Centrifugal liquid multi-stage separation device and operation method therefor

Abstract

The present invention aims to provide a centrifugal liquid multi-stage separation device, comprising a body and a micro-channel structure, wherein the micro-channel structure is embedded in the body and comprises a sample loading section, a first density section, a temporary storage section and a second density section; the first density section is connected to the sample loading section and the temporary storage section; and the second density section is connected to the first density section and the temporary storage section. In the micro-channel structure, the sample loading section, the first density section, the temporary storage section and the second density section are mainly configured from inside to outside in sequence. In summary, the centrifugal liquid multi-stage separation device can separate liquid on the basis of the density of each component by controlling rotating speed parameters, and the conventional step of necessarily carrying out surface hydrophilic treatment on a flow channel wall is omitted on the basis of an oscillation release mode.

Description

Centrifugal liquid multi-stage separation device and operation method thereof

[0001] This application claims priority to Chinese patent application No. 202311422545.7, filed on October 30, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] At least one embodiment of the present disclosure relates to a centrifugal liquid separation device and an operating method thereof, and more particularly to a centrifugal liquid separation device with a multi-stage separation design and an operating method thereof. Background Art

[0003] There are many types of biological specimens. For example, plasma is an important biological specimen that can provide a lot of physiological or clinical information, allowing medical personnel or testing units to quickly understand the individual's physical condition.

[0004] However, to achieve the separation of biological specimens, for example, most blood tests require the separation of whole blood to obtain the desired test items (such as blood coagulation tests). In view of this, research and development of separation technologies has never stopped. For example, the development of a method with good separation effect and fast speed to separate sample targets such as platelets or plasma from whole blood is being developed.

[0005] Traditionally, biological specimens are separated by utilizing the centrifugal force generated by high-speed centrifuge rotation to separate test targets with different specific gravities within a test tube. However, the sample pre-treatment process and post-separation equipment cleaning are time-consuming. Furthermore, even though most tests require only a small amount of sample, traditional separation procedures still require a large amount of blood to obtain the sample.

[0006] Given the recent boom in biomedical testing device technology, related separation techniques have also been increasingly advanced. For example, centrifugal microfluidics (also known as lab-on-a-chip) utilizes microfluidic structure design in conjunction with electrophoresis or dielectrophoresis to separate liquids (such as blood). However, the corresponding testing conditions are not entirely conducive to obtaining intact samples. For example, blood samples must first be diluted and then placed in a high-voltage environment for separation. These basic steps may lead to deterioration or contamination of the final sample.

[0007] Therefore, an object of the present invention is to provide a method for separating liquids (such as blood) efficiently with simple operation and without requiring high voltage.

[0008] Summary of the Invention

[0009] To address at least one of the aforementioned issues, some embodiments of the present disclosure provide a centrifugal multi-stage liquid separation device and operating method thereof. Specifically, the device features a multi-stage centrifugal liquid separation device and operating method thereof, which offer the advantages of a simple operation process and high cleaning efficiency. The device utilizes a controlled speed parameter to separate the density of liquid components. Furthermore, by combining this with an oscillating release method, the conventional step of treating the channel walls for hydrophilicity is eliminated. In some cases, the operating method can even achieve liquid separation by operating at only two speeds: high and low.

[0010] At least one embodiment of the present disclosure is a centrifugal multi-stage liquid separation device comprising a main body and a microfluidic structure. The microfluidic structure is embedded in the main body and includes a sample loading section, a first density section, a temporary storage section, and a second density section. The first density section is connected to the sample loading section; the second density section is connected to the first density section. In the aforementioned microfluidic structure, the main sections arranged outward from a rotation center are, in order, the sample loading section, the first density section, the temporary storage section, and the second density section.

[0011] At least one embodiment of the present disclosure is a centrifugal liquid multi-stage separation method. The operating method includes providing the centrifugal liquid multi-stage separation device; providing a liquid-to-sample loading section of a microfluidic structure; driving the main body to rotate at a high speed, causing the liquid to enter a first density section and a second density section, and retaining the higher-density portion of the liquid in the second density section due to centrifugal force; then switching the rotation direction of the main body to generate oscillation, allowing the lower-density portion of the liquid to break through the restriction of surface tension and pass through the first flow channel into a first storage section; and finally, continuously oscillating the main body until the remaining liquid in the first density section is emptied into the first storage section, thereby sequentially obtaining a first separated liquid and a second separated liquid.

[0012] At least one embodiment of the present disclosure is a centrifugal multi-stage liquid separation method. The operating method includes providing the centrifugal multi-stage liquid separation device and a second flow channel connected to the first density section; providing a liquid-to-microchannel loading section; driving the body to rotate at a high speed to allow the liquid to enter the first density section and the second density section; and retaining the higher density portion of the liquid in the second density section due to centrifugal force; then switching the direction of the body to allow the lower density portion of the liquid to break through the surface tension and flow into a second storage section through the second flow channel; finally, switching the direction of the body again to allow the lower density portion of the remaining liquid to break through the surface tension and flow into the first storage section through the first flow channel, and maintaining rotation until the remaining liquid in the first density section is completely drained, thereby sequentially obtaining a first separated liquid, a second separated liquid, and a third separated liquid.

[0013] At least one embodiment of the present disclosure is a centrifugal multi-stage liquid separation method. The method comprises providing the centrifugal multi-stage liquid separation device and a second flow channel connected to the first density section; providing a liquid-to-microfluidic section for loading a sample into the microfluidic structure; rotating a body at a high speed to allow the liquid to enter the first and second density sections, such that the higher density portion of the liquid is retained in the second density section due to centrifugal force; then, reducing the rotation speed until the body stops rotating, allowing the lower density portion of the liquid to wet the second flow channel through capillary action; after wetting is complete, increasing the rotation speed of the body again, allowing the lower density portion of the liquid to flow through the second flow channel into a second storage section; then, switching the rotation direction of the body to generate oscillation, allowing the lower density portion of the remaining liquid to gradually wet and pass through the first flow channel through the oscillation; finally, increasing the rotation speed of the body again, allowing the lower density portion of the remaining liquid to flow through the first flow channel into the first storage section, and continuing the rotation until the remaining liquid in the first density section is completely drained, thereby sequentially obtaining a first separated liquid, a second separated liquid, and a third separated liquid.

[0014] At least one embodiment of the present disclosure is characterized in that the first flow channel and the second flow channel are liquid flow channels that have not been subjected to hydrophilic modification treatment.

[0015] At least one embodiment of the present disclosure is a centrifugal liquid multi-stage separation method. The operation method includes providing the centrifugal liquid multi-stage separation device, a second flow channel and a distribution structure, wherein the second flow channel is connected to the first density section and the distribution structure is connected to the second flow channel, wherein the distribution structure has a distribution section, at least a certain amount chamber and at least one reaction chamber, the distribution section is connected to the quantitative chamber and the quantitative chamber is connected to the reaction chamber; providing a liquid to the microchannel structure of the sample addition section; driving the body to rotate at a high speed to allow the liquid to enter the first density section and the second density section, so that the part with higher density in the liquid stays in the second density section due to the centrifugal force; then, switching the direction of the body and reducing the speed to a low speed threshold value, so that the lower density portion of the first separated liquid can climb and enter the distribution section and the at least one certain volume chamber through the second flow channel; after the quantitative chamber is filled, the rotation speed is adjusted to a high speed threshold, so that the second separated liquid in the at least one certain volume chamber can enter the at least one reaction chamber to perform a reaction; finally, the rotation direction of the body is switched again, so that the lower density portion of the first separated liquid remaining in the first density section can enter a first storage section through the first flow channel, and the rotation is maintained until the remaining liquid in the first density section is completely drained, so as to obtain a first separated liquid, a second separated liquid and a third separated liquid in sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present disclosure is further described below with reference to the accompanying drawings and embodiments:

[0017] FIG1 is a schematic diagram of a centrifugal liquid multi-stage separation device according to some embodiments of the present disclosure.

[0018] FIG2 is another schematic diagram of a centrifugal liquid multi-stage separation device according to some embodiments of the present disclosure.

[0019] FIG3 is another schematic diagram of a centrifugal liquid multi-stage separation device according to some embodiments of the present disclosure, used to explain the connection relationship of the components in FIG1 and FIG2 .

[0020] FIG4 is a flow chart of a centrifugal liquid multi-stage separation method according to some embodiments of the present disclosure.

[0021] FIG5 is another flow chart of the centrifugal liquid multi-stage separation method according to some embodiments of the present disclosure.

[0022] FIG6 is another flow chart of the centrifugal liquid multi-stage separation method according to some embodiments of the present disclosure.

[0023] 7 to 14 are schematic diagrams of centrifugal multi-stage liquid separation devices corresponding to the centrifugal multi-stage liquid separation methods according to some embodiments of the present disclosure.

[0024] FIG15 is another schematic diagram of a centrifugal liquid multi-stage separation device according to some embodiments of the present disclosure.

[0025] FIG16 is another flow chart of the centrifugal liquid multi-stage separation method according to some embodiments of the present disclosure.

[0026] 17 to 24 are another schematic diagram of a centrifugal multi-stage liquid separation device corresponding to the centrifugal multi-stage liquid separation method according to some embodiments of the present disclosure.

[0027] Reference numerals:

[0028] Main body 10; microfluidic channel structure 20; sample loading section 21; first density section 22; second density section 23; temporary storage section 24; sample loading hole 211; air hole 212; first flow channel 221; second flow channel 223; reflux structure 225; first bend 221a; first storage section 221b; second bend 223a; second storage section 223b; liquid 60, 70; high-density portion 61, 71; medium-density portion 62, 72; low-density portion 63, 73; first interface f1; second interface f2; third interface f3; fourth interface f4; distribution structure 30; distribution section 31; quantitative chamber 311; reaction chamber 313; waste liquid chamber 315. DETAILED DESCRIPTION

[0029] At least one embodiment of the present disclosure relates to a centrifugal liquid separation device and an operating method thereof, and more particularly to a centrifugal liquid separation device with a multi-stage separation design and an operating method thereof.

[0030] Please refer to FIG1 for a schematic diagram of a centrifugal liquid multi-stage separation device according to some embodiments of the present disclosure. The centrifugal liquid multi-stage separation device includes a main body 10 and a microfluidic structure 20. The main body 10 is used as a medium to drive and control the movement of the microfluidic structure 20. In this embodiment, the microfluidic structure 20 is embedded in the main body 10. The microfluidic structure 20 has a sample loading section 21, a first density section 22, a second density section 23 and a temporary storage section 24, which are used to perform various tests. In addition, as shown in FIG1 , the configuration of the microfluidic structure 20 is the sample loading section 21, the first density section 22, the temporary storage section 24 and the second density section 23 from a rotation center outward. The main body 10 in FIG1 can be a symmetrical disc with a circular, square, or polygonal shape. The material can be acrylic (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polydimethylsilicon (PDMS), silicone, rubber, plastic, glass, or a combination thereof. The main body 10 can be removably placed in a centrifuge or rotary motor for centrifugal operation. When the main body 10 is subjected to force, it drives the microfluidic structure 20 to operate. The sample loading section 21 in FIG1 includes a sample loading hole 211 and an air hole 212 . The sample loading hole 211 and the air hole 212 may be circular or polygonal in shape. One side of the first density section 22 is connected to the sample loading section 21 , and the other side of the first density section 22 is connected to the second density section 23 . The first density section 22 has a first flow channel 221 . The first flow channel 221 bends away from the sample loading section 21 to form a first bend 221 a to buffer the flow rate of the liquid sample in the first flow channel 221 .

[0031] The sample loading section 21 in FIG1 can accommodate a liquid, such as a sample, a buffer solution, a wash buffer, a reagent, or a solvent. In some embodiments of the present disclosure, the case where the liquid loaded is a blood solution is used as an example for illustration, but the present disclosure is not limited thereto.

[0032] FIG2 is another schematic diagram of a centrifugal multi-stage liquid separation device according to some embodiments of the present disclosure. FIG2 differs from FIG1 in that the centrifugal multi-stage liquid separation device may further include a second flow channel 223. The second flow channel 223 is connected to the first density section 22 and the temporary storage section 24. The second flow channel 223 bends away from the sample loading section 21 to form a second bend 223a, which is used to buffer the flow velocity of the liquid in the second flow channel 223. In this embodiment, the second flow channel 223 extending toward the sample loading section 21 should be higher than the first flow channel 221 to form a height difference (i.e., the second flow channel 223 is closer to the sample loading section 21 than the first flow channel 221).

[0033] The first bend 221a or the second bend 223a in Figures 1 and 2 can be used to prevent liquid from prematurely passing through the first flow channel 221 or the second flow channel 223 due to centrifugal force before a predetermined condition occurs. For example, when the main body 10 of the centrifugal multi-stage liquid separation device is in operation, the liquid is designed to be retained in the first flow channel 221 or the second flow channel 223 based on the properties of capillaries. However, when the rotational speed of the main body 10 is increased so that the centrifugal force is greater than the surface tension generated by the liquid, the liquid begins to rise and pass through the first bend 221a or the second bend 223a due to the force generated by the angular velocity of the rotational speed.

[0034] According to the microchannel structure 20 in the aforementioned embodiment (as shown in Figures 1 and 2), the widths of the first flow channel 221 and the second flow channel 223 are between 0.1 mm and 1.0 mm; the first flow channel 221 and the second flow channel 223 form an angle between 30 degrees and 80 degrees with the normal direction of the rotation center and the direction to the junction of the first flow channel 221 and the second flow channel 223 and the first density section 22.

[0035] FIG3 is another schematic diagram of a centrifugal liquid multi-stage separation device according to some embodiments of the present disclosure, which is used to explain the distribution of components in FIG1 and FIG2. In the first density section 22 of FIG3, the first density section 22 includes at least one reflux structure 225. The reflux structure 225 may be heart-shaped or other structural type with two symmetrical arc-shaped edges, which is not limited here. In the embodiment of FIG3, the function of the reflux structure 225 is mainly used to regulate the flow direction of the liquid. For example, when the liquid flows to the periphery of the first density section 22 due to centrifugal force simulating gravity, the shape design of the reflux structure 225 will guide the liquid to turn downward to form a single direction diversion, so as to achieve the effect of regulating the flow direction of the liquid. As shown in FIG3, the first density section 22 is also connected to a temporary storage section 24, which is connected to the external atmospheric environment through the temporary storage section 24, thereby reducing the resistance caused by air pressure when the liquid moves in the first density section 22. In FIG. 1 , FIG. 2 and FIG. 3 , the temporary storage section 24 is configured to communicate with the first density section 22 and the first flow channel 221 for guiding the liquid in the first density section 22 to the first flow channel 221 .

[0036] Referring to Figures 1 and 2 , after centrifugation, the liquid flows through the first flow channel 221 and / or the second flow channel 223 into the storage section (as shown in Figure 3 ). For ease of illustration, the storage section connected to the first flow channel 221 is defined as the first storage section 221b, and the storage section connected to the second flow channel 223 is defined as the second storage section 223b. Furthermore, the storage section can be further divided into multiple storage units (not shown) as needed, and each storage unit can be isolated from another to further separate the liquid.

[0037] As shown in Figure 3, the connection between the first flow channel 221 and the first density section 22 through the temporary storage section 24 is called the first interface f1, while the connection between the first flow channel 221 and the first storage section 221b is called the second interface f2. A first bend 221a is provided between the first interface f1 and the second interface f2. Conversely, the connection between the second flow channel 223 and the first density section 22 is called the third interface f3, while the connection between the second flow channel 223 and the second storage section 223b is called the fourth interface f4. A second bend 223a is provided between the third interface f3 and the fourth interface f4.

[0038] The height differences between the first and second interfaces f1 and f2, the first and third interfaces f3, and the third and fourth interfaces f3 and f4 affect the speed. When centrifugal force is used as the driving source, the speed is generated by a centrifuge or a rotary motor and drives the body 10 to rotate. The speed threshold depends on the surface tension of the liquid temporarily stored in the first and second flow channels 221 and 223 (i.e., when the centrifugal force acting on the liquid is greater than its surface tension, the liquid begins to flow into the first and second storage sections 221b and 223b).

[0039] To facilitate understanding of the principle of the actual application of the aforementioned speed threshold in the embodiment, the following will be described in sequence with reference to the schematic diagrams of the aforementioned Figures 1-3 in Figures 4, 5, 6, and 7-14.

[0040] First, FIG4 is a flow chart of a centrifugal liquid multi-stage separation method according to some embodiments of the present disclosure. The method includes providing a centrifugal multi-stage liquid separation device (step (a1)). In this embodiment, the centrifugal multi-stage liquid separation device shown in FIG. 1 is used; providing a liquid to the sample loading section 21 (step (a2)); rotating the body 10 at a rotational speed. Under the action of centrifugal force, the less dense portion of the liquid (i.e., a first separated liquid) will be retained in the first density section 22 and the temporary storage section 24 and stagnated in the first flow channel 221 due to its surface tension (step (a3)); and the more dense portion will eventually enter the second density section 23. After the above steps are completed, adjusting the direction of the body 10 by switching the direction of the body 10 once, multiple times, or continuously, so that the less dense portion of the first separated liquid climbs through the first bend 221a to a second interface f2 (as shown in FIG. 3) (step (a4)); finally, increasing the rotational speed to the speed threshold so that the less dense portion of the first separated liquid breaks through its own surface tension and enters the first storage section 221b (as shown in FIG. 3) to form a second separated liquid (step (a5)).

[0041] Among them, the relative size of the liquid density mainly depends on the composition of the liquid. For example, when the liquid is blood, the part with lower density (i.e. the first separated liquid) may be plasma; and the part with higher density may be a collection of red blood cells, white blood cells and platelets.

[0042] The speed threshold is determined by the surface tension of the less dense portion of the first separated liquid. In some embodiments, the rotational speed can actually include a plurality of different drive speeds, which can be arbitrarily varied in accordance with the embodiment and detection content and in combination with the speed threshold, and this disclosure is not limited thereto.

[0043] FIG5 is another flow chart of the centrifugal liquid multi-stage separation method of some embodiments of the present disclosure. The method comprises providing a centrifugal liquid multi-stage separation device (step (b1)). In this embodiment, the centrifugal liquid multi-stage separation device of FIG2 is used; providing a liquid to the sample adding section 21 (step (b2)); rotating the main body 10 in a positive direction at a first speed so that the liquid retains the lower density portion thereof in the first density section 22 and the temporary storage section 24 by the centrifugal force to form a first separation liquid, and generates surface tension in the first flow channel 221 and the second flow channel 223 to prevent the first separation liquid from moving forward, and the higher density portion will eventually enter the second density section 23 (step (b3)); switching the direction of the main body 10 so that the first separation The lower density portion of the liquid is able to break through the limitation of its surface tension and enter a second storage section 223b (as shown in FIG3 ) through the second flow channel 223, forming a second separated liquid (step (b4)); the main body 10 is continuously rotated at the high speed of the rotation speed until the first separated liquid remaining in the first density section 22 is further separated by sedimentation according to density (step (b5)); finally, the direction of the main body 10 is switched again, so that the lower density portion of the remaining first separated liquid is able to break through the limitation of its own surface tension and enter a first storage section 221b (as shown in FIG3 ) through the first flow channel 221, forming a third separated liquid (step (b6)). It should be noted that in the actual application of the present disclosure, the method described can selectively perform step (b5) after the separation step (b4) based on the residual state or condition of the first separated liquid.

[0044] Among them, the relative size of the liquid density mainly depends on the composition of the liquid. For example, when the liquid is blood, the part with lower density in the liquid (i.e., the first separated liquid) may be plasma; the part with lower density in the first separated liquid may be a serum mixture; and the part with lower density in the remaining first separated liquid may be serum.

[0045] In addition, in some embodiments, the method can increase the rotational speed to a speed threshold in step (b4), so that the less dense parts of the first separated liquid can easily break through their surface tension limitations due to the force generated by the rotational speed. In this case, in step (b6), the rotational speed can also be increased again to a speed greater than the aforementioned speed threshold, so that the less dense parts of the remaining first separated liquid can more easily break free from their surface tension limitations. At this time, the so-called speed threshold is determined by the surface tension of the less dense parts of the first separated liquid and the less dense parts of the remaining first separated liquid. In some embodiments, the rotational speed can actually include a plurality of different driving speeds, which can be arbitrarily changed in accordance with the embodiment and detection content in combination with the speed threshold, and the present disclosure does not limit them.

[0046] FIG6 is another flow chart of a centrifugal liquid multi-stage separation method according to some embodiments of the present disclosure. The method comprises providing a centrifugal liquid multi-stage separation device (step (c1)). In this embodiment, the centrifugal liquid multi-stage separation device of FIG2 is used; providing a liquid to the sample adding section 21 (step (c2)); rotating the main body 10 at a rotation speed so that the liquid retains the lower density portion thereof in the first density section 22 and the temporary storage section 24 by the centrifugal force to form a first separation liquid, and generates surface tension in the first flow channel 221 and the second flow channel 223 to prevent the first separation liquid from advancing, and the higher density portion will eventually enter the second density section 23 (step (c3)); reducing the rotation speed until the main body 10 stops rotating, so that the first separation liquid wets the second flow channel 223 by capillary phenomenon (step (c4)); restarting and increasing the rotation speed to a speed threshold so that the first separation liquid The lower density portion enters a second storage section 223b (as shown in FIG3 ) through the second flow channel 223 to form a second separation liquid (step (c5)); the main body 10 is continuously rotated until the first separation liquid remaining in the first density section 22 is further separated by sedimentation according to density (step (c6)); the direction of the main body 10 is adjusted to switch single, multiple or continuous rotations so that the lower density portion of the remaining first separation liquid climbs through the first bend 221a through oscillation (step (c7)); after the infiltration is completed, the rotation speed is increased again until it is greater than the speed threshold, so that the lower density portion of the remaining first separation liquid can break through the limitation of its surface tension and enter a first storage section 221b (as shown in FIG3 ) through the first flow channel 221 to form a third separation liquid (step (c8)).

[0047] Among them, the speed threshold depends on the lower density part in the first separation liquid; and the surface tension of the lower density part in the residual first separation liquid. In some embodiments, the rotational speed can actually include a plurality of different driving speeds, which can be arbitrarily changed in accordance with the embodiment and detection content in combination with the speed threshold, and the present disclosure does not limit it.

[0048] The inner surface of the second flow channel 223 must be made of a hydrophilic material or be treated to be hydrophilic.

[0049] Furthermore, in some embodiments, the method may selectively perform step (c6) to sediment and form a low-density portion 63 therein according to the residual state or condition of the medium-density portion 62 after the separation step (c5).

[0050] In some embodiments, the oscillation method can be selected and executed depending on the actual liquid separation conditions, and can provide liquid action force and reaction force regardless of the type of flow channel (hydrophilically treated / not hydrophilically treated) of the first flow channel 221 or the second flow channel 223, so that the liquid can break through the surface tension limitation of the flow channel (the first flow channel 221 or the second flow channel 223) due to the action force; and will not break through the surface tension limitation of the other flow channel (the second flow channel 223 or the first flow channel 221) due to the reaction force.

[0051] Figures 7 to 14 are schematic diagrams of centrifugal multi-stage liquid separation devices corresponding to the operating methods of the centrifugal multi-stage liquid separation devices according to some embodiments of the present disclosure. Figures 7 to 14 illustrate the movement and distribution of liquid within the microfluidic structure 20 of Figure 2 during operation (i.e., steps (c2) to (c8) of Figure 6). To facilitate the description of liquid separation, the portion of the liquid with a higher density is referred to as the high-density portion 61; the portion of the liquid with a lower density (i.e., the first separated liquid) is referred to as the medium-density portion 62; and the portion of the first separated liquid with a lower density after sedimentation separation is referred to as the low-density portion 63.

[0052] Step (c2): When a liquid 60 is injected into the microfluidic channel structure 20 of Figure 2 , the distribution is shown in Figure 7 . Referring to the embodiment of Figure 7 in conjunction with the structure of Figure 3 , it can be seen that Figure 7 is identical to the structure of Figure 3 . For experiments requiring liquid quantification prior to testing, the microfluidic channel structure 20 disclosed herein can be optionally equipped with a metering device / structure based on actual experimental requirements, in conjunction with the use of the sample addition section 21 .

[0053] Step (c3): After the liquid 60 is subjected to strong centrifugal force and is sent into the first density section 22 and the second density section 23, it exhibits the distribution shown in Figure 8 . In the embodiment of Figure 8 , the liquid 60 includes a high-density portion 61 and a medium-density portion 62 (for example, the high-density portion 61 may be blood cells, and the medium-density portion 62 may be plasma).

[0054] Step (c3): Under the continued action of centrifugal force, the liquid in the first density section 22 and the second density section 23 separates due to the centrifugal force. Based on the principle of buoyancy, the high-density portion 61 sinks to the second density section 23, while the medium-density portion 62 floats above the first density section 22, resulting in the distribution shown in Figure 9. In Figure 9, the first density section 22 and the medium-density portion 62 in the first flow channel 221 and the second flow channel 223 have the same liquid level due to the connecting pipe effect created by centrifugal force simulating gravity. The first curved portion 221a and the second curved portion 223a are primarily provided to create the aforementioned connecting pipe effect.

[0055] Step (c4): When the rotation speed is reduced until the main body 10 stops rotating, the medium-density portion 62 of the liquid 60 will gradually infiltrate and fill the second flow channel 223 based on the capillary phenomenon as shown in Figure 10, and finally stay at the junction of the second flow channel 223 and the second storage section 223b due to the surface tension of the medium-density portion 62 itself, that is, stay at the fourth interface f4 of the embodiment shown in Figure 3.

[0056] Step (c5): In Figure 11, since the rotating body 10 is restored and the rotation speed is increased to a speed threshold to regenerate a strong centrifugal force, the medium-density portion 62 uses the force generated by the strong centrifugal force to break through the surface tension at the fourth interface f4 and flows into the second storage section 223b, forming a first separation of liquid, wherein the speed threshold depends on the surface tension value of the smaller density in the medium-density portion 62 at the fourth interface f4.

[0057] Step (c6): Then, as shown in FIG12 , the main body 10 is allowed to maintain the rotational speed and continue to rotate, so that the remaining medium-density portion 62 (i.e., the medium-density portion 62 with a higher density) in the first density section 22 is again settled and separated due to centrifugal force simulating gravity, wherein the smaller density is defined as the low-density portion 63.

[0058] Step (c7): In Figure 13 , the oscillation caused by the back-and-forth rotation of the main body 10 causes the low-density portion 63 to gradually penetrate and pass through the first flow channel 221. Similar to Figure 10 , the low-density portion 63 eventually settles at the junction of the first flow channel 221 and the first storage section 221b due to surface tension, i.e., at the second interface f2 described in the embodiment of Figure 3 . In Figure 14 , when the main body increases its rotational speed again, using strong centrifugal force to overcome the surface tension at the second interface f2, the low-density portion 63 in the first density section 22 flows into the first storage section 221b, and a siphon effect forms a discharge flow until the low-density portion 63 in the first density section 22 is completely drained. During this process, the high-density portion 61 and the higher-density portion of the medium-density portion 62, after sedimentation separation, remain in the second density section 23 due to gravity.

[0059] Step (c8): In the aforementioned embodiment, the rotational speed of the rotating body 10 in FIG. 14 must be at least greater than the aforementioned speed threshold so that the force generated thereby can break through the surface tension of the low-density portion 63 and enter the first storage section 221b. In this embodiment, the first flow channel 221 can be a liquid flow channel that has not been hydrophilized, and the second flow channel 223 can be a liquid flow channel that has undergone a localized surface hydrophilization treatment using oxygen plasma. The tube wall material can be polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polydimethylsilicon (PDMS), silicone, rubber, or plastic, such as polymethylmethacrylate (PMMA).

[0060] FIG15 is another schematic diagram of a portion of a centrifugal liquid multi-stage separation device according to some embodiments of the present disclosure. The difference between FIG15 and FIG2 and FIG3 is that the centrifugal liquid multi-stage separation device further includes a distribution structure 30 connected to the aforementioned second flow channel 223. The distribution structure 30 is configured so that the microfluidic structure 20 can directly react the separated liquid with a predetermined reagent. The distribution structure 30 of FIG15 comprises a distribution section 31; at least a certain amount of chamber 311 for quantitatively measuring the liquid to be reacted with the reagent; at least one reaction chamber 313 for accommodating a predetermined reagent; and at least one waste liquid chamber 315, wherein the distribution section 31 is connected to the quantitative chamber 311; the packaging section 31 is connected to the waste liquid chamber 315; and the quantitative chamber 311 is connected to the reaction chamber 313; and the distribution structure 30 is arranged from the center of rotation outward in the order of the distribution section 31, the quantitative chamber 311, and the reaction chamber 313. The reagents can be provided in the form of freeze-dried, freeze-dried powder, freeze-dried pellets or reagent packs; and can be reconstituted when in contact with a liquid (such as the separated liquid).

[0061] Please refer to Figures 2 and 16. Figure 16 is another flow chart of the centrifugal liquid multi-stage separation method of some embodiments of the present disclosure. The method includes providing a centrifugal liquid multi-stage separation device (step (d1)). In this embodiment, the centrifugal liquid multi-stage separation device of Figure 15 is used; providing a liquid to the sample addition section 21 (step (d2)); rotating the main body 10 at a rotation speed so that the liquid retains the lower density portion in the first density section 22 and the temporary storage section 24 by centrifugal force to form a first separation liquid, and generates surface tension in the first flow channel 221 and the second flow channel 223 to prevent the first separation liquid from moving forward, and the higher density portion will eventually enter the second density section 23 (step (d3)); switching the direction of the main body 10 and reducing the rotation speed to a low speed threshold so that the lower density portion in the first separation liquid is retained. The first portion of the liquid is allowed to climb and enter the distribution section 31 and the quantitative chamber 311 through the second flow channel 223 to form a second separation liquid, and the other portion enters the waste liquid chamber 315 (step (d4)); the rotation speed is adjusted to a high speed threshold so that the second separation liquid in the quantitative chamber 311 can enter the reaction chamber 313 to perform a reaction (step (d5)); the main body 10 is continuously rotated until the first separation liquid remaining in the first density section 22 is further separated by sedimentation according to density (step (d6)); the direction of the main body 10 is switched again so that the portion with lower density in the remaining first separation liquid can enter a first storage section 221b through the first flow channel 221 to form a third separation liquid (step (d7)).

[0062] The low speed threshold is determined by the surface tension of the less dense portion of the first separation liquid and the remaining less dense portion of the first separation liquid (for example, in this embodiment, the low speed threshold may be 1000 (rpm)). Of course, in some embodiments, this low speed threshold, like the aforementioned speed threshold, may actually include a plurality of different drive speeds, as long as the speed value is lower than the speed value, and this disclosure is not limited thereto. The high speed threshold is determined by the surface tension of the second separation liquid (for example, in this embodiment, the high speed threshold may be 5000 (rpm)). Similar to the low speed threshold, the high speed threshold may be any combination of drive speeds, as long as the speed value is higher than the low speed threshold.

[0063] In addition, in some embodiments, the rotational speed after switching the direction can be increased to another speed threshold in step (d7), so that the less dense parts of the first separated liquid can be more easily broken through the surface tension limitation in the first flow channel 221 by the force generated by the rotational speed.

[0064] Furthermore, in some possible embodiments, the method may selectively perform step (d6) to settle the higher density portion of the first separation liquid in the first density section 22 after the reaction step (d5) based on the residual state or condition of the first separation liquid in the first density section 22.

[0065] Figures 17 to 24 are another schematic diagram of a centrifugal multi-stage liquid separation device corresponding to the operating method of the centrifugal multi-stage liquid separation device according to some embodiments of the present disclosure. Figures 17 to 24 illustrate the movement and distribution of liquid within the microfluidic structure 20 of Figure 15 during operation (i.e., steps (d2) to (d7) of Figure 16). To facilitate the description of the liquid separation, the portion of the liquid with a higher density is referred to as the high-density portion 71; the portion of the liquid with a lower density (i.e., the first separated liquid) is referred to as the medium-density portion 72; and the portion of the first separated liquid with a lower density after sedimentation separation is referred to as the low-density portion 73.

[0066] Step (d2): When a liquid 70 is injected into the microfluidic channel structure 20 of Figure 15 , the distribution is shown in Figure 17 . For experiments requiring liquid quantification prior to the test, the microfluidic channel structure 20 of the present disclosure can be optionally equipped with a metering device / structure based on actual experimental requirements by utilizing the sample addition section 21 .

[0067] Step (d3): After the liquid 70 is subjected to strong centrifugal force and is sent into the first density section 22 and the second density section 23, it exhibits the distribution shown in Figure 18. In the embodiment of Figure 18, the liquid 70 includes a high-density portion 71 and a medium-density portion 72 (for example, the high-density portion 71 may be blood cells, and the medium-density portion 72 may be plasma).

[0068] Step (d3): Under the continued action of centrifugal force, the liquid in the first density section 22 and the second density section 23 separates due to the centrifugal force. Based on the principle of buoyancy, the high-density portion 71 sinks to the second density section 23, while the medium-density portion 72 floats above the first density section 22, resulting in the distribution shown in Figure 19. In Figure 19, the first density section 22 and the medium-density portion 72 in the first flow channel 221 and the second flow channel 223 have the same liquid level due to the connecting pipe effect created by centrifugal force simulating gravity. The first curved portion 221a and the second curved portion 223a are primarily provided to create the aforementioned connecting pipe effect.

[0069] Step (d4): When the main body 10 is switched to a low speed threshold, the medium-density portion 72 of the liquid 70 begins to rise as shown in FIG20 and enters the distribution section 31 and the metering chamber 311 in sequence through the second flow channel 223, ultimately filling each metering chamber 311. Due to its surface tension, the medium-density portion 72 remains at the junction of the metering chamber 311 and the reaction chamber 313. At this point, the remaining portion of the medium-density portion 72 after filling enters the waste liquid chamber 315. The low speed threshold in step (d4) depends on the surface tension of the medium-density portion 72 at the second flow channel 223 and the junction.

[0070] Step (d5): In FIG21 , the rotational speed is adjusted to a high speed threshold to regenerate a strong centrifugal force. The medium-density portion 72 in the quantitative chamber 311 utilizes the force generated by the strong centrifugal force to break through its surface tension at the interface and enter the reaction chamber 313 to perform a reaction. The reaction is carried out in a suitable reagent based on the properties of the liquid 70. This reagent can be provided in a lyophilized form, a lyophilized powder, or a reagent package and is pre-stored in the reaction chamber 313. It should be noted that the high speed threshold in step (d5) depends on the surface tension of the medium-density portion 72 at the interface.

[0071] Step (d6): Then, as shown in FIG22 , the main body 10 is allowed to maintain the rotational speed and continue to rotate, so that the remaining medium-density portion 72 (i.e., the medium-density portion 72 with a higher density) in the first density section 22 is again settled and separated due to centrifugal force simulating gravity, wherein the smaller density portion is defined as the low-density portion 73.

[0072] Step (d7): In Figure 23 , the rotation direction of the main body 10 is reversed again. Similar to Figure 20 , the low-density portion 73 will eventually remain at the junction of the first flow channel 221 and the first storage section 221b due to surface tension. In Figure 24 , when the main body further increases its rotational speed, the low-density portion 73, due to the strong centrifugal force, will break through the surface tension at the junction of the first flow channel 221 and the first storage section 221b and flow into the first storage section 221b. A siphon effect will then form a discharge flow until the low-density portion 73 in the first density section 22 is completely drained. During this process, the high-density portion 71 in the second density section 23 and the medium-density portion 72 in the distribution structure 30 are retained therein due to gravity.

[0073] The above embodiments are merely illustrative of the technical ideas and features of the present disclosure, and are intended to enable persons skilled in the art to fully understand the contents of the present disclosure and implement them accordingly. They are not intended to limit the scope of the claims of the present disclosure. Equivalent changes or modifications based on the spirit disclosed in the present disclosure should still be included in the scope of the claims of the present disclosure.

Claims

1. A centrifugal liquid multi-stage separation device, comprising: A body and a microfluidic structure, wherein the microfluidic structure is embedded in the body, and the microfluidic structure comprises: A sample adding section having a sample adding hole for a liquid to enter; a first density section connected to the sample adding section, the first density section having a first flow channel, the first flow channel being bent in a direction away from the sample adding section to form a first bending portion; a temporary storage section, connected to the first density section and the first flow channel; and a second density section connected to the first density section and the temporary storage section; The microchannel structure is arranged from a rotation center outwards in order of the sample adding section, the first density section, the temporary storage section and the second density section.

2. The centrifugal liquid multi-stage separation device according to claim 1, wherein: The microchannel structure also includes a second channel connected to the first density section. The second channel is bent in a direction away from the sample adding section to form a second bent portion.

3. The centrifugal liquid multi-stage separation device according to claim 1 or 2, wherein: The first density section also includes at least one return flow structure.

4. The centrifugal liquid multi-stage separation device according to claim 2, wherein: The microfluidic structure also includes: a distribution structure connected to the second flow channel, the distribution structure having a distribution section; at least one metering chamber in communication with the dispensing section; and at least one reaction chamber, connected to the at least one volume chamber; The distribution structure is arranged from the rotation center outward in order to include the distribution section, the at least one volume chamber, and the at least one reaction chamber.

5. The centrifugal liquid multi-stage separation device according to claim 4, wherein: The distribution structure further includes at least one waste liquid chamber, which is communicated with the distribution section.

6. A centrifugal liquid multi-stage separation method, comprising: (a1) providing a centrifugal liquid separation device as claimed in claim 1; (a2) injecting the liquid into the sample adding section; (a3) driving the body to rotate at a speed such that the liquid retains the lower density portion in the first density section by centrifugal force to form a first separation liquid, and the other portions enter the second density section; (a4) after the above steps are completed, by switching the direction of the body once or multiple times continuously, the part with lower density in the first separated liquid is caused to oscillate and climb and pass through the first bending portion; and (a5) adjusting the body to rotate at a high speed until the liquid is drained from the first density section and enters a first storage section to form a second separation liquid.

7. A centrifugal liquid multi-stage separation method, comprising: (b1) providing a centrifugal liquid separation device as claimed in claim 2; (b2) injecting the liquid into the sample adding section; (b3) driving the body to rotate at a speed such that the liquid retains the lower density portion thereof in the first density section, the temporary storage section, the first flow channel and the second flow channel by centrifugal force, thereby forming a first separation of the liquid, and the other portions of the liquid enter the second density section; (b4) switching the direction of the body so that the less dense portion of the first separated liquid can rise and enter a second storage section through the second flow channel to form a second separated liquid; (b5) continuing to rotate the body at the high speed until the first speed separated liquid remaining in the first density section is further separated by sedimentation according to density; and (b6) switching the direction of the body again so that the smaller density of the remaining first separated liquid is The liquid is able to break through the limitation of surface tension and enter a first storage section through the first flow channel to form a third separation liquid.

8. A centrifugal liquid multi-stage separation method, comprising: (c1) providing a centrifugal liquid separation device as claimed in claim 2; (c2) injecting the liquid into the sample adding section; (c3) driving the body to rotate at a speed such that the liquid can retain the lower density portion in the first density section, the temporary storage section, the first flow channel and the second flow channel by centrifugal force to form a first separation of liquid, and the other portions enter the second density section; (c4) reducing the rotation speed until the body stops rotating, so that the first separation liquid wets the second flow channel through capillary phenomenon; (c5) restarting and increasing the rotation speed to a speed threshold, so that the less dense portion of the first separated liquid rises and enters a second storage section through the second flow channel to form a second separated liquid; (c6) adjusting the body to switch the direction of rotation once, multiple times or continuously until the remaining portion of the first separation liquid with a lower density oscillates and climbs through the first bending portion; (c7) adjusting the body to switch the direction of rotation once, multiple times or continuously, so that the remaining portion of the first separation liquid with a lower density climbs up through the first bending portion through vibration; and (c8) The speed is increased again to a value greater than the speed threshold, so that the remaining portion of the first separation liquid with a lower density passes through the first flow channel into a first storage section to form a third separation liquid.

9. The centrifugal liquid multi-stage separation method according to claim 8, wherein: In step (c1), the inner surface of the second flow channel is subjected to a surface hydrophilic treatment.

10. A centrifugal liquid multi-stage separation method, comprising: (d1) providing a centrifugal liquid separation device as claimed in claim 4; (d2) injecting the liquid into the sample adding section; (d3) driving the body to rotate at a speed such that the liquid can retain the lower density portion in the first density section, the temporary storage section, the first flow channel and the second flow channel by centrifugal force to form a first separation liquid, and the other portions enter the second density section; (d4) switching the direction of the body and reducing the rotation speed to a low speed threshold, so that the portion with lower density in the first separation liquid can climb up and enter the distribution section and the at least one certain amount chamber through the second flow channel to form a second separation liquid, and the other portion enters the at least one waste liquid chamber; (d5) adjusting the rotation speed to a high speed threshold so that the second separation liquid in the at least one certain volume chamber can enter the at least one reaction chamber to perform a reaction; (d6) continuously rotating the body until the first separated liquid remaining in the first density section is further separated by sedimentation according to density; (d7) Switching the direction of the body again allows the lower density portion of the first separation liquid remaining in step (d4) to pass through the first flow channel into a first storage section to form a third separation liquid.

Images