Sequential pumping by means of an actuator

Abstract

The invention relates to a centrifugal microfluidic cartridge module for operation in a centrifugal microfluidic device and / or centrifuge, having the following features: a first chamber (1) which is designed to receive a liquid and / or gas and to apply, by means of pressure generation means (14), an underpressure or overpressure relative to an initial pressure to the liquid and / or gas; a second chamber (2); a third chamber (3); and a node (ZP) which is connected via a fluidic network to the first, second and third chambers (1, 2, 3), wherein the fluidic network has a first partial channel (TK1), which connects the node (ZP) to the first chamber (1), a second partial channel (TK2), which connects the node (ZP) to the second chamber (2), and a third partial channel (TK3), which connects the node to the third chamber (3); wherein a second channel (K2) connects the second and the third chambers (2, 3) to one another and opens into a radially outer region or at the radially outer end of the second chamber (2) and has at least one radially inwardly directed portion; wherein the third partial channel (TK3) has a portion which extends further inwards, seen radially, than the second partial channel (TK2).

Description

[0001] Sequential pumping using an actuator

[0002] Description

[0003] Technical area

[0004] Embodiments of the present invention relate to a centrifugal microfluidic cartridge module and a corresponding method for operating the centrifugal microfluidic cartridge module. Preferred embodiments relate to sequential pumping by means of an actuator.

[0005] background

[0006] Microfluidics, and its subtype of centrifugal microfluidics discussed here, in which the microfluidics are rotated to actuate the fluid, deals with the handling of fluids in the fl - ml range. Such systems are often disposable polymer cartridges, as these offer great potential for cost-effective mass production. This allows standard laboratory processes such as pipetting, centrifuging, mixing, or aliquoting to be implemented in a centrifugal microfluidic cartridge, thus automating entire laboratory processes. For this purpose, the cartridges contain channels for fluid guidance and chambers for collecting fluids. Centrifugal microfluidics finds applications in laboratory analytics and diagnostics, among other areas.

[0007] It should be noted here that microfluidics focuses on the processing of fluids, and these fluids can be in both a liquid and a gaseous state. Therefore, it goes without saying that microfluidic devices are also suitable for gases.

[0008] For many possible applications, such as DNA extraction and purification, liquid reagents such as lysis, binding, washing, and elution buffers are first pumped from a pre-storage chamber into a reaction chamber and, after reaction, into one or more target chambers. A separate actuator is usually required for each of these pumping processes, especially if the reaction chamber is vented. Temperature or frequency changes are often used as actuation principles in centrifugal microfluidics, among other possibilities, to achieve the necessary

[0009] I I240302PCT-2024063148. DOCX To generate pressure in compression chambers and thus enable fluid transport (for example, by enclosing a gas volume in a compression chamber using fluid at a comparatively high rotation frequency and compressing it using hydrostatic pressure. When switching to a comparatively lower rotation frequency, the gas expands and can be used as a pumping mechanism). A disadvantage of current solutions is the space required by a large number of compression chambers to implement sequential pumping steps. Therefore, there is a need for an improved approach.

[0010] State of the art

[0011] The following section discusses the state of the art and highlights further problems. In particular, identifying problems already represents part of the solution and is therefore considered an integral part of the invention.

[0012] A selection of common methods for liquid transport in centrifugal microfluidic cartridges is described below.

[0013] In the publication by THG Thio et al. titled “Push-pull microfluidics on a multi-level 3D CD” Lab Chip, 2013, 13, pp. 3199-3209, a microfluidic structure is described (Fig. 2) featuring a compression chamber that is first heated. The positive pressure is used to switch fluid from chamber B to the radially outer chamber A via a siphon. The compression chamber is then cooled, and the fluid is then drawn back to the outlet chamber B via the same siphon using negative pressure.

[0014] In the publication by P. Jülg et al. titled "Automated serial dilutions for high-dynamic-range assays enabled by fill-level-coupled valving in centrifugal microfluidics" Lab Chip, 2019, 19, 2205-2219, a microfluidic structure is described that enables switching / pumping into another chamber depending on the fill level in one chamber. Similar to the proposed patent, the transfer is enabled by a channel (Fig. 3, top left: fill-level-coupled siphon) being partially filled with liquid at a specific time, thus making it inaccessible to gas. As a result, the liquid is pumped further through another channel (transfer siphon).

[0015] Final subs cc II240302PCT-2024063148.DOCX In L. Malic et al.'s study entitled "Automated sample-to-answer centrifugal microfluidic system for rapid molecular diagnostics of SARS-CoV-2" Lab Chip, 2022, 22, 3157-3171, a centrifugal microfluidic platform connected to an external compressed air system is used (Fig. 4). The chambers and channels of the microfluidic chip can be pressurized or vacuumized via several pressure ports. In the present example, port 1 is first operated at positive pressure to mix a liquid, then at negative pressure to transfer the liquid into a chamber via a siphon.

[0016] The patent DE102016207845A1 & family describes a fluidic structure that makes it possible to prime a siphon by temporarily building up a pressure difference in a microfluidic cartridge and thus trigger a valve function (Fig. 5).

[0017] Implementation examples

[0018] The object of the present invention is to create an improved concept for the actuators between at least three chambers.

[0019] The object is achieved by the subject matter of the independent patent claims. Embodiments of the present invention provide a centrifugal microfluidic cartridge module for operation in a centrifugal microfluidic device and / or a centrifuge. The cartridge module comprises a first chamber, a second chamber, and a third chamber. The first chamber is configured to receive a fluid and / or a gas and, by means of pressure generation, to subject the fluid and / or gas to a negative pressure and / or positive pressure relative to an initial pressure. Furthermore, the cartridge module comprises a node connected to the first, second, and third chambers via a fluidic network.The fluidic network has a first partial channel (TK1) which connects the node point to the first chamber, a second partial channel (TK2) which connects the node point to a second chamber, and a third partial channel (TK3) which connects the node point to the third chamber. A second channel (K2) connects the second and third chambers to one another, opening into a radially outer region or at the radially outer end of the second chamber and having at least one radially inwardly directed section. The third partial channel (TK3) has a section which, viewed radially, runs further inward than the second partial channel (TK2).

[0020] Final subs cc II240302PCT-2024063148.DOCX Embodiments of the present invention are based on the finding that a fluid can be pumped back and forth between three chambers or from a first to a second and from a second to a third chamber if these three chambers are connected to one another by a fluidic network, namely by the fluidic network directly connecting all chambers to a central node, with the second chamber (reaction chamber) and the third chamber (target chamber) being connected by a further connection, e.g. a direct connection. By cleverly arranging this connection at the second chamber and the spatial radial arrangement or the corresponding design of the fluidic resistances of the sub-channels and channels, precisely this pumping from the first chamber to the second chamber to the third chamber can be achieved.The individual pumping activities are controlled by a negative or positive pressure generated in the first chamber compared to an initial pressure. Positive pressure causes the fluid to be transported from the first chamber to the second chamber, while negative pressure causes the fluid to be transported from the second to the third chamber. The advantage and differentiation from the state of the art is the sequential pumping of a fluid into different chambers using a single chamber to generate pressure (negative / positive pressure). In particular, the possibility of pumping the fluid from a vented chamber into one or more target chambers in a final step cannot be realized with the state of the art without additional microfluidic acutation structures.The procedure of designing the intermediate structure in such a way that it can be used for liquid transport during the first pumping process, but has a very high fluidic resistance during the second pumping process and thus cannot be used for pressure reduction, is not apparent to the person skilled in the art.

[0021] According to exemplary embodiments, the second sub-channel (TK2) has a higher fluidic resistance than the second channel (K2). This is relative to the (same) fluid or gas. Possible implementations of this variant include varying the cross-section and / or length.

[0022] According to the exemplary embodiments, the second channel (K2) and the second sub-channel (TK2) extend radially further outwards than the third sub-channel (TK3). When the liquid is transported from chamber 1 to chamber 2 by means of an overpressure, the rotation and the resulting centrifugal forces in the second

[0023] Final subs cc II240302PCT-2024063148.DOCX and third sub-channel (TK3) transports the fluid via the second sub-channel (TK2) to the second chamber starting from the node, wherein the overpressure causes the fluid to be transported from the first chamber to the node.

[0024] According to embodiments, when a negative pressure is applied, the fluid is transported from the second chamber towards the first chamber, but via the path that has the lower fluidic resistance. Starting with a fluid in the second chamber, the second channel (K2) has the lower fluidic resistance than the second sub-channel (TK2), so that the fluid is transported from the second to the third chamber. It is therefore advantageously possible to effect a transport of the fluid from the second to the third chamber using a negative pressure, while according to embodiments the fluid is transported from the first to the second chamber using an overpressure (see above). According to an alternative variant, a geometric arrangement of the vertices of the second channel (K2) and the second sub-channel (TK2) can be used instead of or in addition to the fluidic resistance.According to embodiments, the cartridge module has an apex in the second channel (K2) that is located radially further outward than an apex of the second sub-channel (TK2), so that when filling the second channel (K2), a smaller maximum hydrostatic counterforce is exerted on the fluid and / or the gas than when filling the second sub-channel (TK2). In this way, the pumping process from the second chamber to the third chamber can advantageously be realized.

[0025] According to embodiments, the means for generating pressure comprise, for example, means for controlling the temperature of the fluid and / or the gas. These are, in particular, heating and / or cooling means designed to generate the overpressure by increasing the temperature and the negative pressure by reducing the temperature in the first chamber. These heating and / or cooling means can be applied either locally to specific parts of the microfluidic structure (e.g., via one or more Peltier elements located near these parts of the microfluidic structure) or to the entire cartridge (e.g., via heating or cooling the space in which the cartridge is located during fluid actuation).

[0026] According to embodiments, a container can be inserted or can be inserted into the first chamber, wherein the container in the first chamber is opened due to an acceleration and / or a combination of hydrostatic force resulting from an acceleration and a temperature increase. This means that the first chamber

[0027] Final subs cc II240302PCT-2024063148.DOCX is designed to open a container in the first chamber due to an acceleration and / or a combination of hydrostatic force resulting from an acceleration and a temperature increase. The acceleration and / or temperature increase is controlled, for example, by a controller.

[0028] According to embodiments, the cartridge module has a controller and is connected to a controller that is designed to effect a pumping process of a fluid from the first chamber to the second chamber by increasing the temperature in the first chamber and optionally additionally reducing a rotation frequency of the cartridge module. Alternatively, the controller is designed to induce a pumping process of the fluid from the first chamber into the second chamber by increasing the temperature and optionally additionally reducing the rotation frequency of the cartridge module, wherein the pumping process is characterized in that the overpressure in the first chamber is sufficiently large to convey the liquid over the apex of the inverse siphon formed by TK1 and TK2. The overpressure is smaller than the pressure that would be necessary to convey the liquid over the apex of the inverse siphon formed by TK1 and TK3.

[0029] According to further embodiments, the controller is designed to reduce the temperature of the fluid in the first chamber. This can generate a negative pressure in the first chamber, which acts on the fluid in the second chamber via the first sub-channel (TK1) and the second sub-channel (TK2) or via the first sub-channel (TK1), the third sub-channel (TK3), and the second channel (K2). According to embodiments, this negative pressure then causes the fluid to be transported from the second chamber to the third chamber, as already explained above.

[0030] According to embodiments, the third chamber has a connection to the second channel, which is arranged radially further inward than the maximum possible filling level of the third chamber.

[0031] According to a further embodiment, the junction point is formed by a further chamber. This advantageously makes it possible to prevent the third sub-channel (TK3) from being filled with liquid during the first pumping process. For this purpose, for example, the opening of the third sub-channel (TK3) into the chamber can be designed such that it is located at the upper edge of the chamber and thus above the maximum possible fill level. According to a further embodiment,

[0032] Final subs cc II240302PCT-2024063148.DOCX It is possible for additional chambers to be provided between the junction point and the second chamber, e.g., in the form of a cascade. According to embodiments, the second sub-channel (TK2) is designed to retain a portion of the fluid during transport of the fluid from the first chamber to the second chamber. This can be achieved, among other things, by appropriately arranging the channels at additional chambers so that they do not empty completely.

[0033] According to embodiments, the cartridge module is designed to be arranged in a centrifuge and / or to be centrifuged by means of a centrifuge. This means that, according to embodiments, a centrifuge with a corresponding cartridge module is created. According to one embodiment, the first chamber, the second chamber, and the third chamber are rotatable about a rotation axis or common rotation axis.

[0034] According to one embodiment, a direct connection can be provided between the first chamber and the third chamber. Such a structure makes it possible, for example, to dilute the liquid with the starting liquid after it has been directed into the third chamber.

[0035] According to one embodiment, one or more additional third chambers are provided parallel to the third chamber, which are arranged between the third sub-channel (TK3) and the second channel. This allows the fluid to be split into several chambers.

[0036] At this point it should be noted that the liquid does not necessarily have to be present directly in the first chamber, but can also be provided as a kind of tubular bag or, in particular, a stick pack.

[0037] Another embodiment provides a method for operating a cartridge module comprising the following steps:

[0038] Applying an overpressure to convey a fluid and / or gas from the first chamber to the second chamber; and

[0039] Final subs cc II240302PCT-2024063148.DOCX Applying a negative pressure to transport a fluid and / or gas from the second chamber to the third chamber.

[0040] Further formations are defined in the subclaims.

[0041] Short character description

[0042] The following examples are explained using the attached figures. They show:

[0043] Fig. 1 is a schematic representation of a microfluidic layout according to a basic embodiment of the invention;

[0044] Fig. 2 is a schematic diagram illustrating the principle of the publication by Thio et al.;

[0045] Fig. 3 a schematic representation of the switching principle of the publication by Jülg et al.;

[0046] Fig. 4 an illustration of the layout and fluidic operation 1 and 2 in L. Malic et al.;

[0047] Fig. 5 a layout of DE 10201620785 A1 ;

[0048] Fig. 6 is a schematic representation of a microfluidic structure for discussing its mode of operation according to embodiments;

[0049] Fig. 7a-e schematic representation to illustrate an embodiment for the sequential transport of the liquid according to embodiments;

[0050] Fig. 8 is a representation of an embodiment for the sequential transport of the liquid with additional dilution of the liquid in the target chamber according to embodiments; and

[0051] Final subs cc II240302PCT-2024063148.DOCX Fig. 9 is a schematic representation of an embodiment in which the aliquoting of the liquid is possible with a second pumping step.

[0052] Detailed description of the implementation examples

[0053] Before exemplary embodiments of the present invention are explained below with reference to the accompanying drawings, it should be noted that elements and structures with the same function are provided with the same reference numerals, so that the description of them is applicable to one another or interchangeable.

[0054] Before going into further details of the embodiments, the physical principles behind the embodiments are explained.

[0055] Fluidic resistance: The fluidic resistance of a channel can be defined as the quotient of the pressure drop Ap in a channel and the flow rate q:

[0056] R = Ap / q.

[0057] Depending on the channel cross-sectional geometry, the pressure drop can be derived analytically or approximated. The fluidic resistance of a channel can be determined, for example, by measuring the pressure drop and the flow rate. Unless otherwise stated, it is assumed that fluidic resistances are being compared for identical fluids at identical temperatures.

[0058] Hydrostatic pressure by centrifugation: The hydrostatic pressure on a liquid column in a channel in the centrifugal gravitational field can be calculated using the following formula:

[0059] Where p is the density of the liquid, w is the angular velocity with which the channel rotates around the center of rotation, r a for the outer radius of the liquid column and M for the inner radius of the liquid column. This formula is also valid if the liquid column is not confined to a single channel, but, for example, partially fills a chamber and an adjacent channel.

[0060] Final subs cc II240302PCT-2024063148.DOCX Total pressure: The pressure generated in a chamber consists of two components: a vapor pressure generated by the ideal gas law and a vapor pressure resulting from the evaporation of liquids. The total pressure of the system p GeSamt can be described by the following formula:

[0061] Here, p describes Gas The pressure generated by the ideal gas law and the pressure generated by the evaporated liquid. The formula for the vapor pressure fraction is usually empirically determined correlations that are determined individually for each liquid and depend on the temperature. describes the relative humidity of the gas. At 100%, the gas is completely saturated with a liquid. In microfluidic structures, the gas is usually completely saturated.

[0062] Examples of fluidic structures, e.g., microfluidic structures, are fluid channels and fluid chambers. Fluidic structures can define an overflow structure that can be used to measure fluid volumes. The basic principle is that the fluid first fills a chamber with a defined volume, and the remaining fluid is then transported to another chamber. Compression chambers are chambers that either have no venting or only one vent with high fluidic resistance. This allows a pressure p to be maintained in these chambers. Gesa mt, which is described in the formula defined above.

[0063] As will be apparent to those skilled in the art, the term "liquid" as used herein includes, in particular, liquids containing solid components, such as suspensions, biological samples, and reagents. In particular, this includes buffer solutions such as lysis buffers, binding buffers, wash buffers, and elution buffers, as used in laboratory analysis and mobile diagnostics.

[0064] An inverted siphon channel is understood here as a microfluidic channel or section of a microfluidic channel in a fluidic module (a centrifugal microfluidic cartridge) in which the inlet and outlet of the channel are separated by a greater distance

[0065] Final subs cc II240302PCT-2024063148.DOCX from the center of rotation than an intermediate region of the channel. A siphon apex is the region of an inverse siphon channel in a fluidic module with the minimum distance from the center of rotation.

[0066] When the term radial is used herein, it means radial with respect to the center of rotation around which the fluidic module or the rotating body is rotatable. In the centrifugal field, a radial direction away from the center of rotation is radially decreasing, and a radial direction towards the center of rotation is radially increasing. A fluid channel whose beginning is closer to the center of rotation than its end is thus radially decreasing, while a fluid channel whose beginning is further from the center of rotation than its end is radially increasing. A channel with a radially increasing section therefore has directional components that increase radially or run radially inwards. It is clear that such a channel does not have to run exactly along a radial line, but can run at an angle to the radial line or be curved.

[0067] Unless otherwise stated herein, room temperature (20°C) shall be assumed with regard to temperature-dependent quantities.

[0068] Fig. 1 shows a centrifugal microfluidic cartridge module for operation in a centrifugal microfluidic device or a centrifuge. The cartridge module 10 has three chambers 1, 2 and 3, whereby the first chamber 1 can be referred to as the output chamber, the second chamber 2 as the reaction chamber and the third chamber 3 as the target chamber. Chamber 2 is vented as shown, whereby this venting can either lead directly to the environment or represent a connection to the rest of the fluidic network of the cartridge module. The three chambers are connected to one another via a fluidic network, whereby the fluidic network has a central node ZP. The central node ZP is located between the three chambers 1, 2 and 3 and connects them to one another. For this purpose, the fluidic network has a first sub-channel (TK1), a second sub-channel (TK2) and a third sub-channel (TK3).The first sub-channel (TK1) connects the node point (ZP) with the first chamber. The second sub-channel (TK2) connects the node point (ZP) with the second chamber. The third sub-channel (TK3) connects the node point (ZP) with the third chamber. In addition, the second chamber is directly connected to the third chamber via a further channel, which is referred to below as the second channel (K2). All three chambers (1, 2 and 3) as well as the fluidic network consisting of TK1 + TK2 + TK3 + ZP + K2 are mechanically coupled to one another, so that they can be used together, e.g. in a centrifuge (not shown), around the rotation axis 12.

[0069] Final subs cc II240302PCT-2024063148.DOCX radius R. Depending on the element, chamber 1, chamber 2, chamber 3 or central node ZP, the radii R to the axis of rotation 12 are different. As a result, the fluids in the individual chambers (1, 2, 3) or channels (TK1, TK2, TK3, K2) experience different centrifugal forces. As a result of these centrifugal forces during rotation and the change in pressure in chamber 1, the fluid is moved in the fluidic network or from chamber 1 to chamber 2 to chamber 3. Actuators are used to control the individual pumping processes, e.g. from chamber 1 to chamber 2 or from chamber 2 to chamber 3. According to embodiments, this actuator comprises means for generating pressure in the chamber 1. These means are provided with the reference numeral 14 and can be implemented by temperature control means according to embodiments.By means of a temperature variation, an overpressure and / or a negative pressure can be generated in the chamber 1 relative to an initial pressure, e.g. an initial pressure in the system comprising the components 1, 2, 3, TK1, TK2, TK3 and K2. By heating the fluid in the chamber 1, an overpressure is generated therein. After the first pumping process, this overpressure generally dissipates via the fluidic network. By reducing the temperature, a negative pressure, relative to the initial pressure before the temperature reduction, is then generated in the chamber 1 in a second step. The means for generating pressure 14 therefore comprise, according to exemplary embodiments, means for generating heat, such as a heater, and means for cooling the fluid in the chamber 1.

[0070] Now that the structure has been explained, the functionality will be discussed below.

[0071] The structure of the centrifugal microfluidic cartridge 10 enables a pumping process from a chamber 1 acting as a compression chamber into a second, e.g., ventilated chamber 2 in a pumping step 1, as well as a further pumping process (pumping step 2) into a third chamber 3. This second pumping step follows, for example, the first pumping step and can be referred to as a separate step. Control or separation of pumping step 1 from pumping step 2 is achieved by the pressure generation means 14.

[0072] Chamber 1 acts, in addition to the centrifugal force, as an actuator for liquid transfer in the centrifugal microfluidic structure by heating or cooling the liquid / gas in chamber 1, either overpressure or negative pressure is applied to at least parts of the

[0073] Final subs cc II240302PCT-2024063148.DOCX remaining centrifugal microfluidic structure. The liquid is transported from chamber 1 to chamber 2 by overpressure, and from chamber 2 to chamber 3 by negative pressure. The core of the invention is that in the intermediate structure (TK2) after pumping step 1, a relatively high fluidic resistance exists compared to channel K2, either inherently due to the design (small structures with high fluidic resistance) and / or due to residual liquid that remains in the intermediate structure after pumping step 1. Accordingly, for pumping step 2, the negative pressure can be applied to the liquid in chamber 2 via channels TK1 and TK3, chamber 3 and channel K2, and this liquid can be transferred to chamber 3 via channel K2. Due to the different fluidic resistances of the intermediate structure and channel K2, the liquid is preferentially pumped through channel K2 into chamber 3.

[0074] With regard to the exemplary embodiment from Fig. 1, it should be noted that a distinction can be made between two different implementations of the fluidic network, although mixed forms can also be used. Both implementations have in common that the second channel (K2) connects the second chamber and third chamber to one another, specifically in a radially outer region or at the radially outer end of chamber 2 (mouth of chamber 2). Furthermore, the second channel (K2) has at least one section directed radially inward. Radially inward means towards the axis of rotation 12 (closer to the axis of rotation). The third sub-channel (TK3) also has a section that runs further inward, viewed radially, than the second sub-channel (TK2). Based on this basic structure, according to a first variant, the second sub-channel (TK2) can have a higher fluidic resistance than the second channel (K2) with respect to the same liquid or gas.According to a second variant, a peak in the second channel (K2) can be located further radially outward than a peak in the second sub-channel (TK2), so that the hydrostatic pressure that must be overcome due to the rotation during the second pumping process is lower in the second channel (K2) than in the second sub-channel (TK2). The peak in the second channel (K2) is labeled SK2, and the peak in the second sub-channel (TK2) is labeled STK2. The radial difference between the two peaks is labeled Ar. If the negative pressure now fulfills the condition that it is lower than the hydrostatic pressure acting in the second sub-channel (TK2) when STK2 is reached, and greater than the hydrostatic pressure in the second channel (K2) when SK2 is reached, the fluid is transferred exclusively to the third chamber, since the siphon consisting of TK1, ZP and TK2 cannot be primed.Both variants allow the creation of a negative pressure in the first chamber using the element.

[0075] Final subs cc II240302PCT-2024063148.DOCX 14 to control pumping process 2 so that a large part of the liquid is transferred from chamber 2 to chamber 3.

[0076] The structure explained above is described again below in other words and optional aspects are discussed. Chamber 3 can be arranged in any direction relative to chamber 2 (ie, for example, in particular radially inwards). Chamber 2 and chamber 3 are connected via a channel (K2). Chamber 3 is also connected to a node (ZP) via a channel TK3. The node can be designed as a T-piece (meeting point of three channels) or as a chamber. From this node, an intermediate structure (TK2), which in this case consists of at least one channel and no or at least one intermediate chamber, leads to chamber 2. Chamber 1 is also connected to the node via channel TK1.

[0077] In the device presented here, the actuation principle is as follows: In centrifugal microfluidics, temperature or frequency changes are often used as actuation principles, among other options, to generate the necessary pressure in compression chambers and thus enable fluid transport. A disadvantage of current solutions is the space required by the large number of compression chambers required to implement sequential pumping steps.

[0078] The process behind this can be described as follows: The liquid in chamber 1 can, for example, be stored in a tubular bag (stick pack). Stick packs can be opened during processing by centrifugal force or a combination of centrifugal force and temperature, which leads to the release of the liquid. By increasing the temperature in chamber 1, an overpressure is built up there. The frequency is then reduced to such an extent that the overpressure in chamber 1 is greater than the maximum possible centrifugally induced hydrostatic pressure in sub-channel TK1 . The inner radius is the position of the node (corresponds to the apex of the inverse siphon formed by the sub-channels TK1 and TK2) and the outer radius corresponds to the radial position of the liquid meniscus in chamber 1 .

[0079] However, the overpressure in chamber 1 is lower than the maximum possible hydrostatic pressure in the sub-channels TK1 and TK3 . By selecting the overpressure in chamber 1 and the rotation frequency of the cartridge module, it is ensured that the

[0080] Final subs cc II240302PCT-2024063148.DOCX Fluid is pumped from chamber 1 exclusively via channel TK2 into chamber 2. Towards the end of the pumping process, the pressure in chamber 1 equalizes via TK1, TK2 and TK3 to the pressure level in the remaining fluidic cartridge, whereby the temperature in chamber 1 is still elevated.

[0081] No liquid is pumped through channel TK3; it only serves for gas exchange between chamber 1 and chamber 3 once the liquid has been pumped out of chamber 1 and channels TK1 and TK3 are filled with gas. To implement the second pumping process, chamber 1 is cooled, creating a negative pressure compared to the remaining pressure level in the microfluidic cartridge in this chamber. This pressure acts on the liquid in chamber 2 via channels TK1 and TK2 on the one hand, and via channels TK1, TK3, and K2 on the other. The fluidic resistance of channel TK2 is so high compared to channel K2 that the liquid does not reach the branching point of TK1, TK2, and TK3 (ZP) during the pumping process, and is therefore pumped almost entirely via channel K2 into chamber 3.

[0082] What all embodiments have in common is that they describe a microfluidic structure with which a liquid can be sequentially pumped into several consecutively connected, e.g., ventilated chambers using only a single compression chamber. Possible applications include DNA extraction and purification, in which liquid reagents, such as lysis, binding, washing, and elution buffers, are first pumped from a pre-storage chamber 1 into a reaction chamber 2 and, after the reaction, further pumped into a target chamber 3.

[0083] According to a further embodiment, the structure explained above can be expanded to include additional chambers. In the variant shown in Fig. 7a-e, in addition to the three chambers 1, 2, 3 (output chamber, reaction chamber and target chamber), there is a further chamber 5, which is arranged between the central node and the chamber 2. In this embodiment, the central node is also formed by a further chamber 4. The two additional features, namely the use of a chamber 4 as a node and the provision of a chamber between the node and the reaction chamber, can be used together, but also individually. The channel section between the chamber 4 and the chamber 5 is designated here by the reference numeral

[0084] Final subs cc II240302PCT-2024063148.DOCX K3. According to optimal embodiments, K3 can have a (high) fluidic resistance, e.g., a higher fluidic resistance than the channel K2 between chambers 2 and 3.

[0085] Figs. 7a-c depict the pumping process from the outlet chamber 1 into the reaction chamber 2, assuming that the outlet chamber 1 is heated in the sequences depicted in Figs. 7a-c. Figs. 7d and 7e illustrate the second pumping process, in which the outlet chamber 1 is cooled. Now that the structure and illustration of the exemplary embodiment in Figs. 7a-d have been explained, the mode of operation will be discussed. It should be noted that the rotation frequency f2 is greater than the rotation frequencies f1 and f3. The additional structures added, in particular chamber 5 with the upstream channel K3, increase robustness during operation and enable a lighter design. The implementation of the node as a chamber also contributes to this.

[0086] In addition, a chamber 5 was introduced into the intermediate structure, which, due to its geometric shape as an overflow chamber, retains a defined volume of liquid. This makes it possible to ensure that the channel K3 always remains filled with liquid after the initial flow of liquid, thus enabling an effective pumping process from chamber 2 to chamber 3. In this exemplary embodiment, the negative pressure generated in chamber 1 acts on the liquid in chamber 2 only via the fluidic path TK1, chamber 4, TK3, chamber 3 and K2. In the initial state, there is liquid in chamber 1 (Fig. 7a). By increasing the temperature (locally or globally), an overpressure p Ggenerated entirely in chamber 1. Above a certain temperature, the overpressure generated in chamber 1 is greater than the centrifugally induced hydrostatic pressure on the liquid in channel TK1. This pumps the liquid from chamber 1 into chamber 4 (Fig. 7b). As soon as the entire volume of liquid has been pumped into chamber 4, the overpressure is completely equalized via channels TK1, TK3 and K2 as well as the vented chamber 2. By increasing the rotation frequency, the liquid is then transferred first from chamber 4 through channel K3 into chamber 5 and part of the liquid is then transferred through TK2 into chamber 2 (Fig. 7c).

[0087] In this embodiment, a portion of the liquid remains in chamber 5, which is designed as an overflow structure, while the majority of the liquid is transferred directly via channel TK2 into the vented reaction chamber (chamber 2) (Fig. 7d). In chamber

[0088] Final subs cc II240302PCT-2024063148.DOCX 2 Any reaction can then take place. This could, for example, involve the elution of biomolecules from a solid phase.

[0089] By reducing the temperature, a negative pressure is then created in chamber 1. Since chambers 3 and 4 are connected to chamber 1 via channels TK3 and TK1, a negative pressure also exists in these chambers. When the rotation frequency of the cartridge is reduced, the centrifugal pressure on the liquid in channel K2 decreases, and the negative pressure in chamber 3 pumps the liquid into chamber 3. At the same time, the liquid remaining in chamber 5 is also pumped through channel K3 into chamber 4. Channel K3 usually has a higher fluidic resistance than channel K2 to ensure that the pumping process in chamber 3 is completed first, even when the volume in chamber 5 is low.

[0090] Essential for the functioning in this embodiment is that liquid remains in chamber 5 and channel K3 and thus no sudden pressure equalization can take place via channels K3 and TK2 when the temperature is lowered.

[0091] Further embodiments are conceivable. For example, as shown in Fig. 8, in parallel with pumping the liquid from chamber 1 into chamber 4, a portion of the liquid from chamber 1 can be pumped into the target chamber (chamber 3), with the ratio of the pumped volumes depending on the resistance ratio of the channels TK1 and K4. Such a microfluidic structure makes it possible, for example, to dilute the liquid with the starting liquid after the reaction in the target chamber. At this point, it should be noted that, according to embodiments, the partial channel TK1 can form a type of siphon that, viewed radially, is located further inward than chamber 1 or the liquid level of chamber 1 (the innermost liquid level of chamber 1 viewed radially). Alternatively, the central node can also be located further inward than chamber 1 or the innermost liquid level of chamber 1.Here in this embodiment, as already mentioned above, the central node is formed by chamber 4. The reason for this is that the rotational force alone does not transport the liquid towards the central node. Here, for example, chamber 4 forms the central node.

[0092] It can also be seen here that chamber 2, i.e. the reaction chamber, can be ventilated according to embodiments.

[0093] Final subs cc II240302PCT-2024063148.DOCX Even if it was assumed in the above embodiments that the means for generating pressure can be provided by means for temperature control, such as for heating or cooling, according to further embodiments, a different principle for generating pressure, for example a chemical reaction or mechanical volume reduction, can also be used.

[0094] Another embodiment is shown in Fig. 9. This makes it possible to add additional chambers next to chamber 3. These chambers are also connected to channel TK3. Channel K2 branches off from chamber 2 and splits into channels K2.1, K2.2, ..., K2.N. This structure enables aliquoting of the fluid in the second pumping step. The aliquotted volumes depend on the fluid resistances of channels K2.1, K2.2, ..., K2.N.

[0095] Alternatives

[0096] Further embodiments are outlined below with reference to the above figures.

[0097] A further embodiment provides a fluidic module that is rotatable about a center of rotation. The fluidic module comprises the following features: a) a chamber 1 that is not vented b) with at least one outlet channel (TK1) that is attached radially to the outside of the chamber and opens into a node c) an intermediate structure leading from the node to a chamber 2 d) a channel leading from the node to a chamber 3 e) chamber 1 being partially filled with liquid, partially with a compressible medium f) a chamber 2 g) chamber 2 being fluidically connected to chamber 1 via an intermediate structure and to a chamber 3 via channel K2 h) the intermediate structure having a higher fluidic resistance for the flow of the same medium than channel K2 i) chamber 2 can have further connections to a fluidic network

[0098] Final subs cc II240302PCT-2024063148.DOCX According to embodiments, the chamber 2 can be vented via a channel.

[0099] According to further embodiments, the junction point can be formed as a T-piece (meeting of three channels or sub-channels).

[0100] According to further embodiments, the node point can be designed as a chamber.

[0101] According to further embodiments, the partial channel TK3 can be located radially inward between the central node and the third chamber, ie lead into the chamber at the node in such a way that the opening of the channel into the chamber is always above the maximum possible filling level of the chamber.

[0102] According to embodiments, the means for generating pressure are designed to generate the negative pressure and / or the positive pressure independently of the rotation, or at least to vary it independently of the rotation. For example, the positive pressure or the negative pressure can be generated or regulated by additional temperature or cold input.

[0103] According to embodiments, the sub-channel TK1 is connected to the central node ZP in such a way that the central node ZP is located radially further inward than the fluid level in the first chamber. This prevents a pumping process from being triggered by rotation alone or, in other words, ensures that the pumping process is actively controlled by the aforementioned pressure generation means.

[0104] According to further embodiments, at least one further chamber may exist in the intermediate structure, which is designed such that a part of the liquid flowing from chamber 1 into this chamber always remains in the connecting channel between these two chambers.

[0105] According to a further embodiment, chamber 1 can have a further outlet channel connecting this chamber to the third chamber. This channel is positioned radially outwardly of chamber 1 and radially inwardly of chamber 3.

[0106] According to a further embodiment, the temperature of the liquid / gas, e.g. in chamber 1, is adjusted by a heating element.

[0107] Final subs cc II240302PCT-2024063148.DOCX In this embodiment, the heating element can be provided locally (only for chamber 1) or globally for the entire system. The same applies, of course, to the cooling element, which can be provided either locally for chamber 1 or globally for the entire fluidics module / system.

[0108] Final subs cc II240302PCT-2024063148.DOCX

Claims

Patent claims 1. A centrifugal microfluidic cartridge module for operation in a centrifugal microfluidic device and / or centrifuge, comprising: a first chamber (1) configured to receive a liquid and / or gas and to subject the liquid and / or gas to a negative pressure and / or positive pressure relative to an initial pressure by means of pressure generation means (14); a second chamber (2); a third chamber (3); and a node (ZP) connected to the first, second, and third chambers (1, 2, 3) via a fluidic network, wherein the fluidic network comprises a first sub-channel (TK1) connecting the node (ZP) to the first chamber (1), a second sub-channel (TK2) connecting the node (ZP) to the second chamber (2), and a third sub-channel (TK3) connecting the node to the third chamber (3);wherein a second channel (K2) connects the second and third chambers (2, 3) to one another and opens into a radially outer region or at the radially outer end of the second chamber (2) and has at least one radially inwardly directed section; wherein the third sub-channel (TK3) has a section that extends further inward, viewed radially, than the second sub-channel (TK2).

2. Cartridge module according to claim 1, wherein the second sub-channel (TK2) has a higher fluidic resistance with respect to the liquid and / or the gas than the second channel (K2).

3. Cartridge module according to one of claims 1 or 2, wherein an apex of the second channel (K2) is located further radially outward than the apex of the inverse siphon formed by the first sub-channel (TK1) and second sub-channel (TK2), in particular Final subs cc II240302PCT-2024063148.DOCX in particular so that when filling the second channel (K2) a smaller maximum hydrostatic counterforce acts on the liquid and / or the gas than when filling the first sub-channel (TK1) and / or the second sub-channel (TK2).

4. Cartridge module according to claim 1, wherein the means for generating pressure (14) comprise means for tempering the liquid and / or gas, in particular heating and / or cooling means, which are designed to generate the overpressure by means of a temperature increase and the negative pressure by means of a temperature reduction.

5. Cartridge module according to one of the preceding claims, wherein a container in the first chamber (1) is opened due to an acceleration or a combination of hydrostatic force resulting from an acceleration and temperature increase.

6. Cartridge module according to one of the preceding claims, which has a control or is connected to a control which is designed to effect a pumping process of the liquid and / or gas from the first chamber (1) to the second chamber (2) by increasing a temperature in the first chamber (1) and / or reducing a rotation frequency of the cartridge module;or which has a control or is connected to a control which is designed to induce a pumping process of the liquid and / or gas from the first chamber (1) into the second (2) by an increase in temperature and / or a reduction in a rotation frequency of the cartridge module, wherein the pumping process is characterized in that the overpressure in the first chamber (1) is sufficiently great to convey the liquid over the apex of the inverse siphon formed by the first sub-channel (TK1) and the second sub-channel (TK2) and / or the overpressure is less than the pressure which would be necessary to convey the liquid over the apex of the inverse siphon formed by the first sub-channel (TK1) and the second sub-channel (TK2).

7. Cartridge module according to one of the preceding claims, which has a control or is connected to a control, wherein the control is designed to bring about a temperature reduction of the liquid and / or gas in the first chamber (1); or Final subs cc II240302PCT-2024063148.DOCX which has a control which is designed to bring about a temperature reduction of the liquid and / or gas in the first chamber (1) in order to create a negative pressure relative to an initial pressure in the first chamber (1), which negative pressure acts on the liquid and / or gas in the second chamber (2) via the first sub-channel (TK1), the second sub-channel (TK2) and via the first sub-channel (TK1), the third sub-channel (TK3) and the second channel (K2) or acts on the liquid and / or gas in the second chamber (2) via the first sub-channel (TK1), the third sub-channel (TK3) and the second channel (K2).

8. Cartridge module according to one of the preceding claims, wherein the third chamber (3) has a connection to the second channel (K2) which is arranged radially further inward than the maximum filling level of the third chamber (3).

9. Cartridge module according to one of the preceding claims, wherein the third chamber (3) and / or the second channel is arranged radially further outward than the second chamber (2) and / or the second partial channel (TK2).

10. Cartridge module according to one of the preceding claims, wherein the radially outer point of the second chamber (2) is arranged radially further outward than an opening from the second channel (2) into the third chamber (3). 1 1. Cartridge module according to one of the preceding claims, wherein the second chamber (2) has a connection to the second sub-channel (TK2), which is located in a radially outer region or at the outermost point of the second chamber (2).

12. Cartridge module according to one of the preceding claims, wherein the node is formed by a further chamber (4).

13. Cartridge module according to one of the preceding claims, wherein an additional chamber is provided between the node point and the second chamber (2).

14. Cartridge module according to claim 13, wherein the second sub-channel (TK2) is designed to retain the liquid and / or gas during transport of the liquid and / or gas from the first chamber (1) to the second chamber (2). Final subs cc II240302PCT-2024063148.DOCX 15. Cartridge module according to one of the preceding claims, wherein the means for generating pressure are designed to generate or vary the negative pressure and / or the positive pressure independently of rotation.

16. Cartridge module according to one of the preceding claims, wherein the node point (ZP) and / or the apex of the inverse siphon formed by the first sub-channel (TK1) and the second sub-channel (TK2) is located radially further inward than the first chamber (1) or the radially innermost liquid level in the first chamber (1).

17. Cartridge module according to one of the preceding claims, wherein the means for generating pressure act locally on the liquid and / or the gas in the first chamber or a negative or positive pressure on the liquid and / or the gas in the first chamber in relation to the liquid and / or the gas in the second chamber.

18. A method for operating a centrifugal microfluidic cartridge module according to any one of the preceding claims, comprising the following steps: Applying an overpressure to convey a liquid and / or gas from the first chamber (1) to the second chamber (2); and Applying a negative pressure to transport a liquid and / or gas from the second chamber (2) to the third chamber (3). Final subs cc II240302PCT-2024063148.DOCX

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