Microfluidic chip and liquid manipulation method

Abstract

This application relates to the field of liquid manipulation, disclosing a microfluidic chip and a liquid manipulation method, including a first electrode plate and a second electrode plate, with a liquid flow channel formed between the first and second electrode plates. The liquid flow channel includes a storage region, a distribution region, and a connecting region, with the connecting region located between the storage region and the distribution region. The height of the storage region is greater than the height of the distribution region. The first electrode plate includes an electrode layer, and the second electrode plate includes a driving electrode layer. The driving electrode layer includes a first electrode, a second electrode, and a third electrode, corresponding sequentially to the storage region, the connecting region, and the distribution region. The third electrode includes sub-electrodes arranged in an array, with at least two rows and two columns of sub-electrodes. The two-stage structural design effectively reduces costs; the mother liquor can be separated into sub-droplets in a single step, eliminating the need for intermediate droplet transitions, resulting in good stability and short distribution manipulation time. The third electrode includes multiple sub-electrodes, making it easier for the mother liquor to enter the distribution region and break apart to form sub-droplets, and allowing for flexible control of the sub-droplet volume.

Description

Technical Field

[0001] This application relates to the field of liquid manipulation, and in particular to a microfluidic chip and a liquid manipulation method. Background Technology

[0002] In technologies such as large-scale chemical and biological synthesis, multi-sample processing, or multi-target detection, it is often necessary to separate multiple sub-droplets from a large volume of mother liquor for parallel processing. Microfluidic chips based on dielectric wetting technology can realize the separation and manipulation of droplets.

[0003] Current microfluidic chips consist of three regions: a liquid storage region, a droplet metering region, and a droplet distribution region. The height of these three regions decreases sequentially, employing a three-tiered structure design. Furthermore, the driving electrodes are irregularly arranged. The small electrodes in the droplet distribution region are partially surrounded by the specially shaped large electrodes in the droplet metering region, requiring overlapping portions between the lateral and vertical electrodes to facilitate droplet movement. During liquid separation, the liquid enters the liquid storage region. The mother liquor in the liquid storage region first undergoes a separation process in the droplet metering region, separating an intermediate droplet. This intermediate droplet then enters the droplet distribution region, where a second separation process separates the desired sub-droplets. This two-stage separation process results in a relatively long time to acquire sub-droplets and instability of the intermediate droplets. Moreover, different liquid volumes require different spatial heights and electrode sizes in the distribution region, leading to poor separation flexibility. Simultaneously, this three-tiered chip design and the design of the driving electrodes result in high fabrication difficulty, high precision, and high manufacturing costs for microfluidic chips.

[0004] Therefore, how to solve the above-mentioned technical problems should be a key focus for those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a microfluidic chip and a liquid manipulation method to simplify the structure, reduce manufacturing costs, shorten the liquid separation and manipulation time, improve stability, and flexibly adjust the size of sub-droplets.

[0006] To solve the above-mentioned technical problems, this application provides a microfluidic chip, including a first electrode plate and a second electrode plate disposed opposite to each other, with a liquid flow channel formed between the first electrode plate and the second electrode plate;

[0007] The liquid flow channel includes a liquid storage area, a liquid distribution area, and a connecting area. The connecting area is located between the liquid storage area and the liquid distribution area, and the height of the liquid storage area is greater than the height of the liquid distribution area.

[0008] The first electrode plate includes an electrode layer, and the second electrode plate includes a driving electrode layer. The driving electrode layer includes a first electrode, a second electrode, and a third electrode that correspond sequentially to the liquid storage area, the connection area, and the liquid distribution area. The third electrode includes sub-electrodes arranged in an array, and the number of rows and columns of the sub-electrodes is at least 2.

[0009] Optionally, the first electrode plate further includes a dielectric hydrophobic layer located on the surface of the electrode layer opposite to the second electrode plate.

[0010] Optionally, the first electrode plate further includes a first substrate located on the surface of the electrode layer away from the second electrode plate.

[0011] Optionally, the second electrode plate further includes a dielectric layer and a second substrate stacked in a direction away from the first electrode plate, with the driving electrode layer embedded between the dielectric layer and the second substrate.

[0012] Optionally, the second electrode plate further includes a hydrophobic layer located on the surface of the dielectric layer opposite to the first electrode plate.

[0013] Optionally, the ratio of the height of the liquid storage area to the height of the liquid distribution area is in the range of 10:1 to 1:1.

[0014] Optionally, the ramp angle of the connecting area is greater than 0° and less than or equal to 90°.

[0015] Optionally, the surface of the second electrode plate opposite to the first electrode plate is a flat surface, and the surface of the first electrode plate opposite to the second electrode plate is a stepped surface.

[0016] Optionally, at least one of the sub-electrodes comprises at least two electrode units.

[0017] This application also provides a liquid manipulation method, which is based on any of the microfluidic chips described above, and includes:

[0018] Activate the first electrode to bring the mother liquor in the storage area closer to the connection area;

[0019] Activate the second electrode to extend the mother liquor from the storage area to the connection area;

[0020] The third electrode is activated sequentially, causing the mother liquor tip to first partially enter the separation zone and then extend within the separation zone; the mother liquor tip is the end of the mother liquor closest to the separation zone.

[0021] After the mother liquor has extended in the separation zone, the activated target third electrode is turned off, causing the mother liquor to break apart and split into sub-droplets.

[0022] This application provides a microfluidic chip including a first electrode plate and a second electrode plate disposed opposite to each other, with a liquid flow channel formed between the first electrode plate and the second electrode plate; the liquid flow channel includes a liquid storage region, a liquid distribution region, and a connecting region, the connecting region being located between the liquid storage region and the liquid distribution region, and the height of the liquid storage region being greater than the height of the liquid distribution region; the first electrode plate includes an electrode layer, the second electrode plate includes a driving electrode layer, the driving electrode layer including a first electrode, a second electrode, and a third electrode corresponding sequentially to the liquid storage region, the connecting region, and the liquid distribution region, the third electrode including sub-electrodes arranged in an array, the number of rows and columns of the sub-electrodes being at least 2.

[0023] As can be seen, the microfluidic chip in this application includes a storage region and a distribution region of different heights, employing a two-stage structural design. This design is simple and can significantly reduce the manufacturing difficulty of the cartridge, effectively lowering costs. During distribution, the mother liquor from the storage region enters the distribution region, and the mother liquor is separated into sub-droplets in a single step, eliminating the need for intermediate droplets. This results in good stability and short distribution control time. Furthermore, the third electrode corresponding to the distribution region in this application includes an array of sub-electrodes. The number of rows of sub-electrodes is at least two, making it easier for the mother liquor to enter the distribution region during separation. The number of columns of sub-electrodes is at least two, which not only facilitates the separation of the mother liquor into sub-droplets but also allows for the activation of different sub-electrodes to obtain sub-droplets of the desired size, enabling flexible control of the sub-droplet volume.

[0024] In addition, this application also provides a droplet manipulation method with the above advantages. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This application provides a schematic diagram of the structure of a microfluidic chip. Figure 1 ;

[0027] Figures 2 to 4 This is a schematic diagram of different driving electrodes provided in the embodiments of this application;

[0028] Figure 5 This application provides a schematic diagram of the structure of a microfluidic chip. Figure 2 ;

[0029] Figures 6 to 7 This is a schematic diagram of different driving electrodes provided in the embodiments of this application;

[0030] Figures 8 to 11 These are timing diagrams of different droplet separation provided in the embodiments of this application;

[0031] In the figure, 1 is the first electrode plate, 2 is the second electrode plate, 3 is the liquid flow channel, 4 is the injection port, 11 is the first substrate, 12 is the electrode layer, 13 is the dielectric hydrophobic layer, 21 is the second substrate, 22 is the driving electrode layer, 23 is the dielectric layer, 24 is the hydrophobic layer, 221 is the first electrode, 222 is the second electrode, 223 is the third electrode, 2231 is the sub-electrode, 22311 is the electrode unit, 31 is the liquid storage area, 33 is the liquid distribution area, and 32 is the connection area. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0034] Dielectric wetting is a novel driving method for electrically controlled surface tension in microfluidics. It involves applying voltage to a microelectrode embedded under a dielectric layer to change the wetting characteristics between the dielectric layer and the conductive droplets attached to its surface. This changes the liquid-solid contact angle, causing asymmetrical deformation at both ends of the droplet and generating a pressure difference inside the droplet, thereby enabling the manipulation and control of droplet deformation or movement.

[0035] As described in the background section, current microfluidic chips employ a three-tiered structure design and have complex driving electrode designs, resulting in high fabrication difficulty, high precision requirements, and high manufacturing costs. Furthermore, the separation of the mother liquor requires the use of intermediate droplets for transition, leading to poor stability and long processing time.

[0036] In view of this, this application provides a microfluidic chip, please refer to... Figure 1 ,include:

[0037] A first electrode 1 and a second electrode 2 are arranged opposite to each other, and a liquid flow channel 3 is formed between the first electrode 1 and the second electrode 2.

[0038] The liquid flow channel 3 includes a liquid storage area 31, a liquid distribution area 33, and a connecting area 32. The connecting area 32 is located between the liquid storage area 31 and the liquid distribution area 33. The height of the liquid storage area 31 is greater than the height of the liquid distribution area 33.

[0039] The first electrode plate 1 includes an electrode layer 12, and the second electrode plate 2 includes a driving electrode layer 22. The driving electrode layer 22 includes a first electrode 221, a second electrode 222, and a third electrode 223 that correspond sequentially to the liquid storage area 31, the connection area 32, and the liquid distribution area 33. The third electrode 223 includes sub-electrodes 2231 arranged in an array, and the number of rows and columns of the sub-electrodes 2231 is at least 2.

[0040] When manipulating the liquid, a voltage is applied between the first electrode 1 and the second electrode 2.

[0041] The electrode layer 12 is distributed in the liquid storage area 31, the liquid distribution area 33 and the connecting area 32.

[0042] The microfluidic chip is also provided with a liquid injection port 4 for injecting liquid into the liquid storage area 31. The liquid injection port 4 can be located on the first electrode plate 1 or in other locations, which is not limited in this application.

[0043] The electrode layer 12 can be a film layer formed by coating with a conductive material. Its main purpose is to connect to the ground or working ground and remove the induced charge generated by the first electrode 1 when the droplet is driven by AC current. The material of the electrode layer 12 can be ITO (indium tin oxide), silver nanowires, conductive ink, PEDOT (polymer of 3,4-ethylenedioxythiophene monomer), etc.

[0044] The first electrode 221 corresponds to the liquid storage area 31, the second electrode 222 corresponds to the connection area 32, and the third electrode 223 corresponds to the liquid separation area 33.

[0045] The main function of the first electrode 221 is to move the large volume of mother liquor in the storage area 31 to the vicinity of the separation area 33, so as to facilitate the subsequent separation operation.

[0046] It should be noted that the first electrode 221 is not limited in this application and can be defined as appropriate. For example, the first electrode 221 can be a single electrode or include multiple electrodes, wherein the multiple electrodes can be distributed in an array, and the number of rows and columns of the array formed by the multiple electrodes are integers greater than or equal to 1. The shape of the first electrode 221 includes, but is not limited to, rectangles and squares.

[0047] It should also be noted that the second electrode 222 is not limited in this application and can be set as needed. For example, the second electrode 222 can be a single electrode or include multiple electrodes, wherein the multiple electrodes can be distributed in an array, and the number of rows and columns of the array formed by the multiple electrodes are integers greater than or equal to 1. The shape of the second electrode 222 includes, but is not limited to, rectangle and square.

[0048] The function of the third electrode 223 is to introduce the mother liquor into the sub-region and separate the mother liquor to obtain sub-droplets.

[0049] The number of rows and columns of sub-electrodes 2231 in the third electrode 223 are both integers greater than or equal to 2. For example, the number of rows of sub-electrodes 2231 can be 2, 3, 4, 5, 6, etc., and the number of columns of sub-electrodes 2231 can be 2, 3, 4, 5, 6, etc. The specific number of rows and columns can be set according to the usage scenario and the required amount of reagents.

[0050] In one possible implementation, the number of rows and columns of the sub-electrode 2231 are equal. However, this application does not specifically limit this; in another possible implementation, the number of rows and columns of the sub-electrode 2231 are not equal.

[0051] The purpose of setting the number of rows of sub-electrodes 2231 to at least 2 is to make it easier for the mother liquor to enter the separation zone 33 when separating the mother liquor. The purpose of setting the number of columns of sub-electrodes 2231 to at least 2 is to make it easier for the mother liquor to break into sub-droplets when separating the mother liquor. Moreover, by activating different sub-electrodes 2231, the desired size of sub-droplets can be obtained, and the volume of the sub-droplets can be flexibly controlled.

[0052] As one possible implementation, each sub-electrode 2231 can be an integral electrode, and different arrangements of the driving electrode layer 22 are as follows: Figures 2 to 4 As shown, the sub-electrodes 2231 in the third electrode 223 are distributed in 3 rows × 3 columns, 3 rows × 5 columns, and 2 rows × 5 columns, respectively.

[0053] The height h1 of the liquid storage area 31 is greater than the height h2 of the liquid distribution area 33, forming two different spatial heights, thus making the microfluidic chip in this application a second-order liquid distribution structure.

[0054] As one possible implementation, the ratio of the height h1 of the storage zone 31 to the height h2 of the separation zone 33 ranges from 10:1 to 1:1. The larger the ratio of h1 to h2, the larger the height h1 of the storage zone 31. Theoretically, with the same area, the storage zone 31 can store a larger volume of liquid, serving as a storage chamber for the reaction reagents before the reaction begins, storing more reagents. However, at the same time, the resistance of droplets entering the separation zone 33 from the storage zone 31 is also greater, which may prevent liquid from entering the separation zone 33, ultimately leading to separation failure. The smaller the ratio of h1 to h2, the smaller the resistance of droplets entering the separation zone 33 from the storage zone 31, which may result in the actual volume of the separated droplets being larger than the theoretically designed volume, causing insufficient separation accuracy. Therefore, the ratio of h1 to h2 is set between 10:1 and 1:1. For example, the ratio can be 10:1, 9:1, 8:1, 5:1, 4:1, 3:1, 2:1, 1.5:1, etc.

[0055] Preferably, the ratio of the height h1 of the storage zone 31 to the height h2 of the distribution zone 33 is in the range of 4:1 to 2:1 to obtain a better distribution effect. The distribution effect is best when the ratio of the height h1 of the storage zone 31 to the height h2 of the distribution zone 33 is 3:1 or around 3:1.

[0056] In one embodiment of the application, the first electrode plate 1 may further include a first substrate 11, which is located on the surface of the electrode layer 12 away from the second electrode plate 2. The first substrate 11 may serve as a support structure for the first electrode plate 1.

[0057] The first electrode plate 1 may further include a dielectric hydrophobic layer 13, which is located on the surface of the electrode layer 12 opposite to the second electrode plate 2. The dielectric hydrophobic layer 13 has both hydrophobic and dielectric properties. Alternatively, the first electrode plate 1 may have a two-layer structure consisting of a dielectric layer and a hydrophobic layer, the functions of which are the same as those of a single-layer dielectric hydrophobic layer 13. The purpose of hydrophobicity is to ensure that the first substrate 11 is not wetted by the liquid to be driven, thereby improving droplet control.

[0058] In one possible implementation, the second electrode 2 further includes a dielectric layer 23 and a second substrate 21 stacked in a direction away from the first electrode 1, with the driving electrode layer 22 embedded between the dielectric layer 23 and the second substrate 21. The second substrate 21 can serve as a support structure for the second electrode 2.

[0059] The dielectric layer 23 refers to a film layer formed by coating with a dielectric material. The dielectric material is an insulator, but it can be polarized under the action of an external electric field, transmitting, storing, or recording the effect of the electric field through induction rather than conduction. The materials of the dielectric layer 23 include, but are not limited to, polymers such as polystyrene, polyimide, polycarbonate, and parylene.

[0060] The microfluidic chip in this embodiment includes a liquid storage region 31 and a liquid distribution region 33 with different heights. It adopts a two-stage structure design, which is simple and can significantly reduce the manufacturing difficulty of the cartridge, effectively lowering costs. During liquid distribution, the mother liquor in the storage region 31 enters the liquid distribution region 33. The mother liquor is separated into sub-droplets in one step, without the need for intermediate droplets, resulting in good stability and short distribution control time. Furthermore, the third electrode 223 corresponding to the liquid distribution region 33 in this application includes an array of sub-electrodes 2231. The number of rows of sub-electrodes 2231 is at least two, which makes it easier for the mother liquor to enter the liquid distribution region 33 during separation. The number of columns of sub-electrodes 2231 is at least two, which not only makes it easier for the mother liquor to break apart and form sub-droplets during separation, but also allows for the activation of different sub-electrodes 2231 to obtain sub-droplets of the desired size, enabling flexible control of the sub-droplet volume.

[0061] like Figure 5 As shown, based on any of the above embodiments, in one embodiment of this application, in the microfluidic chip, the second electrode 2 may further include a hydrophobic layer 24, the hydrophobic layer 24 being located on the surface of the dielectric layer 23 opposite to the first electrode 1.

[0062] The hydrophobic layer 24 can be a film layer formed by coating with a hydrophobic material. Its main purpose is to ensure that the second substrate 21 is not wetted by the liquid to be driven when no electricity is applied, so as to better control the droplets. The material of the hydrophobic layer 24 can be a fluorinated polymer material, such as polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP).

[0063] Because the storage area 31 and the distribution area 33 are at different heights, the connecting area 32 will have a slope at a certain angle. As one possible implementation method, such as... Figure 1 As shown, the surface of the second electrode plate 2 opposite to the first electrode plate 1 is a flat surface, and the surface of the first electrode plate 1 opposite to the second electrode plate 2 is a stepped surface.

[0064] The slope of the connecting area 32 is located at the step formed by the first electrode plate 1, and the slope angle is the angle between the slope and the flat surface of the second electrode plate 2.

[0065] As another possible implementation, the surfaces of the first electrode plate 1 and the second electrode plate 2 facing each other are flat surfaces, and the surfaces of the second electrode plate 2 and the first electrode plate 1 facing each other are stepped surfaces.

[0066] Based on any of the above embodiments, in one embodiment of this application, the ramp angle of the connection area 32 is greater than 0° and less than or equal to 90°.

[0067] Because the storage area 31 and the distribution area 33 are at different heights, the connecting area 32 will have a certain angle of slope. When the slope angle α is equal to 90°, that is, the connecting area 32 does not exist, and the storage area 31 and the distribution area 33 are directly connected.

[0068] To achieve optimal liquid separation, preferably, as an implementation method, the slope angle α is greater than or equal to 30° and less than or equal to 60°. Within a certain range, the larger the slope angle α, the smaller the resistance of the liquid entering the separation zone 33 from the storage zone 31. However, if the slope angle α is too large, the actual volume of the separated droplets may be larger than the theoretically designed volume, resulting in insufficient separation accuracy. Within a certain range, the smaller the slope angle α, the greater the resistance of the droplets entering the separation zone 33 from the storage zone 31, which may prevent the droplets from entering the separation zone 33, ultimately leading to separation failure. This is because the smaller the slope angle α, the larger the contact area between the droplets and the connecting zone 32. Since the surface of the connecting zone 32 is hydrophobic, the resistance is also greater.

[0069] The separation effect is optimal when the slope angle α is equal to or around 30°.

[0070] With driving electrode layer 22 as Figure 8 Taking the example shown, the slope angle and the ratio of the height h1 of the liquid storage area 31 to the height h2 of the liquid distribution area 33 are verified.

[0071] The verification results of continuous 8-drop dispensing at different height ratios when the slope angle of the connecting zone 32 is fixed (α = 45°), and the verification results of continuous 8-drop dispensing at different α angles when the height ratio is fixed at 3:1 (i.e., h1 is 1.8 mm and h2 is 0.6 mm), are shown in Table 1. The units for mother liquor volume and target volume are μL. "×" indicates a risk of dispensing failure. The CV value represents the repeatability of the 8-drop volume, and the deviation is the difference between the mean and the target volume.

[0072] The area of ​​a single sub-electrode is 2.6mm × 2.6mm, and the gap between two sub-electrodes is 0.11mm.

[0073] Table 1

[0074]

[0075] Based on any of the above embodiments, in one embodiment of this application, at least one of the sub-electrodes 2231 includes at least two electrode units 22311.

[0076] It should be noted that, in the sub-electrodes 2231 of the third electrode 223, some sub-electrodes 2231 may include at least two electrode units 22311, or all sub-electrodes 2231 may be configured to include at least two electrode units 22311.

[0077] By dividing the sub-electrode 2231 into at least two electrode units 22311, the electrode units 22311 can be activated individually when manipulating the liquid, thereby allowing for more flexible control of the sub-droplet volume.

[0078] The number of electrode units 22311 included in a sub-electrode 2231 is not specifically limited in this application, but depends on the circumstances. For example, the number of electrode units 22311 included in a sub-electrode 2231 can be two, three, four, five, etc.

[0079] The shape of the electrode unit 22311 includes, but is not limited to, square, rectangle, triangle, and trapezoid. The size of each electrode unit 22311 is not limited in this application and can be set according to actual needs.

[0080] For example, when the number of electrode units 22311 in a sub-electrode 2231 is three and the shape is rectangular, the schematic diagram of the sub-electrode 2231 is as follows. Figure 7 As shown, when the number of electrode units 22311 in a sub-electrode 2231 is four and the shape is triangular, the schematic diagram of the sub-electrode 2231 is as follows. Figure 6 As shown.

[0081] This application also provides a liquid manipulation method, which is based on the microfluidic chip described in any of the above embodiments, and includes:

[0082] Step S101: Activate the first electrode to bring the mother liquor in the storage area closer to the connection area.

[0083] Step S102: Activate the second electrode to extend the mother liquor from the storage area to the connection area.

[0084] Step S103: Sequentially activate the third electrode so that the front end of the mother liquor first partially enters the separation zone and then extends in the separation zone; the front end of the mother liquor is the end of the mother liquor closest to the separation zone.

[0085] When activating the third electrode sequentially, the first column of sub-electrodes needs to be activated first to pull the mother liquor droplets toward the separation zone, and then the sub-electrodes after the first column are activated. During activation, the mother liquor is first pulled backward and then extended to both sides to achieve the extension of the mother liquor in the separation zone.

[0086] Step S104: After the mother liquor has extended in the separation zone, the activated target third electrode is turned off, causing the mother liquor to break and split into sub-droplets.

[0087] It should be noted that when the sub-electrode includes an electrode unit, the electrode unit can be activated or deactivated according to the required sub-droplet size to control the mother liquor.

[0088] The separation process using several different driving electrodes will be described below. Figures 8 to 11 The white sub-electrode represents an inactive (no voltage applied) electrode, while the patterned sub-electrode represents an active (voltage applied) electrode. After adding the droplet, the droplet is first moved from the storage area to the corresponding third electrode in the distribution area (this process is not shown).

[0089] The first type

[0090] Please refer to Figure 8 The activation status at the third electrode is as follows: Figure 8 As shown in Figures A to H, the sub-electrodes are distributed in a three-row × three-column configuration. In step A, the first column of sub-electrodes is activated to pull the droplet towards the separation zone. In step B, the middle sub-electrode of the second row is activated to ensure that the droplet can enter the separation zone from a higher position in the storage area. Then, in step C, the sub-electrodes of the first row, second column, and third row, second column are activated to extend the droplet. To ensure separation stability, the droplet follows this pattern in its subsequent movement. In step D, the sub-electrodes activated in step C are turned off, and the sub-electrodes of the second row and third column are activated, making it easier for the droplet to move to the right. In step E, the sub-electrodes of the first row, second column, and third row, second column are activated again to allow the droplet to continue moving towards the separation zone. In step F, the sub-electrodes of the first row, first column, and third row, first column are turned off, and the sub-electrodes of the first row, third column, and third row, third column are activated to prevent the volume of liquid entering the separation zone from being too large. In step G, the sub-electrodes of the first row, second column, and third row, second column are turned off. In step H, the sub-electrodes of the second row, second column are turned off to complete the separation of the sub-droplets. The size of the sub-droplet is equal to the volume of three sub-electrodes.

[0091] The second type

[0092] Please refer to Figure 9 The activation status at the third electrode is as follows: Figure 9 As shown in A to K. Figure 9 The principle of neutron droplet separation is the same as described above. Figure 8 The separation principle is similar, and will not be elaborated here. Figure 9 With appendix Figure 8 In comparison, by keeping the number of rows the same but increasing the number of columns to 5, the electrode structure provides more space for droplet propagation and extension, allowing for the separation of larger droplets. Figure 9The example shown is of dividing the liquid into 6 sub-droplets of different sizes. Similarly, the liquid volume can be divided into 9 sub-droplets of different sizes.

[0093] The third type

[0094] Please refer to Figure 10 The activation status at the third electrode is as follows: Figure 10 As shown in A to F, the sub-electrodes are distributed in a two-row × five-column configuration. In A, the sub-electrodes in the first row and first column are activated first. Then, as shown in B, the sub-electrodes in the second row and first column are activated to pull the droplet toward the separation zone. Next, in C, the two sub-electrodes in the second column are activated to extend the droplet. In D, the two sub-electrodes in the third column are activated, and the droplet continues to extend to the right. In E, the sub-electrodes in the first row and first column, and the sub-electrodes in the first row and second column are deactivated. In F, the sub-electrodes in the second row and second column are deactivated to complete the separation of the sub-droplets, resulting in two sub-droplets of liquid volume.

[0095] From the first to the third method, it can be concluded that the amount of sub-droplets separated can be flexibly controlled by adjusting the number of rows and columns and combining them with different separation sequences.

[0096] The fourth type

[0097] Please refer to Figure 11 The activation status at the third electrode is as follows: Figure 11 As shown in A to G, and Figure 8 In contrast, this design involves three separate sub-electrodes, each consisting of three elongated electrode units. This electrode design allows for the production of sub-droplets with more precise liquid volume.

[0098] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0099] The microfluidic chip and liquid manipulation method provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the solution and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A microfluidic chip, characterized in that, It includes a first electrode plate and a second electrode plate that are disposed opposite to each other, and a liquid flow channel is formed between the first electrode plate and the second electrode plate; The liquid flow channel includes a liquid storage area, a liquid distribution area, and a connecting area. The connecting area is located between the liquid storage area and the liquid distribution area, and the height of the liquid storage area is greater than the height of the liquid distribution area. The first electrode plate includes an electrode layer, and the second electrode plate includes a driving electrode layer. The driving electrode layer includes a first electrode, a second electrode, and a third electrode that correspond sequentially to the liquid storage area, the connecting area, and the liquid distribution area. The third electrode includes sub-electrodes arranged in an array, and the number of rows and columns of the sub-electrodes is at least 2. When the third electrode is activated sequentially, it is activated according to the rule of first pulling the mother liquor backward toward the liquid distribution area, and then extending it to both sides. The slope angle of the connecting area is greater than or equal to 30° and less than or equal to 60°.

2. The microfluidic chip as described in claim 1, characterized in that, The first electrode plate further includes a dielectric hydrophobic layer located on the surface of the electrode layer opposite to the second electrode plate.

3. The microfluidic chip as described in claim 1, characterized in that, The first electrode plate further includes a first substrate, which is located on the surface of the electrode layer away from the second electrode plate.

4. The microfluidic chip as described in claim 1, characterized in that, The second electrode also includes a dielectric layer and a second substrate stacked in a direction away from the first electrode, with the driving electrode layer embedded between the dielectric layer and the second substrate.

5. The microfluidic chip as described in claim 4, characterized in that, The second electrode also includes a hydrophobic layer located on the surface of the dielectric layer opposite to the first electrode.

6. The microfluidic chip as described in claim 1, characterized in that, The ratio of the height of the liquid storage area to the height of the liquid distribution area is in the range of 10:1 to 1:

1.

7. The microfluidic chip as described in claim 1, characterized in that, The surface of the second electrode plate opposite to the first electrode plate is a flat surface, while the surface of the first electrode plate opposite to the second electrode plate is a stepped surface.

8. The microfluidic chip according to any one of claims 1 to 7, characterized in that, At least one of the sub-electrodes comprises at least two electrode units.

9. A method for manipulating liquids, characterized in that, The liquid manipulation method is based on the microfluidic chip as described in any one of claims 1 to 8, and includes: Activate the first electrode to bring the mother liquor in the storage area closer to the connection area; Activate the second electrode to extend the mother liquor from the storage area to the connection area; The third electrode is activated sequentially, causing the mother liquor tip to first partially enter the separation zone and then extend there; the mother liquor tip is the end of the mother liquor closest to the separation zone. After the mother liquor has extended in the separation zone, the activated target third electrode is turned off, causing the mother liquor to break apart and split into daughter droplets.

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