Micro check valves for integration into polymeric microfluidic devices

Nguyen, Nam‐Trung; Truong, Thai-Quang; Wong, K.W.; Ho, Soon-Seng; Low, Cassandra Lee-Ngo

doi:10.1088/0960-1317/14/1/309

Cited by 94 publications

(81 citation statements)

References 18 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several novel approaches that have been utilized in microfluidic actuators/valves include hydraulically-actuated valves [11]; phase change valves operating with paraffin [12] and ice [13,14]; passive valves that take advantage of variations in surfaces' wetting properties [15]; check valves [16]; and viscosity-controlled valves. The latter types of valves operate with specialized fluids that change their viscosity in response to external stimuli such as temperatureresponsive pluronic solution [17] and a ferrofluid that responds to magnetic-field variations [18].…”

Section: Introductionmentioning

confidence: 99%

Self-Actuated, Thermo-Responsive Hydrogel Valves for Lab on a Chip

Wang

Chen

Mauk

et al. 2005

Biomed Microdevices

145

108

View full text Add to dashboard Cite

An easy to fabricate, thermally-actuated, self-regulated hydrogel valve for flow control in pneumatically driven, microfluidic systems is described. This microvalve takes advantage of the properties of the hydrogel, poly(Nisopropylacrylamide), as well as the aqueous fluid itself to realize flow control. The valve was designed for use in a diagnostic system fabricated with polycarbonate and aimed at the detection of pathogens in oral fluids at the location of the sample collection. The paper describes the construction and characterization of the hydrogel valves and their application for flow control, sample and reagent metering, sample distribution into multiple analysis paths, and the sealing of a polymerase chain reaction (PCR) reactor to suppress bubble formation. The hydrogel-based flow control is electronically addressable, does not require any moving parts, introduces minimal dead volume, is leakage and contaminant free, and is biocompatible. KeywordsMicrovalve, microfluidics, hydrogel, lab-on-a-chip, metering, distribution, PCR Wang, J., Chen, Z., Mauk, M., Hong, K-S, Li, M., Yang, S., and Bau, H., H Wang, J., Chen, Z., Mauk, M., Hong, K-S, Li, M., Yang, S., and Bau, H., H., 2005, Self-Actuated, ThermoResponsive Hydrogel Valves for Lab on a Chip, Biomedical Microdevices 7 (4), 313-322.., 2005, Self-Actuated, Thermo-Responsive Hydrogel Valves for Lab on a Chip, Biomedical Microdevices 7 (4), 313-322. ABSTRACTAn easy to fabricate, thermally-actuated, self-regulated hydrogel valve for flow control in pneumatically driven, microfluidic systems is described. This microvalve takes advantage of the properties of the hydrogel, poly(N-isopropylacrylamide), as well as the aqueous fluid itself to realize flow control. The valve was designed for use in a diagnostic system fabricated with polycarbonate and aimed at the detection of pathogens in oral fluids at the location of the sample collection. The paper describes the construction and characterization of the hydrogel valves and their application for flow control, sample and reagent metering, sample distribution into multiple analysis paths, and the sealing of a polymerase chain reaction (PCR) reactor to suppress bubble formation. The hydrogel-based flow control is electronically addressable, does not require any moving parts, introduces minimal dead volume, is leakage and contaminant free, and is biocompatible.

show abstract

Section: Introductionmentioning

confidence: 99%

Self-Actuated, Thermo-Responsive Hydrogel Valves for Lab on a Chip

Wang

Chen

Mauk

et al. 2005

Biomed Microdevices

145

108

View full text Add to dashboard Cite

show abstract

“…For example, the mechanical properties of SU-8 have been exploited to make check valves. 19 Its surface properties have been exploited to make capillary electrophoresis chips. 20 Its ease of precise patterning has enabled the fabrication of electrospray tips.…”

Section: B Exploration Of Alternative Polymeric Materialsmentioning

confidence: 99%

A practical guide for the fabrication of microfluidic devices using glass and silicon

Iliescu¹,

Taylor²,

Avram³

et al. 2012

Biomicrofluidics

302

207

View full text Add to dashboard Cite

This paper describes the main protocols that are used for fabricating microfluidic devices from glass and silicon. Methods for micropatterning glass and silicon are surveyed, and their limitations are discussed. Bonding methods that can be used for joining these materials are summarized and key process parameters are indicated. The paper also outlines techniques for forming electrical connections between microfluidic devices and external circuits. A framework is proposed for the synthesis of a complete glass/silicon device fabrication flow. I. WHY USE SILICON AND GLASS IN MICRO-AND NANO-FLUIDIC APPLICATIONS?Micro-and nano-fluidic technology continues to be embraced by biologists, 1-3 chemists, 4 and engineers throughout academia and industry. As its applications have expanded, there has been an explosion in the range of materials and processes used to fabricate these devices. The earliest microfluidic devices (e.g., gas 5 and liquid 6 chromatography devices) were made from silicon and glass and borrowed processes directly from semiconductor and microelectromechanical systems (MEMS) manufacturing. 7 Now, however, many researchers have moved away from silicon and glass, and instead use cast elastomers such as polydimethylsiloxane (PDMS)-which is ideal for swift prototyping-or thermoplastic polymers, which can be hot-embossed or injection-molded and are well suited to inexpensive manufacturing. Yet, there remain many applications where glass and silicon offer advantages over polymeric materials. In this paper, we highlight these advantages and offer a framework for selecting fabrication processes when using silicon and glass. A. The dominance of soft lithographyOver the last decade, PDMS has become virtually the default material for forming microfluidic devices, 8 because of the sheer ease with which it can be cast on to a micro-scale mould and then strongly bonded to glass. 9 The elastomeric nature of the material has been exploited to integrate fluidic valves and pumps on-chip and has simplified the production of multi-layer devices because the soft layers readily conform to each other. 10,11 Yet, the low stiffness (usually <1 MPa) of PDMS relative to amorphous thermoplastics, silicon, and glass has its own a) Authors to whom correspondence should be addressed. Electronic addresses: ciliescu@ibn.a-star.edu.sg and hkt@ntu.edu.sg. 6, 016505 (2012) drawbacks. High aspect-ratio channels are notoriously difficult to fabricate in PDMS because of their propensity to collapse. 12 Moreover, difficulties in automating the handling of such a soft material have hampered efforts to scale up PDMS device manufacturing. Meanwhile, PDMS's high oxygen and water permeabilities have proved both a blessing and a curse in different applications.The hydrophobic nature of PDMS can be an important consideration for some biological applications. In drug screening applications, for example, hydrophobic drugs as well as metabolites (urea or albumin) can be absorbed into the device's material due to hydrophobic--hydrophobic interaction...

show abstract

“…During sucking process, the chamber volume increases, the inlet valve opens, outlet valve closes, the fluid gets into the chamber; during the discharging process, the chamber volume decreases, the outlet valve opens, inlet valve closes, the fluid gets out of the chamber. Cycle by cycle, the flow reaches in one direction [4,[13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2015

View full text Add to dashboard Cite

Abstract: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%.

show abstract

Micro check valves for integration into polymeric microfluidic devices

Cited by 94 publications

References 18 publications

Self-Actuated, Thermo-Responsive Hydrogel Valves for Lab on a Chip

Self-Actuated, Thermo-Responsive Hydrogel Valves for Lab on a Chip

A practical guide for the fabrication of microfluidic devices using glass and silicon

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

Contact Info

Product

Resources

About