Pressure-driven flow in open fluidic channels

Abstract

The miniaturization and integration of electronic circuitry has not only made the enormous increase in performance of semiconductor devices possible but also spawned a myriad of new products and applications ranging from a cellular phone to a personal computer. Similarly, the miniaturization and integration of chemical and biological processes will revolutionize life sciences. Drug design and diagnostics in the genomic era require reliable and cost effective high throughput technologies which can be integrated and allow for a massive parallelization.Microfluidics is the core technology to realize such miniaturized laboratories with feature sizes on a submillimeter scale. Here, we report on a novel microfluidic technology meeting the basic requirements for a microfluidic processor analogous to those of its electronic counterpart: Cost effective production, modular design, high speed, scalability and programmability.Microfluidic systems miniaturize chemical and biological processes on a submillimeter scale. Reducing the dimensions of macroscopic biological or chemical laboratories is advantageousfor the following reasons: The small scale allows for the integration of various processes on one chip analogous to integrated microelectronic circuitry. Thus manual handling, e.g. when transferring reagents from one process step to the next, can be reduced. Such an integration is the prerequisite for a fully automated data management system covering all steps of a given chemical or biological process. Furthermore, the required reagent volumes are reduced thus saving both material costs and process time as many of the time consuming amplification steps for biological substances can be omitted. Finally, the miniaturization results in enhanced precision by providing more homogenous reaction conditions and in shorter times for diffusion driven reactions.

Stability of flowing open fluidic channels

“…21 The width of the channel is defined by the slide thickness (1.0 mm); and the length, by hydrophobic tape wrapped around each end of the slide and the location of the two needles which deliver and extract the fluid. The needles are at inclined angles to the channel.…”

“…20 Alternatively a raised platform can be used, this impedes wetting beyond the platform due to the large range in contact angle which can be supported by a sharp, external edge. [21][22][23] Most studies of open channels are concerned with wetting phenomena in the absence of bulk fluid flow. There are some exceptions, 21,24,25 in which, flowing open channels are considered.…”

“…[21][22][23] Most studies of open channels are concerned with wetting phenomena in the absence of bulk fluid flow. There are some exceptions, 21,24,25 in which, flowing open channels are considered. The motivation for this work into flowing open channels is derived from the advantages of easy external access to the fluid in the open channel allowing the introduction of fluid or solid samples, by having a flow the fluid can then enter an enclosed channel for subsequent sample analysis.…”

“…21,29 This a Author to whom correspondence should be addressed. Electronic mail: adrian.neild@monash.edu 2158-3226/2013/3(2)/022121/12 C Author(s) 2013 3, 022121-1 work will apply the latter to an open channel; as with the majority of small scale fluidic systems, the flow will be governed by an external syringe pump.…”

“…The narrower structure is similar to that used in our previous work 21 and is used to investigate the mechanics of open flow. The wider structure is of interest as the type of film created offers large liquid-air interaction for potential capture of air-borne samples.…”