Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K51/00—Other details not peculiar to particular types of valves or cut-off apparatus
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/0093—Microreactors, e.g. miniaturised or microfabricated reactors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/30—Micromixers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
  • B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
  • B01L3/502—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures
  • B01L3/5027—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip
  • B01L3/502707—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip characterised by the manufacture of the container or its components
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00781—Aspects relating to microreactors
  • B01J2219/00783—Laminate assemblies, i.e. the reactor comprising a stack of plates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00781—Aspects relating to microreactors
  • B01J2219/00819—Materials of construction
  • B01J2219/00822—Metal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00781—Aspects relating to microreactors
  • B01J2219/00851—Additional features
  • B01J2219/00858—Aspects relating to the size of the reactor
  • B01J2219/0086—Dimensions of the flow channels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2200/00—Solutions for specific problems relating to chemical or physical laboratory apparatus
  • B01L2200/12—Specific details about manufacturing devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/06—Auxiliary integrated devices, integrated components
  • B01L2300/0681—Filter
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0861—Configuration of multiple channels and/or chambers in a single devices
  • B01L2300/0874—Three dimensional network
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0887—Laminated structure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2400/00—Moving or stopping fluids
  • B01L2400/08—Regulating or influencing the flow resistance
  • B01L2400/084—Passive control of flow resistance
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
  • Y10T137/0324—With control of flow by a condition or characteristic of a fluid
  • Y10T137/0329—Mixing of plural fluids of diverse characteristics or conditions
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
  • Y10T137/0324—With control of flow by a condition or characteristic of a fluid
  • Y10T137/0329—Mixing of plural fluids of diverse characteristics or conditions
  • Y10T137/0352—Controlled by pressure
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
  • Y10T137/0402—Cleaning, repairing, or assembling
  • Y10T137/0491—Valve or valve element assembling, disassembling, or replacing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/206—Flow affected by fluid contact, energy field or coanda effect [e.g., pure fluid device or system]
  • Y10T137/2224—Structure of body of device

Definitions

• the invention relates to the technical field of microfluidic channel structures and the production of microfluidic channel structures, which proves to be particularly problematic in fluidic channels with a high aspect ratio.
• Microfluidic systems are currently used in many technical fields. Microfluidic systems are used in particular in the field of modern analysis methods. Modern analysis methods are characterized, among other things, by the fact that only small amounts of sample are used for the analysis, so that the analysis systems prove to be active ingredient-friendly and environmentally friendly. However, often only small amounts of sample are available for analysis, so that sample handling is often required in the range of a few microliters. Furthermore, it shows that it is e.g. B. in the medical or diagnostic field is an effort to minimize sample amounts as much as possible. The patient should thus take complex body fluids, such. B. blood collection, are spared.
• Microstructures in which production proves to be particularly difficult are, in particular, microfluidic systems with a high aspect ratio, which have recently been used with increasing frequency.
• microfluidic channels with a high aspect ratio are distinguished by the fact that despite a small width in the range of only a few micrometers, they have a great depth, which is aimed at in a range of a few centimeters.
• An application example for channels with a high aspect ratio are e.g. B. filtering processes in which there is a filter material within a channel. With a sample placed in the channel, z. B. due to gravity, a filtrate in the lower region of the channel, which can be collected there.
• the channel is characterized by sufficient depth so that a filtering process can run completely.
• the channel should only have a small width in order to ensure that the sample volume is minimized.
• An example of such filtering processes is the area of plasma extraction from blood. The blood cells in the upper area of the channel are retained in the filter material, while the plasma in the lower area of the channel can be obtained as a filtrate.
• particulate material such as, for example, B. sample components bound to particles, is removed from the remaining sample components.
• microfluidic channel systems with a high aspect ratio Another area of application for microfluidic channel systems with a high aspect ratio is in the field of producing liquid mixtures.
• a variety of possible applications are also conceivable here, which require an effective mixing of small sample volumes.
• the use of microstructures with a high aspect ratio proves.
• microfluidic channel systems are essential. Examples of this are e.g. B. microdialysis systems, the z. B. for glucose determination in diabetics.
• the prior art therefore discloses many possibilities for producing microfluidic systems with a high aspect ratio, as well as possibilities for their use.
• the US Pat. No. 6,251,248 exemplifies a microstructure that is formed due to a controlled swelling of a polymeric material. Using an electrolytic solution and an ionomeric polymer, the system can be shaped in a controlled manner due to a controlled current flow.
• documents US 6,068,684 and US 6,051,866 disclose microstructures which are produced by means of etching processes and radiation. Here, different variants of etching and radiation are possible, such as z. B. of structured reservations from the field of photoresist layers are known.
• the document WO 99/36941 uses u. a. the pattern of metal.
• the processes prove to be complex, so that considerable costs are incurred not only because of the materials required for the processes, but also because of the manufacturing processes themselves.
• the channel structures provided for this - as already described - have a low aspect ratio for a given cross-sectional area.
• B. the mixing of different samples is incomplete and slowed down.
• the choice of material depending on the manufacturing process also limits the use of the respective microstructure.
• the channel walls of a microstructure which is produced monolithically by means of stereolithography, have high surface roughness, so that microscopic observation of the microfluidic structure is not possible.
• the invention is based on the object of providing a microfluidic system with a high aspect ratio and a method for producing such a system which overcomes the disadvantages of the prior art described.
• the invention includes a channel system for microfluidic flows with a large aspect ratio.
• the channel system has a first and a second body, which are connected to one another in such a way that a first surface of the first body and a second surface of the second body are at a defined distance from one another and thereby have a first fluidic channel between the first and the second Surfaces is formed.
• the channel system includes a third body, which is also connected to said two bodies or a further body in such a way that a third surface of the third body, each with a further surface of two bodies, is at a defined distance from one another and thereby a second fluid Channel between the third surface and the other two Surfaces is formed.
• the resulting channel system is characterized in that the first channel crosses the second channel, so that the channel system contains at least three fluid connections through which a fluid can flow in and / or out.
• the duct system according to the invention is characterized by a simple and inexpensive manufacturing process.
• the materials of the body are freely selectable and can be adapted to the respective intended field of application.
• the bodies preferably have a surface texture with a low roughness in relation to the defined distance between the surfaces, which is also referred to below as the channel width.
• the surface quality is furthermore advantageously characterized by the fact that it is inert towards the fluids intended for use.
• the manufacturing method according to the invention makes it possible to freely choose the depth of the channel through the dimensions of the body surfaces and the width of the channel by choosing the defined distance between two surfaces.
• the aspect ratio can hereby be selected to be high, namely aspect ratios of> 10 or even> 100 can be achieved for the device according to the invention.
• microfluidic channel structures according to the invention are further distinguished by the fact that an exactly defined structure can be selected which enables two channels to be crossed without a dead volume being formed at the crossing points.
• fluid connection is defined in the sense of the invention by the flow direction of the fluid, so that depending on the flow direction, a fluid connection can also be referred to as inflow or outflow.
• a channel system according to the invention can of course have several flow directions, which is also referred to below as the flow direction. The direction of flow changes depending on the geometric orientation of the respective channel.
• the duct system according to the invention is designed such that it has at least three fluidic connections which are fluidly connected to one another. In principle, however, the channel system can contain a large number of channels, as well as inflows and outflows, the channels at least partially crossing.
• the width of the channels is, as already described, defined by the distance between the surfaces of the respective bodies and can be almost small to z. B.
• any depth is freely selectable for the channel system, so that a depth of several centimeters can be reached without problems can be.
• the channel system according to the invention can consequently easily achieve aspect ratios> 3 in comparison to the prior art.
• the formation of intersecting channels in the form of a T, Y or cross piece may be mentioned here.
• the channel system according to the invention shows that a direct mixing of fluids is possible without any problems.
• the use of intersecting channels with a high aspect ratio significantly improves the mixing of the fluids, since, in contrast to the channel system with a low aspect ratio, the time until complete mixing is reduced for a given cross-sectional area. This can be explained by an enlargement of the “contact areas” of the adjacent channels and is explained in more detail below with reference to the figures.
• Advantageous embodiments of the channel system preferably have the above-mentioned intersecting structures.
• the channel system contains three bodies, two of which are already connected to form a microfluidic channel, z. B. the third body each connected to a surface of the first and second bodies so that the intersecting channels essentially form a T-piece or a Y-piece. If the channel system further includes a fourth body, so that the third body is connected to a surface of the first and a surface of the fourth body, and a further surface of the fourth body is connected to a further surface of the second body, the intersecting channels form essentially a cross piece.
• the shape of the channel structure can be freely selected, so that many options are conceivable. Depending on the arrangement and the shape of the bodies, any non-rigid shape can be formed by intersecting channels.
• the distances between the surfaces of the bodies are ⁇ 1 mm, preferably the side lengths of the interconnected surfaces that are substantially perpendicular to the flow direction are one length of> 1 cm so that a corresponding depth of the channel is formed through this side length. It shows up in some areas of application, such as. B. Filtration processes that the side lengths of the body, which determine the depth of the channel, can also be aligned parallel to the flow direction. The fluid then flows along the channel depth, which z. B. in separation processes that take advantage of gravity can prove advantageous.
• an advantageous embodiment of the channel system is characterized in that the side lengths of the surface, which determine the depth of the channel, are many times larger than the defined distance between the surfaces, so that there is a large aspect ratio.
• the aspect ratio of at least one channel in the channel system is preferably> 3.
• the surfaces that delimit the channel are planar, so that the channel formed between the surfaces is as flat as possible. This means that the roughness of the surfaces is chosen to be as small as possible in relation to the intended channel width.
• the channel system has connecting elements which represent elements which are independent of the bodies to be connected and by which the respective bodies are connected to one another. These connecting elements preferably have a constant thickness, so that the channel width that results from this is also constant.
• such connecting elements are formed from a film which, for. B. has a thickness of ⁇ 100 microns. It is preferred according to the invention that the connecting elements are only used as spacers during the manufacturing process in order to guarantee a uniform distance between the surfaces of the bodies and are removed again from the channel system after the bodies have been connected.
• z. B. the possibility of connecting the bodies together by an adhesive.
• the adhesive can serve both as a connecting element itself and, with even application, allow a defined distance between the surfaces. However, it is also conceivable that the adhesive serves to connect the connecting elements to the respective surfaces.
• the adhesive is preferably designed such that this results in a fluidic seal of the duct system, the adhesive being inert towards the fluids intended for use.
• the surfaces of the bodies which each delimit a channel, preferably have essentially the same area dimension, so that the bodies can optionally be adapted to the desired channel structure. Further preferred embodiments result from the selected field of application of the microfluidic system. For example, if a separation medium is present in at least one channel, z. B. one- separations of samples and reaction mixtures and, on the other hand, filtrations are carried out. Do you make z. B. in filtration processes to use gravity to obtain a filtrate, the fluid flows in such applications along the channel depth. In this area of the channel system, the side length of the bodies that determine the depth of this channel then runs parallel to the direction of flow.
• the integration of additional components in the duct system continues to be advantageous in the field of optics.
• the integration of micro-optical systems such. B. microlenses, reflective surfaces such as mirrors and / or photodiodes, e.g. B. the optical detection of analytes in microchannels.
• the optical path length in the case of absorption and fluorescence detection can be increased that there is an increase in sensitivity.
• Such integrations of components allow z. B. a portable use of the instrument, since the adjustment accuracy is reduced.
• spectrometric measurement in microchannels by e.g. B. simultaneous excitation and detection of analytes in the channel system.
• z. B. detection of analytes immobilized on channel walls is conceivable, to name just a few examples.
• valve function can be realized in microchannels.
• the control of flows through valve functions in microfluidic structures proves to be advantageous, for example, when channel segments are to be temporarily delimited in order to e.g. B. fluidically isolate injection solutions and reaction mixtures.
• z. B Properties of the surface, such as transparency or conductivity, as well as properties of the materials of the body itself, such as electrical and thermal conductivity, were addressed. Is there a boundary wall of a microchannel z. B. from magnetizable properties, there is retention of the particles on the channel wall after loading the microchannel with magnetic particles.
• Such an application is e.g. B. in assays, which magnetic particles as exchangeable Ober- surface and carrier of reagents, such as. B. use antibodies, useful. In this way, specifically bound sample components can be eluted with a suitable washing solution by means of suitable washing processes.
• the channel system has the ability to change the temperature of a body in a targeted manner, it is possible, for example, to induce a liquid movement in the direction of a cooler change element by locally heating a change element.
• the dependence of the surface tension on the temperature is used for a thermally induced movement.
• the invention furthermore relates to a method for producing microfluidic channel systems with a large aspect ratio, preferably with an aspect ratio of greater than 10.
• the method includes connecting a first surface of a first body to a second surface of a second body in such a way that a there is a defined distance between the first and the second surface and a fluid channel is formed between these surfaces. This process is repeated with a third surface of a third body, which is connected to a further surface of the two bodies or a further body.
• the surfaces of the bodies are also connected to one another again in such a way that there is a defined distance between the surfaces of the bodies, so that a fluidic channel system is formed from at least two intersecting channels, and the channels intersect in such a way that the channel system contains at least three fluidic connections through which a fluid can flow in or out.
• Preferred embodiments of the method result as described.
• Figure 1 Production of a microfluidic channel structure with spacers
• Figure 2 Microfluidic channel structure in the form of a T-piece with a
• FIG. 3 Microfluidic channel structure in the form of a Y-piece
• Figure 4 Microfluidic channel structure with two intersecting channels
• Figure 5 Microfluidic channel structure with an array of microfluidic channels
• Figure la to e shows an example of the production of a microfluidic channel system with 2 or more channels.
• 3 bodies (1-3) are combined to form a channel system.
• quantitative results For this purpose, the surface of the body (1) is first connected to a surface of the body (2) via connecting elements (4). Because of the connecting elements, it is possible to define the distance between the two surfaces of the bodies 1 and 2 by the thickness of the connecting elements (4).
• the connecting elements (4) are connected to the respective surfaces by means of an adhesive, a fluidic seal being achieved at the same time by the adhesive.
• the bodies 1 and 2 thus form a fluidic channel between them, which is delimited at its upper and lower ends by the connecting elements (4).
• the depth of the channel is defined by the edge length (5) of the body, which is perpendicular to the direction of flow (6).
• the drawing can be used to make it clear that, depending on the choice, the body 1 to 3 and the connecting elements (4) can form a high aspect ratio of a channel. It is only important to ensure that the connection to the connecting elements and bodies, for. B. by a resin is such that the channel ends so connected are not permeable to a fluid.
• the adhesive used should furthermore advantageously seal reliably even when small amounts are used, so that the channel width is not increased by the additional application of the adhesive. It is also important to ensure that the adhesive is evenly distributed.
• a third body (3) is connected to a further surface of the body 1 and 2 via two further connecting elements (4).
• the channel structure thus formed forms a T-piece in which a first channel, formed by the bodies (1 and 2), crosses a second channel, formed by the bodies 1, 2 and 3.
• Figure 1 a illustrates the simplicity of the method by way of example.
• FIG. 1b A further simplification for the production of the microfluidic structure shown is shown by way of example in FIG. 1b.
• several channel structures in T-shape are produced at the same time.
• two almost equally large bodies (10 and 11) are used.
• the body (10) is cut in such a way that several bodies of a desired size result from this.
• the cut lines (12a - d) of the body (10) form the channels in the later channel system.
• the individual bodies are connected to each other at the upper and lower areas of the cutting lines over a defined distance. This can, as already shown in Figure la, done by connecting elements or z. B. can be realized directly using an adhesive.
• the bodies can also be connected to one another by means of an adhesive or a foam which is applied to the surface (14), so that there is no adhesive in the interior of the channel.
• the upper or lower area of the interface is not inside the channel formed, but is part of the surfaces (14) of the body (10).
• the cut body (10 '), which is again connected to one another, thus represents a channel structure with 4 parallel channels of identical design.
• the second body (11) is then connected to the body (10'), so that an additional channel (12e ) in which the channels (12a - 12d) open.
• the joined bodies (10 'and 11) are cut again, so that four microfluidic structures (13a-13d), the channels of which form a T-piece, result.
• Figure lc - le shows an example of some other possibilities through which a connection of bodies can be realized and simplified. It is important to ensure that the connection is designed in such a way that the channel systems are fluidly sealed and a defined distance between the individual surfaces of the bodies is guaranteed.
• two bodies are positioned relative to each other due to a strong magnetic field. If the magnetic field strength of a magnetic base (8) is chosen to be sufficiently large, then an exact positioning of the bodies (1 and 2) on the magnetic base (8) can be ensured.
• One advantage of such a connection possibility is that the assembly of a microfluidic system can be carried out quickly and variably. Furthermore, no connecting elements are necessary, each of which defines a defined channel width of the microstructure.
• FIG. 1d A further possibility of connecting bodies to one another and positioning them relative to one another is shown in FIG. 1d.
• the bodies (1 and 2) are positioned relative to one another by means of a template (7).
• a template (7) serves as a connecting element in the microfluidic system and is integrated into this.
• the advantages of using a template is that it automates the manufacturing process of microfluidic systems for each channel width. It is also conceivable to provide templates specifically for different channel widths, so that the manufacture of the systems is simplified.
• FIG. 2 shows a top and front view of a microfluidic system, in which the channels form a T-shape and a lining material is provided for separating a sample in the channel system.
• FIG. 2a shows the top view of a channel structure which is formed by the bodies (1-3).
• the fluid is introduced through the channel (17) between the bodies (1 and 2) and from there is transferred into the crossing channel (18), which is delimited by the bodies (1, 2 and 3).
• a filter medium (19) is located within the upper region of the channel (18).
• the depth of the channel (17) is significantly less than that of the adjacent channel (18). This can e.g. B.
• edge length (21) of the body (1 and 2) is selected to be correspondingly short and the body (1 and 2) are connected to a further body (22).
• no channel is lined between the bodies (1 and 2) and the body (22), but rather a direct connection of the elements takes place.
• edge lengths (21) of the bodies (1 and 2) it is also possible for the edge lengths (21) of the bodies (1 and 2) to be selected to be equal to the edge length (23) of the body (3).
• the channel depth between the body (1 and 2) must then be regulated accordingly using a connecting element.
• the connecting element then has a corresponding height, which additively corresponds to the edge length (21) of the edge length (23) of the body (3).
• the connecting element then extends over the entire length of the channel of the channel (17) formed by the body (1 and 2).
• a filter medium is integrated in the channel (18) in the upper area. Due to the different aspect ratios of the two channels, a fluid flows out of the channel (17) in the upper region of the channel (18) in which the feed medium (19) is located. The fluid is passed through the feed medium (19) and is separated there. A sufficiently high aspect ratio ensures that there is sufficient separation of the fluid by the feed medium.
• the feeding takes place e.g. B. due to gravity, the feed rate settling in the lower end of the channel. With the help of such a channel structure it is consequently possible to filter even small amounts of fluid and so z. B.
• the channel width is chosen to be so small that only certain fluid-containing media provided as the feed rate can pass through the channel.
• the adaptation of the channel width to certain fluid-resistant oils is only an expensive example of application, which is particularly easy to implement, in particular by the system according to the invention, in comparison with the prior art, since a constant and defined channel width over the entire th course of the channel depth can be guaranteed.
• FIG. 3 shows a microfluidic channel system, the channels being connected to one another in the form of a Y-piece.
• a fluid is introduced via the channel (100).
• the fluid flow is thickened by crossing the channels (102 and 103).
• the fluid can be separated by the choice of the channel width.
• the width of the channel (102) is chosen to be smaller than that of the channel (103).
• such a channel structure can be used to obtain plasma from primary blood or to remove sample components bound to particles.
• the branching of the microchannel separates the predominant part of an erythrocyte from the blood plasma.
• the reduced channel width of the channel (102) separates the erythrocytes from the blood plasma at the branching of the channel (100), so that blood enriched with erythrocytes flows along the channel (103) while the blood plasma is obtained from the channel (102) can be.
• the channel width of the channel (102) is preferably selected such that it corresponds to a few erythrocyte diameters.
• the high aspect ratio of the channel structure allows a high volume throughput for plasma separation, although the channel width is minimized. This means that the feed capacity in the illustrated example can be significantly improved by increasing the channel depth.
• FIG. 3a shows that, due to the freely selectable aspect ratio, sample preparation can be carried out easily, without using feed material. Further application examples are shown in FIGS. 3b and 3c.
• two different fluids (107 and 108) are introduced through the channels (100), the fluids being mixed in the channel (104).
• the mixing of the fluids shows that with a large channel depth, two different fluids can be mixed quickly and completely. This is due to the fact that the contact of the two fluids can take place along the entire channel depth. The larger this is chosen, the larger the contact area of the fluids which are intended for mixing. In order to be able to achieve the same fluid flow in the prior art with a lower aspect ratio, the channels would have to be chosen wider due to a smaller depth.
• a comparison of the systems clearly indicates that the mixing of two fluids with a large channel width occurs only improperly in the same period.
• PrinzipieU finds the mixture of two fluids, for example - as already mentioned - for the production of dilution series, concentration gradients, elution gradients or z.
• B. enzyme substrate mixtures instead, to name just a few examples.
• the fluid flow runs analogously to FIG. 3a.
• the channels (102) and (103) are each selected with identical dimensions.
• the channel structure is used to evenly distribute the fluid onto the two channels and to guide them to a test field (110).
• Such an application example is e.g. B. needed to be able to perform several test procedures on a sample at the same time.
• a variety of channel structures can be configured in the form of a network, which simplify sample handling.
• the system according to the invention enables 3-dimensional branching of channels with a high as well as a lower aspect ratio. This is particularly advantageous when highly complex sewer networks have to be integrated on small footprints.
• GenereU shows that for a given width of a microchannel, increasing the aspect ratio reduces the time for complete homogenization or separation of two or more streams.
• FIGS. 4a and 4b to 4c contrast the microfluidic channel structure according to the invention with a high aspect ratio to a microfluidic channel structure with a low aspect ratio and shows the advantages according to the invention using a chromatographic tremor method.
• a sample (32) is introduced into a microfluidic channel structure.
• the channel structure is embodied as a cross piece. If the sample (32) gets into the channel structure, there is a separation of the sample components, which have a different measuring speed depending on the separating medium in the respective channel (30 and 31). This is illustrated in FIG. 4 by the identification of the various sample components (32), (32 ') and (32 ").
• the sample components are transferred into the channel (31)
• the sample stock is measured and identified by means of a detector. In general, it can be seen in separation processes that the selectivity of two sample components is of great importance in the analysis.
• the resulting increase in the number of samples (32) and (32 ') in the channel (31) is illustrated by the comparison in FIG.
• a widening of the channel leads to a broadening of the band when a substance is detected, assuming a Gaus-Pro Stahl.
• the comparison shows that the detection of the sample components in the channel system according to the invention with a high aspect ratio enables a significantly smaller bandwidth of the signals output by the detector to be achieved.
• the selectivity of the system is significantly increased. If the selectivity is assumed to be constant for a given sample throughput, it is consequently possible to increase the sample volume task.
• Figure 5 shows a mucrofluidic channel structure, the z. B. can be used in automated sample handling.
• the channel arrays (40) shoot a cavity (41) in which there is a suspension.
• a stirrer (42) which ensures permanent mixing of the suspension (43).
• the suspension is filled by selecting the appropriate channel widths, so that a feed rate (44) is passed to the channel outputs for further processing.
• a feed rate (44) is passed to the channel outputs for further processing.
• the channel widths of the respective channel arrays are selected to be of different sizes, so that feed rates of different quality are generated in accordance with a later area of application.
• FIG. 5 illustrates that the system according to the invention allows automatic sample handling even for microfluidic flows.
• the method according to the invention essentially does not impose any restriction on the shape and material of the microstructure, so that the system optimally suits the respective Application area can be adjusted.
• the system and method according to the invention prove to be suitable in fields of application in which channels with a high aspect ratio are advantageous.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Analytical Chemistry (AREA)
• General Engineering & Computer Science (AREA)
• Dispersion Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• General Health & Medical Sciences (AREA)
• Hematology (AREA)
• Clinical Laboratory Science (AREA)
• Mechanical Engineering (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Automatic Analysis And Handling Materials Therefor (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Micromachines (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=31501909

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (4)

Citations (2)

Family Cites Families (16)

• 2002
  • 2002-08-23 DE DE2002138825 patent/DE10238825A1/de not_active Ceased
• 2003
  • 2003-08-21 WO PCT/EP2003/009263 patent/WO2004018101A1/de not_active Ceased
  • 2003-08-21 JP JP2004530236A patent/JP4220466B2/ja not_active Expired - Fee Related
  • 2003-08-21 AU AU2003260439A patent/AU2003260439A1/en not_active Abandoned
  • 2003-08-21 DE DE50310870T patent/DE50310870D1/de not_active Expired - Lifetime
  • 2003-08-21 EP EP20030792404 patent/EP1534432B1/de not_active Expired - Lifetime
  • 2003-08-21 AT AT03792404T patent/ATE416030T1/de not_active IP Right Cessation
  • 2003-08-21 US US10/525,400 patent/US7156118B2/en not_active Expired - Fee Related

Patent Citations (2)

Also Published As

Similar Documents

Legal Events