EP2675562A1

EP2675562A1 - Apparatus for hermetically sealed storage of liquids for a microfluidic system

Info

Publication number: EP2675562A1
Application number: EP11810611.1A
Authority: EP
Inventors: Peter Rothacher; Christian Dorrer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2011-02-15
Filing date: 2011-12-28
Publication date: 2013-12-25
Also published as: WO2012110159A1; US20140045275A1; DE102011004125A1; CN103402640B; US9757724B2; CN103402640A

Abstract

The present invention relates to an apparatus for hermetically sealed storage of liquids for a microfluidic system, which has at least one cavity and at least one sealing cone through which a connection to the microfluidic system can be established and which closes the cavity. The present invention also relates to the use of such an apparatus.

Description

description

title

Device for the hermetically sealed storage of liquids for a microfluidic system

In microfluidic systems, e.g. Lab-on-chip (LOC) systems, it is necessary to direct the biochemical reagents and the sample on or into the chip. Unlike simple lateral flow test strips for e.g. immunological

Detection methods often require several reagents in the chip system for molecular diagnostic tests. It is not always an easy-to-use and user-friendly on-chip storage in dried form, for example, lyophilized, possible. Another major difference between most molecular diagnostic tests and lateral flow test tires is the need to handle large volumes of analyte or wash solutions that are difficult to integrate on the chip due to their large volume of up to several milliliters. To meet these requirements, e.g. External chip storage vessels used with external syringe pumps and connections to the chip. Alternatively, the reagents are added manually to the reservoirs or reaction chambers of the chip. While it can easily pump in the first variant to impurities or air pulling the syringes, make in the second variant, especially operator errors by the user is a problem. In addition, are also

Systems with compressed air-driven addition of fluids known in which, however, difficult to deliver reproducible volumes and compressed air can get into the fluidic system. Therefore, systems have been developed in which the storage of the reagents takes place directly integrated on the chip. WO 2006053588 describes for this purpose an apparatus for use in a microfluidic system, in which a liquid is stored in a blister reservoir. After the blister has been associated with the microfluidic system, a film is pierced between the blister reservoir and the microfluidic system, so that creates a fluid connection between the blister reservoir and the microfluidic system. Subsequently, the liquid is brought into a channel of the microfluidic system by manual pressure on the blister reservoir. In order to prevent premature puncturing of the foil between the blister reservoir and the microfluidic system, the system of blister reservoir and microfluidic system comprises a special holding device.

Another device is disclosed in WO 2008076395. In this device, several blister reservoirs are brought into direct contact with the microfluidic system only at the moment and opened by needles in which the liquids stored in them are to be used. In addition, by alternately compressing the blister reservoirs, the system allows individual substances in the microfluidic system to be mixed. DISCLOSURE OF THE INVENTION

The present invention is an apparatus for hermetically sealed storage of liquids for a microfluidic system having at least one cavity for receiving a fluid and at least one sealing cone, above which a fluidic connection to the microfluidic system can be produced.

The term "hermetically sealed storage of liquids" is understood in the following as a storage of liquid already contained in the device or introduced by the user into the device until it is used in a microfluidic system which is completely sealed off and sealed off from the outside, so that none Impurities can penetrate.

A "microfluidic system" is a miniaturized fluid system, such as icro-Total-Analysis-Systems (pTAS) or LOC-systems, which has the advantage of summarizing and automating individual steps while reducing them to a microscale The potential of such systems lies above all in the automation facility, the fast reaction times and the reduction of the sample and reagent volumes, so that an analysis laboratory in the form of a miniaturized system becomes possible In the case of the fluids, reagents, samples or analytes and / or solvents! In LOC systems, the chip is placed or placed in a laboratory device for analysis. The device according to the invention with the necessary fluids is either integrated into the LOC system and firmly connected to it ^' or stored separately from the LOC system and only firmly connected to the LOC system during operation.

The term "cavity for receiving a fluid" referred to a space defined by outer boundaries space _"which is suitable for containing liquids. In a preferred embodiment, the at least one cavity of at least two is connected into sub-areas to each other, preferably welded or glued, parts In a variant of this embodiment, the cavity consists of two polymer plates, for example, by means of injection molding, milling, deep-drawing or hot stamping, which are connected to one another by welding or gluing, for example ,

In a further variant of this embodiment, the at least one cavity is formed from at least two thermoformed polymer films or plates which are welded or bonded together in partial surfaces, so that cavities are created between the non-connected partial regions which are suitable for receiving the fluids. Suitable materials are in particular suitable plastics which are thermoformed or pressed.

In a third variant of this embodiment, the cavity is bounded by an elastomeric membrane, which is connected in some areas with a polymer foil or plate, for example welded or glued, so that arise between the non-connected portions cavities, which are suitable for receiving the fluids , This causes the elastomeric membrane rests in the unfilled state on the polymer film or plate. This embodiment has the advantage that no ventilation opening is required, since the elastomeric membrane inflates during filling and, as liquid is dispensed into the microfluidic system, contracts again. If necessary, the connection to the microfluidic system can also be achieved via the elastomeric membrane. Alternatively, a one-piece construction, for example as a thermoformed plastic molding, possible.

Care must be taken when choosing materials that they are inert to the fluids to be stored in them. For example, thermoplastic materials such as polystyrene, polycarbonate, polyethylene, polypropylene, polymethyl (meth) acrylate, cyclic olefin copolymers or cyclic olefin polymers can be used as materials. In this context, it is a further decisive advantage of the device according to the invention that it can be manufactured as a disposable article.

In general, the intervening cavities have a volume of from 10 μl to 10 ml, preferably from 20 μl to 5 ml, particularly preferably from 200 μl to 1 ml, the end values of the ranges and all individual values between them being included. The base of the cavity may, for example, be circular, oval or rectangular. Alternatively, the cavity may also be used as a channel, i. significantly longer than wide and high, e.g. be designed as a meandering channel. This embodiment has the advantage that the inclusion of air bubbles or incomplete emptying is avoided during pressure-driven filling or emptying.

In another embodiment, the cavity additionally has a channel structure through which the fluids, e.g. Reagents, solvents or gases for venting. The channel structure has the advantage that optionally a metered addition of the fluids is possible and greater flexibility is achieved with respect to the placement of the at least one sealing cone.

In a preferred embodiment, the at least one cavity is designed as a blister structure, ie it has a bubble-shaped configuration. Blisters offer the advantage that they can be produced inexpensively from, for example, thermoformed plastics, and that the flexibility also makes it possible to squeeze out the fluids. Further, the use of a blister has the advantage of not requiring a vent since the blister collapses as the fluid is dispensed into a microfluidic system. It is also possible a compound of both structures, ie a bubble-shaped reservoir and a subsequent channel.

Of course, it is possible that the device has more than one cavity for receiving different fluids. In a preferred embodiment, the device has at least one cavity for receiving reagents in the form of a fluid. In a further embodiment, the device has at least one cavity for receiving a sample to be analyzed as a fluid. A device having at least two cavities, i. One for receiving reagents and one for receiving a sample, of course, is also possible.

In a further embodiment, the device has at least one cavity as a waste reservoir or at least one cavity is used as a waste reservoir for receiving reagents or for receiving a sample to be analyzed after emptying into the microfluidic system. The term "waste reservoir" in the following refers to a collecting device for already used fluids from the microfluidic system, which has the advantage that used media can be safely stored without contaminating the system Design as a disposable item, a simple and safe disposal together with the invention

Device be made. If the device has more than one cavity, any number of them can serve as a waste reservoir. In this case, it is also possible that the device comprises a first non-fluid-filled cavity, which later serves as a waste reservoir.

In most cases, the cavity initially filled with reagents, sample or solvent will not serve as a waste reservoir until the fluid has escaped from the cavity after establishing connection to the microfluidic system. However, it is also conceivable that the fluid contained in the cavity has special properties, which are for the use of the cavity as

Waste reservoir are crucial, such as a disinfectant. If the cavity is used from the outset as a waste reservoir, the waste reservoir in a preferred embodiment may contain an absorbent material, preferably a superabsorbent or superabsorbent particles or fibers, so that nothing can escape from the device in the return flow of waste fluid. This is particularly advantageous if the device is aligned vertically in the application and the waste reservoir is filled from below.

In one embodiment, the at least one cavity has a ventilation opening, preferably a ventilation channel. This can during the

Draining the fluid from the cavity to flow air and vice versa when filling the cavity escape the air or other gases contained therein. During storage of the device, however, the vent is closed, so that no fluid can escape or contaminants can penetrate from the outside. In the simplest case, this vent only consists of each other! foil areas not welded in this area. As long as the device is held vertically, air can escape through the intermediate gap, but fluids do not. Thus, the contamination of other system components such as the laboratory device or connecting hoses is avoided.

In another embodiment, the capillary venting channel is closed after filling the cavity, e.g. by welding, clamping or with an adhesive film, so that leakage or contamination of the liquid during storage and during operation is particularly reliably avoided.

In a further embodiment, the vent opening is closed by a sealing cone. In this case, by opening the sealing cone, a fluid-moderate connection to the microfluidic system is produced and the aeration takes place through the microfluidic system. This embodiment also has the advantage that leakage or contamination of the liquid during storage is avoided particularly reliably. In addition, this embodiment has the advantage that the ventilation opening can be opened simultaneously with the other fluidic connections, whereby the handling is simplified.

It is also conceivable that the device has one or more cavities configured as blisters, which do not require vent openings and, in addition, comprises one or more cavities which are not configured as blisters and may require vent openings if they serve, for example, as a waste reservoir. In a further embodiment, the at least one cavity of the device has a filling opening, preferably a funnel-shaped filling nozzle. The user can fill in the sample to be examined via the filling opening, for example, while further cavities without a filling opening already contain reagents that have already been introduced. In diagnostic tests such as blood, sputum, urine, plasma _"serum, washes or secretions are possible as a sample. The sample can be added to the filling opening by means of syringes or icropipettes. Filling and ventilation openings are then closed. For this purpose, preferably automatic welding devices, plugs, seals, clamps or adhesive films are used.

In the following, the term "sealing cone" designates a component, by way of which a fluidic connection can be produced between the at least one cavity and the microfluidic system Moreover, the sealing cone serves for closing the at least one cavity In the simplest embodiment, however, filling and emptying of the cavity takes place only via the sealing cone, ie the hermetically sealed storage takes place only by closing and opening the sealing cone fluidic functionality and the number of cavities, the device also has a plurality of sealing cones.

By opening the sealing cone, a fluidic connection between the at least one cavity of the device, and a microfluidic system is provided, so that the passage of liquid is made possible. The connection is at the same time fluid-tight, that is to say no unwanted escape of fluid from the connection between the cavity and the microfluidic system is possible.

In a preferred embodiment, the sealing cone comprises at least one of the following components, over which a. Connection between the sealing cone and the mikrofluid ischen system can be produced: predetermined breaking point, pin, elastomer seal and / or foil. In the following, the term predetermined breaking point designates a securing element that is designed such that it breaks deliberately under mechanical stress and thus establishes a connection. By using a pin, in particular in combination with a predetermined breaking point, pressure is exerted on the sealing cone as long as desired by pushing in the pin until it gives way and a connection between the device and the microfluidic system is released. Alternatively, the pin can also be integrated into the microfluidic system and, similar to a key, result in pressing or pressing the device against the microfluidic system for opening the sealing cone. An elastomer seal is an elastically deformable plastic seal _» which deforms elastically under tensile and compressive load and returns to its original shape when the load is released. Specifically, the elastomeric seal can be designed as a sealing film. This has the advantage that it closes again after the connection to a channel of the microfluidic system has been established, as soon as the device is separated from the microfluidic system.

The sealing cone can have various shapes. For example, the shapes of the sealing cone are based on the shape of the connection point of the microfluidic system in order to ensure the highest possible connection between the device and the microfluidic system. The sealing cone preferably fits a key directly into the connection point of the microfluidic system, which forms the associated lock.

When opening the sealing cones, it is possible that by pressure on a point several sealing cones are opened simultaneously, e.g. if they are superimposed or sequentially connected to each other and are opened by a pressure point. Conversely, it is possible that by pressure on a sealing cone liquid can pass from several cavities, since all cavities are closed by the same sealing cone. This is particularly advantageous when fluids from different cavities, e.g. Sample and buffer solution, to be mixed together. In another variant, it is possible to open several cavities in succession by sequentially pressing a plurality of sealing cones.

In a particular embodiment, the device has a plurality of cavities, which are arranged as on a punched card. For example, a role that over the Drives device that squeeze cavities in a predetermined order. The movable roller is therefore similar to a peristaltic pump. Due to the speed of the roller and the cross-section of the cavities in the device, the volume flow in the microfluidic system can also be controlled.

However, it is also possible that a slight upper pressure prevails in the cavity. This has the advantage that, after establishing a connection to the microfluidic system, the fluid leaves the cavity faster via the sealing tone and no additional pressure must be exerted on the cavity.

Of course you can also combine these different options as you like.

Through the use of a sealing cone has surprisingly been found that the device according to the invention a safer storage of

Ensures fluids and easier handling, because on very pressure-sensitive connecting materials such as thin films and depending on the design, if necessary, on the use of needles or spikes, etc. can be dispensed with to open the sealing cone. In addition, fewer components are used than is the case with currently known devices.

Furthermore, the sealing cone serves as an adjustment aid when inserting or arranging the device on a microfluidic system, since the sealing cone is inserted accurately into the system. The device is stored until the liquid is used together with or separately from the microfluidic system. If the device is stored together with the microfluidic system, this is already arranged on the microfluidic system and connected to this fixed and irreversible, possibly also flexible with an intermediate clearance. For establishing the connection, various techniques are conceivable, for example by

Welding, gluing, laminating, with double-sided adhesive tape or gluing with intermediate layers of elastic materials, eg foam rubber or an elastomer. In this case too, however, the liquid in the device is still separated from the microfluidic system by the sealing cone, which is opened only during operation. Under a separate storage is that of the microfluidic system understood as a separate component of a kit, in this case, the two components are connected immediately before or during insertion into the laboratory device, for example by gluing, clamping or stacking.

In a further aspect, the present invention relates to the use of the device described above in a microfluidic system. In this case, the use of the following steps:

a) providing a device as described above

b) filling the at least one cavity with a fluid,

c) closing the at least one cavity, and

d) establishing a fluidic connection between the device and the microfluidic system via the sealing cone of the device. As already described above, a corresponding device for storing liquids is provided and filled. Step b) may be e.g. with regard to reagents directly to the manufacture of the device, or at least partially, e.g. with regard to the sample to be analyzed, carried out by the user himself. In the same way, this applies to step c).

In step d), a connection is made between the device according to the invention and the microfluidic system via the opening of the sealing cone. The sealing cone can be opened, for example, by manually placing the device and the microfluidic system together and then compressing, so that the device is opened upon compression , Alternatively, the opening takes place as an automated step and is carried out automatically within a laboratory device accordingly. Alternatively, when the device and the microfluidic system are placed on top of one another, they can snap into place. In a preferred embodiment, the sealing cone is opened in step d) by pressing against a mechanical resistance on the microfluidic system, or with the aid of a mandrel or a needle in the microfluidic system. Alternatively, the mandrel or the needle may also be integrated into the device for storing the liquids. If step d) is automated, the opening can be carried out by the laboratory device, by the pressing by a mechanical actuator, such as an electric or pneumatic linear actuator, is made. Preferred embodiments of needles have at the tip a notch, a hole with transverse bore or openings, which ensure that in the pierced opening of the sealing cone remains a liquid-free opening. At the same time, however, the needle must be designed so that a secure seal between

Needle and mikroftuidischem system or needle and device is created, comparable to a seal through a septum. Preferably, the at least one needle or the at least one mandrel is arranged so that it can not come to an early opening of the sealing cone during the joint storage of the device with the microfluidic system. This is achieved for example by a separate storage of the needle. The arrangement of the needle or the dome on the microfluidic system or alternatively on the device itself is of course such that there is no risk of injury to the user

In a further embodiment, the microfluidic system has an elastomeric sealing membrane which is opened together with the sealing cone of the device in step d) for producing the fluidic connection. The elastomer seal is usually located on the opposite side of the sealing cone of the microfluidic system.

In any case, the use of the device of the invention allows the controlled addition of stored liquid to a microfluidic system. In addition, a precise control of the liquid volumes supplied to the system of up to several milliliters is possible. For this purpose, after establishing the connection to the microfluidic system, the entire stored in the cavity of the device liquid is delivered to the microfluidic system. This will ensure that a predetermined amount of fluid is released into the microfluidic system.

As a rule, the liquid enters the microfluidic system by gravity, capillary forces and / or slight overpressure in the cavity. Alternatively or additionally, a manual or mechanical pressing, in particular in a blister structure of the device, possible. In the simplest case, the cavity of the device is arranged over a channel of the microfluidic system, so that the liquid after establishing the connection to the microfluidic system by Gravity enters the channel. Alternatively, a pressure on the cavity can be exerted via a mechanical actuator contained in the laboratory device, for example an electric or pneumatic linear actuator. As a weather alternative, especially when using a blister structure, _" a pneumatic top pressure can be applied to the entire outside of the device. In a further variant, a pump is located inside the microfluidic system, for example a peristaltic pump, which sucks the fluid out of the cavity.

drawings

Further advantages and advantageous embodiments of the device according to the invention and of the method according to the invention are illustrated by the figures and exemplary embodiments and explained in the following description. It should be noted that the illustrations and embodiments have only descriptive character and are not intended to limit the invention in any way.

Embodiments of the invention

Fig. 1 shows schematically various embodiments of the sealing cone

101a -101g.

FIG. 2A schematically shows a sealing cone 201 comprising a predetermined breaking point 202 and a pin 203.

FIG. 2 B shows, in addition to the sealing cone 201, which includes a predetermined breaking point 202 and a pin 203, a microfluidic system 205 which has a sealing foil 206 and a channel 207. The sealing cone 201 is already arranged on the microfluidic system 205. It is shown how when a force is exerted - indicated by the arrow 204 - on the sealing cone 20, the predetermined breaking point 202 by the pin 203 which abuts the film 206, is pressed so that the sealing cone via the connection to the channel 207 of Microfluidic system 205 is produced.

3 A schematically shows a device 300 for storing fluids for a microfluidic system 303, comprising a fluid-filled cavity 302, designed here as a channel, and a sealing cone 301, via which a connection to a channel 305 of the microfluidic system 303 can be produced is and closes the cavity 302. The microfluidic system 303 comprises a sealing film 304. In this example, the device 300 is stored together with the microfluidic system 303, so there is a so-called multi-layer structure. It is not shown that in this example the liquid-filled cavity 302 designed as a channel is also closed at its end remote from the cone.

FIG. 3B schematically illustrates how, by applying a force 306, either to the device 300, or to the microfluidic system 303, or both, the sealing cone 301 is opened to connect to the channel 305 of the microfluidic system 303 ,

Flg. 4A schematically shows three views of the same device 400. The device comprises three sealing cones 401 and three hollow spaces 402, 403 and 404 designed as a bead. The cavity 403 serves as a reagent reservoir. Cavity 402 is a sample reservoir and cavity 404 is a waste reservoir. About the Dichtkonen 401 is a connection to a microfluidic system, not shown to produce.

4B shows a schematic view of the underside of the device 400 from FIG. 4A, in which the liquid passes in the direction of gravity from the device into the microfluidic system (not shown). It can be seen from this illustration that the device comprises, in addition to the three sealing cones 401 and the three cavities 402, 403 and 404 configured as blisters, a venting channel 405 and a filling channel 407. In addition, the connection to cavity 403 is sealed by a pinch weld 406. Furthermore, it can be seen that the channel 407 for filling the sample reservoir 402 is closed by a plug 408. This allows the reservoir to be filled with a sample and hermetically sealed before the device is placed on the microfluidic system, not shown.

FIG. 5 A schematically shows a needle 501 with a V notch 502.

FIG. 5B schematically shows a hollow needle 503 with a transverse bore 504.

These types of needles may, for example, be used to pierce the sealing cone and to establish a connection between the at least one cavity of the device and the at least one channel of the microfluidic system.

6A schematically shows a device 600 comprising a sealing cone 601 and a liquid-filled cavity 602, and a microfluidic system 603 comprising a channel 604 and an elastomeric seal 605, here an elastomeric membrane. Further shown is a V-notched needle 606 which has been stored separately from the device.

FIG. 6B schematically shows how the V-notch V-notch 60 has pierced the sealing cone 601 and thus fluidically interconnected the fluid-filled cavity 602 and the channel 604 of the microfluidic system 603 via the sealing cone 601. The liquid is then forced out of the cavity 602 by means of a force (indicated by the block arrow) exerted, for example, by a plunger 607. FIG. 7 schematically shows a microfluidic system 701 comprising a sheet 702, a channel 703 and an undercut needle 704. The undercut needle pierces the sealing tone 705 of the device when placed on the microfluidic system 701.

Claims

claims

1, apparatus for the hermetically sealed storage of liquids (300) for a microfluidic system (303),

comprising at least one cavity (302) for receiving a fluid and at least one sealing cone (301) for closing the cavity (302), via which a fluidic connection to the mlkrofluidischen system (303) can be produced.

2. Apparatus according to claim 1, characterized in that the at least one cavity (302) has a channel and / or blister structure as a whole or in partial areas.

3. Device according to claim 1 or 2, characterized in that the at least one cavity (302) is formed from at least two parts connected in partial surfaces, preferably welded or glued, parts, wherein the parts are selected from the group of polymer film, polymer plate and elastomeric membrane.

4. Device according to one of claims 1 to 3, characterized in that the at least one cavity (302) has a volume of 10 μΙ to 10 ml, preferably from 20 μΙ to 5 ml, more preferably from 200 μΙ to 1 ml.

5. Device according to one of the preceding claims, comprising at least one cavity (302) for receiving reagents as a fluid (403).

6. Device according to one of the preceding claims, comprising at least one cavity (302) for receiving a sample to be analyzed as a fluid (402).

7. Device according to one of the preceding claims, comprising at least one cavity (302) as a waste reservoir (404); or at least one cavity (302) for receiving reagents as fluid (403) or at least one cavity (302) for receiving a sample to be analyzed as fluid (402), which serve as a waste reservoir after emptying.

8. The device according to claim 7, characterized in that the Äbfallreservoirs an absorbent material, preferably superabsorbent ^' particles or fibers containing.

9. Device according to one of the preceding claims, characterized in that the at least one cavity (302) has a filling opening (407), preferably a funnel-shaped filling nozzle.

10. The device according to claim 9, characterized in that the filling opening is closed by a plug, a crimping, a clamp, a seal or an adhesive tape.

1 1. Device according to one of the preceding claims, characterized in that the at least one cavity (302) has a vent opening (405), preferably a capillary venting channel.

12. Device according to one of the preceding claims, characterized in that the sealing cone (301) comprises at least one of the following components, via which a connection between the sealing cone (301) and the microfluidic system can be produced predetermined breaking point (202), pin (203) , Elastomeric seal and / or foil.

Use of a device (300) according to any of claims 1-12 in a microfluidic system (303) comprising the steps;

a) providing a device (300) according to any one of claims 1-9

b) filling the at least one cavity (302) with a fluid,

c) closing the at least one cavity (302), and

d) establishing a fluid connection between the device (300) and the microfluidic system (303) via the sealing cone (301) of the device (300).

14. Use of a device (300) according to claim 13, characterized in that the sealing cone (301) is opened in step d) by pressing against a mechanical resistance on the microfluidic system, or by means of a dome or a needle in the microfluidic system.

15. Use of a device {300} according to claim 13, characterized in that the microfluidic system comprises an elastomeric sealing membrane, which is opened together with the sealing cone (301) of the device (300) in step d) for the production of the fiuidischen connection.