High-flux digital micro-fluidic chip based on PCB
By designing multi-shaped electrodes and reservoir structures on PCB-based digital microfluidic chips, the problem of insufficient chip flux and electrode count is solved, and efficient droplet refinement and high-throughput processing is achieved, suitable for chemistry and experiments in the field of biomedicine.
Patent Information
- Application Number
- CN202421176366.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-27
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2034-05-27
AI Technical Summary
Existing PCB-based digital microfluidic chips have shortcomings in terms of electrode count and flux, and cannot meet the needs of high efficiency and high throughput experiments.
A high-throughput digital microfluidic chip based on PCB is designed, adopting a multi-shaped electrode and reservoir structure, and connecting pin electrodes through wiring to achieve droplet refinement and high-throughput processing.
It effectively increases the flux and electrode count of the chip, and can perform high-throughput fluid material synthesis and detection in the fields of chemistry, biomedicine, etc.
Smart Images
Figure CN222428038U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of digital microfluidics, and in particular relates to a high-throughput digital microfluidics chip based on PCB. Background Art
[0002] The industrial application of digital microfluidics (DMF) technology is currently a hot topic. Although more and more research institutions are working hard to develop digital microfluidics devices that can be used in daily life, commercial products have not been widely used.
[0003] Printed Circuit Board (PCB) is currently used as the substrate of DMF chips and is highly praised by many researchers due to its low cost and easy mass production. As the number of electrodes and control signals on the chip gradually increase during the chip design process, the large number of electrodes gathered together significantly increases the difficulty of connecting the wires between the electrodes. Moreover, the size of traditional electrodes is distributed in an equal-sized array, and the size of the electrodes is too large and the number is too small, which makes it impossible to conduct high-efficiency and high-throughput experiments better and faster.
[0004] Therefore, how to improve the throughput of PCB-based digital microfluidic chips has become an urgent problem to be solved. Utility Model Content
[0005] The utility model provides a high-throughput digital microfluidic chip based on PCB, which effectively improves the flux and the number of electrodes of the digital microfluidic chip based on PCB, and can perform high-throughput fluid material synthesis and detection in the fields of chemistry, biomedicine, etc.
[0006] A high-throughput digital microfluidic chip based on PCB comprises: an upper cover plate, a dielectric hydrophobic layer, a cofferdam and a PCB lower substrate, wherein a driving electrode is arranged on the top layer of the PCB lower substrate, wherein the driving electrode comprises a liquid reservoir and a multi-shaped electrode connected to the liquid reservoir, wherein the driving electrode is connected to a pin electrode through wiring, and when in use, a sample in the liquid reservoir is refined into droplets of different gradient sizes through the multi-shaped electrode.
[0007] Preferably, the PCB lower substrate is connected to a driving device, the arrangement of the pin electrodes is consistent with the pin arrangement of the driving device, the multi-shape electrode includes a first shape electrode and a second shape electrode, the first shape electrode is used to control the movement of droplets of different gradient sizes, and the second shape electrode is used to split droplets of different gradient sizes.
[0008] Preferably, there are a plurality of the liquid reservoirs in the driving electrode, and the plurality of the liquid reservoirs are directly or indirectly connected to a plurality of the first-shaped electrodes and the second-shaped electrodes respectively.
[0009] Preferably, the multiple liquid reservoirs in the driving electrode are independent of each other.
[0010] Preferably, the liquid storage tank is circular, the first-shaped electrode is sawtooth-shaped, and the second-shaped electrode is crescent-shaped.
[0011] Preferably, the upper cover plate comprises, from top to bottom, a soda-lime glass substrate, a conductive layer and a hydrophobic layer, and the upper cover plate is connected to a ground electrode via a copper sheet for grounding.
[0012] Preferably, the epoxy resin glue surrounds the cavity between the upper cover plate and the dielectric hydrophobic layer to form the cofferdam.
[0013] Preferably, the driving electrode and the pin electrode are arranged symmetrically, and the driving electrode is connected to the pin electrode through a via hole of the PCB lower substrate.
[0014] Preferably, the liquid reservoir, the first shape electrode and the second shape electrode are connected to lead electrodes through wiring.
[0015] Preferably, the dielectric hydrophobic layer is located between the PCB lower substrate and the cofferdam, and the dielectric hydrophobic layer comprises a dielectric layer and a hydrophobic layer.
[0016] The utility model provides a high-throughput digital microfluidic chip based on PCB, including an upper cover plate, a dielectric hydrophobic layer, a cofferdam and a PCB lower substrate, the top layer of the PCB lower substrate is provided with a driving electrode, the driving electrode includes a liquid reservoir and a multi-shaped electrode connected to the liquid reservoir, the driving electrode is connected to the pin electrode through wiring, and when in use, the sample in the liquid reservoir is refined into droplets of different gradient sizes by the multi-shaped electrode. Compared with the prior art, the utility model effectively improves the throughput and the number of electrodes of the digital microfluidic chip based on PCB by refining the sample in the liquid reservoir into droplets of different gradient sizes and then analyzing them, and can perform high-throughput fluid material synthesis and detection in the fields of chemistry, biomedicine, etc.
[0017] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0019] Figure 1 A side schematic diagram of a PCB lower substrate and a dielectric hydrophobic layer provided in one embodiment of the utility model;
[0020] Figure 2 A schematic diagram of a high-throughput digital microfluidic chip electrode pattern based on PCB provided in one embodiment of the utility model;
[0021] Figure 3 A schematic diagram of PCB lower substrate electrode wiring provided in one embodiment of the utility model.
[0022] Description of reference numerals:
[0023] 1. Upper cover; 2. Epoxy resin glue; 3. Droplets; 4. Dielectric hydrophobic layer; 5. PCB lower substrate; 6. Via holes;
[0024] 11. Soda-lime glass substrate; 12. Conductive layer; 13. Hydrophobic layer;
[0025] 511, liquid reservoir; 512, large serrated electrode; 513, large crescent-shaped electrode; 514, small crescent-shaped electrode; 515, small serrated electrode; 516, ground electrode; 517, pin electrode. DETAILED DESCRIPTION
[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0027] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.
[0028] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.
[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0030] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0032] The industrial application of digital microfluidics (DMF) is a research hotspot that scientists are currently paying attention to. Although more and more research institutions are working hard to develop digital microfluidics devices that can be used in daily life, commercial products have not been truly widely used. There are many ways to drive droplets with digital microfluidics. Among them, digital microfluidics based on the principle of electrowetting on the medium is one of the most mature and promising digital microfluidics technologies. It has the advantages of electrical control, reversibility, high operational flexibility and electrical integration LOC (Lead on chip, LOC). It can be widely used in chemistry, medicine, biology and other fields, such as sample preparation, cell culture, polymerase chain reaction (PCR), product detection, single cell analysis, etc.
[0033] In DMF chips, the substrate material determines the chip processing and electrode array design. Glass's excellent chemical inertness makes it the first choice for DMF chip substrates. However, the complex processing and high price make it difficult to promote on a large scale. In addition, the introduction of substrates including paper and polymer flexible materials allows DMF chips to be applied to different needs. The electrodes of DMF chips are generally made of metal or other conductive materials. In recent years, the use of low-cost and easy-to-mass-produce PCBs as substrates for DMF chips has been highly praised by many researchers. This is because the construction of multi-layer PCBs solves the problem of difficult wiring between glass and silicon chip substrate electrodes and external contacts, making the construction of large-scale electrode arrays possible.
[0034] In recent years, in order to improve the efficiency of digital microfluidic chips in processing samples and realize their wide application, the number of electrodes on the chip gradually increases during the chip design process, and the control signal increases accordingly. The large number of electrodes gathers, which significantly increases the difficulty of connecting the wires between the electrodes. At the same time, the size of traditional electrodes is distributed in an equal-sized array, and the size of the electrodes is too large and the number is too small, which makes it impossible to conduct high-efficiency and high-throughput experiments better and faster. This is also one of the important issues that restrict the further development of microfluidic chips.
[0035] Therefore, how to achieve high throughput based on PCB digital microfluidic chips is crucial to the widespread application of digital microfluidic chips.
[0036] Please refer to Figure 1 to Figure 3 , Figure 1 It is a side schematic diagram of a PCB lower substrate and a dielectric hydrophobic layer of the utility model; Figure 2 A schematic diagram of the electrode pattern of a high-throughput digital microfluidic chip based on PCB; Figure 3 A schematic diagram of the electrode wiring on the lower substrate of a PCB.
[0037] The utility model provides a high-throughput digital microfluidic chip based on PCB, comprising: an upper cover plate 1, a dielectric hydrophobic layer 4, a cofferdam and a PCB lower substrate 5, a driving electrode is arranged on the top layer of the PCB lower substrate, the driving electrode comprises a liquid reservoir 511 and a multi-shaped electrode connected to the liquid reservoir 511, the driving electrode is connected to a pin electrode 517 through wiring, when in use, the PCB lower substrate 5 is connected to a driving device for manipulating droplets, the sample in the liquid reservoir 511 is refined into droplets of different gradient sizes by the multi-shaped electrodes, and the arrangement of the pin electrodes 517 is consistent with the pin arrangement of the driving device.
[0038] Specifically, Figure 1 A side schematic diagram of a PCB lower substrate and a dielectric hydrophobic layer provided for one embodiment of the utility model includes: an upper cover plate 1; epoxy resin glue 2; a droplet 3; a dielectric hydrophobic layer 4; a PCB lower substrate 5; and a via 6.
[0039] Exemplarily, the upper cover plate 1 forms a sandwich structure with the epoxy resin glue 2 and the dielectric hydrophobic layer 4 to form a cofferdam, and the height of the cofferdam is 30-200 μm, which is used to provide space for the droplets to move.
[0040] Further, such as Figure 3 As shown, the lower substrate 5 includes a driving electrode and a pin electrode 517. The driving electrode includes a liquid reservoir 511 and a multi-shaped electrode connected to the liquid reservoir 511. The driving electrode is connected to the pin electrode 517 by wiring. When in use, the sample in the liquid reservoir 511 is refined into droplets of different gradient sizes by the multi-shaped electrode. Preferably, the number of driving electrodes in the chip provided by the utility model is 100-150, and multiple droplets can be driven simultaneously. The driving electrode pattern can be a rectangle.
[0041] Furthermore, the surface roughness of the driving electrode Ra is ≤ 5 μm; the gap between adjacent driving electrodes is ≤ 200 μm, and the size of the liquid reservoir 511 is 150-320 mm 2 , can accommodate 5-40μL liquid samples; the driving electrode has a side length of 1-4mm and can drive 0.5-10μL droplets.
[0042] Exemplarily, the multi-shaped electrode includes a first-shaped electrode and a second-shaped electrode, the first-shaped electrode is used to control the movement of droplets of different gradient sizes, and the second-shaped electrode is used to split the droplets of different gradient sizes.
[0043] Exemplarily, there are multiple liquid reservoirs 511 in the driving electrode, and the multiple liquid reservoirs 511 are directly or indirectly connected to the multiple first-shaped electrodes and the second-shaped electrodes; the multiple liquid reservoirs 511 are independent of each other.
[0044] Exemplarily, the liquid reservoir 511 is circular, the first-shaped electrode is sawtooth-shaped, and the second-shaped electrode is crescent-shaped.
[0045] Specifically, Figure 2 There are 4 liquid reservoirs 511, and the 4 liquid reservoirs 511 are independent of each other. The liquid reservoirs 511 are connected to the large serrated electrode 512, and the large serrated electrode 512 is connected to the large crescent-shaped electrode 513. The large serrated electrode 512 controls the droplets in the liquid reservoir 511 to move toward the large crescent-shaped electrode 513. When the droplets pass through the large crescent-shaped electrode 513, they will split into multiple small droplets, and then the small droplets will flow to the small crescent-shaped electrode 514 under the control of the small serrated electrode 515, so as to further refine the small droplets. The small droplets enter the serrated electrode area to react, thereby completing the detection / testing of the sample.
[0046] Specifically, Figure 3As shown, the liquid reservoir (511), the large serrated electrode 512, the large crescent-shaped electrode 513, the small crescent-shaped electrode 514 and the small serrated electrode 515 in the driving electrode are connected to the pin electrode 517 through the via 6 wiring in the lower substrate of the PCB, so that the two can be conductive. Further, the droplets of different gradient sizes refined by the crescent shape enter the serrated electrode area to react, thereby completing the detection / testing of samples of different gradient sizes at the same time.
[0047] For example, Figure 3 As shown, the liquid reservoir 511, the first shape electrode and the second shape electrode are connected to the pin electrode 517 through wiring.
[0048] Specifically, the liquid reservoir 511, the large sawtooth electrode 512, the large crescent electrode 513, the small crescent electrode 514, the small sawtooth electrode 515 and the pin electrode 517 are connected by wiring so that they can be conductive.
[0049] like Figure 2 As shown, the driving electrode and the pin electrode 517 are arranged symmetrically, the liquid reservoir 511 is connected by a serrated electrode 512 with a size of 2mm×2mm and a large crescent-shaped electrode 513 with a size of 2mm×2mm; the large serrated electrode 512 with a size of 2mm×2mm is connected by a small serrated electrode 515 with a size of 1mm×1mm and a small crescent-shaped electrode 514 with a size of 1mm×1mm.
[0050] Furthermore, the driving electrodes may be arranged in M rows and N columns with the same size.
[0051] Exemplarily, the upper cover plate 1 includes from top to bottom: a soda-lime glass substrate 11, a conductive layer 12 and a hydrophobic layer 13. The upper cover plate 1 is grounded to the ground electrode 516 through a copper sheet. The dielectric hydrophobic layer 4 is located between the PCB lower substrate 5 and the cofferdam. The dielectric hydrophobic layer 4 includes a dielectric layer and a hydrophobic layer.
[0052] The conductive layer 12 is prepared on the conductive side surface of the soda-lime glass substrate 11, and then a transparent hydrophobic layer 13 is prepared on the surface, so that the upper cover plate 1 is prepared;
[0053] Specifically, the dielectric hydrophobic layer 4 is located above the PCB lower substrate 5, including a dielectric layer and a hydrophobic layer. The dielectric layer can be made of an ion gel film, a sealing film, polytetrafluoroethylene (PTFE) polydimethylsiloxane or other films that are easy to transfer, with a thickness of 2-20 μm; the hydrophobic layer can be made of PTFE, Hyflon, CYtop, AF1600, with a thickness of 50-200 μm.
[0054] In another implementation, the dielectric hydrophobic layer 4 is provided with an upper silicone oil layer, a sealing film and a lower silicone oil layer from top to bottom; 15-20 μL of silicone oil is dropped on the surface of the driving electrode area, and the silicone oil evenly covers the driving electrode; the sealing film is evenly pulled to a thickness of 10-15 μm, and then covered on top of the lower silicone oil layer; 15-20 μL of silicone oil is dropped on top of the sealing film, and the silicone oil evenly covers the area where the driving electrode is located, thereby completing the preparation of the dielectric hydrophobic layer.
[0055] The technical solution provided by the utility model proposes a high-throughput digital microfluidic chip based on PCB, including: a PCB lower substrate, a dielectric hydrophobic layer, a cofferdam and an upper cover plate; the PCB lower substrate has 100-150 driving electrodes, and the electrodes have rectangular, sawtooth and crescent shapes, etc., which can drive multiple droplets at the same time and split large droplets into small droplets, thereby achieving high throughput of droplets, and the distance between adjacent driving electrodes is ≤200μm, so that droplets can move between electrodes; the dielectric hydrophobic layer provides a smooth contact surface for droplet movement, reduces the resistance to droplet movement, and reduces the adsorption and residue of droplets on the chip surface during movement; the upper cover plate forms a sandwich structure with the dielectric hydrophobic layer through epoxy resin glue, and the cofferdam height is 30-200μm. The utility model can produce droplets of different sizes, which is suitable for manipulating fluid materials of different types and volumes, and can perform high-throughput fluid material synthesis and detection in the fields of chemistry, biomedicine, etc.
[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.
Claims
1. A high-throughput digital microfluidic chip based on PCB, comprising: An upper cover plate (1), a dielectric hydrophobic layer (4), a cofferdam and a PCB lower substrate (5), characterized in that a driving electrode is arranged on the top layer of the PCB lower substrate (5), the driving electrode comprises a liquid reservoir (511) and a multi-shaped electrode connected to the liquid reservoir (511), the driving electrode is connected to a pin electrode (517) via wiring, and the sample in the liquid reservoir (511) is refined into droplets of different gradient sizes by the multi-shaped electrode.
2. The high-throughput digital microfluidic chip based on PCB according to claim 1, characterized in that: The PCB lower substrate (5) is connected to a driving device, the arrangement of the pin electrodes (517) is consistent with the pin arrangement of the driving device, the multi-shaped electrodes include a first-shaped electrode and a second-shaped electrode, the first-shaped electrode is used to control the movement of droplets of different gradient sizes, and the second-shaped electrode is used to split the droplets of different gradient sizes.
3. The PCB-based high-throughput digital microfluidic chip according to claim 2, characterized in that: There are a plurality of liquid reservoirs (511) in the driving electrode, and the plurality of liquid reservoirs (511) are directly or indirectly connected to a plurality of the first-shaped electrodes and the second-shaped electrodes, respectively.
4. The PCB-based high-throughput digital microfluidic chip according to claim 3, characterized in that: The multiple liquid storage tanks (511) in the driving electrode are independent of each other.
5. The PCB-based high-throughput digital microfluidic chip according to claim 2, characterized in that: The liquid storage tank (511) is circular, the first-shaped electrode is sawtooth-shaped, and the second-shaped electrode is crescent-shaped.
6. The PCB-based high-throughput digital microfluidic chip according to claim 1, characterized in that: The upper cover plate (1) comprises, from top to bottom, a soda-lime glass substrate (11), a conductive layer (12) and a hydrophobic layer (13); the upper cover plate (1) is connected to the ground electrode (516) via a copper sheet and is grounded.
7. The PCB-based high-throughput digital microfluidic chip according to claim 1, characterized in that: The epoxy resin glue (2) surrounds the upper cover plate (1) and the dielectric hydrophobic layer (4) to form a cavity, thereby forming the cofferdam.
8. The PCB-based high-throughput digital microfluidic chip according to claim 1, characterized in that: The driving electrode and the pin electrode (517) are arranged symmetrically, and the driving electrode is connected to the pin electrode (517) through a via hole (6) of the PCB lower substrate (5).
9. The PCB-based high-throughput digital microfluidic chip according to claim 2, characterized in that: The liquid reservoir (511), the first shape electrode and the second shape electrode are connected to the lead electrode (517) through wiring.
10. The PCB-based high-throughput digital microfluidic chip according to claim 1, characterized in that: The dielectric hydrophobic layer (4) is located between the PCB lower substrate (5) and the cofferdam, and the dielectric hydrophobic layer (4) comprises a dielectric layer and a hydrophobic layer.