Comparing Piezoelectric and Electroosmotic Micropumps for Biomedical Devices

2008 ◽  
Author(s):  
Omer San ◽  
Sinan Eren Yalcin ◽  
Oktay Baysal
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Biomedical Applications ◽  
Low Voltage ◽  
Check Valve ◽  
Back Pressure ◽  
Driving Voltage ◽  
Major Drawback ◽  
Dominant Type ◽  
Flow Rates

A micropump is an essential component of a microfluidic lab-on-a-chip device, especially for their biomedical applications. Based on their actuation method to drive the fluid flow, pumps may be categorized as mechanical or non-mechanical devices. In our proposed paper, we will report our comparative study of the most promising micropumps in each of these categories: a piezoelectrically-actuated micropump (PAμP) and an electroosmotic micropump (EOμP). A PAμP requires relatively high applied voltage, but provides high flow rates and has emerged to be the dominant type of micropump in biomedical applications. A valveless diffuser-nozzle micropump, driven by an oscillating membrane, has an important advantage, since the fabrication of any additional moving part, such as a check valve, would add significantly to its cost and render a more failure-prone device. The piezoelectrically actuated, valveless micropumps use moving mechanical parts to pump fluid and control the flow with optimized actuation frequency and applied voltage. In the present study, the microflow-structure interaction in the PAμP is modeled using an arbitrary Lagrangian-Eulerian method including a parametric study of applied voltage and frequency. An EOμP consists of multiple micron-scale channels in parallel that are subjected to the electroosmotic effect. However, a major drawback in the conventional design of an EOμP is the need for a high driving voltage to increase the flow rate or to overcome the back pressure. In the present study, a low-voltage EOμP is proposed and computationally modeled. Our simulations are performed in order to study the low-voltage EOμP for its various flow rate and back pressure characteristics. In the proposed paper, we will discuss our comparisons of PAμP and EOμP, with respect to their actuation mechanisms, applied voltages, pump sizes, flow rates and back pressures.

Basic Study for Micro Pump Using Electroosmotic Flow

2003 ◽  
Author(s):  
Tamio Fujiwara ◽  
Akinori Kamiya ◽  
Osami Kitoh ◽  
Tatsuo Ushijima
Keyword(s):  
Pressure Gradient ◽  
Flow Rate ◽  
Applied Voltage ◽  
Electroosmotic Flow ◽  
Great Influence ◽  
Smoluchowski Equation ◽  
Flow Meter ◽  
Flow Rates ◽  
Micro Pump ◽  
Gap Width

The characteristic features of electroosmotic flow have been studied to obtain important information for applying the flow to a micro pump as a driving device. Here, an electroosmotic flow of water was generated in a donut channel constructed by a gap between two parallel donut-shaped glass plates. The flow rate was measured in relation to the applied voltage, the gap width of the channel, the pressure gradient and the properties of the fluid. The experimental results were compared with a theoretical equation of electroosmosis, the Helmholtz-Smoluchowski equation, which predicts that the electroosmotic flow rate is proportional to the applied voltage as well as to the gap width. The Electroosmotic flow rate increased linearly with the applied voltage. however, there appeared some particular voltage ranges of nonlinear relation unlike the Helmholtz-Smoluchowski equation. The water properties (the conductivity and the kinds of impurities included) had a great influence on the electroosmotic flow rate characteristics including the degree of non-linearity and even the flow direction. The cause of these phenomena has not been clarified. It is conjectured that the zeta potential of the glass-water interface was altered by the applied electric field. It is confirmed that the electroosmotic flow rate is proportional to the gap size of the channel. When a pressure gradient existed in the direction of the electroosmotic flow, the total flow rate was given as a sum of the flow rates of the electroosmotic and Poiseuille flows. These findings provide important information for micro pumps. For measuring the electroosmotic flow rate, we developed a micro flow meter consisting of a capillary and two fine wires. This flow meter makes it possible to measure a flow rate the order of 1×10−3 mm3/sec (= 1 nl/sec) and has a potential ability to measure even much smaller flow rates.

Fabrication and Performance Characterization of a Disposable Micropump Actuated by Piezoelectric-Disc

2011 ◽  
Vol 254 ◽  
pp. 179-182 ◽  
Author(s):  
Ling Ling Sun ◽  
Shan Zhong Wang ◽  
Ling Na Li ◽  
Jin Lan Guo ◽  
Siti Fatimatuzzahra Binti Roseli
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Glass Substrate ◽  
Performance Testing ◽  
Microfluidic System ◽  
Driving Voltage ◽  
Pump Rate ◽  
And Performance ◽  
Piezoelectric Disc

Micropumps represent one of the major components in microfluidic technology. This paper describes the fabrication and performance testing of a simple, compact, inexpensive and disposable micropump suitable for microfluidic applications. The micropump was fabricated with polydimethylsiloxane (PDMS) which was bonded permanently on glass substrate. Piezoelectric-discs were used to actuate the micropumps. As a flow-rectifying element, the diffusers were used instead of passive check valves. The performances of the micropump, such as pump rate, were characterized. The flow rate of micropump increases with enhancing the applied voltage to piezoelectric-disc due to the increase of diaphragm deflection. The flow rate of the micropump with diffusers were about 9 μl/min when applying a 20 V square wave driving voltage at 300 Hz. This prototype can be used as a platform to develop an inexpensive micropump which is suitable to be part of a disposable microfluidic system.

Symmetrical Ball Check-Valve Based Rotation-Sensitive Pump

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Fábio A. Rahal ◽  
Cyro Ketzer Saul
Keyword(s):  
Check Valve ◽  
Laser Machining ◽  
Driving Voltage ◽  
Proof Of Concept ◽  
Flow Rates ◽  
Membrane Pump ◽  
Valve System ◽  
Wide Range ◽  
Electromagnetically Actuated ◽  
Simple Rotation

In this work an electromagnetically actuated membrane pump, which allows flow reversion with a simple rotation of its valve system, is presented as a proof of concept. The valve system combines two symmetrical ball check-valves (SBCV), fabricated using laser machining techniques on PMMA (poly-methyl methacrylate) and PDMS (polydimethylsiloxane). The best efficiencies were achieved using glass balls within the SBCVs. This configuration provides flow rates from 0.2 to 6.0 ml/min with pressures up to 7 kPa. We also present a model which allows simulating the pumping behavior qualitatively, including the reversion after the rotation. The main advantages of the presented pump are wide range flow rates, low driving voltage (below 30 V), same pressure and flow rate in both direct and reverse pumping modes, and easily scalable to both bigger and smaller dimensions.

Low Voltage Bifurcations in a Diode Resonator

1997 ◽  
Vol 07 (04) ◽  
pp. 849-854
Author(s):  
Youngtae Kim ◽  
Jong Cheol Shin ◽  
Sook-Il Kwun
Keyword(s):  
Numerical Simulations ◽  
Equivalent Circuit ◽  
Applied Voltage ◽  
Low Voltage ◽  
Period Doubling ◽  
Period Doubling Bifurcation ◽  
Driving Voltage ◽  
One Dimensional ◽  
Sudden Jump ◽  
Good Agreement

We have observed an interesting bifurcation sequence at very low driving voltages applied to a diode resonator. As the driving voltage increases, an ordinary period-doubling bifurcation appears. Further increase of the driving voltage results in a reverse period-doubling bifurcation and a sudden jump of an amplitude of the current oscillation of the diode. The experimental results were compared with the results of numerical simulations of the equivalent circuit of the diode resonator and they were in good agreement. This suggests that these low-voltage bifurcations are due to nonlinearity of the capacitance and current of the diode to the applied voltage. A simple one-dimensional map explaining these low-voltage bifurcations of the diode resonator is introduced and its properties are discussed.

Changes in canine saliva ion concentration induced by increased intraluminal pressure

1976 ◽  
Vol 231 (3) ◽  
pp. 974-978 ◽  
Author(s):  
KA Siegel
Keyword(s):  
Flow Rate ◽  
Ionic Composition ◽  
Sodium Concentration ◽  
Salivary Flow ◽  
Back Pressure ◽  
Ion Concentration ◽  
Intraluminal Pressure ◽  
Total Output ◽  
Flow Rates ◽  
Saliva Flow

Hydrostatic pressure was applied to a cannula inserted into Wharton's duct of adult dogs anesthetized with pentobarbital and the effect of pressure on saliva flow rate and ionic composition of saliva was measured. Increasing the back pressure on a secreting gland resulted in a decrease in flow rate. Over the range of 0-100 mmHg back pressure the decrease in flow was proportional to the applied back pressure. The potassium concentration of saliva collected in the absence of back pressure and at raised pressure was similar even though back pressure reduced flow. In contrast, sodium concentration decreased when back pressure caused salivary flow rate to be reduced. However, when examined at the same flow rates the concentration of sodium is increased when back pressure is applied to the gland as compared to absence of back pressure. Under conditions of constant stimulation the total output of sodium and potassium into saliva decreases as back pressure is increased; but when equal flow rates are compared total sodium output increases in the presence of applied back pressure, whereas potassium output remains constant.

scholarly journals Development of a High Flow Rate 3-D Electroosmotic Flow Pump

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 112 ◽  
Author(s):  
Zi Ye ◽  
Renchang Zhang ◽  
Meng Gao ◽  
Zhongshan Deng ◽  
Lin Gui
Keyword(s):  
Flow Rate ◽  
Electroosmotic Flow ◽  
Room Temperature ◽  
Low Voltage ◽  
Fluid Layer ◽  
High Flow ◽  
Driving Voltage ◽  
Temperature Liquid ◽  
Contact Electrodes ◽  
Flow Pump

A low voltage 3D parallel electroosmotic flow (EOF) pump composed of two electrode layers and a fluid layer is proposed in this work. The fluid layer contains twenty parallel fluid channels and is set at the middle of the two electrode layers. The distance between fluid and electrode channels was controlled to be under 45 μm, to reduce the driving voltage. Room temperature liquid metal was directly injected into the electrode channels by syringe to form non-contact electrodes. Deionized (DI) water with fluorescent particles was used to test the pumping performance of this EOF pump. According to the experimental results, a flow rate of 5.69 nL/min was reached at a driving voltage of 2 V. The size of this pump is small, and it shows a great potential for implanted applications. This structure could be easily expanded for more parallel fluid channels and larger flow rate.

Improved method for the use of proportioning injectors to condition large volumes of water for virological analysis

1981 ◽  
Vol 27 (4) ◽  
pp. 455-457 ◽  
Author(s):  
Pierre Payment ◽  
Michel Trudel
Keyword(s):  
Flow Rate ◽  
Back Pressure ◽  
Low Flow ◽  
Improved Method ◽  
Flow Rates ◽  
Pressure Buildup ◽  
Sampling Procedures ◽  
Virological Monitoring ◽  
Low Flow Rate

A bypass system with a valve permits the use of low flow rate injecting proportioners, which are much less sensitive to back pressure buildup. The system can be used to condition water at flow rates of 1–15 L/min during sampling procedures for virological monitoring by the Wallis–Melnick method.

Effect of Processing Parameters on the Diameter and Morphology of Electrospun Iron-Modified Montmorillonite (Fe-MMT)/Polycaprolactone Nanofibers

2020 ◽  
Vol 846 ◽  
pp. 14-22
Author(s):  
Gianina Martha A. Tajanlangit ◽  
Leslie Joy L. Diaz
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Low Voltage ◽  
Fiber Diameter ◽  
Significant Loss ◽  
Fractional Factorial ◽  
Average Fiber Diameter ◽  
Fiber Morphology ◽  
Modified Montmorillonite ◽  
Needle Diameter

Iron-modified montmorillonite-filled polycaprolactone nanofiber mats were produced via electrospinning with varying applied voltage, flow rate, needle-tip-to-collector distance, and needle diameter. Scanning electron microscopy (SEM) was used to observe fiber morphology and characteristics. The effects of varying process parameters on various fiber characteristics were evaluated using a two-level fractional factorial experimental design. The effect of voltage on fiber diameter differed with varying flow rate. At 32 ml/hr, the average fiber diameter decreased from 518.38 nm ± 289.37 nm to 466.43 nm ± 312.36 nm when the voltage is increased. At 42 ml/hr the effect of voltage on fiber diameter was reversed. The average fiber diameter was also found to decrease from 516.03 nm ± 283.48 nm to 467.96 nm ± 318.07 nm with decreasing tip-to-collector distance at 32 mL/hr flow rate. The variation of the effect of the factors on fiber diameter was mainly due to a significant loss of material observed at 12 kV and 15 cm tip-to-collector distance. Bead formation was observed for all runs with more beads being formed at 12 kV applied voltage and 15 cm tip-to-collector distance. Spherical beads were observed at 12 kV and 15 cm tip-to-collector distance while spindle-like beads were present in nanofiber membranes spun at high voltage and at the combination of low voltage and low tip-to-collector distance. The parameter setting combination of 19 kV, 32 ml/hr flow rate, 10 cm tip-to-collector distance, and 0.514 mm needle diameter yielded the lowest fiber diameter with the least amount of beading and small bead size. Small fiber diameters and less beading provide larger surface area and more exposure of the Fe-MMT particles for more efficient adsorption.

Hydraulic model of a water cooling system in a chemical plant

1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Cooling Water ◽  
Graph Algorithm ◽  
Automatic Generation ◽  
Hydraulic Calculation ◽  
Return Flow ◽  
Flow Rates ◽  
Pressure Losses ◽  
Controlled Flow

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.

scholarly journals Research on a Piezoelectric Pump with Flexible Valves

2021 ◽  
Vol 11 (7) ◽  
pp. 2909
Author(s):  
Weiqing Huang ◽  
Liyi Lai ◽  
Zhenlin Chen ◽  
Xiaosheng Chen ◽  
Zhi Huang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Fluid Transport ◽  
Smooth Transition ◽  
Driving Voltage ◽  
Piezoelectric Pump ◽  
Venous Valve ◽  
Output Pressure ◽  
Small Flow ◽  
Working Principle ◽  
Opening And Closing

Imitating the structure of the venous valve and its characteristics of passive opening and closing with changes in heart pressure, a piezoelectric pump with flexible valves (PPFV) was designed. Firstly, the structure and the working principle of the PPFV were introduced. Then, the flexible valve, the main functional component of the pump, was analyzed theoretically. Finally, an experimental prototype was manufactured and its performance was tested. The research proves that the PPFV can achieve a smooth transition between valved and valveless by only changing the driving signal of the piezoelectric (PZT) vibrator. The results demonstrate that when the driving voltage is 100 V and the frequency is 25 Hz, the experimental flow rate of the PPFV is about 119.61 mL/min, and the output pressure is about 6.16 kPa. This kind of pump can realize the reciprocal conversion of a large flow rate, high output pressure, and a small flow rate, low output pressure under the electronic control signal. Therefore, it can be utilized for fluid transport and pressure transmission at both the macro-level and the micro-level, which belongs to the macro–micro combined component.

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