DE102013222895A1 - Device for microfiltration of a fluid - Google Patents

Abstract

A device (1) for microfiltration of a fluid (2) with at least one microfilter unit is proposed, which microfilter unit (3) comprises a plurality of pores (5a, 5b, 5c) and through which the fluid (2) can flow, and at least one UV filter. Light source (4), wherein the microfilter unit (3) for sterilizing the pores (5a, 5b, 5c) with UV radiation of the UV light source (4) can be acted upon and the fluid (2) for sterilization with the UV radiation of the UV Light source (4) can be acted upon. It is essential that the UV light source (4) is designed as a UV LED element and the microfilter unit (3) has a waveguide region for UV radiation with a refractive index n ≥ 1.36, which waveguide region at least the pores (5a, 5b , 5c), wherein the UV LED element (4) and the microfilter unit (3) are arranged and configured in such a way that the UV radiation from the UV LED element (4) into the waveguide region of the microfiltration unit (3 ) is at least indirectly einkoppelbar.

Description

The invention relates to a device for microfiltration of a fluid according to the preamble of claim 1 and to a method for producing a device for microfiltration of a fluid according to the preamble of claim 12.

Such a device for microfiltration of a fluid comprises at least one microfilter unit with a plurality of pores, through which the fluid flows, and at least one UV light source, the microfilter unit for sterilizing the pores and the fluid for sterilization with UV radiation of the UV light source can be acted upon.

Devices of the type mentioned are typically used for the treatment of wastewater in sewage treatment plants or for the sterilization of drinking water. During degermination, organic residues, such as bacteria, viruses or amoebae, are killed by irradiation with UV light in the UVC range (wavelength range around 260 nm) by breaking up the nucleic bases of the DNA strand.

Large-volume devices with gas discharge lamps, for example mercury vapor lamps or amalgam lamps, which are arranged in a volume flow of the fluid for the admission of the fluid with UV radiation, are known from the prior art.

A disadvantage of the devices of the prior art is that the devices are large due to the high voltage required for the operation of the lamps and highly sensitive due to the use of the gas discharge lamps. For the reasons mentioned, these devices are also limited mobile use. It is also disadvantageous that in the previously known devices, a prefiltration must be carried out for the filtration of suspended matter or agglomerates.

The present invention is therefore based on the object to propose a device for microfiltration of a fluid, which allows a robust construction and allows the decentralized and / or mobile microfiltration of fluids.

This object is achieved by a device for microfiltration of a fluid according to claim 1 and by a method for producing a device for microfiltration of a fluid according to claim 12. Preferably embodiments of the device according to the invention can be found in claims 2 to 11. Preferably embodiments of the method according to the invention in the claims 13 to 15. Hereby, the wording of all claims is explicitly incorporated by reference into the description.

The device according to the invention for the microfiltration of a fluid comprises, as is known, at least one microfilter unit, which microfilter unit comprises a plurality of pores and through which the fluid can flow, and at least one UV light source. The microfilter unit can be acted upon for sterilizing the pores with UV radiation of the UV light source and the fluid is acted upon for sterilization with the UV radiation of the UV light source.

It is essential that the UV light source is designed as a UV LED element and the microfilter unit has a waveguide region for UV radiation with a refractive index n ≥ 1.36, which waveguide region comprises at least the pores, wherein the UV LED element and the microfilter unit are arranged and configured cooperatively in such a way that the UV radiation from the UV LED element can be at least indirectly coupled into the waveguiding region of the microfilter unit.

The invention is based on the Applicant's finding that the use of UV LED elements as a UV light source in combination with a guiding of the UV radiation in the waveguide region of the microfilter unit enables the construction of a compact and mobile device for the microfiltration of fluids.

This results in particular in the advantages that a lower operating voltage is required by the use of UV LEDs than in previously known UV light sources and the use of highly sensitive gas discharge lamps is avoided. It is also advantageous that by guiding the UV radiation in the microfiltration unit, the mechanical filtering of suspended matter and the UV sterilization of the fluid can take place in one step. The advantages mentioned have in common that they reduce the space requirement of the device for microfiltration of fluids and thus enable a compact and mobile design.

In the context of this description, a refractive index n ≥ 1.36 means that the real part of the refractive index, in particular in a UVC spectral range from 250 nm to 400 nm, is greater than or equal to 1.36. The refractive index of the waveguide region is thus significantly larger than the refractive index of the environment (typically air n≈1 or water), so that the guidance of the UV radiation in the waveguide region can be carried out by total reflection.

In the context of this description, sterilization of the pores of the microfilter unit also includes preventing or reducing the contamination of the pores.

In a preferred embodiment, the device comprises a plurality of UV LED Elements which are preferably arranged directly on the microfilter unit, so that the UV radiation from the UV LED elements is preferably coupled directly into the waveguide region of the microfilter unit. The UV LED elements are preferably arranged on the microfilter unit such that the UV radiation with a main radiation direction merges directly from the UV LED element into the waveguide region of the microfilter unit. The UV LED elements can be arranged at different locations of the microfilter unit. This has the advantage that the UV radiation can be efficiently coupled into the waveguide region of the microfilter unit. By providing a plurality of UV LED elements at different locations of the microfilter unit, sufficient UV radiation can be ensured in such a way that at least the surface of the pores, preferably the entire waveguide region, is penetrated by the UV radiation. Thus, at the interface between the fluid and the waveguiding region, also in the pores, an interaction between fluid and UV radiation takes place. This interaction is preferably also by an evanescent wave. For example, for sapphire (n = 1.84) as the material for the waveguide and water (n = 1.36), there is a penetration depth of the evanescent wave of UV radiation into the pores, depending on an angle of incidence, of approximately one wavelength. Especially with pores having a small pore diameter, the penetration depth of the evanescent wave is thus approximately in the region of the pore radius.

Preferably, the UV LED elements are circumferentially formed on an edge region of the microfilter unit. In this case, the UV LED elements may, for example, be arranged peripherally on the edge of the microfilter unit or arranged on a surface of the microfilter unit, preferably planar. When the UV LED elements are arranged on peripheral edges and / or in a peripheral edge region, the density of the UV LED elements is preferably between 0.1 and 10 UV LED elements / mm circumference.

As used herein, the term "UV LED element" refers to a UV LED or an array of multiple UV LEDs. The UV LEDs preferably emit UV radiation in a wavelength range of 250-280 nm.

A further preferred embodiment of the invention is characterized in that the UV-LED element is spatially separated from the fluid, in particular by the microfilter unit and / or by an additional waveguide element for the UV radiation. This has the advantage that contamination of the UV LED element is reliably avoided. In particular, it can be ensured by means of the additional waveguide element that the UV radiation is coupled via the waveguide element into the waveguide region of the microfiltration unit. In this case, the UV-LED element may preferably be arranged directly on the waveguide, so that the UV radiation from the UV-LED element enters the waveguide. The waveguide element and the microfilter unit are preferably arranged and configured to cooperate with one another such that the UV radiation from the waveguide element is coupled into the waveguide region of the microfilter unit.

In a further preferred embodiment, the device comprises an additional waveguide element for the UV radiation. The UV LED element is preferably arranged on the waveguide element in such a way that the UV radiation from the UV LED element can be coupled into the waveguide region of the microfilter unit via the waveguide element. The coupling of the UV radiation into the waveguide region of the microfilter unit takes place here indirectly via the waveguide element or via the waveguide element and the fluid. The additional waveguide element and the microfilter unit may preferably form a flow volume for the fluid to be filtered. This results in the advantage that an interaction and thus a UV sterilization of the fluid also takes place at an interface of the waveguide element and the fluid. It is also advantageous that flow chambers for the fluid to be filtered can be constructed in a simple and previously known manner by means of the waveguide element.

In a further preferred embodiment, the device has reflection means for the UV radiation. Particularly preferably, the reflection means are arranged on a side of the microfilter unit opposite the UV-LED element for reflection of the UV radiation. The reflection means can z. B. be formed as a reflective coating on an outer side of the microfilter and / or an outer side of the waveguide. Advantageously, the arrangement of reflection means for the UV radiation prevents the UV radiation in an angular range in which no total reflection occurs from the waveguide region of the microfiltration unit or the wave element exits and / or increases the repeated coupling of the UV radiation. Thus, in addition to the guidance of the UV radiation by total reflection, leakage of the UV radiation from the waveguiding region of the microfiltration unit or the wave element is reduced by reflection at the reflection means.

In a further preferred embodiment, the main emission direction of the UV LED element is perpendicular and / or parallel to a flow direction of the fluid.

Another preferred embodiment of the invention is characterized in that the microfilter unit is designed as a waveguide region.

Particularly preferably, the microfilter unit is formed from a material having a (real) refractive index n ≥ 1.36. Preferably, the microfilter unit is formed from the material of the waveguide region, in particular preferably in one piece. Preferably, the waveguide region comprises the microfilter unit. This has the advantage that the UV radiation can be guided in all areas of the microfiltration unit.

The waveguide region of the microfilter unit and / or the microfilter unit are preferably formed from quartz glass and / or sapphire. Both quartz glass and sapphire have optically high transmission in the UV spectral region and a (real) refractive index significantly greater than n = 1.36. Furthermore, the materials mentioned have an inert behavior towards aggressive media and a high resistance to corrosion and abrasion. In particular, when using sapphire there is the additional advantage that a large number of UV LEDs are produced on sapphire wafers as substrate material. As a result, the UV LED elements are already arranged in a simple and cost-effective manner on a sapphire substrate. This sapphire substrate with the UV LED elements can be used in a simple and cost-effective manner as a starting material for the microfilter unit.

In a further preferred embodiment, the device comprises at least two microfilter units, wherein the pores of a first microfilter unit have a larger diameter than the pores of a second microfilter unit subsequently arranged in the direction of flow of the fluid. Preferably, at least one UV LED element, most preferably at least two UV LED elements, are arranged on the first microfilter unit. The UV radiation is preferably coupled directly from the UV LED elements into the waveguiding region of the microfilter unit. A portion of the UV radiation is guided in the waveguide region of the first microfilter unit. Another part leaves the waveguide region of the first microfilter unit and is coupled via a waveguide element and / or the fluid into the waveguide region of the second microfilter unit.

The fluid first passes the first microfilter unit. The larger diameter pores substantially remove particulates and agglomerates. Due to the large diameter of suspended particles and agglomerates, there is the risk that the UV radiation does not completely penetrate them, so that sufficient disinfection with UV radiation is not ensured for the sterilization. Thus, the first microfilter unit preferably acts as a kind of pre-filter which eliminates suspended matter which may not fully penetrate the UV radiation. Germs entrapped therein could otherwise intact the microfiltration device. Furthermore, the pre-filter prevents the clogging of the fine pores of the downstream microfilter. Subsequently, the fluid passes through the second microfilter unit with the smaller pore diameter. Here, too, a filtration of smaller suspended matter and agglomerates and a UV sterilization takes place. The device thus preferably forms a multibarrier system with different pore size and selective UV irradiation. Here also microfilter units with a waveguide area and microfilter units without a waveguide area, i. H. purely for mechanical filtering, combined. It is also within the scope of the invention that an additional microfilter unit is designed as a purely mechanical pre-filter for removing suspended solids and substantially no UV sterilization takes place at this microfilter unit.

In a further preferred embodiment, the pores of the microfilter unit have a diameter in the range of 100 nm to 100 .mu.m, preferably in the range of 200 nm to 5 .mu.m, most preferably of about one micron. Preferably, the waveguiding region of the microfilter unit has between 30 k pores / mm ² and 150 k pores / mm ² , preferably between 60 k pores / mm ² and 120 k pores / mm ² , most preferably approximately 90 k pores / mm ² .

Another preferred embodiment of the invention is characterized in that the microfilter unit has a photocatalytic layer. Preferably, the photocatalytic layer is formed as a titanium dioxide layer. This enables a photocatalytic degermination at the interface of at least the waveguiding regions of the microfiltration unit and of the fluid. In photocatalytic sterilization, a catalyst (eg nanocrystalline titanium dioxide) decomposes under UV irradiation, preferably UVA radiation, organic molecules and bacteria. For example, titanium dioxide requires UV radiation in a wavelength range of about 385 nm. This has the advantage that powerful UVA LEDs based on GaInN semiconductors can be used in this wavelength range. These UVA LEDs are available with an efficiency of over 20%. Another advantage is that due to the wavelength range used cheaper waveguide materials, such as glass, glass fiber mats and / or UVA-transparent plastics, such as PMMA can be used. When using plastics results as an additional advantage that the pores of the Microfilter unit can be produced by simple and well-known impression techniques.

In a further preferred embodiment, the device comprises a power supply for the UV-LED element. By using UV LEDs, a DC low voltage supply is sufficient to operate the device. Preferably, the device is designed as a mobile device. The device can thus also in mobile applications, such. B. be used outdoors.

• A Bereitstellen eines UV-transparenten Substrats mit einem Brechungsindex n ≥ 1,36;
• B Definition der Poren in der Mikrofiltereinheit mittels Laserbearbeitung des Substrats;
• C Durchführen eines Ätzvorgangs,

dadurch gekennzeichnet, dass in Verfahrensschritt A die Weiterbearbeitung mittels eines Ultrakurzpulslasers derart erfolgt, dass das Substrat in Bereichen für die Poren in eine im Wesentlichen amorphe Phase umkristallisiert wird, und in dem Verfahrensschritt B mit dem Ätzvorgang selektiv amorphe Bereiche des Substrats entfernt werden.The object described above is furthermore achieved by a method according to claim 12. The method according to the invention for producing a device for microfiltration of a fluid comprises the following method steps:

• A providing a UV-transparent substrate having a refractive index n ≥ 1.36;
• B definition of the pores in the microfilter unit by means of laser processing of the substrate;
• C performing an etching process,

characterized in that in method step A, the further processing by means of a ultrashort pulse laser is carried out such that the substrate is recrystallized in areas for the pores in a substantially amorphous phase, and selectively removed in the process step B with the etching process amorphous regions of the substrate.

With this method can be advantageously produce fine, cylindrical and / or conical pores, which have a small diameter at a large longitudinal extent. The laser processing is carried out by means of a highly focused ultrashort pulse laser, z. B. with a wavelength of 355 nm and a pulse duration of 10 ps. The etching in process step C may, for. B. by means of hydrofluoric acid.

In a preferred embodiment of the method according to the invention, the pores have a diameter in the range of 100 nm to 100 μm, preferably in the range of 200 nm to 5 μm, most preferably of approximately one μm and a length in the range of 10 μm to 10 mm. preferably in the range of 10 μm to 1000 μm, most preferably in the range of 10 μm to 300 μm.

In a further preferred embodiment, a plurality of UV LEDs or a matrix of UV LEDs can be bonded to the microfilter unit, preferably the waveguide region of the microfilter unit and / or the waveguide element. This results in the advantage of direct light coupling without air gap and reflection losses.

The inventive method also has the aforementioned advantages of the device according to the invention.

The device according to the invention is preferably produced by means of the method according to the invention described above or a preferred embodiment of the method according to the invention. The method according to the invention is preferably designed to form a device according to the invention or a preferred embodiment thereof.

The apparatus and method of the invention are basically suitable for applications where fluids are to be filtered in compact, efficient, and robust microfiltration devices.

The inventive device and / or the inventive method are therefore preferably designed for mobile and decentralized water treatment, eg. B. in vehicles, development and crisis areas, or in the outdoor area. The microfiltration for water treatment can be carried out directly at the water tapping point or during use.

Further preferred features and embodiments of the device according to the invention and of the method according to the invention are explained below on the basis of exemplary embodiments and the figures. Showing:

1 a first embodiment of a device according to the invention for the microfiltration of fluids with a microfilter unit;

2 A second embodiment of a device according to the invention for the microfiltration of fluids with a microfilter unit;

3 A third embodiment of an inventive device for microfiltration of fluids with two microfiltration units;

4 A fourth embodiment of an inventive device for microfiltration of fluids in cross-flow technology with a microfilter and a waveguide.

In the 1 to 4 like reference characters designate the same or equivalent elements. All dimensions are to be understood as exemplary and do not include any limitation beyond the claims.

1 shows a schematic representation of a first embodiment of an inventive microfiltration of a fluid 2 , The contraption 1 includes a microfilter unit 3 and a plurality of UV LED elements, exemplified 4a . 4b , Typically, the density of the UV LED elements is between 0.1 and 10 UV LED elements / mm circumference. For reasons of better representability and clarity, only the two UV LED elements are used here, 4a . 4b shown. The UV LED elements 4a . 4b are planar, ie in one plane on the microfiltration unit 3 in an edge region of the microfiltration unit 3 appropriate. The edge region of the microfiltration unit is formed circumferentially. The device 1 includes a microfilter unit 3 with a waveguide region with a plurality of pores, characterized by way of example 5a . 5b . 5c , In the present case, the microfilter unit is designed such that the waveguide region covers the entire microfiltration unit 3 includes. The pores 5a . 5b . 5c have a diameter of about one micron and pass through the microfilter unit 3 , The microfilter unit 3 is formed of a UV-transparent material, in this case made of sapphire with a refractive index n = 1.83. Typically, the waveguiding area of the microfilter unit is approximately 90 k pores / mm ² . In the present case, only six pores are shown for reasons of better representability and clarity. The pores of the microfiltration unit 3 have a diameter of about 1 micron. The microfilter unit 3 in the present case has a longitudinal extent of 100 mm, a depth of approximately 100 mm and a thickness of 100 μm.

The flow direction of the fluid 2 runs in the drawing plane and is indicated by the two arrows. The flow direction of the fluid 2 is perpendicular to a longitudinal direction of the microfilter unit 3 ,

The exemplary UV LED elements 4a . 4b are each on the side of a surface of the microfilter unit 3 in the edge region of the microfiltration unit 3 arranged. This is a UV LED element 4a in an area in front of the first pore 5a on the microfilter unit 3 put on and the UV LED element 4b in the opposite area after the last pore on the microfilter unit 3 placed. Starting from the UV LED elements 4a . 4b the light goes into the microfilter unit 3 coupled, which acts as a waveguide. For better coupling of the UV light, the UV LED elements 4a . 4b opposite corner areas 6a . 6b the microfilter unit 3 be formed with a reflective coating. This will guide the UV radiation in the microfilter unit 3 improved.

The UV radiation is emitted by the UV LED elements 4a . 4b in the microfilter unit 3 coupled and due to total reflection at an interface between optically denser medium (waveguide region) and optically thinner medium (ambient air or fluid 2 ) guided in the microfilter unit. The UV radiation also interacts with the fluid 2 which the pores 5a . 5b . 5c the microfilter unit 3 flows through. Due to the small pore diameter, this interaction is also due to the evanescent wave at the interface between waveguide region and fluid 2 , By irradiation of the fluid 2 With the UV light, the sterilization of the fluid takes place 2 By killing the organic residues, such as bacteria, viruses, amoebae, etc. At the same time prevents the UV radiation germination and thus closure or clogging of the pores 5a . 5b . 5c whereby the need for a backwash (Backflush, a directed against the actual flow direction purging the pores 5a . 5b . 5c ) is reduced.

2 shows a schematic representation of a second embodiment of a device according to the invention 1 for microfiltration of a fluid 2 , To avoid repetition, the following is only to the differences to the 1 described device 1 for microfiltration of a fluid 2 received.

The UV LED elements 4a . 4b are here on the side of the edge of the microfilter unit 3 along the circumference of the microfilter unit 3 arranged. The coupling of the UV radiation takes place laterally directly into the microfiltration unit 3 , The main emission direction of the UV LED elements 4a . 4b is thus perpendicular to the flow direction of the fluid 2 , The UV LED elements can be removed from the fluid by planar seals 2 split off.

In the present case, the microfilter unit 3 be tapered so that a concentration of the light emitted by the UV-LED elements light in a central region of the pores 5a . 5b . 5c occurs in the waveguide region. In this case, the thickness of the waveguide element in the edge region can be 1-10 mm and in the central region of the pores 5a . 5b . 5c rejuvenate to 10-100 μm. This allows the coupling of larger housed UV LED elements with dimensions in the range of several mm. These can be arranged on the edge region and the light here in the waveguide region of the microfiltration unit 3 be coupled. By rejuvenating the microfiltration unit 3 the illumination density in the central area of the microfiltration unit increases 3 in which also the pores 5a . 5b . 5c are arranged.

3 shows a schematic representation of another embodiment of a device according to the invention 1 for microfiltration of a fluid 2 , To avoid repetition, the following is only to the differences to the 1 and 2 described device 1 for microfiltration of a fluid 2 received.

The device 1 includes a first microfilter unit 3a and a second microfilter unit 3b , The pores ( 5a.1 . 5b.1 . 5c.1 ) of the first microfilter unit 3a have a diameter of about 0.5-5 microns, in this case 5 microns. The pores ( 5a.2 . 5B.2 . 5c.2 ) of the second microfilter unit 3b have a diameter of about 1 micron. Thus, the pores ( 5a.2 . 5B.2 . 5c.2 ) of the second microfilter unit 3b , which is arranged downstream in the flow direction, a smaller diameter than the pores ( 5a.1 . 5b.1 . 5c.1 ) of the first microfilter unit 3a , Larger particles and agglomerates, which strongly absorb the UV radiation, thus already in the upstream first microfilter unit 3a filtered. In the microfilter unit 3b UV sterilization is then carried out without the risk that agglomerates, which are not penetrated by the UV radiation, in the fluid 2 remain. The reverse order is also conceivable: the pores of the second microfiltration unit 3b , which is arranged downstream in the flow direction, may also have a larger diameter than the pores of the first microfilter unit. The second microfilter unit 3b then serves only the UV sterilization by UV radiation.

The UV LED elements 4a . 4b are laterally along the periphery in the edge region on the first microfilter unit 3a placed. The coupling of the UV radiation into the first microfiltration unit 3a takes place directly from the UV LED elements 4a . 4b , The main emission direction of the UV LED elements 4a . 4b is parallel to the flow direction of the fluid 2 , It may be part of the UV radiation is in the first microfilter unit 3a while another part is the first microfilter unit 3a leaves and over the fluid 2 in the second microfilter unit 3b is coupled. The coupling of the UV radiation into the microfiltration unit 3b can thus indirectly via the microfilter unit 3a and the fluid 2 respectively. Here, too, the reverse order is conceivable: the coupling of the UV radiation and thus the UV sterilization can also take place exclusively or mainly in the downstream second microfilter unit.

The distance between the first microfilter unit 3a and the second microfilter unit 3b is 1 and 100 microns, in this case 100 microns. This ensures the necessary crossflow to the subsequent pores and improves the flow. The distance can be z. B. by a fiberglass grating, which between the first microfilter unit 3a and the second microfilter unit 3b is arranged. This increases the pressure resistance of the device.

4 shows a schematic representation of another embodiment of a device according to the invention 1 for microfiltration of a fluid 2 , To avoid repetition, the following is only to the differences to the 1 . 2 and 3 described device 1 for microfiltration of a fluid 2 received.

The device 1 comprises a waveguide element 7 , a microfilter unit 3 and a plurality of UV LED elements, exemplified 4a . 4b . 4c , The UV LED elements are present 2-dimensionally arranged. The distance between the UV LED elements can be between 0.5 and 20 mm, in the present case 10 mm. The UV LED elements 4a . 4b . 4c are on a side facing away from the fluid top of the waveguide 7 arranged. The waveguide element 7 is made of sapphire. This has the advantage that the waveguide 7 with the applied UV LED elements 4a . 4b . 4c can be formed in a conventional LED manufacturing process. UV LEDs are usually already formed during the manufacturing process on a sapphire substrate, so that such a sapphire substrate with UV LEDs arranged thereon in a simple and cost-effective manner as a waveguide 7 with UV LED elements 4a . 4b . 4c can be used.

From the waveguide element 7 spaced is the microfilter unit 3 arranged. The microfilter unit 3 includes a plurality of pores exemplified 5a . 5b . 5c , on. The pores 5a . 5b . 5c have a diameter of about one micron and may be cylindrical or conical. The distance between the waveguide element 7 and microfilter unit 3 is the distance of the UV LED elements 4a . 4b . 4c determined, preferably such that a homogenization of the UV illumination is achieved, and is 1-100 mm, preferably 10-2000 microns, most preferably 100 microns. The distance between the waveguide element 7 and microfilter unit 3 can be adjusted by a glass fiber grating or the like, which is between waveguide 7 and microfilter unit 3 is arranged. This increases the pressure resistance of the device.

The flow of the fluid 2 through the device 1 for microfiltration takes place, as indicated by the blue arrows, in cross-flow technology. The fluid 2 first the microfilter unit happens 3 through the pores 5a . 5b . 5c and then flows on the waveguide 7 along. However, the flow direction can also be reversed.

The UV LED elements 4a . 4b . 4c are on the fluid 2 facing away from the waveguide 7 placed. The coupling of the UV radiation into the waveguide 7 takes place directly from the UV LED elements 4a . 4b . 4c , Part of the UV radiation is in the waveguide 7 guided. Another part leaves the waveguide 7 and irradiates both the fluid 2 as well as the microfilter unit 3 , The coupling of the UV radiation into the microfiltration unit 3 thus takes place indirectly via the waveguide 7 and the fluid 2 ,

The manufacture of the device 1 for microfiltration of a fluid according to 4 can z. B. by wafer bonding of waveguide 7 and microfilter unit 3 , preferably in sandwich construction.

Claims (15)

Contraption ( 1 ) for the microfiltration of a fluid ( 2 ) with at least one microfilter unit, which microfilter unit ( 3 ) a plurality of pores ( 5a . 5b . 5c ) and of the fluid ( 2 ) and at least one UV light source ( 4 ), wherein the microfilter unit ( 3 ) for the sterilization of the pores ( 5a . 5b . 5c ) with UV radiation of the UV light source ( 4 ) is acted upon and the fluid ( 2 ) for sterilization with the UV radiation of the UV light source ( 4 ), characterized in that the UV light source ( 4 ) is designed as a UV LED element and the microfilter unit ( 3 ) has a waveguide region for UV radiation with a refractive index n ≥ 1.36, which waveguide region at least the pores ( 5a . 5b . 5c ), wherein the UV LED element ( 4 ) and the microfilter unit ( 3 ) are arranged and configured in such a way that the UV radiation from the UV LED element ( 4 ) into the waveguiding region of the microfiltration unit ( 3 ) is at least indirectly einkoppelbar. Contraption ( 1 ) according to claim 1, characterized in that the device ( 1 ) a plurality of UV LED elements ( 4a . 4b ), which preferably directly on the microfilter unit ( 3 ) are arranged so that the UV radiation from the UV LED elements ( 4a . 4b ) preferably directly into the waveguiding region of the microfiltration unit ( 3 ) can be coupled. Contraption ( 1 ) according to one of the preceding claims, characterized in that the UV LED element ( 4 ) of the fluid ( 2 ) is spatially separated, in particular by the microfilter unit ( 3 ) and / or by an additional waveguide element ( 7 ) for the UV radiation. Contraption ( 1 ) according to one of the preceding claims, characterized in that the device ( 1 ) an additional waveguide element ( 7 ) for the UV radiation, preferably that the UV LED element ( 4 ) on the waveguide element ( 7 ) is arranged such that the UV radiation from the UV LED element ( 4 ) via the waveguide element ( 7 ) into the waveguiding region of the microfiltration unit ( 3 ) can be coupled. Contraption ( 1 ) according to one of the preceding claims, characterized in that the device ( 1 ), In particular that the reflection means at a the UV-LED element ( 4a . 4b ) opposite side of the microfilter unit ( 3 ) are arranged for reflection of the UV radiation. Contraption ( 1 ) according to one of the preceding claims, characterized in that a main emission direction of the UV-LED element is perpendicular and / or parallel to a flow direction of the fluid. Contraption ( 1 ) according to one of the preceding claims, characterized in that the microfilter unit ( 3 ) is formed as a waveguide element, in particular of a material with a refractive index n ≥ 1.36, preferably of quartz glass and / or sapphire. Contraption ( 1 ) according to one of the preceding claims, characterized in that the device ( 1 ) at least two microfiltration units ( 3a . 3b ), wherein the pores ( 5a.1 . 5b.1 . 5c.1 ) a first microfilter unit ( 3a ) a larger diameter than the pores ( 5a.2 . 5B.2 . 5c.2 ) one in the direction of flow of the fluid ( 2 ) subsequently arranged second microfilter unit ( 3b ) exhibit. Contraption ( 1 ) according to one of the preceding claims, characterized in that the pores of the microfilter unit ( 3 ) have a diameter in the range of 100 nm to 100 μm, preferably in the range of 250 nm to 5 μm, most preferably about 1 μm. Contraption ( 1 ) according to one of the preceding claims, characterized in that the microfilter unit ( 3 ) has a photocatalytic layer, preferably a titanium dioxide layer. Contraption ( 1 ) according to one of the preceding claims, characterized in that the device ( 1 ) a power supply for the UV LED element ( 4 ), in particular, that the device ( 1 ) is designed as a mobile device. Method for producing a device ( 1 ) for the microfiltration of a fluid ( 2 ), which comprises the following method steps: A providing a UV-transparent substrate having a refractive index n ≥ 1.36 for a microfilter unit ( 3 ); B Definition of pores ( 5a . 5b . 5c ) of the microfilter unit ( 3 ) by means of laser processing of the substrate; C performing an etching process, characterized in that in method step A, the laser processing, preferably by means of a ps ultrashort pulse laser, takes place such that the substrate in areas for the pores ( 5a . 5b . 5c ) is recrystallized into a substantially amorphous phase, and in the method step B with the etching process selectively removed amorphous regions of the substrate. Method for producing a device ( 1 ) for the microfiltration of a fluid according to claim 12, characterized in that the pores ( 5a . 5b . 5c ) have a diameter in the range of 100 nm to 100 μm, preferably in the range of 250 nm to 5 μm, most preferably about one μm, and a length in the range of 10 μm to 10 mm, preferably in the range of 10 μm to 1 mm , most preferably in the range of 10 microns to 300 microns. Method for producing a device ( 1 ) for the microfiltration of a fluid according to claim 12 or 13, characterized in that the microfilter unit ( 3 ) in a method step D by means of wafer bonding on a waveguide element ( 7 ) is arranged. Method for producing a device ( 1 ) for the microfiltration of a fluid according to any one of claims 12 to 14, characterized in that in step A as the substrate a sapphire wafer with a plurality of UV LEDs ( 4a . 4b ) is used.

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