature is done by passing a controllable... 

    Modeling of a Thermopneumatic Micropump

    , M.Sc. Thesis Sharif University of Technology Shahsavari, Setareh (Author) ; Saeedi, Mohammad Hassan (Supervisor) ; Saeedi, Mohammad Saeed (Supervisor) ; Shafii, Mohammad Behshad (Supervisor)
    Abstract
    Thermopneumatic micropump is one type of positive displacement micropumps, which has many applications due to its relatively large stroke volume, low working voltage, and simple fabrication in microscale. In this paper, a numerical study of heat transfer and fluid flow in a valveless thermopneumatically driven micropump is presented. For rectifying the bidirectional flow, a nozzle and a diffuser are used as the inlet and outlet of the chamber. Since the fluid flow is induced by the motion of a diaphragm, the numerical simulation includes fluid structure interaction, which requires applying a dynamic mesh. The domain of solution is divided into two sections; the actuator unit, which contains... 

    Fabrication and Experimental Investigation of Rotary Agnetohydrodynamic Micropump

    , M.Sc. Thesis Sharif University of Technology Esmaily Moghaddam, Mahdi (Author) ; Behshad Shafii, Mohammad (Supervisor)
    Abstract
    Considering the advantages and disadvantages of reported micropumps, we aimed to introduce a novel idea to diminish the disadvantages and promote the advantages of Magnetohydrodynamic (MHD) micropumps. This novel idea operates based on a mercury slug rotation in a circular microchannel. This cyclic motion of the mercury slug which is similar to a piston, push the fluid in the microchannel and pump the flow. However, to bring this idea into the practice, it must be integrated with a specific valve. Fluid has not to go through this specific valve. In contrary, mercury slug has to pass across this valve. These two specifications must be considered during the design process of the valve. On the... 

    Numerical Simulation of Rotary Magnetohydrodynamic Micropump

    , M.Sc. Thesis Sharif University of Technology Abdollahi Mofakham, Amir (Author) ; Shafii, Mohammad Behshad (Supervisor)
    Abstract
    First by reviewing some built micropumps, the importance of rotary magnetohydrodynamic micropump has been highlighted. Then some information about the performance and rules applied to these specific micropumps has been provided. Based on the research, the necessity of using transient flow relations for analyzing the procedure of these micropumps would become crucial. The next step would be extracting the information out of dimensionlessrelations of magnetohydrodynamic theory and dimension less equations of momentum in transientsingle-phase fluid flow which is moved by theoverall Lorentzforce in between 2 parallel surfaces. It would be done in two state of using constantcurrent source and... 

    Design and Simulation of an Electrowetting Micro-Pump

    , M.Sc. Thesis Sharif University of Technology Ebrahimi, Amin (Author) ; Javadi, Khodayar (Supervisor)
    Abstract
    Micropumps are one of the most important devices in the field of microfluidics which have many applications in various fields of engineering. Electrostatic excitation is one of the types of excitation mechanisms in micropumps that is widely used in microelectromechanical systems due to its low power consumption and easier control. In this research, first, the physics of droplets on the surface studied, important dimensionless numbers and other factors influencing microfluidic phenomena are investigated. The effective parameters of the droplet motion and the mechanism of this motion are described. Besides, the phenomenon of electrowetting, one of the phenomena in the field of dynamics of... 

    Experimental study of a novel Magneto Mercury Reciprocating (MMR) micropump, fabrication and operation

    , Article Sensors and Actuators, A: Physical ; Volume 194 , 2013 , Pages 277-284 ; 09244247 (ISSN) Karmozdi, M ; Salari, A ; Shafii, M. B ; Sharif University of Technology
    2013
    Abstract
    Today, MEMS have wide applications in modern technologies. Magneto hydro dynamic (MHD) micropumps play an important role in the MEMS industry and have been thoroughly studied in the recent years. In this study, the idea of classic reciprocating micropumps was combined with magneto hydro dynamics (MHD) to develop a novel Magneto Mercury Reciprocating (MMR) micropump. To attain this goal, the Lorentz force, as the actuation mechanism, was used to move a conductive liquid (mercury) slug in a reciprocating manner in order to suck the working fluid (air) from the inlet and pump it to the outlet. The performance of the fabricated MMR micropump was examined in terms of parameters such as pressure... 

    Numerical investigation on the effect of the size and number of stages on the tesla microvalve efficiency

    , Article Journal of Mechanics ; Volume 29, Issue 3 , 2012 , Pages 527-534 ; 17277191 (ISSN) Mohammadzadeh, K ; Kolahdouz, E. M ; Shirani, E ; Shafii, M. B ; Sharif University of Technology
    2012
    Abstract
    In the present study, the effect of the number of stages of Tesla Micro-Valve (TMV), as well as the dependency of Reynolds number, Re, on the valve performance has been analyzed. For this purpose, different layouts include one to four-stage with different sizes are investigated numerically. The main criterion for evaluation of valves performance is diodicity, Di. Unsteady and steady flow in valve have been simulated and compared. It is shown that although there are some difference but the trend is similar for both responses. Finally, 2-D and steady state computations of the fluid flow have been utilized that reveal a strong dependence of Di on Re and pressure drop, ΔP. The results showed...