EP2321538A1

EP2321538A1 - Microfluid device

Info

Publication number: EP2321538A1
Application number: EP09775618A
Authority: EP
Inventors: Andreas Rigler; Michael Vellekoop; Bernhard Lendl
Original assignee: Technische Universitaet Wien
Current assignee: Technische Universitaet Wien
Priority date: 2008-08-28
Filing date: 2009-08-27
Publication date: 2011-05-18
Anticipated expiration: 2029-08-27
Also published as: WO2010022428A1; US20110194995A1; AT507226A1; EP2321538B1; AT507226B1

Abstract

The invention relates to a microfluid device for dispensing a fluid or a fluid mixture, said device comprising a dispensing channel (5), at least one main fluid delivery channel (1, 10) which lies substantially in the plane of the dispensing channel (5) and runs laterally thereto and merges into at least one subsidiary delivery channel (2, 2', 20, 20') that in turn opens into an inlet channel (3, 3', 30, 30') lying above or below the dispensing channel (5), which inlet channel (3, 3', 30, 30') opens into the dispensing channel (5) from above or below via at least one inlet opening (4, 4', 40, 40'), characterized in that the at least one inlet channel (3, 3', 30, 30') has a cross-sectional shape that changes in the longitudinal direction thereof and/or the at least one inlet opening (4, 4', 40, 40') has an opening width that changes in the transverse direction of the dispensing channel (5).

Description

MICRO FLUID DEVICE

The present invention relates to microfluidic devices for dispensing fluids or fluid mixtures.

Well-mixed fluid mixtures are useful in laminar flow systems, e.g. In microfluidic systems, it is difficult to produce since, especially due to lack of turbulence, but also due to short path lengths, no adequate mixing of the supplied fluids, in particular in the case of liquids, can occur. The mixing between different fluid streams flowing in a channel is thus almost exclusively limited to diffusion processes. In addition, in microfluidic applications, cable routing is problematic because of the difficult-to-use third dimension.

One approach to solving these problems is disclosed, for example, in DE 19604289 C2, where in a so-called micromixer two fluid streams are introduced into a mixing chamber on either side of a dividing wall and are thereafter joined together to form an interface therebetween at which diffusion can occur.

The problem of the wiring and the pressure loss in the supply lines and at the junction point of the same in the mixing channel are not addressed in this document.

With regard to the compensation of pressure losses, EP 1 187 671 B1 discloses the introduction of several fluids via inlet channels with correspondingly different tapering cross sections into a mixing chamber of a "micromixer". The taper of the channels extends longitudinally, ie towards the mixing chamber, and the surface of the inlet openings is normal to the longitudinal axis thereof. The channels cross each other without contact and form a common outlet cross section at the mixing chamber. This pressure losses are compensated in the supply lines. The problem that with lateral supply of fluids due to pressure losses in the transverse direction of a mixing channel different amounts of fluid in these are introduced does not occur in this embodiment of a microfluidic device and therefore remains unmentioned.

An example of E. Kauffmann, N.C. Damton, R.H. Austin, C. Blatt and K. Gerwert in "Lifetimes of intermediates in the /? -Heet to α-helical transition of / Mactoglobulin by using a diffusional IR mixer", PNAS 98, 6646-6649 (2001), is presented in Fig. 1 shown schematically. Several fluid streams are introduced via supply channels in a (horizontal in the figure) mixing channel. The feed channels lead from one side of the mixing channel to this and open at the bottom in a row in this one, wherein the cross section of the inlets at the mouth points rectangular, i. is slit-shaped. In this way, a plurality of laminar fluid streams flowing one above the other are generated in the mixing channel, namely one stream per supply channel, between which diffusion occurs in the further course of the mixing channel. Pressure losses are not compensated in this embodiment of a micromixer, so that the supplied amount of fluid varies in the transverse direction of the mixing channel. That is, at the end of the inlet opening farther from the supply line (in the figure: upper end), less fluid inevitably enters the mixing channel than at the closer (lower) end. Since this is the case for each of the supplied fluids, the quality of mixing is poor.

Against this background, the object of the present invention was to provide a microfluidic device, with the above problems in terms of pressure loss and supply line can be solved.

DISCLOSURE OF THE INVENTION

According to the invention, this object is achieved by providing a microfluidic device for dispensing a fluid or fluid mixture, comprising: an output channel, at least one main fluid supply channel, each into at least one secondary supply channel substantially in the plane of the dispensing channel and laterally thereof which in turn merges into an inlet channel located above or below the discharge channel, which opens into the discharge channel from at least one inlet opening from above or below, with the characteristic that the at least one inlet channel has a cross-sectional shape which changes in its longitudinal direction and / or the at least one inlet opening tion has a changing in the transverse direction of the output channel opening width.

Due to this cross-sectional shape of the inlet channel, which changes in its longitudinal direction, and / or the width of the inlet opening (s) in the transverse direction of the outlet channel, varying amounts of fluid can be introduced from it into the outlet channel at different points in the inlet channel. Depending on the shape, locally variable pressure conditions are created, and thus the flow rate and consequently the amount of fluid over the width of the discharge channel are established. For example, the unequal amount of fluid delivered into the dispensing channel due to the pressure difference between the two ends of the inlet channel (s) may be compensated for by widening the inlet channel to the farther end so that there is a larger interface between Inlet and outlet channel for fluid transfer is available. As a result, a uniformly thick fluid layer over the width of the discharge channel can be introduced into the latter. Depending on the application of the device in piping systems, smaller or larger amounts of fluid, e.g. a fluid gradient can be introduced into it, which can be useful not only for mixing purposes, but also, for example, for chemical reactions in this channel.

As for the above designations "up" and "down" and "above" and "below the level of the output channel", it should be noted that these are interchangeable and present due to the variable spatial location of the output channel, even after the microfluidic device has been powered up all for a more detailed explanation of the embodiments shown in the accompanying drawings.

The fluid (s) is / are not specifically limited. These may be any flowable materials or mixtures thereof. Preferably, the invention is used in connection with liquids or liquid / gas mixtures, since the advantages of the invention are particularly effective here. According to the present invention, one or more inlet openings may be provided in the discharge channel for each inlet channel. In the former case, the single inlet opening can be formed from the upper edges of the inlet channel, which is completely open towards the outlet channel, and thus occupies the entire interface between the inlet channel and the outlet channel. This simplifies the manufacture of such microfluidic devices, as will be described later. The shapes of the inlet channels and the respective inlet openings may be the same or different from each other in all embodiments of the invention, which enables a targeted adjustment of the amount of fluid entering the zone across the width of the outlet channel. For example, the inlet channel in the region of the junction, for example, wedge-shaped, taper or widen, while the inlet opening, for example, has a regular rectangular shape. As an alternative or in addition to this, a plurality of openings, for example slot-shaped or circular or even oval, can be provided per single-channel (which sometimes has a changing cross-section), etc.

The manner in which the cross-sectional shape of the at least one inlet channel or the shape of the at least one inlet opening changes is not particularly limited and can be adapted to the respective applications of the device. Preferably, the cross-sectional shape changes linearly, so that the pressure loss over the length of the channel can be well balanced and a uniform distribution of the fluids or fluid mixtures in the transverse direction of the discharge channel is ensured. The resulting fluid flow behavior can be well simulated and optimized by means of computer programs. Because the pressure drop in the channels is exponential, for purely physical considerations, a corresponding exponential change in cross-section would be a potentially even better solution to this problem. Such courses are in practice - at least in the current production techniques - but only at significantly higher cost feasible and therefore currently not preferred. However, with the expected progress of manufacturing processes in the coming years, such cross-sectional shapes may soon be producible with reasonable effort. Preferably, the width of the at least one inlet channel increases in the transverse direction of the dispensing channel, ie at the end there is a larger area available for the fluid transition from the respective inlet channel to the dispensing channel so as to compensate for the pressure drop. The width of the inlet channel can increase both at its upper and lower edges and at only one of them. That is, the inlet duct does not necessarily have to have side walls normal to the plane of the discharge duct, as will be explained later. Also, a variable depth of the channels affects the feed into the dispensing channel, however, a depression of the inlet channels towards the end thereof tends to be an enhancement of the latter due to the larger cross-sectional area

Pressure drop causes, while by decreasing depth (and thus associated smaller cross-sectional area) again the pressure drop can be compensated.

Due to the shape and nature of the cross section of the channels, for example in a round or angular shape, with a rough or smooth surface, by the length of

Channels as well as the shape of the channels - e.g. forming round or square branches - the flow rate of the fluid to the inlet ports can be determined. According to the invention, these agents can be used both instead of and in combination with other, for example, mechanical control agents, e.g. Micropumps, valves, etc. are used.

In other preferred embodiments of the invention, all inlet ports are on the same side of the dispensing channel, i. above or below the same, arranged, as shown schematically in the later discussed in more detail Fig. 3 and 5, where all inlet channels are shown from below the discharge channel in this merging. This arrangement is easier to produce in the manufacture of microfluidic devices.

In preferred embodiments, the main supply channels merge into a plurality of sub-supply and associated intake ports, and also preferably, a plurality of main supply ports are provided. These preferably comprise one or more first main feed channels for introducing a first fluid and one or more a plurality of second main supply channels for introducing a second fluid. This makes it possible to introduce several layers of fluids, also in each case several layers of several fluids, one above the other into the output channel, which improves and accelerates the mixing of two or more fluids, since more than one interface between the fluids for diffusion is available.

Again, especially adapted to the manufacturing conditions of microfluidic applications, the sub-feed and associated multi-fluid inlet channels preferably lead from opposite sides to the dispensing channel because, due to the difficult-to-use third dimension, superposition of the channels in microfluidic devices is hardly possible. For introducing a plurality of layers of a plurality of fluids, preferably a plurality of first secondary supply and inlet channels and a plurality of second secondary supply and inlet channels "comb-shaped" from opposite sides (as will be explained in more detail below) interlock with the dispensing channel or open into it.

The device according to the invention also makes it possible to combine immiscible liquids, so that a solute can diffuse from one phase into the immiscible other phase. In this application, the device does not serve as a mixer but as a micro-extractor.

By the device according to the invention a well controllable mixing by diffusion of two or more layers of miscible fluids is possible. This achieves a reproducible diffusion mixing time behavior whose behavior depends on the properties of the fluids used (inter alia the diffusion coefficient), the flow rate and the layer thicknesses. In this way, a higher mixing quality is achieved compared to the prior art.

In a second aspect, therefore, the invention relates to the use of a just described device for dispensing a plurality of fluids, which are preferably dispensed in the form of layers. The layers can be the same or have different layer thicknesses, since this can be determined over the cross section of the inlet channels and / or the inlet openings. Preferably, the fluids are at least partially mixed during delivery due to diffusion at the interfaces between the layers.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be further described with reference to the accompanying drawings, in which:

1 is a schematic representation of a micromixer according to the prior art described above.

FIG. 2 is a schematic representation of an embodiment of the device according to the invention for introducing a fluid into a dispensing channel via a main feed channel branching into two secondary feed and inlet channels.

Fig. 3 is a longitudinal sectional view of the embodiment of Fig. 2 along the line A-A.

FIG. 4 is a cross-sectional view of three possible embodiments of the apparatus of FIG. 2 taken along line B-B. FIG.

Fig. 5 is a schematic representation of an embodiment of the device according to the invention for introducing two fluids via "comb-shaped" intermeshing inlet channels in an output channel.

FIG. 6 is a cross-sectional view of the embodiment of FIG. 5. FIG.

FIG. 7 is a schematic detail view of various embodiments of an intake passage having a varying cross section. FIG. FIG. 8 is a schematic detail view of various embodiments of intake ports in the intake ports. FIG.

Fig. 9 is a longitudinal sectional view of alternative embodiments of the apparatus of Fig. 2 taken along line A-A.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Fig. 1 shows, as mentioned, a known embodiment of a microfluidic device according to the prior art. In this apparatus, three separate feed channels 2, 2 ', 2 "for liquids in a row in a, here horizontally extending mixing channel 5. In the accompanying, cited publication, a stream of a liquid sample is passed between each buffer stream in the channel, In order to mix these in. The feeding of the three streams takes place from the same side of the mixing channel 5 - in Fig. 1, in

Flow direction of the fluid seen in the mixing channel 5: from the left - on separate supply channels 2, 2 ¹ , 2 ", which must be fed separately due to the impossibility to provide intersecting lines, each such construction is common and simultaneous in the production of microfluidic devices Because of this method of manufacture, the fluid conduits of such microfluidic devices are commonly referred to as conduits, although they are formed by placing a cover plate upon completion of the etch and / or die. In contrast to the term "channel", as used in other fields of technology, for example in construction technology.

Although the field of microfluidics is defined differently in the literature, for the purposes of the present invention, devices are to be understood as having dimensions such that the cross-sectional area of the channels is on the order of a square millimeter or less. One of the problems of such and similar devices solved by the invention is that the amount of fluid entering the mixing channel at both ends of the respective inlet channel is different due to the pressure drop from one end to the other.

FIG. 2 shows a simple embodiment of a microfluidic device according to the invention, which serves mainly to illustrate the principle of the invention. In practice, such a device could not be used as a micromixer but, for example, as a connector between two (micro) lines extending in different spatial directions or as a single channel for fluid (especially liquid) delivery, e.g. in inkjet printers, serve.

In any case, in the device shown in Fig. 2, a fluid can be passed into an output channel 5, as indicated by the arrows. The fluid is via a main supply channel 1, which branches into two secondary supply channels 2, 2 ', which in turn pass into two inlet channels 3, 3' to the output channel 5 and through - in the figures consistently dotted - inlet openings 4, 4 'introduced into this ,

The cross sections of both the inlet channels 3, 3 ¹ and the inlet openings 4, 4 ¹ extend linearly in the mouth region, whereby although the pressure loss increases in the longitudinal direction of the inlet channels, but for an increasingly larger cross-section for the fluid transition into the output channel 5 is available, whereby this pressure loss - depending on the angle of the extension - can be compensated.

Thus, the present invention makes it possible to compensate for the pressure losses occurring in the case of elongated line junctions and the different quantities of fluid delivered in connection therewith, wherein the cross-sectional shapes of the inlet channels or inlet openings can be adapted precisely to the respective conditions. In addition to the cross-sectional shape of the channels in the longitudinal direction, those in the transverse direction, where, for example, round, oval or polygonal cross-sections can be used, are essential, so that not necessarily parallel vertical side walls of the channels must be present. This also affects the pressure ratios in the respective sections of the channels. Two exemplary embodiments of inlet channels with non-parallel sidewalls are shown in FIG. 9 and will be described in more detail later. However, the main and secondary supply channels can also have such non-parallel walls.

According to the present invention, the cross-section of the respective inlet channel, that of the associated inlet opening (s) or even both may change. In all figures, by way of example, a "wedge-shaped", i. linear variation of the cross sections are shown, whose course is also the same at the inlet channel and opening, as indicated by the parallelism of the lines. In practice, however, arbitrary combinations of different cross-sectional shapes can be used as long as the flow behavior of the fluid or fluids in the device according to the invention is thereby advantageously influenced. In addition to linear changes, any other shapes, with curves, waves, corners, edges, teeth and the like, are possible, all of which are intended to be within the scope of the present invention.

As already mentioned, in the practice of microfluidic devices, there is often no explicit "inlet opening" into the channel 5. Rather, the inlet channels in the mouth region are simply open towards the channel 5, so to speak a single, the entire upper side of the channel 3 in the mouth region engaging opening 4 is present.

By suitable construction, especially with somewhat larger dimensions near the limeter area, however, several inlet openings can also be provided per inlet channel, which in turn can have any desired shapes. For example, a sequence of slit or circular openings-in the longitudinal and / or transverse direction-is thinkable and feasible, through which the openings in the inlet channel are admitted. led fluid enters the dispense channel at multiple, discrete locations.

Also possible is a combination of an inlet channel with linear, e.g. wedge-shaped or conical, or curved tapered cross-section and extending in the longitudinal direction of the inlet channel, slot-shaped inlet opening with a regular rectangular cross-section. The tapering cross-section of the channel then equalizes the pressure drop toward the farther end of the opening so that in turn equal amounts of fluid can enter the discharge channel at both ends of the opening.

In addition to the changing cross-sectional shape in the mouth region, the cross-section of the inlet or inlet channel upstream of the junction can also change in order to influence pressure differences in the supply lines. This can be done in known manner, i. As in the above-mentioned EP 118.767 B1, by tapering design of the channels 1 and / or 2 or 2 'to the output channel 5 through out. In this way, it can be ensured that the same amount of fluid is delivered to all inlet channels in the case of a main feed channel branching into a plurality of secondary feed and corresponding inlet channels, which results in equal layer thicknesses of the fluid in the output channel. On the other hand, it is also possible to selectively deliver different amounts and thus to produce different layer thicknesses of several layers of the same fluid, if this is advantageous for the respective application. How strong the pressure drop within the supply or inlet channels is, of course, depends on their length and thus also on the distance of the junctions of the inlet channels in the output channel. The cross-sectional changes must be adjusted accordingly in each individual case.

Fig. 3 shows a schematic longitudinal sectional view of the embodiment of Fig. 2 along the line AA, from which it appears that both inlet channels 3 and 3 'from the same side, namely from below, open into the outlet channel 5. This is contrary to the manufacturing technology of microfluidic devices. In addition, the side walls of the inlet channels 3 and 3 'are formed in parallel. Alternatives will be described later in connection with FIG. Fig. 4 shows schematically three possible cross-sectional views of the embodiment of Fig. 2 along the line BB. It can be seen that the cross-section of the inlet channel 3 ¹ can not only - as shown in FIG. 2 - increase in the plane of the discharge channel 5, so that it widened in the flow direction of the fluid, but can also increase or decrease perpendicular thereto , In Fig. 4a, the inlet channel 3 'deepens over the width of the output channel 5, and in Fig. 4b decreases its depth. The latter case causes an increase in the pressure towards the end of the inlet channel 3 ', whereby the pressure drop in the longitudinal direction of the inlet channel 3' can be compensated - or even an increasingly larger amount of fluid can be introduced into the outlet channel 5 in a targeted manner. On the other hand, in the case of a depression of the inlet channel, as shown in FIG. 4 a, the pressure drop is increased by the enlargement of the channel cross section, so that specifically smaller amounts of fluid can be introduced into the outlet channel 5 at the end of the inlet channel 3 '. Fig. 4c shows an embodiment with a constant depth of the inlet channel 3 ', which represents a presently preferred embodiment due to the ease of manufacture.

Fig. 5 shows an embodiment of the device according to the invention, in which two fluids are supplied from opposite sides of the discharge channel 5 to this. A first fluid is analogous to the embodiment of Figure 2 via a main supply channel ^{1, which} branches into two secondary supply channels 2 and 2 ¹ and in the sequence in two inlet channels 3 and 3 ¹ , introduced. a second fluid via the analog components 10, 20/20 'and 30/30'. The cross-sectional shapes that change in the mouth region can be combined again as desired. For clarity, wedge-shaped cross sections are again shown. For reasons of space savings in the manufacture of such microfluidic devices would in practice be the wedge-shaped extensions of the inlet channel pairs 3/30 and 3730 'facing each other running, ie the channels 30 and 30' in the drawing would not right above, but after expand on the top left. Furthermore, it will be appreciated that in this embodiment, no explicit inlet openings are provided, since the inlet channels 3/3 'and 30/30' are open towards the top of the dispensing channel 5, so that in each case the entire, formed by the upper edges of the inlet channels with the output channel 5 represents the respective inlet opening.

The total of four secondary supply channels 2, 2 ', 20, 20' with their inlet channels 3, 3 \ 30 ', 30 engage here "comb-shaped" with each other, which means that they open alternately from opposite sides in the output channel 5. In this way, two layers of the two fluids are alternately introduced into the output channel, whereby a total of three interfaces for the diffusion between the two fluids are available. With an even higher number of branches, this effect can be further enhanced. This significantly speeds up mass transfer between the fluids, such that such devices are excellent micromixers or, in the case of immiscible liquids, micro-extractors.

One application is about the production of micro-fluid mixtures with a high mixing quality. For the development of new drugs, the optical detection of chemical properties and reactions is becoming increasingly important. To obtain satisfactory results, the rapid and high quality mixing of fluids is particularly important here.

For the preparation of such fluid mixtures, it makes sense to use more than two layers of fluids in order to minimize the diffusion paths. At the same time, any flows occurring in a direction other than in the direction of flow must be distributed as homogeneously as possible over the cross section of the discharge channel.

In order to achieve this, a profile of the device according to the invention with an aspect ratio of 1:10 for the inlet channels and / or the inlet opening is used for many-in particular aqueous-fluids. With an aspect ratio (width difference: length) of 1:10, an expansion of the (eg wedge-shaped) Channel of, for example, 10.0 microns at the beginning of the inlet channel to 20.0 microns at its end over a length of the inlet channel of 100.0 microns understood. As a result, a readily reproducible time behavior of the mixing is achieved by diffusion of two or more fluids, the quality of the mixing also being decisively influenced by the mixing behavior (diffusion coefficients) of the fluids and the flow velocities.

Accordingly, the embodiment shown in FIG. 5, like the previously discussed embodiment of FIGS. 2 to 4, eliminates the problem of pressure differences in the inlet region into the outlet channel. At the same time, however, the supply of two different fluids from opposite sides is a new and advantageous solution to the problem of routing in microfluidic devices. Because of the difficult-to-use third dimension, intersecting lines are virtually impossible to manufacture, so that several supply channels - and not merely inlet channels - were required for alternately supplying a plurality of streams of the same fluid, as explained in connection with FIG.

FIG. 6 shows a longitudinal sectional view of the embodiment from FIG. 5 along the line AA from FIG. 5. From this it can be seen that all the inlet channels 3, 3 ", 30 and 30 'enter the outlet channel 5 from the same side, again from below This again counteracts the fabrication technique of microfluidic devices where the channels are etched into an existing substrate, cut, etc. Since the line AA in Fig. 5 does not extend at half the width of the output channel 5, the thickness of the inlet channel pairs is 3 Again, the walls of the inlet ducts need not necessarily be perpendicular, ie normal to the plane of the discharge duct, as shown in FIG By the inlet channels becoming wider or narrower towards the bottom, the quantity of fluid passing from the respective inlet channel into the outlet channel and thus the layer thickness can likewise be increased the fluid can be controlled at this point of the output channel. Such a change in cross section of the inlet channels is also within the scope of the present invention. 7 shows by way of example schematically different embodiments of the cross-sectional changes of the inlet channels in the plane of the discharge channel. As can be clearly seen, widening and narrowing shapes across the width of the dispensing channel 5 as well as any combinations thereof, including combinations of a straight and an oblique or curved longitudinal wall of the inlet channel 3, are possible. Widening shapes are preferred in order to compensate for the smaller amount of fluid due to the pressure drop over the length of the inlet channel 3, which at its end passes into the discharge channel 5. Such and similar, but also any other cross-sectional changes are also possible for the depth of the inlet channels, as already explained above. This means that even the depth of an inlet channel need not necessarily increase or decrease linearly in order to ensure optimum, desired flow conditions for the fluid (s) in the device according to the invention.

Fig. 8 shows various embodiments of the shapes of the inlet openings, wherein the sake of clarity, the inlet channels are plotted without changing cross-section. In fact, however, any combination of the embodiments shown in FIGS. 7 and 8 and any other embodiments are possible since the invention is by no means limited to the embodiments shown or discussed herein.

As already mentioned, FIG. 9 shows alternative embodiments of the inlet channels 3 and 3 'from FIG. 3 with non-parallel side walls, which can also be combined with any of the previously described channel cross-section changes and aperture shapes. Channel 3 is here exemplarily with oval cross-section, i. with bulged side walls, represented; Channel 3 ', however, with a downwardly tapered cross-section. As already mentioned, additional measures may also be taken on the channel sidewalls, such as e.g. Grooves, grooves, grooves, corrugations and the like in order to influence and optimize the flow behavior of the fluids in the channels.

In summary, it should be noted that the present invention is a valuable resource. Advances in the state of the art in the field of microfluidics, since it solves existing problems in a relatively simple manner by providing devices that are inexpensive and can be produced by known methods. Accordingly, there is no doubt about the industrial applicability of the invention.

Claims

A microfluidic device for dispensing a fluid or fluid mixture, comprising an output channel (5), at least one main fluid supply channel (1, 10), each in at least one substantially in the plane of the output channel (5) lying and laterally leading to this side supply channel (2, 2 ', 20, 20'), which in turn merges into an inlet channel (3, 3 ', 30, 30') lying above or below the dispensing channel (5), which via at least one inlet opening (4, 4 \ 40, 40 ') opens from above or below into the dispensing channel (5), characterized in that the at least one inlet channel (3, 3 \ 30, 30') has a cross-sectional shape which changes in its longitudinal direction and / or the at least one Inlet opening (4, 4 ', 40, 40') has a transverse width of the discharge channel (5) changing opening width.

2. Apparatus according to claim 1, characterized in that per inlet channel (3, 3 \ 30, 30 ') an inlet opening (4, 4', 40, 40 ') is provided.

3. A device according to claim 2, characterized in that the inlet opening (4, 4 ', 40, 40') of the upper edges of the up to the output channel (5) towards fully open inlet channel (3, 3 \ 30, 30 ') is formed.

4. Apparatus according to claim 1, characterized in that per inlet channel (3, 3 ", 30, 30 ') a plurality of inlet openings (4, 4', 40, 40 ') are provided.

5. Apparatus according to claim 1 to 4, characterized in that the width of the at least one inlet channel (3, 3 ', 30, 30') increases.

6. Apparatus according to claim 1 to 5, characterized in that the depth of the at least one inlet channel (3, 3 ', 30, 30') increases.

7. Apparatus according to claim 1 to 6, characterized in that all the inlet openings (4, 4 ', 40, 40') on the same side, ie above or below, the Output channels (5) are arranged.

8. Apparatus according to claim 1 to 7, characterized in that the at least one main supply channel (1, 10) via a plurality of secondary supply channels (2, 2 ', 20, 20') into a plurality of inlet channels (3, 3 ', 30, 30') passes.

9. Apparatus according to claim 1 to 8, characterized in that a plurality of main supply channels (1, 10) are provided, the at least one first main supply channel (1) for introducing a first fluid and at least a second Hauptzu- supply channel (10) for introducing a second Include fluids.

10. The device according to claim 9, characterized in that the at least one first main supply channel (1) via at least a first secondary supply channel (2, 2 ') in at least a first inlet channel (3, 3') merges and the at least second main supply channel (10). via at least a first secondary supply channel (20, 20 ') merges into at least one second inlet channel (30, 30'), wherein the first and second secondary supply channels lead from opposite sides to the outlet channel (5).

11. The device according to claim 10, characterized in that a plurality of first secondary supply channels (2, 2 ") and inlet channels (3, 3") and a plurality of second secondary supply channels (20, 20 ') and inlet channels (30, 30') are provided, the from opposite sides comb-like interlocking to the output channel (5) lead or open into this.