Multi interdigital

Figure 1.20 Periodic concentration profile of a regular multi-lamellar pattern in a rectangular interdigital micro mixer, determined by photometric-type analysis [119].

This system is a chip version of three dimensional micro mixer-tube reactor setups [21]. It comprises a triangular interdigital micro mixer with a focusing zone that thins the multi-lamellae and a subsequent reaction channel that is surrounded... 

Interdigital micro mixers comprise feed channel arrays which lead to an alternating arrangement of feed streams generating multi-lamellae flows [39 2]. If processes have to be carried out with extended residence times (> 1 s) and/or at a temperature level different from the mixing step, tubes have to be attached to the interdigital micro mixers. Their internals comprise millimeter dimensions or below, if necessary. 

Figure 5.29 Special-type multi-purpose micro devices and mixing tee used for investigation of CO2 absorption. Comparison of their reactor performance as a function of the residence time. Micro bubble columns ( ) 1100 pm x 170 pm, (A) 300 pm x 100 pm and (T) 50 pm x 50 pm Interdigital mixer ( ) (40 pm) caterpillar mixer (A) (850 pm ramp) mixing tee (0) (1 mm) [5],...

Fig. 3 Schematic illustration of a microfabricated multi-element array A comprising 32 interdigitated microsensor electrodes, and B comprising 64 independently addressable microdisc voltametric electrodes. Each device shows the large area counter electrode (middle) and the reference electrode as a band around the counter electrode...

Interdigital Multi-laminating Diffusive Mixing (Normal and Focusing)... 

In a vertically multi-laminating variant of the interdigital principle, the two arrays of the multiple sub-streams, belonging to two fluids, are overlaid in such a way that the above-mentioned alternate arrangement results (see Figure 1.75) [34, 67]. This usually requires the reservoirs to be placed in two different layers of the microstructured device. The sub-stream channels typically start in the two different layers and merge in a common layer. 

Figure 1.75 Vertically multi-laminated interdigital feeds.

Considering the width of typical interdigital outlets, which are of the order of several tens of microns, it stands to reason that multi-lamination on its own is a rather slow mixing process, typically needing liquid mixing times of the order of seconds (see Figure 1.76 and, e.g., [34]). 

Mixer 36 [M 36] Unfocused Interdigital Multi-laminating Micro Mixer with Co-flow Injection Scheme (I), Rectangular Mixer ... 

The rectangular mixer is composed of four plates (see Figure 1.78) [20, 39, 124], The second plate contains the complete interdigital feed for one fluid (reservoir + multi-channel feed), the multi-channel feed of the other fluid (without reservoir), the focusing section and the mixing channel. The third plate comprises two rows of multiple holes serving as conduits to the underlying fluid reservoir. Fluid distribution is achieved via these holes. A first plate serves as cover. 

Mixer type Interdigital vertically multi-laminating micro mixer with co-flow injection scheme Feed channel width, depth, length for liquid 2 10 pm, 5 pm, 0.335 mm... 

Mixer type Interdigital horizontally multi-lamina-ting micro mixer (I) Feed channel depth, width 70 pm, 100 pm... 

Mixer 41 [M 41] Interdigital Vertically Multi-laminating Micro Mixer with Counter-flow Injection Scheme, 10-fold Array... 

Mixer type Interdigital vertically multi-laminating micro mixer with counter-flow injection scheme, 10-fold array Number of micro channels for one feed and one element (two versions) 15,18... 

Mixer type Interdigital vertically multi-laminating micro mixer with triangular focusing Number of micro channels 2x15... 

Figure 1.88 U -type frame with hole and opening forming an injection nozzle structure (left) for an interdigital multi-laminating feed of V-like superstructure (right) [34] (by courtesy of AMI).

Mixer type Interdigital multi-laminating micro mixer with flow-re-directed focusing Channel depth 50 pm... 

Figure 1.89 Multi-lamination flow patterns in the rectangular interdigital micro mixer for various flow rates [20] (by courtesy of AlChE).

M 43] [P 39] A regular multi-lamination pattern composed of 30 lamellae is found for a triangular interdigital mixer [20,39], Within the limits of a photographic image no notable deviations are observed. 

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