A MEMS thermopneumatic silicone rubber membrane valve

Yang, Xing; Grosjean, C.; Tai, Yu‐Chong; Ho, Chih‐Ming

doi:10.1016/s0924-4247(97)01660-9

Cited by 61 publications

(44 citation statements)

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“…A number of advantageous microf luidic pumps and valves have been demonstrated previously. Most notably, pneumatic͞hydraulic pumps and valves using multilayer soft lithography (25) and micromachined pumps and valves (23,27,28) can be more closely spaced than Braille pins and arranged entirely arbitrarily. However, Braille displaybased microf luidic systems have six characteristics that make them especially versatile.…”

Section: Resultsmentioning

confidence: 99%

“…In the past, fluidic control included syringe pumps (11), hydrogel valves (12), gravity-driven pumps (13), evaporation-based pumps (14,15), acoustic pumps (16), gas-generationbased pumps (17,18), and centrifugal force in CD chips (19). Electrokinetic flow (20)(21)(22), thermopneumatic (23,24), pneumatic͞hydraulic (25), or mechanical (26,27) valves and pumps have a high degree of control, but require external connection lines to larger equipment for actuation. A few fully integrated and self-packaged systems (23,28) have been developed, but lack the reconfigurability inherent with numerous active valves and pumps.…”

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confidence: 99%

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Computerized microfluidic cell culture using elastomeric channels and Braille displays

Zhu

Futai

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

373

312

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Computer-controlled microfluidics would advance many types of cellular assays and microscale tissue engineering studies wherever spatiotemporal changes in fluidics need to be defined. However, this goal has been elusive because of the limited availability of integrated, programmable pumps and valves. This paper demonstrates how a refreshable Braille display, with its grid of 320 vertically moving pins, can power integrated pumps and valves through localized deformations of channel networks within elastic silicone rubber. The resulting computerized fluidic control is able to switch among: (i) rapid and efficient mixing between streams, (ii) multiple laminar flows with minimal mixing between streams, and (iii) segmented plug-flow of immiscible fluids within the same channel architecture. The same control method is used to precisely seed cells, compartmentalize them into distinct subpopulations through channel reconfiguration, and culture each cell subpopulation for up to 3 weeks under perfusion. These reliable microscale cell cultures showed gradients of cellular behavior from C2C12 myoblasts along channel lengths, as well as differences in cell density of undifferentiated myoblasts and differentiation patterns, both programmable through different flow rates of serumcontaining media. This technology will allow future microscale tissue or cell studies to be more accessible, especially for highthroughput, complex, and long-term experiments. The microfluidic actuation method described is versatile and computer programmable, yet simple, well packaged, and portable enough for personal use.pump ͉ valve ͉ bioreactor ͉ mixer ͉ perfusion A dvanced microfluidic cellular assays (1-6) and microscale tissue engineering studies (7-10) would benefit from robust and convenient methods to computer-control accurate spatiotemporal patterns of microfluidic flows in arrays of fluidic networks. In the past, fluidic control included syringe pumps (11), hydrogel valves (12), gravity-driven pumps (13), evaporation-based pumps (14, 15), acoustic pumps (16), gas-generationbased pumps (17, 18), and centrifugal force in CD chips (19). Electrokinetic flow (20-22), thermopneumatic (23, 24), pneumatic͞hydraulic (25), or mechanical (26, 27) valves and pumps have a high degree of control, but require external connection lines to larger equipment for actuation. A few fully integrated and self-packaged systems (23, 28) have been developed, but lack the reconfigurability inherent with numerous active valves and pumps.Here, we report a method to precisely control fluid flow inside elastomeric capillary networks by using multiple (tens to hundreds) computer-controlled, piezoelectric, movable pins. These pins are positioned as a grid on a refreshable Braille display (e.g., F. H. Papenmeier, Schwerte, Germany), which is a tactile device used by the visually impaired to read computer text. Each pin can act as a valve and be shifted upward to push against channels contained in silicone rubber and completely shut the channel. Three sequential valves of this...

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Computerized microfluidic cell culture using elastomeric channels and Braille displays

Zhu

Futai

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

373

312

View full text Add to dashboard Cite

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“…1(a), the valve is composed of a seat (1), a spider-spring (2), an o-ring (3), an intermediate ring (4) and a lid (5). The principle of the spider-spring is explained in detail in [12].…”

Section: Valve Structurementioning

confidence: 99%

“…They exist in various working principles and designs as presented in [2,3,4]. Recent advances in microtechnology are contributing to design smaller size, higher pressure valves.…”

Section: Introductionmentioning

confidence: 99%

Fluid flow modelling of a micro-valve

Smal

Raucent

Jeanmart

2009

Int. J. Simul. Multidisci. Des. Optim.

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“…They exploit a variety of both mechanical and chemical actuation principles, such as external pressure sources [7], [8], stimuli responsive polymers [9]- [11], centrifugal forces on a rotating disk [12], electrochemical gas generation through electrolysis [13], [14], decomposition of hydrogene peroxide [15] or azobis isobutyronitrile [16], melting of paraffin [17], thermal expansion of gas [18], [19], or expansion of a condensed gas encapsulated in chemically inert microspheres [20].…”

mentioning

confidence: 99%

Liquid Aspiration and Dispensing Based on an Expanding PDMS Composite

Samel

Sandström

Griss

et al. 2008

J. Microelectromech. Syst.

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Abstract-In this paper, we present the development of active liquid aspiration and dispensing units designed for vertical, as well as lateral, liquid aspiration. The devices are based on a single-use thermally expanding polydimethylsiloxane (PDMS) composite, which allows altering its surface topography by means of individually addressable integrated heaters. Devices are designed in order to create an enclosed cavity in the system, due to locally expanding the initially unstructured composite. This enables negative volume displacement and leads to the event of liquid aspiration. To enable this device functionality, two different techniques of selectively creating permanent PDMS bonds have been developed. One approach utilizes the plasma-assisted PDMS bonding technique, together with a patterned antistiction layer to form reversibly, as well as irreversibly, bonded regions. Another approach utilizes microcontact printing of PDMS curing agent, which serves as a patterned intermediate layer for adhesive bonding. Fabricated prototype devices successfully demonstrated the aspiration and release of liquid volumes ranging from 28 to 815 nL. The devices are entirely fabricated from low-cost materials, using wafer-level processes only and do not require external means for liquid actuation.

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A MEMS thermopneumatic silicone rubber membrane valve

Cited by 61 publications

References 1 publication

Computerized microfluidic cell culture using elastomeric channels and Braille displays

Computerized microfluidic cell culture using elastomeric channels and Braille displays

Fluid flow modelling of a micro-valve

Liquid Aspiration and Dispensing Based on an Expanding PDMS Composite

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