Microchannel array

Diagram showing a flow of ions of m/z a, b, c, etc. traveling in bunches toward the front face of a microchannel array. After each ion strikes the inside of any one microchannel, a cascade of electrons is produced and moves toward the back end of the microchannel, where they are collected on a metal plate. This flow of electrons from the microchannel plate constitutes the current produced by the incoming ions (often called the ion current but actually a flow of electrons). The ion.s of m/z a, b, c, etc. are separated in time and reach the front of the microchannel collector array one set after another. The time at which the resulting electron current flows is proportional to V m/z). 

As shown above, when an ion arrives at the microchannel array it releases a cascade of electrons onto the back plate. This cascade constitutes an electrical pulse from the microchannel plate, which... 

This timing is done electronically by using a microchannel array ion collector and time bins. The microchannel array sends an electrical pulse to a time bin. Since a pulse is recorded, the ion arrival times are already digitized, hence the name time-to-digital converter (TDC). 

A series of consecutive time bins covers a length of time of a few milliseconds, with each bin representing a time of only a fraction of a nanosecond. When an ion arrives at the microchannel array detector, one time bin notes the resulting electronic pulse. 

Kikuchim, Y., Chun, K., Fujita, H., Micromachined straight-through silicon microchannel array for monodispersed microspheres, in Matlosz, M., Eheeeld,... 

Paul, B. K., Hasan, H., Dewey, T., Ahman, D., Wilson, R. D., Development of aluminide microchannel arrays for high-temperature microreactors and micro-scale heat exchangers, in Proceedings of the 6th International Conference on Microreaction Technology, IMRET 6 (11-14 March 2002), AIChE Pub. 

Yan, K.Y., Smith, R.L., Collins, S.D., Fluidic microchannel arrays for the electrophoretic separation and detection of bioanalytes using electrochemilumines-cence. Biomed. Microdevices 2000, 2(3), 221-229. 

Shi et al. [98] introduced a pressurized capillary array system to simultaneously load 96 samples into 96 sample wells of a radial microchannel array electrophoresis microplate for high-throughput DNA sizing (Figure 13). As a result, 96 samples were analyzed in less than 90 s per microplate, demonstrating the power of microfabricated devices for large-scale and high-performance nucleic acid characterization. 

In conclusion, the advantages of microfluidic devices, parallel synthesis, and combinatorial approaches can be merged to integrate a fluorescent chemical sensor array in a microfluidic chip. Fluorescent microchannel array can be produced by parallel synthesis of fluorescent monolayers covalent attached to the walls of glass microchannels. 

LPC is known to cause hemolysis. This is because LPC incorporates very easily in the erythrocyte cell membrane and weakens the erythrocyte itself. However, this hemolysis depends on the level of LPC concentration. Under low-LPC concentration, hemolysis will not occur. We evaluated the deformability of the erythrocytes when treated with low-concentration DHA-LPC and the DHA-PC by measuring the flow speed of the erythrocytes going through a microchannel array called MC fan (Hosokawa et al. 1995, Nojima et al. 1995). As comparison, flow speed of soy PC-and LPC-incorporated erythrocytes was also measured. 

Ju et al. [2] found evidence of two kinds of unsteady flow boiling for 21 parallel microchannels measuring 231 x 713 pm. They observed in their parallel microchannel array either a global fluctuation of the whole two-phase zone for all the microchannels (Fig. 1) or chaotic fluctuations of the two-phase zone (Fig. 2) overpressure in one microchannel and under-pressure in another. The individual microchannel mass flow rate was not controlled. 

Figure 5b presents the measured variation of the steady-state temperature distribution across the microchannel array imposed by the hot and cold reservoirs computed from an ensemble of 60 instantaneous snapshots of the temperature field across the array as reported in Natrajan and... 

Micromolding, Fig. 9 Examples of embossing tools and structures. SEMs of (a) a microchannel array of a flow cytometry system in PC fabricated with a silicon RIE tool, (b) a high aspect ratio test structure embossed in PC using... 

In conclusion, narrow RTD in multichannel microreactors can only be expected, when the design of gas distributer in front of the microchannel array and the design of the collector behind the channels are optimized. 

Fig. 1 Design of the IMA chip, a. Top view. The device consists of a 2 mm thick PDMS part with microchannels and a 1 mm thick glass plate with An thin-fUm electrodes, h. Magnified view of the channel layout. The 12 I-shaped microchannels are arranged symmetrically with respect to both the horizontal and vertical axes. Each channel is 80 pm wide, 25 pm deep, and 28 mm long. The reservoirs with a diameter of 2 mm are punched in the PDMS part. The cathode is 80 pm wide and 200 nm thick. The anode is 400 pm wide and 200 nm thick. The distance between the cathode and the anode along the microchannels is 14.4 mm. c. Magnified view around the cathode. Each channel has a passive stop valve (8 pm wide and 80 pm long). The distance between adjacent channels (center to center) is 160 pm. The distance between the cathode and the passive stop valves is 0.4 mm. d. Magnified view around the comers of the microchannels. Source From I-shaped microchannel array chip for parallel electrophoretic analyses, in Anal. Chem. Copyright 2007, American Chemical Society.

Inoue, A. Ito, T. Makino, K. Hosokawa, K. Maeda, M. I-shaped microchannel array chip for parallel electrophoretic analyses. Anal. Chem. 2007, 79 (5), 2168-2173. 

The preparation of double emulsions by using MC emulsification was first reported by Kawakatsu et al. [56]. In the first step, a W/O emulsion, which was used as a feed emulsion, was prepared by conventional homogenization. It was then forced into the microchannel array on a silicon substrate to produce a W/O/W emulsion. Solid-in-oil-in-water (S/O/W) pectin microcapsules were also formed by the gelation of the internal aqueous phase - the pectin solution - using a calcium solution containing Tween 20 as an external water phase. 

Multiphase packed-bed or trickle-bed microreactor [29, 30] Standard porous catalysts are incorporated in silicon-glass microfabricated reactors consisting of a microfluidic distribution manifold, a single micro-channel reactor or a microchannel array and a 25-pm microfllter. The fluid streams come into contact via a series of interleaved high aspect ratio inlet chaimels. Perpendicular to these chaimels, a 400-pm wide channel is used to deliver catalysts as a slurry to the reaction chaimel and contains two ports to allow cross-flow of the slurry. High maldistribution, pressure drop and large heat losses may occur... 

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