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

Abstract

The invention relates to a cleaning cartridge (10) for a microfluidic device, having at least one cleaning element (21 - 23). It has at least one actuator (40), which is designed to move the cleaning element (21 - 23). When the microfluidic device is being cleaned by means of the cleaning cartridge (10), the cleaning cartridge (10) is introduced into a receiving region of the microfluidic device in such a way that at least one cleaning element (21 - 23) is positioned on at least one element to be cleaned of the microfluidic device, and the cleaning element (21 - 23) is subsequently moved, by means of the actuator, along the element to be cleaned. The invention also relates to a microfluidic device which is designed so that, by means of at least one actuator (40) of the cleaning cartridge (10), it moves at least one cleaning element (21 - 23) of the cleaning cartridge (10) along on at least one element to be cleaned of the microfluidic device.

Description

[0001] Description

[0002] title

[0003] The present invention relates to a cleaning cartridge for a microfluidic device. Furthermore, the present invention relates to a method for cleaning the microfluidic device. Finally, the present invention relates to a microfluidic device configured to be cleaned using the cleaning cartridge.

[0004] State of the art

[0005] Microfluidic analysis devices can be operated by inserting a cartridge containing a sample to be analyzed and chemicals that react with the sample. These cartridges are designed as disposable components, and all fluids remain within the cartridge and do not come into contact with the components of the other analysis devices. Nevertheless, a leak or damage to the cartridge can cause fluids to escape from the cartridge and contaminate components of the analysis device. In this case, cleaning of the device can usually only be performed by the manufacturer. Even cleaning for maintenance purposes, for example to remove dust deposits, cannot be performed by the user; instead, the manufacturer must disassemble the analysis device.

[0006] US 10,828,675 B2 describes a cleaning cartridge with which components of a microfluidic analysis device can be cleaned. The cleaning cartridge has cleaning pads that must be manually saturated with a cleaning fluid by a user. The cleaning cartridge is then inserted into the analysis device. The analysis device must be configured in advance for cleaning using this cartridge. Components of the device to be cleaned are then moved along the cleaning pads in a cleaning program to clean them. Alternatively, the cleaning program can also provide for moving the entire cartridge in order to achieve cleaning of the components to be cleaned. An analysis device that is not configured for cleaning using this cleaning cartridge cannot be cleaned using it.

[0007] Disclosure of the invention

[0008] The cleaning cartridge for a microfluidic device comprises at least one cleaning element. It also comprises at least one actuator configured to move the cleaning element relative to an element of the microfluidic device to be cleaned. Thus, a relative movement between a cleaning element and an element of the microfluidic device to be cleaned does not require a movement of the element to be cleaned or a movement of the entire cleaning cartridge. Rather, the actuator allows the cleaning element to be moved along the element to be cleaned.

[0009] A microfluidic device designed as an analysis device typically has multiple elements to be cleaned. Therefore, it is preferred that the cleaning cartridge has multiple cleaning elements. These are particularly preferably configured to be moved jointly by means of an actuator. Since the cleaning cartridge is intended to clean all elements to be cleaned in the analysis device using cleaning elements for which cleaning elements are actually present, a joint movement of all cleaning elements can be provided. By causing this joint movement by a common actuator, it is possible to design the cleaning cartridge with a simple construction. Furthermore, it is preferred that the cleaning cartridge has at least one cleaning element on a first side and at least one cleaning element on a second side opposite the first side.If a microfluidic analysis device is designed to accommodate a cartridge, this cartridge typically comprises a fluidic layer, a pneumatic layer, and an elastomer membrane arranged between the fluidic layer and the pneumatic layer. The fluidic layer is designed to transport a sample to be analyzed and other reagents and to cause them to react with each other. The pneumatic layer is designed to apply positive or negative pressure to the elastomer membrane via pneumatic channels. By applying positive pressure, the elastomer membrane is deflected into the fluidic layer. By applying negative pressure, the elastomer membrane is deflected into the pneumatic layer. This allows fluid flows within the fluidic layer to be manipulated.The first side of the cleaning cartridge is particularly designed to face a first side of a receiving area of ​​the microfluidic device for receiving a cartridge. The second side of the cleaning cartridge is particularly designed to face a second side of the receiving area. The first side of the receiving area can particularly comprise a heating element designed to heat reagents in the fluidic layer of a cartridge. Furthermore, the first side of the receiving area can particularly comprise injection plungers designed to eject reagents from reagent bars in the fluidic layer into a fluid channel system of the fluidic layer.In particular, a pneumatic manifold is arranged on the second side of the receiving area. This manifold is connected to a compressed air supply of the microfluidic device and is designed to build up a negative or positive pressure in the pneumatic channels of the pneumatic layer of a cartridge. The pneumatic manifold faces its sealing mat toward the interior of the receiving area.

[0010] The cleaning elements are designed in particular as nonwoven belts, felt belts, brush belts or a combination of these. In particular, it can be provided that at least one cleaning element has different covering sections. In one embodiment, the belts can be designed as single belts running around rollers. In another embodiment, the belts can be designed to be unwinding, wherein according to a cassette principle, the belt is unwound from one roll and simultaneously wound onto the other roll over the period of use. A cleaning element which is provided for cleaning a heater preferably has a brush length in the range of 0.1 mm to 0.5 mm. A cleaning element which is provided for cleaning an injection tappet package likewise preferably has a brush length in the range of 0.1 mm to 0.5 mm.A cleaning element intended for cleaning a sealing mat of a pneumatic manifold preferably has a brush length in the range of 0.5 mm to 2.0 mm. Thus, the brush length, which refers to the length of the felt bristles or brush hairs, is greater than the characteristic height of the elements to be cleaned, without being so long that the free movement of the cleaning elements would be impaired.

[0011] In principle, it is possible for the cleaning elements to be moistened with a cleaning fluid by a user before using the cleaning cartridge. Preferably, however, the cleaning cartridge contains at least one reservoir containing a cleaning fluid, which is fluidically connected to the cleaning element. If the cleaning element is designed as a belt, it can be provided, in particular, that it is brought into contact with the cleaning fluid during each rotation. The cleaning fluid can be, in particular, isopropanol or petroleum ether.

[0012] If the cleaning cartridge is not designed as a disposable item but is intended for multiple use, it is further preferred that it has at least one collection container for contaminated cleaning fluid, which is fluidly connected to the cleaning element. The collection container, in particular, has a scraper element for scraping the contaminated cleaning fluid and any dirt particles mixed therewith into the collection container.

[0013] It is preferably provided that a storage container of a reusable cleaning cartridge is refillable and its collection container is emptied, thus enabling a long service life of the cleaning cartridge. Furthermore, the cartridge is designed in particular so that all functional elements themselves can also be easily cleaned.

[0014] If the cleaning cartridge is designed as a disposable item and a cleaning fluid is to be omitted, the cleaning element is preferably designed so that dirt particles adhere to it. If only the reservoir for the cleaning fluid is to be omitted, the cleaning element can be impregnated or wetted with cleaning fluid.

[0015] The elements of a microfluidic device facing the fluidic layer of a cartridge are typically more exposed to contamination by fluids escaping from the cartridge than the pneumatic manifold. Furthermore, more sensitive components are often located on the first side of the receiving area of ​​the microfluidic device than on the second side of the receiving area. Therefore, if the cleaning cartridge has cleaning elements on both sides, it is preferred that a reservoir containing a cleaning fluid and a collection container for contaminated cleaning fluid are each connected only to a cleaning element on the first side of the cleaning cartridge, but not to a cleaning element on the second side of the cleaning cartridge. This design variant also prevents the transfer of particles to other functional elements of the microfluidic device.

[0016] In one embodiment of the cleaning cartridge, the actuator is electrically driven. The cleaning cartridge has at least one electrical energy storage device that is electrically connected to the actuator. This enables automated operation of the cleaning cartridge. If the cleaning cartridge is designed as a reusable item, an interface can also be provided to recharge the energy storage device.

[0017] If the actuator is electrically driven, it can alternatively or additionally be provided that the cleaning cartridge has at least one interface that is electrically connected to the actuator and that is configured to be connected to an electrical energy source of the microfluidic device. This eliminates the need for an electrical energy storage device in the cleaning cartridge. If an electrical energy storage device is nevertheless to be provided, it can be recharged from the electrical energy source of the microfluidic device. The electrical connection between the interface and the actuator can then be established via the energy storage device. In particular, the interface can be a USB interface.

[0018] In a further embodiment of the cleaning cartridge, the actuator is mechanically driven. For this purpose, the cleaning cartridge has at least one actuating element that is mechanically connected to the actuator. In this embodiment, the cleaning cartridge is designed to be long enough that the actuating element remains accessible even when the cleaning cartridge is inserted into the microfluidic device. A user can then set the actuator in motion by actuating the actuating element, for example, by a rotary or circular movement or a translational or linear movement.

[0019] In principle, it is not necessary for the microfluidic device to actively interact with the cleaning cartridge. However, it can be provided that functions of the microfluidic device, such as the application of positive or negative pressure, are activated during the cleaning process to support the cleaning process. In principle, these functions could be initiated manually by a user. Preferably, however, it is provided that the cleaning cartridge has an identification element that is configured to be read by the microfluidic device. The reading can occur when the cleaning cartridge is inserted into the microfluidic device or also before insertion by bringing the identification element into proximity of a sensor arranged on an outer side of the microfluidic device.By reading the identification element, the microfluidic device recognizes that a cleaning cartridge has been inserted into it and that functions that support the cleaning process are to be initiated. In one embodiment of the cleaning cartridge, the identification element is a QR code. In another embodiment of the cleaning cartridge, the identification element is an RFID transponder.

[0020] Furthermore, it is preferred that the cleaning cartridge has at least one sensor. The sensor can be used to monitor the success of the cleaning process. Furthermore, it can be used to check elements to be cleaned for defects. If the microfluidic device is configured 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 functionality is checked using the sensor. The result of this diagnosis can then be output via an interface on the microfluidic device.

[0021] The sensor can in particular be an optical sensor to enable diagnosis by means of imaging, a temperature sensor to check the performance of a heating element of the microfluidic device, a pressure sensor to check the function of the pneumatic manifold of the microfluidic device, or a force sensor to monitor contact pressures of individual components of the microfluidic device, such as a heating element or the pneumatic manifold, against the cleaning cartridge.

[0022] In the method for cleaning the microfluidic device using the cleaning cartridge, the cleaning cartridge is inserted into a receiving area of ​​the microfluidic device such that at least one cleaning element is positioned on at least one element of the microfluidic device to be cleaned. The cleaning element is then moved along the element to be cleaned by means of the actuator. In particular, a change in the movement speed and / or direction of movement can be provided. Steps of the method are implemented in particular as a computer program in the microfluidic device in order to trigger actions of the microfluidic device and / or to control the cleaning cartridge via an interface such that actions are triggered therein.

[0023] It is preferred that a heating element and / or a compressed air supply of the microfluidic device be activated during the method. The heating element is, in particular, controlled such that a temperature is generated on its surface facing the cleaning cartridge that is higher than the ambient temperature in the receiving area, but not more than 60°C. This makes it easier to remove encrustations and deposits on the surface of the heating element without triggering undesired evaporation of a cleaning agent. Activating the compressed air supply can be intended to blow out sealing points or to prevent dirt particles from being transported into the control bores of the pneumatic manifold when cleaning a sealing mat of the pneumatic manifold.

[0024] Furthermore, it can be provided that injection plungers of the microfluidic device are moved towards the cleaning cartridge in order to make it easier to clean.

[0025] If the cleaning cartridge has a sensor, the method preferably involves analyzing the microfluidic device in the manner described in connection with the sensor.

[0026] While the cleaning cartridge can generally be used with a conventional microfluidic device, the microfluidic device is preferably configured to move at least one cleaning element of the cleaning cartridge along at least one element of the microfluidic device to be cleaned 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.

[0027] The microfluidic device has, in particular, an interface in its receiving area that is configured to be connected to an interface of the cleaning cartridge. Brief description of the drawings

[0028] Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description.

[0029] Fig. 1 shows schematically a first embodiment of a cleaning cartridge according to the invention.

[0030] Fig. 2 shows a sectional view of a microfluidic device in which the cleaning cartridge according to Fig. 1 is inserted.

[0031] Fig. 3 shows a flowchart of a method according to an embodiment of the invention.

[0032] Fig. 4 shows schematically a cleaning cartridge according to a second embodiment of the invention.

[0033] Fig. 5 shows a sectional view of a microfluidic device into which a cleaning cartridge according to Fig. 4 is inserted.

[0034] Fig. 6 shows schematically a cleaning element of an embodiment of a cleaning cartridge according to the invention.

[0035] Fig. 7 shows schematically a cleaning element of another embodiment of a cleaning cartridge according to the invention.

[0036] Fig. 8 shows a side view of a band of a cleaning element of a cleaning cartridge according to the invention.

[0037] Embodiments of the invention

[0038] A cleaning cartridge 10 according to a first embodiment of the invention is shown in Fig. 1. It has an identification element 11 in the form of a QR code, by means of which it can be identified by a microfluidic device. A first cleaning element 21, which is arranged on a first side 12 of the cleaning cartridge 10 acting as the upper side, is designed as a felt belt with a hair length of, for example, 200 μm. It has a reservoir 31 filled with isopropanol as the cleaning fluid. It also has a collection container 32 for contaminated cleaning fluid. A second cleaning element 22 is arranged on a second side 13 of the cleaning cartridge 10 acting as the underside. It is designed as a brush belt with a brush length of, for example, 500 μm. The two cleaning elements 21, 22 are jointly driven by an actuator 40.As the first cleaning element 21 moves, cleaning fluid is transported from the reservoir 31 to the first cleaning element 21 and then collected again by the collection container 32. The actuator 40 is driven by an electric drive 41. This is supplied with electrical energy by an electrical energy storage device 50 in the form of a battery via a first electrical connection 51. A second electrical connection 52 connects the energy storage device 50 to an interface 53. A third electrical connection 54 connects the electrical energy storage device 50 to an optical sensor 60.

[0039] Fig. 2 shows a microfluidic device 70 to be cleaned with the cleaning cartridge 10. It has a heating element 71, a pneumatic manifold 72, and an injection plunger assembly 73. The heating element 71 and the injection plunger assembly 73 are arranged on an upper side of a receiving area of ​​the microfluidic device 70. The pneumatic manifold 72 is arranged on its underside. The cleaning cartridge 10 is arranged in the receiving area 74 such that its first side 12 faces upward and its second side 13 faces downward. As a result, the first cleaning element 21 comes to rest on the heating element 71, and the second cleaning element 22 comes to rest on the pneumatic manifold 72. The interface 53 connects to an interface 75 of the microfluidic device, which is electrically connected to its electrical energy source (not shown).

[0040] The sequence of cleaning the microfluidic device 70 is shown in Fig. 3. After a user decides to clean the microfluidic device 70 at the start 80 of the cleaning process, he first inserts the cleaning cartridge 10 into the receiving area 74 81. The microfluidic device then recognizes by reading the identification element 11 that the cleaning cartridge 10 has been inserted into it 82. The heating element 71 is then activated 83 by heating it to a temperature of, for example, 50°C and the pneumatic manifold 22 is activated by generating an overpressure of, for example, 0.2 bar by means of its compressed air supply. After this activation 83 is completed, a signal is sent to the cleaning cartridge 10 via the interfaces 53, 75 to activate the electric drive 41 of the actuator 40 and thus initiate the cleaning of the heating element 71 and the pneumatic manifold 72 84.After the sensor 60 detects that cleaning is complete, the electric drive 41 is shut down 85. Subsequently, the sensor 60 performs, for example, an optical analysis 86 of the heating element 71 and the pneumatic manifold 72 for defects. The result of this analysis is displayed at a user interface of the microfluidic device 71. Subsequently, the cleaning cartridge 10 is removed 87 from the receiving area 74 of the microfluidic device 70. This concludes the cleaning process 88.

[0041] A second embodiment of the cleaning cartridge 10 is shown in Fig. 4. While the cleaning cartridge 10 according to the first embodiment is designed as a reusable cartridge that can interact with the microfluidic device 70 and whose actuator 40 is electrically driven, the cleaning cartridge 10 according to the second embodiment of the invention is a mechanically driven disposable cartridge. Compared to the first embodiment, the identification element 11, the electric drive 41, the electrical energy storage device 50, the interface 53, the sensor 60, and all electrical connections 51, 52, 54 are omitted. To actuate the actuator 40, a mechanical actuating element 42 is provided, which in the present embodiment is designed as a drive wheel. The collection container 32 is also omitted, since the cleaning cartridge 10 is intended for only one-time use.The resulting space is used to provide a third cleaning element 23 on the top of the cleaning cartridge 10. Just like the first cleaning element 21, this element has a reservoir 31 containing isopropanol as the cleaning fluid.

[0042] When the cleaning cartridge according to the second embodiment of the invention, as shown in Fig. 5, is inserted 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 invention. This makes the mechanical actuating element 41 accessible from the outside. The first cleaning element 21 and the second cleaning element 22 are located on the heating element 71 and the pneumatic manifold 72 of the microfluidic device 70, just as in the cleaning cartridge according to the first embodiment of the invention. The third cleaning element 23 is positioned on the injection plunger assembly 73.When a user rotates the actuating element 41, they move the three cleaning elements 21, 22, 23 via the actuator 40, so that they clean the heating element 71, the pneumatic manifold 72, and the injection plunger assembly 73 of the microfluidic device 70. The first cleaning element 21 and the third cleaning element 23 are wetted with cleaning fluid. After cleaning is complete, the cleaning cartridge 10 is removed from the receiving area 74 of the microfluidic device 70 and subsequently disposed of.

[0043] In both embodiments of the invention, the first cleaning element 21 can be designed as a belt. This is illustrated in Fig. 6. A belt 93 rotates in the direction of the arrow around a first roller 91 and a second roller 92. The first roller 91 is driven by the actuator 40.

[0044] Alternatively, the first cleaning element 21 in both embodiments of the invention can be designed as shown in Fig. 7. The belt 93 is unwound in the direction of the arrow from a first roll 91 and wound onto a second roll 92. The first roll 91 is driven by the actuator 40. In a further embodiment, the belt 93 has a carrier 94 on which a brush section 95 and a fleece section 96 are arranged alternately. This is shown in Fig. 8.

Claims

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

2. Cleaning cartridge (10) according to claim 1, characterized in that the cleaning element (21 - 23) is designed as a nonwoven belt, felt belt, brush belt or a combination of these.

3. Cleaning cartridge (10) according to claim 1 or 2, characterized in that it comprises a plurality of cleaning elements (21 - 23) which are arranged to be moved jointly by means of an actuator (40).

4. Cleaning cartridge (10) according to one of claims 1 to 3, characterized in that it 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. Cleaning cartridge (10) according to one of claims 1 to 4, characterized in that it contains at least one storage container (31) with a cleaning fluid, which is fluidically connected to the cleaning element (21 - 23).

6. Cleaning cartridge (10) according to claim 5, characterized in that it has at least one collecting container (32) for contaminated cleaning fluid, which is fluidly connected to the cleaning element (21 - 23). Cleaning cartridge (10) according to one of claims 1 to 6, characterized in that the actuator (40) is electrically driven and the cleaning cartridge (10) has at least one electrical energy storage device (50) that is electrically connected to the actuator (40). Cleaning cartridge (10) according to one of claims 1 to 7, characterized in that the actuator (40) is electrically driven and the cleaning cartridge (10) has at least one interface (53) that is electrically connected to the actuator (40) and that is configured to be connected to an electrical energy source of the microfluidic device (70). Cleaning cartridge (70) according to one of claims 1 to 6, characterized in that the actuator (40) is mechanically driven and the cleaning cartridge (10) has at least one actuating element (41) that is mechanically connected to the actuator (40).The cleaning cartridge (10) according to one of claims 1 to 9, characterized in that it comprises an identification element (11) configured to be read by the microfluidic device (70). The cleaning cartridge (10) according to one of claims 1 to 10, characterized in that it comprises at least one sensor (60). A method for cleaning a microfluidic device (70) using a cleaning cartridge (10) according to one of claims 1 to 11, wherein the cleaning cartridge (10) is inserted (81) into a receiving area (74) of the microfluidic device (70) such that at least one cleaning element (21-23) is positioned on at least one element (71-73) of the microfluidic device (70) to be cleaned, and the cleaning element (21-23) is subsequently moved (84) along the element to be cleaned by means of the actuator.

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

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

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

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