A New Monolithic Electrokinetic Pump With Bubble-Less Design

2005 ◽  
Author(s):  
Ping Wang ◽  
Zilin Chen ◽  
Hsueh-Chia Chang
Keyword(s):  
Flow Rate ◽  
Sol Gel ◽  
Maximum Flow ◽  
Liquid Solution ◽  
Fused Silica ◽  
Silica Matrix ◽  
Maximum Pressure ◽  
Micro Pump ◽  
Micro Total Analysis Systems ◽  
Fused Silica Capillary

An electrokinetic micro-pump fabricated by a sol-gel process has been designed which can be used as a robust fluid-driving unit on a chip-scale analytical system. An overall monolithic silica matrix with morphology of micron-scaled through pores was formed within 100-μm inner diameter fused silica capillary. This pump utilizes electroosmotic flow to propel liquid solution with no moving parts. The Nafion® house design in the cathode chamber separates the electrolytic bubble interference from flow channels. The maximum flow rate and maximum pressure generated by the pump are 3.0 μL/min and 3.5 atm, respectively, at 6 kV. The flow rate can be controlled in the range 200 nL-3.0 μL/min by adjusting applied electric filed. As the monolith is silica-based, this pump can be used for a variety of fluids, especially for organic solvents such as acetonitrile and methanol, without swelling and shrinking problems. These results indicate that the pump can provide sufficient pressure and flow for micro-total-analysis systems (μTAS).

Design and Analysis of a Thin Film Permanent Magnet Actuated Micro Pump

2013 ◽  
Vol 7 (2) ◽  
pp. 196-204 ◽  
Author(s):  
Chao Zhi ◽  
◽  
Tadahiko Shinshi ◽  
Minoru Uehara ◽  
Keyword(s):  
Thin Film ◽  
Permanent Magnet ◽  
Flow Rate ◽  
Maximum Flow ◽  
High Flow ◽  
Deformation Analysis ◽  
Maximum Pressure ◽  
Large Deformation Analysis ◽  
Micro Pump ◽  
Displacement Measurements

In this paper we present the design, analysis and an experimental evaluation of a micro pump utilizing a 20 µm thick, 3 mm diameter Thin Film Permanent Magnet (TFPM). The pump includes an electromagnet that uses a magnetic closed circuit. The design of the electromagnet was optimized and was theoretically explained. A PolyDiMethylSiloxane (PDMS) diaphragm with a thickness of approximately 80 µm was used in the pump. The electromagnetic force on the diaphragmwas calculated using a finite elementmethod. Large deformation analysis was used to calculate the displacement of the diaphragm. The force and displacement measurements agreed well with those calculated by simulation. The performance of the fabricated pump was also evaluated. During pumping, the displacement of the diaphragm reached 500 µm, which is the same as the height of the chamber. Furthermore, because of the large displacement, the pump is bubble tolerant and self-priming. A maximum flow rate of 50 µL/min and a maximum pressure of 110 Pa were achieved. A square wave input signal was demonstrated to be more effective than a sinusoidal signal in generating a high flow rate.

Development of a Mini Liquid Cooling System for High Heat Flux Electronic Devices

2009 ◽  
Author(s):  
Chien-Yuh Yang ◽  
Chun-Ta Yeh ◽  
Kou-Chung Huang ◽  
Shao-Nong Tsai
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Maximum Flow ◽  
Maximum Pressure ◽  
High Heat Flux ◽  
Cold Plate ◽  
Liquid Cooling ◽  
Commercial Products ◽  
Micro Pump ◽  
Liquid Cooling System

The size of the most of the current commercialized liquid cooling systems is apparently too large to be easily adapted in a notebook or a mini size desk top computer. This study incorporated the authors’ previous micro heat exchanger design with an extra slim pump concept proposed by a local manufacturer to develop a high performance miniature liquid cooling system. An integrated pump and cold plate assembly was also developed for further reducing the overall size of the system. In comparing to the commercial products, the test results show that the micro pump provides a higher maximum pressure head and maximum flow rate performance. The cold plate has the lowest thermal resistance at moderate and high flow rate region. And the performed of the entire liquid system is similar to that of the recently announced product. It is emphasized that the size of the present developed cold plate, pump and liquid cooling system is much smaller than that of all commercial products.

Valveless Micropump with Saw-Tooth Microchannel

2014 ◽  
Vol 613 ◽  
pp. 228-235 ◽  
Author(s):  
Ying Hua Xu ◽  
Wei Ping Yan ◽  
Li Guo
Keyword(s):  
Flow Rate ◽  
Maximum Flow ◽  
Width Ratio ◽  
Driving Voltage ◽  
Tooth Structure ◽  
Valveless Micropump ◽  
Micro Pump ◽  
Pump Flow Rate ◽  
Mems Technology ◽  
Micro Total Analysis Systems

The micropump is the executive component in a microfluidic chip which impels the sample to flow. Its performance directly affects the precision and reliability of Micro Total Analysis Systems (μTAS), and it also plays a key role in the targeting transport of trace substances. The single and double chamber valveless micropumps with saw-tooth microchannel were designed. The saw-tooth diffuser/nozzle pipe was fabricated on chrome glass substrate using MEMS technology and the pump diaphragm was manufactured by PMMA material. The piezoelectric bimorph with cantilever beam was adopted as driving pump actuator and PDMS material as pump diaphragm. The valveless micropumps for both single and double chambers were formed with different saw-tooth structure parameters. The flow rate increased about 25% when the sidewall of microchannel changed from smooth to saw-tooth, and with the driving voltage increasing, the positive and negative flow difference of saw-tooth diffuser/nozzle pipe increased significantly, so does the micro pump flow rate. The best diffused angle θ was determined by the microchannel length L of saw-tooth diffuser/nozzle pipe, and the micro pump operated with its maximum flow rate only when the length-width ratio A reached the best value. The flow rate of a saw-tooth diffuser/nozzle valveless micropump with parallel double chambers increased approximately 30% than that of a single chamber.

Directional Pumping Performance of an Electrostatic Checkerboard Microvalve

2006 ◽  
Author(s):  
Hanseup Kim ◽  
Aaron A. Astle ◽  
Luis P. Bernal ◽  
Khalil Najafi ◽  
Peter D. Washabaugh
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Maximum Flow ◽  
Pressure Differential ◽  
Oscillatory Motion ◽  
Sinusoidal Signal ◽  
Maximum Pressure ◽  
Experimental Characterization ◽  
Gas Pumping

This paper reports experimental characterization of directional gas pumping generated by MEMS-fabricated checkerboard-type electrostatic microvalves. It is found that the oscillatory motion of the checkerboard microvalve membrane provides both the pumping and valve functions of a pump, namely: 1) to cause the volume displacement and, thus, compression and transfer of gas, and 2) to direct gas flow in one direction by closing and opening air paths in the proper sequence. Here, we describe the microvalve-only design, and report the pumping performance producing a maximum flow rate of 1.8 sccm and a maximum pressure differential of 3.0 kPa for five microvalves driven simultaneously with a sinusoidal signal of ± 100V amplitude at 5.5 kHz.

Effect of shielding gas flow rate on arc behaviors in GMAW with single cable-typed wire

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040059
Author(s):  
Qingxian Hu ◽  
Lei Zhang ◽  
Juan Pu ◽  
Caichen Zhu
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Maximum Flow ◽  
Maximum Pressure ◽  
Arc Plasma ◽  
Shielding Gas ◽  
Gas Flow Rate

A three-dimensional numerical model of arc in gas metal arc welding (GMAW) with single cable-typed wire was established based on the theory of arc physics. The influences of different shielding gas flow rates on the features of temperature field, velocity field and pressure field were investigated. The results showed that the maximum velocity of arc plasma along radial direction and the arc pressure on the surface of workpieces were increased obviously with the increase of the shielding gas flow rate, while the arc temperature was changed little. This phenomenon was mainly attributed to the increasing collisions between arc plasmas and the self-rotation action of cable-typed wires. The arc temperature at the tip of the cable-typed wire reached the maximum. The maximum flow velocity of arc plasma was located at the tip of wire (2–8 mm). The arc pressures in the central axis reached the maximum pressure. The simulation results were in agreement with the experimental results.

Simulation and Experimental Study of a Porous Electroosmotic Pump

2011 ◽  
Vol 483 ◽  
pp. 320-326 ◽  
Author(s):  
Zhou Ling ◽  
Tao Yang ◽  
Fan Chao Meng ◽  
Lin Yi ◽  
Xiang Xian Zhang
Keyword(s):  
Porous Media ◽  
Flow Rate ◽  
Pore Diameter ◽  
Maximum Flow ◽  
Joule Heat ◽  
Maximum Pressure ◽  
Electrical Field ◽  
Electroosmotic Pump ◽  
The Mathematical Model ◽  
Truncated Gaussian

Aiming at the coupling problems of electrical field and flow field in porous media microchannels, the mathematical model of electroosmotic(EO) flow is built. For a single microchannel, the influence of voltage on velocity and joule heat is analyzed by using CoventorWare. Numerical analysis shows that the velocity is proportional to the voltage and the joule heat is small and negligible. For the porous media, the flow rate is investigated by truncated Gaussian distribution of pore diameter. The electroosmotic microporous pump is fabricated, and the experimental results indicate that the maximum flow rate of porous media micropump is 16.89ml/min and the maximum pressure is 120.1kPa.

scholarly journals Simulation of a Chain of Collapsible Contracting Lymphangions With Progressive Valve Closure

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
C. D. Bertram ◽  
C. Macaskill ◽  
J. E. Moore
Keyword(s):  
Flow Rate ◽  
Flow Direction ◽  
Maximum Flow ◽  
Transmural Pressure ◽  
Maximum Flow Rate ◽  
Smooth Transition ◽  
Maximum Pressure ◽  
Mean Flow ◽  
Forward Flow ◽  
In Series

The aim of this investigation was to achieve the first step toward a comprehensive model of the lymphatic system. A numerical model has been constructed of a lymphatic vessel, consisting of a short series chain of contractile segments (lymphangions) and of intersegmental valves. The changing diameter of a segment governs the difference between the flows through inlet and outlet valves and is itself governed by a balance between transmural pressure and passive and active wall properties. The compliance of segments is maximal at intermediate diameters and decreases when the segments are subject to greatly positive or negative transmural pressure. Fluid flow is the result of time-varying active contraction causing diameter to reduce and is limited by segmental viscous and valvular resistance. The valves effect a smooth transition from low forward-flow resistance to high backflow resistance. Contraction occurs sequentially in successive lymphangions in the forward-flow direction. The behavior of chains of one to five lymphangions was investigated by means of pump function curves, with variation of valve opening parameters, maximum contractility, lymphangion size gradation, number of lymphangions, and phase delay between adjacent lymphangion contractions. The model was reasonably robust numerically, with mean flow-rate generally reducing as adverse pressure was increased. Sequential contraction was found to be much more efficient than synchronized contraction. At the highest adverse pressures, pumping failed by one of two mechanisms, depending on parameter settings: either mean leakback flow exceeded forward pumping or contraction failed to open the lymphangion outlet valve. Maximum pressure and maximum flow-rate were both sensitive to the contractile state; maximum pressure was also determined by the number of lymphangions in series. Maximum flow-rate was highly sensitive to the transmural pressure experienced by the most upstream lymphangions, suggesting that many feeding lymphatics would be needed to supply one downstream lymphangion chain pumping at optimal transmural pressure.

Preparation and Evaluation of Monolithic Silica Capillary Column for Reversed-Phase Capillary Liquid Chromatography

2012 ◽  
Vol 485 ◽  
pp. 136-139
Author(s):  
Ya Shun Chen ◽  
Li Jia ◽  
Wei Liu ◽  
Zhong Zhou Yi ◽  
Fang Fang He
Keyword(s):  
Liquid Chromatography ◽  
Sol Gel ◽  
Capillary Columns ◽  
Reversed Phase ◽  
Capillary Liquid Chromatography ◽  
Fused Silica ◽  
Monolithic Silica ◽  
Fused Silica Capillary ◽  
Capillary Liquid ◽  
Silica Capillary

Octadecyl-functionalized monolithic silica capillary columns with inner diameters of 100 and 200 micrometers for reversed-phase capillary liquid chromatography were prepared in the fused-silica capillary via sol-gel process. Their performance was evaluated and compared by the separation of alkylbenzenes (toluene, ethylbenzene, propylbenzene, butylbenzene). The column back pressure and linear velocity of mobile phase were investigated. The results show that the monolithic silica capillary columns exhibit good performance for the separation of alkylbenzenes.

Piezo-Actuated Valveless Micropumps for Micro-Total Analysis Systems

2010 ◽  
Author(s):  
Arvind Chandrasekaran ◽  
Muthukumaran Packirisamy
Keyword(s):  
Flow Rate ◽  
Glass Substrate ◽  
Flow Characteristics ◽  
Low Frequency ◽  
Lab On A Chip ◽  
Maximum Flow ◽  
Valveless Micropump ◽  
Chip Flow ◽  
Micro Total Analysis Systems ◽  
Total Analysis

In this work, a Piezo actuated Valveless micropump is proposed for applications in Micro-Total Analysis Systems (μTAS) and Lab-on-a-Chip. Flow rectification in the micropump has been brought about with the use of a diffuser element. The device is fabricated on PDMS-Glass substrate with the glass acting as the diaphragm. A PZT disc is integrated with the setup for actuation. The micropump has been characterized for its dynamic behavior, flow characteristics, and pressure. It was found that the maximum flow rate for the micropump was obtained at low frequency which makes it usable for practical μTAS applications.

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