Centrifugo-dynamic inward pumping of liquids on a centrifugal microfluidic platform

Zehnle, S.; Schwemmer, F.; Roth, Günter; Stetten, Felix von; Zengerle, Roland; Paust, Nils

doi:10.1039/c2lc40942a

Cited by 67 publications

(80 citation statements)

References 24 publications

(35 reference statements)

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“…For example (Zehnle et al 2012) utilized the combination of air compression in ventless chambers and tuning the hydraulic resistance of connecting channels to propel fluid from the outer edge of the disc toward its center. In another approach (Gorkin et al 2012b) proposed the use of negative pressure that is generated within on-disc radial channels as a fluid empties from them.…”

Section: Introductionmentioning

confidence: 99%

Design and implementation of fluidic micro-pulleys for flow control on centrifugal microfluidic platforms

Soroori

Kulinsky

Kido

et al. 2013

Microfluid Nanofluid

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Microfluidic discs have been employed in a variety of applications for chemical analyses and biological diagnostics. These platforms offer a sophisticated fluidic toolbox, necessary to perform processes that involve sample preparation, purification, analysis, and detection. However, one of the weaknesses of such systems is the uni-directional movement of fluid from the disc center to its periphery due to the uni-directionality of the propelling centrifugal force. Here we demonstrate a mechanism for fluid movement from the periphery of a hydrophobic disc toward its center that does not rely on the energy supplied by any peripheral equipment. This method utilizes a ventless fluidic network that connects a column of working fluid to a sample fluid. As the working fluid is pushed by the centrifugal force to move toward the periphery of the disc, the sample fluid is pulled up toward the center of the disc analogous to a physical pulley where two weights are connected by a rope passed through a block. The ventless network is analogous to the rope in the pulley. As the working fluid descends, it creates a negative pressure that pulls the sample fluid up. The sample and working fluids do not come into direct contact and it allows the freedom to select a working fluid with physical properties markedly different from those of the sample. This article provides a demonstration of the “micro-pulley” on a disc, discusses underlying physical phenomena, provides design guidelines for fabrication of micro-pulleys on discs, and outlines a vision for future micro-pulley applications.

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Section: Introductionmentioning

confidence: 99%

Design and implementation of fluidic micro-pulleys for flow control on centrifugal microfluidic platforms

Soroori

Kulinsky

Kido

et al. 2013

Microfluid Nanofluid

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“…We proofed the proper function of VDB's by applying them in a structure for PCR based pre-amplification, which is usually used to achieve lower detection limits in geometrically multiplexed PCR 31,32 or to enable the direct use of crude samples rendering nucleic acid purification redundant 33 . To demonstrate easy integration with further downstream processes, subsequently to the PCR amplification the reaction product is pumped radially inwards employing a centrifugo-dynamic pumping mechanism 34 . The complete integration of microfluidic preamplification significantly lowers the risk of cross-contamination in a laboratory environment that may be caused by manually handling high copy numbers of DNA after amplification.…”

Section: Introductionmentioning

confidence: 99%

Microfluidic vapor-diffusion barrier for pressure reduction in fully closed PCR modules

et al. 2015

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Microfluidic systems for polymerase chain reaction (PCR) should be fully closed to avoid vapor loss and to exclude the risk of contaminating the laboratory environment. In closed systems however, the high temperatures of up to 95 °C associated with PCR cause high overpressures up to 100 kPa, dominated by the increase of vapor partial pressure upon evaporation. Such high overpressures pose challenges to the mechanical stability of microfluidic chips as well as to the liquid handling in integrated sample-to-answer systems. In this work, we drastically reduce the pressure increase in fully closed PCR systems by integrating a microchannel that serves as a vapor-diffusion barrier (VDB), separating the liquid-filled PCR chamber from an auxiliary air chamber. In such configurations, propagation of vapor from the PCR chamber into the auxiliary air chamber and as a consequence the increase of pressure is limited by the slow diffusion process of vapor through the VDB. At temperature increase from 23 °C to 95 °C, we demonstrate the reduction of overpressure from more than 80 kPa without the VDB to only 35 kPa with the VDB. We further demonstrate proper function of VDB and its easy integration with downstream processes for PCR based nucleic acid amplification within centrifugal microfluidics. Without integration of the VDB, malfunction due to pressure-induced delamination of the microfluidic chip occurred.

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“…[10][11][12][13][14][15] These devices enable nonprofessional technicians to perform clinical testing near patients. "Lab-on-a-disk" systems have demonstrated great potential as platforms for POC testing because of their ability to actuate low-volume liquid samples, and perform integrated sample preparation procedures on the disk through microfluidic functions, such as decanting, [16][17][18][19][20] mixing, [21][22][23][24][25][26][27] and aliquoting. 28 In addition, it is possible to use a portable diagnostic instrument similar in size to a compact disk player and an inexpensive disposable assay disk could be made by injection molding.…”

Section: Introductionmentioning

confidence: 99%

A Point-of-Care Prothrombin Time Test on a Microfluidic Disk Analyzer Using Alternate Spinning

Lin¹,

Lin²,

Yen³

et al. 2015

j nanosci nanotechnol

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In this study, we conducted a fully integrated point-of-care prothrombin time test on a microfluidic disk analyzer. The microfluidic functions integrated on the disk were capable of separating whole blood, decanting plasma, and mixing it with reagents in sequence under alternate spinning. The assay protocol was completed by alternate spinning without using microvalves or surface modification. Clinical sample tests on prothrombin time measurement were conducted by both the microfluidic disk analyzer and the reference instrument used in medical centers. The test results showed a good correlation and agreement between the two instruments.

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Centrifugo-dynamic inward pumping of liquids on a centrifugal microfluidic platform

Cited by 67 publications

References 24 publications

Design and implementation of fluidic micro-pulleys for flow control on centrifugal microfluidic platforms

Design and implementation of fluidic micro-pulleys for flow control on centrifugal microfluidic platforms

Microfluidic vapor-diffusion barrier for pressure reduction in fully closed PCR modules

A Point-of-Care Prothrombin Time Test on a Microfluidic Disk Analyzer Using Alternate Spinning

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