scholarly journals Valveless Fluid Pumping via Zero-Net-Momentum Injection

2019 ◽  
Vol 15 (4) ◽  
pp. 55-60
Author(s):  
Johnathan Cace
Keyword(s):  
Flow Rate ◽  
Mechanical Method ◽  
Mass Source ◽  
Valveless Pumping ◽  
Potential Applications ◽  
Source And Sink

A novel mechanical method to valvelessly pump fluid has been developed using zero-net-momentum injection via a syringe and a tilted canister that function together as a periodic mass source and sink. Unlike previously discovered valveless pumping methods, this method does not require any elastic tubing and can be achieved by simple manual actuation, making it a simpler and less expensive valveless alternative. The flow rate is highly dependent on the frequency at which momentum is injected and retracted from the system. The direction of the flow can be changed by switching the location of the syringes. This pumping paradigm has potential applications in microfluidics where elastic channels are difficult to fabricate and valveless fluid actuation methods are preferred.

Performance and Development of a Miniature Rotary Shaft Pump

2005 ◽  
Vol 127 (4) ◽  
pp. 752-760 ◽  
Author(s):  
Danny Blanchard ◽  
Phil Ligrani ◽  
Bruce Gale
Keyword(s):  
Flow Rate ◽  
Pressure Rise ◽  
Electronics Cooling ◽  
Maximum Flow ◽  
Operating Conditions ◽  
Working Fluid ◽  
Hydraulic Efficiency ◽  
Potential Applications ◽  
Total Analysis ◽  
And Performance

The development and performance of a novel miniature pump called the rotary shaft pump (RSP) is described. The impeller is made by boring a 1.168 mm hole in one end of a 2.38 mm dia shaft and cutting slots in the side of the shaft at the bottom of the bored hole such that the metal between the slots defines the impeller blades. The impeller blades and slots are 0.38 mm tall. Several impeller designs are tested over a range of operating conditions. Pump performance characteristics, including pressure rise, hydraulic efficiency, slip factor, and flow rate, are presented for several different pump configurations, with maximum flow rate and pressure rise of 64.9ml∕min and 2.1 kPa, respectively, when the working fluid is water. Potential applications include transport of biomedical fluids, drug delivery, total analysis systems, and electronics cooling.

Net flow generation in closed-loop valveless pumping

2020 ◽  
Vol 234 (11) ◽  
pp. 2126-2142 ◽  
Author(s):  
Christos Manopoulos ◽  
Sokrates Tsangaris ◽  
Dimitrios Mathioulakis
Keyword(s):  
Flow Rate ◽  
Closed Loop ◽  
Simultaneous Recording ◽  
Elastic Tube ◽  
Fluid Medium ◽  
Flexible Tube ◽  
Flow Generation ◽  
Valveless Pumping ◽  
Valveless Pump ◽  
Flexible Walls

Net flow generation in valveless pumping, met in many physiological applications and recently in micropumping devices, constitutes an open fluid dynamics issue due to the complex interaction between the fluid medium and the flexible walls of the pump. In the context of the present experimental work, the conditions of the net flow generation are examined in a closed-loop horizontal valveless pump, which consists of a rigid and an elastic tube of equal diameters and lengths, and a pincher that forces the liquid within the tube to oscillate at Reynolds and Womersley numbers up to 7800 and 48, respectively. Pinching off as well as at the mid-length of the pump flexible tube, net flow is generated at certain pinching frequencies for which details are presented based on simultaneous recording of the pressure at the two tube junctions, the flow rate and the displacement of the pincher. Pinching off the mid-length of the pump at low pinching frequencies, net flow rate is practically null due to the almost identical pressure waveforms at the tube junctions, which vary in phase with the pincher motion. However, close to the first natural frequency of the hydraulic loop, the reflection of the pressure waves at the tube junctions combined with their increased phase difference cause high axial pressure gradients, which when they increase simultaneously with the squeezing of the tube, net flow rate maximization occurs. Pinching at the flexible tube mid-length area, nonzero net flow rates can also be generated, the sign of which changes when the pincher mid-point crosses the tube mid-length without being nullified.

scholarly journals Synthesis of Nanoscale Liposomes via Low-Cost Microfluidic Systems

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1050
Author(s):  
Andres Aranguren ◽  
Carlos E. Torres ◽  
Carolina Muñoz-Camargo ◽  
Johann F. Osma ◽  
Juan C. Cruz
Keyword(s):  
Flow Rate ◽  
Colloidal Stability ◽  
Low Cost ◽  
Continuous Phase ◽  
Flow Rate Ratio ◽  
Synthesis Methods ◽  
Microfluidic Systems ◽  
Uniform Size ◽  
Pmma Sheet ◽  
Potential Applications

We describe the manufacture of low-cost microfluidic systems to produce nanoscale liposomes with highly uniform size distributions (i.e., low polydispersity indexes (PDI)) and acceptable colloidal stability. This was achieved by exploiting a Y-junction device followed by a serpentine micromixer geometry to facilitate the diffusion between the mixing phases (i.e., continuous and dispersed) via advective processes. Two different geometries were studied. In the first one, the microchannels were engraved with a laser cutting machine on a polymethyl methacrylate (PMMA) sheet and covered with another PMMA sheet to form a two-layer device. In the second one, microchannels were not engraved but through-hole cut on a PMMA sheet and encased by a top and a bottom PMMA sheet to form a three-layer device. The devices were tested out by putting in contact lipids dissolved in alcohol as the dispersed phase and water as the continuous phase to self-assemble the liposomes. By fixing the total flow rate (TFR) and varying the flow rate ratio (FRR), we obtained most liposomes with average hydrodynamic diameters ranging from 188 ± 61 to 1312 ± 373 nm and 0.30 ± 0.09 PDI values. Such liposomes were obtained by changing the FRR from 5:1 to 2:1. Our results approached those obtained by conventional bulk synthesis methods such as a thin hydration bilayer and freeze-thaw, which produced liposomes with diameters ranging from 200 ± 38 to 250 ± 38 nm and 0.30 ± 0.05 PDI values. The produced liposomes might find several potential applications in the biomedical field, particularly in encapsulation and drug delivery.

Study of Submerged Jet for Suction of Fluid

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Sudhakar Subudhi ◽  
K. R. Sreenivas ◽  
Jaywant H. Arakeri
Keyword(s):  
Flow Rate ◽  
Coming Out ◽  
Particle Image ◽  
Lateral Separation ◽  
Flow Rates ◽  
Submerged Jet ◽  
Image Velocimetry ◽  
Suction Flow ◽  
Source And Sink

This paper deals with the study of a submerged jet for the suction of unwanted fluid. This submerged jet is caused by the fluid coming out from a source. The presence of a sink in front of this source facilitates the suction of the fluid depending upon the source and sink flow rates, the axial and lateral separations of the source and sink, and the angle between the axes of the source and sink. The main purpose is the determination of the sink flow rate for 100% removal of the source fluid as a function of these parameters. The experiments have been carried using a source nozzle 6 mm in diameter and two sizes for the sink pipe diameter: 10 mm and 20 mm. The main diagnostics used are flow visualization using dye and particle image velocimetry (PIV). The dependence of the required suction flow rate to obtain 100% effectiveness on the suction tube diameter and angle is relatively weak compared to the lateral separation.

Performance and Development of a Miniature Rotary Shaft Pump (RSP)

2004 ◽  
Author(s):  
Daniel B. Blanchard ◽  
Phillip M. Ligrani ◽  
Bruce K. Gale
Keyword(s):  
Flow Rate ◽  
Pressure Rise ◽  
Electronics Cooling ◽  
Maximum Flow ◽  
Operating Conditions ◽  
Working Fluid ◽  
Pump Performance ◽  
Potential Applications ◽  
Total Analysis ◽  
And Performance

The development and performance of a novel miniature pump called the rotary shaft pump (RSP) is described. The impeller is made by boring a hole in one end of a shaft, and cutting slots in the side of the shaft at the bottom of the bored hole, such that the metal between the slots defines the impeller blades. Several impeller designs are tested over a range of operating conditions. Pump performance characteristics, including pressure rise, efficiency, slip factor, and flow rate are presented for several different pump configurations, with maximum flow rate and pressure rise of 64.9ml/min, and 2.1kPa, respectively, when the working fluid is water. Potential applications include transport of biomedical fluids, drug delivery, total analysis systems, and electronics cooling.

Dynamic Liquid Optical Splitters and Interferometers Integrated into Micro-Fluidic-Systems

2009 ◽  
Vol 74 ◽  
pp. 67-70
Author(s):  
Yi Yang ◽  
Ai Qun Liu
Keyword(s):  
Diffusion Coefficient ◽  
Flow Rate ◽  
Early Stage ◽  
Optical Devices ◽  
Optical Switches ◽  
Single Source ◽  
Flow Rates ◽  
Stage Of Development ◽  
Depth Analysis ◽  
Potential Applications

As the field of Micro-Fluidic-Systems (MFS) is still at it early stage of development, only some simple optical devices such as liquid waveguide and liquid optical switches have been reported. The lack of in-depth analysis makes some novel photonic phenomena unexplained and uninvestigated in MFS. Solutions to these problems require a lot of imagination and ingenuity. In this paper, dynamic liquid optical splitters and interferometers have been demonstrated by diffusion according to flow rates are reported. In the case of the Y splitters, light from a single source can be split into two directions with angle-controlled dynamic. To the interferometers, light from a single source can be split and then combined to interference. The lengths of the interferometers can be controlled from via control of diffusion coefficient and flow rate. It implies that the Micro-Photonic-Fluidic –Systems may establish a new branches to MFS and has potential applications in biological, chemical and medical solution detectors.

scholarly journals Optimizing the Microstructure, Mechanical, and Tribological Properties of Si-DLC Coatings on NBR Rubber for Its Potential Applications

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 671
Author(s):  
Guangqiao Liu ◽  
Zedong Wen ◽  
Kui Chen ◽  
Limei Dong ◽  
Zhenlu Wang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Flow Rate ◽  
Friction And Wear ◽  
High Strength ◽  
Butadiene Rubber ◽  
Mechanical And Tribological Properties ◽  
Deposition Parameters ◽  
Potential Applications ◽  
Si Content

Si doped diamond-like carbon (Si-DLC) films were deposited on nitrile-butadiene rubber (NBR), and the effects of deposition parameters on the mechanical and tribological properties of an Si-DLC top layer on NBR were investigated. Then, the sample with the best performance is selected to investigate its tribological behaviors and mechanism under different contact loads. The results show that the growth rate and the doped Si content are also decreased with increasing the CH4 flow rate. The Si atom exists in the form of Si-C bonds at low CH4 flow rate (≤40 sccm) and Si-C + Si-O-C bonds at high CH4 flow rate (≥60 sccm). Furthermore, the sp3 content increases monotonously, while the hardness and H3/E2 ratio firstly decreases and then increases. As a result, the friction and wear behaviors are in line with the change trend of the hardness. The lowest friction coefficient (~0.19) and a slight wear were achieved for the Si-DLC3 film under the relatively high load of 3 N. The tribological results indicate that the friction coefficient and wear increase monotonously with the increase of load, which is mainly attributed to the brittle fragmentation of films at a higher load, and thus a high strength and super toughness DLC films should be needed. Furthermore, the friction and wear behaviors of samples depend critically on its surface topography, and the wear is lower when the friction direction is parallel to the stripes.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

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