Cleaning cartridge for microfluidic device, microfluidic device and method for cleaning microfluidic device

Abstract

The invention relates to a cleaning cartridge (10) for a microfluidic device, comprising at least one cleaning element (21-23). According to the invention, the cleaning cartridge has at least one actuator (40) which is designed to move the cleaning elements (21-23). When cleaning a microfluidic device by means of a cleaning cartridge (10), the cleaning cartridge (10) is introduced into a receiving region of the microfluidic device such that at least one cleaning element (21-23) is positioned on at least one element of the microfluidic device to be cleaned, and then the cleaning element (21-23) is moved along the element to be cleaned by means of an actuator. The invention also relates to a microfluidic device which is designed to move at least one cleaning element (21-23) of a cleaning cartridge (10) along at least one element of the microfluidic device to be cleaned by means of at least one actuator (40) of the cleaning cartridge (10).

Description

Technical Field

[0001] The invention relates to a cleaning cartridge for a microfluidic device. The invention also relates to a method for cleaning a microfluidic device. Finally, the invention relates to a microfluidic device which is designed to be cleaned by means of a cleaning cartridge. Background Art

[0002] Microfluidic analysis devices can be operated by introducing a cartridge containing the sample to be detected and the chemical substance for reacting with the sample. These cartridges are designed as disposable parts and provide that all liquids are retained in the cartridge and do not come into contact with other parts of the analysis device. Nevertheless, due to leakage or damage to the cartridge, it may happen that the liquid is discharged from the cartridge and contaminates the parts of the analysis device. Then, the cleaning of the device can usually only be carried out by the manufacturer. Cleaning for maintenance purposes (for example, to remove dust deposits) cannot be carried out by the user either, but can only be carried out by the manufacturer when the analysis device is disassembled.

[0003] US10,828,675B2 describes a cleaning cartridge with which the components of a microfluidic analysis device can be cleaned. The cleaning cartridge has a cleaning pad, which the user must manually wet with a cleaning liquid. The cleaning cartridge is then introduced into the analysis device. The analysis device must be set up in advance for cleaning with the aid of such a cartridge. The components to be cleaned of the device are then guided along the cleaning pads in the cleaning program in order to clean the cleaning pads. Alternatively, the cleaning program may also be specified to move the entire cartridge in order to achieve cleaning of the components to be cleaned in this manner. Analysis devices that are not set up for cleaning with the aid of such a cleaning cartridge cannot be cleaned with it. Summary of the invention

[0004] The cleaning cartridge for a microfluidic device has at least one cleaning element. In addition, it has at least one actuator, which is set up to move the cleaning element relative to the element to be cleaned of the microfluidic device. Therefore, it is not necessary that the relative movement between the cleaning element and the element to be cleaned of the microfluidic device must be achieved by moving the element to be cleaned or by moving the entire cleaning cartridge. Instead, it is possible to move the cleaning element along the element to be cleaned by means of the actuator.

[0005] A microfluidic device implemented as an analytical device usually has a plurality of elements to be cleaned. Therefore, preferably, the cleaning cartridge has a plurality of cleaning elements. Particularly preferably, these cleaning elements are set up to be moved together by means of an actuator. Since the cleaning cartridge is provided for cleaning all elements to be cleaned in the analytical device (for which cleaning elements are actually present) by means of cleaning elements, a common movement of all cleaning elements can be provided. By causing this common movement by a common actuator, a structurally simple design of the cleaning cartridge can be achieved.

[0006] In addition, preferably, the cleaning tube has at least one cleaning element on a first side, and has at least one cleaning element on a second side opposite to the first side. When the microfluidic analysis device is set up for receiving the tube, the tube then usually has a fluid layer, a pneumatic layer and an elastomeric film arranged between the fluid layer and the pneumatic layer. The fluid layer is provided for conveying samples to be detected and other reagents and reacting them with each other. The pneumatic layer is provided for loading the elastomeric film with an overpressure or negative pressure by means of a pneumatic channel. By applying an overpressure, the elastomeric film is deflected into the fluid layer. By applying a negative pressure, the elastomeric film is deflected into the pneumatic layer. Thus, the fluid flow in the fluid layer can be manipulated. The first side of the cleaning tube is particularly provided for facing the first side of the receiving area for receiving the tube of the microfluidic device. The second side of the cleaning tube is particularly provided for facing the second side of the receiving area. The first side of the receiving area can particularly have a heating element, which is provided for the reagent in the fluid layer of the heating tube. In addition, the first side of the receiving area can particularly have an injection tappet, which is provided for ejecting reagents from the reagent strip in the fluid layer into the fluid channel system of the fluid layer. On the second side of the receiving area, a pneumatic manifold is arranged in particular, which is connected to the compressed air supply of the microfluidic device and is provided for establishing an underpressure or overpressure in the pneumatic channels of the pneumatic layer of the cartridge. The pneumatic manifold turns its seal toward the interior of the receiving area.

[0007] The cleaning element is in particular embodied as a nonwoven belt, a felt belt, a brush belt or a combination thereof. In particular, it can be provided that at least one cleaning element has different covering sections. In one embodiment, the belts can be embodied as single belts running around a roller. In another embodiment, the belts can be designed to be unwound, wherein, according to the cassette principle, the belt is unwound from one roller and simultaneously wound onto another roller during the use time. The cleaning element provided for cleaning the heater preferably has a brush length in the range of 0.1 mm to 0.5 mm. The cleaning element provided for cleaning the spray tappet kit also preferably has a brush length in the range of 0.1 mm to 0.5 mm. The cleaning element provided for cleaning the sealing gasket of the pneumatic manifold preferably has a brush length in the range of 0.5 mm to 2.0 mm. Therefore, the brush length (which is understood to be the length of the felt hair or the bristles) is respectively greater than the characteristic height of the element to be cleaned, but not so long as to impair the free mobility of the cleaning element.

[0008] In principle, it is possible that the user must wet the cleaning element with a cleaning fluid before using the cleaning cartridge. However, it is preferably provided that at least one storage container with a cleaning fluid is stored in the cleaning cartridge, which storage container is fluidically connected to the cleaning element. If the cleaning element is designed as a belt, it can be provided in particular that the cleaning element is in contact with the cleaning fluid during each operation. The cleaning fluid can be in particular isopropanol or petroleum ether.

[0009] If the cleaning cartridge is not designed as a disposable article but is intended for multiple use, it is further preferred that the cleaning cartridge has at least one collecting container for the contaminated cleaning fluid, which is fluidically connected to the cleaning element. The collecting container in particular has a scraping element for scraping the contaminated cleaning fluid and the dirt particles mixed therewith into the collecting container.

[0010] Preferably, the storage container of the reusable cleaning cartridge can be refilled and its collecting container can be emptied, so as to achieve a long service life of the cleaning cartridge. The cartridge is also particularly designed so that all functional elements themselves can also be easily cleaned.

[0011] If the cleaning cartridge is implemented as a disposable and a cleaning fluid is to be omitted, the cleaning element is preferably implemented so that dirt particles remain attached to the cleaning element. If only a storage container for the cleaning fluid is to be omitted, the cleaning element can be particularly soaked or moistened with the cleaning fluid.

[0012] The elements of the fluid layer of the microfluidic device facing the barrel are usually more polluted by the liquid discharged from the barrel than the pneumatic manifold. In addition, there are usually more sensitive components on the first side of the receiving area of ​​the microfluidic device than on the second side of the receiving area. When the cleaning barrel has cleaning elements on both sides, it is therefore preferred that the storage container with the cleaning fluid and the collection container for the contaminated cleaning fluid are only connected to the cleaning elements of the first side of the cleaning barrel, respectively, and not connected to the cleaning elements of the second side of the cleaning barrel. This embodiment variant also prevents particles from being transferred to other functional elements of the microfluidic device.

[0013] In one embodiment of the cleaning cartridge, the actuator is electrically driven. The cleaning cartridge has at least one electrical energy storage device, which is electrically connected to the actuator. In this way, the automatic operation of the cleaning cartridge can be achieved. If the cleaning cartridge is implemented as a reusable article, an interface can also be provided in order to recharge the energy storage device.

[0014] If the actuator is electrically driven, it can alternatively or additionally be provided that the cleaning cartridge has at least one interface which is electrically connected to the actuator and which is designed to be connected to the electrical energy source of the microfluidic device. This makes it possible to dispense with an electrical energy store in the cleaning cartridge. If an electrical energy store is still to be provided, it can be recharged by the electrical energy source of the microfluidic device. The electrical connection between the interface and the actuator can then be realized via the electrical energy store. In particular, the interface can be a USB interface.

[0015] In another embodiment of the cleaning tube, it is provided that the actuator is mechanically driven. For this purpose, the cleaning tube has at least one operating element, which is mechanically connected to the actuator. In this embodiment, the cleaning tube is implemented so long that the operating element remains accessible even when the cleaning tube is introduced into the microfluidic device. Then, the user can move the actuator by operating the operating element (for example, by rotational motion or circular motion or translational motion or linear motion).

[0016] In principle, the microfluidic device does not need to actively interact with the cleaning cylinder. However, it can be provided that the functions of the microfluidic device are activated during the cleaning process (for example, applying an overpressure or negative pressure) in order to support the cleaning process. In principle, these functions can be manually activated by the user. On the contrary, it is preferably provided that the cleaning cylinder has an identification element, which is set up to be read out by the microfluidic device. The readout can be performed when the cleaning cylinder is introduced into the microfluidic device, or it can also be performed before the introduction, in which the identification element is brought to the vicinity of the sensor arranged on the outside of the microfluidic device. By reading the identification element, the microfluidic device recognizes that the cleaning cylinder has been introduced into the microfluidic device and should start the function of supporting the cleaning process. In one embodiment of the cleaning cylinder, the identification element is a QR code. In another embodiment of the cleaning cylinder, the identification element is an RFID transponder.

[0017] Furthermore, it is preferred that the cleaning cartridge has at least one sensor. This sensor can be used to monitor the cleaning success. Furthermore, it can be used to check the element to be cleaned for defects. If the microfluidic device is designed to interact with the cleaning cartridge, it can also be provided that valves, switches or actuators in the receiving area of ​​the microfluidic device are controlled and their functional capacity is checked by means of the sensor. The results of this diagnosis can then be output by means of an interface on the microfluidic device.

[0018] The sensor can be, in particular, an optical sensor in order to enable diagnosis by means of imaging; it can be a temperature sensor in order to check the performance of a heating element of the microfluidic device; it can be a pressure sensor in order to check the functionality of a pneumatic manifold of the microfluidic device; or it can be a force sensor in order to monitor the pressing force of various components of the microfluidic device (e.g. a heating element or a pneumatic manifold) on the cleaning cartridge.

[0019] In a method for cleaning a microfluidic device by means of a cleaning cartridge, the cleaning cartridge is introduced into a receiving area of ​​the microfluidic device in such a way that at least one cleaning element is positioned on at least one element to be cleaned of the microfluidic device. The cleaning element is then moved along the element to be cleaned by means of an actuator. In particular, a change in the movement speed and / or the movement direction can be provided. The steps of the method are implemented in particular as a computer program in the microfluidic device in order to trigger an action of the microfluidic device and / or to control the cleaning cartridge via an interface in such a way that an action is triggered in the cleaning cartridge.

[0020] Preferably, during the method, a heating element of the microfluidic device and / or a compressed air supply are activated. The heating element is in particular actuated in such a way that a temperature which is above the ambient temperature in the receiving area, but of a maximum of 60° C., is generated on its surface facing the cleaning cylinder. As a result, scale deposits and deposits on the surface of the heating element can be dissolved more easily without triggering an undesired evaporation of the cleaning agent. The activation of the compressed air supply can be provided for blowing off sealing points or for preventing dirt particles from being transported into the actuation openings of the pneumatic manifold when cleaning the sealing gaskets of the pneumatic manifold.

[0021] Furthermore, it can be provided that a spray tappet of the microfluidic device is moved toward the cleaning cartridge in order to be able to clean it more easily.

[0022] If the cleaning cartridge has a sensor, then in the method the microfluidic device is preferably analyzed in the manner described in connection with the sensor.

[0023] The cleaning cartridge can in principle be used with a conventional microfluidic device, which is preferably configured to move at least one cleaning element of the cleaning cartridge along at least one element to be cleaned of the microfluidic device by means of an actuator of the cleaning cartridge. This can be achieved by controlling an electrically driven actuator via an interface between the cleaning cartridge and the microfluidic device.

[0024] In particular, the microfluidic device has a connection in its receiving region which is designed to be connected to a connection of the cleaning cartridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Exemplary embodiments of the invention are shown in the drawings and are described in more detail in the following description.

[0026] Figure 1 A first embodiment of a cleaning cartridge according to the invention is schematically shown.

[0027] Figure 2 Shows that the insertion is based on Figure 1 Cross-sectional view of the microfluidic device with a cleaning cartridge.

[0028] Figure 3 A flow chart of a method according to an embodiment of the present invention is shown.

[0029] Figure 4 A cleaning cartridge according to a second embodiment of the invention is schematically shown.

[0030] Figure 5 Shows that the insertion is based on Figure 4 Cross-sectional view of the microfluidic device with a cleaning cartridge.

[0031] Figure 6 The cleaning elements of one embodiment of a cleaning cartridge according to the invention are schematically shown.

[0032] Figure 7 A cleaning element of another embodiment of a cleaning cartridge according to the invention is schematically shown.

[0033] Figure 8 A side view of a strip of cleaning elements of a cleaning cartridge according to the invention is shown. DETAILED DESCRIPTION

[0034] Figure 1 , a cleaning cartridge 10 according to a first embodiment of the present invention is shown in FIG. The cleaning cartridge has an identification element 11 in the form of a QR code, by means of which the microfluidic device can identify the cleaning cartridge. The first cleaning element 21 arranged on the first side 12 of the cleaning cartridge 10 acting as the upper side is implemented as a felt belt, having a hair length of, for example, 200 μm. The first cleaning element has a storage container 31, which is filled with isopropanol as a cleaning fluid. In addition, the first cleaning element has a collection container 32 for contaminated cleaning fluid. The second cleaning element 22 is arranged on the second side 13 of the cleaning cartridge 10 acting as the lower side. The second cleaning element is implemented as a brush belt, having a brush length of, for example, 500 μm. The two cleaning elements 21, 22 are driven together by an actuator 40. When the first cleaning element 21 moves, the cleaning fluid is transported from the storage container 31 to the first cleaning element 21 and then received again by the collection container 32. The actuator 40 is driven by an electric drive 41. The electric drive is supplied with electrical energy from an electrical energy store 50 in the form of a battery via a first electrical connection 51. A second electrical connection 52 connects the energy store 50 to an interface 53. A third electrical connection 54 connects the electrical energy store 50 to an optical sensor 60.

[0035] Figure 2A microfluidic device 70 is shown in which a cleaning cartridge 10 is used for cleaning. The microfluidic device has a heating element 71, a pneumatic manifold 72 and a jet tappet set 73. The heating element 71 and the jet tappet set 73 are arranged on the upper side of the receiving area of ​​the microfluidic device 70. The pneumatic manifold 72 is arranged on its lower side. The cleaning cartridge 10 is arranged in the receiving area 74 so that its first side 12 points upward and its second side 13 points downward. Thus, the first cleaning element 21 is located at the heating element 71, and the second cleaning element 22 is located at the pneumatic manifold 72. The interface 53 is connected to an interface 75 of the microfluidic device, which is electrically connected to an electrical energy source (not shown) of the microfluidic device.

[0036] Figure 3 70 . After the user decides to clean the microfluidic device 70 at the start of the cleaning method 80 , the user first introduces the cleaning cartridge 10 into the receiving area 74 81 . The microfluidic device now recognizes that the cleaning cartridge 10 has been inserted into the microfluidic device 82 by reading the identification element 11 . Subsequently, the heating element 71 is activated 83 , in which the heating element is heated to a temperature of, for example, 50° C. and the pneumatic manifold 22 is activated, in which an overpressure of, for example, 0.2 bar is generated by means of its compressed air supply device. After the activation 83 is completed, a signal is sent to the cleaning cartridge 10 via the interface 53 , 75 to activate the electric drive 41 of the actuator 40 and thus start 84 the cleaning of the heating element 71 and the pneumatic manifold 72 . After the cleaning is completed by means of the sensor 60 , the electric drive 41 is turned off 85 . Next, the heating element 71 and the pneumatic manifold 72 are optically analyzed 86 for defects, for example, by means of the sensor 60 . The result of this analysis is output on the user interface of the microfluidic device 71. Next, the cleaning cartridge 10 is removed 87 from the receiving area 74 of the microfluidic device 70. This ends 88 the cleaning method.

[0037] Figure 4 , a second embodiment of the cleaning cartridge 10 is shown in FIG. The cleaning cartridge 10 according to the first embodiment is implemented as a reusable cartridge, which can interact with the microfluidic device 70 and its actuator 40 is electrically driven, while the cleaning cartridge 10 according to the second embodiment of the present invention is a mechanically driven disposable cartridge. Compared with the first embodiment, the identification element 11, the electric drive 41, the electric energy storage device 50, the interface 53, the sensor 60 and all the electrical connections 51, 52, 54 are omitted. In order to operate the actuator 40, a mechanical operating element 42 is provided, which is implemented as a drive wheel in the present embodiment. Since the cleaning cartridge 10 is only provided for disposable use, the collection container 32 is also omitted. The structural space thus obtained is used to arrange the third cleaning element 23 on the upper side of the cleaning cartridge 10. Like the first cleaning element 21, the third cleaning element has a storage container 31 with isopropyl alcohol as a cleaning liquid.

[0038] like Figure 5 , when the cleaning cartridge according to the second embodiment of the present invention is introduced into the microfluidic device 10, it protrudes slightly from the receiving area 74 of the microfluidic device 70, unlike the cleaning cartridge 10 according to the first embodiment of the present invention. Thus, the mechanical operating element 41 is accessible from the outside. The first cleaning element 21 and the second cleaning element 22 are located at the heating element 71 and the pneumatic manifold 72 of the microfluidic device 70, as in the cleaning cartridge according to the first embodiment of the present invention. The third cleaning element 23 is positioned at the injection tappet kit 73. If the user now turns the operating element 41, he will place the three cleaning elements 21, 22, 23 in motion by means of the actuator 40, so that the three cleaning elements clean the heating element 71, the pneumatic manifold 72 and the injection tappet kit 73 of the microfluidic device 70. Here, the first cleaning element 21 and the third cleaning element 23 are wetted by the cleaning fluid. After the cleaning is completed, the cleaning cartridge 10 is removed from the receiving area 74 of the microfluidic device 70 and then discarded.

[0039] In both embodiments of the present invention, the first cleaning element 21 can be implemented as a single belt (Einband). Figure 6 The belt 93 runs along the arrow direction around the first roller 91 and the second roller 92. The first roller 91 is driven by the actuator 40.

[0040] Alternatively, in both embodiments of the present invention, the first cleaning element 21 may be Figure 7 The belt 93 is unwound from the first roller 91 in the direction of the arrow and wound onto the second roller 92. The first roller 91 is driven by the actuator 40. In another embodiment, the belt 93 has a carrier 94 on which brush sections 95 and nonwoven sections 96 are alternately arranged. Figure 8 Shown in.

Claims

1. A cleaning cartridge (10) for a microfluidic device (70), the cleaning cartridge having at least one cleaning element (21-23), It is characterized in that The cleaning cartridge (10) has at least one actuator (40) which is configured to move the cleaning elements (21-23).

2. The cleaning cartridge (10) according to claim 1, It is characterized in that The cleaning elements (21-23) are implemented as nonwoven belts, felt belts, brush belts or a combination thereof.

3. The cleaning cartridge (10) according to claim 1 or 2, It is characterized in that The cleaning cylinder has a plurality of cleaning elements (21-23) which are configured to be moved together by means of an actuator (40).

4. The cleaning cartridge (10) according to any one of claims 1 to 3, It is characterized in that The cleaning cartridge has at least one cleaning element (21, 23) on a first side (12) and at least one cleaning element (22) on a second side (13) opposite the first side (12).

5. The cleaning cartridge (10) according to any one of claims 1 to 4, It is characterized in that At least one storage container (31) containing a cleaning fluid is stored in the cleaning cartridge and is fluidically connected to the cleaning elements (21-23).

6. The cleaning cartridge (10) according to claim 5, It is characterized in that The cleaning cartridge has at least one collecting container (32) for contaminated cleaning fluid, which is fluidically connected to the cleaning elements (21-23).

7. The cleaning cartridge (10) according to any one of claims 1 to 6, It is characterized in that The actuator (40) is electrically driven, and the cleaning cylinder (10) has at least one electrical energy storage device (50) which is electrically connected to the actuator (40).

8. The cleaning cartridge (10) according to any one of claims 1 to 7, It is characterized in that The actuator (40) is electrically driven, and the cleaning cartridge (10) has at least one interface (53) which is electrically connected to the actuator (40) and is designed to be connected to an electrical energy source of the microfluidic device (70).

9. The cleaning cartridge (70) according to any one of claims 1 to 6, It is characterized in that The actuator (40) is mechanically driven, and the cleaning cartridge (10) has at least one operating element (41) which is mechanically connected to the actuator (40).

10. The cleaning cartridge (10) according to any one of claims 1 to 9, It is characterized in that The cleaning cartridge has an identification element (11) which is designed to be read out by the microfluidic device (70).

11. The cleaning cartridge (10) according to any one of claims 1 to 10, It is characterized in that The cleaning cartridge has at least one sensor (60).

12. A method for cleaning a microfluidic device (70) by means of a cleaning cartridge (10) according to any one of claims 1 to 11, in, The cleaning cartridge (10) is introduced into a receiving area (74) of the microfluidic device (70) (81), so that at least one cleaning element (21-23) is positioned on at least one element (71-73) to be cleaned of the microfluidic device (70), and then the cleaning element (21-23) is moved along the element to be cleaned by means of the actuator (84).

13. The method according to claim 12, It is characterized in that During the method, a heating element (71) and / or a compressed air supply (72) of the microfluidic device (70) is activated (83).

14. The method according to claim 12 or 13, It is characterized in that The cleaning cartridge (10) is a cleaning cartridge (10) according to claim 10, and the microfluidic device (70) is analyzed (85) by means of the sensor (60).

15. A microfluidic device (70) configured to move at least one cleaning element (21-23) of a cleaning cartridge (10) according to any one of claims 1 to 11 along at least one element (71-73) to be cleaned of the microfluidic device (70) by means of at least one actuator (40) of the cleaning cartridge (10).

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