FR3074069A1 - DEVICE FOR INJECTING A FLUID SAMPLE - Google Patents

Abstract

The invention relates to a device (2) for injecting a fluid intended to be fitted onto a microfluidic device (1) which comprises a fluidic network comprising a fluidic inlet (IN1) for receiving a fluid sample and a pneumatic network. comprising at least one auxiliary pneumatic input (IN aux) intended to be connected to a pneumatic supply source (3) and an auxiliary pneumatic output (OUT_aux) communicating with said auxiliary pneumatic input. Said injection device comprises a fluidic outlet (OUT2) arranged in a fluidic connector adapted to connect sealingly to said fluidic inlet (IN1) of said microfluidic device and a pneumatic inlet (IN2) arranged in a pneumatic connector adapted for sealingly connecting to said auxiliary pneumatic output (OUT_aux) of said microfluidic device.

Description

Fluid sample injection device

Technical field of the invention

The present invention relates to a device for injecting a fluid sample.

The invention also relates to a microfluidic system comprising a microfluidic device and an injection device used to inject a fluidic sample into said microfluidic device.

Finally, the invention relates to a method for injecting a fluidic sample, implemented using said injection device adapted to the microfluidic device.

State of the art

There are many devices for injecting a fluid sample into a microfluidic device. For the simplest, it may be a plunger device such as a syringe, for example equipped with a Luer type connector to connect to a fluid inlet of the microfluidic device. It can also be a device already integrated into the card such as that described in patent application EP2679307A1. This solution consists in placing the fluid sample in a pocket glued to a microfluidic card and closed by a film interposed between said pocket and a fluid inlet of the card. After removing the film, mechanical pressure on the top of the pocket allows the liquid sample to be injected into the card.

The various solutions described above have certain drawbacks, however. The plunger solution does not allow easy adjustment of the volume of liquid injected, nor does it allow the liquid sample to be stored in the syringe. The solution described in document EP2679307A1 also has two main drawbacks:

The pocket forming the reservoir is stuck on the card. This means that the card must always be associated with a particular tank and this therefore does not make it possible to have separate devices.

The injection is controlled by mechanical pressure, generally manually. This does not allow the volume injected to be adjusted precisely, especially when the volume is particularly low (less than 10ΟμΙ).

The object of the invention is therefore to propose an injection device which overcomes the drawbacks of the previous solutions. This can in particular be independent of the microfluidic device and makes it possible to precisely adjust the volume injected, even in the event of low volume.

Statement of the invention

This object is achieved by a device for injecting a fluid intended to be adapted on a microfluidic device which comprises a fluidic network comprising a fluidic inlet (IN1) for receiving a fluidic sample and a pneumatic network comprising at least one inlet auxiliary pneumatic tire intended to be connected to a pneumatic power source and an auxiliary pneumatic output communicating with said auxiliary pneumatic input, said injection device comprising:

A housing,

A fluid network arranged in said housing and which comprises a reservoir arranged in an internal space of the housing and intended to receive said fluid sample to be injected into said microfluidic device and a fluid outlet connected to said reservoir and arranged in a fluid connector adapted for sealingly connect to said fluid inlet of said microfluidic device to inject said fluid sample into the fluid network of said microfluidic device,

A pneumatic network arranged in said housing (20) and comprising a pneumatic inlet,

Said pneumatic inlet being arranged in a pneumatic connector adapted to connect in leaktight manner to said auxiliary pneumatic outlet of said microfluidic device.

According to a feature, said device comprises at least a first face on which opens said pneumatic inlet and a second face on which opens said fluid outlet and said first face and said second face are parallel.

According to another particularity, the device comprises an elastic deformable membrane arranged in said reservoir and forming a sealed interface for isolating the fluidic network from the pneumatic network.

According to another particular feature, the membrane is made of a deformable material such as an elastomer of the family of silicones.

According to another particular feature, the device comprises at least one film arranged on said housing to close off said fluid outlet and said pneumatic inlet.

According to another particular feature, said pneumatic network comprises a channel connected to said pneumatic inlet and opening into said tank.

According to another particular feature, said fluid network comprises a channel connecting said reservoir to said fluid outlet.

According to another particularity, the device is composed of an assembly of several superimposed substrates.

The invention also relates to a microfluidic system comprising a microfluidic device which comprises a fluidic network comprising a fluidic inlet for receiving a fluidic sample and a pneumatic network comprising at least one auxiliary pneumatic inlet intended to be connected to a source of pneumatic supply and an auxiliary pneumatic outlet communicating with said auxiliary pneumatic inlet, characterized in that it comprises a fluid injection device as defined above, said pneumatic inlet of the injection device being configured to connect to said auxiliary pneumatic outlet of the microfluidic device and said fluid outlet of the injection device being configured to connect to the fluid inlet of the microfluidic device.

According to a particular feature, the pneumatic network of the microfluidic device comprises a pneumatic control input intended to be connected to a pneumatic power source.

According to another particularity, the fluidic network of the card comprises several fluidic valves actuable by said pneumatic network, via said pneumatic control input by which a pneumatic force is generated.

According to another particularity, each fluid valve comprises a microfluidic capsule actuable between a first closed state blocking the flow of a fluid and a second open state authorizing the flow of said fluid.

According to another particular feature, the microfluidic device comprises at least one deformable membrane arranged in each capsule and actuable between two states by said pneumatic force.

The invention also relates to a method for injecting a fluid sample into a microfluidic device which comprises a fluid network comprising a fluid inlet for receiving a fluid sample and a pneumatic network comprising at least one auxiliary pneumatic inlet intended to be connected on a pneumatic power source and an auxiliary pneumatic outlet communicating with said auxiliary pneumatic inlet, said method being implemented using an injection device as defined above, the reservoir of said injection device comprising said fluid sample, said method comprising the following steps:

Connection of the injection device to the microfluidic device by connecting the fluid outlet of the injection device to the fluid inlet of the microfluidic device and the pneumatic inlet of the injection device to the auxiliary pneumatic outlet of the micro device -fluidique,

- Connection of the auxiliary pneumatic input of the microfluidic device on a pneumatic power source,

- Application of a pneumatic force through the auxiliary pneumatic inlet of the microfluidic device and the pneumatic network of the injection device so as to inject the fluidic sample into the fluidic network of the microfluidic device via the fluid outlet of the injection device and the fluid inlet of the microfluidic device.

Brief description of the figures

Other characteristics and advantages will appear in the following detailed description given with reference to the appended drawings in which:

FIG. 1 represents, in perspective, a microfluidic device produced in the form of a microfluidic card;

Figure 2 shows, in side view and schematically, the microfluidic device of Figure 1;

FIGS. 3A to 5B represent different alternative embodiments of a microfluidic capsule which can be used in a microfluidic device such as that shown in FIG. 1;

FIGS. 6A to 6C illustrate, in side view and schematically, a first embodiment of the injection device of the invention;

Figures 7A to 7C illustrate, in side view and schematically, a second embodiment of the injection device of the invention;

FIGS. 8A and 8B represent the different stages of operation of the injection device, respectively according to the first embodiment and according to the second embodiment, associated with a microfluidic device;

Detailed description of at least one embodiment

In the following description, the terms top, bottom, top, bottom, are to be understood by taking as a reference a vertical axis. In the accompanying drawings, this axis (X) is drawn vertically in the plane of the sheet.

The invention relates to a device 2 for injecting a fluid sample into a microfluidic device 1. The two devices are initially independent. The injection device can be adapted on the microfluidic device for injecting the fluid sample. The two devices form a complete microfluidic system which can be used during an analysis of a fluid sample.

The injection device can be of the single-use type, that is to say disposable.

In the present application, by suitable connectors, it should be understood that the two connectors used have a complementary architecture making it possible to make a reliable and sealed connection. This will include a male / female type connection. It could also be a connection made by friction or Luer type or any other possible solution.

By fluid sample, it should be understood that it can be a liquid or even a gas. Preferably, it will be a liquid type sample.

The microfluidic device compatible with the injection device of the invention can be of all types, that is to say that it can take any possible structure, whether for its external shape or for its fluid architecture. internal.

In a nonlimiting manner, the microfluidic device can be produced in the form of a card, known as a microfluidic card. This card can have a rectangular format.

By fluidic network is meant fluidic elements such as one or more fluidic inlets, one or more fluidic outlets, one or more reservoirs, connecting channels, chambers, fluidic valves or any other element of this type.

By pneumatic network is meant pneumatic elements such as one or more pneumatic inlets, one or more pneumatic outlets, connecting channels, chambers or other elements of this type.

The microfluidic device 1 has a fluid inlet IN1 through which the fluid sample is injected into the fluid network of the microfluidic device 1. This fluid inlet IN1 can be formed in a fluid connector. This connector can be of the male type and is arranged to cooperate with a corresponding suitable connector.

FIG. 1 shows an example of a micro-fluidic device 1 of the card type, as it could be used in the context of the invention. Of course, this device is to be considered in a nonlimiting manner for the description of the invention.

Such a microfluidic device is described in particular in application EP3085444A1.

As an example and without limitation, this microfluidic device 1 may include two substrates 10, 11 and a deformable membrane 12 disposed between the two substrates. Each substrate 10, 11 has two surfaces, a so-called upper surface and a so-called lower surface. The lower surface of the first substrate 10 faces the upper surface of the second substrate 11 and both form the microfluidic surfaces of the device, since it supports its fluid network. The two substrates can have a rectangular, circular or any other shape.

Each of the first 10 and second 11 substrates has a thickness, for example between approximately 200 μm and 10 mm and an area on the order of several square centimeters, typically an area equivalent to that of a microscope slide, a well plate (called 96 well plate ”) or a credit card. The deformable membrane has a thickness of the order of a hundred microns (10pm to 1mm), for example 300pm.

The material of the first substrate 10 and / or of the second substrate 11 is selected from the following materials: polycarbonate polymer, PMMA, COC, silicon, and paper.

The membrane 12 is formed from a material which is very elastically deformable, allowing it to return to its initial shape after deformation. The material is chosen with a percentage of elastic deformation at least equal to 200% (an elongation of twice its initial size before deformation) and up to 1000%. Of course, the material and its deformability characteristic can be adapted to the intended application.

The membrane 12 can be made of an elastomeric material of the family of silicones such as MQ (Methyl-Polysiloxanes), VMQ (Vinyl-MethylPolysiloxanes, PVMQ (Phenyl-Vynil-Methyl-Polysiloxanes) or elastomer of thermoplastic type (TPE ), for example TPE-S, TPS, TPE-E, TPC.

Without limitation, the fluid network of the device 1 shown in Figures 1 and 2 may include a series of microfluidic capsules 13.

Each microfluidic capsule 13 of a microfluidic device comprises a chamber 130 formed by a cavity into which an inlet channel opens and from which an outlet channel emerges. The membrane 12 is deformable inside the chamber of each capsule allowing, depending on its position, to confer at least two distinct states on the microfluidic capsule. Each capsule can be controlled individually by action of the part of the membrane associated with the capsule. Depending on the position of the membrane, the volume of the chamber 130 varies, between an almost zero volume and a maximum volume.

Different capsule configurations are possible. Depending on the arrangement of the capsule, when its membrane 12 is at rest, the capsule may be in the first state or in the second state. As with an electrical switch, we can therefore speak of a normally closed or normally open configuration.

The membrane 12 is adapted to open or block the passage of the fluid as well as to pump the fluid from a reservoir or a chamber to at least one other chamber.

The capsules can thus have different shapes and configurations:

Figures 3A and 3B

In FIGS. 3A and 3B, the capsules have the shape of a semi-spherical cap. In FIG. 3A, the capsule 13 is in a closed state. The membrane 12 is put in a deployed shape and is pressed to perfectly match the shape of the cavity. The volume between the membrane 12 and the cavity is almost zero, thereby blocking the flow of the fluid through the chamber 130. FIG. 3B illustrates a view of the same microfluidic chamber 130 in an open state. The corresponding part of the deformable membrane 12 is in the rest state and allows the fluid to flow through the chamber.

Figures 4A and 4B

Each cavity is represented in the form of a semi-spherical cap. In FIG. 4A, the capsule is in a closed state, the membrane 12 is however not deployed. In FIG. 4B, the membrane 12 is deployed and allows the flow of fluid through the chamber, from the inlet channel to the outlet channel.

Figures 5A and 5B

FIGS. 5A and 5B represent an operating architecture equivalent to that of FIGS. 4A and 4B, the difference residing in the fact that the microfluidic capsule is of cylindrical shape and not in the shape of a hemispherical cap.

The microfluidic device 1 is associated with an actuation system adapted to act on the membrane 12 at the level of each capsule in order to switch the selected capsule between its two states. The actuation system includes a pneumatic power source 3.

To connect the microfluidic capsules to each other, the device comprises microfluidic communication channels 14 forming the inlet and outlet channels described above. According to the embodiment chosen, they are formed on one or the other of the two microfluidic surfaces of each substrate 10, 11.

Without limitation, each communication channel 14 has a length of between approximately 0.5 mm and 5 mm and a section of between approximately 50 μm and 500 μm on the side. According to a preferred embodiment of the invention, the volume of a microfluidic channel 14 is at least ten times smaller than the volume of a microfluidic chamber 2.

The fluid input IN1 is produced through the upper substrate 10 of the card and may have its connector on the upper surface of the card.

The micro-fluidic device 1 comprises a pneumatic network. This pneumatic network may include one or more pneumatic control inputs 15 each opening at a microfluidic chamber 2 of a capsule. These control inputs 15 are used to actuate the deformable membrane 12 by applying a pneumatic force generated by a pneumatic power source.

According to the configuration of the capsule 13, the displacement of the membrane 12 between its two positions can be achieved by applying a positive pressure or a negative pressure on its pneumatic control input.

The actuation system may include a control unit configured to control each control input 15 in a suitable manner, for example according to a given sequence. The control can be global, all the inputs 15 being connected to the same pneumatic source 3, or selective, each input being able to be activated individually. Pneumatic valves are then controlled by the control unit to select each control input 15.

The fluidic network and the pneumatic network of the device 1 can be machined according to methods known by the plastics industries such as mechanical machining with a numerically controlled machine, by 3D printing, or preferably by injection.

The first substrate 10, the membrane 12 and the second substrate 11 are assembled so as to ensure sealed contact between the membrane 12 and the two microfluidic surfaces of the first and second substrates, while providing a flow space at the level of the capsules 13 and microfluidic channels 14. The assembly can be carried out by gluing, by plasma, or by mechanical plating.

According to a particular aspect of the invention, the pneumatic network of the microfluidic device also includes an auxiliary pneumatic inlet INaux and an auxiliary pneumatic outlet OUTaux connected together by a connecting channel. The auxiliary pneumatic input IN aux is arranged in a pneumatic connector intended to be connected to a pneumatic power source, this power source can be identical to the pneumatic source 3 used for the actuation of each fluidic valve described above. above. The auxiliary auxiliary output OUT aux is also arranged in a pneumatic connector suitable for establishing a connection with an external device.

The auxiliary pneumatic output OUT aux is thus available directly on the microfluidic device 1 for an external device.

The connector in which the auxiliary aux OUT output is formed may be of the male type.

The auxiliary pneumatic input IN aux, the auxiliary pneumatic output OUT aux and their connecting channel are advantageously produced by a channel traversing the card over its entire thickness, opening onto the lower surface to form the auxiliary pneumatic input and on the upper surface to form the auxiliary pneumatic outlet. The connector of the auxiliary output can be male. Any other arrangement could be envisaged.

The invention relates in particular to an injection device 2 arranged to connect in particular to the auxiliary pneumatic output OUT aux of the microfluidic device 1 so as to be able to benefit from a pneumatic force for injecting a fluidic sample into the microfluidic device 1.

The injection device 2 thus comprises a pneumatic network and a fluidic network. Two embodiments are proposed, a first mode in FIGS. 6A to 6C and a second mode in FIGS. 7A to 7C.

The injection device 2 comprises a housing 20 in which its fluid network and its pneumatic network are produced.

Without limitation, the housing can be of rectangular shape.

Its fluid network includes a reservoir 21 produced in an internal space of the housing and intended to receive a fluid sample 22 to be injected. It also includes a fluid outlet OUT2 through which the fluid sample is injected. A fluid outlet channel can connect the fluid outlet OUT2 to the reservoir 21.

The fluid output OUT2 can be arranged in a fluid connector arranged to cooperate with a corresponding connector in order to ensure a reliable and tight fluid connection. The connector in which the OUT2 fluid outlet is formed can be of the female type.

Its pneumatic network includes an IN2 pneumatic input. The pneumatic input IN2 is arranged in a pneumatic connector, suitable for connecting to the auxiliary pneumatic output OUTaux available on the microfluidic device 1. The connector in which the pneumatic input IN2 is formed can be of the female type.

The distance between the pneumatic inlet IN2 and the fluid outlet OUT2 of the injection device 2 and their respective positions are of course configured to be identical to those existing between the auxiliary pneumatic outlet OUT aux and the fluid inlet IN1 of the micro-device fluidics 1.

Its pneumatic network may include a pneumatic inlet channel 23 connected to its pneumatic inlet IN2 and intended to connect said pneumatic inlet to its fluid network so as to convey the pneumatic force to the fluid network.

This pneumatic inlet channel 23 opens into the reservoir 21, advantageously opposite the fluid outlet channel joining the fluid outlet OUT2.

The injection device 2 can also include a deformable membrane 24, forming a sealed interface between its pneumatic network and its fluidic network. This membrane 24 is for example arranged in the reservoir 21 and extends transversely relative to the direction of the pneumatic force generated at the interface between the pneumatic network and the fluidic network of the injection device. This membrane 24 is configured to deform during the exercise of a pneumatic force of sufficient intensity. By deforming under the action of said force, the membrane 24 pushes the liquid out of the reservoir 21 in the direction of the fluid outlet OUT2 of the injection device 2.

In a nonlimiting manner, like the membrane 12 of the microfluidic device described above, this membrane 24 can be made of an elastomeric material of the family of silicones such as MQ (Methyl-Polysiloxanes), VMQ (VinylMethyl-Polysiloxanes , PVMQ (Phenyl-Vynil-Methyl-Polysiloxanes) or elastomer of thermoplastic type (TPE), for example TPE-S, TPS, TPE-E, TPC.

Advantageously, the injection device 2 also includes one or more perforable or tear-off covers. It may be an adhesive film 25 deposited on the housing 20 of the device and arranged to seal the pneumatic inlet IN2 and the fluid outlet OUT2 of the injection device, thereby forming a barrier layer.

According to a particular aspect of the invention, the pneumatic inlet IN2 and the fluid outlet OUT2 of the injection device 2 are arranged in parallel and their opening sections, traversed by a gaseous flow (of air) for the pneumatic inlet and by a liquid flow for the fluid outlet, are produced in two parallel planes. Advantageously, the two planes are combined. In operation, the two planes will be arranged perpendicular to the axis (X). The pneumatic network and the fluidic network of the device are thus arranged so as to form an inverted U, the first branch of the U ending in the pneumatic inlet IN2 and the second branch of the U ending in the fluid outlet OUT2. The pneumatic inlet IN2 and the fluid outlet OUT2 thus open on the same face of the device or at least on two parallel faces. The pneumatic network and the fluidic network of the device are then arranged in the device to ensure the operation of the device, in particular the guiding of a pneumatic force towards the reservoir 21.

According to a particular aspect of the invention, when the injection device is filled with the fluid sample, it is injected by the fluid outlet OUT2 which then acts as an inlet. When filling, the pneumatic input IN2 of the device can be used to evacuate the air. As a variant, the pneumatic inlet IN2 can be used to aspirate the fluid sample inside the device by being connected to a pumping system having a connection adapted to that of the pneumatic inlet IN2 of the injection device. The film 25 for closing the pneumatic inlet and the fluid outlet is then bonded to the housing 20 of the device to finalize its preparation.

Without limitation, the injection device 2 can also have an architecture in which the opening sections of the pneumatic inlet and of the fluid outlet are no longer produced in two parallel planes, but in two inclined planes, one relative to the other, forming a single cavity, for example of conical shape, into which the pneumatic inlet and the fluid outlet open. This cavity is intended to cooperate with a corresponding protuberance of the microfluidic device on the blank of which opens its auxiliary pneumatic outlet and its fluid inlet.

Of course, it should be understood that any other architecture could be devised to make the connection between the injection device 2 and the microfluidic device 1.

In a nonlimiting manner, to pierce the film, the male type connector (located for example on the microfluidic card side) has a central protrusion making it possible to promote the drilling of the film 25, at the level of the pneumatic inlet IN2 and the outlet fluid flow OUT2 of the injection device.

FIGS. 6A to 6C represent the injection device without membrane and FIGS. 7A to 7C represent the injection device provided with a membrane 24.

With reference to FIG. 6A, without limitation, the injection device 2 can be produced by an assembly of several superimposed layers.

It may include a first substrate 40 in which the fluid network and the pneumatic network of the injection device are made in part.

The first substrate 40 has an initially planar upper face 400 (that is to say before machining of the fluidic network and the pneumatic network) and a planar lower face 401, perpendicular to the axis (X). It comprises a first cavity 402 produced on its upper face, for example of cylindrical shape of revolution, at the bottom of which a first channel 403 is produced in the direction of the axis (X) opening at its end in a second cavity 404 forming a flare opening on its underside 401.

The first substrate 40 also comprises a second channel 405 produced axially, from its upper face towards its lower face and opening into a third cavity 406 produced on its lower face 401.

A transverse channel 407 is also machined to provide the junction between the second channel 405 and said first cavity 402.

The injection device 2 comprises a second substrate 41 having a planar lower face 411 and a planar upper face 410.

The first substrate 40 and the second substrate 41 advantageously have a cross section of identical dimensions.

The second substrate 41 is fixed on the first substrate so that its lower face 411 comes to bear on the upper face 400 of the first card 40, covering the first cavity 402 to form the reservoir 21 of the device and the channels 405, 407 for form the pneumatic network.

After filling the device, as shown in Figure 6B, the film 25 can be affixed to obtain a pre-filled injection device ready for use (Figure 6C).

With reference to FIG. 7A, the injection device comprises a membrane 24 as described above. In this other configuration, the device comprises a first substrate 50. The first substrate 50 comprises an upper face 500 initially planar (that is to say before machining of the fluidic network and the pneumatic network) and a lower face 501 planar, perpendicular to the axis (X). It comprises a first cavity 502 produced on its upper face 500, for example of cylindrical shape of revolution, at the bottom of which a first channel 503 is produced in the direction of the axis (X) opening at its end in a second cavity 504 forming a flare opening onto its underside 501.

The first substrate 50 also comprises a second channel 505 produced axially from its upper face in the direction of its lower face and opening into a third cavity 506 produced on its lower face 501.

The membrane 24 is then fixed directly over the entire upper face 500 of the first substrate 50, closing off the first cavity 502. The membrane 24 is cut in the section of the second channel 505 to leave an opening.

The injection device 2 can then comprise a second substrate 51 comprising a planar upper face 510 and a planar lower face 511, and intended to be fixed by its lower face on the surface of the available membrane. This second substrate 51 has two through openings, a first opening 512 facing the opening formed through the membrane 24 and a second opening 513 opening onto the closed part of the first cavity 502 by the membrane 24. This substrate 51 also has on its upper face 510, a channel 514 arranged to provide the junction between the two openings 512, 513.

The device may finally comprise a third substrate 52 having an upper face 520 and a lower face 521. The third substrate 52 is fixed by its lower face 521 to the upper face 511 of the second substrate 51. It can be a simple adhesive membrane covering the substrate 51 and closing its channel 514.

The fluidic network and the pneumatic network of the injection device 2 can be machined according to methods known by the plastics industries such as mechanical machining with a numerically controlled machine, by 3D printing, or preferably by injection.

The material of each substrate 40, 41.50, 51, 52 can be selected from the following materials: polycarbonate polymer, PMMA, COC, silicon, and paper.

FIGS. 8A and 8B illustrate the operating principle of the injection device, respectively in its first embodiment and in its second embodiment described above. With the microfluidic device, the injection device forms a complete microfluidic system. In this example, the microfluidic device is chosen with the configuration of FIG. 1. Of course, the principle will be identical regardless of the microfluidic device to which the injection device 2 is connected.

Initially, the injection device 2 can be filled with the liquid sample during a filling step as described above. This step can be carried out during the manufacture of the device. Once the injection device is partially or completely emptied, it can be discarded.

Step E1 and E10

In this step, it involves connecting the injection device 2 to the microfluidic device 1. The pneumatic inlet IN2 of the injection device 2 and the fluid outlet OUT2 of the injection device 2 are thus connected respectively on the auxiliary pneumatic output OUT aux of the microfluidic device and on the fluidic inlet IN1 of the microfluidic device.

Step E2 and E11

During the connection, the protective film 25 is pierced to allow the fluidic and pneumatic connections to be established between the two devices.

For the first embodiment, in FIG. 8A, we then have:

Step E3

The auxiliary pneumatic input INaux of the microfluidic device 1 being connected to a pneumatic supply source 3, for example an air source, an air pressure (P) is applied through the auxiliary pneumatic input IN to the and the auxiliary output OUTaux of the microfluidic device.

By the connection made, the air is brought into the injection device 2 via its pneumatic inlet IN2.

The air pressure pushes the liquid present in the reservoir 21, through the fluid outlet OUT2 of the device.

The liquid crosses the fluid outlet OUT2 and enters the microfluidic device 1 via the fluid inlet IN1 thereof.

Step E4

The injection continues until the desired volume is injected into the microfluidic device 1. The source 3 thus remains active as long as the desired volume has not been injected.

The liquid injected into the microfluidic device can then continue its movement in the fluidic network of the microfluidic device 1, depending on the state of the microfluidic capsules of the device.

For the second embodiment, in FIG. 8B, we then have:

Step E12

The auxiliary pneumatic input IN aux of the microfluidic device 1 being connected to a pneumatic supply source 3, for example an air source, an air pressure (P) is applied through the auxiliary pneumatic input IN aux and the auxiliary output OUT aux of the microfluidic device.

By the connection made, the air is brought into the injection device 2 via its pneumatic inlet IN2.

The air pressure pushes the liquid present in the reservoir 21, through the fluid outlet OUT2 of the device.

The pressure is applied to the membrane 24 of the injection device. Under the effect of the pressure, the membrane 24 deforms and pushes the liquid outside of the injection device 2 via its fluid outlet OUT2.

The liquid crosses the fluid outlet OUT2 and enters the microfluidic device 1 via the fluid inlet IN1 thereof.

Step E13

The injection continues until the desired volume is injected into the microfluidic device 1. The source 3 thus remains active as long as the desired volume has not been injected.

The membrane continues to deform as long as the pressure in the tank increases.

The liquid injected into the microfluidic device can then continue its movement in the fluidic network of the microfluidic device 1, according to the state of the microfluidic capsules of the device.

The proposed injection device 2 thus has many advantages:

It does not require any particular actuation means, the actuation being carried out directly via the auxiliary pneumatic outlet of the microfluidic device;

It is easy to manufacture, by a simple assembly of layers;

It can be made of materials similar to those of the microfluidic device;

It is reliable and efficient, in particular thanks to the use of its membrane;

It is easy to use by a simple connection on the microfluidic device;

The connection solutions used allow a stable hold between the two devices, guaranteeing a perfect seal;

It allows to treat small volumes, thanks to the pneumatic control;

Claims (14)

1. Device for injecting (2) a fluid intended to be adapted on a microfluidic device (1) which comprises a fluidic network comprising a fluidic inlet (IN1) for receiving a fluidic sample and a pneumatic network comprising at least an auxiliary pneumatic input (IN aux) intended to be connected to a pneumatic power source (3) and an auxiliary pneumatic output (OUTaux) communicating with said auxiliary pneumatic input, said injection device comprising: A housing (20), A fluid network arranged in said housing (20) and which comprises a reservoir (21) arranged in an internal space of the housing and intended to receive said fluid sample (22) to be injected into said microfluidic device (1) and a fluid outlet (OUT2) connected to said reservoir (21) and arranged in a fluid connector adapted to connect in leaktight manner to said fluid inlet (IN1) of said microfluidic device to inject said fluid sample (22) into the fluid network of said microfluidic device , A pneumatic network arranged in said housing (20) and comprising a pneumatic inlet (IN2), - Characterized in that: Said pneumatic inlet (IN2) is arranged in a pneumatic connector suitable for sealingly connecting to said auxiliary pneumatic outlet (OUT aux) of said microfluidic device. 2. Injection device according to claim 1, characterized in that said device comprises at least a first face on which opens said pneumatic inlet (IN2) and a second face on which opens said fluid outlet (OUT2) and in that said first face and said second face are parallel. 3. Injection device according to claim 1 or 2, characterized in that it comprises an elastic deformable membrane (24) arranged in said reservoir (21) and forming a sealed interface for isolating the fluidic network from the pneumatic network. 4. Injection device according to claim 3, characterized in that the membrane (24) is made of a deformable material such as an elastomer of the family of silicones. 5. Injection device according to claim 1, characterized in that it comprises at least one film (25) arranged on said housing (20) for closing said fluid outlet (OUT2) and said pneumatic inlet (IN2). 6. Injection device according to one of claims 1 to 5, characterized in that said pneumatic network comprises a channel (23) connected to said pneumatic inlet (IN2) and opening into said reservoir (21). 7. Injection device according to one of claims 1 to 6, characterized in that said fluid network includes a channel connecting said reservoir to said fluid outlet (OUT2). 8. Injection device according to one of claims 1 to 7, characterized in that it is composed of an assembly of several superimposed substrates. 9. Microfluidic system comprising a microfluidic device (1) which comprises a fluidic network comprising a fluidic inlet (IN1) for receiving a fluidic sample and a pneumatic network comprising at least one auxiliary pneumatic inlet (IN aux) intended to be connected to a pneumatic power source (3) and an auxiliary pneumatic outlet (OUTaux) communicating with said auxiliary pneumatic inlet, characterized in that it comprises a fluid injection device (2) as defined in one of claims 1 to 8, said pneumatic inlet (IN2) of the injection device (2) being configured to connect to said auxiliary pneumatic outlet (OUT aux) of the microfluidic device (1) and said fluid outlet (OUT2) of the injection device (2) being configured to connect to the fluid inlet (IN1) of the microfluidic device (1). 10. System according to claim 9, characterized in that the pneumatic network of the microfluidic device (1) comprises a pneumatic control input (15) intended to be connected to a pneumatic power source (3). 11. System according to claim 10, characterized in that the fluidic network of the card comprises several fluidic valves actuable by said pneumatic network, via said pneumatic control input by which a pneumatic force is generated. 12. System according to claim 11, characterized in that each fluid valve comprises a microfluidic capsule (13) operable between a first closed state blocking the flow of a fluid and a second open state authorizing the flow of said fluid. 13. System according to claim 12, characterized in that the microfluidic device comprises at least one deformable membrane (12) arranged in each capsule (13) and actuable between two states by said pneumatic force. 14. Method for injecting a fluid sample into a microfluidic device (1) which comprises a fluid network comprising a fluid inlet (IN1) for receiving a fluid sample and a pneumatic network comprising at least one auxiliary pneumatic inlet (INaux) intended to be connected to a pneumatic power source (3) and an auxiliary pneumatic output (OUTaux) communicating with said auxiliary pneumatic input, said method being characterized in that it is implemented using a device injection (2) as defined in one of claims 1 to 8, the reservoir (21) of said injection device (2) comprising said fluid sample (22), and in that it comprises the following steps: Connection of the injection device (2) to the microfluidic device by connecting the fluid outlet (OUT2) of the injection device (2) to the fluid inlet (IN1) of the microfluidic device (1) and the pneumatic inlet (IN2) of the injection device (2) on the auxiliary pneumatic outlet (OUT aux) of the microfluidic device (1), - Connection of the auxiliary pneumatic input (IN aux) of the microfluidic device on a pneumatic power source (3), - Application of a pneumatic force through the auxiliary pneumatic input (IN aux) of the microfluidic device (1) and the pneumatic network of the injection device (2) so as to inject the fluidic sample (22) into the fluid network of the microfluidic device (1) via the fluid outlet (OUT2) of the injection device (2) and the fluid inlet (IN1) of the microfluidic device (1).