Microcolumn array

Dispersions at micron scale are usually made by merging gas and liquid streams in a mixing element and subsequent decay of the gas stream to a dispersion [251-262]. Mixing elements often have simple shapes such as a mixing tee (dual-feed gas-liquid) or triple-feed (liquid-gas-liquid) arrangements. The dispersion is passed either in a microchannel (or many of these) or in a larger environment such as a chamber, which, for example, provides volume to fill in porous materials such as catalyst particle beds, foams or artificial structures (microcolumn array). The mechanisms for bubble formation have not been investigated for all of the devices... 

Chen, Y. and Vertes, A., Adjustable fragmentation in laser desorption/ionization from laser-induced silicon microcolumn arrays. Anal. Chem., 78, 5835-5844 (2006). 

Studies were also performed with an artificial fixed bed composed of an array of microstructured columns made by a plasma etch process. These columns were made porous to increase the surface area to 100 m2, which is not far from the porosity of catalyst particles in fixed beds, and then coated with a catalyst [278]. The performance of such catalytic microcolumns was compared with that of a catalytic fixed bed reactor. When normalized to the metal content, the reaction rates of the columnar and the particle-containing reactor are similar with 6.5 x 10 5 and 4.5 x 10-5 mol/(minm2), respectively. 

Furuta N., Brushwyler K. R. and Hieftje G. M. (1989) Flow-injection analysis utilizing a spectrally segmented photodiode array ICP emission spectrometer I. Microcolumn preconcentration for the determination of molybdenum, Spectrochim Acta, Part B 44 (1989) 349-358. 

The diamond growth can also be patterned to produce microelectrode array structures [18,19]. Several possible microstructures are possible, such as microbands, microdiscs, and microcolumns. Micropyramids are another microstructure that can be produced, and an image of such an array is shown in Fig. 5. The SEM image reveals a monolithic diamond-tip array. The tips are ca. 2 pm in base diameter and are equally positioned over the surface with a spacing of ca. 5 pm. 

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