bearings will be important in the development of micro- coolers, micropumps, microgenerators, and other

Recent experiments have demonstrated that AC electrokinetic micropumps permit integrable, local, and fast pumping (velocities � 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 ...

This paper investigates the phenomenon of Faradaic charging in ac electrokinetics. Faradaic reactions were suggested as a key effect responsible for the reversal of pumping direction in ac micropumps. However, this hypothesis has yet to be proven convincingly and directly. Here we present an ion detection strategy ...

The AC electrokinetic movement of fluids has its origin in two different physical mechanisms: AC electroosmosis, the interaction of the Electrical Double Layer induced on microelectrodes by an applied potential and the generated electric field; and electrothermal Electro-hydrodynamics, the interaction of an electric field with ...

Lab-on-a-chip devices require integrated pumping and fluid control in microchannels. A recently developed mechanism that can produce fluid flow is an integrated ac-electro-osmosis micropump. However, like most electrokinetic pumps, ac-electro-osmotic pumps are incapable of ...

Various electrokinetic phenomena in microfluidics have been utilised to manipulate microfluids and particles for lab-on-a-chip applications. Microfluidic channels with traditional planar floor configuration designs have limited pumping efficiency due to the fast backward flow over the electrode surface. This study reports optimal design of a microchannel ...

Recent experiments have demonstrated that ac electrokinetic micropumps permit integrable, local, and fast pumping (velocities �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 ...

unsuitable for biological applica- tions. Due to such drawbacks, the use of electrokinetic EK micropumps- clude dc and ac micropumps. In a dc pump electro-osmotic EO flow is induced by an external tangential of directed flow over the activated micropump. For more information on EPAPS, see http://www. aip

A microfluidic pump and mixer design based on ac faradaic polarization is proposed. Unlike ac electrokinetic devices based on capacitive charging of the electrodes, the design yields a net electro-osmotic flow for high-conductivity electrolytes at high voltages and frequencies without producing gas bubbles or ...

Nonlinear electrokinetic pumps are attractive in the development of portable and flexible microfluidic analysis systems, since they operate without moving parts using low (battery powered) alternating potentials. Since the discovery of AC electro-osmosis (ACEO) in the late 1990s, there has been much work in designing and building ...

... Electrokinetic Pumping. ... of experiments carried out on an electrokinetic pump using water as ... with the serious use of such devices as fluid pumps. ...

Rapid cell separation and collection is demonstrated through the integration of electrokinetic pumps, dielectrophoretic (DEP) traps and field driven valves into a well designed microfluidic channel loop. We present the ground-up design and analysis of this fully functional microfluidic device for the rapid separation and collection of live and dead yeast ...

We are developing AC electrokinetic micropumps to drive electrically conductive biological fluids in microchannels. These pumps work on the principles of Induced Charge Electroosmosis (ICEO) and flow Field Effect Transistor (flowFET) phenomena. AC (as well as DC) electric fields can induce electrical double layer ...

An AC electrokinetic funnel flow is generated by a planar micro-coil resister design capable of sustaining 3500V without Faradaic reactions. The final line of the serpentine coil exhibits a transverse electro-osmotic slip velocity exceeding 1 cm/sec. Due to side boundaries, a large back pressure is established in the slip direction to produce an intense ...

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 ...

Flow patterns with both recirculating and unidirectional characteristics are useful for controlled mixing and pumping within microfluidic devices. We have developed a fabrication process that converts injection-molded polymer chips into devices that demonstrate induced-charge electroosmosis (ICEO) effects (1,2) in AC fields. Polymeric insulating posts are ...

concentrator, micro-pumps and mixers by ACEO. Electro-osmosis typically refers to using DC potential to moving is important for optimizing the micropump and particle transportation. In contrast to electrophoretic AC Electrochemical Micropump, AIChE annual meeting 2004, Nov. 7 � 12, Austin, TX. 361 #12;

DESIGN AND MODELING OF A PETAL-SHAPE, CONJUGATED POLYMER-ACTUATED MICROPUMP Yang Fang and Xiaobo the micropump, it is important to make the prototypes of different diaphragms for comparisons and predict the performance of the micropump. In this paper, a petal-shape design is proposed for the pump- Proceedings

This paper reports dramatic improvements in flow rate over conventional alternating current (ac) electrokinetic micropumps by exploiting asymmetry in electric potentials over the electrodes. A micropump consisting of a planar asymmetric electrode array was tested using ac signals with and without a direct current (dc) bias. All ...

ac electro-osmosis (ACEO) has emerged recently as a promising strategy for fluid transport at microscale. With an array of planar interdigital electrodes immersed in an electrolyte, different charging mechanisms at electrode/electrolyte interface and electrokinetic surface flows can be induced by nonuniform electrical fields. To implement ACEO micropump, ...

We have built a dedicated lab on a chip to study the performance of an integrated electrokinetic micropump, driven by a low voltage AC signal. This micropump consists of an array of interdigitated electrodes and is here integrated in a microfluidic loop. We demonstrate that this device can pump continuously and reproducibly electrolyte ...

This SBIR Phase I Research Proposal seeks to develop a new phenomena, high pressure electrokinetic (HPEK)pumping, for the development of high force, compact ...

A method for eliminating gas bubble blockage of current flow during operation of an electrokinetic pump. By making use of the ability to modify the surface charge on the porous dielectric medium used in electrokinetic pumps, it becomes possible to place electrodes away from the pressurized region of the ...

Alternating current (AC) electrokinetic motion of colloidal particles suspended in an aqueous medium and subjected to a spatially nonuniform AC electric field are examined using a simple theoretical model that considers the relative magnitudes of dielectrophoresis, electrophoresis, AC-electroosmosis, and Brownian ...

AC electrokinetics has shown great potential for microfluidic functions such as pumping, mixing and concentrating particles. So far, electrokinetics are typically applied on fluids that are not too conductive (<0.02 S/m), which excludes most biofluidic applications. To solve this problem, this paper seeks to ...

... 4. TITLE AND SUBTITLE Biosensor Assay Enhancement Through Ac ... useful in portable field-based medical biosensors, or environmental, or food ...

Flow and ionic transport in porous media are central to electrokinetic pumping as well as to a host of other microfluidic devices. Electrokinetic pumping provides the ability to create high pressures (to over 10,000 psi) and high flow rates (over 1 mL/min) with a device having no moving parts and all liquid seals. ...

Flow patterns with both recirculating and unidirectional characteristics are useful for controlled mixing and pumping within microfluidic devices. We have developed a fabrication process that converts injection-molded polymer chips into devices that demonstrate induced-charge electroosmosis (ICEO) effects (1,2) in AC fields. Polymeric insulating posts are ...

Alternating current (ac) electrokinetic motion of colloidal particles suspended in an aqueous medium and subjected to a spatially nonuniform ac electric field are examined using a simple theoretical model that considers the relative magnitudes of dielectrophoresis, electrophoresis, ac-electroosmosis, and Brownian ...

The control and handling of fluids and fluid-based samples is central to the majority of applications in the areas of Micro Analysis systems and the Lab-on-a-chip. As a result, there is a great deal of research and industrial interest in developing specific technologies for this purpose: micropumps, micromixers, microstirrers, etc. One widely used technology in these systems is ...

Orthogonal electrodes have been reported to produce high velocity microflows when excited by ac signals, showing potential for micropumping applications. This paper investigates the microflow reversal phenomena in such orthogonal electrode micropumps. Three types of microflow fields were observed by changing the applied electric signals. Three ac ...

ii The goal of the present thesis has been to investigate ways of controlling and manipulating fluids and suspensions in microfluidic systems. In particular, we focus on a theoretical description of AC electroosmotic micropumps with asymmetric electrode arrays, that have recently been demonstrated to permit fast pumping (velocities ? mm/s) with low driving ...

/s)U O ACEO (AC electroosmosis) #12;AC electroosmotic pump Advantages � ~1V (less than 5V) DCEO pump ACEO

A method for altering the surface properties of a particle bed. In application, the method pertains particularly to an electrokinetic pump configuration where nanoparticles are bonded to the surface of the stationary phase to alter the surface properties of the stationary phase including the surface area and/or the zeta potential and thus improve the ...

The precise control and manipulation of small masses of liquids is an important requirement in the lab-on-a-chip technology. Net fluid flows induced by ac potentials applied to arrays of co-planar interdigitated microelectrodes are reported. Two types of microelectrode structures have been studied: arrays of unequal width electrodes subjected to a single ...

A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is ...

pump for liquid helium transfer in space. The pump is made up of an a.c. induction ... for head and flow by testing the pump in liquid helium. Calculations ...

... microstirring is a tool that can be incorporated in existing devices, to speed up, for example, food-borne pathogen detection, or portable medical ...

Khusid geyt Tantsn (klezmer) � Adolf Schreiner (1847-1921), Immer Kleiner Aldert Prast, accordeon, en

In this work, invoking join asymmetric ac polarization using double half-quadrupole electrodes in a symmetric arrangement, we demonstrate a head-on ac electro-osmotic streaming capable of focusing and trapping DNA molecules efficiently. This is manifested by the observation that picomolar DNA molecules can be trapped into a large crosslike spot with at ...

Electrokinetic boundary conditions are derived for ac electrokinetic phenomena over leaky dielectric (i.e., semiconducting) surfaces. Such boundary conditions correlate the electric potentials across a semiconductor-electrolyte interface (consisting of an electric double layer inside the electrolyte solution and a space charge layer ...

Electrokinetic boundary conditions are derived for ac electrokinetic phenomena over leaky dielectric (i.e., semiconducting) surfaces. Such boundary conditions correlate the electric potentials across a semiconductor-electrolyte interface (consisting of an electric double layer inside the electrolyte solution and a space charge layer ...

The field of AC electrokinetics is rapidly growing due to its ability to perform dynamic fluid and particle manipulation on the micro- and nano-scale, which is essential for Lab-on-a-Chip applications. AC electrokinetic phenomena use electric fields to generate forces that act on fluids or suspended particles ...

... Adjustable Speed Drives (ASD), AC induction motors, AC synchronous motors, centrifugal pumps, and positive displacement pumps were ...

A microstirring tool is developed to improve binding rates in biosensor devices by an order of magnitude. AC electric fields generate fluid motion through the well documented but unexploited phenomenon, Electrothermal Flow, where the circulating flow redi...

Orthogonal electrodes have been reported to produce high velocity microflows when excited by ac signals, showing potential for micropumping applications. This paper investigates the microflow reversal phenomena in such orthogonal electrode micropumps. Three types of microflow fields were observed by changing the applied electric signals. Three ac ...

, universal decay of the mobility with bulk concentration c0, observed in KCl for ACEO micropumps [11. Lett. 100 058302 [10] Olesen L H, Bruus H and Ajdari A 2006 AC electrokinetic micropumps: the effect and Chang H C 2004 Electrokinetic micropump and micromixer design based on ac Faradaic polarization J. Appl

Arguments for using limited leakage pumps instead of canned-motor pumps in rcactor coolant primary systems are given. The literature available on the subject is reviewed. (A.C.)

An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based systems. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing ...

An electrospray apparatus uses a microchannel formed in a microchip. Fluid is pumped through the channel to an outlet orifice using either hydraulic or electrokinetic means. An electrospray is generated by establishing a sufficient potential difference between the fluid at the outlet orifice and a target electrode spaced from the outlet orifice. ...

An electrospray apparatus uses a microchannel formed in a microchip. Fluid is pumped through the channel to an outlet orifice using either hydraulic or electrokinetic means. An electrospray is generated by establishing a sufficient potential difference between the fluid at the outlet orifice and a target electrode spaced from the outlet orifice. ...

An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and ...

An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and ...

In the second part of a series on electromagnetic pumping of liquid metals, the design and characteristics of the a-c conduction pump and the induction pump are discussed. Possible future developments in the pumping of liquld metals are described. (J.S.R.)

A dc current can be pumped through a nanostructure by two out-of-phase ac driving fields. In this approach, we investigate the pumped current properties driven by multiharmonic ac fields in nanowire structures. Considering the first five harmonics, the adiabatically pumping properties driven by ...

The area of 'laboratory-on-a-chip', miniaturised or microfluidic analysis systems, is a rapidly developing field. At the microscale, electrokinetic processes become enhanced, and the advent of AC electrokinetics (EK) in recent years further promotes the development of electrokinetic devices for microfluidics. ACEK ...

The kinesin-microtubule system plays an important role in intracellular transport and is a model system for integrating biomotor-driven transport into microengineered devices. AC electrokinetics provides a novel tool for manipulating and organizing microtubules in solution, enabling new experimental geometries for investigating and controlling the ...

The bulk of this thesis investigates the role of hydrodynamic interactions and electrokinetic effects in colloidal and microfluidic systems. We study the influence of a solid wall upon the correlated diffusive motion of two Brownian spheres, and make predictions which agree with experiments performed at the University of Chicago. We examine experiments which had seemed to ...

This Special Topic section is a compilation of several original contributions covering both fundamental and practical aspects of electrokinetic microfluidic phenomena that were presented during the Electrokinetics and Microfluidics sessions held at the conference. PMID:20644663

This Special Topic section is a compilation of several original contributions covering both fundamental and practical aspects of electrokinetic microfluidic phenomena that were presented during the Electrokinetics and Microfluidics sessions held at the conference.

intensive. Such baffles are also problematic in chips that employ electroosmosis or electrophoresis as high than the linear scaling of the standard electroosmosis. Dukhin7 first offered an estimate to a combination of channel electroosmosis and the pH-gradient-induced backflows, is less significant than that due

AC electrokinetics is rapidly becoming a foundational tool for lab-on-a-chip systems due to its versatility and the simplicity of the components capable of generating them. Predicting the behavior of fluids and particles under non-uniform AC electric fields is important for the design of next generation devices. Though there are ...

We demonstrate an opto-electrokinetic technique for non-invasive particle manipulation on the surface of a parallel-plate indium tin oxide (ITO) electrode that is biased with an alternating current (AC) signal and illuminated with near-infrared (1064 nm) optical landscapes. This technique can generate strong microfluidic vortices at higher ...

Micelles and polymers vesicles have been of increasing interest as drug delivery systems for controlled release, specific cell targeting, and medical diagnostics. In addition, AC-electrokinetic techniques have emerged as a viable option for colloidal and biocolloidal manipulation. In this work, we examine the dielectrophoresis (DEP) characteristics of complex micellar ...

This study reports a hybrid electrokinetic technique for label-free manipulation of pathogenic bacteria in biological samples toward medical diagnostic applications. While most electrokinetic techniques only function in low-conductivity buffers, hybrid electrokinetics enables effective operation in high-conductivity samples, such as ...

This study reports improved electrokinetically driven microfluidic T-mixers to enhance their mixing efficiency. Enhancement of electrokinetic microfluidic T-mixers is achieved using (i) an active approach of utilizing a pulsating EOF, and (ii) a passive approach of using the channel geometry effect with patterned blocks. PDMS-based ...

An ac electric field is applied to induce particle and fluid motion in a wedge-shaped microchannel. Micron-resolution particle image velocimetry (?-PIV) is used to determine spatially resolved particle velocity and fluid velocity fields. Under steady-state conditions, the particles experience a balance between dielectrophoretic forces induced by the nonuniform electric field ...

The ability to generate high pressures using electrokinetic pumping of liquid through porous media is reported. Pressures in excess of 8000 psi have been achieved using capillaries packed with micron-size silica beads. A model is presented which accuratel...

Electrokinetic energy conversion in microfluidic systems is a subject of intense research at present, where the main objective is to improve the thermodynamic efficiency of the process. As a novel strategy to the problem, this work focuses on the fluid dynamic properties of the working fluid. It is shown that polymer solutions with wall depletion can substantially increase the ...

We describe the general phenomenon of �induced-charge electro-osmosis� (ICEO) the nonlinear electro-osmotic slip that occurs when an applied field acts on the ionic charge it induces around a polarizable surface. Motivated by a simple physical picture, we calculate ICEO flows around conducting cylinders in steady (DC), oscillatory (AC), and suddenly applied electric ...

A microfluidic switch has been demonstrated using an AC Magnetohydrodynamic (MHD) pumping mechanism in which the Lorentz force is used to pump an electrolytic solution. By integrating two AC MHD pumps into different arms of a Y-shaped fluidic circuit, flow can be switched between the two arms. ...

The ability to generate high pressures using electrokinetic pumping of liquid through porous media is reported. Pressures in excess of 8000 psi have been achieved using capillaries (< 100 {micro}m i.d.) packed with micron-size silica beads. A model is presented which accurately predicts absolute pressures, flowrates and power conversion efficiencies ...

Pumps with step microelectrodes subjected to an ac voltage are known to have faster pumping rates than those with planar asymmetric microelectrodes. The driving force for pumping in these systems is ac electro-osmosis. This paper aims to understand the flow behaviors of ...

Pumps with step microelectrodes subjected to an ac voltage are known to have faster pumping rates than those with planar asymmetric microelectrodes. The driving force for pumping in these systems is ac electro-osmosis. This paper aims to understand the flow behaviors of ...

Electric field guided assembly of colloids is a new area of research in colloidal science where sub-micrometer particles, or colloids, are assembled using patterned electrodes. The design of these devices is often limited by an inability to characterize accurately forces and fluxes with linearized electrokinetic theory. The research presented in this dissertation describes an ...

A preliminary design study of flight-type dc conduction-permanent magnetic, ac helical induction, and ac linear induction pumps for circulating 883 K (1130 F) NaK at 9.1 kg/sec (20 lb/sec) is described. Various electromagnetic pump geometrics are evaluate...

and proteins. AC electroosmotic flow can be utilized to create micropumps for micro-bio- chips [1]. As a result electroosmotic micropumps. ICEO [4] refers to a phenomenon in which a DC or AC electric field induces charge electrokinetic micropumps: The effect of geometrical confinement, Faradaic current injection, and nonlinear

The overall efficiency of an ac electrically-driven fuel booster pump over a wide range of frequency has been reported in a general performance study. To find the effect of speed on the efficiency of the pump itself, the input-output characteristics of th...

The various technical solutions for solar powered pumping are presented and their feasibility examined: long shaft pumps, submerged motor pumps with DC, AC and electronic motors, and surface pumps. The equipment costs, installation, drilling costs, etc. a...

Microfabrication technology has enabled the application of electrokinetics as a method of performing chemical analyses and achieving liquid pumping in electronically-controlled microchip systems with no moving parts. Electrokinetics involves the interaction of solid surfaces, ionic solutions, and electric fields. Electric fields can be ...

Removal of Cu, Cr and As from utility poles treated with chromated copper arsenate (CCA) was investigated using different one- to three-step combinations of oxalic acid extraction and electrokinetic treatment. The experiments were carried out at room temperature, using 0.8% oxalic acid and 30 V (200 V/m) of direct current (DC) or alternating current in combination ...

Autonomous bio-chemical agent detectors require sample preparation involving multiplex fluid control. We have developed a portable microfluidic pump array for metering sub-microliter volumes at flowrates of 1-100 {micro}L/min. Each pump is composed of an electrokinetic (EK) pump and high-voltage power supply with ...

The present invention relates to an electrokinetic (EK) pump capable of creating high pressures electroosmotically, and capable of retaining high pressures. Both pressure creation and retention are accomplished without the need for moving parts. The EK pump uses a polymerizable fluid that creates the pressure-retaining seal within the ...

The ac free-electron laser (ac FEL) uses an ac (temporally oscillating but spatially uniform) field as the pump source with the hope that electromagnetic radiation will be produced with wavelength shorter than that can be generated by a conventional magnet FEL. The ac field can be provided by a ...

Gas bubble-free electrodes are necessary for stable long-term operation of millimeter-scale electrokinetic (EK) pumps when currents exceed 10-50 .mu.A. An accompanying Technical Advance describes EK pumps that draw 1-3 mA. We have developed gasless and ga...

We present here a study on overlooked aspects of alternating current (AC) electrokinetics-AC electrophoretic (ACEP) phenomena. The dynamics of a particle with both polarizability and net charges in a non-uniform AC electric trapping field is investigated. It is found that either electrophoretic (EP) or dielectrophoretic (DEP) effects ...

We present here a study on overlooked aspects of alternating current (AC) electrokinetics�AC electrophoretic (ACEP) phenomena. The dynamics of a particle with both polarizability and net charges in a non-uniform AC electric trapping field is investigated. It is found that either electrophoretic (EP) or dielectrophoretic (DEP) effects ...

Motivated by the growing interest in ac electroosmosis as a reliable no moving parts strategy to control fluid motion in microfluidic devices for biomedical applications, such as lab-on-a-chip, we study transient and steady-state electrokinetic phenomena (electroosmosis and streaming currents) in infinitely extended rectangular charged microchannels. With ...

The recognition and manipulation of biomolecules on the microscale is a fundamental requirement for the development of lab on a chip devices. AC electrokinetic approaches are ideally suited to manipulating particles in such systems. Unfortunately, these approaches cannot recognize isolated macromolecules with high discrimination because molecular ...

Iontophoretic and electroporation transdermal delivery modes of ionic drugs have been utilized in a number of clinical and biomedical devices. However, applications of these methods have been found challenging for the delivery of many non polar and high molecular weight clinically important drugs. The main goal of the present study is to investigate whether transdermal transport of non polar ...

In this work, we explore the rich AC-electrokinetic effects to manipulate micelles of varied chemical structures and examine their stability in response to applied AC-electric fields. We investigate the AC-field induced transport and instability of sodium dodecyl sulfate (SDS) micelles and cetyl trimethylammonium bromide (CTAB) ...

We report on experiments demonstrating the possibility to pump electrolyte solutions in closed microchannel loops using asymmetric arrays of micro-electrodes addressed with AC voltages. Velocities of a few mm/s can be obtained with voltages of a few Volts in this integrable pumping scheme. The variation of pumping ...

Electromagnetic ac conduction pumps for liquid metals perform better in a three-legged core structure. The physical principles are described, beginning with the transformer with a leakage yoke. The secondary current crosses the pump channel, and the chann...

://www.mof.go.jp/singikai/zaisanfollow_up/siryou/20080515/tepco.pdf CO2 Emission Reduction Potential of Heat Pump in Japan Drying Temp. rise AC Hot water AC water system Solar heat IT Network Household wall insulation Display Top runner appliances Next genSep. 24, 2009 Heat Pump Technology Development in Japan ...

We demonstrate an optically induced electrokinetic technique that continuously concentrates nanoparticles on the surface of a parallel plate electrode that is biased with an AC signal. A highly focused beam of near-infrared light (1064 nm) was applied, inducing an electrothermal microfluidic vortex that carried nanoparticles to its center where they were ...

Motivated by the recent interest in using electrokinetic effects within microfluidic devices, they have extended the EBNavierStokes code to be able to handle electrokinetic effects. With this added functionality, the code becomes more useful for understanding and designing microfluidic devices that take advantage of electrokinetic ...

distinctively ac features. The ac cones show a unique longitudinal growth that result in very high aspect ratio the pump. But even then, the cone growth continued until the meniscus became very slender and unstableAnomalous conical menisci under an ac field-departure from the dc Taylor cone Siddharth Maheshwari

... is a battery-operated suction pump for pharyngeal suctioning during resuscitation emergencies. Batteries are recharged by an ac charger included ...

... 47 6 Dimensions of the Wind Tunnel Components 48 7 Details of the Nozzle Throats 49 8 AC 27D Sliding Vane Vacuum Pumps 50 ...

... One level of checking can be ac=orplished by recirculating A FFF concentrate through the proportioner pump and back into the tank; however, the ...

... Blood is drawn from the donor and into the system by the inlet pump during the collection process. AC and whole blood are mixed ...

Forces experienced by colloidal particles in an AC electric field such as dielectrophoresis (DEP) and AC electro-osmosis (ACEO) have been widely investigated for their application in microfluidic devices. In order to provide a more complete theoretical basis for such AC electrokinetic mechanisms, we propose a ...

The ability of electrokinetics to manipulate biological microparticles, such as cells and bacteria, has great applications in Lab-on-a-chip devices, and micro-total analysis systems (mTAS). In these methods, non-uniform AC electric fields interact with the dielectric properties of suspended biological microparticles to induce forces and torques on the ...

This paper reports on the integration of thick carbon-polydimethylsiloxane (C-PDMS) electrodes in microfluidic systems for electrokinetic operations. The C-PDMS material, obtained by mixing carbon nanopowder and PDMS, preserves PDMS processing properties such as O2 plasma activation and soft-lithography patternability in thick or 3D electrodes. Conductivity in the order of 10 ...

The report gives results of an experimental and theoretical investigation of the transient and steady state performance of a residential air-conditioning/heat pump (AC/HP) operating with different refrigerants. (NOTE: The project was motivated by environm...

The report gives results of an experimental and theoretical investigation of the transient and steady state performance of a residential air-conditioning/heat pump (AC/HP) operating with different refrigerants. (NOTE: The project was motivated by environmental concerns related to...

An evaluation of prospective laser materials for a space-based solar pumped laser system over the past decade has resulted in the identification of the iodine photodissociation laser as that system best suited to solar-pumped high energy operation. The ac...

Microscale electrodes supplied with an AC field can generate rotational fluid patterns known as AC electroosmosis. In the present study, this effect was used to improve antibody binding on a biosensor surface. Antibodies, like many other large, slow moving biomolecules, tend to suffer from transport limitations during a reaction with a surface-bound ...

We have designed and fabricated novel electrokinetic micropumps for producing unidirectional flows in microchannels. These pumps utilize very small voltages (15 Volts) to create significant flow velocities (100 microns/s). Low voltages reduce the problem of electrolysis and bubble formation inside the microchannels. One type of the ...

A polymer material useful as the porous dielectric medium for microfluidic devices generally and electrokinetic pumps in particular. The polymer material is produced from an inverse (water-in-oil) emulsion that creates a 3-dimensional network characterized by small pores and high internal volume, characteristics that are particularly desirable for the ...

Electrokinetic microstirring is used to improve the sensitivity of microfluidic heterogeneous immuno-sensors by enhancing the transport in diffusion-limited reactions. The AC electrokinetic force, Electrothermal Flow, is exploited to create a circular stirring fluid motion, thereby providing more binding opportunities between suspended ...