Development of a high performance peristaltic micropump
Pham, My; Goo, Nam Seo
2008-03-01
In this study, a high performance peristaltic micropump has been developed and investigated. The micropump has three cylinder chambers which are connected through micro-channels for high pumping pressure performance. A circular-shaped mini LIPCA has been designed and manufactured for actuating diaphragm. In this LIPCA, a 0.1mm thickness PZT ceramic is used as an active layer. As a result, the actuator has shown to produce large out of plane deflection and consumed low power. During the design process, a coupled field analysis was conducted to predict the actuating behavior of a diaphragm and pumping performance. MEMS technique was used to fabricate the peristaltic micropump. Pumping performance of the present micropump was investigated both numerically and experimentally. The present peristaltic micropump was shown to have higher performance than the same kind of micropump developed else where.
Development and characterization of thermopneumatic peristaltic micropumps
In this paper, the development and characterization of thermopneumatic peristaltic micropumps are presented. Micropumps with three different designs are fabricated using soft lithography techniques. The equivalent circuit models of a thermopneumatic actuation cell are formulated. The analytical solutions for predicting the device transient behavior are also derived. The dynamical responses of the diaphragms are measured using an interferometer, and are in good agreement with the modeled results. Tiny drive circuits, which require only 5 V, are implemented for driving the pumps. The dimension of an integrated 3-chamber micropump system, which consists of a pump and a drive circuit, is 16 mm × 18 mm × 5.5 mm. The optimal operating conditions, such as actuation sequences, operating frequencies and duty ratios, are obtained. The maximum flow rate occurs at a driving frequency of 1.5 Hz with a duty ratio of 40% using a three-phase actuation sequence. A simplified pseudo thermo-fluid-structure-interaction (pT-FSI) model is also proposed to estimate the pumping characteristic. The model gives reasonable results under low operation frequency. Under zero backpressure, the maximum flow rates for the 3, 5 and 7-chamber devices are very close, whereas the devices with larger numbers of pumping chambers exhibit better pumping performance under higher backpressure
Development and characterization of thermopneumatic peristaltic micropumps
Yang, Yao-Joe; Liao, Hsin-Hung
2009-02-01
In this paper, the development and characterization of thermopneumatic peristaltic micropumps are presented. Micropumps with three different designs are fabricated using soft lithography techniques. The equivalent circuit models of a thermopneumatic actuation cell are formulated. The analytical solutions for predicting the device transient behavior are also derived. The dynamical responses of the diaphragms are measured using an interferometer, and are in good agreement with the modeled results. Tiny drive circuits, which require only 5 V, are implemented for driving the pumps. The dimension of an integrated 3-chamber micropump system, which consists of a pump and a drive circuit, is 16 mm × 18 mm × 5.5 mm. The optimal operating conditions, such as actuation sequences, operating frequencies and duty ratios, are obtained. The maximum flow rate occurs at a driving frequency of 1.5 Hz with a duty ratio of 40% using a three-phase actuation sequence. A simplified pseudo thermo-fluid-structure-interaction (pT-FSI) model is also proposed to estimate the pumping characteristic. The model gives reasonable results under low operation frequency. Under zero backpressure, the maximum flow rates for the 3, 5 and 7-chamber devices are very close, whereas the devices with larger numbers of pumping chambers exhibit better pumping performance under higher backpressure.
A vacuum-driven peristaltic micropump with valved actuation chambers
This paper presents a simple peristaltic micropump design incorporated with valved actuation chambers and propelled by a pulsed vacuum source. The vacuum-driven peristaltic micropump offers high pumping rates, low backflow, appreciable tolerance to air bubbles, and minimal destruction to fluid contents. The pumping device, fabricated by laser micromachining and plasma bonding of three polydimethylsiloxane (PDMS) layers, includes a pneumatic network, actuation membranes, and microfluidic channels. As the key to peristaltic motion, the sequential deflection of the elastic membranes is achieved by periodic pressure waveforms (negative) traveling through the pneumatic network, provided by a vacuum source regulated by an electromagnetic valve. This configuration eliminates the complicated control logic typically required in peristaltic motion. Importantly, the valved actuation chambers substantially reduce backflow and improve the pumping rates. In addition, the pneumatic network with negative pressure provides a means to effectively remove air bubbles present in the microflow through the gas-permeable PDMS membrane, which can be highly desired in handling complex fluidic samples. Experimental characterization of the micropump performance has been conducted by controlling the resistance of the pneumatic network, the number of normally closed valves, the vacuum pressure, and the frequency of pressure pulses. A maximal flow rate of 600 µL min−1 has been optimized at the pulsed vacuum frequency of 30 Hz with a vacuum pressure of 50 kPa, which is comparable to that of compressed air-actuated peristaltic micropumps
A peristaltic micropump using traveling waves on a polymer membrane
We demonstrate a peristaltic micropump that utilizes traveling waves on polymer membranes to transport liquids. This micropump requires no valves and, more importantly, the traveling waves can be generated by a single actuator. These features enable the design of simple, compact devices. This micropump has a hydraulic displacement amplification mechanism (HDAM) that encapsulates an incompressible fluid with flexible polymer membranes made of polydimethyl siloxane. A microchannel is attached to the top side of the HDAM. We used a cantilever-type piezoelectric actuator to oscillate the flexible membrane at the bottom of the HDAM, while the top-side membrane drives the liquid in the channel. This format enables rectangular parallelepiped micropumps as compact as 36 mm long, 10 mm wide and several millimeters high, depending on the channel height. Experiments using the fabricated micropumps equipped with microchannels of various heights revealed that the flow rate was dependent on the ratio of the amplitude of the traveling waves to the height of the fluidic channel. The manufactured micropump could successfully generate a maximum flow rate of 1.5 ml min−1 at 180 mW. (paper)
PDMS Based Thermopnuematic Peristaltic Micropump for Microfluidic Systems
A thermopnuematic peristaltic micropump for controlling micro litters of fluid was designed and fabricated from multi-stack PDMS structure on glass substrate. Pump structure consists of inlet and outlet, microchannel, three thermopneumatic actuation chambers, and three heaters. In microchannel, fluid is controlled and pumped by peristaltic motion of actuation diaphragm. Actuation diaphragm can bend up and down by exploiting air expansion that is induced by increasing heater temperature. The micropump characteristics were measured as a function of applied voltage and frequency. The flow rate was determined by periodically recording the motion of fluid at Nanoport output and computing flow volume from height difference between consecutive records. From the experiment, an optimum flow rate of 0.82 μl/min is obtained under 14 V three-phase input voltages at 0.033 Hz operating frequency
Portable Valve-less Peristaltic Micro-pump Design and Fabrication
Yang, H; Hu, C -C
2008-01-01
This paper is to describe a design and fabrication method for a valve-less peristaltic micro-pump. The valve-less peristaltic micro-pump with three membrane chambers in a serial is actuated by three piezoelectric (PZT) actuators. With the fluidic flow design, liquid in the flow channel is pumped to a constant flow speed ranged from 0.4 to 0.48 mm/s. In term of the maximum flow rate of the micro-pump is about 365 mircoliters/min, when the applied voltage is 24V and frequency 50 Hz. Photolithography process was used to fabricate the micro-pump mold. PDMS molding and PDMS bonding method were used to fabricate the micro-channel and actuator chambers. A portable drive controller was designed to control three PZT actuators in a proper sequence to drive the chamber membrane. Then, all parts were integrated into the portable valve-less peristaltic micro-pump system.
Portable Valve-less Peristaltic Micro-pump Design and Fabrication
Yang, H.; Tsai, T.-H.; Hu, C.-C.
2008-01-01
This paper is to describe a design and fabrication method for a valve-less peristaltic micro-pump. The valve-less peristaltic micro-pump with three membrane chambers in a serial is actuated by three piezoelectric (PZT) actuators. With the fluidic flow design, liquid in the flow channel is pumped to a constant flow speed ranged from 0.4 to 0.48 mm/s. In term of the maximum flow rate of the micro-pump is about 365 mircoliters/min, when the applied voltage is 24V and frequency 50 Hz. Photolithog...
Huang, Pao-Cheng; Wang, Min-Haw; Chen, Ming-Kun; Jang, Ling-Sheng
2016-05-01
Flow rate sensing is a critical issue for piezoelectric-based micropump systems. This paper describes experimental analysis of flow rate sensing in a peristaltic micropump system. Sensing can be integrated with such a pump using piezoelectric actuators based on the time-phase-shift (TPS) method. To do this, an evaluation-window is added on the falling edge of the driving pulse to help detect the flow velocity without affecting the flow rate. We fabricate a prototype piezoelectric peristaltic micropump with three chambers and three piezoelectric actuators. The middle actuator works not only as an actuator for driving fluid but also as a transducer for sensing flow rate. An evaluation-window is performed to ascertain the relationship between the flow rate and the phase shift of output-signal responses from the transducer. The experimental results show that the evaluation-window response of flow rates in a piezoelectric peristaltic micropump has rates of from 5.56‒33.36 μl s-1. The results are extended to propose a practical flow rate sensor, the design of which can be realized easily in the piezoelectric peristaltic micropump system for sensorless responses that can detect flow rate without any sensors or circuits. The proposed TPS method is real-time, integrated, fast, efficient, and suitable for flow rate detection in piezoelectric peristaltic micropumps.
Development of a peristaltic gas micropump with a single chamber and multiple electrodes
This paper reports on the development of a multi-electrode electrostatically driven peristaltic gas micropump. The micropump consists of a single chamber and a flexible diaphragm with a multi-electrode pattern. The single-chamber design is divided into smaller cells by the electrodes; the characteristic operating frequency of the micropump increases as the number of electrodes increases. The flow rate is also observed to increase to maximum before decreasing for larger numbers of electrodes. Whereas the maximum flow rate of a 4-electrode micropump is about 40 µl min−1 at 14 Hz, the maximum flow rate of the 16-electrode micropump is about 250 µl min−1 at 1400 Hz and that of the 32-electrode micropump is 150 µl min−1 at 4000 Hz. (paper)
Development of a peristaltic micropump for bio-medical applications based on mini LIPCA
Pham, My; Nguyen, Thanh Tung; Goo, Nam Seo
2008-01-01
This paper presents the design, fabrication, and experimental characterization of a peristaltic micropump. The micropump is composed of two layers fabricated from polydimethylsiloxane (PDMS) material. The first layer has a rectangular channel and two valve seals. Three rectangular mini lightweight piezo-composite actuators are integrated in the second layer, and used as actuation parts. Two layers are bonded, and covered by two polymethyl methacrylate (PMMA) plates, which help increase the st...
Dynamic simulation of a peristaltic micropump considering coupled fluid flow and structural motion
Lin, Qiao; Yang, Bozhi; Xie, Jun; Tai, Yu-Chong
2007-01-01
This paper presents lumped-parameter simulation of dynamic characteristics of peristaltic micropumps. The pump consists of three pumping cells connected in series, each of which is equipped with a compliant diaphragm that is electrostatically actuated in a peristaltic sequence to mobilize the fluid. Diaphragm motion in each pumping cell is first represented by an effective spring subjected to hydrodynamic and electrostatic forces. These cell representations are then used to construct a system...
Development of a peristaltic micropump for bio-medical applications based on mini LIPCA
Pham, My; Goo, Nam Seo
2008-01-01
This paper presents the design, fabrication, and experimental characterization of a peristaltic micropump. The micropump is composed of two layers fabricated from polydimethylsiloxane (PDMS) material. The first layer has a rectangular channel and two valve seals. Three rectangular mini lightweight piezo-composite actuators are integrated in the second layer, and used as actuation parts. Two layers are bonded, and covered by two polymethyl methacrylate (PMMA) plates, which help increase the stiffness of the micropump. A maximum flow rate of 900 mokroliter per min and a maximum backpressure of 1.8 kPa are recorded when water is used as pump liquid. We measured the power consumption of the micropump. The micropump is found to be a promising candidate for bio-medical application due to its bio-compatibility, portability, bidirectionality, and simple effective design.
Development of a Peristaltic Micropump for Bio-Medical Applications Based on Mini LIPCA
Thanh Tung Nguyen; My Pham; Nam Seo Goo
2008-01-01
This paper presents the design, fabrication, and experimental characterization of a peristaltic micropump. The micropump is composed of two layers fabricated from Polydimethylsiloxane (PDMS) material. The first layer has a rectangular channel and two valve seals. Three rectangular mini lightweight piezo-composite actuators are integrated in the second layer, and used as actuation parts.Two layers are bonded, and covered by two Polymethyl Methacrylate (PMMA) plates, which help increase the stiffness of the micropump.A maximum flow rate of 900 uL·min-1 and a maximum backpressure of 1.8 kPa are recorded when water is used as pump liquid. We measured the power consumption of the micropump. The micropump is found to be a prom- ising candidate for bio-medical application due to its bio-compatibility, portability, bidirectionality, and simple effective design.
Design and dynamic characterization of "single-stroke" peristaltic PDMS micropumps.
Lai, Hoyin; Folch, Albert
2011-01-21
In this paper, we present a monolithic PDMS micropump that generates peristaltic flow using a single control channel that actuates a group of different-sized microvalves. An elastomeric microvalve design with a raised seat, which improves bonding reliability, is incorporated into the micropump. Pump performance is evaluated based on several design parameters--size, number, and connection of successive microvalves along with control channel pressure at various operating frequencies. Flow rates ranging 0-5.87 µL min(-1) were observed. The micropump design demonstrated here represents a substantial reduction in the number of/real estate taken up by the control lines that are required to run a peristaltic pump, hence it should become a widespread tool for parallel fluid processing in high-throughput microfluidics. PMID:20957288
Effect of actuation sequence on flow rates of peristaltic micropumps with PZT actuators.
Jang, Ling-Sheng; Shu, Kuan; Yu, Yung-Chiang; Li, Yuan-Jie; Chen, Chiun-Hsun
2009-02-01
Many biomedical applications require the administration of drugs at a precise and preferably programmable rate. The flow rate generated by the peristaltic micropumps used in such applications depends on the actuation sequence. Accordingly, the current study performs an analytical and experimental investigation to determine the correlation between the dynamic response of the diaphragms in the micropump and the actuation sequence. A simple analytical model of a peristaltic micropump is established to analyze the shift in the resonant frequency of the diaphragms caused by the viscous damping effect. The analytical results show that this damping effect increases as the oscillation frequency of the diaphragm increases. A peristaltic micropump with three piezoelectric actuators is fabricated on a silicon substrate and is actuated using 2-, 3-, 4- and 6-phase actuation sequences via a driving system comprising a microprocessor and a phase controller. A series of experiments is conducted using de-ionized water as the working fluid to determine the diaphragm displacement and the flow rates induced by each of the different actuation sequences under phase frequencies ranging from 50 Hz to 1 MHz. The results show that the damping effect of actuation sequences influences diaphragm resonant frequency, which in turn affects the profiles of flow rates. PMID:18821016
Dynamic simulation of a peristaltic micropump considering coupled fluid flow and structural motion
Lin, Qiao; Yang, Bozhi; Xie, Jun; Tai, Yu-Chong
2007-02-01
This paper presents lumped-parameter simulation of dynamic characteristics of peristaltic micropumps. The pump consists of three pumping cells connected in series, each of which is equipped with a compliant diaphragm that is electrostatically actuated in a peristaltic sequence to mobilize the fluid. Diaphragm motion in each pumping cell is first represented by an effective spring subjected to hydrodynamic and electrostatic forces. These cell representations are then used to construct a system-level model for the entire pump, which accounts for both cell- and pump-level interactions of fluid flow and diaphragm vibration. As the model is based on first principles, it can be evaluated directly from the device's geometry, material properties and operating parameters without using any experimentally identified parameters. Applied to an existing pump, the model correctly predicts trends observed in experiments. The model is then used to perform a systematic analysis of the impact of geometry, materials and pump loading on device performance, demonstrating its utility as an efficient tool for peristaltic micropump design.
Rotary Peristaltic Micro-Pump Based on the Nano-Magnetic Fluid%基于纳米磁性液体的旋转式蠕动微泵
吴健; 刘同冈; 张亮
2013-01-01
A rotary peristaltic micro-pump based on the nano-magnetic fluid was designed,which was composed of an upper substrate,a lower substrate and an elastic film positioned between the two substrates.A micro-channel was machined on each substrate,the magnetic fluid in the upper micro-channel was gathered by a permanent magnet to deform the elastic film in order to push the sample liquid in the lower micro-channel.Both micro-channels were designed with the ring structure to pump the liquid continuously.The operational result indicates that the flow rate and output pressure are the combination result of the positive pressure generated by the gradient magnetic field and the driving force produced by the moving magnetic field.When the rotational speed of the magnetic field is 6 r/min,the maximum output pressure and flow rate of the micro-pump are 1 600 Pa and 1.8 mL/min,respectively.%设计了一种基于纳米磁性液体的旋转式蠕动微泵.泵体由上、下基板和弹性薄膜组成,弹性薄膜位于上、下基板的中间位置.在上、下基板上分别加工出微型管道,上管道中的纳米磁性液体在磁场作用下压迫弹性薄膜变形,从而推动下管道中的液体流动,并且采用环形结构,实现连续泵送的目的.运行结果显示:泵送流量和泵送压力是梯度磁场产生的正压力与移动磁场产生的驱动力共同作用的结果.当磁场旋转速度达到6 r/min时,微泵产生的最大泵送压力达1 600 Pa,此时的流量为1.8 mL/min.
Chi-Han Chiou; Tai-Yen Yeh; Jr-Lung Lin
2015-01-01
This study presents a double-side diaphragm peristaltic pump for efficient medium transport without the unwanted backflow and the lagging effect of a diaphragm. A theoretical model was derived to predict the important parameter of the micropump, i.e., the motion of the valves at large deformations, for a variety of air pressures. Accordingly, we proposed an easy and robust design to fabricate a Polydimethylsiloxane (PDMS)-based micropump. The theoretical model agrees with a numerical model an...
Chi-Han Chiou
2015-01-01
Full Text Available This study presents a double-side diaphragm peristaltic pump for efficient medium transport without the unwanted backflow and the lagging effect of a diaphragm. A theoretical model was derived to predict the important parameter of the micropump, i.e., the motion of the valves at large deformations, for a variety of air pressures. Accordingly, we proposed an easy and robust design to fabricate a Polydimethylsiloxane (PDMS-based micropump. The theoretical model agrees with a numerical model and experimental data for the deformations of the PDMS membrane. Furthermore, variations of the generated flow rate, including pneumatic frequencies, actuated air pressures, and operation modes were evaluated experimentally for the proposed micropumps. In future, the theoretical equation could provide the optimal parameters for the scientists working on the fabrication of the diaphragm peristaltic pump for applications of cell-culture.
Hansen, Thomas Steen; Larsen, Niels Bent; Hassager, Ole
2008-01-01
In this thesis an all polymer micropump, and the fabrication method required to fabricate this, are examined. Polymer microfluidic. devices are of major scientific interest because they can combine complicated chemical and biological analys~s in cheap and disposable devices. The electrode system in the micropump is based on the conducting polymer poly(3,4 ethylenedioxythiophene) (PEDOT). The majority of the work conducted was therefore aimed at developing methods for patterning and processing...
Magnetically actuated micropumps
Yamahata, Christophe
2005-01-01
"Lab-On-a-Chip" (LOC) systems are intended to transpose complete laboratory instrumentations on the few square centimetres of a single microfluidic chip. With such devices the objective is to minimize the time and cost associated with routine biological analysis while improving reproducibility. At the heart of these systems, a fluid delivery unit controls and transfers tiny quantities of liquids enabling the biological assays. This explains the need for robust integrated micropumps as a preco...
Magnetically actuated micropumps
Yamahata, Christophe; Gijs, Martin
2007-01-01
"Lab-On-a-Chip" (LOC) systems are intended to transpose complete laboratory instrumentations on the few square centimetres of a single microfluidic chip. With such devices the objective is to minimize the time and cost associated with routine biological analysis while improving reproducibility. At the heart of these systems, a fluid delivery unit controls and transfers tiny quantities of liquids enabling the biological assays. This explains the need for robust integrated micropumps as a preco...
Design of an implantable micropump
Smal, Olivier; Merken, Patrick; Croquet, Vincent; Raucent, Benoît; Debongnie, Jean-François; Delchambre, Alain
2004-01-01
The implantable programmable micropump is an interesting solution to treat chronic diseases such as diabetes with regular micro-injections of medicine. However, current applications of micropumps are limited by their rather expensive cost. The challenge is therefore to develop a low cost alternative by reducing the number of parts and by simplifying the assembly. As the pump and its tank will be placed under the skin in order to increase comfort, such a system should be small and reliable. In...
Hansen, Thomas Steen
2008-01-01
In this thesis an all polymer micropump, and the fabrication method required to fabricate this, are examined. Polymer microfluidic. devices are of major scientific interest because they can combine complicated chemical and biological analys~s in cheap and disposable devices. The electrode system...... room techniques. The conductive blend was coated with a layer of photoresist, exposed and developed. The resulting pattern was etched in a reactive ion etcher, yielding a well defined patterned with a resolution of approximately 2 J..lm. This technique was utilised to fabricate an ac electroosmotic...... a new short chained polyurethane. The resolution of the inkjet printer was in the order of 200 J-tm. The inkjet printed pattern is compared with the agarose stamping technique in a setup where the conductivity perpendicular to the stretching direction is measured on two electrodes fabricated by the two...
Conventional ion sources generate energetic ion beams by accelerating the plasma-produced ions through a voltage drop at the extractor, and since it is usual that the ion beam is to propagate in a space which is at ground potential, the plasma source is biased at extractor voltage. For high ion beam energy the plasma source and electrical systems need to be raised to high voltage, a task that adds considerable complexity and expense to the total ion source system. The authors have developed a system which though forming energetic ion beams at ground potential as usual, operates with the plasma source and electronics at ground potential also. Plasma produced by a nearby source streams into a grided chamber that is repetitively pulsed from ground to high positive potential, sequentially accepting plasma into its interior region and ejecting it energetically. They call the device a peristaltic ion source. In preliminary tests they've produced nitrogen and titanium ion beams at energies from 1 to 40 keV. Here they describe the philosophy behind the approach, the test embodiment that they have made, and some preliminary results
Towards an Implantable, Low Flow Micropump That Uses No Power in the Blocked-Flow State
Dean G. Johnson
2016-06-01
Full Text Available Low flow rate micropumps play an increasingly important role in drug therapy research. Infusions to small biological structures and lab-on-a-chip applications require ultra-low flow rates and will benefit from the ability to expend no power in the blocked-flow state. Here we present a planar micropump based on gallium phase-change actuation that leverages expansion during solidification to occlude the flow channel in the off-power state. The presented four chamber peristaltic micropump was fabricated with a combination of Micro Electro Mechanical System (MEMS techniques and additive manufacturing direct write technologies. The device is 7 mm × 13 mm × 1 mm (<100 mm3 with the flow channel and exterior coated with biocompatible Parylene-C, critical for implantable applications. Controllable pump rates from 18 to 104 nL/min were demonstrated, with 11.1 ± 0.35 nL pumped per actuation at an efficiency of 11 mJ/nL. The normally-closed state of the gallium actuator prevents flow and diffusion between the pump and the biological system or lab-on-a-chip, without consuming power. This is especially important for implanted applications with periodic drug delivery regimens.
A Magnetic Micropump Based on Ferrofluidic Actuation
Lung-Ming Fu
2014-05-01
Full Text Available A circular ferrofluidic micropump for biomedical applications is proposed comprising two ferrofluidic plugs contained within a PMMA (Polymethyl-Methacrylate microchannel and driven by a rotating stepping motor. Orthogonal and tangent-type micropumps are developed. The circular ferrofluidic micropump chip is patterned using a commercially-available CO2 laser scriber. The operation of the micropump relies on the use of magnetically-actuated ferrofluidic plugs. The ferrofluid contacts the pumped fluid but is immiscible with it. The flow rate in the two types of proposed devices can be easily controlled by adjusting the rotational velocity of the stepping motor. Results show that a maximum flow rate of 128 μl/min is obtained using the tangent-type micropump with a channel width of 1000 μm and a rotational velocity of 10 rpm with zero pressure head.
Chandler, Joseph A. (Inventor)
1986-01-01
The instant invention is directed to a peristaltic pump for critical laboratory or hospital applications requiring precise flow rates over an extended period of time. Within the cylindrical barrel pump housing is a single-piece, molded, elastometric, cylindrical liner with a multiplicity of flattened helical channels created therein from one end of the liner to the other. Three cylindrical rollers rotate about the center axis of the pump around the inside surface of the liner selectively compressing the liner, and hence the helical channels between the rollers and the barrel housing, creating a pumping action by forcing trapped fluid in the helical channels axially from one end of the liner to the opposite end. The novelty of the invention appears to lie in the provision of the special liner with multiple helical channels as the pumping chamber, rather than the standard single elastomeric tubing which is squeezed repeatedly by rollers to move the liquid through a typical peristaltic pump. Large, repeated deflections on the standard tubing causes a permanent set in the tubing, thus either changing the flow rate, or requiring a new section of tubing to be positioned in the pump head. Further, this configuration minimizes the amount of outflow pulsation which is characteristic of a typical single tubing peristaltic pump.
Induction electrohydrodynamics micropump forhigh heat flux cooling
Singhal, Vishal; Garimella, S V
2007-01-01
Induction electrohydrodynamics (EHD) has been investigated as a possible means of pumping liquids through microchannel heat sinks for cooling microprocessors. A pump utilizing induction EHD has been microfabricated and tested. The experimental results matched the predictions from correlations to within 30%. Based on this, a micropump has been designed which is miniaturizable to a level where it can be integrated into the microchannels. The micropump utilizes a vibrating diaphragm along with i...
A Micropump Driven by Marangoni Effect
Sugimoto, Kenji; Iwamoto, Kaoru; Kawamura, Hiroshi
A micropump driven by the thermocapillary convection is proposed. The purpose of this study is to examine the flow structure in liquid region and the effect of the geometry on the performance of the present micropump. There are two significant advantages in the thermocapillary-driven system. First, the surface forces become more dominant than the volume forces with decreasing scale. The present micropump driven by the surface forces shows an advantage in the micro scale over a diaphragm pump driven by the volume forces. Secondary, the thermocapillary driven system contains no movable parts; thus, it allows a very simple structure compared to the diaphragm one. In the present micropump system, a number of ribs are distributed along the flow circuit between a heater and a cooler. Since heat transfer from these ribs to the working liquid imposes temperature gradients along the gas-liquid interfaces, the flow from the hot to the cold side is induced by the Marangoni effect. Fundamental characteristics of the present micropump are studied on the basis of three-dimensional simulation conducted taking the gas, liquid and ribs into account. In this study, the flow structure corresponding to the temperature field was observed. The present calculation has revealed that the flow field exhibits a transition from steady flow to oscillatory flow when the Marangoni number exceeds a critical value of about 2,000-2,500. An experiment was also performed. The liquid flow driven by the present micropump system was confirmed through the experiment.
Valveless micropump driven by acoustic streaming
This paper describes two valveless micropumps built on a 260 µm thick PZT with 20 µm thick parylene acoustic Fresnel lenses with air cavities. The micropumps produce in-plane body force through acoustic streaming effect of high-intensity acoustic beam that is generated by acoustic wave interference. The fabricated micropumps were shown to move microspheres, which have a diameter of 70–90 µm and a density of 0.99 g cm−3, on the water surface to form U-shape streams of microspheres with a drift velocity of 7.3 cm s−1 when the micropumps were located 4 mm below the water surface and driven by 160 Vpeak-to-peak pulsed sinusoidal waves. The driven microspheres formed U-shape streaming even without any fluidic channel according to the serial connection of the pie-shaped lenses and top electrodes. A micropump with a straight-lined fluidic channel was also fabricated and tested to show a 9.2 cm s−1 microspheres' drift velocity and a 9.5 mL min−1 volume pumping rate when combined with the acrylic acoustic wave reflector. Both the Fresnel lens and top electrode were patterned in a pie-shape with its apex angle of 90° to form asymmetric acoustic pressure distribution at the focal plane of the acoustic Fresnel lenses in order to push water in one direction. (paper)
Design,fabrication and experimental research for an electrohydrodynamic micropump
无
2010-01-01
This paper presented a novel electrohydrodynamic (EHD) micropump based on MEMS technology. The working mechanisms and classification of EHD micropump were introduced. The fabrication process of EHD micropump was presented with the material selection,optimal design of microelectrode and assembly process. Static pressure experiments and flow experiments were carried out using different fluid and the channel depth. The results indicated that the micropump could achieve a maximum static pressure head of 268 Pa at an applied voltage of 90 V. The maximum flow rate of the micropump-driven fluid could reach 106 μL/min. This paper analyzed the future of combining micropump with heat pipe to deal with heat dissipation of high power electronic chips. The maximum heat dissipation capacity of 87 W/cm2 can be realized by vaporizing the micropump-driven liquid on vaporizing section of the heat pipe.
Carbon Nanotube Amperometric Chips with Pneumatic Micropumps
Tsujita, Yuichi; Maehashi, Kenzo; Matsumoto, Kazuhiko; Chikae, Miyuki; Torai, Soichiro; Takamura, Yuzuru; Tamiya, Eiichi
2008-04-01
We fabricated carbon nanotube (CNT) amperometric chips with pneumatic micropumps by the combination of amperometric biosensors based on CNT-arrayed electrodes and microchannels with pneumatic micropumps made of poly(dimethylsiloxane). On the chip, phosphate buffer solution and potassium ferricyanide, K3[Fe(CN)6], were introduced into the CNT electrodes using each pneumatic micropump and electrochemically measured by differential pulse voltammetry. The results indicate that our chip can automatically exchange reagents on the CNT electrodes and clearly detect molecules. Moreover, by modifying the CNT electrodes with enzyme glucose oxidase, glucose molecules could be detected using our chips by cyclic voltammetry and chronoamperometry. We conclude that microfluidic chips with CNT-arrayed electrodes are a promising candidate for the development of hand-held electrochemical biosensors.
Performance characteristics of valveless and cantilever-valve micropump
Shukur, A. F. M.; Sabani, N.; Taib, B. N.; Azidin, M. A. M.; Shahimin, M. M.
2013-12-01
This paper presents comparison between two classes of micropump which are valveless micropump and cantilever-valve micropump. These micropumps consist of basic components which are diaphragm, pumping chamber, actuation mechanism, inlet and outlet. Piezoelectric actuation is carried out by applying pressure on the micropump diaphragm to produce deflection. The micropumps studied in this paper had been designed with specific diaphragm thickness and diameter; while varying the materials, pressure applied and liquid types used. The outer dimension for both micropumps is 4mm × 4mm × 0.5mm with diameter and thickness of the diaphragm are 3.8mm and 20μm respectively. Valveless micropump was shown in this paper to have better performance in mechanical and fluid analysis in terms of maximum deflection and maximum flow rate at actuation pressure 30kPa vis-à-vis cantilever-valve micropump. Valveless micropump was shown in this study to have maximum diaphragm deflection of 183.06μm and maximum flow rate with 191.635μL/s at actuation pressure 30kPa using silicon dioxide as material.
High precision innovative micropump for artificial pancreas
Chappel, E.; Mefti, S.; Lettieri, G.-L.; Proennecke, S.; Conan, C.
2014-03-01
The concept of artificial pancreas, which comprises an insulin pump, a continuous glucose meter and a control algorithm, is a major step forward in managing patient with type 1 diabetes mellitus. The stability of the control algorithm is based on short-term precision micropump to deliver rapid-acting insulin and to specific integrated sensors able to monitor any failure leading to a loss of accuracy. Debiotech's MEMS micropump, based on the membrane pump principle, is made of a stack of 3 silicon wafers. The pumping chamber comprises a pillar check-valve at the inlet, a pumping membrane which is actuated against stop limiters by a piezo cantilever, an anti-free-flow outlet valve and a pressure sensor. The micropump inlet is tightly connected to the insulin reservoir while the outlet is in direct communication with the patient skin via a cannula. To meet the requirement of a pump dedicated to closed-loop application for diabetes care, in addition to the well-controlled displacement of the pumping membrane, the high precision of the micropump is based on specific actuation profiles that balance effect of pump elasticity in low-consumption push-pull mode.
LIQUID-SOLID COUPLED SYSTEM OF MICROPUMP
Wu Jiankang; Lu Lijun
2006-01-01
This paper employs the integral-averaged method of thickness to approximate the periodical flows in a piezoelectric micropump, with a shallow water equation including nonlinearity and viscous damp presented to characterize the flows in micropump. The finite element method is used to obtain a matrix equation of fluid pressure. The fluid pressure equation is combined with the vibration equation of a silicon diaphragm to construct a liquid-solid coupled equation for reflecting the interaction between solid diaphragm and fluid motion in a micropump. Numerical results of a mode analysis of the coupled system indicate that the natural frequencies of the coupled system are much lower than those of the non-coupled system. The influence of additional mass and viscous damp of fluid on the natural frequencies of the coupled system is more significant as the pump thickness is small. It is found that the vibration shape functions of silicon diaphragm of the coupled system are almost the same as those of the non-coupled system. This paper also gives the first-order amplitude-frequency relationship of the silicon diaphragm, which is necessary for the flow-rate-frequency analysis of a micropump.
Modular Architecture of a Non-Contact Pinch Actuation Micropump
Ruzairi Abdul Rahim; Pei Ling Leow; Uda Hashim; Tijjani Adam; Rashidah Arsat; Pei Song Chee
2012-01-01
This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB) as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element a...
Surface micromachined electrostatically actuated micro peristaltic pump
Xie, Jun; Shih, Jason; Lin, Qiao; Yang, Bozhi; Tai, Yu-Chong
2004-01-01
An electrostatically actuated micro peristaltic pump is reported. The micro pump is entirely surface micromachined using a multilayer parylene technology. Taking advantage of the multilayer technology, the micro pump design enables the pumped fluid to be isolated from the electric field. Electrostatic actuation of the parylene membrane using both DC and AC voltages was demonstrated and applied to fluid pumping based on a 3-phase peristaltic sequence. A maximum flow rate of 1.7 nL min^–1 and a...
Wettability-gradient-driven micropump for transporting discrete liquid drops
In this paper, we report our efforts toward building a microelectromechanical system-based micropump. The micropump is driven by a wettability gradient and used to transport discrete drops. The gradient in wettability is distributed axisymmetrically, with hydrophobicity of the micropump surface decreasing radially toward the center. Both physical and chemical properties of the surface are altered to obtain the wettability gradient needed for driving the drops. The surface of the micropump is, first, patterned with pre-designed micro-features that define the roughness of the surface and, then, coated with a low-energy interface film. Results show that drops deposited on the surface of the micropump move, in a directional way, along the wettability gradient. The average velocity of the deposited drops is 5 mm s−1. Measured contact angles decrease gradually from 157.0° to 124.2° toward the center of the micropump surface. Maximum driving force exerted by the solid surface on the drops is 12.82 µN. The average size of the drops transported on the surface of the micropump is 2 µL. (paper)
Linear peristaltic pump based on electromagnetic actuators
Maddoui Lotfi
2014-01-01
Full Text Available In this paper a study and design of a linear peristaltic pump are presented. A set of electromagnetic (solenoid actuators is used as the active tools to drag the liquid by crushing an elastic tube. The pump consists of six serially-connected electromagnetic actuators controlled via an electronic board. This may be considered as a simulated peristalsis action of intestines. The dynamic performances of the pump are investigated analytically and experimentally.
Continuous dynamic flow micropumps for microfluid manipulation
Recent years have seen considerable progress in the development of microfabricated systems for use in the chemical and biological sciences. The term micro total analytical system (µTAS) is now a well-accepted concept. Much development has been driven by a need to perform effective manipulation of chemical and biological liquids with small volumes at micro and/or nano flowrate level in these systems. In this review, the focus will be on the pumping techniques used for delivery and control of liquids, especially those physical-chemical 'continuous dynamic flow micropumps'. The principles of these pumping techniques are mainly based on one or several well-known phenomena such as electrical, light, magnetic, thermal and other actuated mechanisms. Electrokinetically-driven continuous flow pumps such as the electrophoretic pump and electroosmotic pump, surface chemistry based continuous flow micropumps such as the opto-electrowetting-based pump, optically-driven pump, electrochemical pump and constant gravity-driven pump, and combination-driven techniques such as hydrodynamic flow and electrokinetic/gravity/magnetophoretic pumping will be summarized. The focus will be on the research highlights, trends and future of these pump techniques. Finally, mixing techniques on the microscale are briefly reviewed. (topical review)
The dynamic characteristics of a valve-less micropump
Jiang Dan; Li Song-Jing
2012-01-01
The aim of this paper is to investigate the dynamic characteristics of a valve-less micropump.A dynamic mathematical model of the micropump based on a hydraulic analogue system and a simulation method using AMESim software are developed.By using the finite-element analysis method,the static analysis of the diaphragm is carried out to obtain the maximum deflection and volumetric displacement.Dynamic characteristics of the valve-less micropump under different excitation voltages and frequencies are simulated and tested.Because of the discrepancy between simulation results and experimental data at frequencies other than the natural frequency,the revised model for the diaphragm maximum volumetric displacement is presented.Comparison between the simulation results based on the revised model and experimental data shows that the dynamic mathematical model based on the hydraulic analogue system is capable of predicting dynamic characteristics of the valve-less micropump at any excitation voltage and frequency.
A global assessment of piezoelectric actuated micro-pumps
Hernandez, C.; Bernard, Y; Razek, A.
2010-01-01
Abstract This article provides an extensive outlook of different types of piezoelectric actuated micro-pumps published in the literature recently. We start by reminding the reader about the conventional operating parameters used to quantify the capabilities of these devices. After this introductory stage, we describe and classify the most prominent micro-pump's geometries found with piezoelectric actuation. At this point we identify the parameters given ...
Design and modeling of a light powered biomimicry micropump
Sze, Tsun-kay Jackie; Liu, Jin; Dutta, Prashanta
2015-06-01
The design of compact micropumps to provide steady flow has been an on-going challenge in the field of microfluidics. In this work, a novel micropump concept is introduced utilizing bacteriorhodopsin and sugar transporter proteins. The micropump utilizes light energy to activate the transporter proteins, which create an osmotic pressure gradient and drive the fluid flow. The capability of the bio inspired micropump is demonstrated using a quasi 1D numerical model, where the contributions of bacteriorhodopsin and sugar transporter proteins are taken care of by appropriate flux boundary conditions in the flow channel. Proton flux created by the bacteriorhodopsin proteins is compared with experimental results to obtain the appropriate working conditions of the proteins. To identify the pumping capability, we also investigate the influences of several key parameters, such as the membrane fraction of transporter proteins, membrane proton permeability and the presence of light. Our results show that there is a wide bacteriorhodopsin membrane fraction range (from 0.2 to 10%) at which fluid flow stays nearly at its maximum value. Numerical results also indicate that lipid membranes with low proton permeability can effectively control the light source as a method to turn on/off fluid flow. This capability allows the micropump to be activated and shut off remotely without bulky support equipment. In comparison with existing micropumps, this pump generates higher pressures than mechanical pumps. It can produce peak fluid flow and shutoff head comparable to other non-mechanical pumps.
Peristaltic pumps work in nano scales
Farahpour, Farnoush; Ejtehadi, Mohammad Reza
2013-01-01
A design for a pump is suggested which is based on well-known peristaltic pumps. In order to simply describe the operation of the proposed pump, an innovative interpretation of low Reynolds number swimmers is presented and thereafter a similar theoretical model would be suggested to quantify the behavior of the pumps. A coarse-grained molecular dynamic simulation is used to examine the theoretical predictions and measure the efficiency of the pump in nano scales. It is shown that this pump wi...
Peristaltic Transport through Eccentric Cylinders: Mathematical Model
Kh. S. Mekheimer
2013-01-01
Full Text Available This paper discusses the effect of peristaltic transport on the fluid flow in the gap between two eccentric tubes (eccentric-annulus flows. The inner tube is uniform, rigid, while the outer tube has a sinusoidal wave traveling down its wall. The flow analysis has been developed for low Reynolds number and long wave length approximation. The velocity and the pressure gradient have been obtained in terms of the dimensionless flow rate Q¯, time t, azimuthal coordinate θ and eccentricity parameter ϵ (the parameter that controls of the eccentricity of the inner tube position. The results show that there is a significant deference between eccentric and concentric annulus flows.
Geometrical tuning of microdiffuser/nozzle for valveless micropumps
Valveless micropumps require the integration of microdiffusers/nozzles for flow rectification in microfluidic systems. The flow directing capability of a micropump is determined by the efficiency of the diffuser. With the reduction in size of the micropump, conventional microdiffuser geometrical parameters are not suitable for obtaining high flow efficiencies due to several fluidic effects such as channel friction, wall shear stress, vena contracta, etc, and therefore it is important to modify the diffuser geometry according to the requirements of the pressure coefficients in order to obtain improved flow rates. This paper presents a simple and microfabrication friendly geometrical tuning method which offers the user a broad range of dependent tunable geometric parameters to improve the performance of the microdiffuser for valveless micropumps. Herein, for a given flow condition, the flow behaviour and the variation of pressure coefficients of the microdiffuser/nozzle with geometric tuning have been studied for different diffuser angles using finite element modelling (FEM). The results show that the proposed method is highly suitable for tuning the geometry of microdiffusers for a wide range of operating conditions of valveless micropumps. The performances of the best diffuser geometries for different diffuser angles have been experimentally verified, and the test results are used for the validation of the results of the FEM. The comparison between the FEM and experimental results shows a close agreement.
Piezoelectric diffuser/nozzle micropump with double pump chambers
Wei WANG; Ying ZHANG; Li TIAN; Xiaojie CHEN; Xiaowei LIU
2008-01-01
To eliminate check valve fatigue and valve clogging, diffuser/nozzle elements are used for flow rec-tification in a valveless diffuser/nozzle micropump instead of valves. However, the application of this type of micro-pump is restricted because of its pulsating or periodic flow and low pump flux. In this paper, a diffuser/nozzle Si/ Glass micropump with two pump chambers by IC and MEMS technology is designed. The fabrication process requires only one mask and one etch step, so that the fabrication has the advantages of low cost, short proces-sing period, and facilitation of miniaturization. The pump is equipped with a glass cover board so as to conveniently observe the flow status. Pump-chambers and diffuser ele-ments are fabricated by the anisotropic KOH-etch tech-nique on the silicone substrate, and the convex corner is designed to compensate for an anisotropic etch. The driv-ing force of the micropump is produced by the PZT piezo-electric actuator, The pump performance with both actuators actuated in anti- or same-phase mode is also researched. The result indicates that the micropump achieves great performance with the actuators working at anti-phase. This may be because the liquid flows stead-ily, pulse phenomenon is very weak, and the optimal working frequency, pump back pressure, and flow rate are both double that of the pump driven in same-phase.
A linear peristaltic MRF/foam actuator
Larsen, J. J.; Jenkins, C. H.; Korde, U. A.
2007-04-01
, peristaltic pumps in industry are common for a variety of material handling applications, particularly involving the movement of sterile fluids (for example, blood). The peristaltic pump is usually circular in configuration, relying on external rollers to move fluid within a tube. Some linear configuration pumps have been proposed and developed, however they are complicated than their circular counterparts. In the remaining part of the present work, we discuss the development of a linear peristaltic actuator based upon the deformation of MRF/foam. The actuator consists of an open-cell polymer foam substrate infused with MRF. To one side of the foam substrate resides a translating magnet, such that a magnetic field can be propagated down its length. The linear peristaltic action is generated as the transversely propagating field shapes the MRF/foam substrate in a corresponding way. Experimental results are discussed, an outline of on-going theoretical modeling is presented, and conclusions are provided.
Swimming and peristaltic pumping between two plane parallel walls
Swimming at low Reynolds number in a fluid confined between two plane walls is studied for an infinite plane sheet located midway between the walls and distorted with a transverse propagating wave. It is shown that the flow pattern is closely related to that for peristaltic pumping. The hydrodynamic interaction between two flexible sheets swimming parallel in infinite space is related to the problem of peristaltic pumping in a planar channel with two wavy walls.
Analysis, design and experimental characterization of electrostatically actuated gas micropumps
Astle, Aaron A.
This work goal is to realize a high-performance, multi-stage micropump integrated within a wireless micro gas chromatograph (muGC) for measuring airborne environment pollutants. The work described herein focuses on the development of high-fidelity mathematical and physical design models, and the testing and validation of the most promising models with large-scale and micro-scale (MEMS) pump prototypes. It is shown that an electrostatically-actuated, multistage, diaphragm micropump with active valve control provides the best expected performance for this application. A hierarchy of models is developed to characterize the various factors governing micropump performance. This includes a thermodynamic model, an idealized reduced-order model and a reduced-order model that incorporates realistic valve flow effects and accounts for fluidic load. The reduced-order models are based on fundamental fluid dynamic principles and allow predictions of flow rate and pressure rise as a function of geometric design variables, and drive signal. The reduced order models are validated in several tests. Two-stage, 20x scale pump results reveal the need to incorporate realistic valve flow effects and the output load for accurate modeling. The more realistic reduced order model is then validated using micropumps with two and four pumping stages. The reduced order model captures the micropump performance accurately, provided that separate measurements of valve pressure losses and pump geometry are used. The four-stage micropump fabricated using theoretical model guidelines from this research provides a maximum flow rate and pressure rise of 3 cm 3/min and 1.75 kPa/stage respectively with a power consumption of only 4 mW per stage. The four-stage micropump occupies and area of 54 mm 2. Each pumping cavity has a volume of 6x10-6 m 3. This performance indicates that this pump design will be sufficient to meet the requirements for extended field operation of a wireless integrated muGC. During
Valveless Thermally-Driven Phase-Change Micropump
王沫然; 李志信
2004-01-01
A dynamic model with moving heat sources was developed to analyze the pumping mechanism of a valveless thermally-driven phase-change micropump. The coupled equations were solved to determine the pumping characteristics. The numerical results agree with experimental data from micropumps with different diameter microtubes. The maximum flow rate reached 33 μL / min and the maximum pump pressure was over 20 kPa for a 200-μm diameter microtube. Analysis of the pumping mechanism shows that the main factors affecting the flow come from the large density difference between the liquid and vapor phases and the choking effect of the vapor region.
Modular Architecture of a Non-Contact Pinch Actuation Micropump
Ruzairi Abdul Rahim
2012-09-01
Full Text Available This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element analysis (FEA. The micropump was evaluated against two frequency ranges, which comprised a low driving frequency range (0–5 Hz, with 0.5 Hz step increments and a nominal frequency range (0–80 Hz, with 10 Hz per step increments. The low range frequency features a linear relationship of flow rate with the operating frequency function, while two magnitude peaks were captured in the flow rate and back pressure characteristic in the nominal frequency range. Repeatability and reliability tests conducted suggest the pump performed at a maximum flow rate of 5.78 mL/min at 65 Hz and a backpressure of 1.35 kPa at 60 Hz.
A high current density DC magnetohydrodynamic (MHD) micropump
Homsy, Alexandra; Koster, Sander; Eijkel, Jan C.T.; Berg, van den Albert; Lucklum, F.; Verpoorte, E.; Rooij, de Nico F.
2005-01-01
This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-µm-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a micromachined
A high current density DC magnetohydrodynamic (MHD) micropump
Homsy, A; Koster, Sander; Eijkel, JCT; van den Berg, A; Lucklum, F; Verpoorte, E; de Rooij, NF
2005-01-01
This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-mu m-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a micromachin
Optofluidic modulator based on peristaltic nematogen microflows
Cuennet, J. G.; Vasdekis, A. E.; de Sio, L.; Psaltis, D.
2011-04-01
Nematogens rotate by the application of external fields, thereby enabling optical modulation. This principle has had a profound impact on our daily lives through the plethora of liquid-crystal displays in use around us. However, the wider use of nematic liquid crystals, particularly in microdisplays and information processing, has been hampered by their slow response times. In nematogens, rotational and translational molecular motions are coupled, so flow is inevitably linked with optical modulation. This linkage motivated us to fuse microfluidics with anisotropic liquids and introduce an optofluidic modulator that exhibits a submillisecond (250 µs) symmetric response and can operate at frequencies up to 1 kHz. The modulator is based on peristaltic nematogen microflows realized in polydimethylsiloxane microfluidics. The latter simultaneously permits peristalsis by means of elastomeric deformation, nematogen alignment and rapid prototyping through cast-moulding. Together with large-scale, vertical integration and piezoelectric nanotechnologies, this optofluidic paradigm can enable high-density and three-dimensional architectures of fast modulators.
A magnetically driven PDMS micropump with ball check-valves
Pan, Tingrui; McDonald, Scott J.; Kai, Eleanor M.; Ziaie, Babak
2005-05-01
In this paper, we present a low-cost, PDMS-membrane micropump with two one-way ball check-valves for lab-on-a-chip and microfluidic applications. The micropump consists of two functional PDMS layers, one holding the ball check-valves and an actuating chamber, and the other covering the chamber and holding a miniature permanent magnet on top for actuation. An additional PDMS layer is used to cover the top magnet, and thereby encapsulate the entire device. A simple approach was used to assemble a high-performance ball check-valve using a micropipette and heat shrink tubing. The micropump can be driven by an external magnetic force provided by another permanent magnet or an integrated coil. In the first driving scheme, a small dc motor (6 mm in diameter and 15 mm in length) with a neodymium-iron-boron permanent magnet embedded in its shaft was used to actuate the membrane-mounted magnet. This driving method yielded a large pumping rate with very low power consumption. A maximum pumping rate of 774 µL min-1 for deionized water was achieved at the input power of 13 mW, the highest pumping rate reported in the literature for micropumps at such power consumptions. Alternatively, we actuated the micropump with a 10-turn planar coil fabricated on a PC board. This method resulted in a higher pumping rate of 1 mL min-1 for deionized water. Although more integratable and compact, the planar microcoil driving technique has a much higher power consumption.
Dielectric elastomer peristaltic pump module with finite deformation
Mao, Guoyong; Huang, Xiaoqiang; Liu, Junjie; Li, Tiefeng; Qu, Shaoxing; Yang, Wei
2015-07-01
Inspired by various peristaltic structures existing in nature, several bionic peristaltic actuators have been developed. In this study, we propose a novel dielectric elastomer peristaltic pump consisting of short tubular modules, with the saline solution as the electrodes. We investigate the performance of this soft pump module under hydraulic pressure and voltage via experiments and an analytical model based on nonlinear field theory. It is observed that the individual pump module undergoes finite deformation and may experience electromechanical instability during operations. The driving pressure and displaced volume of the peristaltic pump module can be modulated by applied voltage. The efficiency of the pump module is enhanced by alternating current voltage, which can suppress the electromechanical pull-in instability. An analytical model is developed within the framework of the nonlinear field theory, and its predictive capacity is checked by experimental observations. The effects of the prestretch, aspect ratio, and voltage on the performance of the pump modules are characterized by the analytical model. This work can guide the designs of soft active peristaltic pumps in the field of artificial organs and industrial conveying systems.
Optimization design of multi-material micropump using finite element method
Zhu, Meiling; Kirby, Paul B.; Wacklerle, M.; Herz, M; Richter, M.
2009-01-01
This paper presents a micropump fabricated from low-cost materials with specific goal of cost reduction. The micropump does not require any valve flap and comprises of one plastic pump polyether-ether-ketone (PEEK) body, one metal diaphragm, and three piezoelectric ceramics to form piezoelectrically actuated diaphragm valves. The valve actuation simplifies micropump structural designs and assembly processes to make the pump attractive for low cost bio-medical drug delivery a...
Postprandial transduodenal bolus transport is regulated by complex peristaltic sequence
Huan Nam Nguyen; Ron Winograd; Gerson Ricardo Souza Domingues; Frank Lammert
2006-01-01
AIM: To study the relationship between the patterns of postprandial peristalsis and transduodenal bolus transport in healthy subjects.METHODS: Synchronous recording of chyme transport and peristaltic activity was performed during the fasting state and after administration of a test meal using a special catheter device with cascade configuration of impedance electrodes and solid-state pressure transducers. The catheter was placed into the duodenum,where the first channel was located in the first part of the duodenum and the last channel at the duodenojejunal junction. After identification of previously defined chyme transport patterns the associated peristaltic patterns were analyzed.RESULTS: The interdigestive phase 3 complex was reliably recorded with both techniques. Of 497 analyzed impedance bolus transport events, 110 (22%) were short-spanned propulsive, 307 (62%) long-spanned propulsive, 70 (14%)complex propulsive, and 10 (2%) retrograde transport.Short-spanned chyme transports were predominantly associated with stationary or propagated contractions propagated over short distance. Long-spanned and complex chyme transports were predominantly associated with propulsive peristaltic patterns, which were frequently complex and comprised multiple contractions. Propagated double wave contraction, propagated contraction with a clustered contraction, and propagated cluster of contractions have been identified to be an integralted part of a peristaltic sequence in human duodenum.CONCLUSION: Combined impedancometry andmanometry improves the analysis of the peristaltic patterns that are associated with postprandial transduodenal chyme transport. Postprandial transduodenal bolus transport is regulated by propulsive peristaltic patterns, which are frequently complex but well organized. This finding should be taken into consideration in the analysis of intestinal motility studies.
Heat Transfer Analysis for Peristaltic Mechanism in Variable Viscosity Fluid
T.Hayat; F.M.Abbasi; Awatif A.Hendi
2011-01-01
An analysis is carried out for a peristaltic flow of a third-order fluid with heat transfer and variable viscosity when no-slip condition does not hold. Perturbation solution is discussed and a comparative study between the cases of constant and variable viscosities is presented and analyzed.%@@ An analysis is carried out for a peristaltic flow of a third-order fluid with heat transfer and variable viscosity when no-slip condition does not hold.Perturbation solution is discussed and a comparative stuity between the cases of constant and variable viscosities is presented and analyzed.
Concepts for a new class of all-polymer micropumps.
Loverich, Jacob J; Kanno, Isaku; Kotera, Hidetoshi
2006-09-01
This paper presents a polymer-based micropump addressing the cost, performance, and system compatibility issues that have limited the integration of on-chip micropumps into microanalysis systems. This pump uses dielectric elastomer actuation to periodically displace fluid, and a pair of elastomeric check valves to rectify the fluid's resulting movement. Its significant features include the use of a transparent substrate, self-priming capability, insensitivity to gas bubbles, and the ability to admit particles. A pump occupying less than 10 mm2 of chip space produced a 77 microl min(-1) flow rate. The pump has a high thermodynamic efficiency and exhibits little performance degradation over 10 hours of operation. In addition to its notable performance, the pump can be fabricated at low cost and directly integrated into microfluidic chips that use planar softlithography-formed structures. The new pump concept, fabrication, and experimental performance are discussed herein. PMID:16929393
A novel reciprocating micropump based on Lorentz force
Salari, Alinaghi; Hakimsima, Abbas; Shafii, Mohammad Behshad
2015-03-01
Lorentz force is the pumping basis of many electromagnetic micropumps used in lab-on-a-chip. In this paper a novel reciprocating single-chamber micropump is proposed, in which the actuation technique is based on Lorentz force acting on an array of microwires attached on a membrane surface. An alternating current is applied through the microwires in the presence of a magnetic field. The resultant force causes the membrane to oscillate and pushes the fluid to flow through microchannel using a ball-valve. The pump chamber (3 mm depth) was fabricated on a Polymethylmethacrylate (PMMA) substrate using laser engraving technique. The chamber was covered by a 60 μm thick hyper-elastic latex rubber diaphragm. Two miniature permanent magnets capable of providing magnetic field of 0.09 T at the center of the diaphragm were mounted on each side of the chamber. Square wave electric current with low-frequencies was generated using a function generator. Cylindrical copper microwires (250 μm diameter and 5 mm length) were attached side-by-side on top surface of the diaphragm. Thin loosely attached wires were used as connectors to energize the electrodes. Due to large displacement length of the diaphragm (~3 mm) a high efficiency (~90%) ball valve (2 mm diameter stainless steel ball in a tapered tubing structure) was used in the pump outlet. The micropump exhibits a flow rate as high as 490 μl/s and pressure up to 1.5 kPa showing that the pump is categorized among high-flow-rate mechanical micropumps.
Peristaltic pump-based low range pressure sensor calibration system
Vinayakumar, K. B.; Naveen Kumar, G.; Nayak, M. M.; Dinesh, N. S.; Rajanna, K.
2015-11-01
Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.
Peristaltic pump-based low range pressure sensor calibration system
Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory
Long Wavelength Peristaltic Transport of Non-Newton Fluids
Devanathan, R; Parvathamma, S.
1980-01-01
Solutions are obtained for the stream function and the pressure field for the flow of non-Newtonian fluids in a tube by long peristaltic waves of arbitrary shape. The axial velocity profiles and stress distributions on the wall are discussed for particular waves of some practical interest. The effect of non- Newtonian character of the fluid is examined.
Electroosmosis-modulated peristaltic transport in microfluidic channels
Bandopadhyay, Aditya; Tripathi, Dharmendra; Chakraborty, Suman
2016-05-01
We analyze the peristaltic motion of aqueous electrolytes altered by means of applied electric fields. Handling electrolytes in typical peristaltic channel material such as polyvinyl chloride and Teflon leads to the generation of a net surface charge on the channel walls, which attracts counter-ions and repels co-ions from the aqueous solution, thus leading to the formation of an electrical double layer—a region of net charges near the wall. We analyze the spatial distribution of pressure and wall shear stress for a continuous wave train and single pulse peristaltic wave in the presence of an electrical (electroosmotic) body force, which acts on the net charges in the electrical double layer. We then analyze the effect of the electroosmotic body force on the particle reflux as elucidated through the net displacement of neutrally buoyant particles in the flow as the peristaltic waves progress. The impact of combined electroosmosis and peristalsis on trapping of a fluid volume (e.g., bolus) inside the travelling wave is also discussed. The present analysis goes beyond the traditional analysis, which neglects the possibility of coupling the net pumping of fluids due to peristalsis and allows us to derive general expressions for the pressure drop and flow rate in order to set up a general framework for incorporating flow control and actuation by simultaneous peristalsis and application of electric fields to aqueous solutions. It is envisaged that the results presented here may act as a model for the design of lab-on-a-chip devices.
Peristaltic pump-based low range pressure sensor calibration system.
Vinayakumar, K B; Naveen Kumar, G; Nayak, M M; Dinesh, N S; Rajanna, K
2015-11-01
Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory. PMID:26628178
Peristaltic pump-based low range pressure sensor calibration system
Vinayakumar, K. B. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 5600012 (India); Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 5600012 (India); Naveen Kumar, G.; Rajanna, K., E-mail: kraj@isu.iisc.ernet.in, E-mail: krajanna2011@gmail.com [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 5600012 (India); Nayak, M. M. [Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 5600012 (India); Dinesh, N. S. [Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 5600012 (India)
2015-11-15
Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.
SU8 diaphragm micropump with monolithically integrated cantilever check valves.
Ezkerra, Aitor; Fernández, Luis José; Mayora, Kepa; Ruano-López, Jesús Miguel
2011-10-01
This paper presents a SU8 unidirectional diaphragm micropump with embedded out-of-plane cantilever check valves. The device represents a reliable and low-cost solution for integration of microfluidic control in lab-on-a-chip devices. Its planar architecture allows monolithic definition of its components in a single step and potential integration with previously reported PCR, electrophoresis and flow-sensing SU8 microdevices. Pneumatic actuation is applied on a PDMS diaphragm, which is bonded to the SU8 body at wafer level, further enhancing its integration and mass production capabilities. The cantilever check valves move synchronously with the diaphragm, feature fast response (10ms), low dead volume (86nl) and a 94% flow blockage up to 300kPa. The micropump achieves a maximum flow rate of 177 μl min(-1) at 6 Hz and 200 kPa with an effective area of 10 mm(2). The device is reliable, self-priming and tolerant to particles and big bubbles. To the knowledge of the authors, this is the first micropump in SU8 with monolithically integrated cantilever check valves. PMID:21853192
A polymer chip-integrable piezoelectric micropump with low backpressure dependence
Conde, A. J.; Bianchetti, A.; Veiras, F. E.;
2015-01-01
We describe a piezoelectric micropump constructed in polymers with conventional machining methods. The micropump is self-contained and can be built as an independent device or as an on-chip module within laminated microfluidic chips. We demonstrate on-chip integrability by the fabrication...
Kumar, N.; George, D.; Sajeesh, P.; Manivannan, P. V.; Sen, A. K.
2016-07-01
We report a planar solenoid actuated valveless micropump with multiple inlet–outlet configurations. The self-priming characteristics of the multiple inlet–multiple outlet micropump are studied. The filling dynamics of the micropump chamber during start-up and the effects of fluid viscosity, voltage and frequency on the dynamics are investigated. Numerical simulations for multiple inlet–multiple outlet micropumps are carried out using fluid structure algorithm. With DI water and at 5.0 Vp-p, 20 Hz frequency, the two inlet–two outlet micropump provides a maximum flow rate of 336 μl min‑1 and maximum back pressure of 441 Pa. Performance characteristics of the two inlet–two outlet micropump are studied for aqueous fluids of different viscosity. Transport of biological cell lines and diluted blood samples are demonstrated; the flow rate-frequency characteristics are studied. Viability of cells during pumping with multiple inlet multiple outlet configuration is also studied in this work, which shows 100% of cells are viable. Application of the proposed micropump for simultaneous pumping, mixing and distribution of fluids is demonstrated. The proposed integrated, standalone and portable micropump is suitable for drug delivery, lab-on-chip and micro-total-analysis applications.
A Numerical Investigation of Peristaltic Waves in Circular Tubes
Xiao, Q.; Damodaran, M.
Peristaltic pumping is a process of fluid transport arising from the progressive waves, which travel along the walls of a flexible channel. It is a primary physiological transport mechanism that is inherent in many tubular organs of the human body such as the ureter, the gastro-intestinal tract, the urethra, and so on. Many studies exist in literature with the aim of understanding the characteristics of peristaltic flow under the assumption of low Reynolds number and infinitely long wavelength in a two-dimensional channel. However, peristaltic pumping is also the mechanism used in other industrial applications such as the blood pump for which the Reynolds number has a moderately high value. As studies concerning moderate to high Reynolds number flow in the circular tube are rare in literature, in the present study, the peristaltic flow of an incompressible fluid is numerically simulated using the finite volume method for solving the incompressible Navier-Stokes equations in primitive variable formulation by means of an infinite train of sinusoidal waves traveling along the wall of an axi-symmetric tube. The computational model presented in this work covers a wider range of Reynolds number (0.01-100), wave amplitude (0-0.8), and wavelength (0.01-0.4) than the those attempted in previous studies reported in literature and some new results pertaining to the distribution of velocity, pressure, wall shear stress for different peristaltic flow conditions characterizing flow at moderately higher Reynolds number have been obtained. The effect of the wave amplitude, wavelength, and Reynolds number on the "flow trapping" mechanism induced by peristalsis has also been investigated here for higher ranges of values of the parameters characterizing peristalsis.
A modeling and vibration analysis of a piezoelectric micro-pump diaphragm
Kaviani, Samira; Bahrami, Mohsen; Esfahani, Amir Monemian; Parsi, Behzad
2014-12-01
The vibration analysis of a micro-pump diaphragm is presented. A piezoelectric micro-pump is studied. For this purpose, a dynamic model of the micro-pump is derived. The micro-pump diaphragm is modeled as circular double membranes, a piezoelectric one as actuator and a silicon one for representing the membrane for pumping action. The damping effect of the fluid is introduced into the equations. Vibration analysis is established by explicitly solving the dynamic model. The natural frequencies and mode shapes are calculated. The orthogonality conditions of the system are discussed. To verify the results, the finite-element micro-pump model is developed in ANSYS software package. The results show that the two methods are well comparable.
Pneumatically Actuated Miniature Peristaltic Vacuum Pumps
Feldman, Sabrina; Feldman, Jason; Svehla, Danielle
2003-01-01
Pneumatically actuated miniature peristaltic vacuum pumps have been proposed for incorporation into advanced miniature versions of scientific instruments that depend on vacuum for proper operation. These pumps are expected to be capable of reaching vacuum-side pressures in the torr to millitorr range (from .133 down to .0.13 Pa). Vacuum pumps that operate in this range are often denoted roughing pumps. In comparison with previously available roughing pumps, these pumps are expected to be an order of magnitude less massive and less power-hungry. In addition, they would be extremely robust, and would operate with little or no maintenance and without need for oil or other lubricants. Portable mass spectrometers are typical examples of instruments that could incorporate the proposed pumps. In addition, the proposed pumps could be used as roughing pumps in general laboratory applications in which low pumping rates could be tolerated. The proposed pumps could be designed and fabricated in conventionally machined and micromachined versions. A typical micromachined version (see figure) would include a rigid glass, metal, or plastic substrate and two layers of silicone rubber. The bottom silicone layer would contain shallow pump channels covered by silicone arches that could be pushed down pneumatically to block the channels. The bottom silicone layer would be covered with a thin layer of material with very low gas permeability, and would be bonded to the substrate everywhere except in the channel areas. The top silicone layer would be attached to the bottom silicone layer and would contain pneumatic- actuation channels that would lie crosswise to the pump channels. This version is said to be micromachined because the two silicone layers containing the channels would be fabricated by casting silicone rubber on micromachined silicon molds. The pneumatic-actuation channels would be alternately connected to a compressed gas and (depending on pump design) either to atmospheric
Magnetic cantilever actuator with sharpened magnetic thin film ellipses
Huang, Chen-Yu; Ger, Tzong-Rong; Lai, Mei-Feng; Chen, We-Yun; Huang, Hao-Ting; Chen, Jiann-Yeu; Wang, Pei-Jen; Wei, Zung-Hang
2015-05-01
A SiO2 cantilever covered by elliptical magnetic thin films was designed as an actuator. Under magnetic field, the elliptical magnetic film with sharp ends would exhibit single-domain structures and generate torque to push or pull the two arms of the cantilever. The cantilever could then stretch or compress and the displacement could be controlled by adjusting the magnitude and direction of the external magnetic field. The combination between micromagnetism of patterned films and actuator was successfully demonstrated. The magnetic actuator can be applied for future application in the biological field and would be valuable for microelectromechanical systems (MEMS).
Vibration analysis of magnetostrictive thin-film composite cantilever actuator
Xu, Yan; Shang, Xinchun
2016-09-01
The transverse vibration of a composed cantilever beam with magnetostrictive layer is analyzed, which is employed to simulate dynamic response of an actuator. The high-order shear deformation theory of beam and the coupling magnetoelastic constitutive relationship are introduced to construct the governing equations, all interface conditions between magnetostrictive film and elastic substrate as well as the free stress condition on the top and bottom surfaces of the beam can be satisfied. In order to demonstrate validity of the presented mathematical modeling, the verification examples are also given. Furthermore, the effect of geometry and material parameters on dynamic characteristics of magnetostrictive cantilever beam, such as the nature frequency and amplitude, is discussed. Moreover, through computing the magneto-mechanical coupling factor of the beam structure, the variation tendency curves of the factor along with different parameters and frequencies of magnetostrictive cantilever beam actuator have been presented. These numerical results should be useful for the design of beam-type with magnetostrictive thin-film actuators.
DESIGN AND OPTIMIZATION OF VALVELESS MICROPUMPS BY USING GENETIC ALGORITHMS APPROACH
AIDA F. M. SHUKUR
2015-10-01
Full Text Available This paper presents a design optimization of valveless micropump using Genetic Algorithms (GA. The micropump is designed with a diaphragm, pumping chamber and diffuser/nozzle element functions as inlet and outlet of micropump with outer dimension of (5×1.75×5 mm3. The main objectives of this research are to determine the optimum pressure to be applied at micropump’s diaphragm and to find the optimum coupling parameters of the micropump to achieve high flow rate with low power consumption. In order to determine the micropump design performance, the total deformation, strain energy density, equivalent stress for diaphragm, velocity and net flow rate of micropump are investigated. An optimal resonant frequency range for the diaphragm of valveless micropump is obtained through the result assessment. With the development of GA-ANSYS model, a maximum total displacement of diaphragm, 5.3635 µm, with 12 kPa actuation pressure and optimum net flowrate of 7.467 mL/min are achieved.
Effects of Magnetic Field and an Endoscope on Peristaltic Motion
V. P. Rathod
2011-01-01
Full Text Available The Problem of peristaltic transport of a magnetic fluid with variable viscosity through the gap between coaxial tubes where the outer tube is nonuniform with sinusoidal wave traveling down its wall and the inner tube is rigid. The relation between the pressure gradient and friction force on the inner and outer tubes is obtained in terms of magnetic and viscosity parameter. The numerical solutions of pressure gradient, outer friction and inner friction force, and flow rate are shown graphically.
Peristaltic particle transport using the Lattice Boltzmann method
Connington, Kevin William [Los Alamos National Laboratory; Kang, Qinjun [Los Alamos National Laboratory; Viswanathan, Hari S [Los Alamos National Laboratory; Abdel-fattah, Amr [Los Alamos National Laboratory; Chen, Shiyi [JOHNS HOPKINS UNIV.
2009-01-01
Peristaltic transport refers to a class of internal fluid flows where the periodic deformation of flexible containing walls elicits a non-negligible fluid motion. It is a mechanism used to transport fluid and immersed solid particles in a tube or channel when it is ineffective or impossible to impose a favorable pressure gradient or desirous to avoid contact between the transported mixture and mechanical moving parts. Peristaltic transport occurs in many physiological situations and has myriad industrial applications. We focus our study on the peristaltic transport of a macroscopic particle in a two-dimensional channel using the lattice Boltzmann method. We systematically investigate the effect of variation of the relevant dimensionless parameters of the system on the particle transport. We find, among other results, a case where an increase in Reynolds number can actually lead to a slight increase in particle transport, and a case where, as the wall deformation increases, the motion of the particle becomes non-negative only. We examine the particle behavior when the system exhibits the peculiar phenomenon of fluid trapping. Under these circumstances, the particle may itself become trapped where it is subsequently transported at the wave speed, which is the maximum possible transport in the absence of a favorable pressure gradient. Finally, we analyze how the particle presence affects stress, pressure, and dissipation in the fluid in hopes of determining preferred working conditions for peristaltic transport of shear-sensitive particles. We find that the levels of shear stress are most hazardous near the throat of the channel. We advise that shear-sensitive particles should be transported under conditions where trapping occurs as the particle is typically situated in a region of innocuous shear stress levels.
Augmentation of peristaltic microflows through electro-osmotic mechanisms
The present work aims to theoretically establish that the employment of an axial electric field can substantially augment the rate of microfluidic transport occurring in peristaltic microtubes. For theoretical analysis, shape evolution of the tube is taken to be arbitrary, except for the fact that the characteristic wavelength is assumed to be significantly greater than the average radius of cross section. First, expressions for the velocity profile within the tube are derived and are subsequently utilized to obtain variations in the net flow rate across the same, as a function of the pertinent system parameters. Subsequently, the modes of interaction between the electro-osmotic and peristaltic mechanisms are established through the variations in the time-averaged flow rates for zero pressure rise and the pressure rise for zero time-averaged flow rates, as expressed in terms of the occlusion number, characteristic electro-osmotic velocity and the peristaltic wave speed. From the simulation predictions, it is suggested that a judicious combination of peristalsis and an axial electrokinetic body force can drastically enhance the time-averaged flow rate, provided that the occlusion number is relatively small
Metal additive manufacturing of a high-pressure micro-pump
Wits, Wessel W.; Weitkamp, Sander J.; Es, van, J.M.
2013-01-01
For the thermal control of future space applications pumped two-phase loops are an essential part to handle the increasing thermal power densities. This study investigates the design of a reliable, leak tight, low-weight and high-pressure micro-pump for small satellite applications. The developed micro-pump uses a piezoelectric disk to create a pressure head and propel the working fluid. The micro-pumps are produced from Titanium alloy (Ti6Al4 V) using Selective Laser Melting (SLM) as a metal...
A dynamic model of valveless micropumps with a fluid damping effect
A simple fluid–diaphragm coupling model for studying the dynamic performance of valveless micropumps is presented. The model includes fluid inertia and a squeeze film effect by solving the coupling equation simultaneously with the Reynolds equation. The model is validated with a valveless diffuser micropump actuated by either a piezoelectric or electromagnetic diaphragm. The performance of the pump is considered for pumping liquid and air. The resonant frequency and dynamic performance of the micropumps obtained by the model are in good agreement with the experimental data. The model can predict well the damping behavior of the pump.
A dynamic model of valveless micropumps with a fluid damping effect
Dinh, T. X.; Ogami, Y.
2011-11-01
A simple fluid-diaphragm coupling model for studying the dynamic performance of valveless micropumps is presented. The model includes fluid inertia and a squeeze film effect by solving the coupling equation simultaneously with the Reynolds equation. The model is validated with a valveless diffuser micropump actuated by either a piezoelectric or electromagnetic diaphragm. The performance of the pump is considered for pumping liquid and air. The resonant frequency and dynamic performance of the micropumps obtained by the model are in good agreement with the experimental data. The model can predict well the damping behavior of the pump.
Design of T-Shaped Micropump Based on Induced Charge Electroosmotic
Bingying Sheng; Xiaojing Mi; Kai Zhang
2013-01-01
The fluid-driven efficiency of the micropump based on induced charge electroosmotic was studied by numerical simulation method. In this paper, we propose to make some improvement against the T-shaped piping design of micropump, and we embed a janus cylinder in the junction of the T-shaped pipe for the micropump design. We offer different voltage to the inlet of the pipe and carry out the numerical study of the fluid field induced by the cylinder, and the comparison of the velocity and flux of...
A dynamic model for studying valveless electromagnetic micropumps
In this paper, a fluid–diaphragm coupling model is proposed for studying the dynamic performance of a valveless micropump. In the model, fluid inertia is included and fluid pressure is obtained by solving the coupling equation simultaneously with Navier–Stokes equations through a transient dynamic mesh simulation. This process avoids the omission of the phase shift between the pressure force on the diaphragm and the flow rate of the pump. Furthermore, in this model, empirical parameters are almost eliminated. The model was applied to study the dynamic performance of a valveless electromagnetic micropump which uses a new working principle. The obtained results show that the flow rate attains its maximum value for a range of driving frequency. For instance, the flow rate reaches 1.6 ml min−1 for frequencies of 26–30 Hz when the electromagnetic force is 20 mN. The simulation results demonstrate that the flow rate of the proposed pump is much larger than that of the diffuser pump counterpart. A MEMS prototype has been fabricated and the attained backpressure validates the new pumping principle of the pump.
A dynamic model for studying valveless electromagnetic micropumps
Dinh, T. X.; Le, N. T. M.; Dau, V. T.; Ogami, Y.
2011-02-01
In this paper, a fluid-diaphragm coupling model is proposed for studying the dynamic performance of a valveless micropump. In the model, fluid inertia is included and fluid pressure is obtained by solving the coupling equation simultaneously with Navier-Stokes equations through a transient dynamic mesh simulation. This process avoids the omission of the phase shift between the pressure force on the diaphragm and the flow rate of the pump. Furthermore, in this model, empirical parameters are almost eliminated. The model was applied to study the dynamic performance of a valveless electromagnetic micropump which uses a new working principle. The obtained results show that the flow rate attains its maximum value for a range of driving frequency. For instance, the flow rate reaches 1.6 ml min-1 for frequencies of 26-30 Hz when the electromagnetic force is 20 mN. The simulation results demonstrate that the flow rate of the proposed pump is much larger than that of the diffuser pump counterpart. A MEMS prototype has been fabricated and the attained backpressure validates the new pumping principle of the pump.
Dual independent displacement-amplified micropumps with a single actuator
Tracey, M. C.; Johnston, I. D.; Davis, J. B.; Tan, C. K. L.
2006-08-01
We report a dual-micropump structure operated by a single actuator element. The constituent micropumps are a form of micro throttle pump (MTP) comprising a narrow flow channel incorporating two microthrottles. We term this a 'linear MTP' (LMTP). The LMTP's narrowness, in conjunction with an elastomeric substrate, allows multiple, independent, LMTPs to be actuated by a single piezoelectric actuator thereby suiting it to parallel microfluidic architectures. Furthermore, LMTP elements can be combined into parallel or series composites yielding increased maximum pumping rates or back pressures, respectively, when compared to a single LMTP element. The LMTP's flow-channel-like, linear pump chamber minimizes the development of recirculatory flows associated with circular pump chambers which, in part, determine their frequency response and hence maximum pumping rates. We have modelled, fabricated and evaluated a dual-LMTP. We report operation in three modes: as two distinct pumps, as a series composite pump, and as a parallel composite pump. Operating at about 1.6 kHz, with both pumps under identical load conditions, each pump yielded maximum pumping rates of about 750 µl min-1 and back pressures of 18 kPa, both with close matching. Configured as a series composite, a 35 kPa back pressure was achieved, and configured as a parallel composite, a maximum pumping rate of 1.4 ml min-1 resulted. Images of 5 µm polystyrene beads flowing within an LMTP confirm minimal recirculatory behaviour consistent with the LMTP's increased operating frequencies compared to circular pump chamber MTPs.
Flow behavior of liquid-solid coupled system of piezoelectric micropump
Lijun LU; Jiankang WU
2008-01-01
This paper employs a shallow water model and the finite element method to approximate periodical flows of a micropump to a two-dimensional thickness-averaged flow. A liquid-solid coupled system equation of the micropump is presented. Through the mode analysis of the liquid-solid coupled system, the first-order natural frequency, diaphragm vibration shape and amplitude-frequency relationship are obtained. The vibration response of the diaphragm is calculated when an external electric field is applied. Based on the thickness-averaged flow equation, the periodical flow of the micropump is studied using the finite volume method to investigate the flow behavior and flow rate-frequency characteristics. Numerical results indicate that an optimal working frequency can be obtained, at which the flow rate of the micropump achieves the maximum when the external electric voltage is fixed.
Zhang, Tao; Wang, Qing-Ming
A fuel cell is a device that can convert chemical energy into electricity directly. Among various types of fuel cells, both polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) can work at low temperature (mini pumps, the size of the piezoelectric micropump is much smaller and the energy consumption is much lower. Thus, it is very viable and effective to use a piezoelectric valveless micropump for fuel delivery in miniaturized DMFC power systems.
Two way fluid structure interaction analysis of a valveless micropump by CFD
Cǎlimǎnescu, Ioan; Dumitrache, Constantin L.; Grigorescu, Lucian
2015-02-01
In the microfluid control system, a valve-less micropump is a necessary component. It has the ability to pump a wide variety of fluids automatically and accurately on a micro scale. The dynamic characteristics of a valve-less micropump influence the performance of the microfluid control system. Consequently, it is of great importance to be able to accurately predict the dynamic characteristics of micropumps for appropriate design and usage of the microfluid control system. In this paper, we describe a corrugated diaphragm valveless micropump approached from the Computational Fluid Dynamics point of view in which the Fluid Structure Interaction is based on the Two Way principle, meaning that the diaphragm is moving and the fluid (water like fluid) is sucked from the inlet and pushed back to the outlet using the nozzle effect. The technical solution of micropumps without valves is a very clever idea to replace the custom valves with nozzles, with the same effect but virtually without any components beside the inlet and the outlet nozzles. The paperwork is demonstrating via a complex simulation involving the structural-fluid interaction the nozzle effects and the functioning of this kind of micropumps.
Modeling and design of light powered biomimicry micropump utilizing transporter proteins
Liu, Jin; Sze, Tsun-Kay Jackie; Dutta, Prashanta
2014-11-01
The creation of compact micropumps to provide steady flow has been an on-going challenge in the field of microfluidics. We present a mathematical model for a micropump utilizing Bacteriorhodopsin and sugar transporter proteins. This micropump utilizes transporter proteins as method to drive fluid flow by converting light energy into chemical potential. The fluid flow through a microchannel is simulated using the Nernst-Planck, Navier-Stokes, and continuity equations. Numerical results show that the micropump is capable of generating usable pressure. Designing parameters influencing the performance of the micropump are investigated including membrane fraction, lipid proton permeability, illumination, and channel height. The results show that there is a substantial membrane fraction region at which fluid flow is maximized. The use of lipids with low membrane proton permeability allows illumination to be used as a method to turn the pump on and off. This capability allows the micropump to be activated and shut off remotely without bulky support equipment. This modeling work provides new insights on mechanisms potentially useful for fluidic pumping in self-sustained bio-mimic microfluidic pumps. This work is supported in part by the National Science Fundation Grant CBET-1250107.
Actuation method and apparatus, micropump, and PCR enhancement method
Ullakko, Kari; Mullner, Peter; Hampikian, Greg; Smith, Aaron
2015-07-28
An actuation apparatus includes at least one magnetic shape memory (MSM) element containing a material configured to expand and/or contract in response to exposure to a magnetic field. Among other things, the MSM element may be configured to pump fluid through a micropump by expanding and/or contracting in response to the magnetic field. The magnetic field may rotate about an axis of rotation and exhibit a distribution having a component substantially perpendicular to the axis of rotation. Further, the magnetic field distribution may include at least two components substantially orthogonal to one another lying in one or more planes perpendicular to the axis of rotation. The at least one MSM element may contain nickel, manganese, and gallium. A polymerase chain reaction (PCR) may be enhanced by contacting a PCR reagent and DNA material with the MSM element.
Backward flow in a surface tension driven micropump
A surface tension driven micropump harnessing the pressure difference generated by drops of different curvature radii proves to be a simple and attractive passive method to drive fluid flow in microdevices. Here we observed the appearance of backward flow when the initial sizes of the droplets at the inlet and outlet ports are similar. To explain this phenomenon several hypotheses have been investigated. Consideration of the inertia of the fluid in the channel revealed that it alone is insufficient to explain the observed backward flow. We discovered that rotational flow inside the outlet droplet could be a source of inertia, explaining the generation of the backward flow. In addition, we have experimentally determined that the ratio of the volumes of the initial outlet drop and inlet drop correlates with the occurrence of the backward flow. (note)
In vivo organ specific drug delivery with implantable peristaltic pumps.
Speed, Joshua S; Hyndman, Kelly A
2016-01-01
Classic methods for delivery of agents to specific organs are technically challenging and causes superfluous stress. The current study describes a method using programmable, implantable peristaltic pumps to chronically deliver drugs in vivo, while allowing animals to remain undisturbed for accurate physiological measurements. In this study, two protocols were used to demonstrate accurate drug delivery to the renal medulla. First, the vasopressin receptor-2 agonist, dDAVP, was delivered to the renal medulla resulting in a significant increase in water retention, urine osmolality and aquaporin-2 expression and phosphorylation. Second, in a separate group of rats, the histone deacetylase (HDAC) inhibitor, MS275, was delivered to the renal medulla. HDAC inhibition resulted in a significant increase in histone H3-acetylation, the hallmark for histone deacetylase inhibition. However, this was confined to the medulla, as the histone H3-acetylation was similar in the cortex of vehicle and MS275 infused rats, suggesting targeted drug delivery without systemic spillover. Thus, implantable, peristaltic pumps provide a number of benefits compared to externalized chronic catheters and confer specific delivery to target organs. PMID:27185292
Design, fabrication, and characterization of a valveless magnetic travelling-wave micropump
In this paper, we propose a valveless magnetic micropump for lab-on-a-chip and microfluidic applications. The micropump, based on polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA), consists primarily of a saw-toothed microchannel, two substrates, and two integrated NdFeB permanent magnetic arrays. The travelling wave beneath the top wall of the elastic microchannel can be induced by the proper magnetic pole orientation arrangement of these magnetic arrays, and the liquid particles are then transported along with the travelling wave in the microchannel. Appropriate geometry of the saw-toothed microchannel was also studied for optimizing the performance of the micropump. Experimental characterization of the micropump has been performed in terms of the frequency response of the flow rate and backpressure. The results demonstrate that this micropump is capable of reliably generating a maximum flow rate of 342.4 μL min−1 and operating against a high backpressure of 1.67 kPa. (paper)
An Electromagnetically-Actuated All-PDMS Valveless Micropump for Drug Delivery
Farid Amirouche
2011-07-01
Full Text Available This paper presents the fabrication process of a single-chamber planar valveless micropump driven by an external electromagnetic actuator. This micropump features a pair of micro diffuser and nozzle elements used to rectify the fluid flow, and an elastic magnetic membrane used to regulate the pressure in the enclosed fluid chamber. Polydimethylsiloxane (PDMS is used as the main construction material of this proposed micropump, including the structural substrate and the planar actuation membrane embedded with a thin micro magnet. Both the Finite Element Method and experimental analysis are used to assess the PDMS-membrane actuation under the applied electromagnetic forces and characterize the pump performance at variable working conditions. The resonant frequency of this micropump is identified experimentally and de-ionized (DI water is loaded to account for the coupling effects of the working fluid. The experimental data was used to demonstrate the reliability of flow rates and how it can be controlled by consistently adjusting the driving frequencies and currents. The proposed micropump is capable of delivering a maximum flow rate of 319.6 μL/min and a maximum hydrostatic backpressure of 950 Pa (9.5 cm H2O. The planar design feature of the pump allows for potential integration of the pump with other PDMS-based microfluidic systems for biomedical applications.
Design, fabrication, and characterization of a valveless magnetic travelling-wave micropump
Yu, Huawei; Ye, Weixiang; Zhang, Wei; Yue, Zhao; Liu, Guohua
2015-06-01
In this paper, we propose a valveless magnetic micropump for lab-on-a-chip and microfluidic applications. The micropump, based on polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA), consists primarily of a saw-toothed microchannel, two substrates, and two integrated NdFeB permanent magnetic arrays. The travelling wave beneath the top wall of the elastic microchannel can be induced by the proper magnetic pole orientation arrangement of these magnetic arrays, and the liquid particles are then transported along with the travelling wave in the microchannel. Appropriate geometry of the saw-toothed microchannel was also studied for optimizing the performance of the micropump. Experimental characterization of the micropump has been performed in terms of the frequency response of the flow rate and backpressure. The results demonstrate that this micropump is capable of reliably generating a maximum flow rate of 342.4 μL min-1 and operating against a high backpressure of 1.67 kPa.
Peristaltic Transport of a Couple Stress Fluid : Some Physiological Applications
Maiti, S
2010-01-01
The present paper deals with a theoretical investigation of the peristaltic transport of a couple stress fluid in a porous channel. The study is motivated towards the physiological flow of blood in the micro-circulatory system, by taking account of the particle size effect. The velocity, pressure gradient, stream function and frictional force of blood are investigated, when the Reynolds number is small and the wavelength is large, by using appropriate analytical and numerical methods. Effects of different physical parameters reflecting porosity, Darcy number, couple stress parameter as well as amplitude ratio on velocity profiles, pumping action and frictional force, streamlines pattern and trapping of blood are studied with particular emphasis. The computational results are presented in graphical form. The results are found to be in good agreement with those of Shapiro et. al \\cite{r25} that was carried out for a non-porous channel in the absence of couple stress effect. The present study puts forward an imp...
Fabrication and study of AC electro-osmotic micropumps
Guo, Xin
In this thesis, microelectrode arrays of micropumps have been designed, fabricated and characterized for transporting microfluid by AC electro-osmosis (ACEO). In particular, the 3D stepped electrode design which shows superior performance to others in literature is adopted for making micropumps, and the performance of such devices has been studied and explored. A novel fabrication process has also been developed in the work, realizing 3D stepped electrodes on a flexible substrate, which is suitable for biomedical use, for example glaucoma implant. There are three major contributions to ACEO pumping in the work. First, a novel design of 3D "T-shaped" discrete electrode arrays was made using PolyMUMPsRTM process. The breakthrough of this work was discretizing the continuous 3D stepped electrodes which were commonly seen in the past research. The "T-shaped" electrodes did not only create ACEO flows on the top surfaces of electrodes but also along the side walls between separated electrodes. Secondly, four 3D stepped electrode arrays were designed, fabricated and tested. It was found from the experiment that PolyMUMPsRTM ACEO electrodes usually required a higher driving voltage than gold electrodes for operation. It was also noticed that a simulation based on the modified model taking into account the surface oxide of electrodes showed a better agreement with the experimental results. It thus demonstrated the possibility that the surface oxide of electrodes had impact on fluidic pumping. This methodology could also be applied to metal electrodes with a native oxide layer such as titanium and aluminum. Thirdly, a prototype of the ACEO pump with 3D stepped electrode arrays was first time realized on a flexible substrate using Kapton polyimide sheets and packaged with PDMS encapsulants. Comprehensive experimental testing was also conducted to evaluate the mechanical properties as well as the pumping performance. The experimental findings indicated that this fabrication
Static characteristic analysis on a hydrodynamic bearing of a hydraulic suspended micropump
A hydraulic suspended micropump was designed based on the conception of double suction impeller. To study the running performance of the micropump, three dimensional simulation of the static characteristic of the hydrodynamic bearing at rated condition was performed. Parameters such as the eccentricity and rotational speed, having effect on the bearing capacity, were analyzed. Results show that the eccentricity and rotational speed have a certain effect on the bearing capacity. The region of the maximum static pressure and the positive pressure changes as the eccentricity increases. The bearing capacity improves as the rotational speed increases. All the results can provide a academic basis for the improvement and application of a hydrodynamic bearing of a micropump
Development of Stepper motor based Two DOF Robotic Arm Transferring Liquid using Peristaltic Pump
Padma Thiagarajan; Sudha Ramasamy; Karthikesh.R; Manikandan.P
2013-01-01
The aim of this work is to transfer liquid contents from one micro cell to another using two stepper motors and a peristaltic pump. There are two objectives here. One is to develop a low cost roboticarm using stepper motors. The second objective is the control and calibration of the peristaltic pump. All parts are controlled and operated by their respective microcontrollers. Fulfillment of both the objectives leads to an integrated system to transfer liquids from one cell to another. The end ...
Peristaltic Flow of Phan-Thien-Tanner Fluid in an Asymmetric Channel with Porous Medium
Kuppalapalle Vajravelu; S.Sreenadh; Lakshminarayana, P; G. Sucharitha; Rashidi, M. M.
2016-01-01
This paper deals with peristaltic transport of Phan-Thien-Tanner fluid in an asymmetric channel induced by sinusoidal peristaltic waves traveling down the flexible walls of the channel. The flow is investigated in a wave frame of reference moving with the velocity of the waveby using the long wavelength and low Reynolds number approximations.The nonlinear governing equations are solved employing a perturbation method by choosing as the perturbation parameter. The expressions for velocity, s...
This paper reports a new membrane-based pneumatic micropump with new serpentine-shape (S-shape) pneumatic channels intended for achieving high-throughput pumping in a microfluidic system at a relatively low pumping rate and a board flow rate range. The key feature of this design is the ability to modulate the pumping rates by fine-tuning the fluidic resistance of injected compressed air in the designed pneumatic microchannels and the chambers of the micropump. In the study, several S-shape pneumatic micropumps with various layouts were designed and fabricated based on thick-film photoresist lithography and polydimethylsiloxane (PDMS) replication processes. To investigate designs with a suitable pumping performance, S-shape pneumatic micropumps with varied lengths (1000, 5000 and 10 000 µm), varied widths (20, 40 and 200 µm) of the pneumatic microchannel bridging two rectangular pneumatic chambers, and different numbers of pneumatic channel bends (two and four U-shape bends) were designed and evaluated experimentally by using high-speed CCD-coupled microscopic observation of the movement of PDMS membrane pulsation and pumping rate measurements. The results revealed that under the experimental conditions studied, the layout of the S-shape pneumatic micropump with three rectangular pneumatic chambers, 5000 µm long and 40 µm wide pneumatic microchannel and four U-shape bends in the pneumatic microchannel was found to be capable of providing a broader pumping rate range from 0 to 539 µl h−1 compared to the other designs. As a whole, the experimental results demonstrate the use of fluidic resistance of injected air in a pneumatic micropump with S-shape layout to control its pumping performance, which largely expands the flexibility of its pumping application in a microfluidic system
Simulations of Micropumps Based on Tilted Flexible Fibers
Hancock, Matthew; Elabbasi, Nagi; Demirel, Melik
2015-11-01
Pumping liquids at low Reynolds numbers is challenging because of the principle of reversibility. We report here a class of microfluidic pump designs based on tilted flexible structures that combines the concepts of cilia (flexible elastic elements) and rectifiers (e.g., Tesla valves, check valves). We demonstrate proof-of-concept with 2D and 3D fluid-structure interaction (FSI) simulations in COMSOL Multiphysics®of micropumps consisting of a source for oscillatory fluidic motion, e.g. a piston, and a channel lined with tilted flexible rods or sheets to provide rectification. When flow is against the rod tilt direction, the rods bend backward, narrowing the channel and increasing flow resistance; when flow is in the direction of rod tilt, the rods bend forward, widening the channel and decreasing flow resistance. The 2D and 3D simulations involve moving meshes whose quality is maintained by prescribing the mesh displacement on guide surfaces positioned on either side of each flexible structure. The prescribed displacement depends on structure bending and maintains mesh quality even for large deformations. Simulations demonstrate effective pumping even at Reynolds numbers as low as 0.001. Because rod rigidity may be specified independently of Reynolds number, in principle, rod rigidity may be reduced to enable pumping at arbitrarily low Reynolds numbers.
Design, modeling and fabrication of a constant flow pneumatic micropump
Inman, Walker; Domansky, Karel; Serdy, James; Owens, Bryan; Trumper, David; Griffith, Linda G.
2007-05-01
This paper characterizes a bi-directional pneumatic diaphragm micropump and presents a model for performance of an integrated fluidic capacitor. The fluidic capacitor is used to convert pulsatile flow into a nearly continuous flow stream. The pump was fabricated in acrylic using a CNC mill. The stroke volume of the pump is ~1 µL. The pump is self-priming, bubble tolerant and insensitive to changes in head pressure and pneumatic pressure within its operating range. The pump achieves a maximum flow rate of 5 mL min-1 against zero head pressure. With pneumatic pressure set to 40 kPa, the pump can provide flow at 2.6 mL min-1 against a head pressure of 25 kPa. A nonlinear model for the capacitor was developed and compared with experimental results. The ratio of the time constant of the capacitor to the cycle time of the pump is shown to be an accurate indicator of capacitor performance and a useful design tool.
157 cases of gastrointestinal cancer patients after resection were randomly divided into treated group and control group. The treated group (intraperitoneal hyperthermic perfusion chemotherapy combined with postoperative continuous intraarterial infusion and intravenous micro-pump chemotherapy) consisted of 72 cases, the control group (Intravenous chemotherapy), 85 cases. The peritoneal and hepatic metastasis rates and 3 a survival rate were studied. The intraperitoneal hyperthermic perfusion chemotherapy combined with the postoperative continuous intraarterial infusion and intravenous micro-pump chemotherapy is an effective way to control the recurrence on the peritoneal and hepatic metastasis of advanced gastrointestinal neoplasms after operation. (authors)
Lee, Sangki; Kim, Kwang J.
2006-08-01
This paper presents the design and flow rate predictions of an IPMC (ionic polymer-metal composite) actuator-driven valve-less micropump. It should be noted that IPMC is a promising material candidate for micropump applications since it can be operated with low input voltages and can produce large stroke volumes, while having controllable flow rates. The micropump manufacturing process with IPMC is also convenient; it is anticipated that the manufacturing cost of the IPMC micropump is competitive with other technologies. In order to design an effective IPMC diaphragm that functions as an actuating motor for a micropump, a finite element analysis (FEA) was utilized to optimize the electrode shape of the IPMC diaphragm and estimate its stroke volumes. In addition, the effect of the pump chamber pressure on the stroke volume was numerically investigated. Appropriate inlet and outlet nozzle/diffuser elements were also studied for the valve-less micropump. Based on the selected geometry of nozzle/diffuser elements and the estimated stroke volume of the IPMC diaphragm, the flow rate of the micropump was estimated at a low Reynolds number of about 50.
A self-priming, high performance, check valve diaphragm micropump made from SOI wafers
Kang, Jianke; Mantese, Joseph V.; Auner, Gregory W.
2008-12-01
In this paper, we describe a self-priming high performance piezoelectrically actuated check valve diaphragm micropump. The micropump was fabricated from three wafers: two silicon-on-insulator (SOI) wafers and one silicon wafer. A process named 'SOI/SOI wafer bonding and etching back followed by a second wafer bonding' was developed in order to make the core components of this device which included an inlet check valve, an outlet check valve, a diaphragm and a chamber. The movable structures of this device, i.e. the check valves and the diaphragm, were fabricated from the device layers of the two bonded SOI wafers. Taking advantages of SOI wafer technology and etch-stop layers, the vertical parameters of the movable structures were precisely controlled in fabrication. The micropump was self-priming without any pre-filling process. The pumping rate of the micropump was linearly adjustable from 0 to 650l µm min-1 by adjusting frequency. The maximum pumping rate was 860 µl min-1 and the maximum pumping pressure was approximately 10.5 psi. The power consumption of the device was less than 1.2 mW.
A self-priming, high performance, check valve diaphragm micropump made from SOI wafers
In this paper, we describe a self-priming high performance piezoelectrically actuated check valve diaphragm micropump. The micropump was fabricated from three wafers: two silicon-on-insulator (SOI) wafers and one silicon wafer. A process named 'SOI/SOI wafer bonding and etching back followed by a second wafer bonding' was developed in order to make the core components of this device which included an inlet check valve, an outlet check valve, a diaphragm and a chamber. The movable structures of this device, i.e. the check valves and the diaphragm, were fabricated from the device layers of the two bonded SOI wafers. Taking advantages of SOI wafer technology and etch-stop layers, the vertical parameters of the movable structures were precisely controlled in fabrication. The micropump was self-priming without any pre-filling process. The pumping rate of the micropump was linearly adjustable from 0 to 650l µm min−1 by adjusting frequency. The maximum pumping rate was 860 µl min−1 and the maximum pumping pressure was approximately 10.5 psi. The power consumption of the device was less than 1.2 mW
Characteristic of TiNi(Cu) shape memory thin film based on micropump
Zhang, Huijun; Qiu, Chengjun
2009-07-01
Shape memory thin films offer a unique combination of novel properties and have the potential to become a primary actuating mechanism for micropumps. In this study, a micropump driven by TiNiCu shape memory thin film is designed and fabricated. The micropump is composed of a TiNiCu/Si bimorph driving membrane, a pump chamber and two inlet and outlet check valves. The property of TiNiCu films and driving capacity of TiNiCu/Si bimorph driving membrane are investigated. By using the recoverable force of TiNiCu thin film and biasing force of silicon membrane, the actuation diaphragm realizes reciprocating motion effectively. Experimental results show that the film surface appears a smooth and featureless morphology without any cracks, and the hysteresis width ΔT of TiNiCu film is about 2-3°C, the micropump driving by TiNiCu film has good performance, such as high pumping yield, high working frequency, stable driving capacity, and long fatigue life time.
Metal additive manufacturing of a high-pressure micro-pump
Wits, Wessel W.; Weitkamp, Sander J.; Es, van J.
2013-01-01
For the thermal control of future space applications pumped two-phase loops are an essential part to handle the increasing thermal power densities. This study investigates the design of a reliable, leak tight, low-weight and high-pressure micro-pump for small satellite applications. The developed mi
Peristaltic motion of third grade fluid in curved channel
S.HINA; M.MUSTAFA; T.HAYAT; F.E.ALSAADI
2014-01-01
Analysis is performed to study the slip effects on the peristaltic flow of non-Newtonian fluid in a curved channel with wall properties. The resulting nonlinear partial differential equations are transformed to a single ordinary differential equation in a stream function by using the assumptions of long wavelength and low Reynolds number. This differential equation is solved numerically by employing the built-in routine for solving nonlinear boundary value problems (BVPs) through the software Mathematica. In addition, the analytic solutions for small Deborah number are computed with a regular perturbation technique. It is noticed that the symmetry of bolus is destroyed in a curved channel. An intensification in the slip effect results in a larger magnitude of axial velocity. Further, the size and circulation of the trapped boluses increase with an increase in the slip parameter. Different from the case of planar channel, the axial velocity profiles are tilted towards the lower part of the channel. A comparative study between analytic and numerical solutions shows excellent agreement.
Peristaltic Pumping of Blood in micro-vessels of Non-uniform Cross-section
Misra, J C
2010-01-01
The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered of non-uniform cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. The Reynolds number is considered to be small. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. Basing upon the study, extensive numerical calculations has been made. The study reveals that peristaltic pumping as well as velocity and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude of the amplitude ratio and the value of the fluid index.
Peristaltic transport of Carreau-Yasuda fluid in a curved channel with slip effects.
Tasawar Hayat
Full Text Available The wide occurrence of peristaltic pumping should not be surprising at all since it results physiologically from neuro-muscular properties of any tubular smooth muscle. Of special concern here is to predict the rheological effects on the peristaltic motion in a curved channel. Attention is focused to develop and simulate a nonlinear mathematical model for Carreau-Yasuda fluid. The progressive wave front of peristaltic flow is taken sinusoidal (expansion/contraction type. The governing problem is challenge since it has nonlinear differential equation and nonlinear boundary conditions even in the long wavelength and low Reynolds number regime. Numerical solutions for various flow quantities of interest are presented. Comparison for different flow situations is also made. Results of physical quantities are interpreted with particular emphasis to rheological characteristics.
Munawwar Ali Abbas
2016-03-01
Full Text Available Entropy generation during peristaltic flow of nanofluids in a non-uniform two dimensional channel with compliant walls has been studied. The mathematical modelling of the governing flow problem is obtained under the approximation of long wavelength and zero Reynolds number (creeping flow regime. The resulting non-linear partial differential equations are solved with the help of a perturbation method. The analytic and numerical results of different parameters are demonstrated mathematically and graphically. The present analysis provides a theoretical model to estimate the characteristics of several Newtonian and non-Newtonian fluid flows, such as peristaltic transport of blood.
Flow Rate Driven by Peristaltic Movement in Plasmodial Tube of Physarum Polycephalum
Yamada, Hiroyasu; Nakagaki, Toshiyuki
2008-07-01
We report a theoretical analysis of protoplasmic streaming driven by peristaltic movement in an elastic tube of an amoeba-like organism. The Plasmodium of Physarum polycephalum, a true slime mold, is a large amoeboid organism that adopts a sheet-like form with a tubular network. The network extends throughout the Plasmodium and enables the transport and circulation of chemical signals and nutrients. This tubular flow is driven by periodically propagating waves of active contraction of the tube cortex, a process known as peristaltic movement. We derive the relationship between the phase velocity of the contraction wave and the flow rate, and we discuss the physiological implications of this relationship.
Analysis on and Optimization of a Circular Piezoelectric Composite Laminate for a Micro-Pump Driver
Among the various micro-pump actuation devices, piezoelectric composite laminate actuation has become an effective method. Due to lacking of analysis treatments, the design of this type micro-pump is in a great limitation. In this paper, an electromechanical-coupled mechanics model is established for the circle-flake micro-actuator. A kind of analysis and design method is presented that piezoelectric plate's radial strain induced by inverse piezoelectric effect is equivalently substituted with transverse stress on piezoelectric composite laminates. It is pointed out that the equivalent transverse load depends on the edge electric field distribution of parallel plate capacitor. The question has been solved that where the neutral plane in the piezoelectric composite laminates lies. Finally, an optimization design is developed on the radius ratio of piezoelectric-to-silicon plate radius by utilizing of FEA modeling
Zhao, Guangpu [School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021 (China); Jian, Yongjun, E-mail: jianyj@imu.edu.cn [School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021 (China); Chang, Long [School of Mathematics and Statistics, Inner Mongolia University of Finance and Economics, Hohhot, Inner Mongolia 010051 (China); Buren, Mandula [School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021 (China)
2015-08-01
By using the method of separation of variables, an analytical solution for the magnetohydrodynamic (MHD) flow of the generalized Maxwell fluids under AC electric field through a two-dimensional rectangular micropump is reduced. By the numerical computation, the variations of velocity profiles with the electrical oscillating Reynolds number Re, the Hartmann number Ha, the dimensionless relaxation time De are studied graphically. Further, the comparison with available experimental data and relevant researches is presented. - Highlights: • MHD flow of the generalized Maxwell fluids under AC electric field is analyzed. • The MHD flow is confined to a two-dimensional rectangular micropump. • Analytical solution is obtained by using the method of separation of variables. • The influences of related parameters on the MHD velocity are discussed.
By using the method of separation of variables, an analytical solution for the magnetohydrodynamic (MHD) flow of the generalized Maxwell fluids under AC electric field through a two-dimensional rectangular micropump is reduced. By the numerical computation, the variations of velocity profiles with the electrical oscillating Reynolds number Re, the Hartmann number Ha, the dimensionless relaxation time De are studied graphically. Further, the comparison with available experimental data and relevant researches is presented. - Highlights: • MHD flow of the generalized Maxwell fluids under AC electric field is analyzed. • The MHD flow is confined to a two-dimensional rectangular micropump. • Analytical solution is obtained by using the method of separation of variables. • The influences of related parameters on the MHD velocity are discussed
A novel micropump with fixed-geometry valves and low leakage flow
Hwang, Il-Han; An, Jae-Yong; Ko, Kwang-Hee; Shin, Sang-Mo; Lee, Jong-Hyun
2007-08-01
A novel micropump with fixed-geometry valves was designed and tested with a leakage barrier to reduce leakage flow. Conventional micropumps with fixed-geometry valves have achieved net positive fluid flow from different fluid resistances in diffuser/nozzle channels. However, those micropumps are susceptible to leakage flow even at low pressure differences between the inlet and the outlet because the channels remain normally open state when the pumps are not in operation. Therefore, a leakage barrier in the chamber was designed to reduce leakage flow without interfering with the net positive fluid flow of the diffuser/nozzle channels. The diffuser/nozzle channels, the chamber and the leakage barrier were fabricated on the silicon substrate by KOH etching and the silicon substrate was anodically bonded with a Pyrex glass plate. A PZT disk was bonded on the glass plate by epoxy and was actuated to oscillate the glass diaphragm for flow generation. When the micropump is not operating, the leakage barrier removes most of the gap between the glass plate and the bottom of the chamber. It was experimentally confirmed that the leakage barrier reduced the leakage flow by 96% compared to the case of no leakage barrier at a pressure difference of -400 Pa. Moreover, by applying the holding dc voltage to the PZT disk, a smaller gap can be obtained reducing the leakage flow further down to 0.043 µL min-1 at a holding dc voltage of 100 V. The maximum flow rate was 3.9 µL min-1 at a peak-to-peak driving voltage of 150 V at 20 Hz with a maximum back pressure of around 800 Pa. The approximate device size was 18 × 25 mm2.
A novel fabrication process to release a valveless micropump on a flexible substrate
Wei, Yang; Torah, R.N.; Yang, Kai; Beeby, S. P.; Tudor, John
2013-01-01
This paper reports, for the first time, the design, fabrication and testing of a valveless micropump, entirely screen printed onto a flexible polyimide (Kapton) substrate by using sacrificial, polymer-structural and piezoelectric layers. The sacrificial layer, used to achieve a pump chamber and inlet/outlet channels, is thermally removed, analogous to a standard MEMS sacrificial process. Applying a sinusoidal AC voltage to the piezoelectric layer drives a flexible membrane which pumps liquid...
The self-generated peristaltic motion of cascaded pneumatic actuators for micro pumps
This paper presents a new actuation mechanism for the self-generated peristaltic motion of cascaded actuators and its application to micro pumps. The operational method is based on the fluidic circuit of an elastic tube. The elastic tube is modeled as a ladder network consisting of fluidic resistances in series and fluidic capacitances in parallel like multi-stage low-pass filters in an electrical circuit. All segments of the lumped model of the elastic tube have different dynamic characteristics because their time constants are different. In other words, all segments should be deformed sequentially like peristaltic motion. This phenomenon has good potential to cause peristaltic motion of the cascaded actuators in response to the application of single-phase pneumatic signals. Analogues between the electrical and fluidic circuits were applied to a pneumatic micro pump with a micro fluidic channel and three pneumatic actuators connecting a unique micro channel for supplying the compressed air. The polymeric micro pumps were fabricated with soft lithography using only polyimethylsiloxsane. The proposed working principle was verified through simulation of the static deformation of the cascaded actuator diaphragms and the actuator, as well as tested experimentally. The dual operational modes of the proposed device (i.e., rubber-seal valve and peristaltic pumping mode) were also verified and successfully demonstrated in a liquid pumping test of the single and double pumps
Development of Stepper motor based Two DOF Robotic Arm Transferring Liquid using Peristaltic Pump
Padma Thiagarajan
2013-02-01
Full Text Available The aim of this work is to transfer liquid contents from one micro cell to another using two stepper motors and a peristaltic pump. There are two objectives here. One is to develop a low cost roboticarm using stepper motors. The second objective is the control and calibration of the peristaltic pump. All parts are controlled and operated by their respective microcontrollers. Fulfillment of both the objectives leads to an integrated system to transfer liquids from one cell to another. The end effecter of the robotic arm is connected to the peristaltic pump. The pump has two pipes connected to it. Through one pipe it takes in the liquid and through the other pipe it delivers the liquid into the second cell. After transferring one sample of liquid, the arm moves to a cleaning module where the end effecter is cleaned to avoid cross contamination. The robotic arm is built using stepper motors and controlled using Atmega32 microcontroller whereas the peristaltic pump is controlled and calibrated using 8051 microcontroller. The pumping is done with the help of DC motors. As a result, the working of the robotic arm and theperistaltic pump is verified experimentally.
The self-generated peristaltic motion of cascaded pneumatic actuators for micro pumps
Jeong, Ok Chan; Konishi, Satoshi
2008-08-01
This paper presents a new actuation mechanism for the self-generated peristaltic motion of cascaded actuators and its application to micro pumps. The operational method is based on the fluidic circuit of an elastic tube. The elastic tube is modeled as a ladder network consisting of fluidic resistances in series and fluidic capacitances in parallel like multi-stage low-pass filters in an electrical circuit. All segments of the lumped model of the elastic tube have different dynamic characteristics because their time constants are different. In other words, all segments should be deformed sequentially like peristaltic motion. This phenomenon has good potential to cause peristaltic motion of the cascaded actuators in response to the application of single-phase pneumatic signals. Analogues between the electrical and fluidic circuits were applied to a pneumatic micro pump with a micro fluidic channel and three pneumatic actuators connecting a unique micro channel for supplying the compressed air. The polymeric micro pumps were fabricated with soft lithography using only polyimethylsiloxsane. The proposed working principle was verified through simulation of the static deformation of the cascaded actuator diaphragms and the actuator, as well as tested experimentally. The dual operational modes of the proposed device (i.e., rubber-seal valve and peristaltic pumping mode) were also verified and successfully demonstrated in a liquid pumping test of the single and double pumps.
A mathematical model for the peristaltic flow of chyme movement in small intestine.
Tripathi, Dharmendra
2011-10-01
A mathematical model based on viscoelastic fluid (fractional Oldroyd-B model) flow is considered for the peristaltic flow of chyme in small intestine, which is assumed to be in the form of an inclined cylindrical tube. The peristaltic flow of chyme is modeled more realistically by assuming that the peristaltic rush wave is a sinusoidal wave, which propagates along the tube. The governing equations are simplified by making the assumptions of long wavelength and low Reynolds number. Analytical approximate solutions of problem are obtained by using homotopy analysis method and convergence of the obtained series solution is properly checked. For the realistic values of the emerging parameters such as fractional parameters, relaxation time, retardation time, Reynolds number, Froude number and inclination of tube, the numerical results for the pressure difference and the frictional force across one wavelength are computed and discussed the roles played by these parameters during the peristaltic flow. On the basis of this study, it is found that the first fractional parameter, relaxation time and Froude number resist the movement of chyme, while, the second fractional parameter, retardation time, Reynolds number and inclination of tube favour the movement of chyme through the small intestine during pumping. It is further revealed that size of trapped bolus reduces with increasing the amplitude ratio whereas it is unaltered with other parameters. PMID:21802431
Peristaltic flow of a Maxwell fluid in a channel with compliant walls
Ali, Nasir [Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000 (Pakistan)], E-mail: nasirali_qau@yahoo.com; Hayat, Tasawar [Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000 (Pakistan); Asghar, Saleem [Department of Mathematical Sciences, COMSATS Institute of Information Technology, Islamabad (Pakistan)
2009-01-15
This paper describes the peristaltic motion of a non-Newtonian fluid in a channel having compliant boundaries. Constitutive equations for a Maxwell fluid have been used. Perturbation method has been used for the analytic solution. The influence of pertinent parameters is analyzed. Comparison of the present analysis of Maxwell fluid is made with the existing results of viscous fluid.
Slip and heat transfer effects on peristaltic motion of a Carreau fluid in an asymmetric channel
Hayat, Tasawar [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; King Saud Univ., Riyadh (Saudi Arabia). Dept. of Mathematics; Saleem, Najma [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; Hendi, Awatif A. [Dept. of Physics, Riyadh (Saudi Arabia). Faculty of Science
2010-12-15
An analysis has been carried out for peristaltic flow and heat transfer of a Carreau fluid in an asymmetric channel with slip effect. The governing problem is solved under long wavelength approximation. The variations of pertinent dimensionless parameters on temperature are discussed. Pumping and trapping phenomena are studied. (orig.)
Slip effects on the magnetohydrodynamic peristaltic flow of a maxwell fluid
Hayat, Tasawar [Quiad-I-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; King Saud Univ., Riyadh (Saudi Arabia). Dept. of Mathematics; Hina, Sadia [Quiad-I-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; Hendi, Awatif A. [Dept. of Physics, Riyadh (Saudi Arabia). Faculty of Science
2010-12-15
The influence of slip on the magnetohydrodynamic (MHD) peristaltic flow in a planar channel with compliant walls is examined. An incompressible Maxwell fluid saturates the porous medium. An established solution is valid for small wave number. The mathematical expression of the stream function is presented. Several interesting flow parameters are sketched and examined. (orig.)
Deformation analysis of a film-overlapped micro-pump membrane structure
A novel approach is developed to study a film-overlapped membrane structure. Meanwhile, the established model is employed to design the micro-pump membrane structure and to evaluate its pumping efficiency. Two-dimensional coupling effects between the overlapping actuator films and the deformable membrane are thoroughly investigated, including the influences on the membrane from the overlapping films' elongation effects, Poisson's ratio effects and shear strain effects. Overall deformations and interactions for the three-layer membrane structures are accurately calculated through exercising the developed model, in contrast to what difficulties are usually encountered in carrying out FEM methods with very thin elements meshed for the actuator films. Furthermore, this study demonstrates that the high stiffness of the actuating metal films needs to be reflected in the equivalent stiffness of the membrane structures, especially when the sizes of the actuator films become compatible with the sizes of the membranes. Hence, the optimal micro-pumping efficiency of a membrane structure is acquired upon exercising the developed model, and larger sizes of the actuating films do not definitely obtain larger pumping efficiencies for the electromagnetically actuated micro-pumps
So, Hongyun
2014-01-01
This paper presents a microfluidic pump operated by an asymmetrically deformed membrane, which was inspired by caterpillar locomotion. Almost all mechanical micropumps consist of two major components of fluid halting and fluid pushing parts, whereas the proposed caterpillar locomotion-inspired micropump has only a single, bilaterally symmetric membrane-like teardrop shape. A teardrop-shaped elastomeric membrane was asymmetrically deformed and then consecutively touched down to the bottom of the chamber in response to pneumatic pressure, thus achieving fluid pushing. Consecutive touchdown motions of the teardrop-shaped membrane mimicked the propagation of a caterpillar\\'s hump during its locomotory gait. The initial touchdown motion of the teardrop-shaped membrane at the centroid worked as a valve that blocked the inlet channel, and then, the consecutive touchdown motions pushed fluid in the chamber toward the tail of the chamber connected to the outlet channel. The propagation of the touchdown motion of the teardrop-shaped membrane was investigated using computational analysis as well as experimental studies. This caterpillar locomotion-inspired micropump composed of only a single membrane can provide new opportunities for simple integration of microfluidic systems. © the Partner Organisations 2014.
So, Hongyun; Pisano, Albert P; Seo, Young Ho
2014-07-01
This paper presents a microfluidic pump operated by an asymmetrically deformed membrane, which was inspired by caterpillar locomotion. Almost all mechanical micropumps consist of two major components of fluid halting and fluid pushing parts, whereas the proposed caterpillar locomotion-inspired micropump has only a single, bilaterally symmetric membrane-like teardrop shape. A teardrop-shaped elastomeric membrane was asymmetrically deformed and then consecutively touched down to the bottom of the chamber in response to pneumatic pressure, thus achieving fluid pushing. Consecutive touchdown motions of the teardrop-shaped membrane mimicked the propagation of a caterpillar's hump during its locomotory gait. The initial touchdown motion of the teardrop-shaped membrane at the centroid worked as a valve that blocked the inlet channel, and then, the consecutive touchdown motions pushed fluid in the chamber toward the tail of the chamber connected to the outlet channel. The propagation of the touchdown motion of the teardrop-shaped membrane was investigated using computational analysis as well as experimental studies. This caterpillar locomotion-inspired micropump composed of only a single membrane can provide new opportunities for simple integration of microfluidic systems. PMID:24812661
The NeuroMedicator is a micropump integrated with application-specific silicon microprobes aimed for drug delivery in neural research with small animals. The micropump has outer dimensions of 11 × 15 × 3 mm3 and contains 16 reservoirs each having a capacity of 0.25 µL. Thereby, the reservoirs are interconnected in a pearl-chain-like manner and are connected to two 8 mm long silicon microprobes. Each microprobe has a cross-sectional area of 250 × 250 µm2 and features an integrated drug delivery channel of 50 × 50 µm2 with an outlet of 25 µm in diameter. The drug is loaded to the micropump prior to implantation. After implantation, individual 0.25 µL portions of drug can be sequentially released by short heating pulses applied to a polydimethylsiloxane (PDMS) layer containing Expancel® microspheres. Due to local, irreversible thermal expansion of the elastic composite material, the drug is displaced from the reservoirs and released through the microprobe outlet directly to the neural tissue. While implanted, leakage of drug by diffusion occurs due to the open microprobe outlets. The maximum leakage within the first three days after implantation is calculated to be equivalent to 0.06 µL of drug solution. (paper)
Li, Bowei; Jiang, Lei; Xie, Hua; Gao, Yan; Qin, Jianhua; Lin, Bingcheng
2009-09-01
A micropump-actuated negative pressure pinched injection method is developed for parallel electrophoresis on a multi-channel LIF detection system. The system has a home-made device that could individually control 16-port solenoid valves and a high-voltage power supply. The laser beam is excitated and distributes to the array separation channels for detection. The hybrid Glass-PDMS microfluidic chip comprises two common reservoirs, four separation channels coupled to their respective pneumatic micropumps and two reference channels. Due to use of pressure as a driving force, the proposed method has no sample bias effect for separation. There is only one high-voltage supply needed for separation without relying on the number of channels, which is significant for high-throughput analysis, and the time for sample loading is shortened to 1 s. In addition, the integrated micropumps can provide the versatile interface for coupling with other function units to satisfy the complicated demands. The performance is verified by separation of DNA marker and Hepatitis B virus DNA samples. And this method is also expected to show the potential throughput for the DNA analysis in the field of disease diagnosis. PMID:19681052
Study of valveless electromagnetic micropump by volume-of-fluid and OpenFOAM
Quang Dich, Nguyen; Dinh, Thien Xuan; Pham, Phuc Hong; Thanh Dau, Van
2015-05-01
The paper reports the first study on the backpressure of a valveless electromagnetic micropump using the volume-of-fluid (VOF) technique and open-source code OpenFOAM. The micropump consists of a vibrating diaphragm and fluidic microchannel connected to inlet and outlet tubes. The imbalance in fluid resistance of the fluidic microchannel during a vibration cycle of the diaphragm creates backpressure in the pump, which in turn produces a difference in water level between the inlet and outlet tubes. In this study, VOF was used in a transient simulation to obtain this difference in water level and then the backpressure. The obtained backpressure showed a slight discrepancy with the experimental data. The discrepancy was probably due to the difference in the wall surface quality of the fluidic microchannel between the simulation model and experimental device. These results are useful for analytical and numerical research on these types of micropumps and can easily be applied in an open-source code simulator with almost zero cost.
Peristaltic Pumping of Blood Through Small Vessels of Varying Cross-Section
Misra, J. C.; Maiti, S.
2012-11-01
The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered to be of varying cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. On the basis of the derived analytical expression, extensive numerical calculations have been made. The study reveals that velocity of blood and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude ratio and the value of the fluid index.
A. M. Abd-Alla
2014-01-01
Full Text Available In this paper, the peristaltic flow of a Jeffrey fluid in an asymmetric channel has been investigated. Mathematical modeling is carried out by utilizing long wavelength and low Reynolds number assumptions. Closed form expressions for the pressure gradient, pressure rise, stream function, axial velocity, and shear stress on the channel walls have been computed numerically. Effects of the Hartmann number, the ratio of relaxation to retardation times, time-mean flow, the phase angle and the gravity field on the pressure gradient, pressure rise, streamline, axial velocity, and shear stress are discussed in detail and shown graphically. The results indicate that the effect of Hartmann number, ratio of relaxation to retardation times, time-mean flow, phase angle, and gravity field are very pronounced in the peristaltic transport phenomena. Comparison was made with the results obtained in the presence and absence of magnetic field and gravity field.
Efficient worm-like locomotion: slip and control of soft-bodied peristaltic robots
In this work, we present a dynamic simulation of an earthworm-like robot moving in a pipe with radially symmetric Coulomb friction contact. Under these conditions, peristaltic locomotion is efficient if slip is minimized. We characterize ways to reduce slip-related losses in a constant-radius pipe. Using these principles, we can design controllers that can navigate pipes even with a narrowing in radius. We propose a stable heteroclinic channel controller that takes advantage of contact force feedback on each segment. In an example narrowing pipe, this controller loses 40% less energy to slip compared to the best-fit sine wave controller. The peristaltic locomotion with feedback also has greater speed and more consistent forward progress. (paper)
M. K. Chaube; Tripathi, D.; O. Anwar Bég; Shashi Sharma; PANDEY, V.S.
2015-01-01
A mathematical study on creeping flow of non-Newtonian fluids (power law model) through a nonuniform peristaltic channel, in which amplitude is varying across axial displacement, is presented, with slip effects included. The governing equations are simplified by employing the long wavelength and low Reynolds number approximations. The expressions for axial velocity, stream function, pressure gradient, and pressure difference are obtained. Computational and numerical results for velocity profi...
Dr.S.Ravi kumar
2013-01-01
In this paper we have analyzed the flow of a couple stress fluids in a channel bounded by flexible walls over which a traveling wave of contraction and expansion is imposed resulting in a peristaltic motion. An oscillatory time dependent flow is also imposed on this flow. The non-linear equations governing the flow through magnetic field are solved under long wavelength approximation. The existence of separation in the flow field is discussed for different values of the governing parameters. ...
Effect of induced magnetic field on peristaltic flow of a micropolar fluid in an asymmetric channel
Shit, G. C.; Roy, M.; E. Y. K. Ng
2010-01-01
Of concern in this paper is an investigation of peristaltic transport of a physiological fluid in an asymmetric channel under long wave length and low-Reynolds number assumptions. The flow is assumed to be incompressible, viscous, electrically conducting micropolar fluid and the effect of induced magnetic field is taken into account. Exact analytical solutions obtained for the axial velocity, microrotation component, stream line pattern, magnetic force function, axial-induced magnetic field a...
Peristaltic transport of Johnson-Segalman fluid under effect of a magnetic field
Moustafa Elshahed
2005-01-01
Full Text Available The peristaltic transport of Johnson-Segalman fluid by means of an infinite train of sinusoidal waves traveling along the walls of a two-dimensional flexible channel is investigated. The fluid is electrically conducted by a transverse magnetic field. A perturbation solution is obtained for the case in which amplitude ratio is small. Numerical results are reported for various values of the physical parameters of interest.
Non-Newtonian effects in the peristaltic flow of a Maxwell fluid
Tsiklauri, D.; Beresnev, I.
2001-01-01
We analyzed the effect of viscoelasticity on the dynamics of fluids in porous media by studying the flow of a Maxwell fluid in a circular tube, in which the flow is induced by a wave traveling on the tube wall. The present study investigates novelties brought about into the classic peristaltic mechanism by inclusion of non-Newtonian effects that are important, for example, for hydrocarbons. This problem has numerous applications in various branches of science, including stimulation of fluid f...
A Mathematical Model for Studying the Slip Effect on Peristaltic Motion with Heat and Mass Transfer
Tasawar Hayat; Najma Saleem; Awatif A. Hendi
2011-01-01
A mathematical model is presented with an interest to examine the peristaltic motion in an asymmetric channel by taking into account the slip, heat and mass transfer. Constitutive relationships for a micropolar fluid are used. The solution procedure for nonlinear analysis is given under long wavelength and low Reynolds number approximations. The effects of sundry parameters entering into the expressions of axial velocity,temperature and concentration are explored. Pumping and trapping phenomena are discussed.
Particle motion in unsteady two-dimensional peristaltic flow with application to the ureter
Jiménez-Lozano, Joel; Sen, Mihir; Dunn, Patrick F.
2009-04-01
Particle motion in an unsteady peristaltic fluid flow is analyzed. The fluid is incompressible and Newtonian in a two-dimensional planar geometry. A perturbation method based on a small ratio of wave height to wavelength is used to obtain a closed-form solution for the fluid velocity field. This analytical solution is used in conjunction with an equation of motion for a small rigid sphere in nonuniform flow taking Stokes drag, virtual mass, Faxén, Basset, and gravity forces into account. Fluid streamlines and velocity profiles are calculated. Theoretical values for pumping rates are compared with available experimental data. An application to ureteral peristaltic flow is considered since fluid flow in the ureter is sometimes accompanied by particles such as stones or bacteriuria. Particle trajectories for parameters that correspond to calcium oxalates for calculosis and Escherichia coli type for bacteria are analyzed. The findings show that retrograde or reflux motion of the particles is possible and bacterial transport can occur in the upper urinary tract when there is a partial occlusion of the wave. Dilute particle mixing is also investigated, and it is found that some of the particles participate in the formation of a recirculating bolus, and some of them are delayed in transit and eventually reach the walls. This can explain the failure of clearing residuals from the upper urinary tract calculi after successful extracorporeal shock wave lithotripsy. The results may also be relevant to the transport of other physiological fluids and industrial applications in which peristaltic pumping is used.
Peristaltic flow in non-uniform vessels of the micro-circulatory system
Maiti, S
2013-01-01
Of concern in the paper is generalized a theoretical study concerning the peristaltic flow of blood in the micro-circulatory system. The vessel is considered to be of non-uniform cross-section and blood to be a non-Newtonian fluid. The progressive wave front of the peristaltic flow is supposed sinusoidal/straight section dominated (SSD) (expansion/contraction type); Reynolds number is considered to be small with reference to the flow of physiological fluids. The non-Newtonian behaviour of blood is illustrated by considering the Herschel-Bulkley fluid model. The objective of the study has been to examine the effect of the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, wall shear stress, streamline pattern and trapping. Considerable quantitative differences between the results obtained for transport in two dimensional channel and an axisymmetric circular tube are noticed. The study shows that peristaltic pumping, flow velocity and wall shea...
Gastrointestinal monitor: automatic titration of jejunal inflow to match peristaltic outflow.
Moss, Gerald; Posada, Jose G
2007-06-15
A peristaltic gradient insures that chyme normally removed from the jejunal feeding site continues to be propelled caudad. The trigger for iatrogenic "feeding intolerance" is the inadvertently overwhelming of the jejunum's peristaltic outflow, even momentarily. Even minimum local stasis can stimulate a vagal reflex response. Motility of the sluggish gut further slows, leading to generalized abdominal distention, malaise, immobility, and impaired respiratory mechanics. Vagal vascular reflexes could explain the 1:1000 incidence of bowel necrosis for jejunally fed patients. We developed a clinical regimen that continuously "checks for residual" at the enteral feeding site, monitoring the adequacy of emptying. The jejunal inflow automatically is titrated to match peristaltic outflow if the latter cannot keep up. Intermittent suction aspirates the feeding catheter into a plastic chamber for 30 s. All swallowed air is removed efficiently within the close confines of the jejunal segment, without wasting digestive juices. The degassed aspirate is returned by gravity with the feedings during the second half of the 1-min cycle, unless incipient excess (>or=20 mL) fluid overflows. Only this relatively small volume of potentially excess fluid is discarded, forestalling the local distention. All patients tolerated immediate feeding without discomfort or abdominal distention, including three that had esophageal resection (including vagotomy) for carcinoma. Postoperative full enteral nutrition can be achieved quickly and safely with minimum attention, despite initially marginal gastrointestinal function. PMID:17509263
The Structure of Wheel Check Valve Influence on Air Block Phenomenon of Piezoelectric Micro-Pump
Song Chen; Yong Liu; Yanhu Shen; Jiantao Wang; Zhigang Yang
2015-01-01
To improve the stability and reliability of the piezoelectric micro-pump, the cause of air block phenomenon is analyzed on the structure of wheel check valve. During the movement of the bubble in the micro-channel, pressure drop occurs, the main factor which influences the bubble going through is opening height of the wheel check valve. Five groups of wheel check valves with different structures are used to test the wheel check valve opening height and air block probability. The experiment re...
Development and Application of a Diaphragm Micro-Pump with Piezoelectric Device
Ma, H K; Hou, B.R.; Wu, H Y; Lin, C.Y.; Gao, J. J.; Kou, M. C.
2008-01-01
In this study, a new type of thin, compact, and light weighed diaphragm micro-pump has been successfully developed to actuate the liquid by the vibration of a diaphragm. The micro-diaphragm pump with two valves is fabricated in an aluminum case by using highly accurate CNC machine, and the cross-section dimension is 5mm x 8mm. Both valves and diaphragm are manufactured from PDMS. The amplitude of vibration by a piezoelectric device produces an oscillating flow which may change the chamber vol...
Finite Element analysis of a shape memory alloy actuator for a micropump
Merzouki, Tarek; Duval, Arnaud; BEN ZINEB, Tarak
2012-01-01
This paper deals with a Finite Element (FE) behavior analysis of a shape memory alloy actuator for a micropump. It is composed of two membranes of NiTi shape memory alloy (SMA) in a martensitic state at room temperature. They have an initial flat shape and are bonded together with an intermediate spacer. The thermal loading allows the actuator to move up and down in the membrane normal direction. A detailed analysis of sensibility to material and geometric parameters of the SMA actuator is un...
An electrohydrodynamic (EHD) ion-drag micropump using three-dimensional carbon micromesh electrodes was developed. The carbon micromesh electrodes were created by the pyrolysis of SU-8 structures. The carbon electrodes and microchannel were formed on a quartz substrate, and the microchannel was sealed by an SU-8 slab structure. The pumping behaviors were evaluated using Fluorinert as a non-conductive sample solution. The maximum pressure and volume flow rate were approximately 23 Pa and 400 nL/min, respectively, under an applied voltage of 500 V. (paper)
Olesen, Laurits Højgaard; Bruus, Henrik; Ajdari, A.
2006-01-01
Recent experiments have demonstrated that ac electrokinetic micropumps permit integrable, local, and fast pumping (velocities similar to mm/s) with low driving voltage of a few volts only. However, they also displayed many quantitative and qualitative discrepancies with existing theories. We...... therefore extend the latter theories to account for three experimentally relevant effects: (i) vertical confinement of the pumping channel, (ii) Faradaic currents from electrochemical reactions at the electrodes, and (iii) nonlinear surface capacitance of the Debye layer. We report here that these effects...... indeed affect the pump performance in a way that we can rationalize by physical arguments....
Simulation of the fluidic features for diffuser/nozzle involved in a PZT-based valveless micropump
HouWensheng; Zheng Xiaolin; Biswajit Das; Jiang Yingtao; Qian Shizhi; Wu Xiaoying; Zheng Zhigao
2008-01-01
PZT-based valveless micropump is a microactuator that can be used for controlling and delivering tiny amounts of fluids, and diffuser/nozzle plays an important role when this type of micropump drives the fluid flowing along a specific direction. In this paper, a numerical model of micropump has been proposed, and the fluidic properties of diffuser/nozzle have been simulated with ANSYS. With the method of finite-element analysis, the increased pressure drop between inlet and outlet of diffuser/nozzle induces the increment of flow rate in both diffuser and nozzle simultaneously, but the increasing rate of diffuser is faster than that of nozzle. The L/R, ratio of L (length of cone pipe) and R (radius of minimal cross section of cone pipe) plays an important role in fluidic performance of diffuser and nozzle as well, and the mean flow rate will decrease with increment of L/R. The mean flow rate reaches its peak value when L/R with the value of 10 regardless the divergence angle of diffuser or nozzle. The simulation results indicate that the fluidic properties of diffuser/nozzle can be defined by its geometric structure, and accordingly determine the efficiency of micropump.
A Comparative Study of Nozzle/Diffuser Micropumps with Novel Valves
Jin-Cherng Shyu
2012-02-01
Full Text Available This study conducts an experimental study concerning the improvement of nozzle/diffuser micropump design using some novel no-moving-part valves. A total of three micropumps, including two enhancement structures having two-fin or obstacle structure and one conventional micro nozzle/diffuser design, are made and tested in this study. It is found that dramatic increase of the pressure drops across the designed micro nozzles/diffusers are seen when the obstacle or fin structure is added. The resultant maximum flow rates are 47.07 mm3/s and 53.39 mm3/s, respectively, for the conventional micro nozzle/diffuser and the added two-fin structure in micro nozzle/diffuser operated at a frequency of 400 Hz. Yet the mass flow rate for two-fin design surpasses that of conventional one when the frequency is below 425 Hz but the trend is reversed with a further increase of frequency. This is because the maximum efficiency ratio improvement for added two-fin is appreciably higher than the other design at a lower operating frequency. In the meantime, despite the efficiency ratio of the obstacle structure also reveals a similar trend as that of two-fin design, its significant pressure drop (flow resistance had offset its superiority at low operating frequency, thereby leading to a lesser flow rate throughout the test range.
Zhang, Rumi; Jullien, Graham A.; Dalton, Colin
2013-07-01
In this paper, we report on a modeling study of an AC electrothermal (ACET) micropump with high operating pressures as well as fast flow rates. One specific application area is for fluid delivery using microneedle arrays which require higher pressures and faster flow rates than have been previously reported with ACET devices. ACET is very suitable for accurate actuation and control of fluid flow, since the technique has been shown to be very effective in high conductivity fluids and has the ability to create a pulsation free flow. However, AC electrokinetic pumps usually can only generate low operating pressures of 1 to 100 Pa, where flow reversal is likely to occur with an external load. In order to realize a high performance ACET micropump for continuous fluid delivery, applying relatively high AC operating voltages (20 to 36 Vrms) to silicon substrate ACET actuators and using long serpentine channel allows the boosting of operating pressure as well as increasing the flow rates. Fast pumping flow rates (102-103 nl/s) and high operating pressures (1-12 kPa) can be achieved by applying both methods, making them of significant importance for continuous fluid delivery applications using microneedle arrays and other such biomedical devices.
In this paper the effects of induced magnetic field on the peristaltic transport of a Williamson fluid model in an asymmetric channel has been investigated. The problem is simplified by using long wave length and low Reynolds number approximations. The perturbation and numerical solutions have been presented. The expressions for pressure rise, pressure gradient, stream function, magnetic force function, current density distribution have been computed. The results of pertinent parameters have been discussed graphically. The trapping phenomena for different wave forms have been also discussed. - highlights: • The main motivation of this work is that we want to see the behavior of peristaltic flow of Williamson fluid in the occurrence of induced magnetic field. In literature no attempt is taken to discuss the lateral Numerical and analytical treatment on peristaltic flow of Williamson fluid in the occurrence of induced magnetic field. • We do not want to fill the gap in literature after studying this
A Peristaltic Micro Pump Driven by a Rotating Motor with Magnetically Attracted Steel Balls
Zhaoying Zhou; Kang Wu; Xiongying Ye; Min Du
2009-01-01
In this paper, we present a membrane peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls for lab-on-a-chip applications. The fabrication process is based on standard soft lithography technology and bonding of a PDMS layer with a PMMA substrate. A linear flow rate range ~490 μL/min was obtained by simply varying the rotation speed of a DC motor, and a maximum back pressure of 592 Pa was achieved at a rotation speed of 43 rpm. The flow rate of the pump can ...
Peristaltic transport of Conducting Bingham fluid in contact with a Newtonian fluid in a channel
M.Arun kumar
2013-04-01
Full Text Available Peristaltic pumping by a sinusoidal traveling wave in the walls of a two dimensional channel filled with two immiscible fluids with magnetic effect is investigated. The core region of the channel is occupied by a Bingham fluid where as the peripheral region is occupied by a Newtonian fluid. The flow is examined in a wave frame of reference moving with the velocity of the wave. The expressions for the stream function, the velocity and the pressure rise are obtained. The equation for the interface separating the two fluids is obtained. Numerical results are reported for several of the physical parameters of interest. We observed that the lower values of
Magnetohydrodynamic Peristaltic Flow of a Pseudoplastic Fluid in a Curved Channel
Noreen, Saima; Hayat, Tasawar; Alsaedi, Ahmed
2013-05-01
A mathematical model is developed to examine the effects of an induced magnetic field on the peristaltic flow in a curved channel. The non-Newtonian pseudoplastic fluid model is used to depict the combined elastic and viscous properties. The analysis has been carried out in the wave frame of reference, long wavelength and low Reynolds scheme are implemented. A series solution is obtained through perturbation analysis. Results for stream function, pressure gradient, magnetic force function, induced magnetic field, and current density are constructed. The effects of significant parameters on the flow quantities are sketched and discussed.
Hayat, T.; Iqbal, Rija; Tanveer, Anum; Alsaedi, A.
2016-06-01
This paper looks at the influences of magnetohydrodynamics (MHD) and thermal radiation on peristaltic transport of a pseudoplastic nanofluid in a tapered asymmetric channel. The tapered channel walls satisfy convective boundary conditions. The governing equations for the balance of mass, momentum, temperature and volume fraction for pseudoplastic nanofluid are first formulated and then utilized for long wavelength and small Reynolds number considerations. Effects of involved parameters on the flow characteristics have been plotted and examined. It is observed that the heat transfer Biot number shows a dual behavior on the temperature of nanofluid particles whereas the mass transfer Biot number with its increasing values enhances the fluid temperature.
Peristaltic flow in an asymmetric channel with convective boundary conditions and Joule heating
Abbasi Fahad Munir; Hayat Tasawar; Ahmad Bashir
2014-01-01
The peristaltic transport of viscous fluid in an asymmetric channel is concentrated. The channel walls exhibit convective boundary conditions. Both cases of hydrodynamic and magnetohydrodynamic (MHD) fluids are considered. Mathematical analysis has been presented in a wave frame of reference. The resulting problems are non-dimensionalized. Long wavelength and low Reynolds number approximations are employed. Joule heating effect on the thermal equation is retained. Analytic solutions for stream function and temperature are constructed. Numerical integration is carried out for pressure rise per wavelength. Effects of influential flow parameters have been pointed out through graphs.
Sohail Nadeem; Safia Akram
2011-01-01
In the present paper we discuss the magnetohydrodynamic (MHD) peristaltic flow of a hyperbolic tangent fluid model in a vertical asymmetric channel under a zero Reynolds number and long wavelength approximation. Exact solution of the temperature equation in the absence of dissipation term has been computed and the analytical expression for stream function and axial pressure gradient are established. The flow is analyzed in a wave frame of reference moving with the velocity of wave. The expression for pressure rise has been computed numerically. The physical features of pertinent parameters are analyzed by plotting graphs and discussed in detail.
Rachid, Hassan
2015-12-01
In the present study,we investigate the unsteady peristaltic transport of a viscoelastic fluid with fractional Burgers' model in an inclined tube. We suppose that the viscosity is variable in the radial direction. This analysis has been carried out under low Reynolds number and long-wavelength approximations. An analytical solution to the problem is obtained using a fractional calculus approach. Figures are plotted to show the effects of angle of inclination, Reynolds number, Froude number, material constants, fractional parameters, parameter of viscosity and amplitude ratio on the pressure gradient, pressure rise, friction force, axial velocity and on the mechanical efficiency.
Mixed convection peristaltic flow of third order nanofluid with an induced magnetic field.
Saima Noreen
Full Text Available This research is concerned with the peristaltic flow of third order nanofluid in an asymmetric channel. The governing equations of third order nanofluid are modelled in wave frame of reference. Effect of induced magnetic field is considered. Long wavelength and low Reynolds number situation is tackled. Numerical solutions of the governing problem are computed and analyzed. The effects of Brownian motion and thermophoretic diffusion of nano particles are particularly emphasized. Physical quantities such as velocity, pressure rise, temperature, induced magnetic field and concentration distributions are discussed.
Peristaltic flow of Johnson-Segalman fluid in asymmetric channel with convective boundary conditions
H YASMIN; T HAYAT; A ALSAEDI; HH ALSULAMI
2014-01-01
This work is concerned with the peristaltic transport of the Johnson-Segalman fluid in an asymmetric channel with convective boundary conditions. The mathematical modeling is based upon the conservation laws of mass, linear momentum, and energy. The resulting equations are solved after long wavelength and low Reynolds number are used. The results for the axial pressure gradient, velocity, and temperature profiles are obtained for small Weissenberg number. The expressions of the pressure gra-dient, velocity, and temperature are analyzed for various embedded parameters. Pumping and trapping phenomena are also explored.
Effect of Slip on Peristaltic Flow of Powell-Eyring Fluid in a Symmetric Channel
T. Hayat
2014-01-01
Full Text Available Peristaltic flow of non-Newtonian fluid in a symmetric channel with partial slip effect is examined. The non-Newtonian behavior of fluid is characterized by the constitutive equations of Powell-Eyring fluid. The motion is induced by a sinusoidal wave traveling along the flexible walls of channel. The flow is analyzed in a wave frame of reference moving with the velocity of wave. The equations governing the flow are solved by adopting lubrication approach. Series solutions for the stream function and axial pressure gradient are obtained. Impact of slip and other emerging flow parameters is plotted and analyzed graphically.
Radiative Peristaltic Flow of Jeffrey Nanofluid with Slip Conditions and Joule Heating
Hayat, Tasawar; Shafique, Maryam; Tanveer, Anum; Alsaedi, Ahmed
2016-01-01
Mixed convection peristaltic flow of Jeffrey nanofluid in a channel with compliant walls is addressed here. The present investigation includes the viscous dissipation, thermal radiation and Joule heating. Whole analysis is performed for velocity, thermal and concentration slip conditions. Related problems through long wavelength and low Reynolds number are examined for stream function, temperature and concentration. Impacts of thermal radiation, Hartman number, Brownian motion parameter, thermophoresis, Joule heating and slip parameters are explored in detail. Clearly temperature is a decreasing function of Hartman number and radiation parameter. PMID:26886919
Akbar, Noreen Sher
2016-03-01
The peristaltic flow of an incompressible viscous fluid containing copper nanoparticles in an asymmetric channel is discussed with thermal and velocity slip effects. The copper nanoparticles for the peristaltic flow water as base fluid is not explored so far. The equations for the purposed fluid model are developed first time in literature and simplified using long wavelength and low Reynolds number assumptions. Exact solutions have been calculated for velocity, pressure gradient, the solid volume fraction of the nanoparticles and temperature profile. The influence of various flow parameters on the flow and heat transfer characteristics is obtained.
Sher Akbar, Noreen
2015-03-01
The influence of magnetic field on peristaltic flow of a Casson fluid model is considered. The model for peristaltic literature is modelled first time. The governing coupled equations are constructed under long wavelength and low Reynold's number approximation. Exact solutions are evaluated for stream function and pressure gradient. The important findings in this study are the variation of the Hartmann number M, Casson fluid parameter ζ and amplitudes a, b, d and ϕ. The velocity field increases due to increase in Hartmann number M near the channel walls while velocity field decreases at the centre of the channel.
Hayat, Tasawar; Rafiq, Maimona; Ahmad, Bashir
2016-01-01
The objective of present paper is to examine the peristaltic flow of magnetohydrodynamic (MHD) Jeffrey fluid saturating porous space in a channel through rotating frame. Unlike the previous attempts, the flow formulation is based upon modified Darcy's law porous medium effect in Jeffrey fluid situation. In addition the impacts due to Soret and Dufour effects in the radiative peristaltic flow are accounted. Rosseland’s approximation has been utilized for the thermal radiative heat flux. Lubrication approach is implemented for the simplification. Resulting problems are solved for the stream function, temperature and concentration. Graphical results are prepared and analyzed for different parameters of interest entering into the problems. PMID:26808387
Hayat, Tasawar; Rafiq, Maimona; Ahmad, Bashir
2016-01-01
The objective of present paper is to examine the peristaltic flow of magnetohydrodynamic (MHD) Jeffrey fluid saturating porous space in a channel through rotating frame. Unlike the previous attempts, the flow formulation is based upon modified Darcy's law porous medium effect in Jeffrey fluid situation. In addition the impacts due to Soret and Dufour effects in the radiative peristaltic flow are accounted. Rosseland's approximation has been utilized for the thermal radiative heat flux. Lubrication approach is implemented for the simplification. Resulting problems are solved for the stream function, temperature and concentration. Graphical results are prepared and analyzed for different parameters of interest entering into the problems. PMID:26808387
Design and Analysis of Piezoelectric Micro-Pump Using Traveling-Wave
Since the development of microelectromechanical systems (MEMS) technology for the medical field, various micro-fluid transfer systems have been studied. This paper proposes a micro-piezoelectric pump that imitates a stomach's peristalsis by using two separate piezoelectric elements, in contrast to existing micro-pumps. This piezoelectric pump is operated by using the valve-less traveling wave of peristalsis movement. If the piezoelectric plates at the two separated plates are actuated at the input voltage, a traveling wave occurs between the two plates. Then, the fluid migrates by the pressure difference generated by the traveling wave. Finite element analysis was performed to understand the mechanics of the combined system with piezoelectric elements, elastic structures, and fluids. The effects of design variables such as the chamber height and number of ceramics on the flow rate of the fluid were examined
Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields
This paper presents a centrifugal force based magnetic micro-pump for the pumping of blood. Most blood pumps are driven by an electrical motor with wired control. To develop a wireless and battery-free blood pump, the proposed pump is controlled by external rotating magnetic fields with a synchronized impeller. Synchronization occurs because the rotor is divided into multi-stage impeller parts and NdFeB permanent magnet. Finally, liquid is discharged by the centrifugal force of multi-stage impeller. The proposed pump length is 30 mm long and 19 mm in diameter which much smaller than currently pumps; however, its pumping ability satisfies the requirement for a blood pump. The maximum pressure is 120 mmHg and the maximum flow rate is 5000ml/min at 100 Hz. The advantage of the proposed pump is that the general mechanical problems of a normal blood pump are eliminated by the proposed driving mechanism.
Characteristics of electrostatic gas micro-pump with integrated polyimide passive valves
We report on the fabrication and characterization of electrostatic gas micro-pumps integrated with polyimide check valves. Touch-mode capacitance actuation, enabled by a fixed silicon electrode and a metal/polyimide diaphragm, creates the suction and push-out of the ambient gas; the gas flow is rectified by the check valves located at the inlet and outlet of the pump. The fabricated pumps were tested with various actuation voltages at different frequencies and duty cycles; an emphasis was placed on investigating the effect of valve flow conductance on the gas pumping characteristics. The pump with higher valve conductance could increase the operating frequency of the pump and affect the pumping characteristics from a pulsating flow to a continuous flow, leading to a higher gas flow rate. This electrostatic pump has a flow control resolution of 1 µL min−1; it could generate a gas flow up to 106 µL min−1. (paper)
Characteristics of electrostatic gas micro-pump with integrated polyimide passive valves
Han, Jeahyeong; Yeom, Junghoon; Mensing, Glennys; Flachsbart, Bruce; Shannon, Mark A.
2012-09-01
We report on the fabrication and characterization of electrostatic gas micro-pumps integrated with polyimide check valves. Touch-mode capacitance actuation, enabled by a fixed silicon electrode and a metal/polyimide diaphragm, creates the suction and push-out of the ambient gas; the gas flow is rectified by the check valves located at the inlet and outlet of the pump. The fabricated pumps were tested with various actuation voltages at different frequencies and duty cycles; an emphasis was placed on investigating the effect of valve flow conductance on the gas pumping characteristics. The pump with higher valve conductance could increase the operating frequency of the pump and affect the pumping characteristics from a pulsating flow to a continuous flow, leading to a higher gas flow rate. This electrostatic pump has a flow control resolution of 1 µL min-1 it could generate a gas flow up to 106 µL min-1.
NUMERICAL STUDY OF PERIODICAL FLOWS OF PIEZOELECTRIC VALVELESS MICROPUMP FOR BIOCHIPS
ZHANG Yong-li; WU Jian-kang
2005-01-01
Shallow water model was employed to approximate the three-dimensional flows of a thin micropump to a two-dimensional thickness-averaged flows. The finite element method and pressure correction algorithm were used to solve the twodimensional flows of the pump and calculate the pump flow rate. The numerical results indicate that: 1 ) Phase differences in time of flow velocities and backflows occur across section of diffuser connecting to pump chamber; 2 ) A pair of symmetric vortexes appear inside the pump chamber at the end of suction flow phase; 3) The directional flow rate of the pump is dominated by nonlinearity of Navier-Stokes equations.Quantitative relations of the pump flow rate versus the ratio of diffuser length to width,the ratio of diffuser thickness to width, fluid viscosity and backpressure were also given. Possibly maximal flow rate can be achieved by optimizing the pump parameters.
A magnetic shape memory micropump: contact-free, and compatible with PCR and human DNA profiling
Ullakko, K.; Wendell, L.; Smith, A.; Müllner, P.; Hampikian, G.
2012-11-01
Magnetic shape memory (MSM) Ni-Mn-Ga elements are relatively new materials with a variety of remarkable properties. They respond to changes in magnetic fields by elongating and shortening up to 6%. We have constructed a micropump which consists principally of a single component, the MSM element. The pump can be driven by the rotation of a diametrically magnetized cylindrical magnet or by an electrical rotation of the magnetic field; it is reversible, and can be effectively operated by hand without any electrical power. The MSM element does not inhibit the polymerase chain reaction. We demonstrate that it is compatible with forensic applications and show that it does not inhibit human DNA profiling. This novel pump is suitable for lab-on-a-chip applications that require microfluidics.
A novel fabrication process to realize a valveless micropump on a flexible substrate
Wei, Yang; Torah, Russel; Yang, Kai; Beeby, Steve; Tudor, John
2014-02-01
This paper reports, for the first time, on the design, fabrication and testing of a planar valveless micropump, entirely screen printed onto a flexible polyimide (Kapton) substrate using sacrificial, structural, conductive and piezoelectric layers. The sacrificial layer, used to achieve a pump chamber and inlet/outlet channels, is removed using water followed by a 140 ° C heat treatment to evaporate the water from the structure. The fabrication process is analogous to a standard silicon based micro-electro-mechanical system sacrificial process. Applying a sinusoidal AC voltage to the piezoelectric layer drives a flexible membrane which pumps a liquid through the chamber. A maximum flow rate of 38 μl min-1 was achieved using a drive frequency of 3 kHz.
A magnetic shape memory micropump: contact-free, and compatible with PCR and human DNA profiling
Magnetic shape memory (MSM) Ni–Mn–Ga elements are relatively new materials with a variety of remarkable properties. They respond to changes in magnetic fields by elongating and shortening up to 6%. We have constructed a micropump which consists principally of a single component, the MSM element. The pump can be driven by the rotation of a diametrically magnetized cylindrical magnet or by an electrical rotation of the magnetic field; it is reversible, and can be effectively operated by hand without any electrical power. The MSM element does not inhibit the polymerase chain reaction. We demonstrate that it is compatible with forensic applications and show that it does not inhibit human DNA profiling. This novel pump is suitable for lab-on-a-chip applications that require microfluidics. (paper)
Topology and shape optimization of induced-charge electro-osmotic micropumps
Gregersen, Misha Marie; Okkels, Fridolin; Bazant, M. Z.; Bruus, Henrik
2009-01-01
For a dielectric solid surrounded by an electrolyte and positioned inside an externally biased parallel-plate capacitor, we study numerically how the resulting induced-charge electro-osmotic (ICEO) flow depends on the topology and shape of the dielectric solid. In particular, we extend existing...... conventional electrokinetic models with an artificial design field to describe the transition from the liquid electrolyte to the solid dielectric. Using this design field, we have succeeded in applying the method of topology optimization to find system geometries with non-trivial topologies that maximize the...... design field. Our results show the importance of the topology and shape of the dielectric solid in ICEO systems and point to new designs of ICEO micropumps with significantly improved performance....
Experimental study of thermally-driven micro-pump using stepped laser
ZHOU Hong; HUAI Xiulan; LI Huazhi; LIU Dengying; MENG Qun
2004-01-01
The stepped pulse-laser is used to heat the fluid in a micro-tube with the diameter less than 1 mm, and a phase change and a directional flow of the fluid are induced. Based on many experimental observations, the mechanism of thermally-driven MEMS is studied and the technical approaches of the efficient and steady thermally-driven flow is given. The experimental results show that the hypostasis of the thermally-driven micro-pump is a kind of erratic liquid-vapor two-phase flow, and the liquid movement and the change rate of the pressure is closely related to the bubbles' behavior in the micro-tube.
Li, Xuequan; Liu, Mengmeng; Huang, Baisheng; Liu, Hong; Hu, Weiguo; Shao, Li-Hua; Wang, Zhong Lin
2016-01-01
We firstly designed an electrochemical system for dealloying to synthesize nanoporous gold (NPG) and also driving the novel NPG based actuator by utilizing a modified rotary triboelectric nanogenerator (TENG). Compared to the previous reported TENG whose outputs decline due to temperature rising resulting from electrodes friction, the modified TENG with a cooling system has stable output current and voltage increased by 14% and 20%, respectively. The novel cantilevered hybrid actuator characterised by light-weight (ca. 3 mg) and small volume (ca. 30 mm × 2 mm × 10 μm) is driven by a microcontroller modulated TENG with the displacement of 2.2 mm, which is about 106 times larger than that of traditional cantilever using planar surfaces. The energy conversion efficiencies defined as the energy consumed during dealloying and actuation compared with the output of TENG are 47% and 56.7%, respectively. PMID:27063987
In this paper, the peristaltic flow of a Jeffrey fluid in an asymmetric rotating channel is studied. Mathematical modeling is carried out by utilizing long wavelength and low Reynolds number assumptions. Closed form expressions for the pressure gradient, pressure rise, streamlines, axial velocity and shear stress on the channel walls have been computed numerically. Effects of Hartmann number, the ratio of relaxation to retardation times, time-mean flow, rotation and the phase angle on the pressure gradient, pressure rise, streamline, axial velocity and shear stress are discussed in detail and shown graphically. The results indicate that the effect of the Hartmann number, the ratio of relaxation to retardation times, time-mean flow, rotation and the phase angle are very pronounced in the phenomena. Comparison was made with the results obtained in the asymmetric channel and symmetric channel. - Highlights: • The peristaltic flow of a Jeffrey fluid in an asymmetric rotating channel with magnetic field. • Mathematical modeling for long wavelength and low Reynolds number assumptions. • Closed form expressions for the pressure gradient, pressure rise, stream function, axial velocity and shear stress
Williamson Fluid Model for the Peristaltic Flow of Chyme in Small Intestine
Sohail Nadeem
2012-01-01
Full Text Available Mathematical model for the peristaltic flow of chyme in small intestine along with inserted endoscope is considered. Here, chyme is treated as Williamson fluid, and the flow is considered between the annular region formed by two concentric tubes (i.e., outer tube as small intestine and inner tube as endoscope. Flow is induced by two sinusoidal peristaltic waves of different wave lengths, traveling down the intestinal wall with the same speed. The governing equations of Williamson fluid in cylindrical coordinates have been modeled. The resulting nonlinear momentum equations are simplified using long wavelength and low Reynolds number approximations. The resulting problem is solved using regular perturbation method in terms of a variant of Weissenberg number We. The numerical solution of the problem is also computed by using shooting method, and comparison of results of both solutions for velocity field is presented. The expressions for axial velocity, frictional force, pressure rise, stream function, and axial pressure gradient are obtained, and the effects of various emerging parameters on the flow characteristics are illustrated graphically. Furthermore, the streamlines pattern is plotted, and it is observed that trapping occurs, and the size of the trapped bolus varies with varying embedded flow parameters.
Slip Effects on Peristaltic Transport of a Particle-Fluid Suspension in a Planar Channel
Mohammed H. Kamel
2015-01-01
Full Text Available Peristaltic pumping induced by a sinusoidal traveling wave in the walls of a two-dimensional channel filled with a viscous incompressible fluid mixed with rigid spherical particles is investigated theoretically taking the slip effect on the wall into account. A perturbation solution is obtained which satisfies the momentum equations for the case in which amplitude ratio (wave amplitude/channel half width is small. The analysis has been carried out by duly accounting for the nonlinear convective acceleration terms and the slip condition for the fluid part on the wavy wall. The governing equations are developed up to the second order of the amplitude ratio. The zeroth-order terms yield the Poiseuille flow and the first-order terms give the Orr-Sommerfeld equation. The results show that the slip conditions have significant effect within certain range of concentration. The phenomenon of reflux (the mean flow reversal is discussed under slip conditions. It is found that the critical reflux pressure is lower for the particle-fluid suspension than for the particle-free fluid and is affected by slip condition. A motivation of the present analysis has been the hope that such theory of two-phase flow process under slip condition is very useful in understanding the role of peristaltic muscular contraction in transporting biofluid behaving like a particle-fluid mixture. Also the theory is important to the engineering applications of pumping solid-fluid mixture by peristalsis.
Peristaltic Transport of a Rheological Fluid: Model for Movement of Food Bolus Through Esophagus
Misra, J C
2011-01-01
Fluid mechanical peristaltic transport through esophagus has been of concern in the paper. A mathematical model has been developed with an aim to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed with the specific aim of exploring some important information concerning the movement of food bolus through the esophagus. The analysis has been carried out by using lubrication theory. The study is particularly suitable for cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes places by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocity, particle trajectory and reflux are investigated for a single wave as well as for a train of periodic per...
Tripathi, Dharmendra; Bég, O Anwar
2012-08-01
Magnetohydrodynamic peristaltic flows arise in controlled magnetic drug targeting, hybrid haemodynamic pumps and biomagnetic phenomena interacting with the human digestive system. Motivated by the objective of improving an understanding of the complex fluid dynamics in such flows, we consider in the present article the transient magneto-fluid flow and heat transfer through a finite length channel by peristaltic pumping. Reynolds number is small enough and the wavelength to diameter ratio is large enough to negate inertial effects. Analytical solutions for temperature field, axial velocity, transverse velocity, pressure gradient, local wall shear stress, volume flowrate and averaged volume flowrate are obtained. The effects of the transverse magnetic field, Grashof number and thermal conductivity on the flow patterns induced by peristaltic waves (sinusoidal propagation along the length of channel) are studied using graphical plots. The present study identifies that greater pressure is required to propel the magneto-fluid by peristaltic pumping in comparison to a non-conducting Newtonian fluid, whereas, a lower pressure is required if heat transfer is effective. The analytical solutions further provide an important benchmark for future numerical simulations. PMID:23057236
The influence of magnetic field on peristaltic flow of a Casson fluid model is considered. The model for peristaltic literature is modelled first time. The governing coupled equations are constructed under long wavelength and low Reynold's number approximation. Exact solutions are evaluated for stream function and pressure gradient. The important findings in this study are the variation of the Hartmann number M, Casson fluid parameter ζ and amplitudes a, b, d and ϕ. The velocity field increases due to increase in Hartmann number M near the channel walls while velocity field decreases at the centre of the channel. - Highlights: • The influence of magnetic field on peristaltic flow of a Casson fluid model is considered. • The model for peristaltic literature is modelled first time. • The governing coupled equations are constructed under long wavelength and low Reynold's number approximation. • Exact solutions are evaluated for stream function and pressure gradient. • The velocity field increases due to increase in Hartmann number M near the channel walls while velocity field decreases at the centre of the channel
Tseng, Li-Yu; Yang, An-Shik; Lee, Chun-Ying; Cheng, Chiang-Ho
2013-08-01
To meet a growing need in biological and medical applications, innovative micro-electro-mechanical system (MEMS) technologies have realized important progress on the micropump as one of the essential fluid handling devices to deliver and control precise amounts of fluid flowing along a specific direction. This research proposes a piezoelectric (PZT) valveless micropump adopting an integrated diffuser/nozzle bulge-piece design. The pump mainly consisted of a stainless-steel structured chamber with dimensions of 8 mm in diameter and 70 μm in depth to enhance its long-term reliability, low-cost production, and maximized liquid compatibility. A PZT diaphragm was also used as a driving source to propel the liquid stream under actuation. As commonly used indices to describe pump operation, the delivered volumetric flow rates and pressures were determined at bulge-piece diameters of 2, 4 and 6 mm, with a driving voltage of 160 Vpp and frequency ranging from 50 to 550 Hz. Measurements and simulations have successfully shown that this micropump is capable of operating at a greater volumetric flow rate of up to 1.2 ml min-1 with a maximum back pressure of 5.3 kPa. In addition, the time-recurring flow behavior in the chamber and its relationship to the pumping performance were examined in detail.
To meet a growing need in biological and medical applications, innovative micro-electro-mechanical system (MEMS) technologies have realized important progress on the micropump as one of the essential fluid handling devices to deliver and control precise amounts of fluid flowing along a specific direction. This research proposes a piezoelectric (PZT) valveless micropump adopting an integrated diffuser/nozzle bulge-piece design. The pump mainly consisted of a stainless-steel structured chamber with dimensions of 8 mm in diameter and 70 μm in depth to enhance its long-term reliability, low-cost production, and maximized liquid compatibility. A PZT diaphragm was also used as a driving source to propel the liquid stream under actuation. As commonly used indices to describe pump operation, the delivered volumetric flow rates and pressures were determined at bulge-piece diameters of 2, 4 and 6 mm, with a driving voltage of 160 Vpp and frequency ranging from 50 to 550 Hz. Measurements and simulations have successfully shown that this micropump is capable of operating at a greater volumetric flow rate of up to 1.2 ml min−1 with a maximum back pressure of 5.3 kPa. In addition, the time-recurring flow behavior in the chamber and its relationship to the pumping performance were examined in detail. (paper)
A Mathematical Model for Peristaltic Transport of Micro-Polar Fluids
S. K. Pandey
2011-01-01
Full Text Available A mathematical model has been constructed for peristaltic transport of micro-polar fluid in a circular cylindrical tube of finite length by letting sinusoidal waves propagate along the wall that induce contraction and relaxation but not expansion beyond the natural boundary. Axial and radial velocities and micro-rotation components are formulated for micro-polar fluid transportations by applying the method of long wavelength and low Reynolds number approximations in the analysis. Pressure distribution along the tube length is studied to investigate temporal effects. An in-depth study has been done to learn the effects of coupling number and micro-polar parameter. The effects of coupling number and micro-polar parameter are investigated also on mechanical efficiency, reflux and trapping. A significant difference observed is that unlike integral wave-trains propagating along the tube walls that have identical peaks of pressure, non-integral wave-trains have peaks of different sizes.
Simulations of peristaltic slip-flow of hydromagnetic bio-fluid in a curved channel
N. Ali
2016-02-01
Full Text Available The influence of slip and magnetic field on transport characteristics of a bio-fluid are analyzed in a curved channel. The problem is modeled in curvilinear coordinate system under the assumption that the wavelength of the peristaltic wave is larger in magnitude compared to the width of the channel. The resulting nonlinear boundary value problem (BVP is solved using an implicit finite difference technique (FDT. The flow velocity, pressure rise per wavelength and stream function are illustrated through graphs for various values of rheological and geometrical parameters of the problem. The study reveals that a thin boundary layer exists at the channel wall for strong magnetic field. Moreover, small values of Weissenberg number counteract the curvature and make the velocity profile symmetric. It is also observed that pressure rise per wavelength in pumping region increases (decreases by increasing magnetic field, Weissenberg number and curvature of the channel (slip parameter.
A peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls.
Du, Min; Ye, Xiongying; Wu, Kang; Zhou, Zhaoying
2009-01-01
In this paper, we present a membrane peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls for lab-on-a-chip applications. The fabrication process is based on standard soft lithography technology and bonding of a PDMS layer with a PMMA substrate. A linear flow rate range ∼490 μL/min was obtained by simply varying the rotation speed of a DC motor, and a maximum back pressure of 592 Pa was achieved at a rotation speed of 43 rpm. The flow rate of the pump can also be adjusted by using steel balls with different diameters or changing the number of balls. Nevertheless, the micro pump can also work in high speed mode. A high back pressure up to 10 kPa was achieved at 500 rpm using a high speed DC motor, and an utmost flow rate up to 5 mL/min was reached. PMID:22574035
Simulations of peristaltic slip-flow of hydromagnetic bio-fluid in a curved channel
Ali, N.; Javid, K.; Sajid, M.
2016-02-01
The influence of slip and magnetic field on transport characteristics of a bio-fluid are analyzed in a curved channel. The problem is modeled in curvilinear coordinate system under the assumption that the wavelength of the peristaltic wave is larger in magnitude compared to the width of the channel. The resulting nonlinear boundary value problem (BVP) is solved using an implicit finite difference technique (FDT). The flow velocity, pressure rise per wavelength and stream function are illustrated through graphs for various values of rheological and geometrical parameters of the problem. The study reveals that a thin boundary layer exists at the channel wall for strong magnetic field. Moreover, small values of Weissenberg number counteract the curvature and make the velocity profile symmetric. It is also observed that pressure rise per wavelength in pumping region increases (decreases) by increasing magnetic field, Weissenberg number and curvature of the channel (slip parameter).
Effect of induced magnetic field on peristaltic flow of a micropolar fluid in an asymmetric channel
Shit, G C; Ng, E Y K; 10.1002/cnm.1397
2010-01-01
Of concern in this paper is an investigation of peristaltic transport of a physiological fluid in an asymmetric channel under long wave length and low-Reynolds number assumptions. The flow is assumed to be incompressible, viscous, electrically conducting micropolar fluid and the effect of induced magnetic field is taken into account. Exact analytical solutions obtained for the axial velocity, microrotation component, stream line pattern, magnetic force function, axial-induced magnetic field as well as the current density distribution across the channel. The flow phenomena for the pumping characteristics, trapping and reflux are also investigated. The results presented reveal that the velocity decreases with the increase of magnetic field as well as the coupling parameter. Moreover, the trapping fluid can be eliminated by the application of an external magnetic field. Thus, the study bears the promise of important applications in physiological systems.
Convective boundary conditions effect on peristaltic flow of a MHD Jeffery nanofluid
Kothandapani, M.; Prakash, J.
2016-03-01
This work is aimed at describing the influences of MHD, chemical reaction, thermal radiation and heat source/sink parameter on peristaltic flow of Jeffery nanofluids in a tapered asymmetric channel along with slip and convective boundary conditions. The governing equations of a nanofluid are first formulated and then simplified under long-wavelength and low-Reynolds number approaches. The equation of nanoparticles temperature and concentration is coupled; hence, homotopy perturbation method has been used to obtain the solutions of temperature and concentration of nanoparticles. Analytical solutions for axial velocity, stream function and pressure gradient have also constructed. Effects of various influential flow parameters have been pointed out through with help of the graphs. Analysis indicates that the temperature of nanofluids decreases for a given increase in heat transfer Biot number and chemical reaction parameter, but it possesses converse behavior in respect of mass transfer Biot number and heat source/sink parameter.
Non-Newtonian effects in the peristaltic flow of a Maxwell fluid
Tsiklauri, D
2001-01-01
We analyzed the effect of viscoelasticity on the dynamics of fluids in porous media by studying the flow of a Maxwell fluid in a circular tube, in which the flow is induced by a wave traveling on the tube wall. The present study investigates novelties brought about into the classic peristaltic mechanism by inclusion of non-Newtonian effects that are important, for example, for hydrocarbons. This problem has numerous applications in various branches of science, including stimulation of fluid flow in porous media under the effect of elastic waves. We have found that in the extreme non-Newtonian regime there is a possibility of a fluid flow in the direction {\\it opposite} to the propagation of the wave traveling on the tube wall.
Peristaltic motion of Johnson-Segalman fluid in a curved channel with slip conditions.
Sadia Hina
Full Text Available Slip effects on the peristaltic transport of Johnson-Segalman fluid through a curved channel have been addressed. The influence of wall properties is also analyzed. Long wavelength and low Reynolds number assumptions have been utilized in the mathematical formulation of the problem. The equations so formed have been solved numerically by shooting method through computational software Mathematica 8. In addition the analytic solution for small Weissenberg number (elastic parameter is computed through a regular perturbation method. An excellent agreement is noticed between the two solutions. The results indicate an increase in the magnitude of velocity with an intensification in the slip effect. Moreover the size and circulation of the trapped boluses increase with an increase in the slip parameter. Unlike the planar channel, the profiles of axial velocity are not symmetric about the central line of the channel.
Hayat, T. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Department of Mathematics, King Abdulaziz University, P.O. Box 80257, Jeddah 21589 (Saudi Arabia); Nisar, Z. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Ahmad, B. [Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Department of Mathematics, King Abdulaziz University, P.O. Box 80257, Jeddah 21589 (Saudi Arabia); Yasmin, H., E-mail: qau2011@gmail.com [Department of Mathematics, COMSATS Institute of Information Technology, G.T. Road, Wah Cantt 47040 (Pakistan)
2015-12-01
This paper is devoted to the magnetohydrodynamic (MHD) peristaltic transport of nanofluid in a channel with wall properties. Flow analysis is addressed in the presence of viscous dissipation, partial slip and Joule heating effects. Mathematical modelling also includes the salient features of Brownian motion and thermophoresis. Both analytic and numerical solutions are provided. Comparison between the solutions is shown in a very good agreement. Attention is focused to the Brownian motion parameter, thermophoresis parameter, Hartman number, Eckert number and Prandtl number. Influences of various parameters on skin friction coefficient, Nusselt and Sherwood numbers are also investigated. It is found that both the temperature and nanoparticles concentration are increasing functions of Brownian motion and thermophoresis parameters. - Highlights: • Temperature rises when Brownian motion and thermophoresis effects intensify. • Temperature profile increases when thermal slip parameter increases. • Concentration field is a decreasing function of concentration slip parameter. • Temperature decreases whereas concentration increases for Hartman number.
Peristaltic Transport of Prandtl-Eyring Liquid in a Convectively Heated Curved Channel.
Hayat, Tasawar; Bibi, Shahida; Alsaadi, Fuad; Rafiq, Maimona
2016-01-01
Here peristaltic activity for flow of a Prandtl-Eyring material is modeled and analyzed for curved geometry. Heat transfer analysis is studied using more generalized convective conditions. The channel walls satisfy complaint walls properties. Viscous dissipation in the thermal equation accounted. Unlike the previous studies is for uniform magnetic field on this topic, the radial applied magnetic field has been utilized in the problems development. Solutions for stream function (ψ), velocity (u), and temperature (θ) for small parameter β have been derived. The salient features of heat transfer coefficient Z and trapping are also discussed for various parameters of interest including magnetic field, curvature, material parameters of fluid, Brinkman, Biot and compliant wall properties. Main observations of present communication have been included in the conclusion section. PMID:27304458
Hayat, Tasawar; Nawaz, Sadaf; Alsaedi, Ahmed; Rafiq, Maimona
2016-01-01
Main objective of present study is to analyze the mixed convective peristaltic transport of water based nanofluids using five different nanoparticles i.e. (Al2O3, CuO, Cu, Ag and TiO2). Two thermal conductivity models namely the Maxwell's and Hamilton-Crosser's are used in this study. Hall and Joule heating effects are also given consideration. Convection boundary conditions are employed. Furthermore, viscous dissipation and heat generation/absorption are used to model the energy equation. Problem is simplified by employing lubrication approach. System of equations are solved numerically. Influence of pertinent parameters on the velocity and temperature are discussed. Also the heat transfer rate at the wall is observed for considered five nanofluids using the two phase models via graphs. PMID:27104596
This paper is devoted to the magnetohydrodynamic (MHD) peristaltic transport of nanofluid in a channel with wall properties. Flow analysis is addressed in the presence of viscous dissipation, partial slip and Joule heating effects. Mathematical modelling also includes the salient features of Brownian motion and thermophoresis. Both analytic and numerical solutions are provided. Comparison between the solutions is shown in a very good agreement. Attention is focused to the Brownian motion parameter, thermophoresis parameter, Hartman number, Eckert number and Prandtl number. Influences of various parameters on skin friction coefficient, Nusselt and Sherwood numbers are also investigated. It is found that both the temperature and nanoparticles concentration are increasing functions of Brownian motion and thermophoresis parameters. - Highlights: • Temperature rises when Brownian motion and thermophoresis effects intensify. • Temperature profile increases when thermal slip parameter increases. • Concentration field is a decreasing function of concentration slip parameter. • Temperature decreases whereas concentration increases for Hartman number
Peristaltic Pumping near Post-CME Supra-Arcade Current Sheets
Scott, Roger B; McKenzie, David E
2013-01-01
Measurements of temperature and density near supra-arcade current sheets suggest that plasma on unreconnected field lines may experience some degree of "pre-heating" and "pre-densification" prior to their reconnection. Models of patchy reconnection allow for heating and acceleration of plasma along reconnected field lines but do not offer a mechanism for transport of thermal energy across field lines. Here we present a model in which a reconnected flux tube retracts, deforming the surrounding layer of unreconnected field. The deformation creates constrictions that act as peristaltic pumps, driving plasma flow along affected field lines. Under certain circumstances these flows lead to shocks that can extend far out into the unreconnected field, altering the plasma properties in the affected region. These findings have direct implications for observations in the solar corona, particularly in regard to such phenomena as high temperatures near current sheets in eruptive solar flares and wakes seen in the form of ...
A Peristaltic Micro Pump Driven by a Rotating Motor with Magnetically Attracted Steel Balls
Zhaoying Zhou
2009-04-01
Full Text Available In this paper, we present a membrane peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls for lab-on-a-chip applications. The fabrication process is based on standard soft lithography technology and bonding of a PDMS layer with a PMMA substrate. A linear flow rate range ~490 μL/min was obtained by simply varying the rotation speed of a DC motor, and a maximum back pressure of 592 Pa was achieved at a rotation speed of 43 rpm. The flow rate of the pump can also be adjusted by using steel balls with different diameters or changing the number of balls. Nevertheless, the micro pump can also work in high speed mode. A high back pressure up to 10 kPa was achieved at 500 rpm using a high speed DC motor, and an utmost flow rate up to 5 mL/min was reached.
Sosnowchik, Brian D.; Galambos, Paul C.; Sharp, Kendra V.; Jenkins, Mark W.; Horn, Mark W.; Hendrix, Jason R.
2004-01-01
This paper presents the dry actuation testing procedures and results for novel viscous drag micropumping systems. To overcome the limitations of previously developed mechanical pumps, we have developed pumps that are surface micromachined for efficient mass production which utilize viscous drag (dominant at low Reynolds numbers typical of microfluidics) to move fluid. The SUMMiT (www.sandia.gov/micromachine) fabricated pumps, presented first by Kilani et al., are being experimentally and computationally analyzed. In this paper we will describe the development of optimal waveforms to drive the electrostatic pumping mechanism while dry. While wet actuation will be significantly different, dry testing provides insight into how to optimally move the mechanism and differences between dry and wet actuation can be used to isolate fluid effects. Characterization began with an analysis of the driving voltage waveforms for the torsional ratcheting actuator (TRA), a micro-motor that drove the gear transmission for the pump, actuated with SAMA (Sandia"s Arbitrary waveform MEMS Actuator), a new waveform generating computer program with the ability to generate and output arbitrary voltage signals. Based upon previous research, a 50% duty cycle half-sine wave was initially selected for actuation of the TRA. However, due to the geometry of the half-sine waveform, the loaded micromotor could not transmit the motion required to pump the tested liquids. Six waveforms were then conceived, constructed, and selected for device actuation testing. Dry actuation tests included high voltage, low voltage, high frequency, and endurance/reliability testing of the TRA, gear transmission and pump assembly. In the SUMMiT process, all of the components of the system are fabricated together on one silicon chip already assembled in a monolithic microfabrication process. A 40% duty cycle quarter-sine waveform with a 20% DC at 60V has currently proved to be the most reliable, allowing for an 825Hz
微量注射泵的质量检测及误差探究%Quality Inspection and Error Inquiry of the Injection Micro-pump
杨康为; 胡世辉; 龚婷婷
2016-01-01
通过对不同型号的微量注射泵进行质量控制检测，研究它们的瞬时流速、平均流速的相对误差和绝对误差，以期为日后质量控制工作的开展提供些许帮助，为临床在注射泵上的使用提供安全保障。%The research explores the relative and absolute error under the instantaneous velocity and the average velocity based on the quality control testing of different models of injection micro-pump. The research aims to help with the process of quality control of the injection micro-pump so as to enhance the reliability of the injection micro-pump in clinical practice.
微量注射泵的质量检测及误差探究%Quality Inspection and Error Inquiry of the Injection Micro-pump
杨康为; 胡世辉; 龚婷婷
2016-01-01
The research explores the relative and absolute error under the instantaneous velocity and the average velocity based on the quality control testing of different models of injection micro-pump. The research aims to help with the process of quality control of the injection micro-pump so as to enhance the reliability of the injection micro-pump in clinical practice.%通过对不同型号的微量注射泵进行质量控制检测，研究它们的瞬时流速、平均流速的相对误差和绝对误差，以期为日后质量控制工作的开展提供些许帮助，为临床在注射泵上的使用提供安全保障。
Multi-Phase Flow and Heat Transfer of a Micro-Pump Thermally Driven by a Multi-Output Pulse Laser
HUAI Xiu-Lan; TANG Zhi-Wei; WANG Guo-Xiang; WANG Wei-Wei
2005-01-01
@@ We present an experimental study of multi-phase flow and heat transfer in a micro-tube induced by a multi-output pulse laser. Extensive flow and heat transfer measurements and visualization experiments have been carried out to characterize the micro-pump behaviour under various conditions. The experiments reveal extremely unsteady and complex flow patterns in the micro tube with the flow closely related with generation and collapse of bubbles.It is found that the flow rates are controlled by the heating and condensation conditions within the tube. The laser pulse duration, pulse interval and output-power as well as the tube diameter all show a strong influence on the flow rate of the micro-pump. This study provides a basis for the design of thermally-driven micro-pump induced by a pulsed laser beam.
A new working principle for ac electro-hydrodynamic on-chip micro-pumps
Our new type of on-chip micro-pump exploits the ac electro-kinetic forces acting in the volume of a fluid in the presence of a temperature gradient. No mechanically movable parts are used. The velocity of the pump flow observed depends on the frequency and strength of the driving ac field and on the temperature gradient across the pump channel. An integrated heating element allows the temperature gradient to be adjusted. Both ac field electrodes and heating element are platinum structures processed on a glass chip. The pump-channel walls and cover are made from polymer and thin-glass, respectively. In this paper, we present measurements of the fluid velocity as functions of the medium conductivity (0.1-1.3 S m-1) and field frequency (300 kHz-52 MHz), voltage across the field-electrode voltage (0-35 Vrms) and the heating element (1.1-3.6 V). Velocities of up to 120 μm s-1 were observed in the pump channel. The advantage of our new design is an evenly shaped cross-section of the pump channel, which reduces the risk of the channel becoming clogged by debris. Ac-electro-osmosis is not a predominant effect in our structures. Pumping could only be observed when the heating current and ac-pump field were applied simultaneously. The effects observed were simulated with the COMSOL Multiphysics program
Development and Application of a Diaphragm Micro-Pump with Piezoelectric Device
Ma, H K; Wu, H Y; Lin, C Y; Gao, J J; Kou, M C
2008-01-01
In this study, a new type of thin, compact, and light weighed diaphragm micro-pump has been successfully developed to actuate the liquid by the vibration of a diaphragm. The micro-diaphragm pump with two valves is fabricated in an aluminum case by using highly accurate CNC machine, and the cross-section dimension is 5mm x 8mm. Both valves and diaphragm are manufactured from PDMS. The amplitude of vibration by a piezoelectric device produces an oscillating flow which may change the chamber volume by changing the curvature of a diaphragm. Several experimental set-ups for performance test in a single micro-diaphragm pump, isothermal flow open system, and a closed liquid cooling system is designed and implemented. The performance of one-side actuating micro-diaphragm pump is affected by the design of check valves, diaphragm, piezoelectric device, chamber volume, input voltage and frequency. The measured maximum flow rate of present design is 72 ml/min at zero total pump head in the range of operation frequency 70...
The Structure of Wheel Check Valve Influence on Air Block Phenomenon of Piezoelectric Micro-Pump
Song Chen
2015-11-01
Full Text Available To improve the stability and reliability of the piezoelectric micro-pump, the cause of air block phenomenon is analyzed on the structure of wheel check valve. During the movement of the bubble in the micro-channel, pressure drop occurs, the main factor which influences the bubble going through is opening height of the wheel check valve. Five groups of wheel check valves with different structures are used to test the wheel check valve opening height and air block probability. The experiment results show that reducing the wheel check valve thickness or diameter ratio can both increase the wheel check valve opening height, and decrease the air block probability. Through experiment, the optimum combination of the wheel check valve structure is obtained within the samples: as the thickness is 0.02 mm, the diameter ratio is 1.2, the wheel check valve opening height gets 252 µm, and within the given bubble volume, the air block probability is less than 2%.
A MEMS-based silicon micropump with intersecting channels and integrated hotwires
This paper presents the development of a gas-jet micropump with different cross-junctions and integrated hotwire. The device is actuated by a piezoelectric lead zirconate titanate (PZT) diaphragm at its resonant frequency. The design focuses on a cross-junction formed by the intersection of the channels and neck of the pump chamber, which allows differences in fluidic resistance and fluidic momentum during each PZT diaphragm vibration cycle and thus enables rectification of the gas without valves. Three different designs were investigated by utilizing the ANSYS-FLUENT software. Simulations and experimental data revealed that the step nozzle structure with anti-choking space has much more advantages than the others. The device has been fabricated by the standard MEMS process, and the tiny hotwire has been realized together with the fluidic network. Experiments have been carried out. At a driven frequency of 7.9 kHz, a flow rate of 5.2 ml min−1 was obtained with an applied sinusoidal voltage of 50 Vp-p. The output voltage on the hotwire was measured to be 130 mV at a constant current of I = 0.1 mA
A MEMS-based silicon micropump with intersecting channels and integrated hotwires
Thanh Dau, Van; Dinh, Thien Xuan; Sugiyama, Susumu
2009-12-01
This paper presents the development of a gas-jet micropump with different cross-junctions and integrated hotwire. The device is actuated by a piezoelectric lead zirconate titanate (PZT) diaphragm at its resonant frequency. The design focuses on a cross-junction formed by the intersection of the channels and neck of the pump chamber, which allows differences in fluidic resistance and fluidic momentum during each PZT diaphragm vibration cycle and thus enables rectification of the gas without valves. Three different designs were investigated by utilizing the ANSYS-FLUENT software. Simulations and experimental data revealed that the step nozzle structure with anti-choking space has much more advantages than the others. The device has been fabricated by the standard MEMS process, and the tiny hotwire has been realized together with the fluidic network. Experiments have been carried out. At a driven frequency of 7.9 kHz, a flow rate of 5.2 ml min-1 was obtained with an applied sinusoidal voltage of 50 Vp-p. The output voltage on the hotwire was measured to be 130 mV at a constant current of I = 0.1 mA.
PV-Li-ion-micropump membrane systems for portable personal desalination
Mark P. McHenry
2016-03-01
Full Text Available This research presents a technical simulation of theoretically portable desalination systems utilising low-energy and lightweight components that are either commercially available or currently in development. The commercially available components are small-scale flexible and portable photovoltaic (PV modules, Li-ion battery-converter units, and high pressure low voltage brushless DC motor-powered micropumps. The theoretical and conventional small-scale desalination membranes are compared against each other: low-pressure reverse osmosis (RO, nanofilters, graphene, graphene oxide, and graphyne technology. The systems were designed with the identical PV-Li-ion specifications and simulation data to quantify the energy available to power the theoretical energy demand for desalinating a saline water at 30,000–40,000 ppm total dissolved solid (TDS to reliably supply the minimum target of 3.5 L d−1 of freshwater for one theoretical year. The results demonstrate that modern portable commercially available PV-battery systems and new generations of energy-efficient membranes under development have the potential to enable users to sustainably procure daily drinking water needs from saline/contaminated water resources, with the system exhibiting a net reduction in weight than carrying water itself.
Dimitry Dumont-Fillon
2014-11-01
Full Text Available Improved glycemic control with insulin pump therapy in patients with type 1 diabetes mellitus has shown gradual reductions in nephropathy and retinopathy. More recently, the emerging concept of the artificial pancreas, comprising an insulin pump coupled to a continuous glucose meter and a control algorithm, would become the next major breakthrough in diabetes care. The patient safety and the efficiency of the therapy are directly derived from the delivery accuracy of rapid-acting insulin. For this purpose, a specific precision-oriented design of micropump has been built. The device, made of a stack of three silicon wafers, comprises two check valves and a pumping membrane that is actuated against stop limiters by a piezo actuator. Two membranes comprising piezoresistive strain gauges have been implemented to measure the pressure in the pumping chamber and at the outlet of the pump. Their high sensitivity makes possible the monitoring of the pumping accuracy with a tolerance of ±5% for each individual stroke of 200 nL. The capability of these sensors to monitor priming, reservoir overpressure, reservoir emptying, outlet occlusion and valve leakage has also been studied.
The possibility to generate a gas flow inside a channel just by imposing a tangential temperature gradient along the walls without the existence of an initial pressure difference is well known. The gas must be under rarefied conditions, meaning that the system must operate between the slip and the free molecular flow regimes, either at low pressure or/and at micro/nano-scale dimensions. This phenomenon is at the basis of the operation principle of Knudsen pumps, which are actually compressors without any moving parts. Nowadays, gas flows in the slip flow regime through microchannels can be modeled using commercial Computational Fluid Dynamics softwares, because in this regime the compressible Navier-Stokes equations with appropriate boundary conditions are still valid. A simulation procedure has been developed for the modeling of thermal creep flow using ANSYS Fluent®. The implementation of the boundary conditions is achieved by developing User Defined Functions (UDFs) by means of C++ routines. The complete first order velocity slip boundary condition, including the thermal creep effects due to the axial temperature gradient and the effect of the wall curvature, and the temperature jump boundary condition are applied. The developed simulation tool is used for the preliminary design of Knudsen micropumps consisting of a sequence of curved and straight channels.
Sheybani, Roya; Cobo, Angelica; Meng, Ellis
2015-08-01
We present a fully integrated implantable electrolysis-based micropump with incorporated EI dosing sensors. Wireless powering and data telemetry (through amplitude and frequency modulation) were utilized to achieve variable flow control and a bi-directional data link with the sensors. Wireless infusion rate control (0.14-1.04 μL/min) and dose sensing (bolus resolution of 0.55-2 μL) were each calibrated separately with the final circuit architecture and then simultaneous wireless flow control and dose sensing were demonstrated. Recombination detection using the dosing system, as well as, effects of coil separation distance and misalignment in wireless power and data transfer were studied. A custom-made normally closed spring-loaded ball check valve was designed and incorporated at the reservoir outlet to prevent backflow of fluids as a result of the reverse pressure gradient caused by recombination of electrolysis gases. Successful delivery, infusion rate control, and dose sensing were achieved in simulated brain tissue. PMID:26149696
A novel peristaltic pump for portable microfluidic devices has been recently designed and fabricated. The operation principle is based on the peristaltic motion of eight elastic pumping channels that are occluded by a screw shaft. The screw shaft rotating inside the pumping channel unit has a spirally arranged projection which deforms and closes down the channels as a normally closed valve. While the shaft rotates, the pinched locations in the channels move either way according to the direction of rotation, squeezing out the fluid inside. It features unlimited and quantitative fluid feeding with a wide range of flow rates for one channel from 3.5 µL min−1 at 3 rpm to 280.2 µL min−1 at 180 rpm. It was demonstrated that pulsation can be drastically reduced by merging two anti-phase channels.
In this study the peristaltic motion of Oldroyd fluid in an asymmetric channel is investigated. Mathematical analysis has been carried out in the presence of an inclined magnetic field. Heat transfer is also taken into account. The physical problem is first modeled and then the analytical solutions of coupled equations are developed by regular perturbation method. Assumptions of long wavelength approximation are used. Effects of inclined magnetic field on the axial velocity and temperature are presented. Physical features of pertinent parameters such as wave number δ, Reynolds number Re, Weissenberg number Wi, Prandtl number Pr and Hartmann number M are also discussed graphically at the end of the paper. - Highlights: • This paper analyses heat transfer and inclined magnetic effects in peristaltic motion of Oldroyd fluid. • An asymmetric channel under long wavelength approximation is considered. • Regular perturbation method is used to find analytical solutions. • Effects of sundry parameters are presented through graphs
In the current study, sway of nanofluid on peristaltic transport of a hyperbolic tangent fluid model in the incidence of tending magnetic field has been argued. The governing equations of a nanofluid are first modeled and then simplified under lubrication approach. The coupled nonlinear equations of temperature and nano particle volume fraction are solved analytically using a homotopy perturbation technique. The analytical solution of the stream function and pressure gradient are carried out using perturbation technique. The graphical results of the problem under discussion are also being brought under consideration to see the behavior of various physical parameters. - Highlights: • The main motivation of this work is that we want to see the behavior of nanofluids in peristaltic flows. • In literature few articles are available on this, but no article is available in asymmetric channel on the new fluid model hyperbolic tangent fluid. • So we want to fill the gap in literature studying this
In the present study, we discuss the peristaltic flow of a Johnson—Segalman fluid in an endoscope. Perturbation, homotopy, and numerical solutions are found for the non-linear differential equation. The comparative study is also made to check the validity of the solutions. The expressions for pressure rise frictional forces, pressure gradient, and stream lines are presented to interpret the behavior of various physical quantities of the Johnson—Segalman fluid. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Misra, J. C.; Maiti, S.; Shit, G. C.
2010-01-01
The paper deals with a theoretical investigation of the peristaltic transport of a physiological fluid in a porous asymmetric channel under the action of a magnetic field. The stream function, pressure gradient and axial velocity are studied by using appropriate analytical and numerical techniques. Effects of different physical parameters such as permeability, phase difference, wave amplitude and magnetic parameter on the velocity, pumping characteristics, streamline pattern and trapping are ...
A. V. Ramana Kumari; G. Radhakrishnamacharya
2011-01-01
The effects of slip and elasticity of flexible walls on peristaltic transport of an incompressible viscous fluid in a two dimensional uniform channel, with heat transfer in the presence of magnetic field is investigated. Using long wavelength approximation, a perturbation solution has been obtained in terms of wall slope parameter and closed form expressions are derived for average velocity, temperature and heat transfer. The effects of various pertinent parameters on average velocity and hea...
T Hayat; Maryam Iqbal; Humaira Yasmin; Fuad E Alsaadi; Huijun Gao
2015-07-01
A mathematical model is developed to analyse the peristaltic flow of couple-stress fluid in an inclined asymmetric channel with convective conditions. Soret and Dufour and Hall effects are taken into account. Analysis has been carried out in a wave frame of reference. Expressions for velocity, pressure gradient, temperature and concentration are constructed. Pumping and trapping phenomena are examined. Impact of sundry parameters on the velocity, temperature and concentration is discussed.
Tripathi, Dharmendra; Anwar Bég, O
2013-11-01
Magnetic fields are increasingly being utilized in endoscopy and gastric transport control. In this regard, the present study investigates the influence of a transverse magnetic field in the transient peristaltic rheological transport. An electrically-conducting couple stress non-Newtonian model is employed to accurately simulate physiological fluids in peristaltic flow through a sinusoidally contracting channel of finite length. This model is designed for computing the intra-bolus oesophageal and intestinal pressures during the movement of food bolus in the digestive system under magneto-hydro-dynamic effects. Long wavelength and low Reynolds number approximations have been employed to reduce the governing equations from nonlinear to linear form, this being a valid approach for creeping flows which characterizes physiological dynamics. Analytical approximate solutions for axial velocity, transverse velocity, pressure gradient, local wall shear stress and volumetric flow rate are obtained for the non-dimensional conservation equations subject to appropriate boundary conditions. The effects of couple stress parameter and transverse magnetic field on the velocity profile, pressure distribution, local wall shear stress and the averaged flow rate are discussed with the aid of computational results. The comparative study of non-integral and integral number of waves propagating along the finite length channel is also presented. Magnetic field and non-Newtonian properties are found to strongly influence peristaltic transport. PMID:23911695
The influence of an endoscope on peristaltic flow of a Jeffrey fluid through the cylindrical cavity between concentric tubes with variable magnetic field has been investigated. The governing equations of two dimensional fluid have been simplified under the consideration of long wavelength and low Reynolds number approximation. Exact analytical calculations are carried out for the pressure gradient, velocity, pressure rise, friction force on the inner and outer tubes and shear stress. The effect of the non-dimensional wave amplitude, the variable magnetic field, the ratio of relaxation of retardation time, the radius ratio and the non-dimensional volume flow are analyzed theoretically and computed numerically. Comparison was made with the results obtained in the presence and absence of variable magnetic field and an endoscope. The results indicate that the effect of the non-dimensional wave amplitude, variable magnetic field, ratio of relaxation to retardation time, radius ratio and non-dimensional volume flow on peristaltic flow are very pronounced. - Highlights: • The peristaltic flow of a Jeffrey fluid through the cylindrical cavity between concentric tubes with variable magnetic field. • Mathematical modeling is carried out by utilizing long wavelength and low Reynolds number assumptions. • Closed form expressions for the entered parameters have been computed numerically
ZnO film based surface acoustic wave micro-pump
In this study, a micro-pump unit based on surface acoustic wave (SAW) on piezoelectric ZnO film is designed and fabricated as a micro-fluidic device. It employs a mechanical wave, which is generated electrically using an aluminum interdigital transducer (IDT), and propagates on the surface of the ZnO film. The ZnO film was used in this study because it has a high electromechanical coefficient and an excellent bonding with various substrate materials, in particular silicon. The sputtering parameters for ZnO film deposition have been optimized, and the ZnO films with different thickness from 1 micron to 5.5 microns were prepared. The film properties have been characterized using different methods, such as scanning electron microscopy, X-ray diffraction and atomic force microscopy. Aluminum IDT with a finger width and spacing of 8 microns was patterned on the ZnO film using a lift-off process. The frequency generated was measured using a network analyzer, and it varies from 130 MHz to 180 MHz as a function of film thickness. A signal generator was used to generate the frequency with a power amplifier to amplify the signal, which was then applied to aluminum IDT to generate the surface acoustic wave. If a liquid droplet exists on the surface carrying the acoustic wave, the energy and the momentum of the SAW will be coupled into the fluid, causing the liquid to vibrate and move on film surface. The strength of this movement is determined by the applied voltage and frequency. The volume of the liquid drop loaded on the SAW device in this study is of several hundreds of nanoliters. The movement of the liquid inside the droplet and also on the ZnO film surface can be demonstrated. The performance of ZnO SAW device was characterized as a function of film thickness
Studies on spectroscopy of glycerol in THz range using microfluidic chip-integrated micropump
Su, Bo; Han, Xue; Wu, Ying; Zhang, Cunlin
2014-11-01
Terahertz time-domain spectroscopy (THz-TDS) is a detection method of biological molecules with label-free, non-ionizing, non-intrusive, no pollution and real-time monitoring. But owing to the strong THz absorption by water, it is mainly used in the solid state detection of biological molecules. In this paper, we present a microfluidic chip technique for detecting biological liquid samples using the transmission type of THz-TDS system. The microfluidic channel of the microfluidic chip is fabricated in the quartz glass using Micro-Electro-Mechanical System (MEMS) technology and sealed with polydimethylsiloxane (PDMS) diaphragm. The length, width and depth of the microfluidic channel are 25mm, 100μm and 50μm, respectively. The diameter of THz detection zone in the microfluidic channel is 4mm. The thicknesses of quartz glass and PDMS diaphragm are 1mm and 250μm, individually. Another one of the same quartz glass is used to bond with the PDMS for the rigidity and air tightness of the microfluidic chip. In order to realize the automation of sampling and improve the control precise of fluid, a micropump, which comprises PDMS diaphragm, pump chamber, diffuser and nozzle and flat vibration motor, is integrated on the microfluidic chip. The diffuser and nozzle are fabricated on both sides of the pump chamber, which is covered with PDMS diaphragm. The flat vibration motor is stuck on the PDMS diaphragm as the actuator. We study the terahertz absorption spectroscopy characteristics of glycerol with the concentration of 98% in the microfluidic chip by the aid of the THz-TDS system, and the feasibility of the microfluidic chip for the detection of liquid samples is proved.
Development and experimental testing of a peristaltic device actuated by a single shape-memory NiTi wire are described. The actuator is designed to radially shrink a compliant silicone pipe, and must work on a sustained basis at an actuation frequency that is higher than those typical of NiTi actuators. Four rigid, aluminum-made circular sectors are sitting along the pipe circumference and provide the required NiTi wire housing. The aluminum assembly acts as geometrical amplifier of the wire contraction and as heat sink required to dissipate the thermal energy of the wire during the cooling phase. We present and discuss the full experimental investigation of the actuator performance, measured in terms of its ability to reduce the pipe diameter, at a sustained frequency of 1.5 Hz. Moreover, we investigate how the diameter contraction is affected by various design parameters as well as actuation frequencies up to 4 Hz. We manage to make the NiTi wire work at 3% in strain, cyclically providing the designed pipe wall displacement. The actuator performance is found to decay approximately linearly with actuation frequencies up to 4 Hz. Also, the interface between the wire and the aluminum parts is found to be essential in defining the functional performance of the actuator. (paper)
Motion generation of peristaltic mobile robot with particle swarm optimization algorithm
Homma, Takahiro; Kamamichi, Norihiro
2015-03-01
In developments of robots, bio-mimetics is attracting attention, which is a technology for the design of the structure and function inspired from biological system. There are a lot of examples of bio-mimetics in robotics such as legged robots, flapping robots, insect-type robots, fish-type robots. In this study, we focus on the motion of earthworm and aim to develop a peristaltic mobile robot. The earthworm is a slender animal moving in soil. It has a segmented body, and each segment can be shorted and lengthened by muscular actions. It can move forward by traveling expanding motions of each segment backward. By mimicking the structure and motion of the earthworm, we can construct a robot with high locomotive performance against an irregular ground or a narrow space. In this paper, to investigate the motion analytically, a dynamical model is introduced, which consist of a series-connected multi-mass model. Simple periodic patterns which mimic the motions of earthworms are applied in an open-loop fashion, and the moving patterns are verified through numerical simulations. Furthermore, to generate efficient motion of the robot, a particle swarm optimization algorithm, one of the meta-heuristic optimization, is applied. The optimized results are investigated by comparing to simple periodic patterns.
Yo Tanaka
2014-05-01
Full Text Available Lab-on-a-chip technology is promising for the miniaturization of chemistry, biochemistry, and/or biology researchers looking to exploit the advantages of a microspace. To manipulate fluid on a microchip, on-chip pumps are indispensable. To date, there have been several types of on-chip pumps including pneumatic, electroactive, and magnetically driven. However these pumps introduce polymers, metals, and/or silicon to the microchip, and these materials have several disadvantages, including chemical or physical instability, or an inherent optical detection limit. To overcome/avoid these issues, glass has been one of the most commonly utilized materials for the production of multi-purpose integrated chemical systems. However, glass is very rigid, and it is difficult to incorporate pumps onto glass microchips. This paper reports the use of a very flexible, ultra-thin glass sheet (minimum thickness of a few micrometers to realize a pump installed on an entirely glass-based microchip. The pump is a peristaltic-type, composed of four serial valves sealing a cavity with two penetrate holes using ultra-thin glass sheet. By this pump, an on-chip circulating flow was demonstrated by directly observing fluid flow, visualized via polystyrene tracking particles. The flow rate was proportional to the pumping frequency, with a maximum flow rate of approximately 0.80 μL/min. This on-chip pump could likely be utilized in a wide range of applications which require the stability of a glass microchip.
Hall and ion slip effects on peristaltic flow and heat transfer analysis with Ohmic heating
S ASGHAR; Q HUSSAIN; T HAYAT; F ALSAADI
2014-01-01
The peristaltic transport of a magnetohydrodynamic (MHD) fluid is exam-ined for both symmetric and asymmetric channels. Hall and ion slip effects are taken into account. The heat transfer is analyzed by considering the effects of viscous and Ohmic dissipations. The relevant flow problems are first modeled, and then the closed form solutions are constructed under the assumptions of long wavelength and low Reynolds number. The solutions are analyzed through graphical illustration. It is noted that the velocity increases but the temperature decreases with the increases in the Hall and ion slip parameters. The axial pressure gradient is less in magnitude in the presence of Hall and ion slip currents. The Hall and ion slip effects are to decrease the maximum pres-sure against which peristalsis works as a pump. The free pumping flux decreases with the increases in the Hall and ion slip parameters. The increases in the Hall and ion slip parameters result in an increase in the size of the trapped bolus.
Pandey, S. K.; Chaube, M. K.
2011-09-01
This paper presents an analytical study of the MHD flow of a micropolar fluid through a porous medium induced by sinusoidal peristaltic waves traveling down the channel walls. Low Reynolds number and long wavelength approximations are applied to solve the non-linear problem in the closed form and expressions for axial velocity, pressure rise per wavelength, mechanical efficiency and stream function are obtained. The impacts of pertinent parameters on the aforementioned quantities are examined by plotting graphs on the basis of computational results. It is found that the pumping improves with Hartman number but degrades with permeability of the porous medium.
Fahad Abbasi
2016-01-01
Full Text Available This article addresses the peristaltic transport of Eyring-Prandtl fluid in an inclined asymmetric channel. Heat and mass transfer phenomena along with Soret and Dufour effects is analyzed. Effects of inclined magnetic field and Joule heating are also discussed. Long wavelength approximation is adopted. Numerical computations for flow quantities of interest are analyzed. It is found that the parabolic velocity profile tends to shift from center of the channel towards the channel walls in the case of opposing flow. Velocity and temperature decrease whereas concentration increases by increasing the non-Newtonian parameter. Further the dependence of magnetic field on the angle is quite significant
Safia AKRAM
2013-01-01
Full Text Available In this paper we have investigated the peristaltic flow of an incompressible six constant Jeffreys model of fluid in an asymmetric channel. The flow is investigated in a wave frame of reference moving with the velocity of the wave. We have modeled the governing equations of a two dimensional six constant Jeffreys model of fluid under long wave length and low Reynolds number approximation. The analytical and numerical solutions of the proposed problem are discussed. The expression for the pressure rise is calculated using numerical integration. The Graphical results are presented to interpret various physical parameters of interest.
Akbar, Noreen Sher; Raza, M; Ellahi, R
2016-07-01
The peristaltic flow of a copper oxide water fluid investigates the effects of heat generation and magnetic field in permeable tube is studied. The mathematical formulation is presented, the resulting equations are solved exactly. The obtained expressions for pressure gradient, pressure rise, temperature, velocity profile are described through graphs for various pertinent parameters. It is found that pressure gradient is reduce with enhancement of particle concentration and velocity profile is upturn, beside it is observed that temperature increases as more volume fraction of copper oxide. The streamlines are drawn for some physical quantities to discuss the trapping phenomenon. PMID:27208518
Misra, J C; Shit, G C; 10.1142/S0219519408002784
2010-01-01
The paper deals with a theoretical investigation of the peristaltic transport of a physiological fluid in a porous asymmetric channel under the action of a magnetic field. The stream function, pressure gradient and axial velocity are studied by using appropriate analytical and numerical techniques. Effects of different physical parameters such as permeability, phase difference, wave amplitude and magnetic parameter on the velocity, pumping characteristics, streamline pattern and trapping are investigated with particular emphasis. The computational results are presented in graphical form. The results are found to be in perfect agreement with those of a previous study carried out for a non-porous channel in the absence of a magnetic field.
F M Abbasi; A Alsaedi; T Hayat
2014-01-01
The present investigation addresses the simultaneous effects of heat and mass transfer in the mixed convection peristaltic flow of viscous fluid in an asymmetric channel. The channel walls exhibit the convective boundary conditions. In addition, the effects due to Soret and Dufour are taken into consideration. Resulting problems are solved for the series solutions. Numerical values of heat and mass transfer rates are displayed and studied. Results indicate that the concentration and temperature of the fluid increase whereas the mass transfer rate at the wall decreases with increase of the mass transfer Biot number. Furthermore, it is observed that the temperature decreases with the increase of the heat transfer Biot number.
Sheybani, Roya; Meng, Ellis
2014-01-01
Wireless infusion rate control and programmability for an implantable, low power, electrochemical micropump is presented. Flow rate control was achieved through adjustment of the wiper position of a current potentiometer in the wireless receiver (0.6-3.2 mA output current with a resolution of 0.2 mA per step). An off-the-shelf Bluetooth module and Basic Stamp microcontroller kit was used to initiate amplitude-shift keying (ASK) modulation of the inductive power signal. Accurate flow control of two model regimens was achieved on benchtop. Wireless transmission (power transfer and control) was not affected by simulated tissue material placed between the transmitter and receiver. PMID:25570100
Kothandapani, M., E-mail: mkothandapani@gmail.com [Department of Mathematics, University College of Engineering Arni, (A Constituent College of Anna University Chennai), Arni 632326, Tamil Nadu (India); Prakash, J., E-mail: prakashjayavel@yahoo.co.in [Department of Mathematics, Arulmigu Meenakshi Amman College of Engineering, Vadamavandal 604410, Tamil Nadu (India)
2015-03-15
Theoretical analyses on the effect of radiation and MHD on the peristaltic flow of a nanofluid through a porous medium in a two dimensional tapered asymmetric channel has been made. The nanofluid is assumed to be electrically conducting in the presence of a uniform magnetic field. The transport equation accounts the both Brownian motion and thermophoresis along with the radiation reaction. The problem has been further simplified with the authentic assumptions of long wavelength and small Reynolds number. The analytical expressions obtained for the axial velocity, stream function, temperature field, nanoparticle fraction field and pressure gradient provide satisfactory explanation. Influence of various parameters on the flow characteristics have been discussed with the help of graphical results. The trapping phenomenon has also been discussed in detail. - Highlights: • Combine effect of thermal radiation and MHD on the peristaltic flow of a Newtonian nanofluid are discussed. • This work may be first attempt dealing the study of Newtonian nanofluid flow in the porous tapered asymmetric channel. • The velocity, stream function, temperature field and nanoparticle fraction field provide satisfactory explanation with help of graphs.
Theoretical analyses on the effect of radiation and MHD on the peristaltic flow of a nanofluid through a porous medium in a two dimensional tapered asymmetric channel has been made. The nanofluid is assumed to be electrically conducting in the presence of a uniform magnetic field. The transport equation accounts the both Brownian motion and thermophoresis along with the radiation reaction. The problem has been further simplified with the authentic assumptions of long wavelength and small Reynolds number. The analytical expressions obtained for the axial velocity, stream function, temperature field, nanoparticle fraction field and pressure gradient provide satisfactory explanation. Influence of various parameters on the flow characteristics have been discussed with the help of graphical results. The trapping phenomenon has also been discussed in detail. - Highlights: • Combine effect of thermal radiation and MHD on the peristaltic flow of a Newtonian nanofluid are discussed. • This work may be first attempt dealing the study of Newtonian nanofluid flow in the porous tapered asymmetric channel. • The velocity, stream function, temperature field and nanoparticle fraction field provide satisfactory explanation with help of graphs
K. Ramesh; M. Devakar
2015-01-01
The intention of this investigation is to study the effects of heat transfer and inclined magnetic field on the peristaltic flow of Williamson fluid in an asymmetric channel through porous medium. The governing two-dimensional equations are simplified under the assumption of long wavelength approximation. The simplified equations are solved for the stream function, temperature, and axial pressure gradient by using a regular perturbation method. The expression for pressure rise is computed numerically. The profiles of velocity, pressure gradient, temperature, heat transfer coefficient and stream function are sketched and interpreted for various embedded parameters and also the behavior of stream function for various wave forms is discussed through graphs. It is observed that the peristaltic velocity increases from porous medium to non-porous medium, the magnetic effects have increasing effect on the temperature, and the size of the trapped bolus decreases with the increasing of magnetic effects while the trend is reversed with the increasing of Darcy number. Moreover, limiting solutions of our problem are in close agreement with the corresponding results of the Newtonian fluid model.
Swarnalathamma, B. V.; Krishna, M. Veera
2016-05-01
In this paper, we discussed the theoretical and computational study of peristaltic hemodynamic flow of couple stress fluids through a porous medium under the influence of magnetic field with wall slip condition. Actually this study is motivated towards the physiological flow of the blood in the micro circulatory system by taking account of the particle size effect. We consider the Reynolds number is small enough and the wave length to diameter ratio is large enough to negate inertial effects. The governing equations for the couple stress fluid flow through porous medium based on stoke constitutive equations and Brinkman model. The exact solutions for axial velocity, pressure gradient, frictional force, stream function and mechanical efficiency are obtained analytically, its behaviour computationally discussed with reference to different physical parameters reflecting couple stress parameter, Hartmann number, permeability parameter, slip parameter as well as amplitude ratio on pumping characteristics and frictional force, stream lines pattern and trapping of peristaltic flow pattern are studied with particular emphasis making use of graphs.
Objective: To directly compare CT enterography (CTE) and MR enterography (MRE) without antiperistaltic agents. Materials/methods: 26 patients referred for CTE underwent CTE immediately followed by MRE without use of an anti-peristaltic agent. Each study was evaluated on a 10 point scale for exam quality, level of diagnostic confidence, and presence of Crohn's disease. Kappa analysis was performed to determine the degree of agreement between the CTE and MRE of each patient. Results: 25 patients completed the MRE. The quality of the CTEs was judged as excellent by both readers (reader 1 = average 9.5/10, reader 2 = average 9.1/10). The quality of the MREs was ranked lower than the CTEs by both readers (reader 1 = average 8.9/10, reader 2 = average 7.2/10), which was statistically significant (p < 0.05). The level of confidence in interpretation was not significantly different between CTE and MRE for reader 1 or 2 (p = 0.3). There was substantial agreement between readers for the presence or absence of Crohn's disease on both CTE (kappa = 0.75) and MRE (kappa = 0.67). Conclusion: MR enterography without anti-peristaltic agents results in high diagnostic confidence and excellent agreement for the presence of Crohn's disease.
Graf, Neil J; Bowser, Michael T
2013-10-01
Two different fabrication methods were employed to fabricate micropumps with different cross-sectional channel geometries. The first was to fabricate rectangular cross-sectional microchannel geometries using the well known fabrication method of replica molding (REM). The second, and far less utilized fabrication technique, was to create microchannel molds using an in-house fabricated handheld micro injection molding apparatus. The injection mold apparatus was designed for use with elastomeric room temperature vulcanization (RTV) polymers, as opposed to most other injection molding machines, which are designed for use with thermoplastic polymers. The injection mold's bottom plate was used as a microchannel molding template. The molding template was created by threading a small-diameter wire (150 μm or less) through the injection mold's bottom plate, with subsequent adhesion and smoothing of a thin piece of aluminum foil over the wire-raised injection mold template. When molded against, the template produced a rounded/Gaussian-shaped PDMS microchannel. The design of the injection mold will be presented, along with a direct comparison for micropump performance metrics such as flow rate, valving characteristics, and maximum backpressures attainable for each of the respective micropump channel geometries. PMID:23917263
Kh. S. Mekheimer
2008-01-01
Full Text Available A serious pathological condition is encountered when some blood constituents deposited on the blood vessels get detached from the wall, join the blood stream again and form a clot. Study of the peristaltic transport of a micropolar fluid in an annular region is investigated under low Reynolds number and long wavelength approximations. We model a small artery as a tube having a sinusoidal wave travelling down its wall and a clot model inside it. Closed form solutions are obtained for the velocity and the microrotation components, as well as the stream function, and they contain new additional parameters, namely, δ, the height of the clot, N, the coupling number and m, the micropolar parameter. The pressure rise and friction force on the inner and the outer tubes have been discussed for various values of the physical parameters of interest.
Abbasi, F. M.; Hayat, T.; Alsaedi, A.
2015-05-01
Impact of applied magnetic field on the peristaltic transport of Carreau-Yasuda fluid in a curved conduit is analyzed in this article. Hall effects are also taken into consideration. Lubrication approach is utilized in problem formulation. Resulting nonlinear system is solved numerically. Results for axial velocity, pressure gradient, pressure rise per wavelength and stream function are obtained and studied graphically. Results revealed that for small values of curvature parameter the fluid velocity is not symmetric about the centerline. Also increase in the value of Hall parameter balances the magnetic influence of applied magnetic field by some extent. Further, the Carreau-Yasuda fluid possesses large size of trapped bolus when compared with the Newtonian fluid.
Abbasi, F.M., E-mail: abbasisarkar@gmail.com [Department of Mathematics, Comsats Institute of Information Technology, Islamabad 44000 (Pakistan); Hayat, T. [Department of Mathematics, Quaid-I-Azam University, 45320 Islamabad 44000 (Pakistan); Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alsaedi, A. [Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)
2015-05-15
Impact of applied magnetic field on the peristaltic transport of Carreau–Yasuda fluid in a curved conduit is analyzed in this article. Hall effects are also taken into consideration. Lubrication approach is utilized in problem formulation. Resulting nonlinear system is solved numerically. Results for axial velocity, pressure gradient, pressure rise per wavelength and stream function are obtained and studied graphically. Results revealed that for small values of curvature parameter the fluid velocity is not symmetric about the centerline. Also increase in the value of Hall parameter balances the magnetic influence of applied magnetic field by some extent. Further, the Carreau–Yasuda fluid possesses large size of trapped bolus when compared with the Newtonian fluid.
The effects of both magnetic field and wall slip conditions on the peristaltic transport of a Newtonian fluid in an asymmetric channel are studied analytically and numerically. The channel asymmetry is generated by propagation of waves on the channel walls travelling with different amplitudes, phases but with the same speed. The long wavelength and low Reynolds number assumptions are considered in obtaining solution for the flow. The flow is investigated in a wave frame of reference moving with velocity of the wave. Closed form expressions have been obtained for the stream function and the axial velocity component in fixed frame. The effects of phase difference, Knudsen number and magnetic field on the pumping characteristics and velocity field are discussed. Several known results of interest are found to follow as particular cases of the solution of the problem considered