Layer with a microstructured surface

Abstract

The invention relates to an extensive layer that is produced by a lithographic method and has perforations and a microstructured functional surface. The microstructured surface has a number of supporting, controlling and / or regulating structures in the size range from 10 nm to 100 μm, which, owing to their shape, can control a fluid medium into and through the perforations. The invention also relates to a device having the layer. The invention also relates to a method for producing the layer.

Description

[0001] Layer with microstructured surface

[0002] The invention relates to a layer having perforations, produced by a lithographic process and having at least one microstructured surface, a device comprising the layer and a method for producing the layer.

[0003] In biological research, diagnostics, medicine, or analytical procedures, it is often necessary to process and precisely separate samples or mixtures. Besides using centrifugal force, mixtures can be processed using gauze, paper filters, or sieve mesh, and gravity. Furthermore, individual substances or groups of substances can be separated or washed from a sample mixture by utilizing diffusion effects, as in dialysis (artificial blood purification). Membranes are also used, for example, to supply biological systems with nutrients, remove metabolic products, or as a growth matrix for biological films.

[0004] Filter systems used for processing simple and complex heterogeneous mixtures, such as blood, have been known for a long time. Originally, gauze and later mesh screens were used to separate and / or concentrate suspensions. Besides their lack of precision, the open filter area (porosity) of mesh screens is very low. In this context, porosity describes the sum of all the meshes of a filter surface in relation to the total surface area of ​​the filter material. In addition to mesh screens, there are filters made of metallic materials, which, due to their poor porosity, cannot be used for filtration of cells.

[0005] As an alternative to mesh, systems with pore sizes smaller than 10 pm can already be manufactured using plasma irradiation. However, membranes perforated by plasma irradiation have the significant disadvantage that the distribution of pores on the membrane surface is undefined and random. Consequently, to prevent pore overlap, the open filter area of ​​these membranes, similar to mesh, is very small. This small open filter area leads to rapid clogging of the pores. At the same time, this increases the already high pressure required to maintain filtration. This high pressure, in turn, negatively impacts certain filtration requirements, such as the separation of primary cells.

[0006] Another alternative is a polymer layer with a microstructured functional surface that has been processed by laser ablation (DE 10 2021 124 775 A1). Targeted laser bombardment allows pores to be introduced into the layer in a desired arrangement. However, the laser treatment leaves abrasion and soot marks on the layer, which impair the filtering quality.

[0007] The task is to improve the filter quality.

[0008] This problem is solved by a device according to claim 1, a device according to claim 12, and a method according to claim 13. Further advantageous embodiments and configurations of the invention are described in the dependent claims, the figures, and the exemplary embodiments. The embodiments of the invention can advantageously be combined.

[0009] A first aspect of the invention relates to a planar layer with a first and a second side, at least one side of which has a porous and microstructured surface. The layer has perforations with a diameter in the range of 100 nm to 30 pm of a defined shape, distributed in the material of the layer such that the layer has perforated and non-perforated areas. The layer comprises at least one layer and is produced by a lithographic process. The microstructured surface of the layer has a number of supporting, controlling, and / or regulating structures in the size range of 10 nm to 100 pm, which, by virtue of their shape, control the fluid medium in and through the perforations.The invention is advantageous because the layer produced by a lithographic process is clean compared to similar, conventional layers, which are also manufactured under cleanroom conditions. Compared to conventional layers processed with laser beams, the layer according to the invention exhibits no soot residue or abrasion. The wafer technology, known from the field of electronics and microelectronics technology, can be used to produce the layer. This process is carried out in a cleanroom, which further promotes the cleanliness of the layer being produced.

[0010] Furthermore, lithographically produced layers are advantageous because their production requires fewer steps than conventional layers, resulting in a time advantage, as more layers can be produced in a given time.

[0011] Another advantage of lithographically produced layers is that they can be manufactured with a uniform thickness, and the pores also have a uniform size and shape. Nevertheless, it is advantageously possible to vary the thickness of a layer across different areas. This allows for pores of varying sizes and shapes within a single layer.

[0012] The supporting, controlling, and / or regulating structures are also referred to as microstructures. These can, for example, advantageously control and monitor the permeability of a layer, monitor the stability of a layer, and generate signals upon contact with defined substances. The microstructures can also be components known from micro-optics, microfluidics, photonics, and other fields. Advantageously, the structures have a funnel-like shape to facilitate the flow of fluids into the performance components. The surface can have a relief and various textures. The surface can resemble a grater, such as those used in kitchens.

[0013] Preferably, the layer has a thickness between 500 nm and 100 pm, which varies across the entire surface of the layer. The thickness should be chosen so that the layer meets the requirements and can be easily processed in the desired equipment, while also being stable enough to withstand certain conditions, such as varying pressures, and thus not be damaged, for example, by cracking. The thickness of a layer can be selected depending on the overall dimensions, with a thinner layer being more stable over a relatively small area than over a relatively large area.

[0014] The perforations can also be described as pores or openings. The terms are used synonymously here.

[0015] Preferably, the layer is designed as a film. In this sense, it is formed as a thin, planar layer that is permeable for process separation. The layer can be produced with the smallest possible thickness, which allows for a shorter length of the pore channels compared to conventional sieve fabrics. This advantageously means that, with comparatively smaller pore opening cross-sections, less force is required to transfer the substances from one side of the layer to the other. The required pressure is reduced and therefore no longer has a detrimental effect on complex biological systems, such as primary cells.

[0016] Unlike conventional materials, the geometric shape of the perforations can be variably designed. It can be rectangular or circular. The size of the geometric shape can be reduced to at least a circular area, meaning the diameter of the pores can be advantageously provided depending on the desired application. Preferably, the pores have a diameter in the range of 400 nm to 20 pm, also preferably in the range of 500 nm to 10 pm, also preferably in the range of 600 nm to 5 pm, also preferably in the range of 700 nm to 3 pm, also preferably in the range of 800 nm to 2 pm, and also preferably in the range of 900 nm to 1 pm. Other possible, also preferred, pore diameters are in the range of 200 nm to 800 nm, 200 nm to 600 nm, 200 nm to 400 nm, and 250 nm to 300 nm.The different diameters allow for a specific filter selectivity with respect to certain molecules, macromolecules or cells.

[0017] Preferably, the layer has perforations whose defined shape is selected from the group comprising round, oval, and angular shapes, or freeform shapes produced by a combination of these shapes. This gives the perforations properties that are not found in the meshes of conventional screen fabrics, which are always angular by design. All shapes can be provided simultaneously in a single layer. The perforations can be evenly or unevenly distributed within the layer.

[0018] Furthermore, the perforations are preferably shaped differently across the cross-section of the layer. This means that their diameter and shape change as they extend through the layer. For example, they can be wider in the middle or have a different shape than in the surface area. Various perforation or pore configurations can be present in a layer according to the invention to filter different substances or molecules from a liquid.

[0019] In particular, the pores are arranged such that they form squares on the surface of the filter layer, separated by ridges. In other words, these ridges define the areas between the squares. The ridges are advantageously suitable for arranging further elements, e.g., the conductive pathways mentioned below.

[0020] Preferably, at least one side of the layer has electrical conductors. These conductors are exemplified as metallic strain gauges, produced, for instance, by additive manufacturing such as 3D printing. The conductors advantageously allow for the control of the perforations to open or close them electrically. They can also be used for resistance measurement. The determination of the resistance is based on the change in length and cross-section of the metallic strain gauges. When the strain gauges are stretched, the resistance increases. Thus, resistance measurement can be used to monitor various process sequences. For example, an increasing resistance can indicate that the filter layer is becoming clogged. Actively measuring the resistance makes it possible to directly control the process.Options in the process chain could include reducing the flow through the equipment, backflushing the equipment, or even shutting down the corresponding system connected to the equipment to prevent a breakthrough. If the layer is completely destroyed, the flow through the equipment can be stopped directly.

[0021] Preferably, the microstructures are flap-like. In a first operating state of the layer, the flap-like microstructures are open, and in a second operating state, they are closed. Preferably, the flap-like microstructures are controllable. In particular, the flap-like microstructures are controllable by an electric current and can thus preferably be opened or closed by applying an electric current. This configuration corresponds to the concept of "smart films." Alternatively, and also preferably, the flap-like microstructures can be controlled by the flow direction of the medium to be filtered. In this case, no electric current needs to be applied. Flow in one direction opens the flap-like microstructures. If the flow occurs in the other direction, the flap-like structures are closed. The system can thus function as a backflow preventer or check valve.

[0022] The microstructured functional surface advantageously enables the use of the device according to the invention in filtration or separation devices as well as in systems where the microstructured surface is used as a permeable partition between at least two systems. The invention improves the use of filtration devices with regard to the separation of biological and non-biological mixtures of substances, which primarily contain pressure-sensitive components, such as primary cells, cell clusters, speroids, bacteria, bioparticles, or vesicles, in the micro- and nanometer range. In addition to general filtration applications, the invention, through the defined size and distribution of the microstructures, opens up and improves its use in medically complex systems that require certified and highly regulated application.

[0023] The microstructures are advantageously selected from a group comprising raised geometries, recessed geometries, and feeder geometries. The term "geometries" is used here to refer to the supporting geometries. These geometries control the capillary flow, thus supporting, for example, accelerating or slowing down, the filtration through the filter layer according to the invention. This allows, for example, small particles to migrate quickly through the pore, while larger particles simply lack the time or the flow to even reach the pore in the first place.

[0024] The structures with raised geometries advantageously feature hemispheres, pyramids, pyramids with rounded tips, cones, cones with rounded tips, and / or cylinders. Raised geometries influence not only the flow towards the pore but also the flow across the pore. In this technical context, which is relevant, for example, in a cross-flow filter, blockage of the pores could be prevented. This improves the service life of the filters, as the pores do not clog as quickly and therefore do not need to be replaced as often.

[0025] The depressing geometries advantageously have non-perforating ablations. The feeding geometries advantageously have a scoop-like shape. In other words, the supporting geometries can be designed in the form of scoops, thus providing a feed to the pore. The advantages of each are the same as those of the raised geometries.

[0026] Preferably, at least one side of the layer has a surface coating. The properties of the layer can be advantageously modified by a suitable coating. The coating is preferably purely chemical, although alternatively a biochemical coating with, for example, macromolecules, peptides, or proteins can be provided, which can be used, for example, as capture molecules, tumor markers, or markers related to environmental analysis. Modification via electron beam irradiation is preferably used for the coating. Electron beam modification is independent of the pores and does not change their size. Simultaneously, the wettability of the layer can be subsequently modified. Since this method can be carried out without the use of toxic substances, its application in medical applications, for example, by improving hemo- or biocompatibility, is realistic.

[0027] Preferably, both sides of the layer according to the invention have a coating. Both layers can have the same coating. Particularly preferably, the coating of the first side and the coating of the second side are designed differently.

[0028] The layer material is advantageously suitable for the lithography process. In one embodiment, the layer material can comprise a polymer. The layer itself can also consist entirely of the polymer. Certain polymers are particularly well-suited for curing by UV light irradiation in a stereolithographic process. Therefore, the polymer is, in particular, a light-curing plastic, such as an acrylic, epoxy, or vinyl ester resin. Furthermore, the layer material can comprise or consist of renewable materials. In particular, the polymers of the layer can be derived from renewable materials.

[0029] The layer according to the invention preferably has at least two layers; it may also have more than two layers. A multilayer structure enables the formation of complex perforations with self-defined structures.

[0030] A second aspect of the invention relates to a device for filtering a medium, which has a layer according to the invention, wherein the layer is arranged between an upper and lower region of the device and the upper and lower regions form a supply line and a discharge line for the medium, such that the layer is located in the flow path of the medium. The medium is particularly a fluid medium, and in particular liquid or gaseous.

[0031] The lithographically produced layers can be provided individually. In particular, they are provided as part of a device according to the invention. The device is manufactured, in particular, by injection molding. The layer can be inserted directly into the injection mold from a roll-to-roll process during its manufacture. However, the layer can also be inserted into the device subsequently. Thus, the manufacturing of the device does not necessarily begin with the layer.

[0032] Preferably, the filter layer is arranged between an upper and lower section of the device, with the upper and lower sections forming a supply line and a discharge line for the fluid medium, respectively, so that the filter layer is located in the flow path of the fluid medium. This advantageously allows the device to be used in systems that include the filtration or osmosis of a fluid medium, e.g., in cell culture systems or dialysis equipment.

[0033] The layer in the device is used primarily for filtration and is suitable for both cake and cross-flow filtration. The device can be used as a sieve or filter.

[0034] The device enables, for example, advantageous use in laboratory filters, filter cascades, systems for the separation of functionalized bioparticles, cell culture approaches (for skin models, 3D epithelial cultures, investigation of chemotaxis, transmigration assays or, for example, in transport and polarity studies), in extracorporeal systems (e.g., in dialysis systems, or in systems in which personalized cells are used, cultivated as monolayers and thus serve to support the body's own functions) and in filter systems for the enrichment of bacteria for diagnostic purposes.

[0035] The setup can be advantageously used, for example, for cultivating biological films. In this sense, the setup can be used as a growth matrix for biological systems. The pores of the layer can serve, for example, to supply and / or remove metabolic products from living organisms. The setup can also be used to determine biological metabolic parameters. For example, when cultivating a monolayer (meaning that the cells adhere to an available substrate, such as glass surfaces or the plastic base of the culture vessel, and can only multiply and spread under these conditions; this is the common culture and growth form for most animal cells), the functional surface can support the formation of the cells' natural polarity and morphology.At the same time, when used in cell culture applications, the supply and disposal of cells can take place through the functional surface.

[0036] The layer according to the invention, with microstructured functional surfaces, can be advantageously used in filtration or separation devices in the nano-, micro- to millimeter-scale range, as well as in systems where the microstructured surface serves as a permeable partition between at least two systems. The invention improves the use of filtration devices for separating biological and non-biological mixtures, which primarily contain pressure-sensitive components, such as primary cells, bacteria, bioparticles, or vesicles, in the micro- and nanometer range. In addition to general filtration applications, the invention, through the defined size and distribution of the microstructures, opens up and improves its use in medically complex systems that require certified, highly regulated application.

[0037] In an advantageous embodiment, the device according to the invention is designed as a lab-on-a-chip system. In lab-on-a-chip systems, the microstructured surface of the inventive layer of the device advantageously acts as a filter within the system. Conventionally, for example, in the analysis of whole blood, the blood is often filtered first to enable subsequent analyses of the blood serum. Since the transport of the sample material in these microfluidic systems is partially achieved by capillary forces, high pressures cannot be used to separate cellular components from the blood serum. Filter materials with low porosity, such as filter fabrics or plasma membranes, are therefore unsuitable.Furthermore, when using filter media, which are often employed for separating blood components, it is important to note that in addition to fluid absorption, which is not insignificant with very small sample volumes of, for example, 20 pl, they also bind proteins and thus the analyte from the blood serum in a non-specific manner. Besides the filter materials, the separation could be further enhanced by centrifugation. However, since this process requires a centrifuge and therefore involves additional technical effort, the desired simplicity of these systems is negated. In contrast, in a lab-on-a-chip system with a device according to the invention, the arrangement and geometry of the pore openings can be specifically adapted to microfluidic filtration. Moreover, the functional surface can be selected and modified to prevent non-specific protein binding.The functional surface thus opens up new design possibilities and therefore a wider range of applications.

[0038] A third aspect of the invention relates to a method for producing a layer according to the invention, comprising the steps:

[0039] - Provide a negative mold that corresponds to the layer,

[0040] - Pouring a liquid that hardens through UV radiation into the negative mold,

[0041] - Hardening of the liquid by UV radiation,

[0042] - Removing the hardened layer from the negative mold.

[0043] The advantages of the method correspond to the advantages of the layer according to the invention. Particularly advantageous is the provision of all structural features of the layer via the negative mold, in particular the shape, size and arrangement of the pores and the formation of the microstructured surface.

[0044] Subsequently, in an advantageous embodiment of the method, the surface of at least one side of the layer can be modified by an additive process and / or a chemical process.

[0045] The layer can be introduced into a device, e.g., a filter device, and can be introduced during the device's manufacturing process. The invention is explained in more detail with reference to the figures. They show

[0046] Figure 1 shows a schematic representation of an embodiment of a device according to the invention in external view (A) and in cross-section (B).

[0047] Figure 2 shows a schematic representation of the surface of a filter layer with a defined shape and distribution of perforations.

[0048] Figure 3 shows a schematic representation of a surface of an embodiment of the filter layer, together with an enlarged section.

[0049] Figure 4 shows a schematic representation of a surface of an embodiment of the filter layer, together with an enlarged section.

[0050] Figure 5 shows a comparative schematic representation of the surfaces of a filter layer without (A) and with (B) ribs.

[0051] Figure 6 shows a schematic representation of a surface of an embodiment of a filter layer with applied conductive tracks, together with an enlarged section.

[0052] Figure 1 shows different types of perforations in a filter layer (A to G). Figure 8 shows different possible arrangements of perforations on the surface of a filter layer (A to E).

[0053] Figure 9 shows different forms of perforations in an embodiment of a layer according to the invention (A to H).

[0054] Figure 10 shows different forms of perforations in a further embodiment of a layer according to the invention (A to C).

[0055] Figure 11 shows different forms of perforations in a further embodiment of a layer according to the invention (A to D).

[0056] Figure 12 shows an embodiment of a layer according to the invention.

[0057] Figure 13 shows a further embodiment of a layer according to the invention.

[0058] Figure 14 shows a schematic representation of another embodiment of a device according to the invention.

[0059] Figure 15 shows a schematic representation of another embodiment of a device according to the invention.

[0060] Figure 16 A flowchart of an embodiment of the method according to the invention.

[0061] Figure 17 shows a flowchart of another embodiment of the method according to the invention.

[0062] Figure 1 shows an embodiment of a device 1 according to the invention. In the embodiment shown in Figure 1A, the device 1 has a housing 2. A layer 10, corresponding to a filtering layer according to the invention, is arranged in the interior 3 of the housing 2. Due to its design, the layer can also be referred to as a film; the terms layer and film are used synonymously hereafter. In Figure 1A, the film 10 is arranged without a support matrix, i.e., it was incorporated directly into the housing 2 during the manufacturing process.

[0063] In the embodiment according to Fig. 1B, the housing 2 has an upper housing part 4 and a lower housing part 5, which can be reversibly connected to each other, e.g. by a screw closure. Here, the film 10 is arranged in the upper area of ​​the lower housing part 5. The film 10 is arranged on an insert 6, which functions as a support matrix for mechanical stability.

[0064] In an alternative embodiment, the film 10 can also be combined with the insert 6 in such a way that the film 10 is directly incorporated into the insert 6 and then firmly connected to it. If the housing parts 4, 5 are each modified with two inlets and outlets, the device 1 can be used as a cross-flow filter.

[0065] Figure 2 shows the film 10. The film 10 consists of an acrylic resin that has been photolithographically cured. Alternatively, the film 10 can also consist of other resins, e.g., an epoxy or vinyl ester resin, or other materials, or at least incorporate them.

[0066] The thickness of film 10 is 10 pm. Alternatively, the layer thickness can be thinner or thicker, selected from the range of 500 nm to 100 pm; it can be chosen to meet the desired requirements. The dimensions in height and width are also freely selectable according to the intended application and can be, for example, 10 cm (height) and 8 cm (width).

[0067] The film 10 has 20 perforations. These 20 perforations can also be referred to as pores or openings. The terms are used synonymously here.

[0068] The pores 20 are rectangular in shape and arranged in an ordered pattern in defined rows on the surface 30 of the film 10. The pores 20 have a diameter of 800 nm. The film 10 features a number of supporting, controlling, and / or regulating microstructures in the size range of 10 nm to 100 pm (see protrusions 110 in Fig. 10). Due to their shape, the microstructures can control a fluid medium in and through the perforations 20.

[0069] Fig. 3 shows the film 10 according to Fig. 2 in more detail. For this purpose, the film 10 is shown with an enlarged section A. The pores 20 are arranged in rectangular squares 21 consisting of 24 (4x6 rows) pores 20. A space is formed between each square 21. The squares 21 are evenly distributed over the surface 30 of the film 10.

[0070] Fig. 4 shows a further embodiment of the film 10 according to the invention with hexagonal pores 20, with an enlarged section A. The pores 20 are formed in 3 / 4 / 3 arrangements, which in turn form complexes in a 3 / 4 / 4 / 3 arrangement.

[0071] Figure 5 shows a comparison of two pore distribution configurations. In Figure 5A, the pore distribution in the film 10 corresponds to Figures 1 and 2. The pores 20 are arranged in squares 21, which are delimited from one another but only slightly spaced apart. In Figure 5B, the spaces between the squares 21 are more pronounced. The areas between the squares 21 are also referred to as webs 22.

[0072] The webs 22 act as placeholders on which, for example, conductive traces 23 can be arranged (Fig. 6). The design of the conductive traces 23 allows for the dissipation of resistances. Conductive traces 23 can be arranged in all webs 22. Alternatively, conductive traces can also be arranged in only some webs. An enlarged section in Fig. 5 shows a more detailed view of the pores 20 and conductive traces 23.

[0073] The pores 20 can have any shape other than the rectangular shape shown in Figs. 2-3, 5, and 6, and the hexagonal shape shown in Fig. 4. Fig. 7 shows examples of various possible pore shapes: A) rectangular, B) cruciform, C) circular, D) a combination of circular and rectangular, E) oval, F) a combination of oval and rectangular, G) a combination of triangular and rectangular, essentially triangular. Other shapes are possible. Fig. 8 shows ways in which the pores 20 of the same or different shapes can be arranged in the film 10. The arrangements are shown as squares 21. In Fig. 8A, triangular pores 20 are arranged alternately with their pointed or flat sides facing each other. In Fig. 8B, unlike in Fig. 8A, the triangular pores 20 are arranged such that their pointed sides are offset from each other, so that the points lie next to each other and not facing each other.In Fig. 8C, rectangular pores 20 are arranged in a square 21 such that in the upper and lower rows, eight pores 20 are arranged with their long sides facing each other, and in the two middle rows, three pores 20 are arranged with their short sides facing each other. In Fig. 8D, the pores of the two middle rows are arranged as in Fig. 8C. The pores 20 of the upper and lower rows are arranged similarly to Fig. 8C, with their long sides facing each other, but in a slightly inclined shape (upper row inclined to the left, lower row inclined to the right). In Fig. 8E, three rows of three rectangular pores 20 each are arranged with their short sides facing each other. Alternating between the rows of rectangular pores 20, a row of circular pores 20 is arranged.

[0074] It is clear that the pore shapes and arrangements of the pores 20 are not limited to the examples shown. Further combinations in the formation and arrangement of the pores 20 are possible.

[0075] Fig. 9 shows different pore shapes in one embodiment of a film 10 according to the invention. It is clear that only sections of the film 10 according to the invention are shown here. The embodiment shown in Fig. 9 depicts a single-layer film 10.

[0076] In one example, the pores are trapezoidal in cross-section (Fig. 9A) and round in plan view (Fig. 9B); in another example, slightly rounded in cross-section (Fig. 9C) and round in plan view (Fig. 9D); and in yet another example, straight through in cross-section (Fig. 9E) and round in plan view (Fig. 9F), rectangular (Fig. 9G), or alternating round and rectangular (Fig. 9H). Fig. 10 shows a single-layer embodiment of the film 10 according to the invention, in which microstructures in the form of protrusions 110 are shown in the surface of the film 10 in the area of ​​the pores 20. The protrusion 110 can, for example, appear rectangular in cross-section and also rectangular in plan view, as shown in Fig. 10A (Fig. 10B). Another form of elevation 110 is shown in the three-dimensional representation of Fig. 10C, wherein the elevation 110 arches slightly over the pore 20.

[0077] Figure 11 shows various pore shapes in an embodiment of the film according to the invention with two layers 100. The film 100 has a first layer 101 and a second layer 102 (Figure 11A). The two layers 101 and 102 each have a different material. For example, the material of the first layer can be a polymer, and the material of the second layer 102 can be a carrier material made of a polymer or a metal. The carrier material of the second layer functions, for example, as a support structure and can, for example, be a mesh fabric. Alternatively, the layers 101 and 102 can also have the same material.

[0078] The pores in the film 10 according to Fig. 11 are shown in cross-section in Fig. 11A. In plan view, they can be, for example, round (Fig. 11B) or rectangular (Fig. 11C). In Fig. 11D, conductive pathways 23 are additionally shown, arranged in the film 10, analogous to the configuration according to Fig. 11B.

[0079] Figure 12 shows a further embodiment of a film 10 according to the invention. In this embodiment, the film 10 has a first layer 101, a second layer 102, and a third layer 103. The layers can be made of the same material, or alternatively, each layer can be made of a different material. It is also possible for two layers to be made of the same material and the third layer to be made of a different material.

[0080] Figure 13 shows an embodiment of the film 10 according to the invention, comprising four layers 100: a first layer 101, a second layer 102, a third layer 103, and a fourth layer 104. The middle layers 102 and 103 can be made of the same material or of different materials. The first layer 101 and the fourth layer 104 have chemical (or possibly biochemical) modifications applied during the manufacturing process. The first and fourth layers 101 and 104 can have the same modifications or different modifications.

[0081] Figure 14 shows an embodiment of a system 40, which comprises a device 1 with two layers 10, namely a first (lower) layer 11 and a second (upper) layer 12. Here too, the aforementioned layers are designed as films and are synonymously referred to as films. In Figure 8, the system 40 represents a sieve system. A connector 41 connects the device 1 to a collection vessel 42 and allows the connection of a filter support system. A funnel 43 is arranged in the upper region of the system 40, which is provided for increasing the feed volume of a medium to be filtered.

[0082] The second film 12 can be arranged leak-proof above the first film 11. The two films 11 and 12 differ in at least one parameter, namely their porosity, such that the porosity of the second film 12 is greater than that of the first film 11. The second film 12 is optional; that is, the system 40 also functions with only the first film 11.

[0083] Figure 15 shows another embodiment of system 40. System 40 in Figure 9 represents a sieve system for a bottle-top filter. The first film 11 is arranged in a first sieve unit 45, and the second film 12 is arranged in a second sieve unit 46 located above the first sieve unit. Here, too, the two films 11 and 12 differ in at least one parameter, namely their porosity, such that the porosity of the second film 12 is greater than that of the first film 11. Again, the second film 12 is optional (correspondingly, the second sieve unit 46), meaning that system 40 also functions with only the first film 11.

[0084] In a process according to Fig. 16 for producing a film 10 according to the invention, a negative mold corresponding to the film 10 to be produced is provided in a first step S1. It is clear to those skilled in the art that a suitable device for arranging the negative mold and for the subsequent steps must be available and provided accordingly. All structural features of the film 10 are provided via the negative mold, in particular the shape, size, and arrangement of the pores 20 and the formation of the microstructured surface. In a second step S2, an acrylic resin is applied to the negative mold in a suitable quantity. The negative mold has the negative structures that the film 10 to be produced is to have. In a third step S3, the acrylic resin is cured by irradiation with UV radiation of approximately 200 pm.

[0085] In a fourth step S4, the hardened film 10 is removed from the negative mold. The film 10 can be directly inserted into a device 1. When manufacturing a suitable device 1 for filtering a fluid material, the planar film 10, produced by a lithographic process, can be inserted into a finished component, or even during the component's manufacturing process, e.g., when it is manufactured by injection molding.

[0086] In one embodiment of the method according to Fig. 17, in a fifth step S5, the surface of at least one side of the film is modified by an additive and / or chemical process. The surface modification of the film can take place before the film 10 is introduced into the device 1, or after completion of the entire manufacturing process of the device 1. The coating is applied, for example, with proteins or protein fragments (antibody epitopes) that are specific for antigens (e.g., tumor antigens) which bind to the peptides and can thus be diagnosed in a blood sample. [Reference numeral list]

[0087] 1. Facility

[0088] 2 cases

[0089] 3 Housing interior

[0090] 4 Housing top

[0091] 5 Housing lower part

[0092] 6 inserts

[0093] 10 shifts

[0094] 11 first shift

[0095] 12 second shift

[0096] 20 perforations

[0097] 21 squares of perforations

[0098] 22 Bridge

[0099] 23 Conduit

[0100] 30 Surface area of ​​the film

[0101] 40 System

[0102] 41 Connector

[0103] 42 Collection container

[0104] 43 funnels

[0105] 45 first sieve unit

[0106] 46 second sieve unit

[0107] An enlarged section

Claims

Patent claims 1. A planar layer (10) with a first and a second side, at least one of which has a porous and microstructured surface (30), the layer having perforations (20) with a diameter in the range of 100 nm to 30 pm with a defined shape, which are distributed in the material of the layer (10) such that the layer (10) has perforated and non-perforated areas, and the layer (10) has at least one layer and is produced by a lithographic process, characterized in that the microstructured surface (30) has a number of supporting, controlling and / or regulating microstructures in the size range of 10 nm to 100 pm which, due to their shape, control the fluid medium in and through the perforations (20).

2. Layer (10) according to claim 1, wherein the layer (10) has a thickness between exhibits 500 nm - 100 pm and is different over the entire area of ​​layer (10).

3. Layer (10) according to claim 1 or 2, which is formed as a film.

4. Layer (10) according to one of the preceding claims, wherein the defined The shape of the perforations (20) is selected from the group comprising round, oval, angular shapes or freeform shapes produced by a combination of the round, oval and angular shapes.

5. Layer (10) according to one of the preceding claims, wherein at least one The side of the layer (10) has electrical conductors (23).

6. Layer (10) according to one of the preceding claims, wherein the microstructures are flap-like, and the flap-like Microstructures are closed in a first working state of the layer (10) and open in a second working state.

7. Layer (10) according to claim 6, wherein the operating states of the flap-like microstructures are controllable.

8. Layer (10) according to one of the preceding claims, wherein at least one The side has a coating.

9. Layer (10) according to claim 8, wherein both sides have a coating, and the coating of the first side and the coating of the second side are designed differently.

10. Layer (10) according to any of the preceding claims, comprising at least two has layers.

11. Device (1 ) for filtering a medium, comprising a layer (10) according to any one of claims 1 to 10, wherein the layer (10) is arranged between an upper and lower region of the device (1 ) and the upper and lower regions form a supply line and a discharge line for the medium, such that the layer (10) is located in the flow path of the medium.

12. Method for producing a layer (10) according to one of the claims 1 to 10, with the steps: - Provide a negative mold that corresponds to the layer, - Pouring a liquid that hardens through UV radiation into the negative mold, - Hardening of the liquid by UV radiation, - Removing the hardened layer from the negative mold.

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