Distributor for microfluidic system

Abstract

The present invention relates to a flow distributor for a parallelized microfluidic chip system, adapted for the individual feeding of a large number of microfluidic channels. In particular, the invention proposes a distributor comprising at least one radial flow distribution channel, said channel having a central opening leading into peripheral openings distributed circularly around an axial center of said distributor, characterized in that: - the distributor comprises a support in the form of a regular cylinder, preferably circular, in which said at least one radial distribution channel is integrated, and such that - the peripheral openings are distributed on vertical walls of said support to convey a flow into or out of said distributor along a horizontal flow plane.

Description

Title of the invention: Distributor for microfluidic system TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of flow distributors. The invention finds particular applications in the distribution and collection of flows in microfluidic systems. STATE OF THE ART

[0002] Microfluidics is a technology that manipulates fluids in systems incorporating channels, at least one dimension of which is on the order of or close to the micrometer. In the field of liquid-liquid extraction, microfluidic channels allow two or more immiscible liquids to flow side by side in a laminar regime, and extraction to be achieved by the diffusion of molecules at the interface between the liquids. This results in an extraction system that maximizes the contact surface area between the liquids and allows for increased extraction yields with reduced solvent use.

[0003] Furthermore, this extraction process can be operated at ambient temperature, and therefore has a more favorable environmental footprint than conventional extraction processes, such as molecular distillation or conventional liquid-liquid extraction. Application WO2021 / 058806 provides an example of a microfluidic extraction process for refining vegetable oils and extracting biomolecules of cosmetic interest at ambient temperature and with a high extraction yield.

[0004] The drawback of microfluidic systems is the small quantity of liquid that can be processed within the microfluidic circuits. In order to increase productivity, it is common to use microfluidic chips integrating several microfluidic circuits operating side-by-side on a single substrate. However, the production capacity of these microfluidic chips is still insufficient for industrial or semi-industrial use. Therefore, the parallelization of microfluidic chips has been suggested as a solution to significantly increase their production capacity.

[0005] The operation of a parallelized microfluidic system involves supplying and collecting fluid from a plurality of microfluidic chips, each chip also integrating several microfluidic circuits. In a classical fluid distribution approach, for a linear arrangement of microfluidic chips, the main fluid inlet is split by a first three-port connector, dividing the main inlet into two paths. Each path is then brought closer to the microfluidic chip and the microfluidic channels to be supplied by means of the piping. The pipes are straight, possibly with fittings to direct the piping to the microfluidic chip to be fed, or additional branches to create more outlets and feed more microfluidic chips. This results in a piping system with varying lengths and / or branches depending on the positioning of the microfluidic chip relative to the main fluid inlet. The flow rates at the outlets will therefore depend on the pipe outlet and will not be uniform.

[0006] Radial flow distributors have therefore been proposed as a means of supplying and collecting microfluidic chips, so as to be able to more precisely balance the supply and collection flow rates of microfluidic systems. In this type of distributor, a central flow is divided homogeneously and radially into a plurality of outlets arranged in a circle and connected to the central opening by channels of similar characteristics.

[0007] EP 1 391 237 B1 patent gives an example of a chemical installation with five parallelized microfluidic chips for droplet production, implementing a radial flow distributor. In this system, each microfluidic chip incorporates a plurality of Y-type microfluidic channels, distributed circularly on a support disk to have a horizontal flow plane, but being fed and collected along a vertical plane. In particular, the microfluidic channel disk is sandwiched on one side by two distribution disks and on the other side by a collection disk. These distribution and collection disks allow a central flow to be radially divided into several peripheral outlets, or collected by reverse routing.The microfluid circuits are fed and collected by means of vertical conduits formed by overlapping perforations in the outlets of the distributor / collector discs, and in the inlets and outlets of the microfluidic channels.

[0008] This latter system allows for balanced flow sharing based on the number of inlets and outlets of a single disk incorporating a plurality of microfluidic channels. However, to increase the productivity of the microfluidic chip, it is suggested to stack several microfluidic channel disks. This results in unbalanced flow sharing because several microfluidic channels are fed and collected by means of the same peripheral outlets and shared vertical conduits. This type of distribution would therefore not be suitable for feeding and collecting a large number of microfluidic channels requiring high operational stability, such as in a laminar flow liquid-liquid extraction process.

[0009] It is therefore desirable to have flow distributors adapted to the supply and collection of a microfluidic system comprising several microfluidic chips operating in parallel, and requiring high operational stability. Description of the invention

[0010] The object of the present invention is to provide a flow distributor for a parallelized microfluidic system with laminar flow, adapted to the individual feeding of a large number of microfluidic channels. Another object of the invention is to have a distributor that facilitates the design and installation of a feeding and collection system for a parallelized microfluidic chip system.

[0011] To this end, the invention proposes a distributor comprising at least one radial flow distribution channel, said channel having a central opening leading into peripheral openings distributed circularly around a radius around an axial center of said distributor. The distributor of the invention is particular in that:

[0012] - the distributor comprises a support in the shape of a regular cylinder, preferably circular, in which said at least one radial distribution channel is integrated, and such that

[0013] - the peripheral openings are distributed on a cylindrical face of said support to convey a flow into or out of said distributor according to a horizontal flow plane.

[0014] Advantageously, this distributor allows a central flow to be divided into a large number of peripheral openings, thus enabling the individual and perfectly balanced supply and / or collection of a large number of microfluidic channels in a parallel microfluidic chip system. Furthermore, this distributor is designed to facilitate the installation and integration of said channels into such a microfluidic system.

[0015] In order to secure the connection to the microfluidic channels, and prevent the risk of leaks, the peripheral openings are respectively provided with hose connectors with fixing means.

[0016] The distributor is also designed to facilitate central feeding and collection. In particular, the central opening is provided with a connector opening onto an upper or lower face of said support and defining a central connection side 31 of said distributor.

[0017] The invention also proposes to control fluid resistance within said distributor. To this end, said at least one pipe (21a, 21b) has a first diameter DI at the central opening, and a second diameter D2 at the peripheral openings (22a, 22b), said second diameter being approximately one millimeter, such that its diameter is between 800 µm and 1500 µm.

[0018] and wherein said first diameter DI is greater than the second diameter D2 and decreases along said pipeline up to the level of the peripheral openings, and said second diameter D2.

[0019] The dispenser of the invention may also include one or all of the following features, in any technically feasible combination: - Said at least one pipe comprises a series of regular branches allowing the flow to be divided homogeneously into said plurality of peripheral openings, and each peripheral opening is connected to the central opening by means of a pipe circuit of identical length in said series of branches; - Said central opening is located in the center of a single conduit dividing in a first branch into two identical paths at each of its ends, and said plurality of peripheral openings is defined by said series of regular and successive branches from each of the resulting ends into two paths; - The distributor comprises two superimposed pipes at different heights of said support, and said pipes are superimposed in the distributor in a horizontal position with an angular offset, allowing the peripheral openings of said two pipes to be offset between them; - Said distributor comprises two pipes 21a, 21b superimposed at different heights of said support, and said pipes 21a, 21b are superimposed in the distributor in a horizontal position with an angular offset, allowing the positioning of the peripheral openings of said two pipes to be offset; - Both pipes have a connector on an upper or lower face of said support defining a central connection side 31 of said distributor.

[0020] The invention also relates to a distribution assembly comprising two or more superimposed distributors, said distributors being optionally raised by a lower support element.

[0021] Finally, the invention also relates to a microfluidic system comprising a plurality of microfluidic channels and a distributor according to the invention, said distributor being configured to supply and / or collect said plurality of microfluidic channels in parallel, and in which the peripheral openings of said distributor are connected by means of tubing and individually with inlets and / or outlets of said microfluidic channels. BRIEF DESCRIPTION OF THE FIGURES

[0022] Other advantages, purposes and particular features of the present invention will become apparent from the following non-limiting description of at least one particular embodiment of the devices, with reference to the accompanying drawings, in which: • Fig. 1 illustrates a distributor according to the invention incorporating two pipes integrated into a circular cylindrical support; • Figure 2 shows the details of the pipes integrated inside the distributor of the [Fig.l]. • Figure 3 shows two superimposed distributors forming a system central power supply and collection of a circularly parallelized microfluidic chip system. • Figure 4 shows an example of a microfluidic chip system circular parallelization and integrating the central feeding and collection system of the [Fig.3].

[0023] The present invention aims to provide a flow distributor for a parallel microfluidic chip system. The distributor of the invention has been designed to centrally supply and / or collect, under optimal conditions, a series of circularly distributed microfluidic chips.

[0024] The invention relates in particular to a distributor 200 ([Fig. 1]) comprising at least one radial flow distribution channel, said channel having a central opening leading into peripheral openings 22a, 22b distributed circularly around a radius around an axial center C of said distributor. This distributor is particular in that it comprises a cylindrical support 3 of regular shape, preferably circular, in which said series of radial distribution channels is integrated, and such that the peripheral openings 22a, 22b are distributed on a cylindrical face 32 of said support 3 to convey a flow at the outlet of said distributor along a horizontal flow plane.

[0025] This distributor 200 is specifically designed for a microfluidic system requiring a central feeding and collection system positioned at the center of a series of circularly distributed microfluidic chips, i.e., for a circularly parallel microfluidic system. Advantageously, the distributor of the invention is designed such that the peripheral openings 22a, 22b define outlets (or flow inlets) positioned on the cylindrical face 32 of said support and along a circular radius, which makes it possible to individually connect each opening with one of the inlets or outlets of the microfluidic channels that are located opposite said peripheral openings.

[0026] The cylindrical support 3 of the distributor facilitates the integration of several pipes according to a predefined arrangement, and distributes all the peripheral openings 22a, 22b at the level of the same circular radius of said support. The integration of each pipe 21a, 21b is easily achieved by positioning it at a desired height H within the cylindrical support 3. Each distributor can thus integrate several pipes 21a, 21b into the same support, simplifying the number of parts required for the installation of a central supply and collection system.

[0027] Figures 1 and 2 illustrate a preferred embodiment in which a distributor 200 incorporates two superimposed radial flow distribution channels 21a, 21b (visible in Figure 2). As illustrated in a simplified manner in Figure 1, the distributor 200 comprises a cylindrical support 3 with a circular base in which two superimposed radial flow distribution channels 21a, 21b are integrated at different heights H of said support 3. Each channel 21a, 21b is designed to have a number n of peripheral openings 22a, 22b equal to the total number of peripheral openings required to individually supply or collect all the microfluidic channels of a parallelized microfluidic system.Advantageously, this large number of peripheral openings is distributed along a cylindrical face 32 of said support and corresponding to a vertical and lateral wall of said support 3 in the operating position (according to said horizontal flow). In particular, the peripheral openings of each pipe are positioned in two rows at different heights of said support 3 and such that the distribution and flow of flux occurs along a horizontal plane, including at the peripheral openings 22a, 22b.

[0028] In the illustrated embodiment, the pipes are superimposed with an offset of approximately 5 degrees (360 / 64) for example, so as to offset the positioning of the peripheral openings of the upper pipe 21a and the lower pipe 21b relative to the positioning of the inlets of the double Y type microfluidic channels, and thus facilitate their connection with the latter.

[0029] Furthermore, the cylindrical support 3 has a central connection side 31, corresponding to its circular lower or upper face, and incorporating central connection connectors 3a; 3b linked with the central openings of the pipes 21a, 21b. The pipes 21a, 21b can thus be supplied or collected from only one side of the distributor. In particular, the central opening 20a of the first pipe 21a, located at the axial center of said distributor 200 and being closest to the central connection side 31, incorporates a straight connection (not shown) with the connector 3a. For its part, the central opening 20b of the second pipe, positioned below the first pipe, incorporates an angled connection between the connector 3b, which is offset from the axial center C of said support.

[0030] Each pipe 21a, 21b is completely independent of the other, so the distributor can be used to supply two different fluids. [Fig. 2] shows The details of the piping configuration according to a preferred embodiment, in which each piping 21a, 21b defines a conduit circuit having a central opening 20a, 20b located at the axial center C of said support, and opening into a single conduit, which divides radially into a series of progressive branches until opening into a plurality of peripheral openings 22, 22b. Advantageously, each piping 21a, 21b is configured to divide the central flow homogeneously into said plurality of peripheral openings, so as to be able to provide an identical flow rate at each peripheral opening 22a, 22b.

[0031] To this end, the single, straight, short conduit branches at its first junction into two paths at each end, each path having the shape of a circular arc and being connected at its apex to the single conduit. Each end of these paths then branches again into two paths also in the shape of a circular arc, and these ends branch again according to the same principle of branching into two paths respectively, and so on until the desired number of peripheral openings 22a, 22b is defined. In the illustrated example, each conduit has five series of circular-shaped branches from the straight single conduit, all branches being connected to the previous end at its apex, such that the ends of the final branches define sixty-four peripheral openings 22a, 22b. The shape of the branches is not limiting.

[0032] Since the pipe branches are perfectly regular, each peripheral opening (22a, 22b) will be connected to the central opening with a pipe of the same length as the other peripheral openings. The fluid resistances are therefore equivalent regardless of the flow path at the branches. Very precise flow control can thus be achieved to supply or collect several microfluidic circuits simultaneously.

[0033] As illustrated in [Fig. 2], the peripheral openings 22a, 22b have connectors for pipes or tubing, allowing the microfluidic circuits to be sealed to the distributor 200 by means of dedicated pipes or tubing. Advantageously, the connections include fastening means, allowing the connection to said pipes or tubing to be secured and enabling increased working pressures without risk of leakage. In one embodiment, the connectors are provided with a threaded hole for screwing onto a pipe or connectors for polymer tubing. The connectors are made of metallic material, or of an inert fluoropolymer material, such as silicone, or a fluoropolymer such as FEP (fluoroethylene propylene), PFA (perfluoroalkoxy), PEAK (polyaryletherketones), or PTFE (polytetrafluoroethylene). For its part, the dispenser is preferably made of plastic material. inert materials, such as PMMA, glass, or metal. Depending on the material chosen, the dispenser will be manufactured using a suitable microfluidic manufacturing process, such as: deposition and electrodeposition, engraving, bonding, injection molding, embossing, and photolithography.

[0034] The invention also proposes adapting the fluidic resistance at the level of the pipes 21a, 21b to gradually decrease it towards the peripheral openings 22a, 22b. The fluidic resistances within a duct or microduct depend on the dimensions of said duct and the viscosities of the fluids. In particular, the fluidic resistance is calculated as a function of the dynamic viscosity of the fluid (p), the length of the pipe (L) and the internal diameter of the duct (R) for a duct with a circular cross-section, or of the height (h) and width (w) dimensions for a rectangular cross-section:

[0035] Fluidic resistance for a pipe with a spherical cross-section = 8qL / (irR4 )

[0036] Fluidic resistance for a rectangular section pipe = (12pL) / (l-0.63(h / w) h3 w)

[0037] Regardless of the viscosity of the fluid to be distributed, the dimensions of the distributor's pipes will influence the resulting fluid resistances. The invention therefore proposes to progressively reduce an initial diameter DI of the pipes 21a, 21b, preferably at each branch, to obtain a final diameter close to one millimeter at the peripheral openings. The initial diameter will be a few millimeters, for example, between 3 and 10 mm. This makes it possible to adjust the fluid resistance to obtain a resistance close to that of the microfluidic circuit supply, and thus prevent a sudden increase in fluid resistance that could generate backflow phenomena.

[0038] In a non-limiting embodiment of the invention, the single conduit and the first series of branches have a diameter of 6 mm, subsequently reducing at each branch to 4 mm, 3 mm, 2 mm, and 1 mm at the peripheral openings. According to the illustrated embodiment, the conduits have a circular cross-section, but they can also have a square or rectangular cross-section.

[0039] As illustrated in [Fig. 3], the distributor 200 of the invention can be easily stacked with another distributor 200' thanks to its cylindrical support, the upper and lower circular faces of which are flat, with solid or partially hollowed surfaces as illustrated in the figures. Optionally, an additional support element S can be used to raise the distributors 200, 200' to a desired height. The stacking of two distributors, each incorporating two pipes, forms a distribution assembly enabling the implementation A central supply and collection system for a microfluidic system incorporating double Y-channels. Two channels are dedicated to supplying and collecting a first fluid, and two channels are dedicated to supplying and collecting a second fluid, as required in a liquid-liquid microfluidic extraction system with double "Y" type microfluidic channels. Of course, it will be possible to create distributors with more or fewer channels depending on the number of fluids to be supplied or collected from a given microfluidic system and the type of microfluidic channels integrated.

[0040] Figure 4 shows an example of a distribution assembly obtained by superimposing two distributors 200, 200' according to the invention, and its integration into a circularly parallelized microfluidic system 1 as a central supply and collection system. In this parallelized microfluidic system 1, a plurality of double Y-type microfluidic chips 10, 10' are arranged circularly around said central supply and collection system. Each microfluidic chip incorporates microfluidic channels that are individually connected to the peripheral openings 22a, 22b of the distributors by means of the tubing 4. The connectors at the peripheral openings 22a, 22b ensure the sealing of these connections and allow operation at relatively high pressures of up to more than 10 bar.In this example, the upper distributor 200 is used to distribute a hydroalcoholic solution via its first channel 21a, and an oil to be refined via the second channel 21b. The lower distributor is used to collect these two fluids from the outlet of microfluidic channels via its two channels 21a, 22b.

[0041] Advantageously, the central supply and collection are made from one side of the central connection 31 of the distributors 200, 200', the latter being able to be oriented as desired to facilitate the necessary connections. In the illustrated example, the sides of the central connection 31 are arranged with opposite orientations, so that the supply connections are made via an upper part of the system 1, and the collection connections via a lower part of said system.

[0042] The distributor of the invention thus allows central feeding and / or collection of a parallelized microfluidic chip system, and in this distributor all microfluidic channels can be fed and collected individually and under identical flow and fluid resistance conditions.

Claims

Demands

1. Distributor (200) for a parallel microfluidic chip system, comprising at least one radial flow distribution channel (21a, 21b), said channel (21a, 21b) having a central opening (20a, 20b) opening into peripheral openings (22a, 22b) distributed circularly around an axial center (C) of said distributor, wherein said at least one channel (21a, 21b) comprises a series of regular branches allowing the flow to be divided homogeneously into said plurality of peripheral openings, and wherein each peripheral opening (22a, 22b) is connected to the central opening (20a, 20b) by means of a channel circuit of identical length in said series of branches, characterized in that: - the distributor (200) comprises a cylindrical support (3) of regular shape, preferably circular, in which said at least a pipe (21a,21b) of radial distribution, and such that - the peripheral openings (22a, 22b) are distributed on a cylindrical face (32) of said support (3) to convey a flow into or out of said distributor and of said at least one conduit along a horizontal flow plane.

2. Distributor according to claim 1, wherein the peripheral openings are respectively provided with hose connectors with fixing means.

3. Distributor according to claim 1 or 2, wherein said central opening (20a, 20b) is connected to a central connection connector (3a, 3b) opening onto an upper or lower face of said support and defining a central connection side (31) of said distributor.

4. Distributor according to any one of the preceding claims, wherein said at least one conduit (21a, 21b) has a first diameter DI at the central opening (20a, 20b), and a second diameter D2 at the peripheral openings (22a, 22b), said second diameter being approximately one millimeter, such as a diameter between 800 pm and 1500 pm, and in which said first diameter DI is greater than the second diameter D2 and decreases along said pipeline (21a, 21b) up to the level of the peripheral openings (22a, 22b), and said second diameter D2.

5. Distributor according to claim 4, wherein said central opening (20a, 20b) is located in the center of a single conduit dividing in a first branch into two identical ways at each of its ends, and said plurality of peripheral openings (22a, 22b) is generated by said series of regular and successive branches from each of the resulting ends into two ways.

6. Distributor according to any one of the preceding claims, wherein said distributor comprises two superimposed pipes (21a, 21b) at different heights (H) of said support, and said pipes (21a, 21b) are superimposed in the distributor in a horizontal position with an angular offset, allowing the respective peripheral openings (20a, 20b) of said two pipes (21a, 21b) to be offset between them.

7. Distributor according to claim 6, wherein the two channels (21a, 21b) have central openings (20a, 20b) connected respectively to a central connection connector (3a, 3b) on an upper or lower face of said support, and defining a central connection side (31) of said distributor.

8. Distribution assembly comprising two or more distributors (200, 200') superimposed according to any one of claims 1 to 6, said distributors being optionally raised by a lower support element (S).

9. Microfluidic system (1) comprising a plurality of microfluidic channels and a distributor (200) according to any one of claims 1 to 7, said distributor (200) being configured to supply and / or collect in parallel said plurality of microfluidic channels, and in which the peripheral openings of said distributor are connected by means of tubing and individually with inlets and / or outlets of said microfluidic channels.