EP1515794A1

EP1515794A1 - Hydraulic device for the thermo-pneumatic insulation and optional agitation of the contents of an operative cavity

Info

Publication number: EP1515794A1
Application number: EP03760784A
Authority: EP
Inventors: Yves Fouillet; Patrick Pouteau; Nicolas Sarrut; Dominique Masse; Frédéric Ginot
Original assignee: Biom Rieux; Commissariat a lEnergie Atomique CEA
Current assignee: Biomerieux SA; Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2002-06-24
Filing date: 2003-06-24
Publication date: 2005-03-23
Also published as: FR2841158B1; AU2003253079A8; JP2005530608A; AU2003253079A1; CN100377770C; CN1671467A; US20050196328A1; FR2841158A1; WO2004000449A1

Abstract

The invention relates to hydraulic device (1) produced from one or several components, for example from a support (12) comprising: an operative cavity (3), at least two ducts (41, 42), for example an inlet (41) and outlet (42) for a liquid of interest which communicate with said operative cavity (3), at least two valve bodies (51, 52) with no moving pieces for control of said cavity. The above is characterised in that said device further comprises two trapping chambers (81, 82) for a gas, for example, air, in communication only and respectively with the two ducts (41, 42), by means of two connecting channels (91, 92) respectively, both pertaining to thermal exchange with a heat source (21, 22).

Description

Fluidic device for thermo-pneumatically isolating and possibly agitating the contents of an operating cavity

The present invention relates to a fluidic device comprising or associated with an operating cavity of the reactor type, allowing, without any mechanical or moving part, on the one hand to isolate the contents of said cavity, and on the other hand to isolate with agitation. of the contents of this cavity.

More particularly, the invention relates to a fluidic device of the microfluidic type, usable by way of example in systems or device of the "laboratory on chip" type (in English "lab-on-a-chip"). Today, for various medical, pharmaceutical, biological and chemical applications, microfluidics is a developing technical field. To simplify, it is a question of treating liquids, gases, and solids if necessary, in devices or structures whose volume unit is between 1 nano liter and 1 microliter. On this scale, it is therefore required or preferred to exclude any part of the mechanical type, in particular with a moving part, and by way of example the thermo-pneumatic is retained as the actuation or motor principle, in particular for the circulation of liquid in such systems.

The main functions required on a much higher scale to treat liquids and gases have been designed and developed to be adapted to the micro-fluidic scale.

As regards first of all valves or valves, or more generally means allowing any control of the flow rate of a liquid, various solutions using gas or vapor microbubbles have been proposed. By way of example, reference is made to the following publications:

A) Y.S-Leung Ki, M.Kharouf, HTG Van Lintel, M. Haller, Ph. Renaud, Bubble Engineering Valving applications, IEEE-EMBS, 200,390-393 B) Alexandros P. Papavasilliou, Doran Liepmann, Albert P. Pisano,

Electrolysis-Bubble Actuated Gâte Valve, Solid-State Sensor and Actuator Workshop, 2000, 48-51 As regards the pumping function of a liquid and more generally the increase in the pressure of a said liquid, the following publications may be cited by way of example:

C) Jr-Hing Tsai and Liwei Lin, A thermal bubble actuated micro nozzle-diffuser pump, 14th IEEE Inter.Conf. On MEMS 2001, 409-412

D) K. Handique, D.T. Burke, C.H. Mastrangelo, and MA Burns, On-Chip thermopneumatic pressure for discrète drop pumping, Analytical chemistry, Vol. 73, n ° 8, 2001, 1831-1838; cf. US-C-6 130 098 and US-A 2002/01 0492 As regards also the mixture of two components, and for example of two liquids, reference will be made to the following work:

E) Wolfgang Ehrfeld, Wolker Hessel, Holger Lowe, Microreactors, New Technology for Modem Chemistry, Wiley-VCH, 2000,41-83.

In accordance with US-C-6 193 471, a fluidic device has been described making it possible to form and transport predetermined volumes of a liquid. To this end, according to an embodiment described with reference to Figure 7, there is a fluid section comprising, in series, a reserve chamber, a first storage cavity, a portion of capillary conduit, and a second storage cavity. The reserve chamber and the two storage cavities are in communication with an external pressure source. To form and transport a predetermined volume of liquid:

- From the reserve chamber, the portion of capillary conduit is filled with liquid, through the first storage cavity, and stopping at the second storage cavity; the portion of capillary conduit between the two storage cavities defines the predetermined volume of liquid,

- by increasing the pressure in the first storage cavity, the liquid is returned to the reserve chamber, by isolating the predetermined volume of liquid between two menisci situated respectively at the level of the two storage cavities, - by increasing the pressure in the first storage cavity, the predetermined and isolated volume of liquid is transferred beyond and through the second storage cavity.

In accordance with US-C-6 193 471, the formation and the transport of an isolated volume of liquid are obtained by the differentiated control from the outside of a pressure, respectively in the reserve chamber and in the cavities storage, these particularly complex control means being represented for example by reference to FIGS. 13 and 14.

In accordance with US-C-4 676 274, a microfluidic device is described, consisting of an arrangement of capillary conduits, comprising different capillary valves, without moving part, each arranged to generate an overpressure at the interface between a control gas and a liquid of interest, or meniscus. By external control of the control gas, to or from the fluidic device, at the level of the various capillary valves, it is possible to circulate, or "pump", the liquid of interest according to any predetermined process. In accordance with US-C-6 117 396, a microfluidic device has been described making it possible to dispense predetermined volumes of a liquid of interest, from a single inlet conduit, thanks to an external source gas, injected into said device to move said predetermined volumes. In a microfluidic device of the type of those previously defined or described, the present invention relates specifically to the following function, namely the isolation in an operating cavity of a volume of liquid filling it, possibly with agitation of said volume in said cavity. The object of the present invention is to achieve this function with particularly simple fluidic means.

To this end, a fluidic device according to the present invention, arranged from one or more components, for example from a support comprises: - an operating cavity

- at least two conduits, for example inlet and outlet of a liquid of interest, communicating with the operating cavity, respectively by means of two bodies without moving part, of the valve type, allowing the control of the cavity operating - two trapping chambers for a gas, for example air, communicating only and respectively with the two conduits, by two separate connection channels respectively of the two said conduits

- Heat exchange means with one and / or the other trapping chamber, in order to control the gas pressure in one and / or the other said trapping chamber. Consequently, according to the present invention, on either side of the operating cavity, an inlet or outlet conduit and a connecting channel with a trapping chamber communicate, directly or indirectly, with the same member without moving part, of the valve type, placed on the operating cavity. In other words, a said connecting channel is connected to an inlet or outlet conduit, for example by means of an expansion chamber, as described or defined below.

By way of example, the conduits considered by the present invention are capillary, in the sense that, with respect to a predetermined liquid, they are capable of containing the latter according to a certain height against gravity. By way of illustration, such conduits have a section whose transverse dimension (or diameter) does not exceed 1.5 mm, for example of the order of 500 μm.

When, according to the present invention, a "cavity" or "chamber" is envisaged, the shape and / or the dimensions of the latter differentiate it from a duct, in the sense that by following a dimension, for example in the direction liquid circulation, or the other dimensions of the cavity or chamber are greater than that, for example transverse, of a conduit.

A device according to the present invention constitutes, by means of the trapping chambers, a thermo-pneumatic system, in the sense that only thermal actuations make it possible to control the pressure and / or the volume of the gas in the trapping chambers.

Preferably, the device comprises, on either side of the operating cavity, two isolation means disposed respectively on the two conduits, for example inlet and outlet, each arranged to take two positions, namely a position establishing a communication of a said conduit with the outside, and another position isolating said conduit from the outside. By isolating the device from the outside, thanks to the two isolation means in the closed position, said device becomes a closed thermodynamic system, in particular with respect to the gas it contains, trapped in the trapping chambers.

Preferably, a device according to the present invention comprises two expansion chambers each disposed between said operating cavity and each conduit, each chamber communicating on one side with said conduit by a first capillary valve with no moving part, opposing any liquid passage capillary, opposing any liquid passage to said chamber, and on the other side with said cavity by a second capillary valve, opposing any liquid passage to said chamber.

For example, the two connecting channels each connect a trapping chamber with an expansion chamber. And each expansion chamber constitutes the junction between an inlet or outlet conduit and a connecting channel with a trapping chamber, on each side of the operating cavity.

The means for controlling the pressure and / or the volume of the gas in one and / or the other trapping chamber are: - two hot sources in heat exchange relationship with the two trapping chambers respectively, - or one only hot source, in heat exchange relationship with the two trapping chambers.

By "hot source" is meant any source capable of delivering and / or receiving heat.

Each of these hot springs can be a resistance integrated on the cover of the fluidic device, for example a platinum resistance produced by photolithography, on a glass cover, aligned opposite one or the other of the trapping when assembling the cover with the support. This resistance can be of the order of 25 to 50 ohms.

Each of these hot sources can be an emitter of radiation, for example infrared radiation, capable of being absorbed by the gas present in the trapping chambers.

According to another embodiment, it may be advantageous to have only a hot source, alternately arranged opposite one then the other trapping chamber.

The present invention is now described with reference to the accompanying drawing, in which: FIG. 1 schematically represents a fluidic device in accordance with the present invention; Figures 2 and 3 show, still schematically, two phases of use of the device according to Figure 1, to isolate or confine a volume of a liquid of interest in the operating cavity, belonging to said device; - Figures 4 to 6 show schematically respectively three embodiments of any capillary valve belonging to a device according to the invention, and by way of example disposed at the junction between a connecting channel and an expansion chamber belonging to the device according to FIG. 1;

- Figures 7 and 8 respectively represent two phases of use of the device shown in Figure 1, to agitate the contents of the operating cavity belonging to said device.

- Figures 9 to 11 show another embodiment called "threshold", of an expansion chamber belonging to a device according to Figure 1, Figures 9 to 11 schematically and respectively representing three phases of thermal control d 'such an expansion chamber;

- Figure 12 shows an embodiment of the operating cavity of a fluidic device according to the present invention;

FIG. 14 represents a device according to the present invention, modified to implement the immunoassay format shown diagrammatically in FIG. 13.

In accordance with FIG. 1, a device according to the invention is produced by means of micro-technologies, making it possible to obtain, in any flat support, for example a hollow structure represented schematically on a large scale in FIG. 1. Among these micro -technologies, one can cite chemical etching or with a plasma of a silicon or glass support, machining, hot molding ("hot-embossing"), and injection or ablation by laser beam d 'a flat support, for example plastic, such as polycarbonate. In practice, we start from the flat support; from one of these faces, the hollow structure shown schematically in FIG. 1 is obtained, and the latter is sealed, with sealing, by means of at least one closure plate or film coming opposite the face of the support in which the hollow structure was made, and sealed or glued against said support, an appropriate covering covering the assembly if necessary.

In general, with reference to FIG. 1, the hollow structure defines in the support (12) a fluidic device (1) comprising:

- an operating cavity (3) or micro-reactor,

- at least two conduits (41, 42), for example inlet (41) and outlet (42), of a liquid of interest (not shown in this figure), communicating indirectly with the operating cavity (3) , - two trapping chambers (81) and (82) of a gas, for example air, communicating respectively, only and indirectly with the two conduits (41, 42), by the two expansion chambers (61) and (62) defined below and two connecting channels (91, 92) respectively, the two chambers (81 and 82) being in relation to 'heat exchange each with a hot source (21, 22), - two expansion chambers (61) and (62), each disposed between said operating cavity (3) and each conduit (41) or (42), each chamber communicating on one side with a said duct (41) or (42) by a first capillary valve (71) or (72), that is to say a valve without moving part, of the capillary restriction type, opposing any liquid passage to said expansion chamber, and on the other side with the operating cavity (3), by a second capillary valve (51) or (52), as defined above, opposing any liquid passage to the expansion chamber,

- the two connecting channels (91, 92) each connecting a trapping chamber (81) or (82) with an expansion chamber (61) or (62), - two capillary valves (101) and (102) such as defined above, by which the connecting channels (91, 92) communicate respectively with the corresponding expansion chambers (61) and (62), these two capillary valves opposing any liquid passage towards the trapping chambers (81 ) and (82) respectively, - two isolation means (201 and 202), disposed respectively on the two conduits (41 and 42), on either side of the operating cavity (3), each arranged to take two positions, namely an open position establishing communication of a said conduit with the outside, and a closed position isolating said conduit from the outside. By “capillary valve”, and by reference by way of example to the valve represented in an enlarged manner under the reference (71) in FIG. 3, is meant a valve without moving part, constituted by a capillary type restriction, opposing at any liquid passage in a given direction, for example towards the expansion chamber (61) relating to the valve (71), in FIG. 3. In practice such a capillary valve is arranged to generate an interface between a gas, for example residual air, and a liquid, for example the liquid of interest, interface called in meniscus practice, the latter generating an overpressure generally opposing any liquid passage beyond the valve, of course below a given pressure, or pressure threshold. In practice, the obtaining and the reproducibility of such a meniscus depend on many factors, among which may be mentioned: - the geometry of the edges or walls at which the meniscus is obtained,

the wettability of the liquid, and / or its surface tension with respect to the material constituting said edges or walls, any appropriate treatment of the latter, for example of the hydrophobic or hydrophilic type, being in particular capable of modifying the above-mentioned properties. -vis liquid.

As shown by way of example in FIG. 1, but also in the enlargement of FIG. 3, it is the relative geometry of the edges or walls which is used to generate any capillary valve as defined previously functionally.

In practice, taking into account the microtechnologies used, the operating cavity (3) constitutes for example a micro-reactor, having a volume of the order of 0.1 μl, the expansion chambers (61) and ( 62) having a volume of the order of 0.03 μl, as well as the trapping chambers (81) and (82) having a volume of the order of 0.03 μl to 0.15 μl.

In practice, a fluidic device 1 as described above is also suitable (but not shown) for working in a technical environment providing it:

- Heat and / or cold, to heat and / or cool, on the one hand the entire device 1, and optionally separately the trapping chambers (81) and (82) by heat sources and / or cold (21) and (22) in heat exchange relationship only and respectively with said chambers (81) and (82)

- a pressure or load, at the outlet of the device, for example in the outlet duct (42)

a source of pressure or load, at the inlet of the device, for example in the duct (41), generally greater than the outlet pressure, for example in the duct (42), and this by any appropriate means, such as that a height of liquid higher than the height of liquid at the outlet of said device, for example in the case of filling under pressure, or by a syringe, itself mounted on a syringe pump.

During the active operating phase of a device according to the invention, that is to say the isolation of the operating cavity filled with the liquid of interest, with or without agitation, said device is isolated from the outside by means 201 and 202, in the closed position, and constitutes a closed system in heat exchange with the sources 21 and / or 22. By construction, depending on the support (12), the geometry and the size of the fluidic device (1), the person skilled in the art will retain and adjust numerous parameters, in order to obtain stable and reproducible operation of said device. These parameters include: - the wettability of the liquid or liquids used relative to the internal surface of the device, considered in particular by its geometry and its surface characteristics,

- the external pressures upstream and downstream of the device, that is to say at the level of the inlet (41) and outlet (42) conduits respectively, - the temperatures and the heat exchanges, as well as their control between the different parts of the device.

The shape of the operating cavity (3) can be optimized depending on the intended application. The capillary shape, shown in Figure 12, may be of interest for certain chemical reactions; this form appears to be suitable for good stirring of the liquid of interest, in order to obtain a more homogeneous or more complete reaction.

The previously described device is now used to isolate or confine the contents of an operating cavity (3), according to the operation described below. At the start, the device (1) is empty, and the isolation means

(201 and 202) in the open position, as shown in FIG. 2. It is therefore, for example, naturally filled with ambient air, under atmospheric pressure, or under higher pressure, depending on the inlet and outlet pressures. of the device, as indicated previously. Preferably, by forced circulation, for example by means of an external pump, of the liquid of interest, from the inlet duct (41) to the other outlet duct (42), the operating cavity (3) is filled ) and the expansion chambers (61) and (62), retaining a residual gas and therefore ambient air in the two trapping chambers (81) and (82). The ambient air is therefore trapped in the chambers (81) and (82) at a so-called filling temperature, identical or different from the ambient temperature, and at a pressure substantially equal to the outlet pressure, i.e. - say that available in the conduit (42).

Given the capillary valves (101) and (102) described above, resulting from the construction of the device according to FIG. 1, the liquid present in the expansion chambers (61) and (62) is prevented from entering in the connecting channels (91) or (92) to the trapping chambers (81) and (82) respectively.

Figures 4 to 6 describe different possible forms of capillary valve. Figures 4 and 5 illustrate a narrowing of the capillary section in the case of a wetting liquid. Conversely, in the case of a non-wetting liquid, it is a widening of the section of the capillary which allows blocking of the meniscus at the level of the valve (cf. FIG. 6).

The overpressure thus obtained at the level of a capillary valve as previously described makes it possible to have a lower requirement on the value of the pressure to be applied to the residual gas.

The capillary valve (101) or (102) can be arranged according to one of the embodiments shown schematically in Figures 4 and 5 respectively. According to Figure 4, a baffle (95) is arranged obliquely at the base of the connecting channel (91) and (92), directed towards the corresponding trapping chamber (81) or (82). According to Figure 5 a restriction is provided at the base of the connecting channel (91) or (92).

After circulation of the liquid of interest, the state of the device shown in FIG. 2 is therefore obtained, in which the conduits (41) and (42), the expansion chambers (61, 62) and the operating cavity (3 ) are met. The device is then isolated, by placing the isolation means (201 and 202) in the closed position, as shown in FIG. 3.

Then the residual gas in the two trapping chambers (81) and (82) is brought to a so-called isolation temperature, higher than the previously called filling temperature, in order to bring the pressure in the trapping chambers (81) and ( 82) at a value sufficient to completely evacuate the liquid of interest from the two expansion chambers (61) and (62), by the two conduits (41) and (42) respectively. Consequently, the expansion chambers (61) and (62) are filled with two bubbles of residual gas, isolating the operating cavity (3), from any leakage of the liquid of interest, and / or of any diffusion of the particles contained in said liquid of interest, towards the conduits (41) and (42), or from said conduits (41) and (42) towards said cavity (3).

Throughout the description, "particle" means any discrete element, for example an element carrying biological information, such as an electrically charged, magnetic, or non-magnetic particle, supporting a biological molecule. This results in the state of the device shown in FIG. 3, in which the operating cavity (3) and the conduits (41) and (42) are filled. In this state, the liquid is prevented from entering from the conduits (41) and (42), by virtue of the capillary valves (71) and (72) previously described, naturally existing by construction of the device, or specifically arranged for this purpose. In the same way, from the operating cavity (3), the liquid is prevented from entering the expansion chambers (61) and (62), respectively thanks to the capillary valves (51) and (52).

This isolation step can be carried out in different ways:

either the entire device is heated to the so-called isolation temperature, and in such a case the two bubbles of the residual gas are formed simultaneously in the chambers (61) and (62),

- Either one after the other is heated, the trapping chambers (81) and (82) respectively with the hot springs (21) and (22), and the two bubbles of the residual gas are obtained one after the other. other, in the expansion chambers (61) and (62),

- Either the entire device is heated, in particular for the implementation of a chemical reaction within a reaction mixture in the operating cavity (3), and additionally heated, one after the other the trapping chambers (81) and (82).

Regarding the trapping chambers (81) and (82), they are dimensioned so as to initially contain a volume of the residual gas, which, heated to the so-called isolation temperature, completely or partially occupies the expansion chambers ( 61) and (62) respectively. Furthermore, these same chambers (81) and (82) have a compensating role, when the liquid rises naturally towards them, when the device cools, to a temperature possibly lower than the filling temperature. As soon as the temperature increases, the liquid returns, without capture inside the chambers (81) and (82), to the expansion chambers (61) and (62) respectively.

It is understood that the use of the fluidic device (1), for the purpose of isolating or confining an operating cavity (3), described above, can be made without expansion chambers (61) and (62). According to the preceding description, in a particularly simple manner, and in particular by a purely thermo-pneumatic actuation, in particular thermodynamic of the device, it is therefore possible to isolate a reaction mixture against the diffusion towards the outside of any particles or species which it contains. Thanks to this confinement, the concentration of the reaction mixture is not modified, which may be essential for the yield and the integrity of the reaction carried out.

We will now describe the use of the same fluidic device (1) to agitate the contents of the operating cavity (3). For such use:

the two expansion chambers (61) and (62) are substantially identical, in particular in volume, - the two trapping chambers (81) and (82) are substantially identical, in particular in volume,

- And the two trapping chambers (81) and (82) are heated locally and independently thanks to the hot springs (21, 22) respectively. As already described with reference to FIG. 2, previously, by circulation of the liquid of interest from the inlet duct (41) to the other outlet duct (42), the operating cavity (3) is filled and the two expansion chambers (61) and (62), retaining the residual gas in the two trapping chambers (81) and (82), at a predetermined temperature, previously called filling. The device is therefore in the state shown schematically in FIG. 2.

The device (1) is isolated with the means (201 and 202) in the closed position.

From the filling temperature, the temperature of the residual gas in one (81) and in the other (82) of the trapping chambers is increased to a reference temperature; this increase in temperature in the chambers (81) and (82) is preferably simultaneous. However, the reference temperature in the trapping chamber (82) has a high value, greater than the so-called low value, in the other trapping chamber (81). Due to this difference in reference temperatures, respectively in the chambers (81) and (82), the expansion chamber (62) is completely filled with a bubble of the residual gas, while the expansion chamber (61 ) is partially filled with the same residual gas. Consequently, on the one hand a discrete portion (20) of the liquid of interest remains in the expansion chamber (61), and on the other hand the residual gas is compressed on the side of the expansion (61) and trapping (81) chambers. This results in the state of the device shown in FIG. 7.

Between the states of the device (1) shown in Figures 2 and 7 respectively, the volume of liquid of interest displaced has flowed to the inlet (41) and / or outlet (42) conduits. If necessary, the residual gas present in the trapping chamber (81) can be heated, then the residual gas present in the trapping chamber (82), which facilitates the evacuation of the liquid towards the outlet conduit (42).

Then the temperature of the residual gas in the other trapping chamber (81) is increased by an increment Δ t, from the reference temperature previously reached, while the reference temperature in the trapping chamber (82) is not changed. It is of course possible to simply reverse the heat exchanges of the heat sources (21,

22) to achieve the same result. Consequently, on the one hand, the portion (20) of the liquid of interest is displaced, from the operating cavity (3) towards the expansion chamber (62) associated with the trapping chamber (81), thus being discharged from the expansion chamber (61), and on the other hand the residual gas is compressed in the expansion chamber (62).

This results in the state of the device shown in Figure 8. This cooling can be advantageously obtained naturally, by simple convection and heat dissipation, since the fluidic device according to the invention has very small dimensions.

Then the temperature of the residual gas in the other (81) of the trapping chambers is brought back to the so-called reference temperature, at its low value, by means of which the same proportion (20) is displaced towards the expansion chamber (61) associated with said trapping chamber (81), to find the state shown diagrammatically in FIG. 7.

The operations described above can be generated an integer number of times, to generate oscillations of the discrete portion (20) on either side of the operating cavity (3). These oscillations can be obtained at frequencies from 0.5 Hz to 25 Hz. They can be caused over a period of the order of an hour, corresponding to the duration of the chemical (or other) reaction in the operating cavity ( 3).

Consequently, the fluidic device (1) according to FIG. 1 can be used, to isolate or confine and stir all or part of a liquid of interest at the level of the operating cavity (3), according to the following operating steps: a) beforehand, by circulation of the liquid of interest, from an inlet conduit (41) to the other outlet conduit (42), the operating cavity (3) and the expansion chambers ( 61, 62), retaining a residual gas in the two trapping chambers (81, 82), b) after circulation of the liquid of interest, the residual gas is brought in the two trapping chambers, to a temperature called isolation, to bring the pressure in said trapping chambers to a value called equilibrium pressure, sufficient to evacuate all or part of the liquid of interest from the two expansion chambers (61, 62) by at least one of the two conduits ( 41, 42), and fill all or part of said chambers with two bubbles of the residual gas, isolating the operating cavity from any leakage of the liquid of interest and / or from any diffusion of the particles contained in said liquid interest towards said conduits (41, 42), c) the temperature of the resi duel present in at least one of the trapping chambers (81, 82), in order to modify its pressure and move the liquid of interest towards one of the expansion chambers (61, 62), without breaking the isolation of the operating cavity (3), d) the temperature of the residual gas present in at least one of the trapping chambers (81, 82) is again modified in order to modify its pressure again and move the liquid of interest towards the other of the expansion chambers (61, 62), without breaking the isolation of the operating cavity (3). The pressure obtained in step (d) is the equilibrium pressure. Preferably, steps (c) and (d) are repeated. The operations described above can be generated an integer number of times, to generate oscillations of the discrete portion (20) on either side of the operating cavity (3), through the latter, the residual gas being compressed in each direction, or in the expansion chamber (62) or in the expansion chamber (61), and exerting each time a return action in the opposite direction. As previously described with reference to FIGS. 1 to 3, it is observed that not only a stirring function is obtained, but also an isolation function, since the volume of the liquid of interest, present in the operating cavity (3 ) is isolated, with the discrete portion (20) of the same liquid, generally representing a few% of the volume of the operating cavity (3). In particular, the capillary valves (71, 72, 51, 52, 101 and 102) play exactly the same role in the agitation function as in the pure isolation function.

Thanks to the same capillary valves, the residual gas is compressed, without being able to flow, either towards the inlet duct (41) or towards the outlet duct (42). Thus the residual gas can play a damping role in the agitation function described above.

The proportion (20) of the liquid of interest is determined by the association of the geometry of the expansion chambers (61) and (62), and the choice of the so-called stirring temperatures previously exposed. As shown in Figures 9-11, the expansion chambers

(61) or (62) can have a predetermined geometry, in order to obtain a so-called "threshold" structure.

According to these figures, each expansion chamber (61) or (62) comprises, in the direction of the operating cavity (3), two successive narrowing A and B, towards diameters or sections respectively smaller than one another. Consequently, from a complete filling of the expansion chamber (61) according to FIG. 9, in order to pass to a complete evacuation, it is necessary to increase the temperature in a non-linear manner, according to two stages or thresholds, taking into account the increase in the capillary force from one narrowing to the other, at the interface or meniscus between the liquid of interest and the residual gas. These allow a discrete volume variation, or in stages, and therefore a more flexible thermal control of the fluidic device according to the invention, either in isolation, or in agitation or both. Of course, the agitation previously described with reference to Figures 7 and 8 can be obtained with amplitudes and frequencies previously selected. It intervenes locally in the device, and does not require the introduction of particles or other means, since only the residual gas, trapped passively during filling with the liquid of interest is the only means used for this purpose, and this on the periphery or outside of the isolated liquid of interest.

In total, thanks to the fluidic device according to the invention, it is possible, in a particularly simple manner, and only with thermal or other control, to obtain both, either isolation in the operating cavity (3) against any leakage of said liquid and or diffusion of particles to the outside, the same isolation but with agitation. A fluidic device as previously described or defined is particularly well suited for the implementation of a method, of ELISA or ELOSA type, for determining a target species, or analyte, described schematically below with reference to the figure 13. According to this method, it is a question of determining, namely of qualitatively and / or quantitatively detecting, a target species, or analyte (C) comprising two ligation sites (C1, C2) respectively with a first ligand (L1) , and with a second ligand (L2) linked directly or indirectly to a marker E. To this end, the method comprises the following steps: a) there is a support (Mi) functionalized with the first ligand (Li) placed by example in liquid medium, in an incubation chamber (not shown), b) always in liquid medium, in the incubation chamber, the functionalized support (Mi, L1) is brought into contact, successively or simultaneously, l target species (C) or ana lyte, and the second labeled ligand (L ₂ , E), to obtain a complex 300 associating the support (Mi), the first ligand (Li), the target species (C) and the second labeled ligand (L ₂ , E ), c) there is, for example in a liquid medium or in contact with a liquid medium, another support (M ₂ ) functionalized 303 with a third ligand (L ₃ ), capable of binding to the target species (C), d) the complex 300 is associated in an oriented manner, to separate a conjugate 301 associating the target species (C) and the second labeled ligand (L2, E), from the functionalized support 302 (M1, L1), e ) in liquid medium, the other functionalized support 303 (M _2> L ₃ ) is brought into contact with the conjugate 301, to obtain another complex 304 associating the other support (M ₂ ), the third ligand (L ₃ ) , the target species (C) and the second labeled ligand (L ₂ , E). f) the marker E of the other complex (304) is detected qualitatively and / or quantitatively.

This generally defined process of the immunoassay type can be subject to various adaptations or supplements, in particular depending on the analyte (C), or the device allowing its implementation. Thus: - the third ligand (L ₃ ) can be identical to or different from the first ligand (Li), step e) can be carried out in an identical or different enclosure from the incubation enclosure, making it possible to obtain the intial complex 300,

the support (M1) and / or the other support (M2) may be in divided form, for example of particles, which may contain or contain, if necessary, a magnetic material,

- the contacts according to steps (b) and (e), in a liquid medium, take place in two separate incubation chambers,

- before step (d) of dissociation, a fraction enriched in complex 300 is separated from the liquid medium obtained, after contacting,

- after or during step (b), various washes can be carried out, on the one hand to remove the second labeled ligand (L2, E) in excess, and on the other hand to remove this same reagent, weakly adsorbed , functionalized support (Mi, Li),

- By working in a liquid medium, and in particular with supports (Mi) and / or (M ₂₎ in the form of magnetic particles, it is possible to separate the conjugate 301 from the supernatant from the liquid medium.

As is well known to those skilled in the art in the field of immunoassays:

- By "target species" or "analyte" means any entity, in particular biological, that we want to determine, that is to say detect qualitatively and / or quantitatively; by way of example, it is an antibody or an antigen, or also a polynucleotide; - "ligand" means any entity capable of binding, for example specifically, by weak bonds, for example of hydrogen type, with a site, called ligation, belonging to the target species; it is for example an antibody or an antigen, or also a polynucleotide, partly complementary to a target polynucleotide; - By "support" is meant any substrate, in divided or undivided form, generally having an inert nature with respect to the analyte and / or a ligand, making it possible by functionalization to attach an editorial entity, for example a ligand;

- By "functionalization" means any chemical treatment of chemical, physicochemical, or biochemical, or even biological type, making it possible to attach the above-mentioned editorial entity to the support. To implement a determination method as defined above, a device in accordance with FIG. 1 is adapted, as shown in FIG. 14, as follows:

- It comprises an incubation enclosure 305, the outlet 306 of which communicates with the inlet duct 41 of the device according to the invention, and the operating cavity 12 comprises, in the form of filling in the manner of a chromatography column, particles 303 as defined above, that is to say the support (M ₂ ) functionalized with the third ligand (L ₃ ), - a means 307, for example of heating, of oriented dissociation is arranged in relation to the conduit entry 41, at the exit of the incubation enclosure 305, and this so as to allow the dissociation of the complex 300, previously defined, between the support (Mi) the first ligand (Li), and the target species (C), and the second labeled ligand (Mi, L ₂ ); this means 307 can be associated, where appropriate, with a means for concentrating complex "300,

a means 308 for retaining particles, for example of the magnetic type, is disposed downstream of the dissociation means 307, still in relation to the inlet conduit 41, for retaining the particles of the functionalized support 302, dissociated from the complex 300 .

In this way, the conjugate 301 can circulate towards the operating cavity 3, and bind in the latter with the particles of the functionalized support 303 (M ₂ , L ₃ )

Claims

1) Fluidic device (1) arranged from one or more components, for example from a support (12), comprising: - an operating cavity (3),

- at least two conduits (41, 42), for example inlet (41) and outlet (42) of a liquid of interest, communicating with the operating cavity (3), respectively via two organs (51, 52) without moving part, of the valve type, for controlling the operating cavity, - two trapping chambers (81, 82) of a gas, for example air, communicating only and respectively with the two conduits (41) and (42), by two connecting channels (91, 92) distinct respectively from the two said conduits,

- Heat exchange means with one and / or the other trapping chamber (81, 82), in order to control the pressure of the gas in one and / or the other trapping chamber.

2) Device according to claim 1, characterized in that each member (51, 52) without moving part is a capillary valve.

3) Device according to claim 1 or 2, characterized in that each capillary valve is arranged to generate an overpressure at the interface between the gas and the liquid of interest, said meniscus, opposing any movement of the liquid au- beyond the valve, against overpressure.

4) Device according to any one of claims 1 to 3, characterized in that each capillary valve (71, 72, 51, 52, 101, 102) comprises a seat whose section increases in the direction of the concavity of said meniscus, when the liquid of interest is wetting, or the section of which decreases in the direction of said concavity when said liquid of interest is not wetting.

5) Device according to any one of claims 1 to 4, characterized in that it comprises two isolation means (201, 202), disposed respectively on the two conduits (41, 42), each arranged to take two positions , namely an open position establishing a communication of a said conduit with the outside, and a closed position isolating said conduit from the outside.

6) Device according to any one of claims 1 to 5, characterized in that it comprises two expansion chambers (61, 62), each arranged between said operating cavity (3) and each conduit (41, 42), each chamber communicating on one side with said conduit by a first capillary valve (71, 72) without moving part, opposing any liquid passage towards said chamber, and on the other side with said cavity by a second capillary valve ( 51, 52), opposing any liquid passage to said chamber.

7) Device according to claim 6, characterized in that the two connecting channels (91, 92) each connect a trapping chamber (81, 82) with an expansion chamber (61, 62).

8) Device according to claim 6 or 7, characterized in that each connecting channel (91, 92) communicates with the corresponding expansion chamber (61, 62), by a capillary valve (101, 102) without moving part, opposing any liquid passage to said trapping chamber (81) or (82).

9) Device according to any one of claims 6 to 8, characterized in that the two expansion chambers (61, 62) are substantially identical, in particular in volume.

10) Device according to any one of claims 1 to 9, characterized in that the two trapping chambers (81, 82) are substantially identical, in particular in volume.

11) Device according to claim 1, characterized in that it comprises an incubation enclosure (305) whose outlet (306) communicates with the inlet conduit (41) and the operating cavity (3) comprises, in the form of particles (303), a support (M ₂ ) functionalized with a ligand (L ₃ )

12) Device according to claim 1, characterized in that a means (307) of oriented dissociation, for example heating, is arranged in relation to the inlet duct (41).

13) Device according to claim 12, characterized in that a retention means (308) of particles, for example magnetic, is arranged in relation to the inlet duct (41), downstream relative to the means (307) oriented dissociation.

14. Use of the fluidic device (1) according to any one of claims 6 to 9, for isolating or confining all or part of a liquid of interest at the level of the operating cavity (3), characterized in that: a ) beforehand, by circulation of the liquid of interest, from an inlet conduit (41) to the other outlet conduit (42), the operating cavity (3) and the expansion chambers (61) are filled , 62), by retaining a residual gas, for example air, in the two trapping chambers (81, 82), b) after circulation of the liquid of interest, the residual gas is carried in the two trapping chambers , at a so-called isolation temperature to bring the pressure in said trapping chambers to a value called equilibrium pressure, sufficient to evacuate all or part of the liquid of interest from the two expansion chambers (61, 62) by at at least one of the two conduits (41, 42), and fill all or part of said chambers with two gas bubbles residual, isolating the operating cavity from any leakage of the liquid of interest and / or any diffusion of the particles contained in said liquid of interest towards said conduits (41, 42).

15) Use of the fluidic device (1) according to any one of claims 6 to 9, to isolate or confine and stir all or part of a liquid of interest at the level of the operating cavity (3), characterized in that : a) beforehand, by circulation of the liquid of interest, from an inlet conduit (41) to the other outlet conduit (42), the operating cavity (3) and the expansion chambers are filled (61, 62), retaining a residual gas, for example air, in the two trapping chambers (81, 82), b) after circulation of the liquid of interest, the residual gas is carried in the two chambers trapping, at a so-called isolation temperature, to bring the pressure in said trapping chambers to a so-called value equilibrium pressure, sufficient to evacuate all or part of the liquid of interest from the two expansion chambers (61, 62) by at least one of the two conduits (41, 42), and fill all or part of said chambers with two bubbles residual gas, isolating the operating cavity from any leakage of the liquid of interest and / or any diffusion of the particles contained in said liquid of interest towards said conduits (41, 42), c) the temperature of the residual gas present in at least one of the trapping chambers (81, 82), in order to modify its pressure and move the liquid of interest towards one of the expansion chambers (61, 62), without breaking the isolation of the operating cavity (3), d) the temperature of the residual gas present in at least one of the trapping chambers (81, 82) is again modified, in order to modify its pressure again and move the liquid of interest towards the other of the expansion chambers (61, 62), without breaking the isolation of the operating cavity (3).

16) Use according to claim 15, characterized in that the pressure obtained in step (d) is the equilibrium pressure.

17) Use according to claim 15, characterized in that steps (c) and (d) are repeated.

18) Use of the fluidic device (1) according to any one of claims 6 to 9, for agitating the content of the operating cavity (3), characterized in that: a) beforehand, by circulation of the liquid of interest, to from an inlet duct (41) to the other outlet duct (42), the operating cavity (3) and the two expansion chambers (61, 62) are filled, retaining a residual gas, by example of air, in the two trapping chambers (81, 82), at a predetermined temperature, called the filling temperature, b) then, from the filling temperature, the residual gas is heated to a so-called reference temperature in one (81) and the other (82) of the trapping chambers, but at a higher value called high in one (82) compared to the value called low in the other (81) trapping chamber , whereby we form in the expansion chamber (61) associated with said other trapping chamber (81), a portion (20) disc rete liquid of interest, compressing the residual gas therein, and form in the expansion chamber (62) associated with the trapping chamber (82) a residual gas bubble, c) the temperature of the residual gas in the other (81) of the trapping chambers is again increased, whereby the displacement is the same proportion (20) of the liquid of interest from the operating cavity (3) to the expansion chamber (62) associated with said trapping chamber (82), compressing the residual gas therein, d) the temperature of the residual gas in the other (81) of the trapping chambers is brought back to the so-called reference temperature, at its low value, by means of which the same portion (20) is displaced towards the associated expansion chamber (61) to said trapping chamber (81),

19) Use according to claim 18, characterized in that, during step (b), the residual gas is heated in one (81) and the other (82) of the trapping chambers, simultaneously or successively.

20) Use according to claim 18, characterized in that the operations (c) and (d) are repeated an integer number of times, to generate oscillations of the discrete portion (20) through the operating cavity (3). 21) Use according to claim 14, of a device according to claim 10, for implementing an ELISA or ELOSA type method, for determining a target species, or analyte (C), comprising two sites ( Ci, C ₂ ) of ligation respectively with a first ligand (Li _. ) And with a second ligand (L ₂ ), linked directly or indirectly to a marker E, said method comprising the following steps: a) a support is available (Mi) functionalized with the first ligand (Li), placed in an incubation chamber (Mi, Li), b) in a liquid medium, in the incubation chamber, the support is brought into contact, simultaneously or successively functionalized (Mi, Li), the target species (C) or analyte, and the second labeled ligand (L ₂ , E); to obtain a complex (300) first ligand support / target species / second labeled ligand, c) there is another functionalized support (M ₂ ) (303) with a third ligand (L ₃ ) capable of binding to target species (C), d) the complex (300) is dissociated in an oriented manner, in order to separate a conjugate (301) associating the target species / second labeled ligand, from the functionalized support (302) (Mi, Li), e) in a liquid medium, in contact with the other functionalized support (303) (M ₂ , L ₃ ), with the conjugate (301), to obtain another complex (304) another support / third ligand / target species / second labeled ligand; f) the marker (E) of the other complex (304) is detected qualitatively and / or quantitatively.