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Sample records for cantilever-actuated peristaltic micropump

  1. Development of a high performance peristaltic micropump

    Science.gov (United States)

    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.

  2. Piezoelectric peristaltic micropump with a single actuator

    Science.gov (United States)

    Pečar, Borut; Križaj, Dejan; Vrtačnik, Danilo; Resnik, Drago; Dolžan, Tine; Možek, Matej

    2014-10-01

    A high performance piezoelectric PDMS peristaltic micropump with a single actuator is presented that enables driving with less expensive and simpler single-phase controllers while maintaining all the superior properties of conventional peristaltic micropumps, such as robustness, simplicity and purity due to the absence of valves. A simple structural design is based on a centrally placed inlet port which leads directly into the center of the pumping chamber. During excitation the loosely attached glass membrane and elastomer (PDMS) deform in a controlled manner, which enables compression and expansion of the central inlet port and the outlet fluidic channel with a phase lag that is typical for operation of peristaltic pumps. For proper micropump operation, the volume of the circular pumping chamber area should be much larger than the volume around the secondary deformation extremum that appears in the area of the outlet fluidic channel. To experimentally validate the principle of operation and evaluate the repeatability of the fabrication process, four monoactuator peristaltic (MAP) micropump prototypes were fabricated and characterized. Fabricated prototypes featured high water / air flowrate performance (up to 0.24 ml min-1/up to 0.84 ml min-1), back-pressure performance (up to 360 mbar/up to 80 mbar) and suction pressure performance (down to -165 mbar/down to -140 mbar). Furthermore, bubble tolerance and self-priming capability have been proved, together with valve regime of operation that enables sealing of the fluidic path when appropriate dc voltage is applied.

  3. Development and characterization of thermopneumatic peristaltic micropumps

    International Nuclear Information System (INIS)

    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

  4. Development and characterization of thermopneumatic peristaltic micropumps

    Science.gov (United States)

    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.

  5. A vacuum-driven peristaltic micropump with valved actuation chambers

    International Nuclear Information System (INIS)

    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

  6. A peristaltic micropump using traveling waves on a polymer membrane

    International Nuclear Information System (INIS)

    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)

  7. PDMS Based Thermopnuematic Peristaltic Micropump for Microfluidic Systems

    International Nuclear Information System (INIS)

    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

  8. Portable Valve-less Peristaltic Micro-pump Design and Fabrication

    CERN Document Server

    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.

  9. Development of a peristaltic gas micropump with a single chamber and multiple electrodes

    International Nuclear Information System (INIS)

    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)

  10. Development of a peristaltic micropump for bio-medical applications based on mini LIPCA

    OpenAIRE

    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...

  11. Portable Valve-less Peristaltic Micro-pump Design and Fabrication

    OpenAIRE

    H. Yang; Tsai, T. -H.; Hu, C.-C.

    2008-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838); International audience; 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 flo...

  12. Dynamic simulation of a peristaltic micropump considering coupled fluid flow and structural motion

    OpenAIRE

    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...

  13. Development of a Peristaltic Micropump for Bio-Medical Applications Based on Mini LIPCA

    Institute of Scientific and Technical Information of China (English)

    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.

  14. Development of a peristaltic micropump for bio-medical applications based on mini LIPCA

    CERN Document Server

    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.

  15. Design and dynamic characterization of "single-stroke" peristaltic PDMS micropumps.

    Science.gov (United States)

    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

  16. Effect of actuation sequence on flow rates of peristaltic micropumps with PZT actuators.

    Science.gov (United States)

    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

  17. Dynamic simulation of a peristaltic micropump considering coupled fluid flow and structural motion

    Science.gov (United States)

    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.

  18. 一种负压驱动的蠕动微型泵设计%Design of a Peristaltic Micropump Driven by Pneumatic Pressure

    Institute of Scientific and Technical Information of China (English)

    崔建国; 王洪

    2012-01-01

    微型泵作为集成微流体中不可或缺的元素,在过去20年间取得了很大的进展.基于真空负压驱动原理,研制了一种结构简单的蠕动式微型泵.微型泵由三层聚二甲基硅氧烷(PDMS)材料构成(气路层,流路层,驱动薄膜层),并通过表面等离子体氧化处理技术实现了PDMS层之间的键合封装,其全部结构均采用激光器加工制作而成.蠕动驱动模式的关键在于利用气路周期性地传递负压力波,进而实现弹性薄膜的顺序变形,其中负压源通过电磁阀(EMV)进行通断控制.这种结构简化了常规蠕动泵模型中的复杂逻辑控制.实验结果表明在50kPa负压和30Hz驱动频率的条件下,获得的最佳流速为170 μL/min.%As an indispensable element in integrated microfluidics, micropumps have gradually evolved over the past two decades. Based on vacuum-driven principle, a simple peristaltic micropump is developed. The micropump fabricated by laser mi-cromachining and plasma bonding of three polydimethylsiloxane (PDMS) layers, includes a pneumatic channel layer, actuation membrane layer, and microfluidic channel layer. As the key to peristaltic motion, the sequential deflection of the elastic membranes is achieved by periodic pressure waveforms ( negative) traveling through the pneumatic channel, provided by a vacuum source regulated by an electromagnetic valve ( EMV). This configuration eliminates the complicated control logic typically required in peristaltic motion. Experiment results show that a maximal flow rate of 170 μL min-1 has been optimized at the pulsed vacuum frequency of 30 Hz with a vacuum pressure of 50 kPa.

  19. 聚二甲基硅氧烷气动微型蠕动泵制作工艺的研究%Study on Process of Polydimethyl Siloxane Pneumatic Peristaltic Micropump

    Institute of Scientific and Technical Information of China (English)

    关艳霞; 王宏; 徐章润

    2009-01-01

    聚二甲基硅氧烷(PDMS)气动微型泵由3个PDMS气动微阀构成,依靠3个微阀的蠕动作用实现输运液体的作用.PDMS气动微泵的关键制作工艺是液体通道的弧形化和PDMS层之间、PDMS层与玻璃基片之间的封接.实验证明AZ4620正性光刻胶所制作的阳模能形成剖面形状呈弧形的液体通道.采用等离子体氧化处理法封接技术实现了PDMS层之间、PDMS层与玻璃基片之间的封接,该工艺易操作,封接速度快,而且封接效果好.%A polydimethyl siloxane (PDMS) pneumatic micropump is constituted of three active pneumatic micro-valves , and the transport of liquid is realized by Peristaltic working of three valves.Major factors in the fabrication of PDMS pneumatic micropumps are the formation of arc-shaped channel profiles of the liquid channel and bonding PDMS layers as well as bonding between the PDMS layer and the glass slide.AZ4620 positive photoresist was demonstrated the best performance as a positive master for producing a liquid channel with an ideal cross sectional profile.The bonding following plasma cleaning showed the best result was used as the bonding means for fabricating PDMS pneumatic micropumps.This process was demonstrated easy to operate,fast to bond.

  20. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Deformation Analysis of a Pneumatically-Activated Polydimethylsiloxane (PDMS) Membrane and Potential Micro-Pump Applications

    OpenAIRE

    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...

  2. Deformation Analysis of a Pneumatically-Activated Polydimethylsiloxane (PDMS Membrane and Potential Micro-Pump Applications

    Directory of Open Access Journals (Sweden)

    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.

  3. All Polymer Micropump

    OpenAIRE

    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...

  4. Magnetically actuated micropumps

    OpenAIRE

    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...

  5. Magnetically actuated micropumps

    OpenAIRE

    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...

  6. All Polymer Micropump

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen

    2008-01-01

    of the substrate, the PEDOT is integrated into the non-conductive polymer. The result is a material that retains the good conductivity of PEDOT, but gains the mechanical stability of the substrate. The best results were obtained for PEDOTjPMMA. The new mechanically stable PEDOTjPMMA was micro-patterned using clean...... (ACEO) micropump. The ACEO pump consists of an array of interdigitated small and large PEDOTjPMMA encapsulated in a polyurethane (PUR) channel system. The pumping velocity was detected using fluorescent microspheres and a confocal microscope. The pump characteristics resembled those of pumps based...

  7. Design of an implantable micropump

    OpenAIRE

    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...

  8. Multi-channel peristaltic pump for microfluidic applications featuring monolithic PDMS inlay

    DEFF Research Database (Denmark)

    Skafte-Pedersen, Peder; Sabourin, David; Dufva, Martin;

    2009-01-01

    The design, fabrication and characterization of a miniaturized, mechanically-actuated 12-channel peristaltic pump for microfluidic applications and built from simple, low-cost materials and fabrication methods is presented. Two pump configurations are tested, including one which reduces pulsating...... flow. Both use a monolithic PDMS pumping inlay featuring three-dimensional geometries favourable to pumping applications and 12 wholly integrated circular channels. Flow rates in the sub-µL min-1 to µL min-1 range were obtained. Channel-to-channel flow rate variability was comparable to a commercial...... pumping system at lower flow rates. The small footprint, 40 mm by 80 mm, of the micropump renders it portable, and allows its use on microscope stages adjacent to microfluidic devices, thus reducing system dead volumes. The micropump's design allows potential use in remote and resource-limited locations...

  9. Towards an Implantable, Low Flow Micropump That Uses No Power in the Blocked-Flow State

    Directory of Open Access Journals (Sweden)

    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.

  10. A Magnetic Micropump Based on Ferrofluidic Actuation

    Directory of Open Access Journals (Sweden)

    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.

  11. Experimental investigation on phase transformation type micropump

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The phase transformation type micropump without moving parts was experimentally studied in this note.To analyze the pumping mechanism of the micropump, a simplified physical model was presented. The experimental results indicate that the pump characteristic is mainly dependent on the heating and cooling conditions. For a given system, there exist an optimal combination of heating current and switch time with which the flow rate reaches maximum. Comparing with the natural cooling, the forced convective cooling needs larger heating current to obtain the same flow rate. In our experiments, the maximum flow rate is 33 μL/min when the inner diameter of the micropump is 200 μm, and the maximum pumping pressure reaches over 20 kPa. The theoretical analysis shows that the pumping mechanism of the micropump mainly lies in the large density difference between liquid and gas phases and the effect of gas chocking.

  12. Induction electrohydrodynamics micropump forhigh heat flux cooling

    OpenAIRE

    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...

  13. A Micropump Driven by Marangoni Effect

    Science.gov (United States)

    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.

  14. Multi-path peristaltic pump

    Science.gov (United States)

    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.

  15. Design,fabrication and experimental research for an electrohydrodynamic micropump

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Carbon Nanotube Amperometric Chips with Pneumatic Micropumps

    Science.gov (United States)

    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.

  17. Performance characteristics of valveless and cantilever-valve micropump

    Science.gov (United States)

    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.

  18. High precision innovative micropump for artificial pancreas

    Science.gov (United States)

    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.

  19. LIQUID-SOLID COUPLED SYSTEM OF MICROPUMP

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Modular Architecture of a Non-Contact Pinch Actuation Micropump

    OpenAIRE

    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...

  1. Surface micromachined electrostatically actuated micro peristaltic pump

    OpenAIRE

    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...

  2. Continuous dynamic flow micropumps for microfluid manipulation

    International Nuclear Information System (INIS)

    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)

  3. The dynamic characteristics of a valve-less micropump

    Institute of Scientific and Technical Information of China (English)

    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.

  4. A global assessment of piezoelectric actuated micro-pumps

    OpenAIRE

    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 ...

  5. Linear peristaltic pump based on electromagnetic actuators

    Directory of Open Access Journals (Sweden)

    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.

  6. Development and Application of One-Sided Piezoelectric Actuating Micropump

    Directory of Open Access Journals (Sweden)

    H. K. Ma

    2013-01-01

    Full Text Available Three types of one-sided actuating piezoelectric micropumps are studied in this paper. In the first type, one-sided actuating micropump with two check valves can enhance the flow rate and prevent the back flow in suction mode to keep the flow in one direction. Furthermore, the frequency modulator is applied in the micropump to adjust and promote the maximum flow rate higher than 5.0 mL/s. In the second type, valveless micropump with secondary chamber shows that the secondary chamber plays a key role in the application of the valveless micropump. It not only keeps the flow in one direction but also makes the flow rate of the pump reach 0.989 mL/s. In addition, when a nozzle/diffuser element is used in valveless micropump, the flow rate can be further improved to 1.183 mL/s at a frequency of 150 Hz. In the third type, piezoelectric actuating pump is regarded as an air pump in the application of a microfuel cell system, which can increase more air inlet to improve the fuel/air reaction and further increase the performance of fuel cell.

  7. Design and modeling of a light powered biomimicry micropump

    Science.gov (United States)

    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.

  8. Peristaltic pumps work in nano scales

    OpenAIRE

    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...

  9. Peristaltic Transport through Eccentric Cylinders: Mathematical Model

    Directory of Open Access Journals (Sweden)

    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.

  10. Piezoelectric diffuser/nozzle micropump with double pump chambers

    Institute of Scientific and Technical Information of China (English)

    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.

  11. Simulation of valveless micropump and mode analysis

    CERN Document Server

    Lan, W P; Wu, K C; Shih, Y C

    2008-01-01

    In this work, a 3-D simulation is performed to study for the solid-fluid coupling effect driven by piezoelectric materials and utilizes asymmetric obstacles to control the flow direction. The result of simulation is also verified. For a micropump, it is crucial to find the optimal working frequency which produce maximum net flow rate. The PZT plate vibrates under the first mode, which is symmetric. Adjusting the working frequency, the maximum flow rate can be obtained. For the micrpump we studied, the optimal working frequency is 3.2K Hz. At higher working frequency, say 20K Hz, the fluid-solid membrane may come out a intermediate mode, which is different from the first mode and the second mode. It is observed that the center of the mode drifts. Meanwhile, the result shows that a phase shift lagging when the excitation force exists in the vibration response. Finally, at even higher working frequency, say 30K Hz, a second vibration mode is observed.

  12. Analysis, design and experimental characterization of electrostatically actuated gas micropumps

    Science.gov (United States)

    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

  13. Valveless Thermally-Driven Phase-Change Micropump

    Institute of Scientific and Technical Information of China (English)

    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.

  14. A linear peristaltic MRF/foam actuator

    Science.gov (United States)

    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.

  15. Microbionic and peristaltic robots in a pipe

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A microbionic and peristaltic robot that simulates the motion of an earthworm to move within a micropipe is proposed. The robot consists of three flexible units. Each unit is composed of two plates connected with three shape memory alloys (SMA) 120°apart, the rubber gasbag around the SMA wires inflated with air inside. Each unit corresponds to a segment of an earthworm, and the SMA and rubber gasbag have the same functions as the cricoid and longitudinal muscles of the earthworm. A control system is designed to fulfill the control of the three flexible units motions, such as stretching, shrinking and bending, so the microrobot can walk forward and backward, and choose the direction.

  16. Modular Architecture of a Non-Contact Pinch Actuation Micropump

    Directory of Open Access Journals (Sweden)

    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.

  17. A high current density DC magnetohydrodynamic (MHD) micropump

    NARCIS (Netherlands)

    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

  18. A high current density DC magnetohydrodynamic (MHD) micropump

    NARCIS (Netherlands)

    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

  19. Swimming and peristaltic pumping between two plane parallel walls

    International Nuclear Information System (INIS)

    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.

  20. Optimization design of multi-material micropump using finite element method

    OpenAIRE

    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...

  1. Optofluidic modulator based on peristaltic nematogen microflows

    Science.gov (United States)

    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.

  2. Concepts for a new class of all-polymer micropumps.

    Science.gov (United States)

    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

  3. A novel reciprocating micropump based on Lorentz force

    Science.gov (United States)

    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.

  4. SU8 diaphragm micropump with monolithically integrated cantilever check valves.

    Science.gov (United States)

    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

  5. Postprandial transduodenal bolus transport is regulated by complex peristaltic sequence

    Institute of Scientific and Technical Information of China (English)

    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.

  6. Development of a solenoid actuated planar valveless micropump with single and multiple inlet–outlet arrangements

    Science.gov (United States)

    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.

  7. A polymer chip-integrable piezoelectric micropump with low backpressure dependence

    DEFF Research Database (Denmark)

    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 and tes...

  8. Heat Transfer Analysis for Peristaltic Mechanism in Variable Viscosity Fluid

    Institute of Scientific and Technical Information of China (English)

    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.

  9. A modeling and vibration analysis of a piezoelectric micro-pump diaphragm

    Science.gov (United States)

    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.

  10. Peristaltic pump-based low range pressure sensor calibration system

    Science.gov (United States)

    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.

  11. Peristaltic pump-based low range pressure sensor calibration system

    International Nuclear Information System (INIS)

    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

  12. Electroosmosis-modulated peristaltic transport in microfluidic channels

    Science.gov (United States)

    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.

  13. Peristaltic pump-based low range pressure sensor calibration system.

    Science.gov (United States)

    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

  14. Peristaltic pump-based low range pressure sensor calibration system

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Long Wavelength Peristaltic Transport of Non-Newton Fluids

    OpenAIRE

    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.

  16. Peristaltic pump-based low range pressure sensor calibration system.

    Science.gov (United States)

    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.

  17. A Numerical Investigation of Peristaltic Waves in Circular Tubes

    Science.gov (United States)

    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.

  18. DESIGN AND OPTIMIZATION OF VALVELESS MICROPUMPS BY USING GENETIC ALGORITHMS APPROACH

    Directory of Open Access Journals (Sweden)

    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.

  19. Pneumatically Actuated Miniature Peristaltic Vacuum Pumps

    Science.gov (United States)

    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

  20. Metal additive manufacturing of a high-pressure micro-pump

    OpenAIRE

    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...

  1. A dynamic model of valveless micropumps with a fluid damping effect

    International Nuclear Information System (INIS)

    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.

  2. A dynamic model of valveless micropumps with a fluid damping effect

    Science.gov (United States)

    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.

  3. Vibration analysis of magnetostrictive thin-film composite cantilever actuator

    Science.gov (United States)

    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.

  4. A dynamic model for studying valveless electromagnetic micropumps

    International Nuclear Information System (INIS)

    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.

  5. A dynamic model for studying valveless electromagnetic micropumps

    Science.gov (United States)

    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.

  6. Dual independent displacement-amplified micropumps with a single actuator

    Science.gov (United States)

    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.

  7. Flow behavior of liquid-solid coupled system of piezoelectric micropump

    Institute of Scientific and Technical Information of China (English)

    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.

  8. Peristaltic particle transport using the Lattice Boltzmann method

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Effects of Magnetic Field and an Endoscope on Peristaltic Motion

    Directory of Open Access Journals (Sweden)

    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.

  10. Performance of miniaturized direct methanol fuel cell (DMFC) devices using micropump for fuel delivery

    Science.gov (United States)

    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.

  11. Two way fluid structure interaction analysis of a valveless micropump by CFD

    Science.gov (United States)

    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.

  12. Performance of a serial-connection multi-chamber piezoelectric micropump

    Institute of Scientific and Technical Information of China (English)

    KAN Jun-wu; XUAN Ming; LIU Guo-jun; YANG Zhi-gang; WU Yi-hui

    2005-01-01

    The concept and structure of serial-connection multi-chamber (SCMC) micropumps with cantilever valves is introduced. The SCMC micropump, which can be manufactured using conventional production techniques and materials, has a multi-layer circular planar structure. The border-upon piezoelectric actuators of a SCMC micropump work in anti-phase, as a result the pumping performance is similar to that of several single-chamber pumps running in series. The theoretical analysis shows that the pumping performance of a SCMC micropump depends not only on the characteristic and geometrical parameters of the piezoelectric actuators, but also on the number of pump chambers. Both flowrate and pressure of a SCMC pump can be enhanced to a certain extent. Four piezoelectric micropumps with different chambers were fabricated and tested. The testing results show that the enhancing extents of the flowrate and pressure of a SCMC piezoelectric micropump are different. The maximum flowrate and pressure of the four-chamber pump achieved are 2.5 times and 3.6 times those of the single-chamber pump achieved.

  13. Modeling and design of light powered biomimicry micropump utilizing transporter proteins

    Science.gov (United States)

    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.

  14. Backward flow in a surface tension driven micropump

    International Nuclear Information System (INIS)

    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)

  15. Actuation method and apparatus, micropump, and PCR enhancement method

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Design, fabrication, and characterization of a valveless magnetic travelling-wave micropump

    International Nuclear Information System (INIS)

    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)

  17. An Electromagnetically-Actuated All-PDMS Valveless Micropump for Drug Delivery

    Directory of Open Access Journals (Sweden)

    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.

  18. Static characteristic analysis on a hydrodynamic bearing of a hydraulic suspended micropump

    International Nuclear Information System (INIS)

    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

  19. A membrane-based serpentine-shape pneumatic micropump with pumping performance modulated by fluidic resistance

    International Nuclear Information System (INIS)

    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

  20. Simulations of Micropumps Based on Tilted Flexible Fibers

    Science.gov (United States)

    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.

  1. Design, modeling and fabrication of a constant flow pneumatic micropump

    Science.gov (United States)

    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.

  2. Treating gastrointestinal cancer by intervention, intraperitoneal hyperthermic perfusion chemotherapy, intravenous micro-pump chemotherapy

    International Nuclear Information System (INIS)

    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)

  3. Design of IPMC actuator-driven valve-less micropump and its flow rate estimation at low Reynolds numbers

    Science.gov (United States)

    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.

  4. Streamline topologies and their bifurcations for mixed convective peristaltic flow

    Directory of Open Access Journals (Sweden)

    Z. Asghar

    2015-09-01

    Full Text Available In this work our focus is on streamlines patterns and their bifurcations for mixed convective peristaltic flow of Newtonian fluid with heat transfer. The flow is considered in a two dimensional symmetric channel and the governing equations are simplified under widely taken assumptions of large wavelength and low Reynolds number in a wave frame of reference. In order to study the streamlines patterns, a system of nonlinear autonomous differential equations are established and dynamical systems approach is used to discuss the local bifurcations and their topological changes. We have discussed all types of bifurcations and their topological changes are presented graphically. We found that the vortices contract along the vertical direction whereas they expand along horizontal direction. A global bifurcations diagram is used to summarize the bifurcations. The trapping and backward flow regions are mainly affected by increasing Grashof number and constant heat source parameter in such a way that trapping region increases whereas backward flow region shrinks.

  5. Peristaltic Transport of a Couple Stress Fluid : Some Physiological Applications

    CERN Document Server

    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...

  6. Development of Stepper motor based Two DOF Robotic Arm Transferring Liquid using Peristaltic Pump

    OpenAIRE

    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 ...

  7. Peristaltic Flow of Phan-Thien-Tanner Fluid in an Asymmetric Channel with Porous Medium

    OpenAIRE

    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...

  8. A self-priming, high performance, check valve diaphragm micropump made from SOI wafers

    Science.gov (United States)

    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.

  9. A self-priming, high performance, check valve diaphragm micropump made from SOI wafers

    International Nuclear Information System (INIS)

    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

  10. Characteristic of TiNi(Cu) shape memory thin film based on micropump

    Science.gov (United States)

    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.

  11. Metal additive manufacturing of a high-pressure micro-pump

    NARCIS (Netherlands)

    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

  12. Three dimensional transient multifield analysis of a piezoelectric micropump for drug delivery system for treatment of hemodynamic dysfunctions.

    Science.gov (United States)

    Nisar, Asim; Afzulpurkar, Nitin; Tuantranont, Adisorn; Mahaisavariya, Banchong

    2008-12-01

    In this paper, we present design of a transdermal drug delivery system for treatment of cardiovascular or hemodynamic disorders such as hypertension. The system comprises of integrated control electronics and microelectromechanical system devices such as micropump, micro blood pressure sensor and microneedle array. The objective is to overcome the limitations of oral therapy such as variable absorption profile and the need for frequent dosing, by fabricating a safe, reliable and cost effective transdermal drug delivery system to dispense various pharmacological agents through the skin for treatment of hemodynamic dysfunction such as hypertension. Moreover, design optimization of a piezoelectrically actuated valveless micropump is presented for the drug delivery system. Because of the complexity in analysis of piezoelectric micropump, which involves structural and fluid field couplings in a complicated geometrical arrangement, finite element (FE) numerical simulation rather than an analytical system has been used. The behavior of the piezoelectric actuator with biocompatible polydimethylsiloxane membrane is first studied by conducting piezoelectric analysis. Then the performance of the valveless micropump is analyzed by building a three dimensional electric-solid-fluid model of the micropump. The effect of geometrical dimensions on micropump characteristics and efficiency of nozzle/diffuser elements of a valveless micropump is investigated in the transient analysis using multiple code coupling method. The deformation results of the membrane using multifield code coupling analysis are in good agreement with analytical as well as results of single code coupling analysis of a piezoelectric micropump. The analysis predicts that to enhance the performance of the micropump, diffuser geometrical dimensions such as diffuser length, diffuser neck width and diffuser angle need to be optimized. Micropump flow rate is not strongly affected at low excitation frequencies from 10

  13. Catalytic micromotors and micropumps and their collective behavior

    Science.gov (United States)

    Ibele, Michael Edward

    The overarching goal which initiated this research was the desire to learn how to synthesize artificial micrometer- and nanometer-sized objects which have the ability to move autonomously in solution, and to be able to understand, predict, and control their movements. In the natural world, such motion is common. Bacteria, for instance, use flagella, cilia, or other mechanisms to chemotax to nutrient-rich regions of their environments. However, at the outset of this research, only a few simple examples of artificially powered motions on the microscale had been reported in the literature. This dissertation discusses the evolution of artificial catalytic micromotors and micropumps from the initial bimetallic-microrod design, which catalyzed the decomposition of hydrogen peroxide (H2O2), to the current state of the field, in which particle motion can also be powered by hydrazine-derived fuels or by ultraviolet light. Analyses of these new motors are presented, with particular emphasis given to the motormotor interactions which occur in solution and which give rise to collective behavior in dense populations of the motors. The first artificial autonomous micromotor ever synthesized consisted of a bimetallic microrod with spatially segregated gold and platinum segments. When placed in aqueous solutions containing H2O2, this microrod decomposed the H2O2 asymmetrically on its two metallic surfaces and powered its own motion through solution via self-electrophoresis. In this dissertation, it is shown that a similar self-electrophoretic mechanism is at play in a micropump system comprised of spatially segregated, lithographically patterned, palladium and gold features, which operates in solutions of either hydrazine (N2H4) or N,N-dimethylhydrazine [(CH 3)2N(NH3)]. While this new electrophoretic system is interesting from a theoretical standpoint, N2H4 is highly toxic, and the decision was made to move on to other more environmentally friendly systems. The bulk of this

  14. Peristaltic motion of third grade fluid in curved channel

    Institute of Scientific and Technical Information of China (English)

    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.

  15. Analysis on and Optimization of a Circular Piezoelectric Composite Laminate for a Micro-Pump Driver

    International Nuclear Information System (INIS)

    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

  16. Magnetohydrodynamic flow of generalized Maxwell fluids in a rectangular micropump under an AC electric field

    International Nuclear Information System (INIS)

    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

  17. Magnetohydrodynamic flow of generalized Maxwell fluids in a rectangular micropump under an AC electric field

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Endoscopy analysis for the peristaltic flow of nanofluids containing carbon nanotubes with heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Akbar, Noreen Sher [National University of Sciences and Technology, Islamabad (Pakistan)

    2015-07-01

    Cu-water nanofluid with carbon nanotubes is considered for the peristaltic flow in an endoscope. The peristaltic flow for nanofluid is modelled considering that the peristaltic rush wave is a sinusoidal wave that propagates along the walls of the tube. The governing equations for the proposed model are simplified by using the assumptions of long-wavelength and low Reynolds number. Exact solutions have been evaluated for velocity, temperature, and pressure gradient. Graphical results for the numerical values of the flow parameters, i.e. Hartmann number M, the solid volume fraction φ of the nanoparticles, Grashof number Gr, heat absorption parameter β, and radius of the inner tube ε, have been presented for the pressure difference, frictional forces, velocity profile, and temperature profile, and trapping phenomena have been discussed at the end of the article.

  19. Peristaltic transport of Carreau-Yasuda fluid in a curved channel with slip effects.

    Directory of Open Access Journals (Sweden)

    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.

  20. Peristaltic Pumping of Blood in micro-vessels of Non-uniform Cross-section

    CERN Document Server

    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.

  1. A novel micropump with fixed-geometry valves and low leakage flow

    Science.gov (United States)

    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.

  2. A novel fabrication process to release a valveless micropump on a flexible substrate

    OpenAIRE

    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...

  3. Deformation analysis of a film-overlapped micro-pump membrane structure

    International Nuclear Information System (INIS)

    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

  4. The NeuroMedicator—a micropump integrated with silicon microprobes for drug delivery in neural research

    International Nuclear Information System (INIS)

    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)

  5. The NeuroMedicator—a micropump integrated with silicon microprobes for drug delivery in neural research

    Science.gov (United States)

    Spieth, S.; Schumacher, A.; Kallenbach, C.; Messner, S.; Zengerle, R.

    2012-06-01

    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.

  6. Development of micropump-actuated negative pressure pinched injection for parallel electrophoresis on array microfluidic chip.

    Science.gov (United States)

    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

  7. Caterpillar locomotion-inspired valveless pneumatic micropump using a single teardrop-shaped elastomeric membrane

    KAUST Repository

    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.

  8. Study of valveless electromagnetic micropump by volume-of-fluid and OpenFOAM

    Science.gov (United States)

    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.

  9. Caterpillar locomotion-inspired valveless pneumatic micropump using a single teardrop-shaped elastomeric membrane.

    Science.gov (United States)

    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

  10. Flow Rate Driven by Peristaltic Movement in Plasmodial Tube of Physarum Polycephalum

    Science.gov (United States)

    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.

  11. The self-generated peristaltic motion of cascaded pneumatic actuators for micro pumps

    International Nuclear Information System (INIS)

    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

  12. Development of Stepper motor based Two DOF Robotic Arm Transferring Liquid using Peristaltic Pump

    Directory of Open Access Journals (Sweden)

    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.

  13. The self-generated peristaltic motion of cascaded pneumatic actuators for micro pumps

    Science.gov (United States)

    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.

  14. Peristaltic transport of a Maxwell fluid in a porous asymmetric channel through a porous medium

    Directory of Open Access Journals (Sweden)

    Safia Akram

    2014-12-01

    Full Text Available The present study investigates the peristaltic flow of a Maxwell fluid in a porous asymmetric channel through a porous medium. An analytical solution has been found using regular perturbation method. The stream function and average mean velocity are obtained. The graphical results are presented to discuss the physical behavior of various parameters appearing in the problem.

  15. Peristaltic flow of a Maxwell fluid in a channel with compliant walls

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Slip and heat transfer effects on peristaltic motion of a Carreau fluid in an asymmetric channel

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  17. Slip effects on the magnetohydrodynamic peristaltic flow of a maxwell fluid

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  18. A mathematical model for the peristaltic flow of chyme movement in small intestine.

    Science.gov (United States)

    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

  19. Peristaltic Flow of Phan-Thien-Tanner Fluid in an Asymmetric Channel with Porous Medium

    Directory of Open Access Journals (Sweden)

    Kuppalapalle Vajravelu

    2016-01-01

    Full Text Available 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, stream function and pressure gradient are obtained. The features of the flow characteristics are analyzed through graphs and the obtained results are discussed in detail. It is noticed that the peristaltic pumping gets reduced due to an increase in the phase difference of the traveling waves. It is also observed that the size of the trapping bolus is a decreasing function of the permeability parameter and the Weissenberg number. Furthermore, the results obtained for the flow characteristics reveal many interesting behaviors that warrant further study on the non-Newtonian fluid phenomena, especially the Peristaltic flow phenomena.

  20. The Structure of Wheel Check Valve Influence on Air Block Phenomenon of Piezoelectric Micro-Pump

    OpenAIRE

    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...

  1. Development and Application of a Diaphragm Micro-Pump with Piezoelectric Device

    OpenAIRE

    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...

  2. ac electrokinetic micropumps: The effect of geometrical confinement, Faradaic current injection, and nonlinear surface capacitance

    DEFF Research Database (Denmark)

    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....

  3. Simulation of the fluidic features for diffuser/nozzle involved in a PZT-based valveless micropump

    Institute of Scientific and Technical Information of China (English)

    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.

  4. Study on an alternating current electrothermal micropump for microneedle-based fluid delivery systems

    Science.gov (United States)

    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.

  5. Lattice Boltzmann simulation of thermofluidic transport phenomena in a DC magnetohydrodynamic (MHD) micropump.

    Science.gov (United States)

    Chatterjee, Dipankar; Amiroudine, Sakir

    2011-02-01

    A comprehensive non-isothermal Lattice Boltzmann (LB) algorithm is proposed in this article to simulate the thermofluidic transport phenomena encountered in a direct-current (DC) magnetohydrodynamic (MHD) micropump. Inside the pump, an electrically conducting fluid is transported through the microchannel by the action of an electromagnetic Lorentz force evolved out as a consequence of the interaction between applied electric and magnetic fields. The fluid flow and thermal characteristics of the MHD micropump depend on several factors such as the channel geometry, electromagnetic field strength and electrical property of the conducting fluid. An involved analysis is carried out following the LB technique to understand the significant influences of the aforementioned controlling parameters on the overall transport phenomena. In the LB framework, the hydrodynamics is simulated by a distribution function, which obeys a single scalar kinetic equation associated with an externally imposed electromagnetic force field. The thermal history is monitored by a separate temperature distribution function through another scalar kinetic equation incorporating the Joule heating effect. Agreement with analytical, experimental and other available numerical results is found to be quantitative.

  6. A Comparative Study of Nozzle/Diffuser Micropumps with Novel Valves

    Directory of Open Access Journals (Sweden)

    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.

  7. Peristaltic Pumping of Blood Through Small Vessels of Varying Cross-Section

    Science.gov (United States)

    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.

  8. Efficient worm-like locomotion: slip and control of soft-bodied peristaltic robots

    International Nuclear Information System (INIS)

    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)

  9. Magnetic Field and Gravity Effects on Peristaltic Transport of a Jeffrey Fluid in an Asymmetric Channel

    Directory of Open Access Journals (Sweden)

    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.

  10. Effect of Wall Properties on the Peristaltic Flow of a Non-Newtonian Fluid

    Directory of Open Access Journals (Sweden)

    Maryiam Javed

    2014-01-01

    Full Text Available The effect of wall properties is analyzed on the peristaltic motion of a Burgers’ fluid. Sinusoidal waves are considered on the channel walls. Small amplitude assumption is taken into account to solve the required boundary value problem. Various flow parameters of interest are sketched and discussed through graphs. Comparative study of the mean velocity for different fluid models is presented the mean velocity is found maximum in viscous fluid when compared with the Maxwell, Oldroyd-B and Burgers’ fluids.

  11. Peristaltic transport of Johnson-Segalman fluid under effect of a magnetic field

    Directory of Open Access Journals (Sweden)

    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.

  12. Effect of induced magnetic field on peristaltic flow of a micropolar fluid in an asymmetric channel

    OpenAIRE

    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...

  13. A Mathematical Model for Studying the Slip Effect on Peristaltic Motion with Heat and Mass Transfer

    Institute of Scientific and Technical Information of China (English)

    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.

  14. Non-Newtonian effects in the peristaltic flow of a Maxwell fluid

    OpenAIRE

    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...

  15. Peristaltic Creeping Flow of Power Law Physiological Fluids through a Nonuniform Channel with Slip Effect

    OpenAIRE

    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...

  16. Gastrointestinal monitor: automatic titration of jejunal inflow to match peristaltic outflow.

    Science.gov (United States)

    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

  17. Particle motion in unsteady two-dimensional peristaltic flow with application to the ureter

    Science.gov (United States)

    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.

  18. Thermally developing MHD peristaltic transport of nanofluids with velocity and thermal slip effects

    Science.gov (United States)

    Sher Akbar, Noreen; Bintul Huda, A.; Tripathi, D.

    2016-09-01

    We investigate the velocity slip and thermal slip effects on peristaltically driven thermal transport of nanofluids through the vertical parallel plates under the influence of transverse magnetic field. The wall surface is propagating with sinusoidal wave velocity c. The flow characteristics are governed by the mass, momentum and energy conservation principle. Low Reynolds number and large wavelength approximations are taken into consideration to simplify the non-linear terms. Analytical solutions for axial velocity, temperature field, pressure gradient and stream function are obtained under certain physical boundary conditions. Two types of nanoparticles, SiO2 and Ag, are considered for analysis with water as base fluid. This is the first article in the literature that discusses the SiO2 and Ag nanoparticles for a peristaltic flow with variable viscosity. The effects of physical parameters on velocity, temperature, pressure and trapping are discussed. A comparative study of SiO2 nanofluid, Ag nanofluid and pure water is also presented. This model is applicable in biomedical engineering to make thermal peristaltic pumps and other pumping devices like syringe pumps, etc. It is observed that pressure for pure water is maximum and pressure for Ag nanofluid is minimum.

  19. Peristaltic flow in non-uniform vessels of the micro-circulatory system

    CERN Document Server

    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...

  20. Design and Analysis of Piezoelectric Micro-Pump Using Traveling-Wave

    International Nuclear Information System (INIS)

    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

  1. Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields

    International Nuclear Information System (INIS)

    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.

  2. Characteristics of electrostatic gas micro-pump with integrated polyimide passive valves

    International Nuclear Information System (INIS)

    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)

  3. Characteristics of electrostatic gas micro-pump with integrated polyimide passive valves

    Science.gov (United States)

    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.

  4. A magnetic shape memory micropump: contact-free, and compatible with PCR and human DNA profiling

    International Nuclear Information System (INIS)

    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)

  5. Experimental study of thermally-driven micro-pump using stepped laser

    Institute of Scientific and Technical Information of China (English)

    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.

  6. NUMERICAL STUDY OF PERIODICAL FLOWS OF PIEZOELECTRIC VALVELESS MICROPUMP FOR BIOCHIPS

    Institute of Scientific and Technical Information of China (English)

    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.

  7. A magnetic shape memory micropump: contact-free, and compatible with PCR and human DNA profiling

    Science.gov (United States)

    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.

  8. A novel fabrication process to realize a valveless micropump on a flexible substrate

    Science.gov (United States)

    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.

  9. Tolerability, safety and efficacy of Iloprost infusion without peristaltic pump in systemic sclerosis

    Directory of Open Access Journals (Sweden)

    S. Tosi

    2011-09-01

    Full Text Available Objective. To evaluate safety, tolerability and efficacy on Raynaud’s phenomenon (Rp of iloprost infusion without peristaltic pump in patients with systemic sclerosis (SSc. Patients and methods. The inclusion criteria were diagnosis of SSc, age between 18 and 65 years, presence of Rp, and absence of any controindication to the use of iloprost. The treatment was carried out in a day hospital setting and consisted first of 5 consecutive days of iloprost infusion (from an initial dose of 1.0 ng/Kg/min up to 2 ng/kg/min, and then of 2 days of infusions at the maximum possible dose every 45 days for one year. All of the adverse events were carefully recorded and the changes in the Rp were measured by a 5 grade scale (worsened, unmodified, slightly improved, very improved, disappeared. Results. Thirty-eight SSc patients (all females, mean age 49 years (range 18.5-65, disease duration 1.5 years (range 0.5-10.8 were enrolled in the study. During the first cycle of therapy, 14 avderse events occurred in 11 (28.9% patients and during the next cycles, 3 adverse events were seen in 3 (7.9% patients. In all of the cases they were mild and transient. Rp was considered very improved in 15 (39.5% patients, slightly improved in 13 (34.2%, unmodified in 8 (21% and worse in 2 (5.2%. Discussion. In this study intravenous iloprost without peristaltic pump proved to be safe, well tolerated, and as effective as traditional infusion through peristaltic pump in improving Rp in patients with SSc.

  10. Hall and ion slip effects on peristaltic flow of Jeffrey nanofluid with Joule heating

    Science.gov (United States)

    Hayat, T.; Shafique, Maryam; Tanveer, A.; Alsaedi, A.

    2016-06-01

    This paper addresses mixed convective peristaltic flow of Jeffrey nanofluid in a channel with complaint walls. The present investigation includes the viscous dissipation, thermal radiation and Joule heating. Hall and ion slip effects are also taken into account. 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, Hall and ion slip parameters are investigated in detail. It is observed that velocity increases and temperature decreases with Hall and ion slip parameters. Further the thermal radiation on temperature has qualitatively similar role to that of Hall and ion slip effects.

  11. Peristaltic flow of Johnson-Segalman fluid in asymmetric channel with convective boundary conditions

    Institute of Scientific and Technical Information of China (English)

    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.

  12. A Peristaltic Micro Pump Driven by a Rotating Motor with Magnetically Attracted Steel Balls

    OpenAIRE

    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 ...

  13. Peristaltic flow with thermal conductivity of H2O + Cu nanofluid and entropy generation

    Directory of Open Access Journals (Sweden)

    Noreen Sher Akbar

    2015-01-01

    Full Text Available In this article, it is opted to investigate the effects of entropy and induced magnetic field for the peristaltic flow of copper water fluid in the asymmetric horizontal channel , the mathematical formulation is presented, the resulting equations are solved exactly. The obtained expressions for pressure gradient , pressure rise, temperature, axial magnetic field, current density, velocity phenomenon entropy generation number and Bejan number are described through graphs for various pertinent parameters. The streamlines are drawn for some physical quantities to discuss the trapping phenomenon.

  14. Peristaltic transport of Conducting Bingham fluid in contact with a Newtonian fluid in a channel

    Directory of Open Access Journals (Sweden)

    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

  15. Magnetohydrodynamic Peristaltic Flow of a Pseudoplastic Fluid in a Curved Channel

    Science.gov (United States)

    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.

  16. Radiative Peristaltic Flow of Jeffrey Nanofluid with Slip Conditions and Joule Heating

    Science.gov (United States)

    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

  17. Magnetohydrodynamic peristaltic flow of a hyperbolic tangent fluid in a vertical asymmetric channel with heat transfer

    Institute of Scientific and Technical Information of China (English)

    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.

  18. Effect of Slip on Peristaltic Flow of Powell-Eyring Fluid in a Symmetric Channel

    Directory of Open Access Journals (Sweden)

    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.

  19. Mathematical Analysis for Peristaltic Flow of Two Phase Nanofluid in a Curved Channel

    Science.gov (United States)

    Nadeem, S.; Iqra, Shahzadi

    2015-11-01

    This paper describes the theoretical analysis for peristaltic motion of water base nanofluid containing distinct types of the nanoparticles like Cu, TiO2, and Al2O3. Equations of nano fluid are modelled and simplified by constructing the suppositions of low Reynolds number as well as long wave length. The reduced equations are solved exactly. Solutions are represented through graphs. Outcomes for the velocity, temperature, pressure rise and stream lines are analyzed graphically. The work presented here is based on the fictitious values, however some other values can be tested experimentally.

  20. The Mathematical Analysis for Peristaltic Flow of Hyperbolic Tangent Fluid in a Curved Channel

    Institute of Scientific and Technical Information of China (English)

    S.Nadeem; E.N.Maraj

    2013-01-01

    In the present paper,we have investigated the peristaltic flow of hyperbolic tangent fluid in a curved channel.The governing equations of hyperbolic tangent fluid model for curved channel are derived including the effects of curvature.The highly nonlinear partial differential equations are simplified by using the wave frame transformation,long wave length and low Reynolds number assumptions.The reduced nonlinear partial differential equation is solved analytically with the help of homotopy perturbation method (HPM).The physical features of pertinent parameters have been discussed by plotting the graphs of pressure rise and stream functions.

  1. Peristaltic transport of a fractional Burgers' fluid with variable viscosity through an inclined tube

    Science.gov (United States)

    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.

  2. Peristaltic flow of a Johnson-Segalman fluid through a deformable tube

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yongqi [Darmstadt University of Technology, Department of Mechanical Engineering, Darmstadt (Germany); Universitaet fuer Bodenkultur, Institute of Geotechnical Engineering, Vienna (Austria); Hayat, Tasawar [Quaid-i-Azam University, Mathematics Department, Islamabad (Pakistan); Hutter, Kolumban [ETH Zuerich, VAW, Zuerich (Switzerland)

    2007-09-15

    To understand theoretically the flow properties of physiological fluids we have considered as a model the peristaltic motion of a Johnson-Segalman fluid in a tube with a sinusoidal wave traveling down its wall. The perturbation solution for the stream function is obtained for large wavelength and small Weissenberg number. The expressions for the axial velocity, pressure gradient, and pressure rise per wavelength are also constructed. The general solution of the governing nonlinear partial differential equation is given using a transformation method. The numerical solution is also obtained and is compared with the perturbation solution. Numerical results are demonstrated for various values of the physical parameters of interest. (orig.)

  3. Mixed convection peristaltic flow of third order nanofluid with an induced magnetic field.

    Directory of Open Access Journals (Sweden)

    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.

  4. Peristaltic flow in an asymmetric channel with convective boundary conditions and Joule heating

    Institute of Scientific and Technical Information of China (English)

    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.

  5. Investigation of a piezoelectric valveless micropump with an integrated stainless-steel diffuser/nozzle bulge-piece design

    Science.gov (United States)

    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.

  6. Investigation of a piezoelectric valveless micropump with an integrated stainless-steel diffuser/nozzle bulge-piece design

    International Nuclear Information System (INIS)

    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)

  7. Effect of Rotation and Magnetic Field through Porous Medium on Peristaltic Transport of a Jeffrey Fluid in Tube

    Directory of Open Access Journals (Sweden)

    S. R. Mahmoud

    2011-01-01

    Full Text Available This paper is concerned with the analysis of peristaltic motion of a Jeffrey fluid in a tube with sinusoidal wave travelling down its wall. The effect of rotation, porous medium, and magnetic field on peristaltic transport of a Jeffrey fluid in tube is studied. The fluid is electrically conducting in the presence of rotation and a uniform magnetic field. An analytic solution is carried out for long wavelength, axial pressure gradient, and low Reynolds number considerations. The results for pressure rise and frictional force per wavelength were obtained, evaluated numerically, and discussed briefly.

  8. Soret and Dufour Effects on MHD Peristaltic Flow of Jeffrey Fluid in a Rotating System with Porous Medium

    Science.gov (United States)

    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

  9. Soret and Dufour Effects on MHD Peristaltic Flow of Jeffrey Fluid in a Rotating System with Porous Medium.

    Science.gov (United States)

    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

  10. Influence of magnetic field on peristaltic flow of a Casson fluid in an asymmetric channel: Application in crude oil refinement

    Science.gov (United States)

    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.

  11. A High-Performance, Low-Cost Laser Shutter using a Piezoelectric Cantilever Actuator

    CERN Document Server

    Bowden, W; Baird, P E G; Gill, P

    2016-01-01

    We report the design and characterization of an optical shutter based on a piezoelectric cantilever. Compared to conventional electro-magnetic shutters, the device is intrinsically low power and acoustically quiet. The cantilever position is controlled by a high-voltage op-amp circuit for easy tuning of the range of travel, and mechanical slew rate, which enables a factor of 30 reduction in mechanical noise compared to a rapidly switched device. We achieve shuttering rise and fall times of 11 $\\mu$s, corresponding to mechanical slew rates of 1.3 $\\textrm{ ms}^{-1}$, with an timing jitter of less than 1 $\\mu$s. When used to create optical pulses, we achieve minimum pulse durations of 250 $\\mu$s. The reliability of the shutter was investigated by operating continuously for one week at 10 Hz switching rate. After this period, neither the shutter delay or actuation speed had changed by a notable amount. We also show that the high-voltage electronics can be easily configured as a versatile low-noise, high-bandwidt...

  12. Nanoporous-Gold-Based Hybrid Cantilevered Actuator Dealloyed and Driven by A Modified Rotary Triboelectric Nanogenerator

    Science.gov (United States)

    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

  13. The Relation between Peristaltic and Segmental Contraction, Mixing, and Absorption in the Small Intestine

    Science.gov (United States)

    Banco, Gino; Brasseur, James; Wang, Yanxing; Ailiani, Amit; Neuberger, Thomas; Webb, Andrew

    2009-11-01

    The physiology and mechanics of the small intestine originates with lumen-scale fluid motions generated by enterically controlled muscle wall contractions. Although complex in appearance, we have shown with principle component decomposition of gut motion from a rat model that simpler component structure may integrate to produce basic peristaltic and segmental motions. To couple these measured modes with fluid mixing and nutrient absorption we have developed 2-D and axisymmetric models of the gut using the lattice-Boltzmann framework with scalar and second order moving boundary conditions. Previous models indicated that peristalsis is detrimental to absorption and therefore that gut motility is likely bimodal, transitioning between peristalsis and segmental modes to optimize the transport of chyme vs. nutrient absorption. However we have since discovered that more complex control is possible due to potential transitions between ``trapped'' vs. ``nontrapped'' peristaltic fluid motions, depending on occlusion ratio. These transitions lead to an important distinction between 2-D and axisymmetric models and indicate that gut motility may be more finely controlled than previously thought. [Supported by NSF

  14. Slip Effects on Peristaltic Transport of a Particle-Fluid Suspension in a Planar Channel

    Directory of Open Access Journals (Sweden)

    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.

  15. Peristaltic Transport of a Rheological Fluid: Model for Movement of Food Bolus Through Esophagus

    CERN Document Server

    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...

  16. Williamson Fluid Model for the Peristaltic Flow of Chyme in Small Intestine

    Directory of Open Access Journals (Sweden)

    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.

  17. A study of unsteady physiological magneto-fluid flow and heat transfer through a finite length channel by peristaltic pumping.

    Science.gov (United States)

    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

  18. A study of unsteady physiological magneto-fluid flow and heat transfer through a finite length channel by peristaltic pumping.

    Science.gov (United States)

    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.

  19. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Multi-Phase Flow and Heat Transfer of a Micro-Pump Thermally Driven by a Multi-Output Pulse Laser

    Institute of Scientific and Technical Information of China (English)

    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.

  1. 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

    Institute of Scientific and Technical Information of China (English)

    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。

  2. A new working principle for ac electro-hydrodynamic on-chip micro-pumps

    International Nuclear Information System (INIS)

    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

  3. The Structure of Wheel Check Valve Influence on Air Block Phenomenon of Piezoelectric Micro-Pump

    Directory of Open Access Journals (Sweden)

    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%.

  4. A MEMS-based silicon micropump with intersecting channels and integrated hotwires

    International Nuclear Information System (INIS)

    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

  5. A MEMS-based silicon micropump with intersecting channels and integrated hotwires

    Science.gov (United States)

    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.

  6. Development and Application of a Diaphragm Micro-Pump with Piezoelectric Device

    CERN Document Server

    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...

  7. Insulin Micropump with Embedded Pressure Sensors for Failure Detection and Delivery of Accurate Monitoring

    Directory of Open Access Journals (Sweden)

    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.

  8. Topology and shape optimization of induced-charge electro-osmotic micropumps

    Energy Technology Data Exchange (ETDEWEB)

    Gregersen, M M; Okkels, F; Bruus, H [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Bazant, M Z [Departments of Chemical Engineering and Mathematics, MIT, Cambridge, MA 02139 (United States)], E-mail: Henrik.Bruus@nanotech.dtu.dk

    2009-07-15

    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 net induced electro-osmotic flow rate through the electrolytic capacitor in the direction parallel to the capacitor plates. Once found, the performance of the topology-optimized geometries has been validated by transferring them to conventional electrokinetic models not relying on the artificial 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.

  9. PV-Li-ion-micropump membrane systems for portable personal desalination

    Directory of Open Access Journals (Sweden)

    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.

  10. A Mathematical Model for Peristaltic Transport of Micro-Polar Fluids

    Directory of Open Access Journals (Sweden)

    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.

  11. Simultaneous effects of slip and wall properties on MHD peristaltic motion of nanofluid with Joule heating

    Science.gov (United States)

    Hayat, T.; Nisar, Z.; Ahmad, B.; Yasmin, H.

    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.

  12. Peristaltic Transport of Prandtl-Eyring Liquid in a Convectively Heated Curved Channel.

    Science.gov (United States)

    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

  13. Mixed Convective Peristaltic Flow of Water Based Nanofluids with Joule Heating and Convective Boundary Conditions.

    Science.gov (United States)

    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

  14. Effect of induced magnetic field on peristaltic flow of a micropolar fluid in an asymmetric channel

    CERN Document Server

    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.

  15. Peristaltic flow of a reactive viscous fluid through a porous saturated channel and convective cooling conditions

    Science.gov (United States)

    Asghar, S.; Hussain, Q.; Hayat, T.; Alsaedi, A.

    2015-07-01

    This article addresses the heat transfer in a peristaltic flow of a reactive combustible viscous fluid through a porous saturated medium. The flow here is induced because of travelling waves along the channel walls. It is assumed that exothermic chemical reactions take place within the channel under the Arrhenius kinetics and the convective heat exchange with the ambient medium at the surfaces of the channel walls follows Newton's law of cooling. The analysis is carried out in the presence of viscous dissipation and without consumption of the material. The governing equations are formulated by employing the long-wavelength approximation. Closed-form solutions for the stream function, axial velocity, and axial pressure gradient are obtained. It is found that the temperature decreases at high Biot numbers, and the Nusselt number increases with increasing reaction parameter. The Biot number and reaction parameter produce the opposite effects on the Nusselt number.

  16. Simultaneous effects of slip and wall properties on MHD peristaltic motion of nanofluid with Joule heating

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Peristaltic flow of a micropolar fluid with nano particles in small intestine

    Science.gov (United States)

    Akbar, Noreen Sher; Nadeem, S.

    2013-12-01

    The present article analyzed the peristaltic flow of a nanofluid in a uniform tube for micropolar fluid. The governing equations for proposed model are developed in cylindrical coordinates system. The flow is discussed in a wave frame of reference moving with velocity of the wave c. Under the assumptions of longwave length the reduced coupled nonlinear differential equations of momentum, energy, and concentrations are solved by Homotopy perturbation method is used to get the solutions for velocity, temperature, nano particle, microrotation component. The solutions consists Brownian motion number N b, thermophoresis number N t, local temperature Grashof number B r and local nano particle Grashof number G r . The effects of various parameters involved in the problem are investigated for pressure rise, pressure gradient, temperature and concentration profile. Five different waves are taken into account for analysis. Streamlines have been plotted at the end of the article.

  18. Characteristics of Jeffrey fluid model for peristaltic flow of chyme in small intestine with magnetic field

    Science.gov (United States)

    Akbar, Noreen Sher; Nadeem, S.; Lee, Changhoon

    In the present article we have analyzed the Jeffrey fluid model for the peristaltic flow of chyme in the small intestine. We have formulated the problem using two non-periodic sinusoidal waves of different wavelengths propagating with same speed c along the outer wall of the tube. Governing equations for the problem under consideration have been simplified under the assumptions of long wavelength and low Reynolds number approximation (such assumptions are consistent since Re (Reynolds number) is very small and long wavelength approximation also exists in the small intestine). Exact solutions have been calculated for velocity and pressure rise. Physical behavior of different parameters of Jeffrey fluid has been presented graphically for velocity, pressure rise, pressure gradient and frictional forces. The trapping phenomenon is also discussed at the end of the article.

  19. Simulations of peristaltic slip-flow of hydromagnetic bio-fluid in a curved channel

    Science.gov (United States)

    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).

  20. Peristaltic Transport of Prandtl-Eyring Liquid in a Convectively Heated Curved Channel.

    Directory of Open Access Journals (Sweden)

    Tasawar Hayat

    Full Text Available 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.

  1. Peristaltic Pumping near Post-CME Supra-Arcade Current Sheets

    CERN Document Server

    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 ...

  2. A Peristaltic Micro Pump Driven by a Rotating Motor with Magnetically Attracted Steel Balls

    Directory of Open Access Journals (Sweden)

    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.

  3. Peristaltic motion of Johnson-Segalman fluid in a curved channel with slip conditions.

    Directory of Open Access Journals (Sweden)

    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.

  4. Peristaltic motion of Johnson-Segalman fluid in a curved channel with slip conditions.

    Science.gov (United States)

    Hina, Sadia; Mustafa, Meraj; Hayat, Tasawar

    2014-01-01

    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.

  5. Simulations of peristaltic slip-flow of hydromagnetic bio-fluid in a curved channel

    Directory of Open Access Journals (Sweden)

    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.

  6. ZnO film based surface acoustic wave micro-pump

    International Nuclear Information System (INIS)

    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

  7. Bi-directional ACET micropump for on-chip biological applications.

    Science.gov (United States)

    Vafaie, Reza Hadjiaghaie; Ghavifekr, Habib Badri; Van Lintel, Harald; Brugger, Juergen; Renaud, Philippe

    2016-03-01

    The ability to control and pump high ionic strength fluids inside microchannels forms a major advantage for clinical diagnostics and drug screening processes, where high conductive biological and physiological buffers are used. Despite the known potential of AC electro-thermal (ACET) effect in different biomedical applications, comparatively little is known about controlling the velocity and direction of fluid inside the chip. Here, we proposed to discretize the conventional electrodes to form various asymmetric electrode structures in order to control the fluid direction by simple switching the appropriate electric potential applied to the discretized electrodes. The ACET pumping effect was numerically studied by solving electrical, thermal and hydrodynamic multi-physic coupled equations to optimize the geometrical dimensions of the discretized system. PBS solutions with different ionic strength were seeded with 1 μm sized fluorescent particles and electrothermally driven fluid motion was observed inside the channel for different electrode structures. Experimental analyses confirm that the proposed micropump is efficient for a conductivity range between 0.1 and 1 S/m and the efficiency improves by increasing the voltage amplitude. Behavior of the proposed electrode-electrolyte system is discussed by lumped circuit model. Frequency response of system illustrated that the optimal frequency range increases by increasing the conductivity of medium. For 0.18 S/m PBS solution, the constant pumping effect was observed at frequency range between 100 kHz and 1 MHz, while frequency range of 100 kHz to 5 MHZ was observed for 0.42 S/m. The characteristics of experimental results were in good agreement with the theoretical model. PMID:26790840

  8. Studies on spectroscopy of glycerol in THz range using microfluidic chip-integrated micropump

    Science.gov (United States)

    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.

  9. Effects of heat transfer on peristaltic motion of Oldroyd fluid in the presence of inclined magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Afsar Khan, A. [Department of Mathematics and Statistics, FBAS, IIUI, Islamabad (Pakistan); Ellahi, R., E-mail: rahmatellahi@yahoo.com [Department of Mathematics and Statistics, FBAS, IIUI, Islamabad (Pakistan); Department of Mechanical Engineering, Bourns Hall, University of California Riverside, CA 92521 (United States); Mudassar Gulzar, M. [National University of Sciences and Technology, College of Electrical and Mechanical Engineering Islamabad (Pakistan); Sheikholeslami, Mohsen [Department of Mechanical Engineering, Babol University of Technology, Babol (Iran, Islamic Republic of)

    2014-12-15

    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.

  10. Peristaltic Transport of a Physiological Fluid in an Asymmetric Porous Channel in the Presence of an External Magnetic Field

    OpenAIRE

    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 ...

  11. Simultaneous effects of Hall and convective conditions on peristaltic flow of couple-stress fluid in an inclined asymmetric channel

    Indian Academy of Sciences (India)

    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.

  12. Transient magneto-peristaltic flow of couple stress biofluids: a magneto-hydro-dynamical study on digestive transport phenomena.

    Science.gov (United States)

    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

  13. Transient magneto-peristaltic flow of couple stress biofluids: a magneto-hydro-dynamical study on digestive transport phenomena.

    Science.gov (United States)

    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.

  14. Study of the Behavior of a Bell-Shaped Colonic Self-Expandable NiTi Stent under Peristaltic Movements

    Directory of Open Access Journals (Sweden)

    Sergio Puértolas

    2013-01-01

    Full Text Available Managing bowel obstruction produced by colon cancer requires an emergency intervention to patients usually in poor conditions, and it requires creating an intestinal stoma in most cases. Regardless of that the tumor may be resectable, a two-stage surgery is mandatory. To avoid these disadvantages, endoscopic placement of self-expanding stents has been introduced more than 10 years ago, as an alternative to relieve colonic obstruction. It can be used as a bridge to elective single-stage surgery avoiding a stoma or as a definitive palliative solution in patients with irresectable tumor or poor estimated survival. Stents must be capable of exerting an adequate radial pressure on the stenosed wall, keeping in mind that stent must not move or be crushed, guaranteeing an adequate lumen when affected by peristaltic waves. A finite element simulation of bell-shaped nitinol stent functionality has been done. Catheter introduction, releasing at position, and the effect of peristaltic wave were simulated. To check the reliability of the simulation, a clinical experimentation with porcine specimens was carried out. The stent presented a good deployment and flexibility. Stent behavior was excellent, expanding from the very narrow lumen corresponding to the maximum peristaltic pressure to the complete recovery of operative lumen when the pressure disappears.

  15. A Peristaltic Pump Integrated on a 100% Glass Microchip Using Computer Controlled Piezoelectric Actuators

    Directory of Open Access Journals (Sweden)

    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.

  16. Peristaltic transport of a generalized Burgers’ fluid: Application to the movement of chyme in small intestine

    Science.gov (United States)

    Tripathi, Dharmendra; Pandey, S. K.; Das, S.

    2011-07-01

    The present investigation deals with the peristaltic transport of generalized Burgers' fluid with fractional element model in a channel. The analysis is carried out under long wavelength and low Reynolds number assumptions. An efficient mathematical tool, namely, Adomian decomposition method, is used to obtain the analytical approximate solutions of the fractional differential equation. The channel is governed by the propagation of sinusoidal waves that help the walls contract and relax but not expand beyond the natural boundary. The expressions of axial velocity, volume flow rate and pressure gradient are obtained. The effects of the fractional parameters and the material constants are discussed on pressure difference and the friction force across one wavelength. The comparative studies for various models of viscoelastic fluids such as fractional generalized Burgers' model, generalized Burgers' model, fractional Burgers' model and Burgers' model are performed. It is inferred that the movement of viscoelastic chyme with generalized Burgers' model through the small intestine is favorable in comparison to the movement of viscoelastic chyme with fractional generalized Burgers' model.

  17. Motion generation of peristaltic mobile robot with particle swarm optimization algorithm

    Science.gov (United States)

    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.

  18. Hall and ion slip effects on peristaltic flow and heat transfer analysis with Ohmic heating

    Institute of Scientific and Technical Information of China (English)

    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.

  19. 蠕动泵在化学反应过程中的应用%The Peristaltic Pump's Application in the Chemical Reaction Process

    Institute of Scientific and Technical Information of China (English)

    冯雨静; 张晓桂; 高波

    2013-01-01

    为了减轻化学实验人员的劳动强度,提出采用蠕动泵进料。论述了蠕动泵的发展现状,从化学反应过程的应用角度详细阐述了蠕动泵的应用特点和优势,表明蠕动泵在化学反应过程中应用的可行性,简述了蠕动泵软管的应用要求和蠕动泵在应用过程中的控制方法。%In order to reduce the labor intensity of chemical ex-periments,a peristaltic pump feeding method is proposed. This article introduces the peristaltic pump's development status and working principle. Its applying characteristic and advantage in the chemical reaction process are described in details to show the feasibility of the peristaltic pump's application in the chemical reaction process. In addition, this article expounds the application requirements of peristaltic pump hose and the controlling ways and means when applying the peristaltic pump.

  20. 5-HT3 and 5-HT4 antagonists inhibit peristaltic contractions in guinea-pig distal colon by mechanisms independent of endogenous 5-HT

    Directory of Open Access Journals (Sweden)

    Tiong Cheng Sia

    2013-08-01

    Full Text Available Recent studies have shown that endogenous serotonin is not required for colonic peristalsis in vitro, nor gastrointestinal (GI transit in vivo. However, antagonists of 5-Hydroxytryptamine (5-HT receptors can inhibit peristalsis and GI-transit in mammals, including humans. This raises the question of how these antagonists inhibit GI-motility and transit, if depletion of endogenous 5-HT does not cause any significant inhibitory changes to either GI-motility or transit ? We investigated the mechanism by which 5-HT3 and 5-HT4 antagonists inhibit distension-evoked peristaltic contractions in guinea-pig distal colon. In control animals, repetitive peristaltic contractions of the circular muscle were evoked in response to fixed fecal pellet distension. Distension-evoked peristaltic contractions were unaffected in animals with mucosa and submucosal plexus removed, that were also treated with reserpine (to deplete neuronal 5-HT. In control animals, peristaltic contractions were blocked temporarily by ondansetron (1-10µM and SDZ-205-557 (1-10µM in many animals. Interestingly, after this temporary blockade, and whilst in the continued presence of these antagonists, peristaltic contractions recovered, with characteristics no different from controls. Surprisingly, similar effects were seen in mucosa-free preparations, which had no detectable 5-HT, as detected by mass spectrometry. In summary, distension-evoked peristaltic reflex contractions of the circular muscle layer of the guinea-pig colon can be inhibited temporarily, or permanently, in the same preparation by selective 5-HT3 and 5-HT4 antagonists, depending on the concentration of the antagonists applied. These effects also occur in preparations that lack any detectable 5-HT. We suggest caution should be exercised when interpreting the effects of 5-HT3 and 5-HT4 antagonists; and the role of endogenous 5-HT, in the generation of distension-evoked colonic peristalsis.

  1. Peristaltic flow of a couple stress fluid under the effect of induced magnetic field in an asymmetric channel

    Energy Technology Data Exchange (ETDEWEB)

    Nadeem, Sohail; Akram, Safia [Quaid-i-Azam University, Department of Mathematics, Islamabad (Pakistan)

    2011-01-15

    The present paper investigates the peristaltic transport of a couple stress fluid in an asymmetric channel with the effect of the induced magnetic field. The exact solutions of momentum and the magnetic field equations have been calculated under the assumptions of long wave length and low but finite Reynolds number. The expression for pressure rise has been computed numerically using mathematics software Mathematica. The graphical results have been presented to discuss the physical behavior of various physical parameters of interest. Finally, the trapping phenomena have been discussed for various physical parameters. (orig.)

  2. Convective heat and mass transfer on MHD peristaltic flow of Williamson fluid with the effect of inclined magnetic field

    Science.gov (United States)

    Veera Krishna, M.; Swarnalathamma, B. V.

    2016-05-01

    In this paper, we discussed the peristaltic MHD flow of an incompressible and electrically conducting Williamson fluid in a symmetric planar channel with heat and mass transfer under the effect of inclined magnetic field. Viscous dissipation and Joule heating are also taken into consideration. Mathematical model is presented by using the long wavelength and low Reynolds number approximations. The differential equations governing the flow are highly nonlinear and thus perturbation solution for small Weissenberg number (We Effects of the heat and mass transfer on the longitudinal velocity, temperature and concentration are studied in detail. Main observations are presented in the concluding section. The streamlines pattern is also given due attention.

  3. Effect of an inclined magnetic field on peristaltic flow of Williamson fluid in an inclined channel with convective conditions

    Science.gov (United States)

    Hayat, T.; Bibi, Shahida; Rafiq, M.; Alsaedi, A.; Abbasi, F. M.

    2016-03-01

    This paper deals with the influence of inclined magnetic field on peristaltic flow of an incompressible Williamson fluid in an inclined channel with heat and mass transfer. Convective conditions of heat and mass transfer are employed. Viscous dissipation and Joule heating are taken into consideration. Mathematical modeling also includes Soret and Dufour effects. Channel walls have compliant properties. Analysis has been carried out through long wavelength and low Reynolds number approach. Resulting problems are solved for small Weissenberg number. Impacts of variables reflecting the salient features of wall properties, Biot numbers and Soret and Dufour on the velocity, temperature, concentration and heat transfer coefficient are pointed out. Trapping phenomenon is also analyzed.

  4. Numerical Analysis for Peristaltic Motion of MHD Eyring-Prandtl Fluid in an Inclined Symmetric Cannel with Inclined Magnetic Field

    Directory of Open Access Journals (Sweden)

    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

  5. Analytical Analysis of Peristaltic Flow of a Six Constant Jeffreys Model of Fluid in an Inclined Planar Channel

    Directory of Open Access Journals (Sweden)

    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.

  6. Peristaltic Transport of a Physiological Fluid in an Asymmetric Porous Channel in the Presence of an External Magnetic Field

    CERN Document Server

    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.

  7. Mixed convective heat and mass transfer analysis for peristaltic transport in an asymmetric channel with Soret and Dufour effects

    Institute of Scientific and Technical Information of China (English)

    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.

  8. Combined effect of couple stresses and heat and mass transfer on peristaltic flow with slip conditions in a tube.

    Science.gov (United States)

    Sobh, Ayman M

    2013-10-01

    In this article, the influence of heat and mass transfer on peristaltic transport of a couple stress fluid in a uniform tube with slip conditions on the wall is studied. The problem can model the blood flow in living creatures. Under long wavelength approximation and zero Reynolds number, exact solutions for the axial velocity component, pressure gradient, and both temperature and concentration fields are derived. The pressure rise is computed numerically and explained graphically. Moreover, effects of various physical parameters of the problem on temperature distribution, concentration field, and trapping are studied and discussed graphically.

  9. Detection of Crohn's disease: Comparison of CT and MR enterography without anti-peristaltic agents performed on the same day

    International Nuclear Information System (INIS)

    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.

  10. Effect of radiation and magnetic field on peristaltic transport of nanofluids through a porous space in a tapered asymmetric channel

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Peristaltic hemodynamic flow of couple stress fluid through a porous medium under the influence of magnetic field with slip effect

    Science.gov (United States)

    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.

  12. Peristaltic transport of MHD Williamson fluid in an inclined asymmetric channel through porous medium with heat transfer

    Institute of Scientific and Technical Information of China (English)

    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.

  13. Numerical simulation of peristaltic flow of a biorheological fluid with shear-dependent viscosity in a curved channel.

    Science.gov (United States)

    Ali, N; Javid, K; Sajid, M; Anwar Bég, O

    2016-01-01

    Peristaltic motion of a non-Newtonian Carreau fluid is analyzed in a curved channel under the long wavelength and low Reynolds number assumptions, as a simulation of digestive transport. The flow regime is shown to be governed by a dimensionless fourth-order, nonlinear, ordinary differential equation subject to no-slip wall boundary conditions. A well-tested finite difference method based on an iterative scheme is employed for the solution of the boundary value problem. The important phenomena of pumping and trapping associated with the peristaltic motion are investigated for various values of rheological parameters of Carreau fluid and curvature of the channel. An increase in Weissenberg number is found to generate a small eddy in the vicinity of the lower wall of the channel, which is enhanced with further increase in Weissenberg number. For shear-thinning bio-fluids (power-law rheological index, n Weissenberg number displaces the maximum velocity toward the upper wall. For shear-thickening bio-fluids, the velocity amplitude is enhanced markedly with increasing Weissenberg number.

  14. Valveless Piezoelectric Micropump Based on Coanda Effect%基于附壁效应的无阀压电泵研究

    Institute of Scientific and Technical Information of China (English)

    杨嵩; 袁寿其; 何秀华; 蔡盛川; 韦丹丹

    2014-01-01

    A valveless piezoelectric micropump applying Coanda effect has been developed.The dynamic mesh method and numerical simulation were applied for studying the fluid field and performance of micropump.The results show that due to the Coanda jet,the volume efficiency ηof the micropump was able to reach over 0.5 at zero pump pressure,which was larger than the traditional diffuser/nozzle valveless micropump.The effect of the flat cone tube and the concaved surface was discussed and the results show that the length of flat cone tube must be larger than dcot(θ/2),and when c2/c1 =1,L1/d =9,the flowrate of micropump reaches a maximum at zero pump pressure.And the comparison of η with the different c2/c1 and pump pressures shows the large width of the concaved surface could enhance the performance of micropump at a high pump pressure,but reduce the performance of micropump at a low pump pressure.Response surface methodology was utilized to optimize the structural parameters.When the pump pressure was 5 kPa,the recommend region was 4≤L1/d≤5 and 0.75 ≤c2/c1 ≤0.85.When L1/d =4.3 and c2/c1 =0.80,the maximum volume efficiency was 0.323 and the difference was 1.89% comparing with the value of simulation which was 0.317.%提出一种基于附壁效应的无阀压电泵,该泵利用附壁射流元件造成吸入过程和排出过程中进出口的流量差,实现流体输送.首先通过动网格技术及数值模拟研究微泵的内部流场和外特性,结果表明该无阀压电泵的容积效率η可以达到0.5以上,高于传统扩散/收缩管无阀压电泵.然后讨论了平面锥管长度和两分流直管间凹劈面宽度对微泵性能的影响,平面锥管长度L1必须大于d cot(θ/2),当c2/c1=1时L1/d=9的微泵在零输出压力下流量最大;不同输出压力和c2/c1的微泵流量对比表明凹劈面宽度越宽微泵输出压力性能越佳,但是在低输出压力下微泵随着凹劈面宽度的增加其容积效率降低.最后应用响应面

  15. A computer-controlled system to simulate conditions of the large intestine with peristaltic mixing, water absorption and absorption of fermentation products

    NARCIS (Netherlands)

    Minekus, M.; Smeets-Peeters, M.; Havenaar, R.; Bernalier, A.; Fonty, G.; Marol-Bonnin, S.; Alric, M.; Marteau, P.; Huis Veld, J.H.J. in 't

    1999-01-01

    This paper introduces a new type of system to simulate conditions in the large intestine. This system combines removal of metabolites and water with peristaltic mixing to obtain and handle physiological concentrations of microorganisms, dry matter and microbial metabolites. The system has been desig

  16. Effect of cross sectional geometry on PDMS micro peristaltic pump performance: comparison of SU-8 replica molding vs. micro injection molding.

    Science.gov (United States)

    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

  17. 基于MEMS技术的三明治结构被动阀微泵研制%Development of Sandwich Structure Micropump with Check Microvalve Based on MEMS Technology

    Institute of Scientific and Technical Information of China (English)

    耿照新; 邢冰冰; 丁仁伟

    2012-01-01

    To solve self-priming and difficulty in precisely controlling flow rate , the piezoelectric driving micropump with a sandwich structure and two check valves was fabricated by using MEMS technology. The micro-chamber, micropump membrane and valves were made from silicon, polydimethylsiloxane (PDMS) and SU-8, respectively. The working principle of gas and liquid micropumps, the performance of two different passive check valves, and the effect of structural parameters on the performance of mi-cropump were theoretically discussed in detail. Based on the comprehensive characteristics of the two kinds of micropumps, the design protocol, fabrication process and optimization of gas and liquid mi-cropumps were presented. Micropumps with different micropump chambers, different sizes of valve port, different microvalve structures were tested under different driving voltages. Experimental results illustrate that the micropump can be used to pump gas and liquid, and that the maximal flow rates of the gas and liquid micropumps reach 53. 6 mL/min and 1 280 |xL/min, respectively. The compression ratio of vol-ume, which is affected by the height of micropump chamber, is an important factor for self-priming. The micropump is characterized experimentally by the merits of simple structure, self-priming, low cost, easy fabrication and easy operation.%为解决微泵自吸困难、难以实现流速精确控制等问题,利用MEMS技术研制出具有三明治结构和两被动阀的压电驱动微泵,其中泵腔、泵膜和阀片分别由硅、聚二甲基硅氧烷(PDMS)和SU-8构成.从理论上,分别对气体和液体微泵的工作原理、被动阀性能以及结构参数对微泵工作性能的影响进行了分析.综合两类微泵特点,提出了气液两用微泵设计方案、工艺流程及其优化方案.在不同驱动电压条件下测试了具有不同形状泵腔、不同阀口尺寸和不同类型阀片结构的微泵.实验结果表明,该微泵可用于气体和

  18. Effects of flow properties on the performance of a diffuser-nozzle element of a valveless micropump

    Science.gov (United States)

    Das, Partha Kumar; Hasan, A. B. M. Toufique

    2016-07-01

    The flow behaviour and performance parameters of a diffuser-nozzle element of a valveless micropump have been investigated for different driving pressure frequencies. When a fluctuating pressure is imposed on the inlet boundary of a diffuser-nozzle element, there is a net flow in diffuser direction due to the dynamic effect. The variation of this net flow along with rectification capacity, and diffuser efficiency has been investigated for different frequencies of driving pressure. Flow behaviour and recirculation region due to dynamic effect have been studied as qualitative study. Pressure and velocity have been analyzed for quantitative analysis and for validation with results found in literature. 2-D geometry has been used in the present study. 3-D geometry has been modeled to justify the results obtained from 2-D analysis. Five different pressure frequencies ranging from 5 kHz to 50 kHz have been used to investigate their effects on the performance of diffuser-nozzle element in high frequency ranges. The net flow and performance of the nozzle-diffuser element are found to be decreasing with the increasing frequency. The performance is found to be less sensitive to frequency at high pressure range (above 30 kHz).

  19. The Influence of a Micropolar Fluid on Peristaltic Transport in an Annulus: Application of the Clot Model

    Directory of Open Access Journals (Sweden)

    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.

  20. Numerical analysis for MHD peristaltic transport of Carreau-Yasuda fluid in a curved channel with Hall effects

    Science.gov (United States)

    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.

  1. Numerical analysis for MHD peristaltic transport of Carreau–Yasuda fluid in a curved channel with Hall effects

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Influences of rotation and thermophoresis on MHD peristaltic transport of Jeffrey fluid with convective conditions and wall properties

    Science.gov (United States)

    Hayat, T.; Rafiq, M.; Ahmad, B.

    2016-07-01

    This article aims to predict the effects of convective condition and particle deposition on peristaltic transport of Jeffrey fluid in a channel. The whole system is in a rotating frame of reference. The walls of channel are taken flexible. The fluid is electrically conducting in the presence of uniform magnetic field. Non-uniform heat source/sink parameter is also considered. Mass transfer with chemical reaction is considered. Relevant equations for the problems under consideration are first modeled and then simplified using lubrication approach. Resulting equations for stream function and temperature are solved exactly whereas mass transfer equation is solved numerically. Impacts of various involved parameters appearing in the solutions are carefully analyzed.

  3. Influence of Magnetic Field on the Peristaltic Flow of a Viscous Fluid through a Finite-Length Cylindrical Tube

    Directory of Open Access Journals (Sweden)

    S. K. Pandey

    2010-01-01

    Full Text Available The paper presents an analytical investigation of the peristaltic transport of a viscous fluid under the influence of a magnetic field through a tube of finite length in a dimensionless form. The expressions of pressure gradient, volume flow rate, average volume flow rate and local wall shear stress have been obtained. The effects of the transverse magnetic field and electrical conductivity (i.e. the Hartmann number on the mechanical efficiency of a peristaltic pump have also been studied. The reflux phenomenon is also investigated. It is concluded, on the basis of the pressure distribution along the tubular length and pumping efficiency, that if the transverse magnetic field and the electric conductivity increase, the pumping machinery exerts more pressure for pushing the fluid forward. There is a linear relation between the averaged flow rate and the pressure applied across one wavelength that can restrain the flow due to peristalsis. It is found that there is a particular value of the averaged flow rate corresponding to a particular pressure that does not depend on the Hartmann number. Naming these values ‘critical values’, it is concluded that the pressure required for checking the flow increases with the Hartmann number above the critical value and decreases with it below the critical value. It is also inferred that magneto-hydrodynamic parameters make the fluid more prone to flow reversal. The conclusion applied to oesophageal swallowing reveals that normal water is easier to swallow than saline water. The latter is more prone to flow reversal. A significant difference between the propagation of the integral and non-integral number of waves along the tube is that pressure peaks are identical in the former and different in the latter cases.

  4. A microfluidic control system with re-usable micropump/valve actuator and injection moulded disposable polymer lab-on-a-slide

    DEFF Research Database (Denmark)

    Bu, Minqiang; Perch-Nielsen, Ivan R.; Yi, Sun;

    2011-01-01

    of different layers of polymer, and ultrasonic welding of TOPAS® lid to the slide. The re-usable pneumatic actuator not only simplifies the design of the lab-on-a-slide and reduces the fabrication cost, but also reduces the possibility of cross contamination during replacement of the disposable lab......A microfluidic control system consisting of micropump/valves with a re-usable pneumatic actuator and a disposable polymer lab-on-a-slide is presented. The lab-on-a-slide was fabricated using low cost methods, such as injection moulding of TOPAS® cyclic olefin copolymer (COC) slide, lamination...

  5. Low-Power, Low-Voltage Electroosmotic Actuator for an Implantable Micropumping System Intended for Drug Delivery Applications

    Science.gov (United States)

    Getpreecharsawas, Jirachai

    An electroosmotic (EO) actuator offers a low-power, low-voltage alternative in a diaphragm-based periodic displacement micropump intended for an implantable drug delivery system. The actuator utilizes an electroosmosis mechanism to transport liquid across a membrane to deflect the pumping diaphragms in a reciprocating manner. In the study, the membrane made of porous nanocrystalline silicon (pnc-Si) tens of nanometers in thickness was used as the promising EO generator with low power consumption and small package size. This ultrathin membrane provides the opportunity for electrode integration such that the very high electric field can be generated across the membrane with the applied potential under 1 volt for low flow rate applications like drug delivery. Due to such a low applied voltage, the challenge, however, imposes on the capability of generating the pumping pressure high enough to deflect the pumping diaphragms and overcome the back pressure normally encountered in the biological tissue and organ. This research identified the cause of weak pumping pressure that the electric field inside the orifice-like nanopores of the ultrathin membrane is weaker than conventional theory would predict. It no longer scales uniformly with the thickness of membrane, but with the pore length-to-diameter aspect ratio for each nanopore. To enhance the pumping performance, the pnc-Si membrane was coated with an ultrathin Nafion film. As a result, the induced concentration difference across the Nafion film generates the osmotic pressure against the back pressure allowing the EO actuator to maintain the target pumping flow rate under 1 volt.

  6. Effects of heat and mass transfer on peristaltic flow of a Bingham fluid in the presence of inclined magnetic field and channel with different wave forms

    Energy Technology Data Exchange (ETDEWEB)

    Akram, Safia, E-mail: safia_akram@yahoo.com [Department of Basic Sciences, MCS, National University of Sciences and Technology, Rawalpindi 46000 (Pakistan); Nadeem, S.; Hussain, Anwar [Department of Mathematics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2014-08-01

    In the present analysis we discussed the influence of heat and mass transfer on the peristaltic flow of a Bingham in an inclined magnetic field and channel with different wave forms. The governing two dimensional equations of momentum, heat and mass transfer are simplified under the assumptions of long wavelength and low Reynolds number approximation. The exact solutions of momentum, heat and mass transfer are calculated. Finally, graphical behaviors of various physical parameters are also discussed through the graphical behavior of pressure rise, pressure gradient, temperature concentration and stream functions. - Highlights: • Combine effects of heat and mass transfer on peristaltic flow problem is discussed. • Effects of inclined magnetic field and channel on new fluid model are discussed. • Effects of different wave forms are also discussed in the present flow problem.

  7. Peristaltic Motion of Non-Newtonian Fluid with Heat and Mass Transfer through a Porous Medium in Channel under Uniform Magnetic Field

    OpenAIRE

    Eldabe, Nabil T. M.; Bothaina M. Agoor; Heba Alame

    2014-01-01

    This paper is devoted to the study of the peristaltic motion of non-Newtonian fluid with heat and mass transfer through a porous medium in the channel under the effect of magnetic field. A modified Casson non-Newtonian constitutive model is employed for the transport fluid. A perturbation series’ method of solution of the stream function is discussed. The effects of various parameters of interest such as the magnetic parameter, Casson parameter, and permeability parameter on the velocity, pre...

  8. Numerical solutions of peristaltic flow of a Newtonian fluid under the effects of magnetic field and heat transfer in a porous concentric tubes

    Energy Technology Data Exchange (ETDEWEB)

    Nadeem, Sohail; Akbar, Noreen Sher; Malik, Muhammad Yousaf [Dept. of Mathematics, Quaid-i-Azam Univ., Islamabad (Pakistan)

    2010-05-15

    In the present article, we have studied the effects of heat transfer on a peristaltic flow of a magnetohydrodynamic (MHD) Newtonian fluid in a porous concentric horizontal tube (an application of an endoscope). The problem under consideration is formulated under the assumptions of long wave-length and neglecting the wave number. A closed form of Adomian solutions and numerical solutions are presented which show a complete agreement with each other. The influence of pertinent parameters is analyzed through graphs. (orig.)

  9. Activation of the umami taste receptor (T1R1/T1R3) initiates the peristaltic reflex and pellet propulsion in the distal colon

    OpenAIRE

    Kendig, Derek M; Hurst, Norman R.; Bradley, Zachary L.; Mahavadi, Sunila; Kuemmerle, John F.; Lyall, Vijay; DeSimone, John; Murthy, Karnam S.; John R Grider

    2014-01-01

    Intraluminal nutrients in the gut affect the peristaltic reflex, although the mechanism is not well defined. Recent evidence supports the presence of taste receptors and their signaling components in enteroendocrine cells, although their function is unclear. This study aimed to determine if nutrients modify colonic motility through activation of taste receptors. Colonic sections were immunostained for the umami taste receptor T1R1/T1R3, which mediates the response to umami ligands, such as mo...

  10. 磁流体微泵研究进展及其关键问题%Research Progress on MHD Micro-Pump and its Key Problems

    Institute of Scientific and Technical Information of China (English)

    赵凌志; 李建; 彭燕

    2011-01-01

    Magnetohydrodynamics (MHD) micro-pump offers an elegant means to drive and control bio-micro-fluid flow without a need for mechanical components. In this paper, we present the theory, describe typical prototypes of AC MHD and DC MHD micro-pumps, and discuss the key problems, such as electrochemical reaction, magnetohydrodynamics under micro-and nano-scale, micro-processing technology and materials of MHD micro-pumps.%磁流体(magnetohydrodynamics,MHD)微泵没有机械部件,但能够产生连续的流动,是当前电磁生物的研究热点之一.本文在详细阐述MHD微泵的工作原理、介绍交流磁流体(AC MHD)微泵和直流磁流体(DC MHD)微泵典型样机的基础上,着重分析了MHD微泵的电化学反应、微尺度下的电磁流体动力学以及微加工技术和材料等关键科学技术问题.

  11. Design and fabrication process of a micropump using bulk Pb(Zr,Ti)O 3 for microfluidic devices

    Science.gov (United States)

    Sakamoto, Ryohei; Dau, Van Thanh; Dao, Dzung Viet; Tanaka, Katsuhiko; Sugiyama, Susumu

    2007-12-01

    This paper reports on the design and simulation of a new valve-less pump for use in microfluidic applications. The simple-structure micropump comprises a piezoelectric Pb(Zr,Ti)O 3 (PZT) - Si diaphragm and flow channels which are fabricated using silicon micromachining techniques. The silicon diaphragm (5×5×0.05mm 3) is driven by the PZT (45-μm thick) actuator that has quick response time and large driving force with low power consumption. A key technology to realize the pump diaphragm is the PZT-Si bonding process using a thin gold film as an intermediate layer. Under fabrication conditions of 550°C and 0.8 MPa, the strength of the bonding was experimentally validated to be 13 MPa. The maximum displacement of the diaphragm was measured to be 3 μm 0-P with driving voltage of 30 V p-p at resonance frequency of 10 kHz. Structural analysis of the diaphragm was done in terms of three-dimensional model using commercial software ANSYS. The flow channels are easily fabricated by silicon etching process. Design of flow channels focused on a cross junction formed by neck of the pump chamber, one outlet and two opposite inlet channels. This structure allows a difference in fluidic resistance and fluidic momentum to be created inside the channels during each pump vibration cycle. Two designs of the devices which have different channel depths, namely type A and type B, was investigated. Flow simulation was done by numerical transient model (using ANSYS-Fluent), in which only the measured deformation of the PZT diagram is applied and therefore no other assumptions are required. The results showed that the mass flow rate of the type A is 0.129×10 -6 kg/s (mean flow rate of 6.3 ml/min) and that of type B is 1.65×10 -6 kg/s (mean flow rate of 80.8 ml/min).

  12. Effects of Slip Condition, Variable Viscosity and Inclined Magnetic Field on the Peristaltic Motion of a Non-Newtonian Fluid in an Inclined Asymmetric Channel

    Directory of Open Access Journals (Sweden)

    A. Afsar Khan

    2016-01-01

    Full Text Available The peristaltic motion of a third order fluid due to asymmetric waves propagating on the sidewalls of a inclined asymmetric channel is discussed. The key features of the problem includes longwavelength and low-Reynolds number assumptions. A mathematical analysis has been carried out to investigate the effect of slip condition, variable viscosity and magnetohydrodynamics (MHD. Followed by the nondimensionalization of the nonlinear governing equations along with the nonlinear boundary conditions, a perturbation analysis is made. For the validity of the approximate solution, a numerical solution is obtained using the iterative collocation technique.

  13. Peristaltic Motion of Non-Newtonian Fluid with Heat and Mass Transfer through a Porous Medium in Channel under Uniform Magnetic Field

    Directory of Open Access Journals (Sweden)

    Nabil T. M. Eldabe

    2014-01-01

    Full Text Available This paper is devoted to the study of the peristaltic motion of non-Newtonian fluid with heat and mass transfer through a porous medium in the channel under the effect of magnetic field. A modified Casson non-Newtonian constitutive model is employed for the transport fluid. A perturbation series’ method of solution of the stream function is discussed. The effects of various parameters of interest such as the magnetic parameter, Casson parameter, and permeability parameter on the velocity, pressure rise, temperature, and concentration are discussed and illustrated graphically through a set of figures.

  14. Hall and radial magnetic field effects on radiative peristaltic flow of Carreau-Yasuda fluid in a channel with convective heat and mass transfer

    Science.gov (United States)

    Hayat, T.; Farooq, S.; Alsaedi, A.; Ahmad, B.

    2016-08-01

    The purpose of present investigation is to study the Hall and MHD effects on peristaltic flow of Carreau-Yasuda fluid in a convectively curved configuration. Thermal radiation, Soret and Dufour effects are also accounted. The channel walls comprised the no slip and compliant properties. Constitutive equations for mass, momentum, energy and concentration are first modeled in view of considered assumptions and then simplified under long wavelength and low Reynolds number approximation. Solution of the resulting system of equations is carried out via a regular perturbation technique. Physical behaviors of velocity, temperature, concentration and streamlines are discussed with the help of graphical representation.

  15. Simultaneous effects of radial magnetic field and wall properties on peristaltic flow of Carreau-Yasuda fluid in curved flow configuration

    Directory of Open Access Journals (Sweden)

    T. Hayat

    2015-12-01

    Full Text Available The objective of present article is to address the magnetohydrodynamic (MHD peristaltic flow of Carreau-Yasuda fluid in a curved geometry. The channel boundaries satisfy wall slip and compliant properties. The fluid is electrically conducting through an applied magnetic field in the radial direction. Heat transfer is also studied. Governing equation comprised the viscous dissipation effects. The non-linear expressions are first obtained and then approximated using long wavelength and low Reynolds number considerations. The resulting systems are solved for the series solutions. The expressions of velocity, temperature, heat transfer coefficient and stream function are obtained and analyzed via graphical illustrations.

  16. Effects of Heat and Mass Transfer on MHD Peristaltic Flow of a Non-Newtonian Fluid through a Porous Medium between Two Coaxial Cylinders

    Directory of Open Access Journals (Sweden)

    Abeer A. Shaaban

    2013-01-01

    Full Text Available We investigated the influence of heat and mass transfer on the peristaltic flow of magnetohydrodynamic Eyring-Powell fluid under low Reynolds number and long-wavelength approximation. The fluid flows between two infinite cylinders; the inner tube is uniform, rigid, and rest, while the outer flexible tube has a sinusoidal wave traveling down its wall. The governing equations are solved numerically using finite-difference technique. The velocity, temperature, and concentration distribution are obtained. The features of flow characteristics are analyzed by plotting graphs and discussed in detail.

  17. Simultaneous effects of radial magnetic field and wall properties on peristaltic flow of Carreau-Yasuda fluid in curved flow configuration

    Science.gov (United States)

    Hayat, T.; Tanveer, A.; Alsaadi, F.

    2015-12-01

    The objective of present article is to address the magnetohydrodynamic (MHD) peristaltic flow of Carreau-Yasuda fluid in a curved geometry. The channel boundaries satisfy wall slip and compliant properties. The fluid is electrically conducting through an applied magnetic field in the radial direction. Heat transfer is also studied. Governing equation comprised the viscous dissipation effects. The non-linear expressions are first obtained and then approximated using long wavelength and low Reynolds number considerations. The resulting systems are solved for the series solutions. The expressions of velocity, temperature, heat transfer coefficient and stream function are obtained and analyzed via graphical illustrations.

  18. Influence of induced magnetic field and heat transfer on the peristaltic motion of a Jeffrey fluid in an asymmetric channel: Closed form solutions

    Energy Technology Data Exchange (ETDEWEB)

    Akram, Safia, E-mail: safia_akram@yahoo.com [Department of Humanities and Basic Sciences, Military College of Signals, National University of Sciences and Technology, Rawalpindi 46000 (Pakistan); Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000 (Pakistan); Nadeem, S. [Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000 (Pakistan)

    2013-02-15

    We discuss the peristaltic motion of a two dimensional Jeffrey fluid in an asymmetric channel under the effects of induced magnetic field and heat transfer. The problem is simplified by using long wave length and low Reynolds approximations. Exact and closed form Adomian solutions are presented. Expressions for the velocity, stream function, magnetic force function, temperature, pressure gradient and pressure rise are computed. The results of pertinent parameters are discussed. Finally, the trapping phenomena for different wave shapes are discussed. It is observed that the pressure rise for sinusoidal wave is less than trapezoidal wave and greater than triangular in a Jeffrey fluid. - Highlights: Black-Right-Pointing-Pointer The effects of induced magnetic field and heat transfer in peristaltic motion of a two dimensional Jeffrey fluid are discussed. Black-Right-Pointing-Pointer In this paper exact and closed form Adomian solutions are presented. Black-Right-Pointing-Pointer Different wave shapes are considered to observe the behavior of pressure rise and trapping phenomena.

  19. Influence of heat and mass transfer, initial stress and radially varying magnetic field on the peristaltic flow in an annulus with gravity field

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Alla, A.M., E-mail: mohmrr@yahoo.com [Mathematics Department, Faculty of Science, Taif University 888 (Saudi Arabia); Mathematics Department, Faculty of Science, Sohag (Egypt); Abo-Dahab, S.M. [Mathematics Department, Faculty of Science, Taif University 888 (Saudi Arabia); Mathematics Department, Faculty of Science, SVU, Qena 83523 (Egypt); El-Shahrany, H.D. [Mathematics Department, Faculty of Science, Taif University 888 (Saudi Arabia)

    2014-08-01

    In this paper, the effects of both initial stress, radially varying and gravity field on the peristaltic flow of an incompressible MHD Newtonian fluid in a vertical annulus have been studied under the assumption of long wavelength and low-Reynolds number. The analytical solution has been derived for the temperature, concentration and velocity. The results for velocity, concentration and temperature obtained in the analytical form have been evaluated numerically and discussed briefly. The effect of the non-dimensional wave amplitude, the coefficient of viscosity, Sort number, Schmidt number, initial stress, gravitational field and the dimensionless time-mean flow in the wave frame are analyzed theoretically and computed numerically. The expressions for pressure rise, temperature, concentration field, velocity and pressure gradient are sketched for various embedded parameters and interpreted. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of initial stress and gravitational field. - Highlights: • Initial stress, radially varying and gravity field on the peristaltic flow of MHD Newtonian fluid. • The analytical solution for the temperature, concentration and velocity. • Effect of wave amplitude, viscosity, Sort number, Schmidt number, initial stress, gravitational in the wave frame.

  20. Peristaltic propulsion of generalized Burgers' fluids through a non-uniform porous medium: a study of chyme dynamics through the diseased intestine.

    Science.gov (United States)

    Tripathi, D; Anwar Bég, O

    2014-02-01

    A mathematical study of the peristaltic flow of complex rheological viscoelastic fluids using the generalized fractional Burgers' model through a non-uniform channel is presented. This model is designed to study the movement of chyme and undigested chyme (biophysical waste materials) through the small intestine to the large intestine. To simulate blockages and impedance of debris generated by cell shedding, infections, adhesions on the wall and undigested material, a drag force porous media model is utilized. This effectively mimicks resistance to chyme percolation generated by solid matrix particles in the regime. The conduit geometry is mathematically simulated as a sinusoidal propagation with linear increment in shape of the bolus along the length of channel. A modified Darcy-Brinkman model is employed to simulate the generalized flows through isotropic, homogenous porous media, a simplified but physically robust approximation to actual clinical situations. To model the rheological properties of chyme, a viscoelastic Burgers' fluid formulation is adopted. The governing equations are simplified by assuming long wavelength and low Reynolds number approximations. Numerical and approximate analytical solutions are obtained with two semi-numerical techniques, namely the homotopy perturbation method and the variational iteration method. Visualization of the results is achieved with Mathematica software. The influence of the dominant hydromechanical and geometric parameters such as fractional viscoelastic parameters, wave number, non-uniformity constant, permeability parameter, and material constants on the peristaltic flow characteristics are depicted graphically. PMID:24300568

  1. Experimental verification of an equivalent circuit for the characterization of electrothermal micropumps: high pumping velocities induced by the external inductance at driving voltages below 5 V.

    Science.gov (United States)

    Stubbe, Marco; Gyurova, Anna; Gimsa, Jan

    2013-02-01

    Electrothermal micropumps (ETμPs) use local heating to create conductivity and permittivity gradients in the pump medium. In the presence of such gradients, an external AC electric field influences smeared spatial charges in the bulk of the medium. When there is also a symmetry break, the field-charge interaction results in an effective volumetric force resulting in medium pumping. The advantages of the ETμP principle are the absence of moving parts, the opportunity to passivate all the pump structures, homogeneous pump-channel cross-sections, as well as force plateaus in broad frequency ranges. The ETμPs consisted of a DC-heating element and AC field electrodes arranged in a 1000 μm × 250 μm × 60 μm (length × width × height) channel. They were processed as platinum structures on glass carriers. An equivalent-circuit diagram allowed us to model the frequency-dependent pumping velocities of passivated and nonpassivated ETμPs, which were measured at medium conductivities up to 1.0 S/m in the 300 kHz to 52 MHz frequency range. The temperature distributions within the pumps were controlled by thermochromic beads. Under resonance conditions, an additional inductance induced a tenfold pump-velocity increase to more than 50 μm/s at driving voltages of 5 V(rms). A further miniaturization of the pumps is viewed as quite feasible.

  2. Optimal Design and Operation for a No-Moving-Parts-Valve (NMPV Micro-Pump with a Diffuser Width of 500 µm

    Directory of Open Access Journals (Sweden)

    Jia-Ming Sun

    2009-05-01

    Full Text Available A no-moving-parts-valve (NMPV with a diffuser width of D = 500 microns was investigated in this study by numerical simulations at Reynolds numbers, ReD, ranging from 20 to 75, and expansion valve angles ranging from 30° < θ1 < 57° and 110° < θ2 < 120°. The D p,i value, 1.02 < D p,i < 1.14, is larger within the proposed range of the expansion valve angles. A flow channel structure with a depth of 500 micron is manufactured using yellow light lithography in this study. From prior analyses and experiments, it is found that piezoelectric films work better at a buzz driving frequency of f < 30Hz and the best operating frequency is at a driving frequency of f = 10Hz because it produces the largest net flow. In addition, the expansion angles θ1 = 30° and θ2 = 120° are the best expansion angles because they produce the largest net flow. These related results are very helpful for the actual design of no-moving-parts-valve micro-pump.

  3. Influence of heat and mass transfer, initial stress and radially varying magnetic field on the peristaltic flow in an annulus with gravity field

    Science.gov (United States)

    Abd-Alla, A. M.; Abo-Dahab, S. M.; El-Shahrany, H. D.

    2014-08-01

    In this paper, the effects of both initial stress, radially varying and gravity field on the peristaltic flow of an incompressible MHD Newtonian fluid in a vertical annulus have been studied under the assumption of long wavelength and low-Reynolds number. The analytical solution has been derived for the temperature, concentration and velocity. The results for velocity, concentration and temperature obtained in the analytical form have been evaluated numerically and discussed briefly. The effect of the non-dimensional wave amplitude, the coefficient of viscosity, Sort number, Schmidt number, initial stress, gravitational field and the dimensionless time-mean flow in the wave frame are analyzed theoretically and computed numerically. The expressions for pressure rise, temperature, concentration field, velocity and pressure gradient are sketched for various embedded parameters and interpreted. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of initial stress and gravitational field.

  4. Thermal and velocity slip effects on the MHD peristaltic flow with carbon nanotubes in an asymmetric channel: application of radiation therapy

    Science.gov (United States)

    Akbar, Noreen Sher; Nadeem, S.; Khan, Zafar Hayat

    2014-10-01

    Peristaltic flow is used to study the flow and heat transfer of carbon nanotubes in an asymmetric channel with thermal and velocity slip effects. Two types of carbon nanotubes, namely, single- and multi-wall carbon nanotubes are utilized to see the analysis with water as base fluids. Empirical correlations are used for the thermo-physical properties of carbon nanotubes (CNTs) in terms of solid volume fraction of CNTs. The governing equations are simplified using long wavelength and low Reynolds number approximation. Exact solutions have been evaluated for velocity, pressure gradient, the solid volume fraction of CNTs and temperature profile. The effects of various flow parameters, i.e. Hatmann number M, the solid volume fraction of the nanoparticles ϕ, Grashof number G, velocity slip parameter β, thermal slip parameter γ and Prandtl number P r are presented graphically for both single- (SWCNT) and multi-wall carbon nanotubes (MWCNT).

  5. Peristaltic Flow and Heat Transfer of a Conducting Phan-Thien-Tanner Fluid in an Asymmetric Channel - Application to Chyme Movement in Small Intestine

    Science.gov (United States)

    Vajravelu, K.; Sreenadh, S.; Dhananjaya, S.; Lakshminarayana, P.

    2016-08-01

    In this paper, the influence of heat transfer on the peristaltic flow of a conducting Phan-Thien-Tanner fluid in an asymmetric channel with porous medium is studied. The coupled nonlinear governing differential equations are solved by a perturbation technique. The expressions for the temperature field, the stream function, the axial velocity, and the pressure gradient are obtained. The effects of the various physical parameters such as the magnetic parameter M, the permeability parameter σ, the Brinkman number Br and the Weissenberg number We on the pumping phenomenon are analyzed through graphs and the results are discussed in detail. It is observed that the velocity and the pressure are decreased with increasing the magnetic parameter M whereas the effect of the parameter M on the temperature field is quite the opposite.

  6. Microvalves and Micropumps for BioMEMS—Introduction to BioMEMS By Albert Folch, University of Washington, Seattle, USA CRC Press: Boca Raton, FL, USA; Price: $89.95 ISBN: 9781439818398; ISBN 10: 1439818398 Publication Date: 26 March 2012; Number of Pages: 400 Binding(s: Hardback

    Directory of Open Access Journals (Sweden)

    Anthony K. Au

    2011-05-01

    Full Text Available This review presents an extensive overview of a large number of microvalve and micropump designs with great variability in performance and operation. The performance of a given design varies greatly depending on the particular assembly procedure and there is no standardized performance test against which all microvalves and micropumps can be compared. We present the designs with a historical perspective and provide insight into their advantages and limitations for biomedical uses. (Note: This review has been adapted from a chapter from the upcoming textbook by Albert Folch, Introduction to BioMEMS, published by CRC Press.

  7. The clinical monitoring and nursing of micro-pump potassium after surgery operation%外科术后微量泵经静脉补钾的临床监测及护理

    Institute of Scientific and Technical Information of China (English)

    李娟; 李勇兰; 党翠云; 曾小平

    2008-01-01

    To summarize the experience of clinical monitoring and nursing in patients who used the micro-pump potassium to rectify the hypokalemia after operation in ICU,heart surgery and common surgery department of our hospital.76 cases of hypokalemia were selected and used micro-pump to rectify the hypokalemia after surgery operation by intravenous infusion 10% liquids with original potassium chloride,the process was monitored and nursed closely.This prevented the occurrence of hypokalemia after operation effectively.During pumping potassium period,there was no phlebitis,no arrhythmia or other adverse effect occurred.Using micro-pump to supply potassium by vein to correct hypokalemia under tight clinical monitoring and nursing is effective and safe.%总结我院ICU、心脏外科、普外科病人术后使用微量泵泵钾纠正低钾血症的临床监测及护理体会.76例外科术后低钾血症患者使用微量注射泵经静脉输注浓度为10%氯化钾原液,以纠正低钾血症,补钾过程中进行严密监测和护理.有效预防了术后低血钾的发生.患者在泵钾期间无1例高钾血症发生,无静脉炎、心律失常等不良反应发生.严密的临床监测和护理下使用微量泵经静脉补钾纠正低钾血症的方法 是有效、安全的.

  8. Design and research of micro-pump based on photo-induced bending material%基于光致弯曲材料的微泵设计研究

    Institute of Scientific and Technical Information of China (English)

    朱玉田; 许溱; 陈茂林; 刘钊; 俞燕蕾

    2011-01-01

    Based on a photo-induced bending material which has two-way shape memory function,a novel micro-pump with valves was designed and made.Combined with material deformation principle,the micro-pump's finite element model was built by using the finite element software ANSYS,and the pumping capacity calculated by ANSYS was gained and compared with the one came from the pump prototype's experimental results,then the consistency of which validates this micro-pump design's rationality.The material application on micro-pump has some reference values for relative engineering application and the photo-induced bending effect equivalent also provides research methods for similar problems.%基于一种具有双向形状记忆功能的光致弯曲材料,设计了新型有阀微泵结构并制作了样机。结合材料的光致弯曲效应等效理论,采用ANSYS软件建立了微泵空腔结构的几何模型,并对所建模型的泵水体积进行了计算求解。对样机进行实验得到了微泵的实际泵水性能,将其与理论计算结果进行对比,得出两者基本一致的结论,从而验证了微泵结构设计的合理性。光致弯曲材料在微泵上的应用形式,对相关工程应用有一定的参考价值,光致效应的等效也为解决相关问题提供了研究方法。

  9. Efficacy of intravenous injection of urapidil by micro-pump in treatment of hypertensive emergency patients%经微量泵静脉注射乌拉地尔治疗高血压急症疗效观察

    Institute of Scientific and Technical Information of China (English)

    庄小静; 周朝虹

    2009-01-01

    目的 探讨乌拉地尔微量泵静脉注射治疗高血压急症的疗效和安全性.方法 对78例高血压急症患者用乌拉地尔50mg加入40ml液体中静脉微泵输注,监测并记录用药前及用药后5、10、30、60、120min血压(BP)、心率(HR)、伴随症状及不良反应.结果 应用乌拉地尔后各时段BP较用药前均明显下降,差异有统计学意义(P<0.05),而HR则无明显变化.结论 乌拉地尔微量泵静脉注射治疗高血压急症,疗效确切,不良反应少.%Objective To investigate the efficacy and safety of urapidil intravenous injected by micro-pump in treatment of hypertensive emergency patients. Methods There 78 cases with hypertensive, emergency werereated wih 50rag urapidil by intravenous micro-pump. The blood pressure (BP),heart rate (HR),adverse reactions were monitored and recorded before administration and 5min,10min,30min,60min,120min after administration. Results Compared to that before administration,blood pressure were significantly decreased after administration, showing a significant difference. While there was no significant difference in the heart rate. Conclusion Urapidil intravenous injected by micro-pump is effective for treatment of hypertensive emergency with fewer adverse reactions.

  10. Sewer Cleaning Inspection Robot Based on Peristaltic Walking%蠕动式污水管道清淤机器人

    Institute of Scientific and Technical Information of China (English)

    曹建树; 徐宝东; 鲁军; 刘强; 张义; 黄子茂

    2014-01-01

    采用模块化方法对污水管道清淤机器人中的管道清理单元、推进舱、阀组和控制单元等模块加以组合,并对其进行了总体方案设计,给出了机器人蠕动行走液压油路方案,分析了其蠕动行走过程。介绍了系统上、下位机联合控制方案,同时描述了下位机在控制系统中的功能及其对应程序流程。在此基础上,研制了一台污水管道清淤机器人,并对其进行了实验。结果表明:该机器人在现有方案下能够实现预定的设计目标,管道清理检测质量良好,可降低工人工作强度。%By combining pipe cleaning unit,propulsion module,valves and control with modularization method,the general scheme of a novel sewer cleaning inspection robot was designed. The peristaltic walking program based on hydraulic oil circuit of the ro-bot was given,and its peristaltic walking processes were analyzed. United control scheme of the system between host and lower comput-er was introduced. At the same time,the lower computer function in control system and its corresponding program flow were described. Upon this basis,a sewer cleaning inspection robot was developed and it was verified by testing experiments. The results show that the performances of robot have a good agreement with design aim in the scheme,and inspecting effect is good,which can reduce strength of worker.

  11. Influence of Heat Source, Thermal Radiation and Inclined Magnetic Field on Peristaltic Flow of a Hyperbolic Tangent Nanofluid in a Tapered Asymmetric Channel.

    Science.gov (United States)

    Kothandapani, Munirathinam; Prakash, Jayavel

    2014-10-31

    In the present analytic thinking, we have modeled the governing equations of a two dimensional peristaltic transport of a Hyperbolic tangent nanofluid in the presence of a heat source/sink with the combined effects of thermal radiation and inclined magnetic field in a tapered asymmetric channel. The propagation of waves on the non-uniform walls to have different amplitudes and phase but the same wave speed is produced the tapered asymmetric channel. The equations of dimensionless temperature and nanoparticle concentration are solved analytically under assumptions of long wavelength and low Reynolds number. The governing equations of momentum of a hyperbolic tangent nanofluid for the tapered asymmetric channel have also been solved analytically using the regular perturbation method. The expression for average rise in pressure has been figured using numerical integrations. The effects of various physical parameters entering into the problem are discussed numerically and graphically. The phenomenon of trapping is also investigated. Furthermore, the received results show that the maximum pressure rise gets increased in case of non-Newtonian fluid when equated with Newtonian fluid. PMID:25373110

  12. Effects of rotation and magnetic field on the nonlinear peristaltic flow of a second-order fluid in an asymmetric channel through a porous medium

    Institute of Scientific and Technical Information of China (English)

    A.M.Abd-Alla; S.M.Abo-Dahab; H.D.El-Shahrany

    2013-01-01

    In this paper,the effects of both rotation and magnetic field of the peristaltic transport of a second-order fluid through a porous medium in a channel are studied analytically and computed numerically.The material is represented by the constitutive equations for a second-order fluid.Closed-form solutions under the consideration of long wavelength and low Reynolds number is presented.The analytical expressions for the pressure gradient,pressure rise,friction force,stream function,shear stress,and velocity are obtained in the physical domain.The effects of the non-dimensional wave amplitude,porosity,magnetic field,rotation,and the dimensionless time-mean flow in the wave frame are analyzed theoretically and computed numerically.Numerical results are given and illustrated graphically in each case considered.Comparison was made with the results obtained in the presence and absence of rotation,magnetic field,and porosity.The results indicate that the effects of the non-dimensional wave amplitude,porosity,magnetic field,rotation,and the dimensionless time-mean flow are very pronounced in the phenomena.

  13. Comparison of a pulsatile blood pump and a peristaltic roller pump during hemoperfusion treatment in a canine model of paraquat poisoning.

    Science.gov (United States)

    Lee, Jung Chan; Park, Chan Young; Choi, Seong Wook; Kim, Jeong Chul; Lim, Ki Moo; Kim, Kyuseok; Jung, Sung Koo; Kwak, Young Ho; Shin, Sang Do; Jo, Ik Joon; Suh, Gil Joon; Min, Byoung Goo

    2008-07-01

    This study examined the treatment efficacy and the damage to the blood during hemoperfusion for treating paraquat poisoning using two blood pump mechanisms. Paraquat-poisoned animal models were prepared. A conventional hemodialysis machine, AK90, with a peristaltic roller pump and a cardiopulmonary support system, T-PLS, with a pulsatile blood pump were used during the animal experiments. A total of 12 dogs were treated with hemoperfusion using a charcoal column. Six dogs were treated with hemoperfusion and T-PLS, and the other six were treated with AK90. A paraquat dose of 30 mg/kg was administrated by an intravenous injection. Both pumps maintained blood flow rates of 125 mL/min measured by an ultrasonic flowmeter. For anticoagulation, heparin was administrated by an initial bolus (250 IU/kg) and a continuous injection (100 IU/kg/h). During the experiments, T-PLS and AK90 showed a similar toxin removal efficacy. Both devices decreased the plasma paraquat concentration to 10% of the initial dose within 4-h hemoperfusion. The two pumps showed similar hemolysis properties with acceptable levels. Although T-PLS was developed as a cardiopulmonary bypass system, it can also be used as a hemoperfusion treatment device. PMID:18638308

  14. Cineradiography of the liquid bolus swallow. A study of the speed ot the bolus and peristaltic wave and of movement of the hyoid bone, larynx, and epiglottis

    International Nuclear Information System (INIS)

    In the evaluation of the dysphagic patient, radiology is crucial as a technique for monitoring morphology and function. In particular, high-speed cineradiography can reveal a variety of pharyngeal dysfunctions. However, in the literature and in practice the difference between normal and abnormal function is not always clear. This monography is based on high-speed cineradiographies of swallowing in 75 non-dysphagic volunteers and in 189 dysphagic patients. The purpose was to study whether differences in bolus volumes, patient position, age and gender had any effects on the following parameters: the speed of the peristaltic wave and apex of the liquid barium bolus, the length of movement and the movement pattern of the hyoid bone and larynx, and epiglottic function. The study disclosed that the speed of the bolus, the anterior-superior movement and net movement of the hyoid bone increased significantly with larger bolus volumes. The position of the individual in relation to gravity significantly influenced the speed of peristalsis. In most of the measured parameters there were no differences between non-dysphagic and dysphagic individuals expect for differences in the intrapersonal variations and in the anterior-superior movement of the hyoid bone. In patients with pharyngeal dysfunction the initial stage of the elevation of the larynx was significantly lower than in patients without dysfunction. The approximation of the thyroid cartilage to the hyoid bone was significantly greater in individuals with normal epiglottic function than in those with epiglottic dysmobility. It is suggested that abnormal speed of peristalsis may be a mild form of dysfunction. Measurements of the aforementioned speed and movements can be done if bolus volume, age and position of the patient, film speed and magnifications factors are known. Hypotheses concerning epiglottic function and central control of swallowing are proposed. (au)

  15. A New Concept of a Drug Delivery System with Improved Precision and Patient Safety Features

    OpenAIRE

    Florian Thoma; Frank Goldschmidtböing; Peter Woias

    2014-01-01

    This paper presents a novel dosing concept for drug delivery based on a peristaltic piezo-electrically actuated micro membrane pump. The design of the silicon micropump itself is straight-forward, using two piezoelectrically actuated membrane valves as inlet and outlet, and a pump chamber with a piezoelectrically actuated pump membrane in-between. To achieve a precise dosing, this micropump is used to fill a metering unit placed at its outlet. In the final design this metering unit will be ma...

  16. 一种低成本压电无阀微泵的研制%Research and fabrication of a low-cost valveless micropump based on piezoelectric actuation*

    Institute of Scientific and Technical Information of China (English)

    徐亮; 应济; 李俊

    2011-01-01

    提出了一种低成本的由压电材料驱动的平面扩张/收缩管无阀微泵的制作工艺.通过数值模拟确定了扩张/收缩管扩张角的最优值,在此基础上,采用光刻和湿法刻蚀工艺,刻蚀了300μm深的泵腔基片和100 μm深的盖片;使用等离子体清洗技术将其与PDMS薄膜键合,完成了可以实现单向泵送的压电无阀微泵样机制作.研究了该压电无阀微泵样机的性能,分别分析了压电振子的激励频率、电压和微泵背压对其流量的影响.实验结果表明:在100V,110Hz交流方波电压信号的作用下,微泵有最大输出流量为436μL/min,最大背压为620 Pa.%A low-cost valveless micropump based on piezoelectric actuation is presented. The optimized value of opening angle is obtained by numerical simulation, which is the reference of design parameters of the diffuser/ nozzle element. A 300 μm depth of pump chamber substrate and a 100 μm depth of cover are fabricated on pyrex glass using photographic and wet chemical etching processes. Then, by using plasma cleaning technology, they are bonded to PDMS membrane to accomplish the fabrication of the micropump. The maximum flow rate and baekpressure of the pump are about 436 μL/min and 620 Pa when applying a 100V square wave driving voltage at 110 Hz across the piezoelectric-disc.

  17. 流变学流体的蠕动传输:食道中食物块的运动模型%Peristaltic Transport of a Rheological Fluid:Model for Movement of Food Bolus Through Esophagus

    Institute of Scientific and Technical Information of China (English)

    J·C·密斯拉; S·麦蒂; 海治

    2012-01-01

    研究食道中蠕动传输的流体力学.对任意的波形和任意的管道长度,建立起流变学流体蠕动传输的数学模型.用粘性流体的Ostwald-de Waele幂定律,描述非Newton流体的流动特性.解析公式化模型,详细且精确地给出食物块在食道中蠕动传输相关的一些重要性质.分析中应用了润滑理论,本研究特别适合于Reynolds数不大的情况.将食道看作环形的管道,通过食道壁周期性的收缩来传输食物块.就单个波和周期性收缩一组波的传播,研究与传输过程有关变量的变化,如压力、流速、食物颗粒轨迹以及流量等.局部压力的变化,对流变指数n有着高度的敏感性.研究结果清晰地表明,食物块在食道中蠕动传输时,Newton流体或流变学流体构成的连续流体,以组合波传播比大间隔单波传播,传输效率要高得多.%Fluid mechanical peristaltic transport through esophagus had been of concern. A mathematical model had been developed with an aim to study the peristaltic transport of a rheo-logical fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of viscous fluid was considered here to depict the non-Newtonian behaviour of the fluid. The model was formulated and analyzed with the specific aim of exploring some important information concerning the movement of food bolus through the esophagus. The analysis had been carried out by using lubrication theory. The study was particularly suitable for cases where the Reynolds number was small. The esophagus was 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 were investigated for a single wave as well as for a train of periodic peristaltic waves. Locally variable pressure was seen to be highly sensitive to the flow index n

  18. Analysis of flow characteristics in thermal-bubble actuated diffuser-nozzle valveless micropump%热汽泡驱动无阀微泵流动特性分析

    Institute of Scientific and Technical Information of China (English)

    潘良明; 岳万凤; 魏敬华; 陈德奇

    2013-01-01

    Based on the different flow resistance characteristic of diffuser/nozzle at the bubble growth and condensation stage, the flow characteristics of thermal-bubble actuated valveless micropump under different ratio of heating, driving frequency and diverging angle and different heating power are numerically investigated. Evaporation and condensation processes are accomplished by Volume of Fluid (VOF) multiphase flow model and User Defined Functions (UDF) interface. The results reveal that with the same ratio of heating time, the volume flow rate increases at first and then decreases with the increasing driving frequency. The micropump has a maximum flow rate of 5. 87 μL/min when the driving pulse is 250 Hz at 10% heating ratio. The volume flow rate increases at first then decreases with the enlarging diverging angle when keeping the aspect ratio constant, and it will reach the maximum when the diverging angle is 14°, and it has a higher pressure difference between the diffuser and the nozzle. The average velocity at the diffuser neck is always greater than the nozzle during the entire driving period, the pumping flow rate presents a trend of increasing at first and then flatting with the increasing heating power.%基于热汽泡生长和冷凝为微泵提供泵送压力源以及扩张管/收缩管流动阻力特性不同而实现差量流动的原理,对不同加热时间比例、驱动频率以及不同扩张角度及功率下热汽泡驱动无阀微泵流动特性进行了研究.蒸发和凝结过程通过流体体积函数(VOF)两相流模型及用户自定义函数(UDF)接口实现.结果表明:相同加热时间比例下,随着驱动频率增加,微泵泵送流量呈先增加后降低趋势;加热时间比例为10%,驱动频率为250 Hz时泵送流量达到最大值5.87 μL/min;在保持微泵扩张管/收缩管长宽比不变的情况下,泵送流量随扩张角也有先增后减的趋势,并在扩张角为14°时泵送流量达到最大,扩张管/收

  19. Design and Characterization of a Sensorized Microfluidic Cell-Culture System with Electro-Thermal Micro-Pumps and Sensors for Cell Adhesion, Oxygen, and pH on a Glass Chip

    Directory of Open Access Journals (Sweden)

    Sebastian M. Bonk

    2015-07-01

    Full Text Available We combined a multi-sensor glass-chip with a microfluidic channel grid for the characterization of cellular behavior. The grid was imprinted in poly-dimethyl-siloxane. Mouse-embryonal/fetal calvaria fibroblasts (MC3T3-E1 were used as a model system. Thin-film platinum (Pt sensors for respiration (amperometric oxygen electrode, acidification (potentiometric pH electrodes and cell adhesion (interdigitated-electrodes structures, IDES allowed us to monitor cell-physiological parameters as well as the cell-spreading behavior. Two on-chip electro-thermal micro-pumps (ETμPs permitted the induction of medium flow in the system, e.g., for medium mixing and drug delivery. The glass-wafer technology ensured the microscopic observability of the on-chip cell culture. Connecting Pt structures were passivated by a 1.2 μm layer of silicon nitride (Si3N4. Thin Si3N4 layers (20 nm or 60 nm were used as the sensitive material of the pH electrodes. These electrodes showed a linear behavior in the pH range from 4 to 9, with a sensitivity of up to 39 mV per pH step. The oxygen sensors were circular Pt electrodes with a sensor area of 78.5 μm2. Their sensitivity was 100 pA per 1% oxygen increase in the range from 0% to 21% oxygen (air saturated. Two different IDES geometries with 30- and 50-μm finger spacings showed comparable sensitivities in detecting the proliferation rate of MC3T3 cells. These cells were cultured for 11 days in vitro to test the biocompatibility, microfluidics and electric sensors of our system under standard laboratory conditions.

  20. 微极流体蠕动泵经由滑移边界管道输送的Stokes流动%Study on Stokes Flow of Micro-Polar Fluids by Peristaltic Pumping Through a Tube With Slip Boundary Condition

    Institute of Scientific and Technical Information of China (English)

    D·特里帕蒂; M·K·乔伯; P·K·古泊塔; 吴承平

    2011-01-01

    The Stokes flow of micro-polar fluids by peristaltic pumping through the cylindrical tube under the effect of slip boundary condition was studied. The motion of wall was governed by the sinusoidal wave equation. Analytical and numerical solutions for axial velocity, micro-polar vector, stream function, pressure gradient, friction force and mechanical efficiency were obtained by using the lubrication theory. The impacts of emerging parameters such as coupling number, micro-polar parameter and slip parameter on pumping characteristic, friction force and trapping phenomena were depicted graphically. Numerical computation infers that more pressure requires for peristaltic pumping when coupling number is large while opposite behavior is found for micro-polar parameter and the slip parameter. The size of trapped bolus reduces with coupling number and micro-polar parameter whereas it blows up with slip parameter.%计及管道边界条件滑移的影响,研究微极流体蠕动泵,经由圆柱形管道输运的Stokes流动.壁面运动的控制方程为正弦波方程.使用润滑理论,得到了轴向速度、微转动向量、流函数、压力梯度、摩擦力和机械效率的解析数值解.用图形表示出构成参数,如像耦合参数、微极参数和表征蠕流泵特性的滑移参数、摩擦力和俘获现象的影响.数值计算表明,当耦合参数较大时,需要蠕动泵的压力更大,而微极参数和滑移参数正相反.俘获团块的大小随耦合参数和微极参数的减小而缩小,而随滑移参数的增大而缩小.

  1. 双压电驱动微泵泵膜的ANSYS仿真和结构优化分析%ANSYS Simulation and Structure Optimization of Double Piezoelectric Layers Driven Micro-Pump Membrane Structure

    Institute of Scientific and Technical Information of China (English)

    邓凯; 陈可娟

    2013-01-01

    A new kind of double piezoelectric layers driven pump membrane structure is introduced and the small deflection bending deformation theory pump membrane is analyzed.Using ANSYS software to establish the finite element model of the pump membrane,the static analysis and modal analysis is done.The pump membrane structure is optimized by using orthogonal test method.The results show that piezoelectric layer thickness influenced the deformation of pump membrane the most,and the driving voltage,pump membrane radius, electrode layer thickness,and basic level thickness followed.Pump membrane radius influenced the frequency of pump membrane the most,and the piezoelectric layer thickness, electrode layer thickness and basic level thickness followed.To optimize pump membrane structure can improve the efficiency of micro-pump, and the results provide the basis for the optimal design of micro-pump.%提出了一种新型的双压电泵膜结构,分析了泵膜小挠度弯曲形变理论.运用ANSYS软件建立了泵膜的有限元模型,并对泵膜进行了电压驱动静态分析和模态分析,通过正交试验法对泵膜结构进行了优化.分析表明,压电层厚度对膜片形变影响最大,其次依次是驱动电压、泵膜半径、电极层厚度、基层厚度;泵膜半径对膜片频率影响最大,其次依次是压电层厚度、电极层厚度、基层厚度;对泵膜结构进行优化,可以提高微泵的工作效率,研究结果为微泵的优化设计提供了依据.

  2. Application of RAGAZZINI Peristaltic Pump in the Production of New-process Mixiang Baijiu(Liquor)%RAGAZZINI蠕动泵在新工艺米香型白酒生产中的应用

    Institute of Scientific and Technical Information of China (English)

    朱旭平

    2015-01-01

    新工艺米香型白酒生产线属长乐烧企业的创新项目,该项目获广东轻工科技二等奖、获国家轻工科技优秀奖。新工艺与传统工艺最大的区别在于,前者是将熟化后的原料直接加水、加曲输入发酵罐糖化、发酵同罐进行,后者是先将熟化的原料在糖化槽中糖化后加水再输入发酵罐。前者物料为液固松散分离状态,后者为糊化状态,因此常用的气动隔膜泵输送液固松散分离状态物料时就常常将液体抽走,造成管道阻塞。长乐烧酒业在新工艺生产线上利用蠕动泵实现了将熟化原料加水混合物料轻松输入发酵罐的目标,解决了管道阻塞问题,达到了连续生产目的,彻底改变了蒸饭机至发酵罐间物料自动输送的难题。%New-process Mixiang Baijiu(liquor) is the innovative program in Changle Distillery which won the 2nd Prize of Guangdong Light Industry Science and Technology and State Light Industry Science&Technology Excellent Prize. The difference between new-process produc-tion and traditional production were as follows:in the new process (raw materials in liquid&solid separation loose state), water was added di-rectly in cooked raw materials, then caky starter was added for saccharfication and fermentation in the same fermenter;in traditional process (raw materials in gelatinized state), cooked raw materials were saccharified in saccharifying tank at first, then water was added for fermentation in the fermenter. The use of new-process often induced pipe obstruction because the commonly-used pneumatic drive membrane pump drained liquid during the transportation of liquid&solid separation loose raw materials. Changle Distillery used peristaltic pump to settle such prob-lem, which could achieve continuous production and completely solve pipeline blocking from steam machine to fermenter.

  3. Application of RAGAZZINI Peristaltic Pump in the Production of New-process Mixiang Baijiu(Liquor)%RAGAZZINI蠕动泵在新工艺米香型白酒生产中的应用

    Institute of Scientific and Technical Information of China (English)

    朱旭平

    2015-01-01

    New-process Mixiang Baijiu(liquor) is the innovative program in Changle Distillery which won the 2nd Prize of Guangdong Light Industry Science and Technology and State Light Industry Science&Technology Excellent Prize. The difference between new-process produc-tion and traditional production were as follows:in the new process (raw materials in liquid&solid separation loose state), water was added di-rectly in cooked raw materials, then caky starter was added for saccharfication and fermentation in the same fermenter;in traditional process (raw materials in gelatinized state), cooked raw materials were saccharified in saccharifying tank at first, then water was added for fermentation in the fermenter. The use of new-process often induced pipe obstruction because the commonly-used pneumatic drive membrane pump drained liquid during the transportation of liquid&solid separation loose raw materials. Changle Distillery used peristaltic pump to settle such prob-lem, which could achieve continuous production and completely solve pipeline blocking from steam machine to fermenter.%新工艺米香型白酒生产线属长乐烧企业的创新项目,该项目获广东轻工科技二等奖、获国家轻工科技优秀奖。新工艺与传统工艺最大的区别在于,前者是将熟化后的原料直接加水、加曲输入发酵罐糖化、发酵同罐进行,后者是先将熟化的原料在糖化槽中糖化后加水再输入发酵罐。前者物料为液固松散分离状态,后者为糊化状态,因此常用的气动隔膜泵输送液固松散分离状态物料时就常常将液体抽走,造成管道阻塞。长乐烧酒业在新工艺生产线上利用蠕动泵实现了将熟化原料加水混合物料轻松输入发酵罐的目标,解决了管道阻塞问题,达到了连续生产目的,彻底改变了蒸饭机至发酵罐间物料自动输送的难题。

  4. Laser-induced cavitation based micropump

    NARCIS (Netherlands)

    Dijkink, Rory; Ohl, Claus-Dieter

    2008-01-01

    Lab-on-a-chip devices are in strong demand as versatile and robust pumping techniques. Here, we present a cavitation based technique, which is able to pump a volume of 4000 m3 within 75 s against an estimated pressure head of 3 bar. The single cavitation event is created by focusing a laser pulse in

  5. Clinical curative effect observation of continuous transfusion of heparin sodium combined with urokinase and warfarin by micropump in the treatment of deep venous thrombosis%微量泵持续输注肝素钠联合尿激酶、华法林治疗下肢深静脉血栓形成的临床效果观察

    Institute of Scientific and Technical Information of China (English)

    赵晓玲; 王明; 陈建明

    2016-01-01

    Objective:To investigate the clinical curative effect of continuous transfusion of heparin sodium combined with urokinase and warfarin by micropump in the treatment of deep venous thrombosis.Methods:86 cases of patients with deep venous thrombosis were divided into two groups randomly.The treatment group was treated with continuous transfusion of heparin sodium combined with urokinase and warfarin by micropump on the basis of conventional treatment,the control group was treated with urokinase,warfarin and low molecular heparin calcium on the basis of conventional treatment,the cure rate and effective rate of the two groups were compared.Results:The cure rate of the treatment group was 72.5%,and the total effective rate was 89.7%.The cure rate of the control group was 60.2%,and the total effective rate was 78.9%.The difference of clinical curative effect between the two groups was statistically significant(P<0.05).No serious bleeding events occurred in the two groups.Conclusion:The clinical curative effect of continuous transfusion of heparin sodium combined with urokinase and warfarin by micropump in the treatment of deep venous thrombosis was significantly better than that of low molecular heparin calcium combined with urokinase and warfarin,and the bleeding events were not significantly increased.%目的:探讨微量泵持续输注肝素钠联合尿激酶、华法林治疗下肢深静脉血栓形成的临床效果.方法:收治下肢深静脉血栓形成患者86例,随机分为两组.治疗组在常规治疗基础上,以微量泵持续输注肝素钠联合尿激酶、华法林,对照组在常规治疗基础上给予尿激酶、华法林、低分子肝素钙,比较两组治愈率及有效率.结果:治疗组治愈率 72.5%,总有效率 89.7%.对照组治愈率 60.2%,总有效率 78.9%.两组临床疗效比较,差异具有统计学意义(P<0.05).两组均未出现严重出血事件.结论:微量泵持续输注肝素钠联合尿激酶、华法林治疗下肢深静

  6. Clinical efficacy of micro-pump injection of nitroglycerin and sodium nitroprusside in the treatment of hypertensive crisis%静脉微泵注射硝酸甘油与硝普钠治疗高血压危象的效果观察

    Institute of Scientific and Technical Information of China (English)

    朱海龙; 王军; 王英; 梁夷; 张毅

    2012-01-01

    Objective To observe the clinical efficacy of micro-pump injection of nitroglycerin and sodium nitroprusside in the treatment of hypertensive crisis. Methods Sixty-eight patients were randomly divided into two groups, and recieved micro-pump injection of nitroglycerin (group A) or sodium nitroprusside (group B). The clinical efficacy were observed. Results The total effective rate of lowering blood pressure 94.12% in group A and 94.12% in group B, with no statistically significant difference between the two groups (P>0.05). But the duration of the lowering blood pressure was significantly shorter in group B than group A (P<0.05). The effective rate within 30 minutes was 67.65% in group B, but only 26.47% in group A. Conclusion For patients with hypertensive crisis, the clinical effect of sodium nitroglycerin and sodium nitroprusside is similar in lowering blood pressure, but sodium nitroprusside needs significantly shorter duration.%目的 观察静脉微泵注射硝酸甘油与硝普钠在高血压危象患者治疗中的降压效果.方法 68例高血压危象患者随机分成两组,分别行静脉微泵注射硝酸甘油与硝普钠行降压治疗,观察疗效.结果 硝酸甘油组与硝普钠组的降压总有效率相似(94.12%与94.12%,P>0.05),但降压达标时间硝普钠组短于硝酸甘油组(30 min显效率分别为67.65%与26.47%,P<0.05).结论 对于高血压危象患者,两种药物降压效果相似,均可选择.如果需要更快速地控制血压则首选硝普钠.

  7. 基于微生物代谢成分的电化学多参数检测平台微泵设计∗%Design of Micropump for Parallel Multi-Parameter Detection of Microbial Metabolic Components Based on Electrochemical Platform

    Institute of Scientific and Technical Information of China (English)

    徐莹; 胡正添; 郭淼

    2015-01-01

    There are some crucial problems in design of parallel multi-parameter detection platform. This paper puts forward a parallel detection platform by electrochemistry method to analyze the antibiotic residue components in micro-bial metabolites,which quantitatively showed the influence of antibiotics on physiological environment,membrane ad-herence and metabolites of microorganism in real time. According to the required accuracy of antibiotic detection lim-it,the fluid volume for single detection should be controlled within 20 μL/min~100 μL/min. Therefore,this paper comprehensively analyzed the static field,dynamic field and fluid field of the micro pump by the finite element method to make sure that the precision and controllability of pump design meet the measurement requirements,which was the key point in the detection platform. Results showed that the micro-pump flow rate was 52.864μL/min when the pump was driven by 20 Hz,±40 V AC voltage,and the relations between frequency and voltage to control the real-time change of flow rate were also discussed. Moreover,the passive valve micro pump was further analyzed on mechanical characteristics and the optimized pump fix end size(0.4 mm×0.5 mm). Finally,verified experiment of the obtained simulation data for flow rate compared with PSS20 commercial micro-pump was done with the error rate of 6. 7%, which proved the feasibility and accuracy of the finite element method,and provided a good reference for the design and improvement of micro-pump as well as the parallel multi-parameter detection platform.%本文提出一种基于抗生素作用下的微生物膜阻抗及代谢液微量残留物分析的电化学并行检测平台,从量化角度实时反映抗生素对微生物的膜贴附变化及代谢成分的影响。根据现有抗生素电化学检测单元的检测精度,待测生理溶液的进样体积需控制在20μL/min~100μL/min,因此本文针对平台中的关键部分———微泵单元采用有限元

  8. Design of Micropump for Parallel Multi-Parameter Detection of Microbial Metabolic Components Based on Electrochemical Platform%基于微生物代谢成分的电化学多参数检测平台微泵设计∗

    Institute of Scientific and Technical Information of China (English)

    徐莹; 胡正添; 郭淼

    2015-01-01

    There are some crucial problems in design of parallel multi-parameter detection platform. This paper puts forward a parallel detection platform by electrochemistry method to analyze the antibiotic residue components in micro-bial metabolites,which quantitatively showed the influence of antibiotics on physiological environment,membrane ad-herence and metabolites of microorganism in real time. According to the required accuracy of antibiotic detection lim-it,the fluid volume for single detection should be controlled within 20 μL/min~100 μL/min. Therefore,this paper comprehensively analyzed the static field,dynamic field and fluid field of the micro pump by the finite element method to make sure that the precision and controllability of pump design meet the measurement requirements,which was the key point in the detection platform. Results showed that the micro-pump flow rate was 52.864μL/min when the pump was driven by 20 Hz,±40 V AC voltage,and the relations between frequency and voltage to control the real-time change of flow rate were also discussed. Moreover,the passive valve micro pump was further analyzed on mechanical characteristics and the optimized pump fix end size(0.4 mm×0.5 mm). Finally,verified experiment of the obtained simulation data for flow rate compared with PSS20 commercial micro-pump was done with the error rate of 6. 7%, which proved the feasibility and accuracy of the finite element method,and provided a good reference for the design and improvement of micro-pump as well as the parallel multi-parameter detection platform.%本文提出一种基于抗生素作用下的微生物膜阻抗及代谢液微量残留物分析的电化学并行检测平台,从量化角度实时反映抗生素对微生物的膜贴附变化及代谢成分的影响。根据现有抗生素电化学检测单元的检测精度,待测生理溶液的进样体积需控制在20μL/min~100μL/min,因此本文针对平台中的关键部分———微泵单元采用有限元

  9. A thermopneumatic micropump based on micro-engineering techniques

    NARCIS (Netherlands)

    Pol, van de F.C.M.; Lintel, van H.T.G.; Elwenspoek, M.; Fluitman, J.H.J.

    1990-01-01

    The design, working principle and realization of an electro-thermopneumatic liquid pump based on micro-engineering techniques are described. The pump, which is of the reciprocating displacement type, comprises a pump chamber, a thin silicon pump membrane and two silicon check valves to direct the fl

  10. A thermopneumatic micropump based on micro-engineering techniques

    OpenAIRE

    Pol, van der, P.; Lintel, van, H.T.G.; Elwenspoek, M; Fluitman, J.H.J.

    1990-01-01

    The design, working principle and realization of an electro-thermopneumatic liquid pump based on micro-engineering techniques are described. The pump, which is of the reciprocating displacement type, comprises a pump chamber, a thin silicon pump membrane and two silicon check valves to direct the flow. The dynamic pressure of an amount of gas contained in a cavity, controlled by resistive heating, actuates the pump membrane. The cavity, chambers, channels and valves are realized in silicon wa...

  11. Deterministic transport of particles in a micro-pump

    CERN Document Server

    Beltrame, Philippe; Hänggi, Peter

    2012-01-01

    We study the drift of suspended micro-particles in a viscous liquid pumped back and forth through a periodic lattice of pores (drift ratchet). In order to explain the particle drift observed in such an experiment, we present an one-dimensional deterministic model of Stokes' drag. We show that the stability of oscillations of particle is related to their amplitude. Under appropriate conditions, particles may drift and two mechanisms of transport are pointed out. The first one is due to an spatio-temporal synchronization between the fluid and particle motions. As results the velocity is locked by the ratio of the space periodicity over the time periodicity. The direction of the transport may switch by tuning the parameters. Noteworthy, its emergence is related to a lattice of 2-periodic orbits but not necessary to chaotic dynamics. The second mechanism is due to an intermittent bifurcation and leads to a slow transport composed by long time oscillations following by a relative short transport to the next pore. ...

  12. Single-pulse dynamics and flow rates of inertial micropumps

    CERN Document Server

    Govyadinov, A N; Markel, D P; Torniainen, E D

    2015-01-01

    Bubble-driven inertial pumps are a novel method of moving liquids through microchannels. We combine high-speed imaging, computational fluid dynamics (CFD) simulations and an effective one-dimensional model to study the fundamentals of inertial pumping. Single-pulse flow through 22 x 17 um2 U-shaped channels containing 4-um polystyrene tracer beads has been imaged with a high-speed camera. The results are used to calibrate the CFD and one-dimensional models to extract an effective bubble strength. Then the frequency dependence of inertial pumping is studied both experimentally and numerically. The pump efficiency is found to gradually decrease once the successive pulses start to overlap in time.

  13. A microfluidic device based on an evaporation-driven micropump

    NARCIS (Netherlands)

    Nie, C.; Frijns, A.J.H.; Mandamparambil, R.; Toonder, J.M.J. den

    2015-01-01

    In this paper we introduce a microfluidic device ultimately to be applied as a wearable sweat sensor. We show proof-of-principle of the microfluidic functions of the device, namely fluid collection and continuous fluid flow pumping. A filter-paper based layer, that eventually will form the interface

  14. Fabrication of a peristaltic micro pump with novel cascaded actuators

    International Nuclear Information System (INIS)

    This paper presents the fabrication of an all-PDMS (polydimethylsiloxane) micro pump with novel cascaded actuators as dynamic valves. The micro pump consists of three pneumatic actuators in series and a micro fluidic channel connecting two fluidic inlet and outlet ports. The three-layer bonded pump structure is fabricated through a typical moulding process of PDMS and a simple heating process for the PDMS-to-PDMS bonding. The total size of the micro pump is 5 mm × 5 mm. The dynamic valve pattern of the single actuator is observed under various operational conditions of the square-wave input signal for the estimation of its volume stroke. The maximum volume stroke of the pneumatic actuator for liquid is about 85% of the volume of the liquid chamber. Three types of liquid-pumping tests are performed for characterization of the micro pump such as backpressure, frequency and viscous liquids. The flow rate of the de-ionized (DI) water is about 73.9 nl min−1 at zero backpressure. As the hydraulic difference between inlet and outlet ports increases, the flow rate gradually decreases. In the case of the frequency responses, the micro pump has the maximum flow rate of the DI water at 2 Hz. The viscosity-dependent flow rate of the working fluids is also observed

  15. Evaluation of peristaltic micromixers for highly integrated microfluidic systems.

    Science.gov (United States)

    Kim, Duckjong; Rho, Hoon Suk; Jambovane, Sachin; Shin, Soojeong; Hong, Jong Wook

    2016-03-01

    Microfluidic devices based on the multilayer soft lithography allow accurate manipulation of liquids, handling reagents at the sub-nanoliter level, and performing multiple reactions in parallel processors by adapting micromixers. Here, we have experimentally evaluated and compared several designs of micromixers and operating conditions to find design guidelines for the micromixers. We tested circular, triangular, and rectangular mixing loops and measured mixing performance according to the position and the width of the valves that drive nanoliters of fluids in the micrometer scale mixing loop. We found that the rectangular mixer is best for the applications of highly integrated microfluidic platforms in terms of the mixing performance and the space utilization. This study provides an improved understanding of the flow behaviors inside micromixers and design guidelines for micromixers that are critical to build higher order fluidic systems for the complicated parallel bio/chemical processes on a chip. PMID:27036809

  16. Evaluation of peristaltic micromixers for highly integrated microfluidic systems

    Science.gov (United States)

    Kim, Duckjong; Rho, Hoon Suk; Jambovane, Sachin; Shin, Soojeong; Hong, Jong Wook

    2016-03-01

    Microfluidic devices based on the multilayer soft lithography allow accurate manipulation of liquids, handling reagents at the sub-nanoliter level, and performing multiple reactions in parallel processors by adapting micromixers. Here, we have experimentally evaluated and compared several designs of micromixers and operating conditions to find design guidelines for the micromixers. We tested circular, triangular, and rectangular mixing loops and measured mixing performance according to the position and the width of the valves that drive nanoliters of fluids in the micrometer scale mixing loop. We found that the rectangular mixer is best for the applications of highly integrated microfluidic platforms in terms of the mixing performance and the space utilization. This study provides an improved understanding of the flow behaviors inside micromixers and design guidelines for micromixers that are critical to build higher order fluidic systems for the complicated parallel bio/chemical processes on a chip.

  17. A peristaltic pump driven 89Zr separation module

    DEFF Research Database (Denmark)

    Siikanen, J.; Peterson, M.; Tran, T.;

    2012-01-01

    To facilitate the separation of 89Zr produced in yttrium foils, an automated separation module was designed and assembled. The module separates more than 85% of produced 89Zr - activity in 3 g foils in less than 90 min. About 10 % remains in the dissolving vial. The quality of the separated 89Zr...

  18. A peristaltic pump driven 89Zr separation module

    DEFF Research Database (Denmark)

    Siikanen, J.; Peterson, M.; Tran, T.;

    2012-01-01

    To facilitate the separation of 89Zr produced in yttrium foils, an automated separation module was designed and assembled. The module separates more than 85% of produced 89Zr - activity in 3 g foils in less than 90 min. About 10 % remains in the dissolving vial. The quality of the separated 89Zr ...... activity was investigated for labeling of the HER2-binding monoclonal antibody fragment, trastuzumab-Fab....

  19. A New Concept of a Drug Delivery System with Improved Precision and Patient Safety Features

    Directory of Open Access Journals (Sweden)

    Florian Thoma

    2014-12-01

    Full Text Available This paper presents a novel dosing concept for drug delivery based on a peristaltic piezo-electrically actuated micro membrane pump. The design of the silicon micropump itself is straight-forward, using two piezoelectrically actuated membrane valves as inlet and outlet, and a pump chamber with a piezoelectrically actuated pump membrane in-between. To achieve a precise dosing, this micropump is used to fill a metering unit placed at its outlet. In the final design this metering unit will be made from a piezoelectrically actuated inlet valve, a storage chamber with an elastic cover membrane and a piezoelectrically actuated outlet valve, which are connected in series. During a dosing cycle the metering unit is used to adjust the drug volume to be dispensed before delivery and to control the actually dispensed volume. To simulate the new drug delivery concept, a lumped parameter model has been developed to find the decisive design parameters. With the knowledge taken from the model a drug delivery system is designed that includes a silicon micro pump and, in a first step, a silicon chip with the storage chamber and two commercial microvalves as a metering unit. The lumped parameter model is capable to simulate the maximum flow, the frequency response created by the micropump, and also the delivered volume of the drug delivery system.

  20. Characterization of flowreversal in anodically bonded glass-based AC electrokinetic micropumps

    DEFF Research Database (Denmark)

    Gregersen, Misha Marie; Olesen, Laurits Højgaard; Brask, Anders;

    2007-01-01

    Microfluidic chips have been fabricated to study electrokinetic pumping generated by a low voltage AC signal applied to an asymmetric electrode array. A measurement procedure has been established and followed carefully resulting in a high degree of reproducibility of the measurements. Depending...

  1. Finite element computation of electromechanical micro-switches and micro-pump actuators

    OpenAIRE

    Lejeune, Jean-Michel; Rochus, Véronique; Golinval, Jean-Claude

    2004-01-01

    a new methodology to model the electromechanical behavior of microscale system components is presented. The original approach proposed in this paper is based on a unified FE formulation of the strong electromechanical interaction problem, in which both the electric and the mechanical fields are considered simultaneously. To this aim, finite elements based on the Mindlin shell theory are implemented. In order to illustrate the proposed methodology, numerical results are presented on the mod...

  2. Micropump Fuel Mix Control for Novel Miniature Direct Methanol Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Energies and Power Densities of Direct Methanol Fuel Cells (DMFCs) are limited by the size and weight associated with the liquid pump, which must circulate the...

  3. Highly Capable Micropump-fed Propulsion System for Proximity Operations, Landing and Ascent Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Flight Works is proposing to expand its work in micro-gear-pumps for propulsion applications in order to provide a highly capable propulsion and attitude control...

  4. Development of highly integrated magetically and electrostatically actuated micropumps : LDRD 64709 final report.

    Energy Technology Data Exchange (ETDEWEB)

    Sosnowchik, Brian D. (Pennsylvania State University, University Park, PA); Galambos, Paul C.; Hendrix, Jason R. (Florida State University, Tallahassee, FL); Zwolinski, Andrew (Florida State University, Tallahassee, FL)

    2003-12-01

    The pump and actuator systems designed and built in the SUMMiT{trademark} process, Sandia's surface micromachining polysilicon MEMS (Micro-Electro-Mechanical Systems) fabrication technology, on the previous campus executive program LDRD (SAND2002-0704P) with FSU/FAMU (Florida State University/Florida Agricultural and Mechanical University) were characterized in this LDRD. These results demonstrated that the device would pump liquid against the flow resistance of a microfabricated channel, but the devices were determined to be underpowered for reliable pumping. As a result a new set of SUMMiT{trademark} pumps with actuators that generate greater torque will be designed and submitted for fabrication. In this document we will report details of dry actuator/pump assembly testing, wet actuator/pump testing, channel resistance characterization, and new pump/actuator design recommendations.

  5. Topology and shape optimization of induced-charge electro-osmotic micropumps

    DEFF Research Database (Denmark)

    Gregersen, Misha Marie; Okkels, Fridolin; Bazant, M. Z.;

    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...

  6. A NEW TYPE OF MICROPUMP DRIVEN BY A LOW ELECTRIC VOLTAGE

    Institute of Scientific and Technical Information of China (English)

    Guo Shuxiang; ASAKA Kinji

    2004-01-01

    In this paper, we propose a new prototype model of a micro pump using ICPF (Ionic Conducting Polymer Film) actuator as the servo actuator. This micro pump consists of two active oneway valves that make use of the same ICPF actuator. The overall size of this micro pump prototype is 12mm in diameter and 20 mm in length. The actuating mechanism is as follows: (1) The ICPF actuator as the diaphragm is bent into anode side by application of electricity. Then the volume of the pump chamber increases, resulting in the inflow of liquid from the inlet to the chamber. (2) By changing the current direction, the volume of the pump chamber decreases, resulting in the liquid flow from the chamber to the outlet. (3) The ICPF actuator is put on a sine voltage, the micro pump provides liquid flow from the inlet to the outlet continuously. Characteristic of the micro pump is measured. The experimental results indicate that the micro pump has the satisfactory responses.

  7. Remotely powered self-propelling particles and micropumps based on miniature diodes

    Science.gov (United States)

    Chang, Suk Tai; Paunov, Vesselin N.; Petsev, Dimiter N.; Velev, Orlin D.

    2007-03-01

    Microsensors and micromachines that are capable of self-propulsion through fluids could revolutionize many aspects of technology. Few principles to propel such devices and supply them with energy are known. Here, we show that various types of miniature semiconductor diodes floating in water act as self-propelling particles when powered by an external alternating electric field. The millimetre-sized diodes rectify the voltage induced between their electrodes. The resulting particle-localized electro-osmotic flow propels them in the direction of either the cathode or the anode, depending on their surface charge. These rudimentary self-propelling devices can emit light or respond to light and could be controlled by internal logic. Diodes embedded in the walls of microfluidic channels provide locally distributed pumping or mixing functions powered by a global external field. The combined application of a.c. and d.c. fields in such devices allows decoupling of the velocity of the particles and the liquid and could be used for on-chip separations.

  8. Highly Efficient and Robust Micropump for Small Spacecraft Thermal Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — With the introduction of low-cost, small, rapidly configurable spacecraft, the need for robust, versatile, readily deployable, and easily ground-testable thermal...

  9. MHD peristaltic motion of Johnson-Segalman fluid in a channel with compliant walls

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, T. [Department of Mathematics, Quaid-i-Azam University, Islamabad 44000 (Pakistan)], E-mail: t_pensy@hotmail.com; Javed, Maryiam [Department of Mathematics, Quaid-i-Azam University, Islamabad 44000 (Pakistan); Asghar, S. [Department of Mathematical Sciences, COMSATS Institute of Information Technology, H-8, Islamabad (Pakistan)

    2008-07-21

    A mathematical model for magnetohydrodynamic (MHD) flow of a Johnson-Segalman fluid in a channel with compliant walls is analyzed. The flow is engendered due to sinusoidal waves on the channel walls. A series solution is developed for the case in which the amplitude ratio is small. Our computations show that the mean axial velocity of a Johnson-Segalman fluid is smaller than that of a viscous fluid. The variations of various interesting dimensionless parameters are graphed and discussed.

  10. Peristaltic motion of a Johnson-Segalman fluid in a planar channel

    Directory of Open Access Journals (Sweden)

    Hayat T.

    2003-01-01

    Full Text Available This paper is devoted to the study of the two-dimensional flow of a Johnson-Segalman fluid in a planar channel having walls that are transversely displaced by an infinite, harmonic travelling wave of large wavelength. Both analytical and numerical solutions are presented. The analysis for the analytical solution is carried out for small Weissenberg numbers. (A Weissenberg number is the ratio of the relaxation time of the fluid to a characteristic time associated with the flow. Analytical solutions have been obtained for the stream function from which the relations of the velocity and the longitudinal pressure gradient have been derived. The expression of the pressure rise over a wavelength has also been determined. Numerical computations are performed and compared to the perturbation analysis. Several limiting situations with their implications can be examined from the presented analysis.

  11. Peristaltic Motion of Power-Law Fluid with Heat and Mass Transfer

    Institute of Scientific and Technical Information of China (English)

    T.Hayat; S.Hina; Awatif A.Hendi

    2011-01-01

    @@ The effects of wall properties and heat and mass transfer on the peristalsis in a power-law fluid are investigated.The solutions for the stream function, temperature, concentration and heat transfer coefficient are obtained.The axial velocity, temperature and mass concentration are studied for different emerging parameters.

  12. Mechanisms of Barrett's oesophagus (clinical): LOS dysfunction, hiatal hernia, peristaltic defects.

    Science.gov (United States)

    Roman, Sabine; Kahrilas, Peter J

    2015-02-01

    Barrett's oesophagus, with the potential to develop into oesophageal adenocarcinoma (OAC), is a major complication of gastrooesophageal reflux disease (GORD). However, about 50% of patients developing OAC had no known GORD beforehand. Hence, while GORD symptoms, oesophagitis, and Barrett's have a number of common determinants (oesophagogastric junction (OGJ) incompetence, impaired oesophageal clearance mechanisms, hiatus hernia) they also have some independent determinants. Further, although excess oesophageal acid exposure plays a major role in the genesis of long-segment Barrett's oesophagus there is minimal evidence supporting this for short-segment Barrett's. Hence, these may have unique pathophysiological features as well. Long-segment Barrett's seems to share most, if not all, of the risk factors for oesophagitis, particularly high-grade oesophagitis. However, it is uncertain if OGJ function and acid clearance are more severely impaired in patients with long-segment Barrett's compared to patients with high-grade oesophagitis. With respect to short-segment Barrett's, the acid pocket may play an important pathogenic role. Conceptually, extension of the acid pocket into the distal oesophagus, also known as intra-sphincteric reflux, provides a mechanism or acid exposure of the distal osophageal mucosa without the occurrence of discrete reflux events, which are more likely to prompt reflux symptoms and lead to the development of oesophagitis. Hence, intra-sphincteric reflux related to extension of the acid/no acid interface at the proximal margin of the acid pocket may be key in the development of short segment Barrett's. However, currently this is still somewhat speculative and further studies are required to confirm this. PMID:25743453

  13. Mechano-optical switching in a mems integrated photonic crystal slab waveguide

    NARCIS (Netherlands)

    Abdulla, S.M.C.; Kauppinen, L.J.; Dijkstra, M.A.; Berenschot, J.W.; Boer, de M.J.; Ridder, de R.M.; Krijnen, G.J.M.

    2011-01-01

    A photonic crystal slab waveguide (PhC-WG) with an integrated MEMS bimorph cantilever actuator has been successfully fabricated using deep UV lithography and surface micromaching techniques. The cantilever is equipped with tips that are self-aligned with respect to the holes of the PhC-WG such that

  14. Electrohydrodynamic pumping in microsystems

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Antonio, E-mail: ramos@us.es [Deptartamento de Electronica y Electromagnetismo, Universidad de Sevilla, Avenida Reina Mercedes s/n, 41012-Sevilla (Spain)

    2011-06-23

    The physical principles behind the electrohydrodynamic (EHD) actuation in microsystems is presented by reviewing five different EHD micropumps. These are classified into two groups: micropumps that exert electric forces in the liquid bulk and micropumps that exert forces in the diffuse double layer. This review of five EHD micropumps allows us to analyse the EHD actuation ranging from very insulating liquids to electrolytic solutions.

  15. A surface acoustic wave-driven micropump for particle uptake investigation under physiological flow conditions in very small volumes

    Directory of Open Access Journals (Sweden)

    Florian G. Strobl

    2015-02-01

    Full Text Available Static conditions represent an important shortcoming of many in vitro experiments on the cellular uptake of nanoparticles. Here, we present a versatile microfluidic device based on acoustic streaming induced by surface acoustic waves (SAWs. The device offers a convenient method for introducing fluid motion in standard cell culture chambers and for mimicking capillary blood flow. We show that shear rates over the whole physiological range in sample volumes as small as 200 μL can be achieved. A precise characterization method for the induced flow profile is presented and the influence of flow on the uptake of Pt-decorated CeO2 particles by endothelial cells (HMEC-1 is demonstrated. Under physiological flow conditions the particle uptake rates for this system are significantly lower than at low shear conditions. This underlines the vital importance of the fluidic environment for cellular uptake mechanisms.

  16. An all-polymer micropump based on the conductive polymer poly(3,4-ethylenedioxythiophene) and a polyurethane channel system

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; West, Keld; Hassager, Ole;

    2007-01-01

    An all-polymer micropunlp was realized using the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDT) as the active cODlponent. The pUlnping effect originated fronl an ac potential applied to an aSylnlnetric array of interdigitat.ed electrodes. The PEDT electrodes were fabricated using opti...... of t.he conducting polylner electrodes by an insulating polYlTIer layer prevented electrode break-down at the cost of puolping efficiency. Continuous punlping for 40 nlin at 20 fJ..,m s-l without detectable pump degradation was delTIOnstrated in this configuration....

  17. Design and Analysis of a High Force, Low Voltage and High Flow Rate Electro-Thermal Micropump

    OpenAIRE

    Ghader Yosefi; Sattar Mirzakuchaki; Farshid Raissi; Saeid Afrang

    2014-01-01

    This paper presents the design and simulation of an improved electro-thermal micromachined pump for drug delivery applications. Thermal actuators, which are a type of Micro Electro Mechanical system (MEMS) device, are highly useful because of their ability to deliver with great force and displacement. Thus, our structure is based on a thermal actuator that exploits the Joule heating effect and has been improved using the springy length properties of MEMS chevron beams. The Joule heating effec...

  18. A feasibility study on using inkjet technology, micropumps, and MEMs as fuel injectors for bipropellant rocket engines

    OpenAIRE

    Glynne-Jones, Peter; Coletti, Michele; White, Neil M; Gabriel, Stephen; Bramanti, Cristina

    2008-01-01

    Control over drop size distributions, injection rates, and geometrical distribution of fuel and oxidizer sprays in bi-propellant rocket engines has the potential to produce more efficient, more stable, less polluting rocket engines. This control also offers the potential of an engine that can be throttled, working efficiently over a wide range of output thrusts. Inkjet printing technologies, MEMS fuel atomizers, and piezoelectric injectors similar in concept to those used in diesel engines ar...

  19. 微泵的结构与流体分析%Analysis on the structure and hydrokinetics of micropump

    Institute of Scientific and Technical Information of China (English)

    贾建援; 黄新波; 康春霞

    2004-01-01

    利用扩散阀/喷嘴的流体特性设计了一种无活动阀压电式微泵;应用小挠度弹性弯曲理论,导出圆形压电复合层薄板的弹性曲面微分方程和复合层薄板的中性面位置方程;应用压电理论导出压电薄膜的边缘电场分布;应用微流体力学理论导出微泵单次循环的净流量.结合华盛顿大学的压电式微泵模型理论算出其最大流量为958μl/min,与其试验结果相吻合.

  20. Isolation of Individual Egg Cells and Zygotes in Alstroemeria Followed by Manual Selection with a Microcapillary-connected Micropump

    OpenAIRE

    Hoshino, Yoichiro; MURATA, Naho; Shinoda, Koichi

    2006-01-01

    Aims: To develop a procedure for isolating living egg cells and zygotes from Alstroemeria ovules. Scope: We attempted to isolate egg cells and zygotes from the ovules of Alstroemeria aurea. The ovules were histologically observed using a clearing procedure which revealed the localization and sizes of the embryo sacs and egg apparatus within the ovules. For the isolation of egg cells, ovules were cut into sections with a surgical blade and treated with an enzyme solution. Subsequently, these o...

  1. Design and Analysis of a High Force, Low Voltage and High Flow Rate Electro-Thermal Micropump

    Directory of Open Access Journals (Sweden)

    Ghader Yosefi

    2014-12-01

    Full Text Available This paper presents the design and simulation of an improved electro-thermal micromachined pump for drug delivery applications. Thermal actuators, which are a type of Micro Electro Mechanical system (MEMS device, are highly useful because of their ability to deliver with great force and displacement. Thus, our structure is based on a thermal actuator that exploits the Joule heating effect and has been improved using the springy length properties of MEMS chevron beams. The Joule heating effect results in a difference in temperature and therefore displacement in the beams (actuators. Simulation results show that a maximum force of 4.4 mN and a maximum flow rate of 16 μL/min can be obtained by applying an AC voltage as low as 8 V at different frequencies ranging from 1 to 32 Hz. The maximum temperature was a problem at the chevron beams and the center shaft. Thus, to locally increase the temperature of the chevron beams alone and not that of the pumping diaphragm: (1 The air gaps 2 μm underneath and above the device layer were optimized for heat transfer. (2 Release holes and providing fins were created at the center shaft and actuator, respectively, to decrease the temperature by approximately 10 °C. (3 We inserted and used a polymer tube to serve as an insulator and eliminate leakage problems in the fluidic channel.

  2. Numerical analysis for peristaltic transport of Carreau-Yasuda fluid with variable thermal conductivity and convective conditions

    Institute of Scientific and Technical Information of China (English)

    F M Abbasi; T Hayat; B Ahmad

    2015-01-01

    Peristalsis of Carreau-Yasuda fluid is investigated. Analysis is carried out in the presence of velocity slip and convective boundary conditions. Thermal conductivity of the fluid is taken to be temperature dependent. Lubrication analysis is used in the formulation of the problem. Resulting nonlinear system of equations is solved numerically. Impact of embedded parameters on the quantities of interest is examined through graphs and tables. Comparison of the behavior of the Carreau-Yasuda, Carreau and Newtonian fluid models is presented. Results show that the heat transfer rate at the wall for the Carreau fluid model is large when compared with the Newtonian or the Carreau-Yasuda fluid model. Also the heat transfer rate at the wall decreases with increase in the velocity slip and variable thermal conductivity parameters. Further, an increase in the Biot number reduces the fluid temperature by a considerable amount.

  3. Spontaneous peristaltic airway contractions propel lung liquid through the bronchial tree of intact and fetal lung explants.

    Science.gov (United States)

    Schittny, J C; Miserocchi, G; Sparrow, M P

    2000-07-01

    Spontaneous contractions of the fetal airways are a well recognized but poorly characterized phenomenon. In the present study spontaneous narrowing of the airways was analyzed in freshly isolated lungs from early to late gestation in fetal pigs and rabbits and in cultured fetal mouse lungs. Propagating waves of contraction traveling proximal to distal were observed in fresh lungs throughout gestation which displaced the lung liquid along the lumen. In the pseudoglandular and canalicular stages (fetal pigs) the frequency ranged from 2.3 to 3.3 contractions/min with a 39 to 46% maximum reduction of lumen diameter. In the saccular stage (rabbit) the frequency was 10 to 12/min with a narrowing of approximately 30%. In the organ cultures the waves of narrowing started at the trachea in whole lungs, or at the main bronchus in lobes (5.2 +/- 1.5 contractions/min, 22 +/- 8% reduction of lumen diameter), and as they proceeded distally along the epithelial tubes the luminal liquid was shifted toward the terminal tubules, which expanded the endbuds. As the tubules relaxed the flow of liquid was reversed. Thus the behavior of airway smooth muscle in the fetal lung is phasic in type (like gastrointestinal muscle) in contrast to that in postnatal lung, where it is tonic. An intraluminal positive pressure of 2.33 +/- 0.77 cm H(2)O was recorded in rabbit fetal trachea. It is proposed that the active tone of the smooth muscle maintains the positive intraluminal pressure and acts as a stimulus to lung growth via the force exerted across the airway wall and adjacent parenchyma. The expansion of the compliant endbuds by the fluid shifts at the airway tip may promote their growth into the surrounding mesenchyme.

  4. Buttressing staples with cholecyst-derived extracellular matrix (CEM) reinforces staple lines in an ex vivo peristaltic inflation model.

    LENUS (Irish Health Repository)

    Burugapalli, Krishna

    2008-11-01

    Staple line leakage and bleeding are the most common problems associated with the use of surgical staplers for gastrointestinal resection and anastomotic procedures. These complications can be reduced by reinforcing the staple lines with buttressing materials. The current study reports the potential use of cholecyst-derived extracellular matrix (CEM) in non-crosslinked (NCEM) and crosslinked (XCEM) forms, and compares their mechanical performance with clinically available buttress materials [small intestinal submucosa (SIS) and bovine pericardium (BP)] in an ex vivo small intestine model.

  5. Design and experimental gait analysis of a multi-segment in-pipe robot inspired by earthworm's peristaltic locomotion

    Science.gov (United States)

    Fang, Hongbin; Wang, Chenghao; Li, Suyi; Xu, Jian; Wang, K. W.

    2014-03-01

    This paper reports the experimental progress towards developing a multi-segment in-pipe robot inspired by earthworm's body structure and locomotion mechanism. To mimic the alternating contraction and elongation of a single earthworm's segment, a robust, servomotor based actuation mechanism is developed. In each robot segment, servomotor-driven cords and spring steel belts are utilized to imitate the earthworm's longitudinal and circular muscles, respectively. It is shown that the designed segment can contract and relax just like an earthworm's body segment. The axial and radial deformation of a single segment is measured experimentally, which agrees with the theoretical predictions. Then a multisegment earthworm-like robot is fabricated by assembling eight identical segments in series. The locomotion performance of this robot prototype is then extensively tested in order to investigate the correlation between gait design and dynamic locomotion characteristics. Based on the principle of retrograde peristalsis wave, a gait generator is developed for the multi-segment earthworm-like robot, following which gaits of the robot can be constructed. Employing the generated gaits, the 8-segment earthworm-like robot can successfully perform both horizontal locomotion and vertical climb in pipes. By changing gait parameters, i.e., with different gaits, locomotion characteristics including average speed and anchor slippage can be significantly tailored. The proposed actuation method and prototype of the multi-segment in-pipe robot as well as the gait generator provide a bionic realization of earthworm's locomotion with promising potentials in various applications such as pipeline inspection and cleaning.

  6. Micro pumping methods based on AC electrokinetics and Electrorheologically actuated PDMS valves

    Science.gov (United States)

    Soni, Gaurav; Squires, Todd; Meinhart, Carl

    2006-11-01

    We have developed 2 different micropumping methods for transporting ionic fluids through microchannels. The first method is based on Induced Charge Electroosmosis (ICEO) and AC flow field-effect. We used an AC electric field to produce a symmetric ICEO flow on a planar electrode, called `gate'. In order to break the symmetry of ICEO, we applied an additional AC voltage to the gate electrode. Such modulation of the gate potential is called field effect and produces a unidirectional pumping over the gate surface. We used micro PIV to measure pumping velocities for a range of ionic concentration, AC frequency and gate voltage. We have also conducted numerical simulations to understand the deteriorating effect of lateral conduction of surface charge on the pumping velocities. The second method is based on vibration of a flexible PDMS diaphragm actuated by an electrorheological (ER) fluid. ER fluid is a colloidal suspension exhibiting a reversible liquid-to-solid transition under an electric field. This liquid-to-solid transition can yield very high shear stress and can be used to open and close a PDMS valve. Three such valves were fabricated and actuated in a peristaltic fashion in order to achieve positive displacement pumping of fluids.

  7. Towards a Multifunctional Electrochemical Sensing and Niosome Generation Lab-on-Chip Platform Based on a Plug-and-Play Concept

    Directory of Open Access Journals (Sweden)

    Adnane Kara

    2016-05-01

    Full Text Available In this paper, we present a new modular lab on a chip design for multimodal neurotransmitter (NT sensing and niosome generation based on a plug-and-play concept. This architecture is a first step toward an automated platform for an automated modulation of neurotransmitter concentration to understand and/or treat neurodegenerative diseases. A modular approach has been adopted in order to handle measurement or drug delivery or both measurement and drug delivery simultaneously. The system is composed of three fully independent modules: three-channel peristaltic micropumping system, a three-channel potentiostat and a multi-unit microfluidic system composed of pseudo-Y and cross-shape channels containing a miniature electrode array. The system was wirelessly controlled by a computer interface. The system is compact, with all the microfluidic and sensing components packaged in a 5 cm × 4 cm × 4 cm box. Applied to serotonin, a linear calibration curve down to 0.125 mM, with a limit of detection of 31 μ M was collected at unfunctionalized electrodes. Added sensitivity and selectivity was achieved by incorporating functionalized electrodes for dopamine sensing. Electrode functionalization was achieved with gold nanoparticles and using DNA and o-phenylene diamine polymer. The as-configured platform is demonstrated as a central component toward an “intelligent” drug delivery system based on a feedback loop to monitor drug delivery.

  8. Towards a Multifunctional Electrochemical Sensing and Niosome Generation Lab-on-Chip Platform Based on a Plug-and-Play Concept.

    Science.gov (United States)

    Kara, Adnane; Rouillard, Camille; Mathault, Jessy; Boisvert, Martin; Tessier, Frédéric; Landari, Hamza; Melki, Imene; Laprise-Pelletier, Myriam; Boisselier, Elodie; Fortin, Marc-André; Boilard, Eric; Greener, Jesse; Miled, Amine

    2016-01-01

    In this paper, we present a new modular lab on a chip design for multimodal neurotransmitter (NT) sensing and niosome generation based on a plug-and-play concept. This architecture is a first step toward an automated platform for an automated modulation of neurotransmitter concentration to understand and/or treat neurodegenerative diseases. A modular approach has been adopted in order to handle measurement or drug delivery or both measurement and drug delivery simultaneously. The system is composed of three fully independent modules: three-channel peristaltic micropumping system, a three-channel potentiostat and a multi-unit microfluidic system composed of pseudo-Y and cross-shape channels containing a miniature electrode array. The system was wirelessly controlled by a computer interface. The system is compact, with all the microfluidic and sensing components packaged in a 5 cm × 4 cm × 4 cm box. Applied to serotonin, a linear calibration curve down to 0.125 mM, with a limit of detection of 31 μ M was collected at unfunctionalized electrodes. Added sensitivity and selectivity was achieved by incorporating functionalized electrodes for dopamine sensing. Electrode functionalization was achieved with gold nanoparticles and using DNA and o-phenylene diamine polymer. The as-configured platform is demonstrated as a central component toward an "intelligent" drug delivery system based on a feedback loop to monitor drug delivery. PMID:27240377

  9. Towards a Multifunctional Electrochemical Sensing and Niosome Generation Lab-on-Chip Platform Based on a Plug-and-Play Concept

    Science.gov (United States)

    Kara, Adnane; Rouillard, Camille; Mathault, Jessy; Boisvert, Martin; Tessier, Frédéric; Landari, Hamza; Melki, Imene; Laprise-Pelletier, Myriam; Boisselier, Elodie; Fortin, Marc-André; Boilard, Eric; Greener, Jesse; Miled, Amine

    2016-01-01

    In this paper, we present a new modular lab on a chip design for multimodal neurotransmitter (NT) sensing and niosome generation based on a plug-and-play concept. This architecture is a first step toward an automated platform for an automated modulation of neurotransmitter concentration to understand and/or treat neurodegenerative diseases. A modular approach has been adopted in order to handle measurement or drug delivery or both measurement and drug delivery simultaneously. The system is composed of three fully independent modules: three-channel peristaltic micropumping system, a three-channel potentiostat and a multi-unit microfluidic system composed of pseudo-Y and cross-shape channels containing a miniature electrode array. The system was wirelessly controlled by a computer interface. The system is compact, with all the microfluidic and sensing components packaged in a 5 cm × 4 cm × 4 cm box. Applied to serotonin, a linear calibration curve down to 0.125 mM, with a limit of detection of 31 μM was collected at unfunctionalized electrodes. Added sensitivity and selectivity was achieved by incorporating functionalized electrodes for dopamine sensing. Electrode functionalization was achieved with gold nanoparticles and using DNA and o-phenylene diamine polymer. The as-configured platform is demonstrated as a central component toward an “intelligent” drug delivery system based on a feedback loop to monitor drug delivery. PMID:27240377

  10. Modeling and optimal design of multilayer thermal cantilever microactuators

    Institute of Scientific and Technical Information of China (English)

    FU JianYu; CHEN DaPeng; YE TianChun; JIAO BinBin; OU Yi

    2009-01-01

    A model of curvature and tip deflection of multilayer thermal cantilever actuators is derived. The sim-plified expression received from the model avoids inverting complex matrices enhances understanding and makes it easier to optimize the structure parameters. Experiment is performed, the modeled andexperimental results demonstrate the validity of the model, and it also indicates that ~oung's module makes great contribution to the deflection; therefore, thin layers cannot be ignored arbitrarily.

  11. Modeling and optimal design of multilayer thermal cantilever microactuators

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A model of curvature and tip deflection of multilayer thermal cantilever actuators is derived.The sim-plified expression received from the model avoids inverting complex matrices enhances understanding and makes it easier to optimize the structure parameters.Experiment is performed,the modeled and experimental results demonstrate the validity of the model,and it also indicates that Young’s module makes great contribution to the deflection;therefore,thin layers cannot be ignored arbitrarily.

  12. 聚合物PMMA材料的无阀微泵研制%Valve-less Micropump Development of the Polymer PMMA Material

    Institute of Scientific and Technical Information of China (English)

    蒋希赟

    2015-01-01

    The valve-less micro pump is often used to directly control micro pump flow, and it avoids the micro pump failure caused by the instability of the valve. This paper described the method of making a microfluidic devices micro pump with polymer PMMA material, put forward some methods of microfluidic manufacturing process and chose the suitable PMMA micro pump manufacturing method, then conducted the valve-less micro pump production and testing, and made flow rate and back pressure test of the micro pump produced with PMMA material, finally combined the developed valve-less micro pump and the integrated free-flow electrophoresis chip to test the its function effect.%无阀微泵经常被使用是为了直接控制微泵的流量,它避免了阀片的不稳定性引起的微泵失效。文章叙述了以聚合物PMMA为材料来制作微流体器件微泵,给出微流体制作工艺的几种方法并从中选出适合于PMMA微泵制作方法,然后进行无阀微泵制作与测试,并对用PMMA材料制作的微泵进行了流量和背压的测试,最后把所研制的无阀微泵与集成化自由流电泳芯片结合测试其功能效果。

  13. Optimal Design and Operation for a No-Moving-Parts-Valve (NMPV) Micro-Pump with a Diffuser Width of 500 μm

    OpenAIRE

    Jia-Ming Sun; Tzong-Shyng Leu; Chin-Tsan Wang

    2009-01-01

    A no-moving-parts-valve (NMPV) with a diffuser width of D = 500 microns was investigated in this study by numerical simulations at Reynolds numbers, ReD, ranging from 20 to 75, and expansion valve angles ranging from 30° < θ1 < 57° and 110° < θ2 < 120°. The D p,i value, 1.02 < D p,i < 1.14, is larger within the proposed range of the expansion valve angles. A flow channel structure with a depth of 500 micron is manufactured using yellow light lithography in this study. From p...

  14. Valve-less Micropump Development of the Polymer PMMA Material%聚合物PMMA材料的无阀微泵研制

    Institute of Scientific and Technical Information of China (English)

    蒋希赟

    2015-01-01

    The valve-less micro pump is often used to directly control micro pump flow, and it avoids the micro pump failure caused by the instability of the valve. This paper described the method of making a microfluidic devices micro pump with polymer PMMA material, put forward some methods of microfluidic manufacturing process and chose the suitable PMMA micro pump manufacturing method, then conducted the valve-less micro pump production and testing, and made flow rate and back pressure test of the micro pump produced with PMMA material, finally combined the developed valve-less micro pump and the integrated free-flow electrophoresis chip to test the its function effect.%无阀微泵经常被使用是为了直接控制微泵的流量,它避免了阀片的不稳定性引起的微泵失效。文章叙述了以聚合物PMMA为材料来制作微流体器件微泵,给出微流体制作工艺的几种方法并从中选出适合于PMMA微泵制作方法,然后进行无阀微泵制作与测试,并对用PMMA材料制作的微泵进行了流量和背压的测试,最后把所研制的无阀微泵与集成化自由流电泳芯片结合测试其功能效果。

  15. Numerical Simulation of a Colloidal Micropump by Dissipative Particle Dynamics%胶体微泵的耗散粒子动力学模拟

    Institute of Scientific and Technical Information of China (English)

    张光明; 陈硕

    2014-01-01

    应用耗散粒子动力学方法研究了胶体微泵.每个胶体小球按照既定的运动规律相继运动,从而可驱动流体.首先利用耗散粒子动力学方法计算了泊肃叶流动,验证了模拟的正确性.然后模拟了由六个胶体小球组成的周期性胶体微泵的工作过程.胶体颗粒与周围流体粒子之间采用了弹性碰撞模型;模拟中选择了合适的参数,从而可提高流体的粘度并保证DPD流体的不可压缩性.模拟结果与他人的实验数据进行了对比,两者很好吻合.模拟结果显示,胶体微泵的无量纲流量的绝对值随着小球运动ω的变小而增大;而随着ω的减小,无量纲流量的振幅也相应变大.

  16. Improvements in the technique of vascular perfusion-fixation employing a fluorocarbon-containing perfusate and a peristaltic pump controlled by pressure feedback

    DEFF Research Database (Denmark)

    Rostgaard, J; Qvortrup, K; Poulsen, Steen Seier

    1993-01-01

    oxygenated fluorocarbon to glutaraldehyde perfusate-fixatives, enough oxygen is made accessible for cellular respiration as well as for the oxygen-consuming chemical reactions of glutaraldehyde with the tissue. Data on anaesthesia, operative manoeuvres, mechanical components of the system, preparation...

  17. Electronic micropipettor: A versatile fluid propulsion and injection device for micro-flow analysis

    International Nuclear Information System (INIS)

    The shortage of ready to use small sized liquid propulsion and switching devices for microfluidic cells (μ-cell) is a bottleneck in the dissemination of micro-flow analysis (μ-FA), now that microfluidic electrochemical cells can be designed and assembled in any laboratory by thermal transfer of laser printed masks and CD-Rs. Microprocessor-controlled electronic pipettors, commercially available with minimum capacity of 10 μL, represent a compromise solution between oversized peristaltic pumps and tiny 'on a chip' micropumps and valves. The versatility of the electronic pipette coupled with the μ-cell (13-μm deep longitudinal channel) was demonstrated in three operation modes: SIA like, FIA like and direct injection analysis (DIA). Injections of 100 nL K4Fe(China)6 (0.1 mol L-1 KCl) define a linear analytical curve (r = 0.999) in the range of 5 x 10-7 to 1.0 x 10-3 mol L-1 for flow amperometry at a gold electrode potentiostated at 0.4 V versus Ag/AgCl. Methods for the amperometric μ-flow determination of promethazine (FIA like), dipyrone (SIA like) and chlorpromazine (DIA) in pharmaceutical formulations were developed and applied to real samples. Excellent linearity of analytical curves and high repeatability (R.S.D. < 3.0%) at the low picomole range was obtained and all results for real samples were in agreement with reference methods. The results reflect the stability and the reliability of the setups envisioned for the electronic pipette coupled with amperometric μ-cell and the validity of the μ-FA methods

  18. A four-organ-chip for interconnected long-term co-culture of human intestine, liver, skin and kidney equivalents.

    Science.gov (United States)

    Maschmeyer, Ilka; Lorenz, Alexandra K; Schimek, Katharina; Hasenberg, Tobias; Ramme, Anja P; Hübner, Juliane; Lindner, Marcus; Drewell, Christopher; Bauer, Sophie; Thomas, Alexander; Sambo, Naomia Sisoli; Sonntag, Frank; Lauster, Roland; Marx, Uwe

    2015-06-21

    Systemic absorption and metabolism of drugs in the small intestine, metabolism by the liver as well as excretion by the kidney are key determinants of efficacy and safety for therapeutic candidates. However, these systemic responses of applied substances lack in most in vitro assays. In this study, a microphysiological system maintaining the functionality of four organs over 28 days in co-culture has been established at a minute but standardized microsystem scale. Preformed human intestine and skin models have been integrated into the four-organ-chip on standard cell culture inserts at a size 100,000-fold smaller than their human counterpart organs. A 3D-based spheroid, equivalent to ten liver lobules, mimics liver function. Finally, a barrier segregating the media flow through the organs from fluids excreted by the kidney has been generated by a polymeric membrane covered by a monolayer of human proximal tubule epithelial cells. A peristaltic on-chip micropump ensures pulsatile media flow interconnecting the four tissue culture compartments through microfluidic channels. A second microfluidic circuit ensures drainage of the fluid excreted through the kidney epithelial cell layer. This four-organ-chip system assures near to physiological fluid-to-tissue ratios. In-depth metabolic and gene analysis revealed the establishment of reproducible homeostasis among the co-cultures within two to four days, sustainable over at least 28 days independent of the individual human cell line or tissue donor background used for each organ equivalent. Lastly, 3D imaging two-photon microscopy visualised details of spatiotemporal segregation of the two microfluidic flows by proximal tubule epithelia. To our knowledge, this study is the first approach to establish a system for in vitro microfluidic ADME profiling and repeated dose systemic toxicity testing of drug candidates over 28 days.

  19. An Atomic Force Microscope with Dual Actuation Capability for Biomolecular Experiments

    Science.gov (United States)

    Sevim, Semih; Shamsudhin, Naveen; Ozer, Sevil; Feng, Luying; Fakhraee, Arielle; Ergeneman, Olgaç; Pané, Salvador; Nelson, Bradley J.; Torun, Hamdi

    2016-06-01

    We report a modular atomic force microscope (AFM) design for biomolecular experiments. The AFM head uses readily available components and incorporates deflection-based optics and a piezotube-based cantilever actuator. Jetted-polymers have been used in the mechanical assembly, which allows rapid manufacturing. In addition, a FeCo-tipped electromagnet provides high-force cantilever actuation with vertical magnetic fields up to 0.55 T. Magnetic field calibration has been performed with a micro-hall sensor, which corresponds well with results from finite element magnetostatics simulations. An integrated force resolution of 1.82 and 2.98 pN, in air and in DI water, respectively was achieved in 1 kHz bandwidth with commercially available cantilevers made of Silicon Nitride. The controller and user interface are implemented on modular hardware to ensure scalability. The AFM can be operated in different modes, such as molecular pulling or force-clamp, by actuating the cantilever with the available actuators. The electromagnetic and piezoelectric actuation capabilities have been demonstrated in unbinding experiments of the biotin-streptavidin complex.

  20. Analysis and Test of Piezoelectric Micropump for Drug Delivery%微型药品输送压电泵的性能分析与试验研究

    Institute of Scientific and Technical Information of China (English)

    阚君武; 宣明; 杨志刚; 吴一辉; 吴博达; 程光明

    2005-01-01

    微系统(泵)给药易于控制药品释放速度,进而提高药物疗效.研制了一种微型薄膜阀压电驱动微型泵,适用于内置式或便携式药品输送系统.分析压电振子及阀片动态特性的影响因素,给出了薄膜阀片谐振频率的计算方法.分析结果表明,阀和压电振子的耦合作用决定了压电泵的输出特性,对于确定的压电振子,通过阀片设计可提高压电泵的最佳工作频率和输出能力.制作了阀片尺寸不同的两个微型压电泵,进行了对比试验.小阀片微型压电泵输出的能力及最佳工作频率较高,且有两个最佳工作频率段(800 Hz和3 000 Hz),输出流量和压力分别为3.5 ml/min和27 KPa;大阀片压电泵的输出能力和最佳工作频率相对较低,只有一个最佳工作频率点(200 Hz左右),输出流量和压力分别为3.0 ml/min和9.5 KPa.这说明通过阀片的设计可提高药用微型压电泵的最佳工作频率及输出能力、减小输出脉动,以往认为有阀压电泵只能在低频状态工作的观点是错误的.

  1. 无阀压电微泵用平面锥管内部流动附壁效应%Coanda effect of flat taper pipe applied in valveless piezoelectric micro-pump

    Institute of Scientific and Technical Information of China (English)

    何秀华; 朱学斌; 杨嵩; 邓志丹

    2015-01-01

    为研究锥管内流体流动中产生的附壁效应对其流阻系数的影响,采用数值模拟的方法对平面锥管内部流动附壁效应进行研究.结果表明:雷诺数Re在300~3000,锥管角度在5~40°时,扩散方向流动可以分为3种状态,即稳定状态、附壁状态和射流状态.锥管角度为10~35°时,锥管内流动易于发生附壁效应. Re在300~1 200时,稳定状态扩散流阻系数随着扩散角的增大迅速降低;附壁状态扩散流阻系数随着扩散角的增大缓慢增大;射流状态扩散流阻系数随着扩散角的增大而缓慢降低. Re在1 800~3 000时,附壁状态扩散流阻系数在锥管角度为30°时达到最大值.流阻系数比在稳定状态和射流状态下基本不变,在附壁状态下随着扩散角的增大迅速减小.%The impact of Coanda effect on the flow resistance coefficient of flat-walled diffusers has been studied by numerical simulation, and the results show that when Reynolds number changes in the range of 300~3 000 and the diffusion angleθof the cone tube varies from 5° to 40°, the fluid flow to the diffusion direction goes through three stages: the stable state, the wall-attachment state and the jet deflection state, when 10°<θ < 35°, the Coanda effect can be obtained easily. When Reynolds number ranging from 300 to 1 200, with the increasing of diffusion angle, the flow resistance coefficient decreases rapidly during the stable state, increases slowly among the wall-attachment state and decreases gradually in time of the jet deflection state. While Re varies from 1 800 to 3 000, the flow resistance coefficient of the wall-attachment state reaches maximum atθ = 30°. The flow resistance coefficient ratio in steady state and jet condition state is basically unchanged, but decreases quickly during the wall-attachment state with the increasing of diffusion angle.

  2. Assessment and in vitro Experiment of a Novel Implantable Artificial Anal Sphincter Prototype%新型原位植入式人工肛门括约肌样机及离体肠道实验研究

    Institute of Scientific and Technical Information of China (English)

    克磊; 颜国正; 翁晓靖; 刘华; 许茜茜

    2012-01-01

    In this paper an intelligent and remote-controlled artificial anal sphincter based on biological signal feedback mechanism for a novel artificial anal sphincter system ( AASS) was designed and integrated. The peristaltic mechanical medical micropump transported fluid bidirectional with a maximum flow rate of 8. 5 mL/min and built up backpressure up to 170 kPa. The design of the prosthesis reduced the occlusion pressure and allowed low inflation volumes (9 ~ 10.5 mL). The operating pressures between 3.34 and 7. 26 kPa indicated a minor risk of ischemic injury to the bowel. Furthermore, the operation time was estimated at about 2 days with rechargeable battery based on transcutaneous energy transfer technology. The results of in vitro experiments indicated that the system could control the fecal and build the sense of defecation successfully. This AASS is promising in application for the patients with severe anal dysfunction caused by fecal incontinence or colostomy.%设计一款基于生物信号反馈机制的智能化可遥控式人工肛门括约肌系统.所设计的蠕动式微型医用泵在3.3V驱动电压下,最大流量为8.5 mL/min,最大封闭压可达170 kPa.新型括约肌假体在较小注水量(9~10.5 mL)的情况下,可实现对肠壁作用压的均匀分布(3.34~7.26 kPa),符合人体肠道生理结构和安全压力阈值的要求,避免由于局部高压导致的缺血性坏死.人工括约肌系统采用体内充电电池、体外无线经皮能量充电的供电方式,实现系统的完全植入式移植.离体实验结果表明,该系统可以有效地抑制肠道内容物渗漏,成功建立排便感知信号,从而为严重肛门失禁、结肠造口等肛门功能严重缺失的患者提供一种人性化的治疗方案.

  3. Micromachined magnetohydrodynamic actuators and sensors

    Science.gov (United States)

    Lee, Abraham P.; Lemoff, Asuncion V.

    2000-01-01

    A magnetohydrodynamic (MHD) micropump and microsensor which utilizes micromachining to integrate the electrodes with microchannels and includes a magnet for producing magnetic fields perpendicular to both the electrical current direction and the fluid flow direction. The magnet can also be micromachined and integrated with the micropump using existing technology. The MHD micropump, for example, can generate continuous, reversible flow, with readily controllable flow rates. The flow can be reversed by either reversing the electrical current flow or reversing the magnetic field. By mismatching the electrodes, a swirling vortex flow can be generated for potential mixing applications. No moving parts are necessary and the dead volume is minimal. The micropumps can be placed at any position in a fluidic circuit and a combination of micropumps can generate fluidic plugs and valves.

  4. 不对称柔性壁管道内幂律流体蠕动传输的精确解%Exact Solution for Peristaltic Transport of Power-Law Fluid in an Asymmetric Channel With Compliant Walls

    Institute of Scientific and Technical Information of China (English)

    T·哈亚特; M·贾佛德1; 黄绍红

    2010-01-01

    在不对称管道内,研究了壁面柔曲性对非Newton流体蠕动流的影响.流变学性质由幂律流体本构方程表征.在数学表达中,采用了长波和低Reynolds数近似.得到了流函数和速度的精确解.给出了流线图及其俘获现象.对所讨论的流动,陈列了关键参数的显著特征,并最后给出了主要结论.

  5. Getting Started with PEAs-Based Flapping-Wing Mechanisms for Micro Aerial Systems

    Directory of Open Access Journals (Sweden)

    José Carlos Durán Hernández

    2016-05-01

    Full Text Available This paper introduces recent advances on flapping-wing Micro and Nano Aerial Vehicles (MAVs and NAVs based on Piezoelectric Actuators (PEA. Therefore, this work provides essential information to address the development of such bio-inspired aerial robots. PEA are commonly used in micro-robotics and precise positioning applications (e.g., micro-positioning and micro-manipulation, whereas within the Unmanned Aerial Vehicles (UAVs domain, motors are the classical actuators used for rotary or fixed-wing configurations. Therefore, we consider it pertinent to provide essential information regarding the modeling and control of piezoelectric cantilever actuators to accelerate early design and development stages of aerial microrobots based on flapping-wing systems. In addition, the equations describing the aerodynamic behavior of a flapping-wing configuration are presented.

  6. Mechanical behavior simulation of MEMS-based cantilever beam using COMSOL multiphysics

    Energy Technology Data Exchange (ETDEWEB)

    Acheli, A., E-mail: aacheli@cdta.dz; Serhane, R. [Centre de Développement des Technologies Avancées (CDTA). BP n°17 Baba Hassen, Alger (Algeria)

    2015-03-30

    This paper presents the studies of mechanical behavior of MEMS cantilever beam made of poly-silicon material, using the coupling of three application modes (plane strain, electrostatics and the moving mesh) of COMSOL Multi-physics software. The cantilevers playing a key role in Micro Electro-Mechanical Systems (MEMS) devices (switches, resonators, etc) working under potential shock. This is why they require actuation under predetermined conditions, such as electrostatic force or inertial force. In this paper, we present mechanical behavior of a cantilever actuated by an electrostatic force. In addition to the simplification of calculations, the weight of the cantilever was not taken into account. Different parameters like beam displacement, electrostatics force and stress over the beam have been calculated by finite element method after having defining the geometry, the material of the cantilever model (fixed at one of ends but is free to move otherwise) and his operational space.

  7. Modulated interaction in double-layer shape memory-based micro-designed actuators

    Science.gov (United States)

    Crăciunescu, Corneliu; Ercuta, Aurel

    2015-12-01

    The effect of superposed transitions in actuators with layered shape memory alloy (SMA) films undergoing martensitic phase transformation is analyzed in terms of a model developed for two layers of different composition, deposited at the same temperature on a substrate. A significant difference is observed in the actuation versus temperature relationship, depending on the thermal and elastic properties of the SMA layers and their martensitic transformation temperature. The prediction of the actuation is exemplified using a multilayer model and is verified for a cantilever actuator with NiTi and NiMnGa layers deposited on a Si substrate. The model sets the ground for a smart selection of SMAs in order to achieve a modulated actuation.

  8. Feedforward and output feedback control of a highly oscillating and nonlinear 2-DOF piezoelectric actuator by using input shaping compensator and a linear quadratic regulator

    Science.gov (United States)

    Al Hamidi, Yasser; Rakotondrabe, Micky

    2016-05-01

    This paper deals with the control of a two degrees of freedom (2-DOF) piezoelectric cantilever actuator which is characterized by badly damped oscillations, hysteresis nonlinearity and cross-couplings. First, a feedforward control scheme based on the zero placement technique is introduced to annihilate the oscillations. Then a disturbance observer and a disturbance compensator are introduced to reduce the effects of low frequencies phenomena (hysteresis and creep) which were approximated by a fictive disturbance. Finally an output feedback scheme based on the linear quadratic regulator is added in order to reduce the cross-couplings effects to improve the tracking performances, and eventually to add robustness. Experiments were carried out and confirm the predicted performances.

  9. Novel Versatile Intelligent Drug Delivery Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project will demonstrate and develop a novel micro-pump capable of controlled and selective chemical transport. Phase I will create, characterize, and...

  10. Topology optimisation of natural convection problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Aage, Niels; Andreasen, Casper Schousboe;

    2014-01-01

    This paper demonstrates the application of the density-based topology optimisation approach for the design of heat sinks and micropumps based on natural convection effects. The problems are modelled under the assumptions of steady-state laminar flow using the incompressible Navier-Stokes equations...... for designing heat sink geometries cooled by natural convection and micropumps powered by natural convection. Copyright © 2013 John Wiley & Sons, Ltd....

  11. Continuous micro liquid delivery by evaporation on a gradient-capillary microstructure surface

    International Nuclear Information System (INIS)

    An evaporation-based micropump is proposed and fabricated for delivering liquid with constant flow rates of ∼100 nl s−1 continuously. The liquid is pumped by the surface transpiration in a micro evaporator, which consists of a gradient-capillary surface by microfabricating micropost arrays. The micropost arrays are patterned such that the gaps between microposts reduce gradually away from the center microwell to the surface edge, by which a capillary force is formed to pull the liquid spreading on the evaporator surface. A simple analytical model is proposed to obtain the primary characteristics of the micropump, by which the influences of the contact angle of fluid on the flow rate and also the corresponding parameters during the operation of micropump are analyzed. The most striking feature of the micropump is that it can be precisely and simply controlled only by varying the surface wall temperature. The results indicate that a very linear relationship between the flow rate and solid wall temperature can be achieved by the present design. Quite consistent variation trend of the flow rate with wall temperature can be obtained between the experimental tests and theoretical analysis. The present micropump concept may be potentially used in delivering a precisely controlled, continuous flow rate for many new applications in the fields of biotechnology, environmental testing and instrumentation for analytical chemistry

  12. Intravenous fluid flow meter concept for zero gravity environment

    Science.gov (United States)

    Miller, C. G.

    1972-01-01

    Measuring chamber, included in infusion-set tubing, and peristaltic flow meter concept can be incorporated into flow meter that measures fluid flow rates between 100 and 600 cu cm per hour and at the same time maintains sterilization.

  13. Miniature ion-sorption vacuum pump with CNT field-emission electron source

    International Nuclear Information System (INIS)

    Generation and maintenance of the high vacuum in the MEMS-type (micro-electro-mechanical system) microsystems and vacuum nanoelectronics devices remain a major problem today. The phenomena of gas desorption from the surface of a microcavity and outgassing of materials limit the vacuum to the level of about 10−1 Pa. In this paper, a new MEMS-type micropump for generating a high vacuum in a microcavity is presented. The main component of the ion-sorption micropump is a carbon nanotube (CNT) field-emission electron source. Test structures of the electron source with electrophoretically deposited CNT have been fabricated and measured. A satisfactory value of the emission current and a low turn-on voltage have been obtained. The elaborated electron source has been applied to the micropump structure; it has enabled us to achieve a vacuum level below 10−3 Pa. (paper)

  14. System-in Package of Integrated Humidity Sensor Using CMOS-MEMS Technology.

    Science.gov (United States)

    Lee, Sung Pil

    2015-10-01

    Temperature/humidity microchips with micropump were fabricated using a CMOS-MEMS process and combined with ZigBee modules to implement a sensor system in package (SIP) for a ubiquitous sensor network (USN) and/or a wireless communication system. The current of a diode temperature sensor to temperature and a normalized current of FET humidity sensor to relative humidity showed linear characteristics, respectively, and the use of the micropump has enabled a faster response. A wireless reception module using the same protocol as that in transmission systems processed the received data within 10 m and showed temperature and humidity values in the display. PMID:26726359

  15. Three-dimensional study of a one-way, flexible magnetorheological elastomer-based micro fluid transport system

    Science.gov (United States)

    Behrooz, Majid; Gordaninejad, Faramarz

    2016-09-01

    This paper presents a three-dimensional study of a controllable flexible magnetically-activated micropump. The tubular micropump employs magnetically induced deformation of magnetorheological elastomer and one-way flexible conical valves for fluid transport. Three-dimensional magneto–fluid–solid interaction analysis is employed to investigate the performance of the system. The effects of key material, geometric, and magnetic parameters on the effectiveness of the system are examined. It is demonstrated that the proposed system can propel the fluid unidirectionally, and the volume of the transported fluid is significantly affected by some of the design parameters.

  16. System-in Package of Integrated Humidity Sensor Using CMOS-MEMS Technology.

    Science.gov (United States)

    Lee, Sung Pil

    2015-10-01

    Temperature/humidity microchips with micropump were fabricated using a CMOS-MEMS process and combined with ZigBee modules to implement a sensor system in package (SIP) for a ubiquitous sensor network (USN) and/or a wireless communication system. The current of a diode temperature sensor to temperature and a normalized current of FET humidity sensor to relative humidity showed linear characteristics, respectively, and the use of the micropump has enabled a faster response. A wireless reception module using the same protocol as that in transmission systems processed the received data within 10 m and showed temperature and humidity values in the display.

  17. Three-dimensional study of a one-way, flexible magnetorheological elastomer-based micro fluid transport system

    Science.gov (United States)

    Behrooz, Majid; Gordaninejad, Faramarz

    2016-09-01

    This paper presents a three-dimensional study of a controllable flexible magnetically-activated micropump. The tubular micropump employs magnetically induced deformation of magnetorheological elastomer and one-way flexible conical valves for fluid transport. Three-dimensional magneto-fluid-solid interaction analysis is employed to investigate the performance of the system. The effects of key material, geometric, and magnetic parameters on the effectiveness of the system are examined. It is demonstrated that the proposed system can propel the fluid unidirectionally, and the volume of the transported fluid is significantly affected by some of the design parameters.

  18. Design, modeling, and fabrication of piezoelectric polymer actuators

    Science.gov (United States)

    Fu, Yao; Harvey, Erol C.; Ghantasala, Muralidhar K.; Spinks, Geoff

    2004-04-01

    Piezoelectric polymers are a class of materials with great potential and promise for many applications. Because of their ideally suitable characteristics, they make good candidates for actuators. However, the difficulty of forming structures and shapes has limited the range of mechanical design. In this work, the design and fabrication of a unimorph piezoelectric cantilever actuator using piezoelectric polymer PVDF with an electroplated layer of nickel alloy has been described. The modeling and simulation of the composite cantilever with planar and microstructured surfaces has been performed by CoventorWare to optimize the design parameters in order to achieve large tip deflections. These simulation results indicated that a microstructured cantilever could produce 25 percent higher deflection compared to a simple planar cantilever surface. The tip deflection of the composite cantilever with a length of 6mm and a width of 1mm can reach up to 100μm. A PVDF polymer with a specifically designed shape was punched out along the elongation direction on the embossing machine at room temperature. The nickel alloy layer was electroplated on one side of the PVDF to form a composite cantilever. The tip deflection of the cantilever was observed and measured under an optical microscope. The experimental result is in agreement with the theoretical analysis.

  19. Biocompatible circuit-breaker chip for thermal management of biomedical microsystems

    Science.gov (United States)

    Luo, Yi; Dahmardeh, Masoud; Takahata, Kenichi

    2015-05-01

    This paper presents a thermoresponsive micro circuit breaker for biomedical applications specifically targeted at electronic intelligent implants. The circuit breaker is micromachined to have a shape-memory-alloy cantilever actuator as a normally closed temperature-sensitive switch to protect the device of interest from overheating, a critical safety feature for smart implants including those that are electrothermally driven with wireless micro heaters. The device is fabricated in a size of 1.5  ×  2.0  ×  0.46 mm3 using biocompatible materials and a chip-based titanium package, exhibiting a nominal cold-state resistance of 14 Ω. The breaker rapidly enters the full open condition when the chip temperature exceeds 63 °C, temporarily breaking the circuit of interest to lower its temperature until chip temperature drops to 51 °C, at which the breaker closes the circuit to allow current to flow through it again, physically limiting the maximum temperature of the circuit. This functionality is tested in combination with a wireless resonant heater powered by radio-frequency electromagnetic radiation, demonstrating self-regulation of heater temperature. The developed circuit-breaker chip operates in a fully passive manner that removes the need for active sensor and circuitry to achieve temperature regulation in a target device, contributing to the miniaturization of biomedical microsystems including electronic smart implants where thermal management is essential.

  20. A highly aromatic and sulfonated ionomer for high elastic modulus ionic polymer membrane micro-actuators

    International Nuclear Information System (INIS)

    A high modulus, sulfonated ionomer synthesized from 4,6-bis(4-hydroxyphenyl)-N,N-diphenyl-1,3,5-triazin-2-amine and 4,4′-biphenol with bis(4-fluorophenyl)sulfone (DPA-PS:BP) is investigated for ionic polymer actuators. The uniqueness of DPA-PS:BP is that it can have a high ionic liquid (IL) uptake and consequently generates a high intrinsic strain response, which is >1.1% under 1.6 V while maintaining a high elastic modulus (i.e. 600 MPa for 65 vol% IL uptake). Moreover, such a high modulus of the active ionomer, originating from the highly aromatic backbone and side-chain-free structure, allows for the fabrication of free-standing thin film micro-actuators (down to 5 µm thickness) via the solution cast method and focused-ion-beam milling, which exhibits a much higher bending actuation, i.e. 43 µm tip displacement and 180 kPa blocking stress for a 200 µm long and 5 µm thick cantilever actuator, compared with the ionic actuators based on traditional ionomers such as Nafion, which has a much lower elastic modulus (50 MPa) and actuation strain. (paper)

  1. Biocompatible circuit-breaker chip for thermal management of biomedical microsystems

    International Nuclear Information System (INIS)

    This paper presents a thermoresponsive micro circuit breaker for biomedical applications specifically targeted at electronic intelligent implants. The circuit breaker is micromachined to have a shape-memory-alloy cantilever actuator as a normally closed temperature-sensitive switch to protect the device of interest from overheating, a critical safety feature for smart implants including those that are electrothermally driven with wireless micro heaters. The device is fabricated in a size of 1.5  ×  2.0  ×  0.46 mm3 using biocompatible materials and a chip-based titanium package, exhibiting a nominal cold-state resistance of 14 Ω. The breaker rapidly enters the full open condition when the chip temperature exceeds 63 °C, temporarily breaking the circuit of interest to lower its temperature until chip temperature drops to 51 °C, at which the breaker closes the circuit to allow current to flow through it again, physically limiting the maximum temperature of the circuit. This functionality is tested in combination with a wireless resonant heater powered by radio-frequency electromagnetic radiation, demonstrating self-regulation of heater temperature. The developed circuit-breaker chip operates in a fully passive manner that removes the need for active sensor and circuitry to achieve temperature regulation in a target device, contributing to the miniaturization of biomedical microsystems including electronic smart implants where thermal management is essential. (paper)

  2. Pin count-aware biochemical application compilation for mVLSI biochips

    DEFF Research Database (Denmark)

    Lander Raagaard, Michael; Pop, Paul

    2015-01-01

    are controlled from external pressure sources, connected to “control pins”. By combining several microvalves, more complex units, such as micropumps, switches, mixers, and multiplexers, can be built. The current practice is to design these biochips by hand in drawing tools such as AutoCAD, and to program them...

  3. PAIN RELIEF MEDIATED BY IMPLANTABLE DRUG-DELIVERY DEVICES

    NARCIS (Netherlands)

    HOEKSTRA, A

    1994-01-01

    Various totally implantable drug delivery systems from single access ports to micropumps are now available for administration of repeated boluses, and continuous or programmable infusions. In this respect, emphasis is given to a relatively cheap, totally implantable system for self-administering int

  4. Microfluidic "blinking" bubble pump

    NARCIS (Netherlands)

    Yin, Zhizhong; Prosperetti, Andrea

    2005-01-01

    The paper reports data obtained on a simple micropump, suitable for electrolytes, based on the periodic growth and collapse of a single vapor bubble in a microchannel. With a channel diameter of the order of 100 µm, pumping rates of several tens of µl/min and pressure differences of several kPa are

  5. The maximum life expectancy for a micro-fabricated diaphragm

    Science.gov (United States)

    Cǎlimǎnescu, Ioan; Stan, Liviu-Constantin; Popa, Viorica

    2015-02-01

    Micro-fabricated diaphragms can be used to provide pumping action in microvalve and microfluidic applications. The functionality of the microdiaphragm in a wirelessly actuated micropump plays a major role in low-powered device actuation. In developing micropumps and their components, it is becoming an increasing trend to predict the performance before the prototype is fabricated. Because performance prediction allows for an accurate estimation of yield and lifetime, in addition to developing better understanding of the device while taking into account the details of the device structure and second order effects. Hence avoid potential pitfalls in the device operation in a practical environment. The goal of this research is to determine via FEA the life expectancy for a corrugated circular diaphragm made out of an aluminum alloy. The geometry of the diaphragm is given below being generated within SolidWorks 2010, all the calculations were made using Ansys 13TM . The sound design of a micropump is heavily depending on the lifetime expectancy of the working part of the device which is the diaphragm. This will be subjected on cyclic loading and the fatigue will limit the life of this part. Once the diaphragm is breaking, the micropump is no more able to fulfill its scope. Any micropump manufacturer will then be very concerned on the life expectancy from the fatigue point of view of the diaphragms. The diaphragm circular and corrugated and made of Al alloy, showed a very good behavior from the fatigue point of view, the maximum life expectancy being 1.9 years of continuous functioning with 100 cycles per second. This work showed an simple and forward application of FEA analysis methods in order to estimate the fatigue behavior of corrugated circular microdiaphragms.

  6. Development of wearable medical device for Bio-MEMS

    Science.gov (United States)

    Nakanishi, Naoyuki; Yamamoto, Hidetake; Tsuchiya, Kazuyoshi; Uetsuji, Yasutomo; Nakamachi, Eiji

    2006-01-01

    Biomedical Micro Electro Mechanical Systems (Bio-MEMS) have been applied to the development of a variety of health care related products including health Monitoring Systems (HMS) and Drug Delivery Systems (DDS). We focus on research to develop the new type compact medical device used for blood sugar control. The new type compact medical device comprises (1) a micropump system to extract blood using a pressure change occurred by electrolysis, (2) a platinum (Pt) electrode as a blood sugar sensor immobilized Glucose Oxidase (GOx) and attached to the gate electrode of Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) to detect the amount of glucose in extracted blood, and (3) a micropump system to inject insulin using a pressure change occurred by electrolysis. The device can extract blood in a few microliter through a painless microneedle with the micropump, which used the pressure change occurred by electrolysis. The liquid extraction ability of the micropump system through a microneedle, which is 3.8 mm in length and 100 μm in internal diameter, was measured. The wearable medical device with using the micropump controlled by electrolysis could extract human blood at the speed of 0.15 μl/sec. If the wearable medical device extracts human blood for 6 seconds, it is enough human blood volume to measure a glucose level, compared to the amount of commercial based glucose level monitor. The compact medical device with the air bubble that occurred by electrolysis could inject insulin at the speed of 6.15μl/sec.

  7. Microfluidic pumping, routing and metering by contactless metal-based electro-osmosis.

    Science.gov (United States)

    Fu, Xiaotong; Mavrogiannis, Nicholas; Doria, Steven; Gagnon, Zachary

    2015-09-01

    Over the past decade, many microfluidic platforms for fluid processing have been developed in order to perform on-chip fluidic manipulations. Many of these methods, however, require expensive and bulky external supporting equipment, which are not typically applicable for microsystems requiring portability. We have developed a new type of portable contactless metal electro-osmotic micropump capable of on-chip fluid pumping, routing and metering. The pump operates using two pairs of gallium metal electrodes, which are activated using an external voltage source, and separated from a main flow channel by a thin micron-scale PDMS membrane. The thin contactless membrane allows for field penetration and electro-osmotic (EO) flow within the microchannel, but eliminates electrode damage and sample contamination commonly associated with traditional DC electro-osmotic pumps that utilize electrodes in direct contact with the working fluid. The maximum flow rates and pressures generated by the pump using DI water as a working buffer are 10 nL min(-1) and 30 Pa, respectively. With our current design, the maximum operational conductivity where fluid flow is observed is 0.1 mS cm(-1). Due to the small size and simple fabrication procedure, multiple micropump units can be integrated into a single microfluidic device for automated on-chip routing and sample metering applications. We experimentally demonstrated the ability to quantify micropump electro-osmotic flowrate and pressure as a function of applied voltage, and developed a mathematical model capable of predicting the performance of a contactless micropump for a given external load and internal hydrodynamic microchannel resistance. Finally, we showed that by activating specific pumps within a microchannel network, our micropumps are capable of routing microchannel fluid flow and generating plugs of solute. PMID:26053965

  8. Stimuli-responsive cylindrical hydrogels mimic intestinal peristalsis to propel a solid object.

    Science.gov (United States)

    Nistor, V; Cannell, J; Gregory, J; Yeghiazarian, L

    2016-04-21

    The emerging field of soft robotics relies on soft, stimuli-responsive materials to enable load transport, manipulation, and mobility in complex unconstrained environments. These materials often need to replicate biological functionality such as muscle contractions and flexibility. Here we demonstrate a soft actuator prototype based on thermosensitive PNIPAAM hydrogels that can transport and manipulate objects. A hollow cylindrical hydrogel was selectively heated and cooled with Peltier devices to yield a traveling wave of shrinking and swelling akin to intestinal peristalsis. A 4 mm diameter bead was placed inside the cylinder and propelled 19.5 mm, equal to distance traveled by the peristaltic wave. We derived conditions that enable peristaltic transport as a function of transporter-cargo design parameters. We conclude that hydrogel-based peristaltic manipulators covering 2 orders of magnitude in stiffness (1-10(2) kPa) could transport cargo spanning 4 orders of magnitude in size (μm-m).

  9. Stimuli-responsive cylindrical hydrogels mimic intestinal peristalsis to propel a solid object.

    Science.gov (United States)

    Nistor, V; Cannell, J; Gregory, J; Yeghiazarian, L

    2016-04-21

    The emerging field of soft robotics relies on soft, stimuli-responsive materials to enable load transport, manipulation, and mobility in complex unconstrained environments. These materials often need to replicate biological functionality such as muscle contractions and flexibility. Here we demonstrate a soft actuator prototype based on thermosensitive PNIPAAM hydrogels that can transport and manipulate objects. A hollow cylindrical hydrogel was selectively heated and cooled with Peltier devices to yield a traveling wave of shrinking and swelling akin to intestinal peristalsis. A 4 mm diameter bead was placed inside the cylinder and propelled 19.5 mm, equal to distance traveled by the peristaltic wave. We derived conditions that enable peristaltic transport as a function of transporter-cargo design parameters. We conclude that hydrogel-based peristaltic manipulators covering 2 orders of magnitude in stiffness (1-10(2) kPa) could transport cargo spanning 4 orders of magnitude in size (μm-m). PMID:26971454

  10. Physiological breakdown of Jeffrey six constant nanofluid flow in an endoscope with nonuniform wall

    Directory of Open Access Journals (Sweden)

    S. Nadeem

    2015-12-01

    Full Text Available This paper analyse the endoscopic effects of peristaltic nanofluid flow of Jeffrey six-constant fluid model in the presence of magnetohydrodynamics flow. The current problem is modeled in the cylindrical coordinate system and exact solutions are managed (where possible under low Reynolds number and long wave length approximation. The influence of emerging parameters on temperature and velocity profile are discussed graphically. The velocity equation is solved analytically by utilizing the homotopy perturbation technique strongly, while the exact solutions are computed from temperature equation. The obtained expressions for velocity , concentration and temperature is sketched during graphs and the collision of assorted parameters is evaluate for transform peristaltic waves. The solution depend on thermophoresis number Nt, local nanoparticles Grashof number Gr, and Brownian motion number Nb. The obtained expressions for the velocity, temperature, and nanoparticles concentration profiles are plotted and the impact of various physical parameters are investigated for different peristaltic waves.

  11. Instrumental modification intended to save time, and volumes of sample and reagent solutions, in the atomic fluorescence spectrometric determination of mercury.

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martínez-Sánchez, María J; García-Lorenzo, Mariluz; López-García, Ignacio; Hernández-Córdoba, Manuel

    2007-05-01

    Use of small membrane pumps, instead of peristaltic pumps, to introduce sample and reagent solutions into the spectrometer has several advantages in atomic fluorescence spectrometric determination of mercury. This simple modification results in a substantial saving in the time required for the measurements and so 90% of reagent solution volumes and 95% of sample solution volumes are saved, with a consequent decrease in the volume of waste generated. The sampling frequency is almost tripled, with no deterioration in sensitivity, which is similar to that obtained by use of peristaltic pumps. The relative standard deviation for ten consecutive measurements of a 1 microg L-1 mercury solution was approximately 2%. PMID:17351707

  12. Tissue engineering for neuromuscular disorders of the gastrointestinal tract

    Institute of Scientific and Technical Information of China (English)

    Kenneth L Koch; Khalil N Bitar; John E Fortunato

    2012-01-01

    The digestive tract is designed for the optimal processing of food that nourishes all organ systems.The esophagus,stomach,small bowel,and colon are sophisticated neuromuscular tubes with specialized sphincters that transport ingested food-stuffs from one region to another.Peristaltic contractions move ingested solids and liquids from the esophagus into the stomach; the stomach mixes the ingested nutrients into chyme and empties chyme from the stomach into the duodenum.The to-and-fro movement of the small bowel maximizes absorption of fat,protein,and carbohydrates.Peristaltic contractions are necessary for colon function and defecation.

  13. Vibration energy harvesting in railway tunnels with a wireless sensor node application

    Energy Technology Data Exchange (ETDEWEB)

    Wischke, Martin

    2012-07-01

    Vibration harvesting is a promising concept to prolong the lifetime of batterypowered stand-alone systems, or even to enable their energy-autonomy. This thesis focuses on ambient vibrations converted by electromechanical transducers into electricity. The final goal is energy scavenging from train-induced vibrations in railway tunnels. This is achieved via the development of a suitable harvester for this environment and the practical demonstration of a vibrationpowered wireless sensor node (WSN). At the beginning of this thesis, extensive vibration measurements were performed in several traffic tunnels. The obtained unique data set formed the basis for the design and test of several harvesters. The railway sleeper was chosen as usable harvester location. A shock-resistant double-side suspended piezoelectric cantilever was developed. Several cantilevers with different eigenfrequencies are combined in an array, creating a robust harvester with a broad bandwidth. A field test of 7 days in the Loetschbergbasis-tunnel verified that, on average the sufficient energy for powering a virtual wireless sensor node was scavenged. For application in a real WSN, the harvester array was scaled up to 10 cantilevers. The power management for the sensor node was developed concurrently. The central component is a power switch that monitors the energy level in the system's storage capacitor and only triggers the wireless interface when sufficient energy is available. Combined with a train detection circuit, the presented energy-autonomous WSN reliably reports every passing vehicle. In addition to the development of an energy-autonomous fully integrated WSN, this work investigates nonlinear properties of PZT ceramics. Consideration of the elastostriction and the electrostriction enables a more precises prediction of the tip displacement of a piezoelectric cantilever actuator. Further, the elastostriction is exploited to modify the resonance frequency of a bimorph cantilever. Basing

  14. Design and characterisation of micro-diaphragm for low power drug delivery applications

    Science.gov (United States)

    Dissanayake, Don W.; Al-Sarawi, Said F.; Lu, Tien-Fu; Abbott, Derek

    2008-03-01

    Micro-fabricated diaphragms can be used to provide pumping action in microvalve and microfluidic applications. In this paper, a design for a micro-diaphragm that features low power and small area is presented. The diaphragm is actuated using a Surface Acoustic Wave (SAW) device that is interrogated from an RF signal to provide secure actuation operation. The micropump is targeted for in vivo nano-scale drug delivery and similar applications. For low power micropump operation, it is important to design the diaphragm with a higher flexibility while maintaining the stability. Analysis is carried out using ANSYS simulation tools with different design methods and materials. Results achieved from analytical and Finite Element Modeling (FEM) methods are compared and discussed to decide on optimal dimensions for the diaphragm.

  15. A valveless micro impedance pump driven by electromagnetic actuation

    OpenAIRE

    Rinderknecht, Derek; Hickerson, Anna Iwaniec; Gharib, Morteza

    2005-01-01

    Over the past two decades, a variety of micropumps have been explored for various applications in microfluidics such as control of pico- and nanoliter flows for drug delivery as well as chemical mixing and analysis. We present the fabrication and preliminary experimental studies of flow performance on the micro impedance pump, a previously unexplored method of pumping fluid on the microscale. The micro impedance pump was constructed of a simple thin-walled tube coupled at either end to glass ...

  16. Integrated micro-liquid dosing systems

    OpenAIRE

    Theo S.J. Lammerink; Elwenspoek, Miko; Fluitman, Jan H.J

    1993-01-01

    An integrated micro-liquid dosing system consisting of a micropump and a microliquid flow sensor is demonstrated. The dosing system allows accurate dosing of liquid in the microliter regime and can easily be integrated with components such as mixers and detectors in micro-liquid handling systems. The liquid pump is of the reciprocating type with a thermopneumatic actuator. The microliquid flow sensor is based on the thermal anemometer type. Both pump and flow sensor are realized in a 3-in (10...

  17. Experience with structural elements for controlling flow of radioactive and corrosive liquids

    International Nuclear Information System (INIS)

    A description is presented of manually operated cocks 2 mm in inner diameter, electromagnetic valves, tube bushings and plastic tube bushings, elements for joining tubes, a six-throw diaphragm pump with a separate delivery head, and micropumps. Operating experience is reported. The equipment described comprises the basic elements for the construction of laboratory facilities where corrosion or radioactive gases and liquids are handled. (J.P.)

  18. Performances analysis of a piezo-pump

    OpenAIRE

    Belkhiat S.; Benaissa A.

    2012-01-01

    Piezo-pumps, in the last decade, have received extensive attention because of their potential applications in biomedical devices, biological and chemical analysis, micro-electronics cooling and space exploration. In this paper an analytical model is developed to analysis the parameters effect on the pump flow. The micro-pump driven by piezostack (PZT alloy multilayer) as actuator is studied as function size and working middle. This one is compared with SCMCP pump actuated by PZT alloy as piez...

  19. Modeling and Simulation Framework for Flow-Based Microfluidic Biochips

    DEFF Research Database (Denmark)

    Schmidt, Morten Foged; Minhass, Wajid Hassan; Pop, Paul;

    2013-01-01

    several microvalves, more complex units, such as micropumps, switches, mixers, and multiplexers, can be built. Such biochips are becoming increasingly complex, with thousands of components, but are still designed manually using a bottom-up full-custom design approach, which is extremely labor intensive...... developed for the top-down design of flow-based biochips. We show how the IDE can be used to design biochips for several applications....

  20. Design, characterization, and modeling of microcirculation systems with integrated oxygenators

    OpenAIRE

    Busek, Mathias; Gruenzner, Stefan; Steege, Tobias; Schmieder, Florian; Klotzbach, Udo; Sonntag, Frank

    2016-01-01

    Here, we describe a microfluidic system for hypoxia assays on human cell culture models. These systems are developed to replace or reduce animal testing in biomedical basic research. The presented system uses a gas-permeable membrane as a gas–liquid interface and a micropump for media actuation to influence the oxygen content in two cell culture chambers. To apply well-defined hypoxic conditions to the cells, a good understanding of the mass transport phenomena is necessary....

  1. A novel monolithic microactuator fabricated by 3D rapid direct manufacture

    OpenAIRE

    King, Philip; Covington, James

    2009-01-01

    In this paper we present the world’s first micropump entirely fabricated using a 3D direct manufacture process based on microstereolithography. The device employs a single pneumatically actuated membrane, with flow rectification provided by a nozzle/diffuser arrangement. A maximum flow rate of just over 2,000 ?l/min was achieved with a pneumatic pressure of 2 PSIG and a stroke rate of 96 Hz. The fabrication of actuator components using stereolithography apparatus (SLA) is a potentially major ...

  2. A novel miniature dynamic microfluidic cell culture platform using electro-osmosis diode pumping

    OpenAIRE

    Chang, Jen-Yung; Wang, Shuo; Allen, Jeffrey S.; Lee, Seong Hyuk; Chang, Suk Tai; Choi, Young-Ki; Friedrich, Craig; Choi, Chang Kyoung

    2014-01-01

    An electro-osmosis (EOS) diode pumping platform capable of culturing cells in fluidic cellular micro-environments particularly at low volume flow rates has been developed. Diode pumps have been shown to be a viable alternative to mechanically driven pumps. Typically electrokinetic micro-pumps were limited to low-concentration solutions (≤10 mM). In our approach, surface mount diodes were embedded along the sidewalls of a microchannel to rectify externally applied alternating current into puls...

  3. On-line monitoring of Glucose and penicillin by sequential injection analysis

    DEFF Research Database (Denmark)

    Min, R.W.; Nielsen, Jens Bredal; Villadsen, John

    1996-01-01

    A sequential injection analysis (SIA) system has been developed for on-line monitoring of glucose and penicillin during cultivations of the filamentous fungus Penicillium chrysogenum. The SIA system consists of a peristaltic pump, an injection valve, two piston pumps, two multi-position valves...

  4. Effect of esophageal emptying and saliva on clearance of acid from the esophagus

    International Nuclear Information System (INIS)

    The clearance of acid from the esophagus and esophageal emptying in normal subjects was studied. A 15-ml bolus of 0.1 N hydrochloric acid (pH 1.2) radiolabeled with [/sup 99m/Tc]sulfur colloid was injected into the esophagus, and the subject swallowed every 30 seconds. Concurrent manometry and radionuclide imaging showed nearly complete emptying of acid from the esophagus by an immediate secondary peristaltic sequence, although esophageal pH did not rise until the first swallow 30 seconds later. Esophageal pH then returned to normal by a series of step increases, each associated with a swallow-induced peristaltic sequence. Saliva stimulation by an oral lozenge shortened the time required for acid clearance, whereas aspiration of saliva from the mouth abolished acid clearance. Saliva stimulation or aspiration did not affect the virtually complete emptying of acid volume by the initial peristaltic sequence. It was concluded that esophageal acid clearance normally occurs as a two-step process: (1) Virtually all acid volume is emptied from the esophagus by one or two peristaltic sequences, leaving a minimal residual amount that sustains a low pH, and (2) residual acid is neutralized by swallowed saliva

  5. Protein interactions at the heart of cardiac chamber formation

    NARCIS (Netherlands)

    C.J.J. Boogerd; A.F.M. Moorman; P. Barnett

    2009-01-01

    The vertebrate heart is a muscular pump that contracts in a rhythmic fashion to propel the blood through the body. During evolution, the morphologically complex four-chambered heart of birds and mammals has evolved from a single-layered tube with peristaltic contractility. The heart of Drosophila, r

  6. Long wavelength flow analysis in a curved channel

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Nasir [Dept. of Mathematics, International Islamic Univ., Islamabad (Pakistan); Sajid, Muhammad [Theoretical Plasma Physics Div., PINSTECH, P.O. Nilore, Islamabad (Pakistan); Hayat, Tasawar [Dept. of Mathematics, Quaid-i-Azam Univ., Islamabad (Pakistan)

    2010-03-15

    This study is concerned with the peristaltic flow of a viscous fluid in a curved channel. Mathematically the problem is governed by two partial differential equations. Closed form solutions of the stream function, axial velocity, and pressure gradient are developed under long wavelength and low Reynolds number assumptions. The influence of curvature is analyzed on various flow quantities of interest. (orig.)

  7. Application of a dynamic in vitro gastrointestinal tract model to study the availability of food mutagens, using heterocyclic aromatic amines as model compounds

    NARCIS (Netherlands)

    Krul, C.A.M.; Luiten-Schuite, A.; Baan, R.; Verhagen, H.; Mohn, G.; Feron, V.; Havenaar, R.

    2000-01-01

    The TNO gastro-Intestinal tract Model (TIM) is a dynamic computer-controlled in vitro system that mimics the human physiological conditions in the stomach and small intestine. In the current TIM physiological parameters such as pH, temperature, peristaltic movements, secretion of digestion enzymes,

  8. MR urography (MRU of non-dilated ureter with diuretic administration: Static fluid 2D FSE T2-weighted versus 3D gadolinium T1-weighted GE excretory MR

    Directory of Open Access Journals (Sweden)

    C. Roy

    2014-01-01

    Conclusion: T2-weighted MRU with multiple orientations and diuretic is sufficient to identify the non-dilated ureter. It offers information on ureteral peristaltism. It can be suggested that this sequence is able to detect an initial obstruction before hydronephrosis occurs.

  9. Pharmacologic Agents for Chronic Diarrhea

    OpenAIRE

    Lee, Kwang Jae

    2015-01-01

    Chronic diarrhea is usually associated with a number of non-infectious causes. When definitive treatment is unavailable, symptomatic drug therapy is indicated. Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents. Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reductio...

  10. Continuous venovenous haemodialysis

    DEFF Research Database (Denmark)

    Bistrup, C; Pedersen, R S; Jensen, Dorte Møller

    1996-01-01

    A simple three-pump-based system for the performance of continuous venovenous haemodialysis is described. The method employs access to the circulation via a double-lumen catheter, and by means of a standard extracorporeal peristaltic pump the blood is circulated through a haemofiltration filter. ...

  11. Gastric pH distribution and mixing of soft and rigid food particles in the stomach using a dual-marker technique

    Science.gov (United States)

    Mixing of a particle-laden material during peristaltic flow in the stomach has not been quantified in vivo. Gastric mixing plays a key role in the overall gastric digestion process; it determines the availability of acid and enzymes to individual solid food particles and controls the length of time ...

  12. High-speed pulsed mixing in a short distance with high-frequency switching of pumping from three inlets

    Science.gov (United States)

    Sugano, K.; Nakata, A.; Tsuchiya, T.; Tabata, O.

    2015-08-01

    In this study, we propose a mixing method using alternate pulsed flows from three inlets with flow direction control. In conventional pulsed mixing, a residual flow near the sidewalls inhibits the rapid mixing of two solutions at high switching frequency. In this study, we addressed this issue in order to perform rapid mixing in a short distance with a low Reynolds number. We fabricated a microfluidic mixing device consisting of a cross-shaped mixing channel with three inlet microchannels and three valveless micropumps. In conventional T-shaped or Y-shaped mixing channels, a residual flow is observed because of the incomplete switching of solutions. The three inlet configuration enabled us to split the residual flow at a switching frequency of pumping of up to 200 Hz, thus resulting in rapid mixing. Furthermore, by controlling the flow direction at the confluent area using the reverse flow of the micropump, the mixing speed was dramatically increased because of the complete switching of the two solutions. As a result, we achieved the mixing time of 3.6 ms and the mixing length of 20.7 µm, which were necessary to achieve a 90% mixing ratio at a high micropump switching frequency of 400 Hz and reverse flow ratio of 1/4.

  13. A microfluidic pump/valve inspired by xylem embolism and transpiration in plants.

    Directory of Open Access Journals (Sweden)

    Li Jingmin

    Full Text Available In plants, transpiration draws the water upward from the roots to the leaves. However, this flow can be blocked by air bubbles in the xylem conduits, which is called xylem embolism. In this research, we present the design of a biomimetic microfluidic pump/valve based on water transpiration and xylem embolism. This micropump/valve is mainly composed of three parts: the first is a silicon sheet with an array of slit-like micropores to mimic the stomata in a plant leaf; the second is a piece of agarose gel to mimic the mesophyll cells in the sub-cavities of a stoma; the third is a micro-heater which is used to mimic the xylem embolism and its self-repairing. The solution in the microchannels of a microfluidic chip can be driven by the biomimetic "leaf" composed of the silicon sheet and the agarose gel. The halting and flowing of the solution is controlled by the micro-heater. Results have shown that a steady flow rate of 1.12 µl/min can be obtained by using this micropump/valve. The time interval between the turning on/off of the micro-heater and the halt (or flow of the fluid is only 2∼3 s. This micropump/valve can be used as a "plug and play" fluid-driven unit. It has the potential to be used in many application fields.

  14. High-speed pulsed mixing in a short distance with high-frequency switching of pumping from three inlets

    International Nuclear Information System (INIS)

    In this study, we propose a mixing method using alternate pulsed flows from three inlets with flow direction control. In conventional pulsed mixing, a residual flow near the sidewalls inhibits the rapid mixing of two solutions at high switching frequency. In this study, we addressed this issue in order to perform rapid mixing in a short distance with a low Reynolds number. We fabricated a microfluidic mixing device consisting of a cross-shaped mixing channel with three inlet microchannels and three valveless micropumps. In conventional T-shaped or Y-shaped mixing channels, a residual flow is observed because of the incomplete switching of solutions. The three inlet configuration enabled us to split the residual flow at a switching frequency of pumping of up to 200 Hz, thus resulting in rapid mixing. Furthermore, by controlling the flow direction at the confluent area using the reverse flow of the micropump, the mixing speed was dramatically increased because of the complete switching of the two solutions. As a result, we achieved the mixing time of 3.6 ms and the mixing length of 20.7 µm, which were necessary to achieve a 90% mixing ratio at a high micropump switching frequency of 400 Hz and reverse flow ratio of 1/4. (paper)

  15. Effect of mixing on reaction-diffusion kinetics for protein hydrogel-based microchips.

    Science.gov (United States)

    Zubtsov, D A; Ivanov, S M; Rubina, A Yu; Dementieva, E I; Chechetkin, V R; Zasedatelev, A S

    2006-03-01

    Protein hydrogel-based microchips are being developed for high-throughput evaluation of the concentrations and activities of various proteins. To shorten the time of analysis, the reaction-diffusion kinetics on gel microchips should be accelerated. Here we present the results of the experimental and theoretical analysis of the reaction-diffusion kinetics enforced by mixing with peristaltic pump. The experiments were carried out on gel-based protein microchips with immobilized antibodies under the conditions utilized for on-chip immunoassay. The dependence of fluorescence signals at saturation and corresponding saturation times on the concentrations of immobilized antibodies and antigen in solution proved to be in good agreement with theoretical predictions. It is shown that the enhancement of transport with peristaltic pump results in more than five-fold acceleration of binding kinetics. Our results suggest useful criteria for the optimal conditions for assays on gel microchips to balance high sensitivity and rapid fluorescence saturation kinetics.

  16. Second sound in bursting freely suspended smectic-A films.

    Science.gov (United States)

    Müller, Frank; Bohley, Christian; Stannarius, Ralf

    2009-04-01

    We describe the bursting of macroscopic spherical bubbles formed by smectic liquid crystals. During rupture, strong light scattering is observed. It is suggested here that peristaltic undulations of the films are responsible for this scattering. This phenomenon distinguishes bursting smectic films from bursting soap films. The dynamics of these mechanical waves are strongly influenced by the internal layered structure of the smectic films, viz. by the elasticity of the molecular layers, expressed by the smectic layer compression modulus B. We study experimentally the optical properties of bursting smectic films by means of optical transmission measurements and laser scattering. The typical wavelength range of the propagating peristaltic waves is in the micrometer range. The wavelength spectrum rather is independent of the initial film thickness delta, but the scattering intensity strongly depends on delta. PMID:19518341

  17. A kinematic study of pulsation in the dorsal blood vessel of the blackworm, Lumbriculus variegatus

    Directory of Open Access Journals (Sweden)

    Kameko Halfmann

    2011-01-01

    Full Text Available The aquatic oligochaete Lumbriculus variegatus has a segmented, dorsal blood vessel (DBV that acts as a peristaltic pump to move blood through the animal's closed circulatory system. We conducted a kinematic study using videography and computational modeling as a first step toward understanding the control of DBV pulsation. Results suggested that pulse rates were highest in the posterior segments, while interpulse intervals and intersegmental delays were longest in the midbody segments. Differences in the interpulse interval distributions across regions suggest that some peristaltic waves initiated in the posterior segments do not propagate all the way to the anterior segments. A simple model consisting of a chain of excitable neuromuscular units replicated these kinetics. This model may be useful in future research aimed at understanding the modulatory effect of biogenic amines on peristalsis of the DBV. Moreover, research into the mechanisms of peristalsis of the DBV may lead to insights into disorders of peristalsis in human and veterinary medicine

  18. The role of prostaglandines in peristalsis of the human colon.

    Science.gov (United States)

    Bruch, H P; Schmidt, E; Laven, R; Kehrer, G; Wasner, K H

    1978-08-01

    Prostaglandines (PG) of the E and F series cause peristaltic activity in isolated longitudinal muscle strips of the human colon. As this phasic motor reaction can be varied by acetyl choline and adrenaline it was supposed, that prostaglandines contribute to peristalsis. The role of PG E and F in the human colon was studied by inhibiting the prostaglandine synthesis and by antagonizing the prostaglandine-effects. Indomethacin proved to be a suitable inhibitor. HR 546 was found a powerful antagonist. The effect of Pentagastrin and Cholecystokinin (CCK) on peristaltic activity were suppressed by Indomethacin and HR 546. The inhibition of peristalsis by Indomethacin and HR 546 was removed by high doses of PG E and F. On the basis of these results the role of PG for the motility of the gut is discussed.

  19. Study of the Gastric Emptying in Humans: Biomagnetic Assessments

    Science.gov (United States)

    Hernández, E.; Córdova, T.; Huerta-Franco, R.; Sosa, M.; Vargas-Luna, M.

    2006-09-01

    Biomagnetic studies of the gastrointestinal system can be carried out in two ways. Recording the magnetic field produced by the myenteric nervous system or created by any oral contrast mean as magnetic tracers or markers. In the first case, a SQUID magnetometer is demanded while a fluxgate magnetometer is enough in the second case. In this work, a magnetic marker was ingested by 8 healthy volunteers, in three gastric volume conditions, to measure the luminal content volume effect in the gastric emptying and to perform the quantification of the peristaltic frequencies in gastric and duodenum tract segments. The average emptying times for low luminal content, relative to the emptying time when the intake was the highest, were 43.6 ± 15.6 % and 77.3 ± 47.0 %. These results show that the biomagnetic technique is a powerful modality to estimate the effects of the gastric volume in the gastric emptying and a way to record the peristaltic frequencies.

  20. A mathematical model of motorneuron dynamics in the heartbeat of the leech

    Science.gov (United States)

    Buono, Pietro-Luciano; Palacios, A.

    2004-02-01

    The heartbeat of the medicinal leech is driven by direct contact between two arrays of motorneurons and two lateral blood vessels. At any given time, motorneurons exhibit one of two alternating states so that, on one side of the animal, the heart beats in a rear-to-front fashion (peristaltic), while on the other side the heart beats synchronously. Every 20 heartbeats, approximately, the two sides switch modes. It is known that the heartbeat rhythm is generated through burst of oscillatory activity produced by a central pattern generator (CPG) network of neurons. However, to the best of our knowledge, how the CPG activity is translated into peristaltic and synchronous rhythms in the motorneurons is yet unknown. In this work, we use symmetric systems of differential equations, accompanied with computational simulations, to investigate possible mechanisms for generating the motorneuron activity that characterizes the heartbeat of leeches and in particular the switching scenario.

  1. Slime mould electronic oscillators

    OpenAIRE

    Adamatzky, Andrew

    2014-01-01

    We construct electronic oscillator from acellular slime mould Physarum polycephalum. The slime mould oscillator is made of two electrodes connected by a protoplasmic tube of the living slime mould. A protoplasmic tube has an average resistance of 3~MOhm. The tube's resistance is changing over time due to peristaltic contractile activity of the tube. The resistance of the protoplasmic tube oscillates with average period of 73~sec and average amplitude of 0.6~MOhm. We present experimental labor...

  2. Frequency Behavior of a Quartz Crystal Microbalance (Qcm) in Contact with Selected Solutions

    OpenAIRE

    Z. A. Talib; Z. Baba; Kurosawa, S.; H. A.A. Sidek; A. Kassimb; W. M.M. Yunus

    2006-01-01

    A device was constructed to monitor viscosity of solutions using fundamental frequency of 9 MHz and 10 MHz quartz crystal. Piezoelectric quartz crystals with gold electrodes were mounted by O-ring in between liquid flow cell. Only one side of the crystal was exposed to the solutions which were pumped through silicon tube by a peristaltic pump. The measured frequency shift was observed in order to investigate the interfacial behavior of some selected solution in contact with one surface of Qua...

  3. Effects of anti-hypertensive drugs on esophageal body contraction

    Institute of Scientific and Technical Information of China (English)

    Koichi; Yoshida; Kenji; Furuta; Kyoichi; Adachi; Shunji; Ohara; Terumi; Morita; Takashi; Tanimura; Shuji; Nakata; Masaharu; Miki; Kenji; Koshino; Yoshikazu; Kinoshita

    2010-01-01

    AIM:To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possi-ble relationship with gastro-esophageal reflux disease.METHODS:Thirteen healthy male volunteers were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure were measured using high resolution manometry. All subjects were randomly examined on four separate occasions following administrations of nifedipine,losartan,and atenolol,as well as without any drug administ...

  4. On the Feasibility of Steering Swallowable Microsystem Capsules Using Computer-Aided Magnetic Levitation

    OpenAIRE

    Wu, Billy; Mintchev, Martin

    2008-01-01

    Swallowable capsule endoscopy is used for non-invasive diagnosis of some gastrointestinal (GI) organs. However, control over the position of the capsule is a major unresolved issue. This study presents a design for steering the capsule based on magnetic levitation. The levitation is stabilized with the aid of a computer-aided feedback control system and diamagnetism. Peristaltic and gravitational forces to be overcome were calculated. A levitation setup was built to analyze the fe...

  5. Convective Heat Transfer Analysis on Prandtl Fluid Model with Peristalsis

    Directory of Open Access Journals (Sweden)

    A. Alsaedi

    2013-01-01

    Full Text Available The effects of magnetohydrodynamic (MHD on peristaltic transport of Prandtl fluid in a symmetric channel have been studied under the assumptions of long wave length and low-Reynolds number. Channel walls are considered compliant in nature. Series solutions of axial velocity, stream function and temperature are given by using regular perturbation technique for small values of Prandtl fluid parameter. The effects of physical parameters on the velocity, streamlines and temperature are examined by plotting graphs.

  6. Flexible gastrointestinal motility pressure sensors based on aluminum thin-film strain-gauge arrays

    OpenAIRE

    Silva, Luís Rebelo; Sousa, Paulo J.; L.M. Gonçalves; Minas, Graça

    2015-01-01

    This paper reports on an innovative approach to measuring intraluminal pressure in the upper gastrointestinal (GI) tract, especially monitoring GI motility and peristaltic movements. The proposed approach relies on thin-film aluminum strain gauges deposited on top of a Kapton membrane, which in turn lies on top of an SU-8 diaphragm-like structure. This structure enables the Kapton membrane to bend when pressure is applied, thereby affecting the strain gauges and effectively cha...

  7. Interstitial cells of Cajal, the Maestro in health and disease

    Institute of Scientific and Technical Information of China (English)

    Randa; M; Mostafa; Yasser; M; Moustafa; Hosam; Hamdy

    2010-01-01

    Interstitial cells of Cajal (ICC) are important players in the symphony of gut motility. They have a very signif icant physiological role orchestrating the normal peristaltic activity of the digestive system. They are the pacemaker cells in gastrointestinal (GI) muscles. Absence, reduction in number or altered integrity of the ICC network may have a dramatic effect on GI system motility. More understanding of ICC physiology will foster advances in physiology of gut motility which will help in a future break...

  8. New deep glass etching technology

    OpenAIRE

    Bu, M.; Melvin, T; Ensell, G; J. S. Wilkinson; Evans, A.G.R.

    2003-01-01

    A new masking technology useful for wet etching of glass, to a depth of more than 300 ?m, is reported; multilayers of metal in combination with thick SPRT220 photoresist, are used. This new method was successfully developed for fabricating a 200 ?m thick diaphragm for a micro peristaltic pump. Various mask materials, which can be patterned by standard photolithography and metal etching processes, were investigated. The main advantage of this newly developed method was the application of hydro...

  9. Collection of islets of Langerhans using an equilibrium method

    OpenAIRE

    Koh, Duk-Su; Moody, Mark; Jo, Junghyo

    2013-01-01

    Here we present a convenient method for easy hand-selection of enzymatically isolated small tissues such as islets. This method using a micropipette tip connected to a peristaltic pump collects islets in the tip continuously. After entering a conical micropipette tip, islets are quickly dragged up by solution flow, and this movement subsequently decreases as the flow rate decreases. The islets are trapped at a specific height when downward gravitation balances upward buoyancy and drag provide...

  10. Evaluation of blood compatibility of plasma deposited heparin-like films and SF6 plasma treated surfaces

    OpenAIRE

    Ivanira Antunes Perrenoud; Elidiane Cipriano Rangel; Rogério Pinto Mota; Steven Frederick Durrant; Nilson Cristino da Cruz

    2010-01-01

    In devices used in open-heart surgery and dialysis, blood must be continuously processed using extracorporeal circuits composed of peristaltic pumps and active components such as specific filters and oxygenators. Several procedures have been employed to avoid blood coagulation induced by contact with the artificial surfaces of such devices. Often heparin, a bioactive protein able to prevent clot formation, is employed. In this work, we have used heparin-containing gas plasmas to evaluate the ...

  11. Flow of MHD Carreau Fluid in a Curved Channel

    Directory of Open Access Journals (Sweden)

    Saima Noreen

    2013-01-01

    Full Text Available Analysis has been made for the curvature effects on the MHD peristaltic flow of an incompressible Carreau fluid in a channel. The flow problem is first reduced in the wave frame of reference and then solved after employing the long wavelength and low Reynolds number approximations. Expressions of stream function, pressure gradient, magnetic force function, induced magnetic field and current density are derived and then examined for various parameters of interest.

  12. Magnetohydrodynamic flow of a Carreau fluid in an channel with different wave forms

    Energy Technology Data Exchange (ETDEWEB)

    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; Mesloub, Said [King Saud Univ., Riyadh (Saudi Arabia). Dept. of Mathematics; Ali, Nasir [International Islamic Univ., Islamabad (Pakistan). Faculty of Basic and Applied Sciences

    2011-03-15

    In this investigation, we discuss the peristaltic motion based on the constitutive equations of a Carreau fluid in a channel. The fluid is electrically conducting in the presence of a uniform applied magnetic field. Four different wave forms are chosen. The fluid behaviour is studied using long wavelength approximation. Detailed analysis is performed for various emerging parameters on pumping and trapping phenomena. The present results reduce favourably with the currently available results of hydrodynamic case when the Hartman number is chosen zero. (orig.)

  13. Single column sequential extraction of Ra, Nd, Th, Pa and U from a natural sample

    OpenAIRE

    Jeandel, C.; Venchiarutti, C.; Bourquin, M.; Pradoux, C; Lacan, F.; P. van Beek; Riotte, Jean

    2011-01-01

    A new procedure allowing the sequential extraction of Ra, Nd, Th, Pa and U from the same initial natural sample (sea or river waters, particles, sediments, rocks) is proposed. Extraction recoveries were better than 90%. Procedural blanks ranged from 80 pg (for Nd) to below 1 fg, the detection limit of the MC-ICP-MS used (for Pa); all were negligible compared with the amounts of elements currently determined. Based on classical anionic resins attached to a peristaltic pump allowing precise flo...

  14. Organ culture of fetal rat small intestine for testing gluten toxicity: a reappraisal.

    OpenAIRE

    Wood, G. M.; Howdle, P. D.; Losowsky, M. S.

    1987-01-01

    Jejunal segments from fetal rats of 18 days gestation were maintained in an organ culture system for up to 72 h. During this period, villi developed within the intestinal lumen and the epithelium changed from stratified to simple columnar. Peristaltic activity was observed during in-vitro culture. Alkaline phosphatase specific activity of the bowel segments fell after 48 hours culture, compared with pre-culture values (P less than 0.05), but that of alpha-glucosidase increased. The addition o...

  15. LabVIEW-based sequential-injection analysis system for the determination of trace metals by square-wave anodic and adsorptive stripping voltammetry on mercury-film electrodes

    OpenAIRE

    Anastasios Economou; Anastasios Voulgaropoulos

    2003-01-01

    The development of a dedicated automated sequential-injection analysis apparatus for anodic stripping voltammetry (ASV) and adsorptive stripping voltammetry (AdSV) is reported. The instrument comprised a peristaltic pump, a multiposition selector valve and a home-made potentiostat and used a mercury-film electrode as the working electrodes in a thin-layer electrochemical detector. Programming of the experimental sequence was performed in LabVIEW 5.1. The sequence of operations included format...

  16. Sensitive and Real-Time Method for Evaluating Corneal Barrier Considering Tear Flow

    OpenAIRE

    Nakamura, Tadahiro; Teshima, Mugen; Kitahara, Takashi; Sasaki, Hitoshi; Uematsu, Masafumi; Kitaoka, Takashi; Nakashima, Mikiro; Nishida, Koyo; Nakamura, Junzo; Higuchi, Shun

    2010-01-01

    We developed a new electrophysiological method mimicking tear flow to evaluate the epithelial tight junction of rabbit cornea quantitatively. We investigated the effect of tear flow on the corneal damage induced by ophthalmic preservatives using this method. An Ussing chamber system with Ag/AgCl electrodes was used in the electrophysiological experiment. The excised rabbit cornea was mounted in the Ussing chamber and the precorneal solution in the chamber was perfused with a peristaltic pump ...

  17. A Continuous Flow System for the Measurement of Ambient Nitrogen Oxides [NO + NO2] Using Rhodamine B Hydrazide as a Chemosensor

    OpenAIRE

    Pandurangappa Malingappa; Venkataramanappa Yarradoddappa

    2014-01-01

    A new chemosensor has been used to monitor atmospheric nitrogen oxides [NO + NO2] at parts per billion (ppb) level. It is based on the catalytic reaction of nitrogen oxides with rhodamine B hydrazide (RBH) to produce a colored compound through the hydrolysis of the amide bond of the molecule. A simple colorimeter has been used to monitor atmospheric nitrogen dioxide at ppb level. The air samples were purged through a sampling cuvette containing RBH solution using peristaltic pump. The propose...

  18. Multi-column step-gradient chromatography system for automated ion exchange separations

    International Nuclear Information System (INIS)

    A multi-column step-gradient chromatography system has been designed to perform automated sequential separations of radionuclides by ion exchange chromatography. The system consists of a digital programmer with automatic stream selection valve, two peristaltic pumps, ten columns, and a fraction collector. The automation allows complicated separations of radionuclides to be made with minimal analyst attention and allows for increased productivity and reduced cost of analyses. Results are reported for test separations on mixtures of radionuclides by the system

  19. Analysis and Implementation of Multiple Bionic Motion Patterns for Caterpillar Robot Driven by Sinusoidal Oscillator

    OpenAIRE

    Yanhe Zhu; Xiaolu Wang; Jizhuang Fan; Sajid Iqbal; Dongyang Bie; Jie Zhao

    2014-01-01

    Articulated caterpillar robot has various locomotion patterns—which make it adaptable to different tasks. Generally, the researchers have realized undulatory (transverse wave) and simple rolling locomotion. But many motion patterns are still unexplored. In this paper, peristaltic locomotion and various additional rolling patterns are achieved by employing sinusoidal oscillator with fixed phase difference as the joint controller. The usefulness of the proposed method is verified using simulati...

  20. In Vitro Testing of a Novel Blood Pump Designed for Temporary Extracorporeal Support

    OpenAIRE

    Spurlock, DJ; Ranney, DN; Fracz, E; Mazur,; Bartlett, RH; Haft, JW

    2012-01-01

    Extracorporeal blood pumps are used as temporary ventricular assist devices or for extracorporeal membrane oxygenation. The ideal pump would be intrinsically self-regulating, carry no risk of cavitation or excessive inlet suction, be afterload insensitive, and valveless thus reducing thrombogenicity. Currently used technology, including roller, centrifugal, and pneumatic pulsatile pumps, does not meet these requirements. We studied a non-occlusive peristaltic pump (M-Pump) in two mock circula...

  1. Successful in vitro expansion and Characterization of Human Enteric Neuronal cells- A step towards Cell based therapies for Hirschsprung’s disease

    OpenAIRE

    Balamurugan M.; Preethy SP; Tholcopiyan L; Thamaraikannan; Srinivasan V; Murugan P; Manjunath S; Srinivasan T; Krishnamohan J; Abraham S

    2010-01-01

    BACKGROUND: The Enteric Nervous system (ENS) is a part of the Peripheral nervous system (PNS) that controls the peristaltic activity of the gut wall which is essential for propulsion of food in the digestive tract. It is composed of a large number of neurons and glial cells, distributed throughout the length of the gut. These ganglion cells develop from the neural crest in the embryo. Failure of complete colonization of the gut by these enteric neural crest cells during early development of l...

  2. STUDY ON 52 PATIENTS WITH ACUTE SEVERE ORGANOPHOSPHORUS PESTICIDE POISONING%急性重度有机磷中毒52例临床研究

    Institute of Scientific and Technical Information of China (English)

    孟瑞; 卢敏

    2011-01-01

    Objective To evaluate the clinical application of hemoperfusion combined with hemodialysis and continuous micropump infusion of atropine in the treatment of acute severe organophosphorus pesticide poisoning( ASOPP ). Methods A total of 104 patients with ASOPP were retrospectively analysed, all patients were treated with gastric lavage and so on, the treated group adopted hemoperfusion combined with hemodialysis and continuous micropump infusion of atropine in addition to basic therapy. The clinical data was compared. Results The treated group was superior to the control group in time from coma to consciousness, total amount of atropine and recovery time of cholinesterase etc. The recovery rate was 84.6%. Conclusion It is effective to apply hemoperfusion combined with hemodialysis and continuous micropump iffusion of atropine in rescuing the acute severe organophosphorus pesticide poisoning.%目的 评价血液灌流联合血液透析、阿托品微量泵持续泵入治疗急性重度有机磷中毒(acute severe organophosphorus pesticide poisoning,ASOPP)的临床应用价值.方法 对104例ASOPP患者进行回顾性分析,所有患者均给予洗胃等治疗,治疗组在对照组基础上加用血液灌流联合血液透析、阿托品微量泵治疗,比较2组各项临床资料.结果 治疗组昏迷至清醒时间、阿托品总量、胆碱酯酶恢复时间等明显优于对照组,治愈率为84.6%.结论 应用血液灌流联合血液透析、阿托品微量泵治疗ASOPP效果较好.

  3. Function of longitudinal vs circular muscle fibers in esophageal peristalsis, deduced with mathematical modeling

    Institute of Scientific and Technical Information of China (English)

    James G Brasseur; Mark A Nicosia; Anupam Pal; Larr S Miller

    2007-01-01

    We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest.However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be required for peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.

  4. A Microfluidic Pump/Valve Inspired by Xylem Embolism and Transpiration in Plants

    OpenAIRE

    Li Jingmin; Liu Chong; Xu Zheng; Zhang Kaiping; Ke Xue; Wang Liding

    2012-01-01

    In plants, transpiration draws the water upward from the roots to the leaves. However, this flow can be blocked by air bubbles in the xylem conduits, which is called xylem embolism. In this research, we present the design of a biomimetic microfluidic pump/valve based on water transpiration and xylem embolism. This micropump/valve is mainly composed of three parts: the first is a silicon sheet with an array of slit-like micropores to mimic the stomata in a plant leaf; the second is a piece of ...

  5. Analysis of Asymmetric Piezoelectric Composite Beam

    CERN Document Server

    Chen, J -S; Wu, K -C

    2008-01-01

    This paper deals with the vibration analysis of an asymmetric composite beam composed of glass a piezoelectric material. The Bernoulli's beam theory is adopted for mechanical deformations, and the electric potential field of the piezoelectric material is assumed such that the divergence-free requirement of the electrical displacements is satisfied. The accuracy of the analytic model is assessed by comparing the resonance frequencies obtained by the analytic model with those obtained by the finite element method. The model developed can be used as a tool for designing piezoelectric actuators such as micro-pumps.

  6. A Disposable Polymer Lab-On-A-Slide For Point-Of-Care Diagnostics Of Methicillin-Resistant Staphylococcus Aureus (Mrsa)

    DEFF Research Database (Denmark)

    Bu, Minqiang; R. Perch-Nielsen, Ivan; Skov, Julia;

    2013-01-01

    This paper reports the design, fabrication and experimental verification of a polymer microfluidic labon-a-slide for rapid detection of methicillin-resistant Staphylococcus aureus (MRSA). MRSA cells were captured in a lysis chamber using magnetic beads, followed by thermal lysis. The released DNA...... was transferred into a second chamber for polymerase chain reaction (PCR) amplification. Fluidic control in the device was accomplished by pneumatic actuation of a micropump and five microvalves integrated on the device. The mecA gene from MRSA was successfully amplified by real-time PCR within 35 min. Presence...

  7. A conductivity-based interface tracking method for microfluidic application

    Science.gov (United States)

    Salgado, Juan David; Horiuchi, Keisuke; Dutta, Prashanta

    2006-05-01

    A novel conductivity-based interface tracking method is developed for 'lab-on-a-chip' applications to measure the velocity of the liquid-gas boundary during the filling process. This interface tracking system consists of two basic components: a fluidic circuit and an electronic circuit. The fluidic circuit is composed of a microchannel network where a number of very thin electrodes are placed in the flow path to detect the location of the liquid-gas interface in order to quantify the speed of a traveling liquid front. The electronic circuit is placed on a microelectronic chip that works as a logical switch. This interface tracking method is used to evaluate the performance of planar electrokinetic micropumps formed on a hybrid poly-di-methyl-siloxane (PDMS)-glass platform. In this study, the thickness of the planar micropump is set to be 10 µm, while the externally applied electric field is ranged from 100 V mm-1 to 200 V mm-1. For a particular geometric and electrokinetic condition, repeatable flow results are obtained from the speed of the liquid-gas interface. Flow results obtained from this interface tracking method are compared to those of other existing flow measuring techniques. The maximum error of this interface tracking sensor is less than 5%, even in an ultra low flow velocity.

  8. Micro space power system using MEMS fuel cell for nano-satellites

    Science.gov (United States)

    Lee, Jongkwang; Kim, Taegyu

    2014-08-01

    A micro space power system using micro fuel cell was developed for nano-satellites. The power system was fabricated using microelectromechanical system (MEMS) fabrication technologies. Polymer electrolyte membrane (PEM) fuel cell was selected in consideration of space environment. Sodium borohydride (NaBH4) was selected as a hydrogen source while hydrogen peroxide (H2O2) was selected as an oxygen source. The power system consists of a micro fuel cell, micro-reactor, micro-pump, and fuel cartridges. The micro fuel cell was fabricated on a light-weight and corrosion-resistant glass plates. The micro-reactor was used to generate hydrogen from NaBH4 alkaline solution via a catalytic hydrolysis reaction. All components such as micro-pump, fuel cartridges, and auxiliary battery were integrated for a complete power system. The storability of NaBH4 solution was evaluated at -25 °C and the performance of the micro power system was measured at various operating conditions. The power output of micro power system reasonably followed up the given electric load conditions.

  9. A Digitally Controllable Polymer-Based Microfluidic Mixing Module Array

    Directory of Open Access Journals (Sweden)

    Raymond H. W. Lam

    2012-03-01

    Full Text Available This paper presents an integrated digitally controllable microfluidic system for continuous solution supply with a real-time concentration control. This system contains multiple independently operating mixing modules, each integrated with two vortex micropumps, two Tesla valves and a micromixer. The interior surface of the system is made of biocompatible materials using a polymer micro-fabrication process and thus its operation can be applied to chemicals and bio-reagents. In each module, pumping of fluid is achieved by the vortex micropump working with the rotation of a micro-impeller. The downstream fluid mixing is based on mechanical vibrations driven by a lead zirconate titanate ceramic diaphragm actuator located below the mixing chamber. We have conducted experiments to prove that the addition of the micro-pillar structures to the mixing chamber further improves the mixing performance. We also developed a computer-controlled automated driver system to control the real-time fluid mixing and concentration regulation with the mixing module array. This research demonstrates the integration of digitally controllable polymer-based microfluidic modules as a fully functional system, which has great potential in the automation of many bio-fluid handling processes in bio-related applications.

  10. Microactuator using fluid materialization of high output micro machines

    International Nuclear Information System (INIS)

    Many kinds of microactuators using functional fluids such as ERF (Electro-Rheological Fluids), MRF (Magneto-Rheological Fluids) and ECF (Electro-Conjugate Fluids) have been studied. Some examples of them are stated. A valve-integrated microactuator using particle dispersion ER fluids, homogeneous ER fluids, and EC fluids and micropump, which were investigated by authors, are stated. The flow characteristics of ERF, micro ER valve with 3 ports, the valve-integrated microactuator using ER fluids, the control system of micro position using homogeneous ERF, structure of 3kinds of EFC motors and micro-pumps are illustrated and explained. The particle dispersion ERF, of which coefficient of viscosity is 0.22 Pa ·s at 26degC, consists of the high specific gravity silicon oil with 30wt% composite materials having diameter of 8μm. The micro ER valve showed 0.25MPa pressure change under the conditions of 0.4 MPa pressure and 5.0 kV/mm sum of electric field strength of electrode between the upper and the lower stream. (S.Y.)

  11. Fabrication of plastic microfluidic components

    Science.gov (United States)

    Martin, Peter M.; Matson, Dean W.; Bennett, Wendy D.; Hammerstrom, D. J.

    1998-09-01

    Plastic components have many advantages, including ease of fabrication, low cost, chemical inertness, lightweight, and disposability. We report on the fabrication of three plastics-based microfluidic components: a motherboard, a dialysis unit, and a metal sensor. Microchannels, headers, and interconnects were produced in thin sheets (>=50 microns) of polyimide, PMMA, polyethylene, and polycarbonate using a direct-write excimer laser micromachining system. Machined sheets were laminated by thermal and adhesive bonding to form leak-tight microfluidic components. The microfluidic motherboard borrowed the `functionality on a chip' concept from the electronics industry and was the heart of a complex microfluidic analytical device. The motherboard platform was designed to be tightly integrated and self-contained (i.e., liquid flows are all confined within machined microchannels), reducing the need for tubing with fluid distribution and connectivity. This concept greatly facilitated system integration and miniaturization. As fabricated, the motherboard consisted of three fluid reservoirs connected to micropumps by microchannels. The fluids could either be pumped independently or mixed in microchannels prior to being directed to exterior analytical components via outlet ports. The microdialysis device was intended to separate electrolytic solutes from low volume samples prior to mass spectrometric analysis. The device consisted of a dialysis membrane laminated between opposed serpentine microchannels containing the sample fluid and a buffer solution. The laminated metal sensor consisted of fluid reservoirs, micro-flow channels, micropumps, mixing channels, reaction channels, and detector circuitry.

  12. Vacuum-driven power-free microfluidics utilizing the gas solubility or permeability of polydimethylsiloxane (PDMS).

    Science.gov (United States)

    Xu, Linfeng; Lee, Hun; Jetta, Deekshitha; Oh, Kwang W

    2015-10-21

    Suitable pumping methods for flow control remain a major technical hurdle in the path of biomedical microfluidic systems for point-of-care (POC) diagnostics. A vacuum-driven power-free micropumping method provides a promising solution to such a challenge. In this review, we focus on vacuum-driven power-free microfluidics based on the gas solubility or permeability of polydimethylsiloxane (PDMS); degassed PDMS can restore air inside itself due to its high gas solubility or gas permeable nature. PDMS allows the transfer of air into a vacuum through it due to its high gas permeability. Therefore, it is possible to store or transfer air into or through the gas soluble or permeable PDMS in order to withdraw liquids into the embedded dead-end microfluidic channels. This article provides a comprehensive look at the physics of the gas solubility and permeability of PDMS, a systematic review of different types of vacuum-driven power-free microfluidics, and guidelines for designing solubility-based or permeability-based PDMS devices, alongside existing applications. Advanced topics and the outlook in using micropumping that utilizes the gas solubility or permeability of PDMS will be also discussed. We strongly recommend that microfluidics and lab-on-chip (LOC) communities harness vacuum energy to develop smart vacuum-driven microfluidic systems.

  13. Automated microfluidic DNA/RNA extraction with both disposable and reusable components

    International Nuclear Information System (INIS)

    An automated microfluidic nucleic extraction system was fabricated with a multilayer polydimethylsiloxane (PDMS) structure that consists of sample wells, microvalves, a micropump and a disposable microfluidic silica cartridge. Both the microvalves and micropump structures were fabricated in a single layer and are operated pneumatically using a 100 µm PDMS membrane. To fabricate the disposable microfluidic silica cartridge, two-cavity structures were made in a PDMS replica to fit the stacked silica membranes. A handheld controller for the microvalves and pumps was developed to enable system automation. With purified ribonucleic acid (RNA), whole blood and E. coli samples, the automated microfluidic nucleic acid extraction system was validated with a guanidine-based solid phase extraction procedure. An extraction efficiency of ∼90% for deoxyribonucleic acid (DNA) and ∼54% for RNA was obtained in 12 min from whole blood and E. coli samples, respectively. In addition, the same quantity and quality of extracted DNA was confirmed by polymerase chain reaction (PCR) amplification. The PCR also presented the appropriate amplification and melting profiles. Automated, programmable fluid control and physical separation of the reusable components and the disposable components significantly decrease the assay time and manufacturing cost and increase the flexibility and compatibility of the system with downstream components

  14. Use of Buckling Instabilities in Micro Pumps, Valves, and Mixers

    Science.gov (United States)

    Tavakol, Behrouz; Chawan, Aschvin; Holmes, Douglas

    2014-03-01

    We use the buckling of thin, flexible plates for pumping fluids, controlling the flow rate, and mixing different media within a microfluidic channel. A dielectric elastomeric film with a confined geometry buckles out of the plane when exposed to an electric field. Solid or grease electrodes have traditionally been used as conductive materials to aid in voltage application to both sides of the film. In this work, we use an electrolytic fluid solution as the electrode to enable buckling at relatively low voltages, and to enhance the rate of deformation. We show that this mechanism can be implemented as a microvalve that controls flow rate, or as a micropump that operates over a range of frequencies. A similar mechanism can be used to aid diffusion between two adjacent laminar streams and improve mixing. These low-cost micropumps, microvalves, and micromixers rely on the reversible buckling of thin plates, are easily embeddable in a microfluidic chip, and can potentially be used in variety of applications to accurately control and manipulate fluid flow in a microchannel.

  15. Implementation of Synchronous Micromotor in Developing Integrated Microfluidic Systems

    Directory of Open Access Journals (Sweden)

    Ala'aldeen Al-Halhouli

    2014-07-01

    Full Text Available This paper introduces the synchronous micromotor concept and presents new investigations on its application as an integrated driving mechanism in microfluidic systems. A spiral channel viscous micropump and a microstirrer are considered and tested as examples to verify the concept. The fabrication technology of such integrated systems is based on UV depth lithography, electroplating and soft lithography. The synchronous micromotor consists of a stator including double layer coils, and a rotor disk containing alternate permanent magnets. The coils are distributed evenly around the stator and arranged in three phases. The phases are excited by sinusoidal currents with a corresponding phase shift resulting in a rotating magnetic field. Regarding the spiral channel viscous micropump, a spiral disk was fixed onto the rotor disk and run at different rotational speeds. Tests showed very promising results, with a flow rate up to 1023 µL·min−1 at a motor rotational speed of 4500 rpm. Furthermore, for the application of a microstirred-tank bioreactor, the rotor disk design was modified to work as a stirrer. The performance of the developed microbioreactor was tested over a time period of approximately 10 h under constant stirring. Tests demonstrated the successful cultivation of S. cerevisiae through the integration of the microstirrer in a microbioreactor system. These systems prove that synchronous micromotors are well suited to serve as integrated driving mechanisms of active microfluidic components.

  16. Uterine contractions evaluated on cine MR imaging in patients with uterine leiomyomas

    International Nuclear Information System (INIS)

    Purpose: Submucosal leiomyoma is one of the most recognized causes of infertility and habitual abortion. The purpose of this study is to evaluate uterine peristalsis, a cycle-related inherent contractility of uterus probably responsible for sperm transport and conservation of pregnancy, in patients with uterine leiomyomas using cine magnetic resonance (MR) imaging. Materials and methods: Study population consisted of 26 female patients (age range: 19-51 years, mean: 41 years), in which 16 patients had submucosal leiomyomas and 10 patients had intramural or subserosal leiomyomas. We prospectively performed MR imaging of the midsagittal plane of uterus using 1.5 T magnet (Symphony, Siemens Medical Systems) with a body array coil, and obtained 60 half-Fourier acquisition single shot turbo spin echo (HASTE) images (Echo time=80 ms, FOV=300 mm, slice thickness 5 mm, matrix 256x256) within 2 min, and displayed them on cine mode at 12x faster than real speed. Evaluated were peristaltic movements at the endometral-myometrial junction and focal myometrial movements, adjacent to leiomyomas, regarding presence, direction, frequency, and conduction. Results: The peristaltic movements were identified in 12/16 patients with submucosal lesions and 10/10 with other leiomyomas. The frequency and direction were cycle-related. Loss of peristalsis was noted adjacent to submucosal myomas in 4/12 patients, but was not in others. Focal myometrial movements were noted in 9/16 patients with submucosal myomas, but not in others. Conclusions: Uterine peristaltic movements were partly interrupted by submucosal leiomoymas, but not by myometrial or subserosal leiomyomas. Loss of peristalsis and focal myometrial movements was noted only adjacent to submucosal leiomyomas. These findings are considered to represent dysfunctional contractility, and may be related with pregnancy loss

  17. Nanofluid transport in a living soft microtube

    International Nuclear Information System (INIS)

    The mechanism of hydrodynamic transport of nanoparticles in living tissues by intrinsic lymphatic pumping remains one of the fundamental questions in the field of nanomedicine. However, despite its importance, direct visualization of the nanofluid transport mechanism has not been achieved. In this article, we report a novel in situ fluorescence bioimaging method for observing real-time microflow patterns of nanofluids confined in a contracting and expanding soft microtube. This method allows for physiological monitoring of spatiotemporally resolved microfluidic behaviour and channel undulation during the peristaltic transport of fluorescent nanoparticle suspensions by lymph vessels embedded in bulky tissues at the location of the hindlimb. The fluorescent nanofluid conferred a high optical contrast for the visualization of the lymphatic microtube, with which the concentration and viscosity of the nanofluid could be determined. The nanofluid and microtube mechanics of the hindlimb lymph vessels exhibited similar behaviours as the previously described base fluid flow of peristaltic mesenteric lymph vessels. Specifically, the microtube contraction and expansion induced increased forward flows, and a reverse flow developed at the maximum contraction, all of which corresponded to Poiseuille flow and implied that higher tube wall shear stress was related to increased axial flow velocity. On the other hand, our study identified a highly heterogeneous flow pattern that could appear during the microtube expansion phase, whose axial velocity profile remarkably deviated from the Hagen–Poiseuille equation. In addition, the peristaltic pumping power was estimated to be on the nanowatt order of magnitude. Finally, we discuss the possible applications of this nanofluidic model system in the context of nanobiotechnology. (paper)

  18. Interpreting manometric signals for propulsion in the gut

    Science.gov (United States)

    Sinnott, M. D.; Cleary, P. W.; Dinning, P. G.; Arkwright, J. W.; Costa, M.

    2015-09-01

    Propulsion of intestinal contents involves coordinated contractions and relaxations of the muscle controlled by polarised enteric neural reflex pathways. Due to the inaccessibility of the small and large bowel, obtaining detailed manometric measurements in the gut or visualizing the movement of digesta is difficult in vivo. Computational modelling that incorporates the complex interactions between gut content and wall contractility has the potential to explain the mechanisms behind propulsive motor patterns and aid the interpretation of manometric measurements. We present here a biomechanical computational model of coupled wall flexure and flow dynamics in a virtual segment of intestine. The model uses the smoothed particle hydrodynamics method which permits coupling of the fluid/solid motion and wall deformation in a natural way. Peristaltic waves of contraction and relaxation, similar to those observed in physiological experiments, were applied to the gut wall of the model. A catheter containing manometric sensors was also incorporated into the model to derive representative pressure readings. The sensitivity of the model to input parameters including wall stiffness, viscosity of content and degree of muscular contraction is also presented. The results show that there is a rapid rise in pressure of fluid content trapped between the catheter and the contracting wall. The peristaltic wave travels along the length of the virtual segment of intestine passing over each sensor. The bolus, formed by the peristaltic contraction, grows in size and longitudinal extent until the bolus size reaches steady state. The wall force and the peak fluid pressure both scale proportionally with the change in muscle length, indicating that manometric data provide a reliable means for measuring the strength of contractions. Changes in stiffness of the wall and viscosity of contents result in predictable changes in the parameters of peristalsis. The model can be thus applied to manometry

  19. Nanofluid transport in a living soft microtube

    Science.gov (United States)

    Sung, Baeckkyoung; Kim, Se Hoon; Lee, Sungwoo; Lim, Jaekwan; Lee, Jin-Kyu; Soh, Kwang-Sup

    2015-09-01

    The mechanism of hydrodynamic transport of nanoparticles in living tissues by intrinsic lymphatic pumping remains one of the fundamental questions in the field of nanomedicine. However, despite its importance, direct visualization of the nanofluid transport mechanism has not been achieved. In this article, we report a novel in situ fluorescence bioimaging method for observing real-time microflow patterns of nanofluids confined in a contracting and expanding soft microtube. This method allows for physiological monitoring of spatiotemporally resolved microfluidic behaviour and channel undulation during the peristaltic transport of fluorescent nanoparticle suspensions by lymph vessels embedded in bulky tissues at the location of the hindlimb. The fluorescent nanofluid conferred a high optical contrast for the visualization of the lymphatic microtube, with which the concentration and viscosity of the nanofluid could be determined. The nanofluid and microtube mechanics of the hindlimb lymph vessels exhibited similar behaviours as the previously described base fluid flow of peristaltic mesenteric lymph vessels. Specifically, the microtube contraction and expansion induced increased forward flows, and a reverse flow developed at the maximum contraction, all of which corresponded to Poiseuille flow and implied that higher tube wall shear stress was related to increased axial flow velocity. On the other hand, our study identified a highly heterogeneous flow pattern that could appear during the microtube expansion phase, whose axial velocity profile remarkably deviated from the Hagen-Poiseuille equation. In addition, the peristaltic pumping power was estimated to be on the nanowatt order of magnitude. Finally, we discuss the possible applications of this nanofluidic model system in the context of nanobiotechnology.

  20. Uterine contractions evaluated on cine MR imaging in patients with uterine leiomyomas

    Energy Technology Data Exchange (ETDEWEB)

    Nishino, Mizuki E-mail: mizuki@mbox.kyoto-inet.or.jpnishinomizuki@hotmail.com; Togashi, Kaori; Nakai, Asako; Hayakawa, Katsumi; Kanao, Shotarou; Iwasaku, Kazuhiro; Fujii, Shingo

    2005-01-01

    Purpose: Submucosal leiomyoma is one of the most recognized causes of infertility and habitual abortion. The purpose of this study is to evaluate uterine peristalsis, a cycle-related inherent contractility of uterus probably responsible for sperm transport and conservation of pregnancy, in patients with uterine leiomyomas using cine magnetic resonance (MR) imaging. Materials and methods: Study population consisted of 26 female patients (age range: 19-51 years, mean: 41 years), in which 16 patients had submucosal leiomyomas and 10 patients had intramural or subserosal leiomyomas. We prospectively performed MR imaging of the midsagittal plane of uterus using 1.5 T magnet (Symphony, Siemens Medical Systems) with a body array coil, and obtained 60 half-Fourier acquisition single shot turbo spin echo (HASTE) images (Echo time=80 ms, FOV=300 mm, slice thickness 5 mm, matrix 256x256) within 2 min, and displayed them on cine mode at 12x faster than real speed. Evaluated were peristaltic movements at the endometral-myometrial junction and focal myometrial movements, adjacent to leiomyomas, regarding presence, direction, frequency, and conduction. Results: The peristaltic movements were identified in 12/16 patients with submucosal lesions and 10/10 with other leiomyomas. The frequency and direction were cycle-related. Loss of peristalsis was noted adjacent to submucosal myomas in 4/12 patients, but was not in others. Focal myometrial movements were noted in 9/16 patients with submucosal myomas, but not in others. Conclusions: Uterine peristaltic movements were partly interrupted by submucosal leiomoymas, but not by myometrial or subserosal leiomyomas. Loss of peristalsis and focal myometrial movements was noted only adjacent to submucosal leiomyomas. These findings are considered to represent dysfunctional contractility, and may be related with pregnancy loss.

  1. A mathematical simulation of the ureter: effects of the model parameters on ureteral pressure/flow relations.

    Science.gov (United States)

    Vahidi, Bahman; Fatouraee, Nasser; Imanparast, Ali; Moghadam, Abbas Nasiraei

    2011-03-01

    Ureteral peristaltic mechanism facilitates urine transport from the kidney to the bladder. Numerical analysis of the peristaltic flow in the ureter aims to further our understanding of the reflux phenomenon and other ureteral abnormalities. Fluid-structure interaction (FSI) plays an important role in accuracy of this approach and the arbitrary Lagrangian-Eulerian (ALE) formulation is a strong method to analyze the coupled fluid-structure interaction between the compliant wall and the surrounding fluid. This formulation, however, was not used in previous studies of peristalsis in living organisms. In the present investigation, a numerical simulation is introduced and solved through ALE formulation to perform the ureteral flow and stress analysis. The incompressible Navier-Stokes equations are used as the governing equations for the fluid, and a linear elastic model is utilized for the compliant wall. The wall stimulation is modeled by nonlinear contact analysis using a rigid contact surface since an appropriate model for simulation of ureteral peristalsis needs to contain cell-to-cell wall stimulation. In contrast to previous studies, the wall displacements are not predetermined in the presented model of this finite-length compliant tube, neither the peristalsis needs to be periodic. Moreover, the temporal changes of ureteral wall intraluminal shear stress during peristalsis are included in our study. Iterative computing of two-way coupling is used to solve the governing equations. Two phases of nonperistaltic and peristaltic transport of urine in the ureter are discussed. Results are obtained following an analysis of the effects of the ureteral wall compliance, the pressure difference between the ureteral inlet and outlet, the maximum height of the contraction wave, the contraction wave velocity, and the number of contraction waves on the ureteral outlet flow. The results indicate that the proximal part of the ureter is prone to a higher shear stress during

  2. Modelling and simulation of diffusive processes methods and applications

    CERN Document Server

    Basu, SK

    2014-01-01

    This book addresses the key issues in the modeling and simulation of diffusive processes from a wide spectrum of different applications across a broad range of disciplines. Features: discusses diffusion and molecular transport in living cells and suspended sediment in open channels; examines the modeling of peristaltic transport of nanofluids, and isotachophoretic separation of ionic samples in microfluidics; reviews thermal characterization of non-homogeneous media and scale-dependent porous dispersion resulting from velocity fluctuations; describes the modeling of nitrogen fate and transport

  3. Bioengineering fluid mechanics

    CERN Document Server

    Hung, Tin-kan

    2013-01-01

    This book highlights the basic concepts and equations for bioengineering flow processes. Physical concepts and meanings are emphasized while rigorous derivations are simplified, making it easier for self learning on some biological and medical flow processes. The well known Bernoulli equation in hydraulics is extended for pulsating flows, peristaltic flows and cardiac pumping. The dimensional analysis, model law and dimensionless equations can be related to computational models and experimental observations. The velocity vector imaging stored in echocardiograms can be used to analyze the pumping characteristics of the ventricular contraction. New topics included oxygen transport in membrane oxygenator and micro mixing of blood flow in capillary channels.

  4. Homogeneous-heterogeneous reaction effects in peristalsis through curved geometry

    Science.gov (United States)

    Hayat, Tasawar; Tanveer, Anum; Alsaadi, Fuad; Alotaibi, Naif D.

    2015-06-01

    This paper looks at the influence of homogeneous-heterogeneous reactions on the peristaltic transport of non-Newtonian fluid in a curved channel with wall properties. Constitutive relations for thermodynamic third grade material are utilized in the problem development. An electrically conducting fluid in the presence of radial applied magnetic field is considered. The governing flow equations are developed in the presence of viscous heating. Mathematical computations are simplified employing long wavelength and low Reynolds number considerations. The solutions for velocity, temperature, concentration and heat transfer coefficient are obtained and examined. The features of sundry parameters are analyzed by plotting graphs.

  5. Homogeneous-heterogeneous reaction effects in peristalsis through curved geometry

    Directory of Open Access Journals (Sweden)

    Tasawar Hayat

    2015-06-01

    Full Text Available This paper looks at the influence of homogeneous-heterogeneous reactions on the peristaltic transport of non-Newtonian fluid in a curved channel with wall properties. Constitutive relations for thermodynamic third grade material are utilized in the problem development. An electrically conducting fluid in the presence of radial applied magnetic field is considered. The governing flow equations are developed in the presence of viscous heating. Mathematical computations are simplified employing long wavelength and low Reynolds number considerations. The solutions for velocity, temperature, concentration and heat transfer coefficient are obtained and examined. The features of sundry parameters are analyzed by plotting graphs.

  6. Homogeneous-heterogeneous reaction effects in peristalsis through curved geometry

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Tasawar [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Department of Electrical and Computer Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Tanveer, Anum, E-mail: qau14@yahoo.com; Alsaadi, Fuad [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Alotaibi, Naif D. [Department of Electrical and Computer Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-06-15

    This paper looks at the influence of homogeneous-heterogeneous reactions on the peristaltic transport of non-Newtonian fluid in a curved channel with wall properties. Constitutive relations for thermodynamic third grade material are utilized in the problem development. An electrically conducting fluid in the presence of radial applied magnetic field is considered. The governing flow equations are developed in the presence of viscous heating. Mathematical computations are simplified employing long wavelength and low Reynolds number considerations. The solutions for velocity, temperature, concentration and heat transfer coefficient are obtained and examined. The features of sundry parameters are analyzed by plotting graphs.

  7. Resonance Frequency of Optical Microbubble Resonators: Direct Measurements and Mitigation of Fluctuations

    Science.gov (United States)

    Cosci, Alessandro; Berneschi, Simone; Giannetti, Ambra; Farnesi, Daniele; Cosi, Franco; Baldini, Francesco; Nunzi Conti, Gualtiero; Soria, Silvia; Barucci, Andrea; Righini, Giancarlo; Pelli, Stefano

    2016-01-01

    This work shows the improvements in the sensing capabilities and precision of an Optical Microbubble Resonator due to the introduction of an encaging poly(methyl methacrylate) (PMMA) box. A frequency fluctuation parameter σ was defined as a score of resonance stability and was evaluated in the presence and absence of the encaging system and in the case of air- or water-filling of the cavity. Furthermore, the noise interference introduced by the peristaltic and the syringe pumping system was studied. The measurements showed a reduction of σ in the presence of the encaging PMMA box and when the syringe pump was used as flowing system. PMID:27589761

  8. The Application of Flow Injection Technology to Automating Cold Vapor Mercury Analyses in Aquatic Ecosystems

    Directory of Open Access Journals (Sweden)

    TEODOROF, L.

    2009-02-01

    Full Text Available Based on flow injection techniques, FIMS is fully automated, fast, and cost-effective. The FIMS uses a high-performance single-beam optical system with a low pressure mercury lamp and solar-blind detector for maximum performance. The FIMS-400 has two stepper motor-driven peristaltic pumps for greater flexibility when used with optional accessories. FIMS is fully controlled from a personal computer using WinLab32 for AA software, a true Microsoft Windows-based program with an unparalleled offering of standard features, including a full range of analytical checks and quality control functions.

  9. The MainSTREAM Component Platform: A Holistic Approach to Microfluidic System Design

    DEFF Research Database (Denmark)

    Sabourin, David; Skafte-Pedersen, Peder; Søe, Martin Jensen;

    2013-01-01

    A microfluidic component library for building systems driving parallel or serial microfluidic-based assays is presented. The components are a miniaturized eight-channel peristaltic pump, an eight-channel valve, sample-to-waste liquid management, and interconnections. The library of components...... of reaction chips; (2) highly parallel pumping and routing/valving capability; (3) methods to interface pumps and chip-to-liquid management systems; (4) means to construct a portable system; (5) reconfigurability/flexibility in system design; (6) means to interface to microscopes; and (7) compatibility...

  10. Computed tomography studies of human brain movements

    International Nuclear Information System (INIS)

    Rhythmic brain movements have been revealed by sets of sequential computed tomography scans of human brains (seen retrospectively to be normal). These scans have shown that both (unenhanced) brain parenchymal density and the shapes of the elements of the supratentorial ventricular/cisternal system are subject to wave motions having similar periods - ranging from 26 s through 56 s, 77-96 s, 109 s and 224 s to 224 X 2 s (or even longer), with good correlation between peak values. These motions, as well as phase variations between the waves, suggest a peristaltic movement of cerebrospinal fluid through the ventricular/cisternal system with progressive axial damping

  11. Slow rhythmic ventricular oscillations and parenchymal density variations shown by sequential CT scanning

    International Nuclear Information System (INIS)

    Rhythmic brain movements have been revealed by sets of sequential computerised tomography scans of human brains (seen retrospectively to be normal). These scans have shown that both (unenhanced) brain parenchymal density and the shapes of the elements of the supratentorial ventricular/cisternal system are subject to wave motions having similar periods-ranging from 26 s through 56 s, 77-96 s, 109 s, and 224 s to 224 x 2 s (or even longer), with good correlation between peak values. These motions, as well as phase variations between the waves suggest a peristaltic movement of CSF through the ventricular/cisternal system with progressive axial damping

  12. Polychlorinated biphenyls (PCB) analysis report for solid sample from 219S tank 101

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, L.A.

    1998-02-04

    One waste sample that was obtained with solids from tank 101 of 219S via a peristaltic pump equipped with a stainless steel tube and Norprene tubing (Phthalate free) was obtained in a glass jar with teflon lid was analyzed (with duplicate, matrix spike, and matrix spike duplicate) for PCBs as Aroclor mixtures by the Inorganic/Organic Chemistry Group. A soxhlet extraction procedure was used for extraction of the Aroclors from the sample. Analysis was performed using dual column confirmation gas chromatography/electron capture detection (GC/ECD). Results are presented.

  13. Mixed convection flow of nanofluid in presence of an inclined magnetic field.

    Directory of Open Access Journals (Sweden)

    Saima Noreen

    Full Text Available This research is concerned with the mixed convection peristaltic flow of nanofluid in an inclined asymmetric channel. The fluid is conducting in the presence of inclined magnetic field. The governing equations are modelled. Mathematical formulation is completed through long wavelength and low Reynolds number approach. Numerical solution to the nonlinear analysis is made by shooting technique. Attention is mainly focused to the effects of Brownian motion and thermophoretic diffusion of nanoparticle. Results for velocity, temperature, concentration, pumping and trapping are obtained and analyzed in detail.

  14. Polychlorinated biphenyls (PCB) analysis report for solid sample from 219S tank 101

    International Nuclear Information System (INIS)

    One waste sample that was obtained with solids from tank 101 of 219S via a peristaltic pump equipped with a stainless steel tube and Norprene tubing (Phthalate free) was obtained in a glass jar with teflon lid was analyzed (with duplicate, matrix spike, and matrix spike duplicate) for PCBs as Aroclor mixtures by the Inorganic/Organic Chemistry Group. A soxhlet extraction procedure was used for extraction of the Aroclors from the sample. Analysis was performed using dual column confirmation gas chromatography/electron capture detection (GC/ECD). Results are presented

  15. Backflushing Filters for Field Processing of Water Samples Prior to Trace-Element Analyses

    Science.gov (United States)

    Kennedy, V.C.; Jenne, E.A.; Burchard, J.M.

    1976-01-01

    A portable unit is described for filtering water samples at field sites in such a manner that the filtrate is suitable for analysis not only of major constituents but also of trace elments at the mocrogram-per-liter level. A battery-operated peristaltic pump forces the water sample through medical-grade silicone tubing into and through an all-plastic in-line filter which can be backflushed when sediment clogs the filter membrane. Initial filtration rate exceeds 500 milliliter/minute and, because of the backflushing feature, a total time for filtering high-sediment-bearing waster samples is greatly reduced. (Woodard-USGS)

  16. Silicon micromachined pumps employing piezoelectric membrane actuation for microfluidic systems

    Science.gov (United States)

    Koch, Michael

    Microsystems technology is a rapidly expanding area that comprises electronics, mechanics and optics. In this field, physical/chemical sensing, fluid handling and optical communication are emerging as potential markets. Microfluidic systems like an implantable insulin pump, a drug delivery system and a total chemical analysis system are currently being developed by academia and industry around the world. This project contributes to the area of microfluidics in that a novel thick-film-on-silicon membrane actuator has been developed to allow inexpensive mass production of micropumps. To date piezoelectric plates have been surface mounted onto a silicon membrane. This single chip fabrication method can now be replaced by screen printing thick piezoelectric layers onto 4 inch silicon substrates. Two different pump types have been developed. These are membrane pumps with either cantilever valves or diffuser/nozzle valves. Pump rates between 100 and 200 μl min-1 and backpressures up to 4 kPa have been achieved with these pumps. Along with the technology of micropumps, simulators have been developed. A novel coupled FEM-CFD solver was realised by a computer controlled coupling of two commercially available packages (ANSYS and CFX-Flow3D). The results of this simulator were in good agreement with measurements on micromachined cantilever valves. CFX- Flow3D was also used to successfully model the behaviour of the diffuser/nozzle valve. Finally, the pump has been simulated using a continuity equation. A behavioural dynamic extension of the cantilever valve was necessary to achieve better prediction of the pump rates for higher frequencies. As well, a common process has been developed for microfluidic devices like micromixers, particle counters and sorters as well as flow sensors. The micromixer has been tested already and achieves mixing for input pressures between 2 and 7 kPa. This agrees with simulations of the diffusive mixing with CFX-Flow3D. Together with the micropump

  17. Rapid chemiluminometric determination of gabapentin in pharmaceutical formulations exploiting pulsed-flow analysis.

    Science.gov (United States)

    Manera, Matías; Miró, Manuel; Ribeiro, Marta F T; Estela, José Manuel; Cerdà, Víctor; Santos, João L M; Lima, José L F C

    2009-01-01

    In this study, a straightforward and automated pulsed flow-based procedure was developed for the chemiluminometric determination of gabapentin [1-(aminomethyl)cyclo-hexaneacetic acid], a new generation antiepileptic drug, in different formulated dosage forms. The software-controlled time-based injection method capitalizes on the decrease of the background chemiluminescence (CL) readout of the luminol-hypochlorite reaction in the presence of gabapentin. In short, gabapentin works as a hypochlorite scavenger. The analytical procedure was implemented in a multi-pumping flow network furnished with a suite of microdispensing solenoid-actuated pumps. The diaphragm-type micropumps might be configured to operate as fluid propellers, commutation units and metering injectors. A dynamic linear working range for gabapentin concentrations in the range 60-350 micromol/L was obtained, with an estimated detection limit of 40 micromol/L. The flow analyser handles about 41 injections/h and yields precise results (RSD pharmaceutical companies. PMID:18780326

  18. Plasmonic liquid marbles: a miniature substrate-less SERS platform for quantitative and multiplex ultratrace molecular detection.

    Science.gov (United States)

    Lee, Hiang Kwee; Lee, Yih Hong; Phang, In Yee; Wei, Jiaqi; Miao, Yue-E; Liu, Tianxi; Ling, Xing Yi

    2014-05-12

    Inspired by aphids, liquid marbles have been studied extensively and have found application as isolated microreactors, as micropumps, and in sensing. However, current liquid-marble-based sensing methodologies are limited to qualitative colorimetry-based detection. Herein we describe the fabrication of a plasmonic liquid marble as a substrate-less analytical platform which, when coupled with ultrasensitive SERS, enables simultaneous multiplex quantification and the identification of ultratrace analytes across separate phases. Our plasmonic liquid marble demonstrates excellent mechanical stability and is suitable for the quantitative examination of ultratrace analytes, with detection limits as low as 0.3 fmol, which corresponds to an analytical enhancement factor of 5×10(8). The results of our simultaneous detection scheme based on plasmonic liquid marbles and an aqueous-solid-organic interface quantitatively tally with those found for the individual detection of methylene blue and coumarin.

  19. Rarefaction effects in microchannel gas flow driven by rhythmic wall contractions

    Science.gov (United States)

    Chatterjee, Krishnashis; Staples, Anne; Department of Biomedical Engineering; Mechanics, Virginia Tech Collaboration

    2015-11-01

    Current state of the art microfluidic devices employ precise and timely operation of a complex arrangement of micropumps and valves for fluid transport. A much more novel flow transport mechanism is found in entomological respiratory systems, which involve rhythmic wall contractions for driving the fluid flow. The practical viability of using this technique in future microfluidic devices has been studied earlier. The present study investigates the incorporation of rarefaction effects in the above model of microscale gas flow by including slip boundary conditions. The Navier Stokes equations for gas flow in rectangular microchannel are solved analytically with microscale and lubrication theory assumptions. First order slip boundary conditions are incorporated to account for the rarefaction effects. The dependence of fluid velocities and pressure gradient on the slip boundary conditions is studied. Time averaged unidirectional fluid flow rates are plotted for different phase lags between the contractions, with and without slip in order to obtain an optimum range under different conditions.

  20. Photothermal generation of microbubbles on plasmonic nanostructures inside microfluidic channels

    Science.gov (United States)

    Li, Jingting; Li, Ming; Santos, Greggy M.; Zhao, Fusheng; Shih, Wei-Chuan

    2016-03-01

    Microbubbles have been utilized as micro-pumps, micro-mixers, micro-valves, micro-robots and surface cleaners. Various generation techniques can be found in the literature, including resistive heating, hydrodynamic methods, illuminating patterned metal films and noble metal nanoparticles of Au or Ag. We present photothermal microbubble generation by irradiating nanoporous gold disk covered microfluidic channels. The size of the microbubble can be controlled by adjusting the laser power. The dynamics of both bubble growth and shrinkage are studied. The advantages of this technique are flexible bubble generation locations, long bubble lifetimes, no need for light-adsorbing dyes, high controllability over bubble size, low power consumption, etc. This technique has the potential to provide new flow control functions in microfluidic devices.

  1. Performances analysis of a piezo-pump

    Directory of Open Access Journals (Sweden)

    Belkhiat S.

    2012-06-01

    Full Text Available Piezo-pumps, in the last decade, have received extensive attention because of their potential applications in biomedical devices, biological and chemical analysis, micro-electronics cooling and space exploration. In this paper an analytical model is developed to analysis the parameters effect on the pump flow. The micro-pump driven by piezostack (PZT alloy multilayer as actuator is studied as function size and working middle. This one is compared with SCMCP pump actuated by PZT alloy as piezomembrane. The flow change as a function frequency, the chamber diameter and control voltage are analyzed. The simulation results obtained with two different liquids (water and blood as working middle are discussed and compared with experimental results. The results are satisfactory.

  2. Pumping by flapping in a viscoelastic fluid

    CERN Document Server

    Pak, On Shun

    2010-01-01

    In a world without inertia, Purcell's scallop theorem states that in a Newtonian fluid a time-reversible motion cannot produce any net force or net flow. Here we consider the extent to which the nonlinear rheological behavior of viscoelastic fluids can be exploited to break the constraints of the scallop theorem in the context of fluid pumping. By building on previous work focusing on force generation, we consider a simple, biologically-inspired geometrical example of a flapper in a polymeric (Oldroyd-B) fluid, and calculate asymptotically the time-average net fluid flow produced by the reciprocal flapping motion. The net flow occurs at fourth order in the flapping amplitude, and suggests the possibility of transporting polymeric fluids using reciprocal motion in simple geometries even in the absence of inertia. The induced flow field and pumping performance are characterized and optimized analytically. Our results may be useful in the design of micro-pumps handling complex fluids.

  3. Clinical microdialysis in neuro-oncology: principles and applications

    Institute of Scientific and Technical Information of China (English)

    J. Clay Goodman

    2011-01-01

    Clinical microdialysis allows a discrete volume of the brain to be sampled for neurochemical analysis of neurotransmitters, metabolites, biomarkers, and drugs. The technique can be safely used in humans intraoperatively, in the intensive care unit, and in ambulatory settings. Microdialysis probes, micropumps, and analytical equipment are commercially available and have been used extensively for neurochemical monitoring in traumatic brain injury, stroke, and subarachnoid hemorrhage. There has been very limited use of micredialysis in neuro-oncology, but this technique has groat promise in the study of the basic neurochemistry of brain tumors, alterations in neurochemistry in response to therapy, and the pharmacokinetics of chemotherapeutic agents. Microdialysis probes may also be used to deliver drugs while simultaneously permitting monitoring of neurochemical changes induced by this therapy.

  4. Microfluidic in-channel multi-electrode platform for neurotransmitter sensing

    Science.gov (United States)

    Kara, A.; Mathault, J.; Reitz, A.; Boisvert, M.; Tessier, F.; Greener, J.; Miled, A.

    2016-03-01

    In this project we present a microfluidic platform with in-channel micro-electrodes for in situ screening of bio/chemical samples through a lab-on-chip system. We used a novel method to incorporate electrochemical sensors array (16x20) connected to a PCB, which opens the way for imaging applications. A 200 μm height microfluidic channel was bonded to electrochemical sensors. The micro-channel contains 3 inlets used to introduce phosphate buffer saline (PBS), ferrocynide and neurotransmitters. The flow rate was controlled through automated micro-pumps. A multiplexer was used to scan electrodes and perform individual cyclic voltammograms by a custom potentiostat. The behavior of the system was linear in terms of variation of current versus concentration. It was used to detect the neurotransmitters serotonin, dopamine and glutamate.

  5. SmartBuild-a truly plug-n-play modular microfluidic system.

    Science.gov (United States)

    Yuen, Po Ki

    2008-08-01

    In this Technical Note, for the first time, a truly "plug-n-play" modular microfluidic system (SmartBuild Plug-n-Play Modular Microfluidic System) is presented for designing and building integrated modular microfluidic systems for biological and chemical applications. The modular microfluidic system can be built by connecting multiple microfluidic components together to form a larger integrated system. The SmartBuild System comprises of a motherboard with interconnect channels/grooves, fitting components, microchannel inserts with different configurations and microchips/modules with different functionalities. Also, heaters, micropumps and valving systems can be designed and used in the system. Examples of an integrated mixing system and reaction systems are presented here to demonstrate the versatility of the SmartBuild System. PMID:18651081

  6. Nursing care of indwelling catheter thrombolysis for acute thrombosis in the arteriovenous fistula in hemodialysis patients

    International Nuclear Information System (INIS)

    Objective: To summarize the experience of the nursing care of indwelling catheter thrombolysis for acute thrombosis in the arteriovenous fistula in eight hemodialysis patients. Methods: After breaking thrombus through indwelling catheter, both bolus injection and micro-pump continuous infusion of urokinase was employed in eight hemodialysis patients with acute thrombosis in the arteriovenous fistula. The necessary nursing measures were carried out to assist the whole therapeutic procedure. Results: All the patients could well cooperate with the procedure of indwelling catheter thrombolysis and urokinase infusion. The reopening rate of the obstructed fistula was 100%. Conclusion: Indwelling catheter thrombolysis with urokinase infusion is a simple, effective and safe treatment for acute thrombosis in the arteriovenous fistula in hemodialysis patients. In order to obtain optimal results, necessary nursing measures must be carried out. (authors)

  7. Design of Fault-Tolerant and Dynamically-Reconfigurable Microfluidic Biochips

    CERN Document Server

    Su, Fei

    2011-01-01

    Microfluidics-based biochips are soon expected to revolutionize clinical diagnosis, DNA sequencing, and other laboratory procedures involving molecular biology. Most microfluidic biochips are based on the principle of continuous fluid flow and they rely on permanently-etched microchannels, micropumps, and microvalves. We focus here on the automated design of "digital" droplet-based microfluidic biochips. In contrast to continuous-flow systems, digital microfluidics offers dynamic reconfigurability; groups of cells in a microfluidics array can be reconfigured to change their functionality during the concurrent execution of a set of bioassays. We present a simulated annealing-based technique for module placement in such biochips. The placement procedure not only addresses chip area, but it also considers fault tolerance, which allows a microfluidic module to be relocated elsewhere in the system when a single cell is detected to be faulty. Simulation results are presented for a case study involving the polymeras...

  8. Fabrication of membrane-type microvalves in rectangular microfluidic channels via seal photopolymerization.

    Science.gov (United States)

    Park, Wook; Han, Sangkwon; Kwon, Sunghoon

    2010-10-21

    Rectangular fluidic channels have rarely been used in microfluidic devices which use PDMS membrane-type microvalves, since the rectangular channel shape does not perfectly match the round shape of the membrane deformation. We present a polymer sealing method to fabricate PDMS membrane-type microvalves for rectangular microchannels. After fabricating the microfluidic device, photocurable oligomer is introduced into the fluidic channel and gas pressure is applied to the pneumatic channel to deform the membrane. The polymer seal is then locally polymerized by photolithography producing a structure matching the shape of the deformed membrane curvature. We compare the flow leakage between the membrane-type microvalve with and without a polymer seal. We also demonstrate a micropump and droplet generator using this embedded polymer membrane-type microvalve in a rectangular microfluidic channel. This polymeric seal technique enables the use of easily fabricated rectangular channel membrane microvalves with all the functionality of their curved channel counterparts with negligible flow leakage. PMID:20721367

  9. 不同输注法治疗急性胰腺炎的临床效果%Effect of different phleboclysis on acute pancreatitis patients

    Institute of Scientific and Technical Information of China (English)

    张志达; 张茂; 刘春玲; 胡江; 李明章; 侯瑞生

    2010-01-01

    目的 探讨不同输入方法治疗急性胰腺炎的综合疗效.方法 110例急性胰腺炎患者随机分为传统输液组(50例)、微量泵24 h持续泵入组(30例)和微量泵12 h持续泵入组(30例).观察统计临床治疗效果、不良反应、满意度、平均住院日等.结果 泵入组与传统组比较其临床治疗效果无差异性;药物不良反应泵入组明显低于传统组(P<0.01);满意度泵入组明显高于传统组(P<0.05).12 h泵入组与24 h泵入组比较其临床治疗效果、药物不良反应均无差异性;满意度12 h泵入组高于24 h泵入组(P<0.05).三组平均住院日传统组18 d、24 h泵入组16 d、12 h泵入组12 d.结论 12 h泵入组各项指标优于其它组,住院天数缩短,减少了病人的经济负担,扩大了社会效益.%Objective To explore the effect of different phleboclysis on acute pancreatitis patients. Methods One hundred and ten acute pancreatitis patients were randomly divided into traditional infusion group, micro-pump 24 hours continuous infusion group and 12hours continuous infusion group. The therapeutic effect, adverse reactions, the degree of satisfaction, average length of stay were observed. Results ① The therapeutic effect had no significant difference between micro-pump group and traditional group ( P > 0. 05 ) .Adverse drug reaction in micro-pump groups were significantly lower than that in traditional group ( P <0. 01 ) . The degree of satisfaction in micro-pump groups were significantly higher than that in traditional group ( P < 0. 05 ) . ②The therapeutic effect and adverse drug reactions had no significant different between the 12 hours pump group and 24 hours pump group (P > 0. 05 ) . The degree of satisfaction in 12hours pump group was higher than that of 24 hours pump group (P <0. 05) . ③The average length of stay were 18 d, 16 d, 12 d in traditional group, 24 hours pump group and 12 hours pump group respectively. Conclusions 12 hours pump group

  10. Web-Based Synthetic Optimization Design System of Micro-Components

    Institute of Scientific and Technical Information of China (English)

    GONG Xiao-yan; JIANG Ping-yu

    2005-01-01

    In order to meet the requirement of network synthesis optimization design for a micro component, a three-level information frame and functional module based on web was proposed. Firstly, the finite element method (FEM) was used to analyze the dynamic property of coupled-energy-domain of virtual prototype instances and to obtain some optimal information data. Secondly, the rough set theory (RST) and the genetic algorithm (GA) were used to work out the reduction of attributes and the acquisition of principle of optimality and to confirm key variable and restriction condition in the synthesis optimization design. Finally, the regression analysis (RA) and GA were used to establish the synthesis optimization design model and carry on the optimization design. A corresponding prototype system was also developed and the synthesis optimization design of a thermal actuated micro-pump was carried out as a demonstration in this paper.

  11. Generation of Nanoliter Droplets on Demand at Hundred-Hz Frequencies

    Directory of Open Access Journals (Sweden)

    Slawomir Jakiela

    2014-11-01

    Full Text Available We describe a precision micropump for generation of precisely metered micro-aliquots of liquid at high rates. The use of custom designed piezoelectric valves positioned externally to the microfluidic chip allows for on-demand formation of micro-droplets with online control of their individual volumes from nLs to μLs at frequencies up to 400 Hz. The system offers precision of administering volumes of 1% and of time of emission of <0.5 ms. The use of a piezoelectric actuator provides two distinct vistas for controlling the volume of the droplets—either by digital control of the “open” interval or by analogue tuning of the lumen of the valve. Fast and precise generation of droplets make this system a perfect constituent module for microfluidic high-speed combinatorial screening schemes.

  12. Mechanical Stress Downregulates MHC Class I Expression on Human Cancer Cell Membrane

    DEFF Research Database (Denmark)

    La Rocca, Rosanna; Tallerico, Rossana; Hassan, Almosawy Talib;

    2014-01-01

    treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells......In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were...... between 700–1800 cm-1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased...

  13. Autophoretic self-propulsion of homogeneous particles

    Science.gov (United States)

    Michelin, Sebastien; Lauga, Eric; de Canio, Gabriele

    2014-11-01

    Phoretic mechanisms such as diffusiophoresis exploit short-ranged interactions between solute molecules in the fluid and a rigid wall to generate local slip velocities in the presence of solute gradients along the solid boundary. This boundary flow can result in macroscopic fluid motion or phoretic migration of inert particles. These mechanisms have recently received a renewed interest to design self-propelled ``autophoretic'' systems able to generate the required solute gradients through chemical reaction at their surface. Most existing designs rely on the asymmetric chemical treatment of the particle's surface to guarantee symmetry-breaking and the generation of a net flow. We show here, however, that chemical asymmetry is not necessary for flow generation and that homogeneous particles with asymmetric geometry may lead to self-propulsion in Stokes flow. Similarly, this principle can be used to manufacture micro-pumps using channel walls with uniform chemical properties.

  14. Applications of Acoustics and Cavitation to Noninvasive Therapy and Drug Delivery

    Science.gov (United States)

    Coussios, Constantin C.; Roy, Ronald A.

    2008-01-01

    Biomedical acoustics is rapidly evolving from a diagnostic modality into a therapeutic tool, and acoustic cavitation is often the common denominator in a wide range of new therapeutic applications. High-intensity focused ultrasound (HIFU) waves generated outside the body can be used to deposit heat deep within the body. Through a quantitative analysis of heat deposition by ultrasound, it is shown that inertial cavitation can help address some of the major challenges of HIFU therapy by providing a means of enhancing and monitoring treatment noninvasively. In the context of drug delivery, both inertial and stable cavitation play roles in enhancing drug activity and uptake. In particular, shape oscillations arising during stable cavitation provide an effective micropumping mechanism for enhanced mass transport across inaccessible interfaces.

  15. Buckling instability of thin films as a means to control or enhance fluid flow within microchannel

    Science.gov (United States)

    Tavakol, Behrouz; Chawan, Aschvin; Holmes, Douglas

    2014-11-01

    Here we show that the buckling of thin, flexible plates can be used for pumping fluids, controlling the flow rate, and mixing different media within a microfluidic channel. A confined, dielectric elastomeric film buckles out of the plane when exposed to an electric field. We use an electrolytic fluid solution as the electrode to enable buckling at relatively low voltages, and to enhance the rate of deformation. When embedded in a microfluidic channel, this mechanism can be used as a microvalve that controls the flow rate, or as a micropump that alters the flow rate. A similar mechanism can be used to aid diffusion between two adjacent laminar streams and improve mixing. This novel means for dielectric actuation may improve voltage application, and the buckling microstructures may be used in variety of applications to accurately control and manipulate fluid flow in a microchannel.

  16. Pump it up

    Science.gov (United States)

    Maffli, Luc; O'Brien, Benjamin; Rosset, Samuel; Shea, Herbert

    2012-04-01

    We report on the use of zipping actuation applied to dielectric elastomer actuators to microfabricate mm-sized pumps. The zipping actuators presented here use electrostatic attraction to deform an elastomeric membrane by pulling it into contact with a rigid counter electrode. We present several actuation schemes using either conventional DEA actuation, zipping, or a combination of both in order to realize microfluidic devices. A zipping design in which the electric field is applied across the elastomer membrane was explored theoretically and experimentally. Single zipping chambers and a micropump body made of a three chambers connected by an embedded channel were wet-etched into a silicon wafer and subsequently covered by a gold-implanted silicone membrane. We measured static deflections of up to 300 μm on chambers with square openings of 1.8 and 2.6 mm side, in very good agreement with our model.

  17. Covalently immobilized gelatin gradients within three-dimensional porous scaffolds

    Institute of Scientific and Technical Information of China (English)

    WU JinDan; TAN HuaPing; LI LinHui; GAO ChangYou

    2009-01-01

    A stable gelatin gradient providing continuous increment of signaling for cell adhesion and proliferation was fabricated within 3D poly(L-lactic acid) (PLLA) scaffolds. The porous PLLA scaffold fabricated by NaCI particle leaching was vertically fixed on a glass vial. 1,6-Hexanediamine/propanol solution was continuously injected into the vial by a micropump to aminolyze the PLLA scaffold. As a result of reaction time difference,the introduced-NH2 groups increased continuously along with the longitude of the PLLA scaffold in the z-direction. After covalent immobilization of gelatin by glutaraldehyde coupling,the gelatin gradient scaffold was thus obtained. In vitro chondrocyte culture showed that the cells had higher viability and more extending morphology in the gelatin gradient scaffold than that in the uniform gelatin control.

  18. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Andreasen, Casper Schousboe; Aage, Niels;

    in the solid are [3-6]. The developed methodology is applied to several two-dimensional solid-fluid thermal interaction problems, such as cooling of electronic components and heat exchangers, as well as to the design of micropumping devices based on natural convection effects. The implementation utilises...... solving the isothermal incompressible Navier-Stokes equations. The tightly coupled problems are natural convection problems, where the Boussinesq approximation has been applied to couple the temperature and velocity fields both ways. All of the considered flows are assumed to be laminar and steady.......The work focuses on applying topology optimisation to forced and natural convection problems in fluid dynamics and conjugate (fluid-structure) heat transfer. To the authors' knowledge, topology optimisation has not yet been applied to natural convection flow problems in the published literature...

  19. Biomedical monitoring of phosphate removal by hemodialysis.

    Science.gov (United States)

    Michalec, Michał; Fiedoruk-Pogrebniak, Marta; Matuszkiewicz-Rowińska, Joanna; Tymecki, Łukasz; Koncki, Robert

    2016-07-15

    A compact flow analysis system for non-invasive, dialysate-side monitoring of phosphate removal in the course of clinical hemodialysis treatment is presented. The monitor is based on solenoid operated micro-pumps and extremely cheap optoelectronic flow-through detector allowing photometric determination of phosphate in spent dialysate using a molybdenum blue method. The monitor can operate in both, discrete and continuous modes of measurement. The analytical utility of monitor has been tested with samples of spent dialysate produced by artificial kidney in the course of real hemodialysis sessions. The results of monitoring are comparable with those obtained using reference off-line method recommended for clinical analysis. Additionally, the possibility of two-side (dialysate and blood) monitoring of hemodialysis treatments with optoelectronic flow-through detectors has been announced. PMID:27136282

  20. Solution of Two-Dimensional Viscous Flow Driven by Motion of Flexible Walls

    Directory of Open Access Journals (Sweden)

    Mohamed Gad-el-Hak

    2010-03-01

    Full Text Available An exact solution of the Navier–Stokes equations for a flow driven by motion of flexible wall is developed. A simple two-dimensional channel with deforming walls is considered as domain. The governing equations are linearized for low Reynolds number and large Womersley number Newtonian flows. Appropriate boundary conditions for general deformation are decomposed into harmonic excitations in space by Fourier series decomposition. A model of harmonic boundary deformation is considered and results are compared with computational fluid dynamics predictions. The results of velocity profiles across the channel and the centerline velocities of the channel are in good agreement with CFD solution. The analytical model developed provides quantitative descriptions of the flow field for a wide spectrum of actuating frequnecy and boundary conditions. The presented model can be used as an effective framework for preliminary design and optimization of displacement micropumps and other miniature applications.