Fluidic Multiplexer

Secondary screening is carried out in parallel fixed-bed reactors sized for catalyst loadings between 15 and 500 mg. The system is a 48-channel reactor consisting of six modules of eight reactor wells. Six channels are analyzed in parallel and stream selection valves provide fluidic multiplexing between reactor vials and analytical hardware. A typical system is shown in Fig. 3.11. 

Fluidic multiplexer Fluidic sequencing circuits Definition... 

Fig. 16.2 Nanoscale optofluidic sensor arrays (NOSA). (a) 3D illustration of a NOSA sensing element. It consists of a ID photonic crystal microcavity, which is evanescently coupled to a Si waveguide, (b) The electric field profile for the fundamental TE mode propagating through an air clad Si waveguide on SiOi. (c) SEM of a NOSA device array. It illustrates how this architecture is capable of two dimensional multiplexing, thus affording a large degree of parallelism, (d) Actual NOSA chip with an aligned PDMS fluidic layer on top. Reprinted from Ref. 37 with permission. 2008 Optical Society of America...

In recent years, rapid advancements in photonic technologies have significantly enhanced the photonic bio/chemical sensor performance, especially in the areas of (1) interaction between the light and analyte, (2) device miniaturization and multiplexing, and (3) fluidic design and integration. This has led to drastic improvements in sensor sensitivity, enhanced detection limit, advanced fluidic handling capability, lower sample consumption, faster detection time, and lower overall detection cost per measurement. 

Given the sensitive, label-free, and multiplexed analysis that MS can provide and the automated, low-volume fluidic operations enabled by microfluidics, the combination of microfluidics with ESI-MS is expected to see increased use for chemical and biochemical analyses in the years to come. In particular, the ability of microfluidics to process minute volumes and perform sample handling operations in a high-throughput, automated fashion can extend MS-based proteomics and metabolomics studies to samples that are too small for current processes, including in-depth chemical analysis of single cells. 

The approach typical for modern microfluidic systems, which is cheaper, faster and less prone to failure, is characterised by the reactor outputs directly connected to the analyser by means of a system of channels or cavities. Again, an essential part is the sampling unit between the reactors and the analyser. In its fluidic version, sometimes called a fluidic selector or multiplexer, it is an array of valves which open, one by one, the passage leading to... 

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