Microfluidic flow cell, and method for manufacturing a microfluidic flow cell

Abstract

The invention relates to a microfluidic flow cell comprising a storage device (1) that has a reservoir chamber (2) for a fluid and an outlet channel (3) for transporting fluid. According to the invention, a capture channel (4) is formed around the reservoir chamber (2) and is fluidically connected to the outlet channel (3). The capture channel (4) expediently surrounds part of the reservoir chamber (2) or completely encloses it. Preferably, the storage device (1) comprises a separation region (5) between the reservoir chamber (2) and the capture channel (4), which separation region can be opened to form a fluidic connection between the reservoir chamber (2) and the capture channel (4). In one embodiment of the invention, the storage device (1) has a predetermined breaking point (6; 11) for opening a preferably direct fluidic connection between the reservoir chamber (2) and the outlet channel (3) and / or a preferably direct fluidic connection between the reservoir chamber (2) and the capture channel (3). The invention also relates to a method for producing a microfluidic flow cell.

Description

[0001] Description:

[0002] Microfluidic flow cell and method for producing a microfluidic flow cell

[0003] The invention relates to a microfluidic flow cell with a storage device comprising a storage chamber for a fluid and a discharge channel for fluid transport, and to a method for producing a microfluidic flow cell.

[0004] WG2009 / 071078 A1 describes such a flow cell, which is used, for example, in the analysis of fluids (gases and liquids) in medical diagnostics and analytics, as well as environmental analysis. In addition to storage, the storage device serves the transport and / or targeted release of fluids. A problem is that when the storage chamber is activated, e.g., under the influence of force or heat, components of the flow cell can unintentionally separate from each other, and the fluid can escape from the fluid cell.

[0005] The invention is based on the object of creating a flow cell of the type mentioned above which is better protected against unintentional leakage of the fluid.

[0006] The flow cell according to the invention which solves this problem is characterized in that a collecting channel is formed around the storage chamber, which is in flow connection with the discharge channel.

[0007] The collection channel is designed to collect fluid that flows through an area between the storage chamber and the collection channel in the storage device when components of the storage device separate from each other. When the fluid flows from the storage chamber into the collection channel, it is transported from there via the discharge channel for further use. The resulting pressure relief prevents the components from further separating from each other, thus preventing unintentional fluid leakage from the flow cell.

[0008] The collecting channel can be provided, for example, to secure the storage device.

[0009] In one embodiment of the invention, the storage chamber can be directly connected to the discharge channel. As provided in a preferred embodiment of the invention, the storage device expediently has a predetermined breaking point for opening a, preferably direct, flow connection between the storage chamber and the discharge channel. The storage device is preferably provided such that the discharge channel predetermined breaking point opens under the influence of heat and / or upon the action of a mechanical force on the storage chamber, for example by means of a plunger of a device for actuating the storage device, under the resulting pressure of the fluid. The discharge channel predetermined breaking point can be arranged directly on the storage chamber, and the discharge channel leads away from the predetermined breaking point.

[0010] The fluid is preferably directed directly into the discharge channel via the predetermined break point. The collecting channel secures the flow cell if, particularly when the storage chamber is activated, the predetermined break point does not open, or only opens if it does, and if, as explained above, the components of the storage device unintentionally separate from each other. The escaping fluid is collected by the collecting channel and directed into the discharge channel. The storage device functions as intended even if the components separate without the fluid escaping from the storage device.

[0011] The aforementioned region can also be provided as a separating region between the storage chamber and the collecting channel, which can be selectively opened to create a flow connection between the storage chamber and the collecting channel, preferably forming a bridging channel. The fluid from the storage chamber is then directed into the discharge channel via the collecting channel exclusively by opening the separating region at least at one point. The predetermined breaking point described above for creating a direct connection between the storage chamber and the discharge channel is then not necessarily required.

[0012] The storage device expediently comprises a predetermined breaking point for opening a, preferably direct, flow connection between the storage chamber and the collecting channel. The discharge channel predetermined breaking point and / or the collecting channel predetermined breaking point can be formed by a bulge of an inner wall of the storage chamber towards the collecting channel and / or a bulge of an inner wall of the collecting channel towards the storage chamber and / or by a connection between components of the storage device that is deliberately weakened in certain sections. When a mechanical force acts on the storage chamber, the discharge channel predetermined breaking point and / or the collecting channel predetermined breaking point opens under the force of the fluid, and a flow connection is formed from the storage chamber to the collecting channel, in particular forming the bridging channel, and thus to the discharge channel.

[0013] In one embodiment of the invention, the flow cell, in particular the storage device, comprises a substrate and a cover layer attached to the substrate at least in sections, optionally in a fluid-tight manner. The storage device can be formed exclusively by the substrate and the cover layer. Conveniently, the storage device comprises only a single cover layer, which is preferably formed by a single film.

[0014] The storage chamber, the discharge channel, the collecting channel, and / or the bridging channel is / are preferably formed by a gap between the substrate and the cover layer, e.g., by a film or the like. The cover layer expediently forms at least one wall of the storage chamber, the discharge channel, the collecting channel, and / or the bridging channel.

[0015] In one embodiment of the invention, the cover layer and the substrate form the only walls of the storage chamber, the discharge channel, the collection channel and / or the bridging channel.

[0016] Advantageously, a wall section of the storage chamber, in which the storage chamber can be actuated mechanically or thermally, is formed by the cover layer.

[0017] The substrate and / or the cover layer, in particular the film, can, depending on the application, be made of plastic, e.g. PC, PMMA, COC or PS, or of aluminum. The substrate is preferably connected to the cover layer by gluing or welding. In particular, in the said region between the storage chamber and the collecting channel, in particular the said separating region, the cover layer is connected to the substrate in a fluid-tight manner. The cover layer, in particular the film, is expediently made of a flexible and / or deformable material. The cover layer is preferably flexible and / or deformable in such a way that, in order to actuate the storage chamber, mechanical force and / or heat can be applied to it while it is being deformed, and / or that the separating region between the storage chamber and the collecting channel can be opened, preferably to form the bridging channel.

[0018] It is advisable for the collecting channel to be in flow connection exclusively with the discharge channel, particularly as long as the area between the storage chamber and the collecting channel is closed.

[0019] In a particularly preferred embodiment of the invention, the collecting channel partially or completely surrounds the storage chamber. The collecting channel expediently surrounds at least two-thirds, preferably at least three-quarters, and particularly preferably at least five-sixths, of one lateral outer wall of the storage chamber.

[0020] Preferably, the storage chamber and the collecting channel are arranged such that the distance between the lateral outer wall and the side of the collecting channel facing the storage chamber, possibly with the exception of at least one predetermined breaking point in the collecting channel, is the same or at least almost the same across the circumference of the storage chamber. The collecting channel is expediently formed parallel or almost parallel to the lateral outer wall of the storage chamber.

[0021] The collecting channel is expediently annular, at least in sections. This proves particularly advantageous when the storage chamber, in particular its lateral outer wall, is circular or annular when viewed from above. If the collecting channel does not completely surround the storage chamber, a supply and / or discharge channel can be provided in an area where the collecting channel is not provided, which is preferably directly connected to the storage chamber, e.g., for filling or emptying and / or for de-aerating and / or ventilating the storage chamber.

[0022] In a further embodiment of the invention, the collecting channel and / or the drainage channel have channel walls that lie or can be placed against one another, at least one of which wall can be deformed by the fluid to form the collecting channel or the drainage channel. In particular, the wall can be stretched by the fluid to form the collecting channel or the drainage channel. Preferably, the channel walls are each formed by a flexible film or membrane or by a flexible film and a rigid plate. The drainage channel can comprise several sections, between which, for example, a container is arranged, and preferably leads to at least one further component of the flow cell. The component can be a measuring container or a container containing a reagent, in particular a dry reagent.

[0023] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings relating to these exemplary embodiments. They show:

[0024] Fig. 1 shows a first embodiment of a storage device of a flow cell according to the invention in various views,

[0025] Fig. 2 shows the storage device according to Fig. 1 in different views in a different position,

[0026] Fig. 3 to 5 further storage devices of flow cells according to the invention and Fig. 6 a flow cell according to the invention.

[0027] A storage device 1 of a flow cell according to the invention, which is shown in various views in Fig. 1, has a substrate 7, to which a cover layer 8 is attached in sections, which can consist, for example, of a film or a membrane. The cover layer 8 forms a wall 9 of a storage chamber 2 for receiving a fluid that can be processed by means of the flow cell. The cover layer 8 is connected to the substrate 7 in a fluid-tight manner around the storage chamber 2, for example by gluing or welding. As can be seen from the dashed lines, a drainage channel 3 is formed in the substrate 7, via which the fluid can be drained from the storage chamber 2 for further use in the flow cell.In order to establish a flow connection between the storage chamber 2 and the discharge channel 3, a predetermined breaking point 6 is provided in a connecting region 5 between the storage chamber 2 and the discharge channel 3, which opens when force is exerted on a wall 9 of the storage chamber 2 formed by the cover layer 8. By exerting such force, e.g. by means of a plunger of a device (not shown here) for actuating the storage device 1, the wall 9 of the storage chamber 2 is moved from the position shown in Fig. 1 b) to a position shown in Fig. 2 a), which shows the storage device 1 in section from the side. Due to the pressure exerted on the fluid, the cover layer 8 is detached from the substrate 7 in the separation region, the predetermined breaking point 6 breaks open, and the fluid can flow through the predetermined breaking point 6 from the storage chamber 2 into the discharge channel 3.

[0028] In the event that the predetermined breaking point 6 does not open as intended, but as shown in Fig. 2 c), under the force of the fluid, the cover layer 8 delaminates from the substrate 7 in a section 14 and / or the cover layer 8 detaches from the substrate 7 in section 14, a collecting channel 4 is provided which is formed in the substrate 7. The fluid can flow into the drainage channel 4, which is directly connected to the discharge channel 3, wherein a bridging channel can form between the cover layer 8 and the substrate 7 due to the detachment / delamination of the cover layer 8 from the substrate 7 in section 14. Thanks to the associated pressure reduction, the cover layer 8 does not detach further from the substrate 7, in particular not in a fastening region 10 surrounding the initial channel 4. This prevents the fluid from inadvertently escaping to the outside of the storage device 1.Thanks to the direct connection of the collecting channel 4 with the discharge channel 3, the storage device 1 or the flow cell can be used because the fluid can be transported via the discharge channel 3 as intended.

[0029] Fig. 1 d) shows that the discharge channel 3 and the collecting channel 4 are formed into the substrate 7.

[0030] By way of example, Fig. 6 shows a flow cell 20 according to the invention, which is provided with the storage device 1. It has mixing sections 16, 17 leading to ports 19, 21, as well as a reaction and / or detection chamber 18, which are fluidically connected to the discharge channel 3. It is understood that differently constructed flow cells, which have different components, could also be provided with the storage device 1.

[0031] In Fig. 3, further storage devices 1 a, 1 b, 1 c microfluidic flow cells are shown.

[0032] The storage device 1a according to Fig. 3 a) differs from the storage device 1 according to Figs. 1 and 2 in that no predetermined breaking point is provided on the storage chamber 2a, which leads specifically to a discharge channel 3a. Rather, in the storage device 1a according to Fig. 3a, an annular region 5a is provided, in which a cover layer 8a of a storage chamber 2a on a substrate 7a is connected to the substrate 7a in a fluid-tight manner, which can be opened in order to form a flow connection, in particular a bridging channel, from the storage chamber 2a to a collecting channel 4a and from there to the discharge channel 3a. A preferred direction towards which the annular region 5a should be opened is not provided.

[0033] The storage device 1b (see Fig. 3b) differs from that shown in Fig. 3a) in that a bulge 11 leading to a storage chamber 2b is formed in a collecting channel 4 next to a point at which the collecting channel 4b is connected to a discharge channel 3b. The bulge 11 forms a predetermined breaking point 6b and thus a preferred direction toward which a flow connection, in particular a bridging channel, is formed between the storage chamber 2b and the collecting channel 4b as well as the discharge channel 3b when a cover layer 8b detaches from a substrate 7b in an annular region 5b under pressure exerted on the storage chamber 2b.

[0034] In a further storage device 1c, which is shown in Fig. 3c), a predetermined breaking point 6c is provided, which is formed by a recess in the substrate 7c, to create a preferred direction for establishing a flow connection between a storage chamber 2c and a collecting channel 4c. During production of the storage device 1c, a cover layer 8c in the region of the recess 6c does not bond, or bonds less firmly, to the substrate 7c. When pressure is exerted on a wall of the storage chamber 2c, the annular region 5c opens, preferably in the region of the predetermined breaking point 6c. Between the collecting channel 4c, next to the predetermined breaking point, a connecting channel 5c is formed, by means of which the collecting channel 4c is connected to a discharge channel 3c.

[0035] Fig. 4 shows further storage devices I d, 1e, 1f, 1g of microfluidic flow cells, which differ from those of Fig. 3 in that collecting channels 4d, 4e, 4f, 4g do not completely enclose storage chambers 2d, 2e, 2f, 2g. A section in which the collecting channel 4d, 4e, 4f, 4g is not formed can be used to form other channels (not shown here). Such channels can, for example, be provided to lead to the storage chamber 2d, 2e, 2f, 2g, for example, for filling and venting the storage chamber 2d, 2e, 2f, 2g.

[0036] The storage device 1g, shown in Fig. 4d, differs from that of Fig. 4c in that no separate connecting channel is formed between a discharge channel 3g and a collecting channel 4g. The collecting channel 4g is directly connected to the collecting channel 3g. Another storage device 1h, shown in Fig. 5, is essentially constructed in the same way as that of Figs. 1 and 2, but differs in that a collecting channel 4h is not formed in a substrate 7h, but rather by a bulge in a cover layer 8h. Even with such a collecting channel 4h, when the fluid enters the collecting channel 4h and the cover layer 8h detaches from the substrate 7h, pressure can be reduced by fluid outflow, and further delamination of the cover layer 8h from the substrate 7h can be avoided. It is understood that the collecting channel 4h can only partially surround or completely enclose the storage chamber 2h.

[0037] The discharge channel 3, 3a - 3h can comprise several sections, between which, for example, a container or reaction chamber is formed, and leads to at least one further component of the flow cell. This component can be a measuring container or a container containing a reagent, in particular a dry reagent.

[0038] It is understood that the flow cell 20 according to Fig. 6 could also be provided with one of the storage devices 1a - 1h instead of the storage device 1. Other flow cells equipped with other components could also be provided with the storage device 1a - 1h.

Claims

1. Microfluidic flow cell with a storage device (1) comprising a storage chamber (2) for a fluid and a discharge channel (3) for fluid transport, characterized in that a collecting channel (4) is formed around the storage chamber (2) and is in flow connection with the discharge channel (3).

2. Flow cell according to claim 1, characterized in that the collecting channel (4) partially surrounds or completely encloses the storage chamber (2).

3. Flow cell according to claim 1 or 2, characterized in that the collecting channel (4) is in flow connection exclusively with the discharge channel (3).

4. Flow cell according to one of claims 1 to 3, characterized by a separation area (5) between the storage chamber (2) and the collecting channel (4), which can be opened to form a flow connection between the storage chamber (2) and the collecting channel (4).

5. Flow cell according to claim 4, characterized by a predetermined breaking point (6;11) for opening a, preferably direct, flow connection between the storage chamber (2) and the discharge channel (3) and / or a, preferably direct, flow connection between the storage chamber (2) and the collecting channel (3).

6. Flow cell according to claim 4 or 5, characterized in that the predetermined breaking point (11) of the collecting channel is formed by a bulge of an inner wall (12) of the storage chamber (2) towards the collecting channel (4) and / or a bulge of an inner wall (13) of the collecting channel (4) towards the storage chamber (2).

7. Flow cell according to claim 5 or 6, characterized in that that the discharge channel (3) and / or the collecting channel (4) is formed in a substrate (7) of the storage device (1) and / or a cover layer (8) of the storage device (1) that at least partially covers the substrate (7), wherein the cover layer (8) is preferably formed by a film or a membrane.

8. Flow cell according to one of claims 1 to 7, characterized in that the cover layer (8) forms a wall (9) of the storage chamber (2).

9. Flow cell according to one of claims 1 to 8, characterized in that the cover layer (8) is attached to the substrate (6) in the separation region (5), preferably in a fluid-tight manner.

10. A method for producing a microfluidic flow cell, in which a storage device (1) is formed which comprises a storage chamber (2) for a fluid and a discharge channel (3) for fluid transport, characterized in that a collecting channel (4) is formed around the storage chamber (2) and is in flow connection with the discharge channel (3). 1 1. Method according to claim 10, characterized in that the flow cell, in particular the storage device (1), is formed by a substrate (7) and a cover layer (8) which is attached to the substrate at least in sections, optionally in a fluid-tight manner, and the storage chamber (2), the discharge channel (3) and / or the collecting channel (4) are preferably formed by an intermediate space between the substrate (7) and the cover layer (8).

12. The method according to claim 10 or 11, characterized in that a flow connection between the storage chamber (2) and the discharge channel (3) is formed by opening a separating region (5) in which the cover layer (8) is connected to the substrate (7) in a fluid-tight manner in a region between the storage chamber (2) and the collecting channel (4).

Images