Method for producing electrically conductive structures on membranes and cell culture systems based thereon and equipped with sensors

Abstract

The invention relates to a method for producing electrically conductive structures on membranes and to cell culture systems based thereon and equipped with sensors, having the steps of: - providing a plastic film, which has a pressure-sensitive adhesive layer on one side, for example, wherein the plastic film preferably rests on a carrier, for example paper or plastic; - providing a plan (layout) for electrically conductive structures; - removing regions, in which the electrically conductive structures are arranged according to the plan, from the plastic film, for example by laser irradiation of the plastic film along the electrically conductive structures of the plan to produce a plastic film with openings according to the electrically conductive structures of the plan; - placing the plastic film with openings according to the electrically conductive structures of the plan on a membrane so that the plastic film adheres to the membrane; - sputtering conductive material onto the plastic film to apply conductive material to the plastic film and through its openings to the membrane, - peeling the plastic film from the membrane to produce a membrane with electrically conductive structures fixed thereon.

Description

[0001] T PAATENTKANWUALTTSKATNZLIESI

[0002] TARUTTIS - Aegidientorplatz 2b - D-30159 Hanover

[0003] Dr. rer. nat. Stefan Taruttis

[0004] European Patent Office, Graduate Engineer

[0005] Patent attorney

[0006] European Patent Attorney

[0007] 80298 MUNICH European Trademark Attorney

[0008] D-30159 Hannover, Aegidientorplatz 2b

[0009] GATEHOUSE AT AEGI

[0010] Tel.: ++49 511 123 32 670

[0011] Fax: +49 511 123 32 678 www.taruttis.com info@taruttis.com in cooperation with

[0012] Dr. rer. medic Dirk Vollmer

[0013] Patent Attorney, European Patent Attorney

[0014] D-74523 Schwäbisch Hall, Hilde-Domin-Str. 8

[0015] Symbol: Symbol: T1047PCT August 29, 2025

[0016] New international patent application for a manufacturing process for electrically conductive structures on membranes and sensor-equipped devices based thereon.

[0017] Manufacturing processes for electrically conductive structures on membranes and cell culture systems based thereon, equipped with sensors

[0018] The invention relates to a method for producing electrically conductive structures, e.g., conductor tracks, sensor surfaces, or electrodes, which are directly applied to membranes, the membranes obtainable by the manufacturing method on which the electrically conductive structures are applied, and preferably devices and systems for cell cultivation in which these membranes form a wall of a compartment. Preferably, the membranes have nanopores that extend through the entire thickness of the membranes, e.g., nano- or micropores formed by etching, e.g., by ion bombardment followed by etching in so-called ion track membranes. The method according to the invention has the advantage of producing electrically conductive structures, in particular sensor surfaces, electrodes, and conductor tracks, with high precision or resolution on membranes without clogging nano- or micropores.A further advantage is that the process fabricates electrically conductive structures from conductive material, e.g., gold, directly onto a membrane, without an adhesive layer, e.g., of chromium or titanium, between the membrane and the conductive track. The process is not photolithographic and does not require the use of photoresist. It also does not require a rigid shadow mask. The membrane is preferably thin and flexible and can be made of, for example, plastics such as PET, polycarbonate (PC), polyethylene, polypropylene, polymethyl methacrylate, polystyrene, or COC (cyclic olefin copolymer, available as TOPAS®). A membrane made of one of these materials has the advantage of being sufficiently transparent to visible light for microscopy and exhibiting sufficient tensile strength for handling during the process, even at thicknesses of, for example, up to 250 pm, up to 200 pm, up to 150 pm, up to 100 pm, up to 50 pm or less, e.g., up to 10 pm or less.

[0019] The process enables the fabrication of conductive structures by means of a sputter coating, such as magnetron sputtering of a conductive material, and is therefore applicable on a large scale. Preferably, at least two electrodes are applied as conductive structures on a common surface of the membrane, which are suitable, for example, for use in impedance measurement in the range of, for example, a few Hz to 1 GHz.

[0020] Tang et al., Front. Sens. 3:974895 (2022) describe a SiN membrane for cell culture consisting of a Si layer with a double-sided SiN coating, which is coated with photoresist. The photoresist is structured by laser pulses at the points where it is subsequently removed. These open areas in the photoresist are etched into the SiN layer by plasma etching to form nanopores with a diameter of 650 nm that extend through the SiN layer. The opposing SiN layer and the adjacent Si layer are removed by etching, leaving a SiN membrane with nanopores framed by the remaining Si layer.

[0021] EP 1 181 538 B1 describes a process for depositing electrode material onto a plastic substrate. This involves adhering a plastic film to the substrate using an adhesive layer. Patterns corresponding to electrodes are then cut from the plastic film using a cutting plotter or engraving device. The cut-out pieces are then removed from the plastic substrate, and electrode material is sputtered onto them. It is known that sputtering processes for applying structured conductive material to membranes require masks to cover exposed areas of the membrane. The mask must be positioned close to the membrane to produce conductive structures precisely and with acceptable resolution.

[0022] The invention aims to provide a manufacturing process and a membrane producible by means thereof, with electrically conductive structures that are applied to the membrane in high resolution, preferably directly or without an adhesive layer, and are bonded to the membrane. Preferably, the membrane should have nano- or micropores that are not blocked by the conductive structures. Preferably, the process should be implementable as a roll-to-roll process.

[0023] The invention solves the problem with the features of the claims and in particular with a method that combines the steps

[0024] - Providing a plastic film which preferably has at least one adhesive surface, e.g. having an adhesive layer on one side, wherein the plastic film preferably rests on a substrate, e.g. paper, plastic or metal,

[0025] - Providing a plan (layout) for electrically conductive structures, removing areas from the plastic film where the electrically conductive structures are arranged according to the plan, e.g.by laser irradiation of the plastic film along the electrically conductive structures of the plan to produce a plastic film with perforations according to the electrically conductive structures of the plan, optionally removing the carrier from the plastic film after producing a plastic film with perforations and before placing the plastic film onto a membrane, providing the membrane, placing the plastic film with perforations according to the electrically conductive structures of the plan onto a membrane so that the plastic film adheres to the membrane, wherein the plastic film preferably rests on a carrier when removing areas, so that the plastic film is subsequently brought into contact with the membrane while still resting on the carrier, e.g. placed on the membrane and / or pressed against the membrane, after the plastic film adheres to the membrane, removing the carrier from the plastic film.

[0026] Sputtering of conductive material onto the plastic film to apply conductive material to the plastic film and through its perforations onto the membrane, peeling the plastic film from the membrane to produce a membrane with electrically conductive structures fixed on it.

[0027] In general, the steps of the procedure describe the elements of a device for manufacturing the membrane and measuring chambers containing the membrane, which are set up to carry out the steps.

[0028] Preferably, the plastic film adheres to the membrane by means of pressure-sensitive adhesive, e.g., by means of an adhesive present on the plastic film. Preferably, the membrane has an adhesive on the surface with which it adheres to the membrane, while the opposite surface, with which the plastic film rests on the substrate, has no adhesive or also has an adhesive.

[0029] The support on which the membrane rests during the removal of areas according to the plan for electrically conductive structures can be a roll or a strip, e.g. made of paper, plastic, metal, wherein a strip can be a strip circulating around rollers or a strip moved from a supply roll on which membrane is stored to a pull roller.

[0030] It has been shown that removing areas from the plastic film while it is on a support to produce a plastic film with perforations, and subsequently placing the perforated plastic film onto the membrane, has the effect that the membrane is not affected during the removal of areas and that the plastic film can be peeled off the membrane after sputtering without leaving any residue of the membrane or its adhesive on the membrane.

[0031] The removal of areas from the plastic film according to the plan by laser irradiation is preferably carried out by laser ablation or laser cutting. Alternatively, the removal of areas from the plastic film can be carried out by cutting with a knife or by punching.

[0032] The conductive material can be a metal such as gold, platinum, silver, titanium, copper, or conductive carbon, or titanium nitride, or alternatively or additionally an electrically conductive metal oxide, e.g., indium tin oxide (ITO). Preferably, the conductive material is sputtered directly onto the membrane covered by the plastic film with its perforations, e.g., without prior application of an adhesion promoter layer to the membrane and / or without surface activation of the membrane, e.g., without prior plasma treatment of the membrane. Preferably, the conductive material is sputtered directly onto the membrane covered by the plastic film with its perforations, with surface activation of the membrane prior to the application of the conductive material by sputtering.

[0033] The sputtering process is preferably magnetron sputtering. It has been shown that the electrically conductive structures deposited onto the membrane using this method exhibit good conductivity and adhesion, which is attributed to the fact that high-energy ions impact the membrane during sputtering and that the electrically conductive structures consist of high-density conductive material.

[0034] Preferably, the membrane has nano- and micropores; in particular, the membrane is an ion track membrane. It has also been shown that the method does not close the nano- and micropores of the membrane, but rather that the membrane has electrically conductive structures through which the nano- and micropores are accessible, and / or that the membrane has electrically conductive structures in which the nano- and micropores continue.

[0035] In general, the membrane can be surface-activated before sputtering, e.g., before applying the perforated plastic film to the membrane, or preferably after applying the perforated plastic film to the membrane, in order to strengthen the bond of the sputtered conductive material to the membrane. Surface activation can be achieved, for example, by contacting the membrane with an oxygen plasma, preferably a dielectrically hindered plasma, e.g., 200 W / cm². 2For 5 minutes, the oxygen flow rate is 50 sccm. Surface activation using an oxygen plasma, when the plastic film is already positioned on the membrane, also increases the adhesion of the conductive material sputtered onto the plastic film, without affecting the adhesion or adhesive bond of the plastic film to the membrane. Preferably, the removal of parts of the plastic film that are completely enclosed by a perforation can be achieved by applying a second plastic film with an adhesive surface to the plastic film after sputtering, followed by peeling off the second plastic film with the plastic film and its perforations, which is adhered to it, from the membrane.

[0036] The plan for electrically conductive structures preferably includes electrically conductive structures with a width down to 20 pm and a spacing of 20 to 50 pm. Preferably, the plan includes at least two separate electrically conductive structures, each with a terminal.

[0037] Preferably, the plastic film is arranged on a carrier, the plastic film remaining on the carrier until the plastic film is in contact with the membrane and the carrier is then removed from the plastic film, e.g., by peeling the carrier off the plastic film. This has the advantage that the design for electrically conductive structures and the plastic film with perforations according to the electrically conductive structures of the design can contain parts that are completely separate from the rest of the plastic film, e.g., parts of the plastic film that are completely enclosed by a perforation, so that these parts are not connected to the rest of the plastic film. Generally, the carrier is preferably flexible so that the plastic film can be wound from a roll, also referred to as a supply roll, and onto a reel, also referred to as a draw roll, while it rests on the carrier.

[0038] After applying conductive material to the surface of the membrane, to which the plastic film adheres by means of pressure-sensitive adhesive, using sputtems, the plastic film can be removed from the membrane, leaving electrically conductive structures in the area of ​​the perforations in the plastic film on the membrane. In embodiments in which the plastic film contains parts that are completely enclosed by a perforation, such parts can be removed from the membrane by applying a second plastic film with a pressure-sensitive surface to the membrane and then peeling it off.Because the conductive material adheres more strongly to the membrane and the plastic film than the plastic film adheres to the membrane, parts of the plastic film adhering to the membrane, which are completely enclosed by a perforation and may be sputtered with conductive material, adhere to the second plastic film and are removed from the membrane along with it. Alternatively or additionally, parts of the plastic film adhering to the membrane, which are completely enclosed by a perforation, can be removed from the membrane by laser irradiation, also known as laser ablation.

[0039] The procedure is preferably carried out as a role-to-role procedure, e.g.by providing the plastic film, which rests on a carrier, in the form of a roll; passing the plastic film under a laser beam, a knife, or a punch to remove areas in which the electrically conductive structures of the plan are arranged from the plastic film, preferably whereby the plastic film with the perforations produced according to the plan remains on the carrier or alternatively the plastic film is detached from the carrier; applying the plastic film to a membrane which is unwound from a roll so that the plastic film adheres to the membrane, preferably by means of pressure-sensitive adhesive; sputtering conductive material onto the surface of the membrane covered by the plastic film, optionally with continuous feeding of the membrane through a sputtering system; and subsequently winding the membrane with the plastic film on it onto a pulley.In general, in embodiments where the plastic film remains on the substrate after the removal of areas containing the electrically conductive structures of the design, the plastic film is preferably applied to the membrane with its adhesive surface, and the substrate can then be peeled off the plastic film, so that the plastic film is adhesively bonded to the membrane without the substrate. Alternatively, after the removal of areas containing the electrically conductive structures of the design, the substrate can be separated from the plastic film, e.g., peeled off, and the plastic film can be applied to the membrane without the substrate and subsequently sputtered with conductive material.

[0040] In general, the perforations in the plastic film can be created by completely removing the perforations through area ablation during laser irradiation of the plastic film according to the electrical lines of the plan, or by separating them from the rest of the plastic film by laser irradiation along the outlines of the perforations while the plastic film is resting on a substrate, and then peeling the plastic film off the substrate without the removed or separated parts. The parts separated along their outlines remain on the substrate.

[0041] The invention further relates to a device whose parts are configured to carry out the steps of the method. Preferably, a device comprises a supply roll for plastic film arranged on a carrier, a pull roller configured to wind up the carrier at the end of its path, the path of the carrier extending between this supply roll and this pull roller, a supply roll for the membrane, a pull roller for the membrane configured to wind up the membrane at the end of its path, a laser in the path of the carrier which is controlled for removing areas from the plastic film by laser irradiation of the plastic film according to a plan for electrically conductive structures while the plastic film is arranged on the carrier, and a device for placing the plastic film onto the membrane arranged in the path of the carrier between the laser and the pull roller for the membrane.a section arranged in the path of the carrier between the application device and the pull roller for the membrane, which is configured for peeling the carrier from the plastic film, a sputtering unit arranged in the path of the membrane between the section configured for peeling the carrier from the plastic film and the pull roller for the membrane, which is configured to apply electrically conductive material to the plastic film resting on the membrane, and preferably a section arranged in the path of the membrane between the sputtering unit and the pull roller for the membrane, which is configured for peeling the plastic film from the membrane, with a pull roller for the plastic film.

[0042] The laser irradiation of the plastic film preferably takes place as pulsed laser radiation, e.g. laser radiation from a picosecond laser or femtosecond laser, preferred wavelength 515 nm.

[0043] The plastic film preferably has a thickness of 75 to 100 µm. The plastic film can be made of, for example, polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyolefin (e.g., polyethylene), or polypropylene. The adhesive surface of the plastic film can be a UV-curing acrylate, or rubber- or silicone-based, allowing the plastic film to be removed from the membrane without leaving any residue. Removal, e.g., peeling, of the plastic film from the membrane can be achieved by applying heat, e.g., to 90 to 170 °C, and / or UV irradiation. The backing for the plastic film can be made of PET, polyolefin, or paper.

[0044] Sputtering can be carried out, for example, with an argon flux of 0.089 sccm at a power of 200 W for 50 s.

[0045] The membrane can, for example, have a thickness of 0.3 to 10 pm.

[0046] Preferably, the membrane with electrically conductive structures attached to it is arranged between two chamber plates to form a measuring chamber, also called a compartment, in which eukaryotic, e.g., animal, but also prokaryotic cells can be cultivated. Each chamber plate has recesses that form chambers adjacent to the membrane. The chamber plates are each covered by a cover plate, which covers the chambers and seals them off from the membrane. The recesses in the chamber plates preferably have areas covered by bores in the cover plates, so that the bores form access lines through the cover plates to the recesses. The bores in the cover plates preferably have connections for lines, e.g., for medium and / or gas. The electrically conductive structures form, for example,Spaced electrodes are arranged on a surface of the membrane and have connecting tabs that project beyond the chamber plates and optionally beyond the cover plates, so that the connecting tabs can be connected to an electrical measuring device, e.g., by means of a plug connector. A measuring chamber thus produced, in which a membrane produced according to the invention, which has at least two separate electrically conductive structures on one surface and pores extending through its thickness, is arranged between chamber plates that have recesses and are each covered by a cover plate opposite the membrane, in which bores with connections are arranged as conductors for penetration, is suitable as a measuring chamber for use in the cultivation of cells in the recesses. The chamber plates and the cover plates can be made of plastic, silicon, or glass, either independently of each other or all in the same material.Preferably the membrane consists of polymer material and has continuous micro- or nanopores through its thickness, and the chamber plates and the cover plates consist of silicon or glass, wherein preferably the membrane, the chamber plates and the cover plates are connected to each other by bonding.

[0047] Alternatively, a measuring chamber can be comprised of an insert with a base made of the membrane produced according to the invention, wherein the insert is arranged in a cup and has a wall that projects beyond the cup, such that the base of the insert is arranged at a distance from the base of the cup. The general design of such inserts for arrangement in cups is known with other membranes or without electrically conductive structures under the name Transwell (Corning, USA).

[0048] Preferably, a measuring chamber, and more preferably at least two, e.g., up to 96, parallel measuring chambers are used in a method for the electrical measurement of cells. Cells can be cultured in a recess of a chamber plate and / or in an insert arranged in a well. Generally, the same recess in which cells are cultured and / or the recess of the opposite chamber plate, or the space between the membrane-formed base of an insert and the well, can be filled with medium and / or gas, optionally through which medium and / or gas flows. Cells, identical or different, can be cultured in separate recesses, separated only by an intermediate membrane, to allow, for example, metabolic products from one recess to pass through the membrane into the other without the cells from the membrane-separated recesses coming into direct contact.

[0049] The membrane that can be produced using the method according to the invention is suitable for cell culture systems in which the membrane forms a wall and the electrically conductive structures arranged on the membrane are connected to an electrical measuring device, e.g. for impedance measurement.

[0050] The electrical measurement is preferably an impedance measurement, e.g., at a frequency of a few Hz, e.g., 10 to 100 Hz, up to 1 GHz. The invention will now be explained with reference to the figures shown in

[0051] Fig. 1 a schematic exploded view of a measuring chamber, Fig. 2 a microscopy image (scale bar 10pm) of a porous membrane with a metallic, electrically conductive structure applied according to the invention,

[0052] - Fig. 3 a) and b) Measured values ​​of impedance measurements in a measuring chamber, Fig. 4 schematically a device set up for carrying out a roll-to-roll manufacturing process,

[0053] - Fig. 5 schematically shows another device set up for carrying out a roll-to-roll manufacturing process,

[0054] - Fig. 6 schematically shows another device set up for carrying out a roll-to-roll manufacturing process and

[0055] Fig. 7 schematically shows a device set up for carrying out a roll-to-roll manufacturing process for the production of measuring chambers.

[0056] Figures 1A and 1B show a measuring chamber with a membrane 3 produced according to the invention, which has continuous nanopores and conductive traces 4 arranged on one surface of the membrane 3. These traces form two spaced-apart electrodes and have terminal tabs 7 that can be connected to a measuring device 5, e.g., for impedance measurement. The membrane 3 is arranged between two chamber plates 2, each of which has recesses 6 located in the area of ​​the electrodes formed by the conductive traces 4. The chamber plates 3 are covered on their surface opposite the membrane 3 by cover plates 1, which close the recesses 6 from the membrane 3 in order to form chambers in which cells can be cultured. The cover plates 1 have bores 8 that form access lines opening into the recesses 6 of the chamber plates 2 and connections accessible from the outside.Membrane 3 can be liquid-tightly bonded to chamber plates 2 and cover plates 1, for example, by providing adhesive surfaces on both sides of the chamber plates 2. A liquid-tight connection between membrane 3 and chamber plates 2 and cover plates 1, which are made of polymer material (e.g., PET, PC, PMMA, polystyrene, COC) or glass, can be achieved by bonding. Generally, a membrane can be formed in one piece or integrally with at least one of the chamber plates. Example 1: Production of a membrane with electrically conductive structures.

[0057] As an example, a 0.5 pm thick membrane with continuous nanopores produced by ion track etching was sputtered with gold. Sputtering was performed at an argon flux of 0.089 sccm at a power of 200 W for 50 s. Before sputtering, a plastic film (blue saw-cut foil, available from DISCO HI-TEC EUROPE GmbH) was applied to the membrane. This film had been laser-irradiated (pulse frequency 100 kHz, 515 nm) with openings according to a design for electrically conductive structures. After sputtering, the plastic film was removed from the membrane by peeling it off. The electrically conductive structures produced on the membrane exhibited the dimensions of the electrically conductive structures in the design with only minor deviations.

[0058] Figure 2 illustrates an advantage of the membrane produced by the process, which features nanopores N extending through its thickness. The microscopic image shows, in the lower half, nanopores N whose cross-sectional openings terminate in a dark area of ​​the membrane surface M, which was covered by a plastic film during gold sputtering. The upper half shows the sputtered gold conductive track E as a bright area. The image demonstrates that the process generates a high-density electrically conductive structure E, and that this structure exhibits a sharp boundary with the area covered by the plastic film. This allows for the fabrication of high-resolution, small-dimensional electrically conductive structures on the membrane.Furthermore, the image shows that the nanopores N are not covered in the area where the electrically conductive structure E is sputtered, but rather the cross-sectional openings in the electrically conductive structure E are open and accessible, and the electrically conductive structure is arranged along the cross-sectional openings of the pores without covering the cross-sectional openings.

[0059] Example 2: Impedance measurement of animal cells cultured on a membrane. A membrane 3 prepared according to Example 1 was placed, either without further coating or after coating with fibronectin, between chamber plates 2 made of double-sided adhesive plastic film, which were covered by glass plates or plastic film as cover plates 1, to create measurement chambers. The chambers formed by recesses in the chamber plates adjacent to the membrane on both sides in the region of the electrodes were filled with cell culture medium through corresponding holes in the cover plates. The chambers adjacent to a surface of the membrane were filled with medium containing human primary umbilical cord endothelial cells as an example of animal cells. Chambers with a membrane coated with fibronectin were loaded with 150,000 cells or 75,000 cells, while chambers without a fibronectin-coated membrane were loaded with 75,000 cells.The opposing chambers were filled with cell-free medium. The terminals of the electrically conductive structures were connected to an impedance measurement device. The measurement was performed at frequencies from 0 to 20 kHz at 5 mV.

[0060] Figure 3A shows Nyquist plots of impedance measurements during the first 28 h of cultivation for 150,000 cells on a fibronectin-coated membrane at 0 h (0), after 1:30 h (1.5 h), after 5 h (5 h), after 23 h (23 h), or after 28 h (28 h), and as a control, medium without cells (C). The measured values, based on the semicircular curve, show that after 5 h of cultivation the cells had grown confluently. Subsequently, this cell layer collapsed due to nutrient deficiency, which is evident from the measured values ​​shifting back to the left in the plot.

[0061] Figure 3B shows the Nyquist diagrams recorded during cultivation under cell culture conditions after the introduction of 150,000 cells into a fibronectin-coated membrane (150F), after the introduction of 75,000 cells into a fibronectin-coated membrane (75F), or after the introduction of 75,000 cells into a membrane without a fibronectin coating (75). The extent of the shift in the real part of the diagram over approximately 180, 250, and 310 mQ, respectively, is due to the length of the connecting tabs and leads.

[0062] This example shows that the membrane, a measuring chamber therewith and a method for measuring are suitable for determining the adhesion of cells to form a cell barrier on the membrane and its breakdown, and also shows that the application of the adhesive plastic film did not significantly impair the suitability of the membrane 3 with conductor tracks 4 produced according to the invention for adherent cell growth.

[0063] Examples of roll-to-roll processes for manufacturing the membrane with conductive structures on it are shown in Fig. 4 to Fig. 6, and in Fig. 7 a roll-to-roll process for manufacturing measuring chambers containing the membrane with conductive structures on it.

[0064] Figure 4 shows a system for a process in which a plastic film K, while resting on a carrier T, is provided with openings D according to a design for conductive structures by means of laser irradiation 12, and a membrane M, supplied from a roll 9, onto which a plastic film K, resting on a carrier T and supplied from a supply roll 13, is continuously applied. Openings D are created in the plastic film K by means of laser irradiation 12 according to a design for electrically conductive structures. Subsequently, the plastic film K is peeled from the carrier T and applied to the membrane M without the carrier T. In a magnetron sputtering system 11, conductive material is applied to the surface of the membrane M covered by the plastic film K. The membrane M, with the plastic film K applied to it, can be wound onto a pulley 15.

[0065] Figure 5 shows an embodiment in which the plastic film K, with perforations D according to the plan for electrically conductive structures, rests on the membrane M, and the membrane is wound onto a roll 15. The plastic film K, resting on the membrane M, is moved from the roll 15 between the target 19 made of conductive material and a roll 16 of a sputtering unit 11. After the conductive material is applied to the surface of the membrane M covered by the plastic film K, the film is wound onto a roll 22. The roll 16 and / or tension rollers 10, which tension the membrane M covered with the plastic film K against the roll 16, can form a counter-pole to the target 19. The sputtering unit 11 can include a sheet metal plate 17, arranged at a distance and parallel to the roll 16 and subjected to voltage, as an acceleration device.

[0066] The system shown in Fig. 5 preferably comprises a vacuum-sealed housing 18 in which the roller 15, from which the membrane M covered with the plastic film K is fed to the sputtering system, the sputtering system, and a roller 22, onto which the surface of the membrane M covered with the plastic film K is wound after application of the conductive material, are arranged. The method described thus can be carried out in a vacuum-sealed housing 18 that includes the roller 15, from which the membrane M covered with the plastic film K is fed to the sputtering system, the sputtering system, and a tension roller 22, onto which the surface of the membrane M covered with the plastic film K is wound after application of the conductive material E.

[0067] Fig. 6 shows a system for a roll-to-roll process according to the invention for producing a membrane 3 according to the invention, which has an electrically conductive structure E with at least two conductive tracks 4 on the membrane M. A plastic film K, which rests on a carrier T, is unwound from a supply roll 13. The plastic film is provided with perforations D by means of laser radiation 12 while it rests on a carrier T. Membrane M is unwound from a supply roll 9 and brought into contact with the plastic film K provided with perforations D, so that the plastic film K adheres to the membrane M while resting on the carrier T. The surface of the plastic film K facing the membrane M can have an adhesive layer H. Due to the adhesion of the plastic film K to the membrane M, the carrier T can be wound onto a pulley 24 and peeled off the plastic film K.The membrane M, with the preferably adhesive plastic film K attached to it, is moved through a sputtering unit 11 and sputtered with electrically conductive material on the surface covered with the plastic film. The sputtered plastic film K is peeled off the membrane M by means of a pulley 20, and the membrane M, sputtered with an electrically conductive structure E, is wound up by a pulley 32.

[0068] In accordance with the method, Fig. 6 shows a device configured for carrying it out, comprising a supply roll 13 for plastic film K, which rests on a carrier T, and a pull roller 24, which is configured for winding the carrier after it has been removed from the plastic film K adhering to the membrane M, the path of which extends between this supply roll 13 and the pull roller 24. A supply roll 9 for the membrane M provides the membrane M, which is wound onto a pull roller 32 at the end of the membrane's path. A laser 12 is arranged in the path of the carrier T, with which areas are removed from the plastic film according to a plan for electrically conductive structures by means of laser radiation, while the plastic film K rests on the carrier T. Preferably, the laser 12 is configured for ablating the areas to be removed.A supply roll 9 for membrane M provides the membrane M, the path of which extends from its supply roll 9 to a pull roller 32, which is configured to wind up the membrane after sputtering and removal of the plastic film. In the path of the carrier between the laser 12 and the pull roller 32 for the membrane, a device 28 for applying the plastic film K to the membrane M is arranged, and in the path of the carrier downstream of this device 28, a section 29 is arranged which is configured for removing the carrier from the plastic film, so that the membrane is covered by the plastic film and is only accessible for subsequent sputtering through the areas removed from the plastic film.Between the section 29 for peeling off the carrier and the pull roller 32 for the membrane, a sputtering unit 11 is arranged in the path of the membrane, and between the sputtering unit 11 and the pull roller 32, a section 31 for peeling the plastic film K from the membrane is arranged, the plastic film being wound onto a pull roller 20. The path of the plastic film extends from the supply roll 13 for plastic film K, which rests on a carrier T, to the pull roller 20, onto which the plastic film is wound after passing through the sputtering unit 11.

[0069] The device can be configured to place the perforated plastic film onto the membrane and to wind the membrane, with the plastic film on it, onto a pulley, which then forms a supply roll 15a. This can be achieved, for example, by means of a pulley arranged in the path of the carrier between the placement device 28 and the pulley 32 for the membrane, which then forms a supply roll 15a for the membrane covered by the perforated plastic film. The device can also be configured to unwind the membrane covered by the perforated plastic film from this supply roll (15a) and then wind it onto a pulley 22, with a sputtering unit 11 arranged in the path of the membrane.In this arrangement, a pull roller (22) can be arranged in the path of the membrane between the sputtering system (11) and the area (29) which is set up for peeling the carrier from the plastic film, which is set up to wind up the surface of the membrane covered with the plastic film, wherein this pull roller (22) forms a supply roller (15) for membrane (M) sputtered with conductive material E and covered by the plastic film K.

[0070] Figure 7 shows a method that can be used, for example, in conjunction with the method described in Figures 4, 5, or 6. A supply roll 15, on which the membrane M, sputtered with conductive material E and covered by the plastic film K, is provided, is unwound, and the plastic film K is peeled from the membrane M by means of a roll 20 onto which the plastic film K is wound. Subsequently, the membrane M, on which the electrically conductive structures E are arranged, is covered on both surfaces with a strip-shaped material 25 for chamber plates 2. The strip-shaped material 25 can, for example, be a double-sided adhesive plastic film. The strip-shaped material can, for example, be provided by supply rolls 26 for the strip-shaped material 25, wherein the strip-shaped material 25 lies on a carrier that is optionally wound up by means of a pull roller 33 and separated from the strip-shaped material 25.At least one of the ribbon-shaped materials 25, preferably both, has recesses 6, which were created, for example, by a structuring device or cutting device 27 as the material 25 passed through it. Such a structuring device or cutting device 27 can be a laser, an etching device, or a punching device. Preferably, the membrane M with the ribbon-shaped material 25 applied to both sides for chamber plates 2 is joined over its entire surface in a joining device 14a, for example, by gluing or bonding. Subsequently, the arrangement consisting of the membrane M with the ribbon-shaped material 25 applied to both sides is covered on both free surfaces of the ribbon-shaped material 25, which are opposite the membrane M, with ribbon-shaped material 30 for cover plates 1, preferably by gluing or bonding over its entire surface, for example, by means of a joining device 14b.From the strip-shaped arrangement thus produced, individual sections can be separated before winding onto a pulley 32 by means of a structure or device 27, which can be a separating device, e.g., cut out by means of laser radiation or punched out, in order to produce separate measuring chambers, preferably separate arrangements of at least two, e.g., 96 measuring chambers. The strip-shaped material 25 for chamber plates 2 can be provided on a carrier T and unwound from supply rolls 26, wherein the carrier T is pulled off the strip-shaped material 25 by a pulley 33 before the strip-shaped material 25 is applied to the membrane M.The strip-shaped material 30 for cover plates 1 can be provided on a carrier T and unwound from supply rolls 34, the carrier T being pulled away from the strip-shaped material 30 by a pull roller 35 before the strip-shaped material 30 is applied to the free surfaces of the strip-shaped material 25 for chamber plates 2. Reference numeral:

[0071] M Membrane 17 Sheet metal as acceleration device

[0072] N nanopores 18 housing

[0073] H Adhesive layer 19 Target

[0074] D Perforation 20 Pull roller for plastic film according to

[0075] K Plastic film splashing

[0076] T Carrier 21a Voltage source

[0077] E electrically conductive structure 21b earthing electrode H adhesive layer 22 pulley, on which, according to orders of the

[0078] 1 Cover plate made of conductive material E which is connected to the

[0079] 2-chamber plate plastic film covered surface of the

[0080] 3 Membrane produced according to the invention is wound up

[0081] 4 conductor track 24 pulley for carrier T

[0082] 5 measuring device 25 strip-shaped material for

[0083] 6 recesses chamber plates

[0084] 7 Connecting flag 26 Supply roll for strip-shaped material

[0085] 8 holes for chamber plate

[0086] 9 Supply roll for membrane 27 Structuring device,

[0087] 10 Tension roller separating device

[0088] 11 Sputtering system 28 Laying device

[0089] 12 Laser, laser irradiation 13 Supply roll 29 Area for peeling off the carrier 14a Connecting device 30 Strip-shaped material for cover plates

[0090] 14b Connection device 31 Area for pulling off the

[0091] 15 Supply roll for membrane material E sputtered with conductive plastic film and covered by the 32 pull roll for membrane plastic film K 33 Pull roll for ribbon material 15a Supply roll for membrane covered by the 34 Supply roll for ribbon material plastic film with perforations for cover plates 35 Pull roll for carrier of the ribbon

[0092] 16 Roll of a sputtering system, materials for cover plates

Claims

Claims 1. A method for producing electrically conductive structures (E) on a membrane (M) comprising the steps of: a) providing a plastic film (F), b) providing a plan for electrically conductive structures (E), c) removing areas from the plastic film (F) in which electrically conductive structures (E) are arranged according to the plan, wherein the plastic film (F) rests on a support (T) during the removal of areas to produce a plastic film (F) with perforations according to the electrically conductive structures (E) of the plan, d) placing the plastic film (F) with the perforations, while resting on the support (T), onto the membrane (M) such that the plastic film (F) adheres to the membrane (M) and the support (T) is removed from the plastic film (F) after the plastic film (F) has adhered to the membrane (M), e) sputtering electrically conductive material onto the plastic film (F).to apply conductive material to the plastic film (F) and through its perforations to the membrane (M), f) peeling the plastic film (F) from the membrane (M) to produce the membrane (M) with electrically conductive structures (E) attached to it.

2. Method according to claim 1, characterized in that the plastic film (F) has at least one adhesive surface and adheres to the membrane (M) by means of adhesive bonding.

3. Method according to one of the preceding claims, characterized in that the carrier (T) is removed from the plastic film (F) after the plastic film (F) has adhered to the membrane (M).

4. Method according to claim 1 or 2, characterized in that the plastic film (F) rests on a carrier (T) when removing areas in step c), and that after step c) the plastic film (F) with perforations is removed from the carrier (T) and subsequently placed on the membrane (M).

5. Method according to one of the preceding claims, characterized in that the plastic film (F) is placed on a carrier (T) in step a) and either areas of the plastic film (F) are removed in step c) by means of local planar laser ablation of the plastic film (F) or the openings to be created are completely separated as parts along their outline by laser irradiation along the contours, and then the plastic film (F) is peeled off the carrier (T) without the parts.

6. Method according to one of the preceding claims, characterized in that the plastic film (F) is surface-activated by contact with a plasma before sputtering in step e).

7. Method according to one of the preceding claims, characterized in that the plastic film (K) is provided from a supply roll (13) resting on a carrier (T), 8. Method according to one of the preceding claims, characterized in that the sequence of steps a) to f) is repeated at least twice.

9. Method according to one of the preceding claims, characterized in that the conductive material is a metal, in particular gold, platinum, silver, titanium, copper or a conductive carbon or titanium nitride or a conductive metal oxide, which is sputtered directly onto the membrane (M) covered by the plastic film with its perforations, so that the electrically conductive structures (E) lie directly on the membrane (M).

10. Method according to one of the preceding claims, characterized in that the membrane (M) has pores (N) that cross its thickness.

11. Method according to one of the preceding claims, characterized in that the electrically conductive structures (E) form at least one conductor track, at least one sensor surface and / or at least one electrode.

12. Method according to one of the preceding claims, characterized in that the membrane (M) with electrically conductive structures (E) fixed thereto is arranged between two chamber plates (2), each of which has recesses (6) forming chambers (6) adjacent to the membrane (M), and the chamber plates (2) are each covered opposite the membrane (M) by cover plates (1) which close off the chambers opposite the membrane (M), wherein the cover plates (1) have bores (8) which form access lines opening into the recesses (6) of the chamber plates (2) and have connections.

13. Method according to one of the preceding claims, characterized in that the membrane (M) with electrically conductive structures (E) attached thereto is connected as a base to an insert which is arranged in a dish and forms a chamber suitable for the cultivation of prokaryotic and eukaryotic cells.

14. Method according to claim 11 or 12, wherein prokaryotic and / or eukaryotic cells are cultured in chambers (6) formed on a membrane surface on which at least two electrically conductive structures (E) are arranged, while the electrically conductive structures (E) are subjected to a voltage of a frequency of up to 1 GHz for impedance measurement.

15. Membrane (M) obtained according to a method according to one of claims 1 to 12, which has pores (N) extending through its thickness and at least two electrically conductive structures (E) on one of its surfaces, characterized in that the electrically conductive structures (E) are arranged along cross-sectional openings of the pores (N) without covering the cross-sectional openings.

16. Measuring chamber, obtainable according to a method according to one of claims 11 to 12, comprising a membrane (M) according to claim 14, which is arranged between chamber plates (2), each of which has recesses (6) forming chambers (6) adjacent to the membrane (M), and the chamber plates (2) are each covered opposite the membrane (M) by cover plates (1) which close off the chambers (6) opposite the membrane (M), wherein the membrane (M) is made of plastic, has pores (N) extending through the thickness of the membrane (M), and at least the Chamber plates (2) and / or the cover plates (1) are made independently of each other of glass or silicon.

17. Device for producing a membrane, which has at least two electrically conductive structures on one of its surfaces, comprising a supply roll (13) for plastic film arranged on a carrier, a pull roller (24) configured to wind up the carrier at the end of its path, the path of the carrier extending between this supply roll (13) and this pull roller (24), a supply roll (9) for membrane, a pull roller (32) for the membrane configured to wind up the membrane at the end of its path extending from the supply roll (9) to the pull roller (32), a laser (12) in the path of the carrier, which is controlled for removing areas from the plastic film by laser irradiation of the plastic film according to a plan for electrically conductive structures while the plastic film is arranged on the carrier, and a device (28) for placing the membrane arranged in the path of the carrier between the laser (12) and the pull roller (32).which is configured for placing the plastic film onto the membrane, a section (29) arranged in the path of the carrier between the device for placing the plastic film onto the membrane and the pull roller (32) for the membrane, which is configured for peeling the carrier from the plastic film, and a sputtering unit (11) arranged in the path of the membrane between the section (29) which is configured for peeling the carrier from the plastic film and the pull roller (32) for the membrane, which is configured to apply electrically conductive material to the plastic film lying on the membrane.

18. Device according to claim 17, characterized by a supply roller (15a) for membrane (M) covered by the plastic film (K) with perforations, arranged in the path of the carrier (T) between the device for placing (28) and the pull roller (32) for the membrane (M).

19. Device according to one of claims 17 to 18, characterized by a pull roller (22) arranged in the path of the membrane between the sputtering unit (11) and the area (29) which is set up for peeling the carrier (T) from the plastic film (K), which is set up to wind up the membrane (M) covered with the plastic film (K), wherein this pull roller (22) forms a supply roller (15) for membrane (M) sputtered with conductive material and covered by the plastic film (K).

20. Device according to one of claims 17 to 19, characterized by a region (31) arranged in the path of the membrane between the sputtering system (11) and the pull roller (32) for the membrane, which is designed to pull the plastic film off the membrane, with a pull roller (20) for the plastic film.

21. Device according to one of claims 17 to 20, characterized by supply rolls (26) for strip-shaped material for chamber plates (25), a joining device (14a) that is configured for joining strip-shaped material for chamber plates (25) to both surfaces of a membrane (3) according to claim 14, supply rolls (34) for strip-shaped material for cover plates (1) and a joining device (14b) that is configured for joining strip-shaped material for cover plates (1) to the two free surfaces of the strip-shaped material for chamber plates (25).

22. Device according to one of claims 17 to 21, characterized by a structuring device (27) which is a separating device which is configured to separate sections from a band-shaped arrangement of a membrane (3) which is connected on both sides to band-shaped material for chamber plates (25) and resting thereon on both sides to band-shaped material for cover plates (1).

Images