A circular ac magnetohydrodynamic micropump for chromatographic applications

Eijkel, Jan C.T.; Dalton, Colin; Hayden, Chris; Burt, Julian P.H.; Manz, Andreas

doi:10.1016/s0925-4005(03)00267-3

Cited by 96 publications

(69 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 depicts the response time of the valve as a function of the precooling time when the power supply to the thermoelectric unit was 3.3 W and the pressure head was 5.7 kPa. At room temperature, this pressure head corresponded to a flow rate of 118 mL min 21 . Once cooling started, the liquid viscosity increased and the flow rate decreased.…”

Section: Characterization Of the Pc Valvementioning

confidence: 99%

“…A control run was carried out in a standard bench-top PCR thermocycler (Techne Incorporated, Princeton, NJ). Both the control and on-chip PCR were carried out with the same reagents: 50 mM Tris-HCl (pH 9.0), 20 mM (NH 4 ) 2 SO 4 , 1.5-3.5 mM MgCl 2 , 200 mM of dNTP, and 0.1 mg mL 21 BSA, 1.2 mM and 0.7 mM F-and R-Primers, 6.5 ng mL 21 DNA template, and 0.2 U mL 21 Taq. The thermal cycling protocol consisted of an initial denaturation at 94 uC for 120 s, 25 cycles (94 uC, 20 s; 55 uC, 20 s; 72 uC, 20 s), and a final extension at 72 uC for 120 s. After the amplification, both the products of the positive control and the chip-based PCR were electrophoresed in 1% agarose gel.…”

Section: Stationary Pcrmentioning

confidence: 99%

“…In certain applications such as magneto-hydrodynamically (MHD) driven circular chromatography, 21 MHD-driven PCR, 22 MHD stirrer, 23 and self-actuated flow-cycling PCR, 24,25 it is desirable to flow reagents in a closed loop. In a pneumatic system, the filling of the closed loop without creating gas bubbles represents a challenge.…”

Section: Filling and Withdrawing Samples From A Closed Loopmentioning

confidence: 99%

See 2 more Smart Citations

Thermally-actuated, phase change flow control for microfluidic systems

et al. 2005

View full text Add to dashboard Cite

An easy to implement, thermally-actuated, noninvasive method for flow control in microfluidic devices is described. This technique takes advantage of the phase change of the working liquid itself-the freezing and melting of a portion of a liquid slug-to noninvasively close and open flow passages (referred to as a phase change valve). The valve was designed for use in a miniature diagnostic system for detecting pathogens in oral fluids at the point of care. The paper describes the modeling, construction, and characteristics of the valve. The experimental results favorably agree with theoretical predictions. In addition, the paper demonstrates the use of the phase change valves for flow control, sample metering and distribution into multiple analysis paths, sealing of a polymerase chain reaction (PCR) chamber, and sample introduction into and withdrawal from a closed loop. The phase change valve is electronically addressable, does not require any moving parts, introduces only minimal dead volume, is leakage and contamination free, and is biocompatible. CommentsFor personal or professional use only; May not be further made available or distributed.

show abstract

Section: Characterization Of the Pc Valvementioning

confidence: 99%

Section: Stationary Pcrmentioning

confidence: 99%

Section: Filling and Withdrawing Samples From A Closed Loopmentioning

confidence: 99%

See 1 more Smart Citation

Thermally-actuated, phase change flow control for microfluidic systems

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Redox-based MHD pumping was All values for voltage (U), current (I), channels' cross-sectional area (A), total length of electrodes along the pumping channel (l), MHD flow mean velocity in the pumping channel (v MHD ) and MHD flow rate (Q MHD ) were experimental data, and were taken from Refs. [1,2,6,[8][9][10]. Most of the values for the electrodes cross-sectional area (A J ) and current density (J) across the pumping channel had to be calculated.…”

Section: Introductionmentioning

confidence: 99%

“…studied by Leventis and Gao [6] and more recently by Clark and coworkers [7]. Other groups studied MHD pumping of saline solutions with combined AC magnetic fields and an AC current at high frequencies (≥1 kHz) to avoid bubble formation at the electrodes [8][9][10][11]. MHD pumping in the AC mode leads to low flow rates as a result of the low intensity of the AC magnets.…”

Section: Introductionmentioning

confidence: 99%

Magnetohydrodynamic pumping in nuclear magnetic resonance environments

Homsy

Linder

Lucklum

et al. 2007

Sensors and Actuators B: Chemical

View full text Add to dashboard Cite

We present a DC magnetohydrodynamic (MHD) pump as component of a nuclear magnetic resonance (NMR) microfluidic chip. This is the first time that MHD pumping in an NMR environment was observed and demonstrated. This chip generates a maximum flow rate of 1.5 L min −1 (2.8 mm s −1 in the microchannel) for an applied voltage of 19 V with only 38 mW of power consumption in a 7 T superconductive magnet. We developed a simple method of flow rate measurement inside the bulky NMR magnet by monitoring the displacement of a liquid-liquid interface of two immiscible liquids in an off-chip capillary. We compared and validated this flow measurement technique with another established technique for microfluidics based on the displacement of microbeads. This allowed us to characterize and compare the flow rate generated by the micropump on top of a permanent magnet (B 1 = 0.33 T) with the superconductive magnet (B 0 = 7.05 T). We observed a 21-fold increase in flow rate corresponding to the ratio of the magnetic field intensities (B 0 /B 1 = 21) in accordance with the theoretical flow dependence on the magnetic field intensity. The final aim is to integrate MHD pumps together with planar coils in a microfluidic system for NMR analysis. The high performance of MHD pumps at relatively low flow rates is seen as an asset for NMR and MRI applications.

show abstract

Cyclic electrophoretic and chromatographic separation methods

2004

View full text Add to dashboard Cite

A review is given of the application of cyclic analytical methods in capillary electroseparation (CE) and liquid chromatography (LC) systems. Cyclic methods have been used since the early sixties in chromatographic systems to overcome pressure limitations to resolution. From the early nineties on they have also been applied in capillary electroseparation systems to overcome voltage limitations. Some basic theory is given, outlining the temporal development of resolution in cyclic CE and LC systems and calculating the maximal resolution that can be obtained as a function of the operational parameters of pressure and electrical field. Simple equations are given for the temporal change in the peak capacity and the loss of peaks from the systems as it occurs in some cyclic systems. Finally, a circular open tubular chromatographic system is proposed using integrated pumping and continuous detection. The performance of such a system is discussed using magnetohydrodynamic and alternating current electroosmotic pumping as examples of integrated pumps and Shah Convolution Fourier transform detection as an example of a continuous detection method.

show abstract

A circular ac magnetohydrodynamic micropump for chromatographic applications

Cited by 96 publications

References 18 publications

Thermally-actuated, phase change flow control for microfluidic systems

Thermally-actuated, phase change flow control for microfluidic systems

Magnetohydrodynamic pumping in nuclear magnetic resonance environments

Cyclic electrophoretic and chromatographic separation methods

Contact Info

Product

Resources

About