A microfluidic chip processing method

Abstract

The present application relates to the technical field of microfluidic chip, and particularly relates to a microfluidic chip manufacturing method, comprising the following steps: S1, providing the following materials: an optical machine, a chip base, a chip pressing plate and a glass sheet; the glass sheet is pressed on the chip base by the chip pressing plate, and a closed molding space is formed between the chip base and the glass sheet; the chip pressing plate is provided with an opening corresponding to the position of the molding space; the chip base is provided with a liquid inlet channel and a liquid outlet channel which are in communication with the molding space; S2, cleaning the glass sheet: cleaning reagent is introduced into the molding space through the liquid inlet channel, and the cleaning reagent flows through the glass sheet to clean the glass sheet; S3, introducing photosensitive resin; S4, solidification molding: the photosensitive resin is solidified and molded by the light of the optical machine to form a fence, and the main flow channel, the branch flow channel and the reaction unit are formed between the fences; the present application has short manufacturing cycle and good versatility.

Description

[0001] Cross-reference of related applications

[0002] This application is a divisional application based on application number 2024101828357, filed on February 19, 2024, entitled "A method for manufacturing a microfluidic chip". Technical Field

[0003] This invention relates to the field of microfluidic chip technology, and more specifically to a microfluidic chip fabrication method. Background Technology

[0004] Microfluidic chips play a crucial role in the development of some of the most cutting-edge technologies in the fields of biology, chemical engineering, and medical testing. Also commonly known as biochips or bioarrays, or protein chips or gene chips, they originated from the combination of DNA hybridization probe technology and semiconductor industry technology. Biochips integrate biochemical analysis processes onto the chip surface based on the principle of specific interactions between biomolecules, enabling high-throughput and rapid detection of DNA, RNA, peptides, proteins, and other biological components. A large number of probe molecules are immobilized on a support and hybridized with fluorescently labeled DNA or other sample molecules (such as proteins, factors, or small molecules). By detecting the hybridization signal intensity of each probe molecule, the quantity and sequence information of the sample molecules can be obtained.

[0005] The existing microfluidic chip manufacturing method generally involves etching ordinary silicon-based chips to form main channels, branch channels, and reaction units, ultimately forming the chip. The drawbacks of this etching method are that, firstly, the manufacturing cycle is relatively long, generally requiring 3-6 months; secondly, the masks used in this etching process are generally fixed masks, and their patterns cannot be changed after manufacturing, resulting in poor versatility, and therefore, further improvement is needed. Summary of the Invention

[0006] In order to solve at least one of the technical problems mentioned in the background art, the present invention aims to provide a microfluidic chip fabrication method.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for manufacturing a microfluidic chip includes the following steps: S1. Provide the following materials: optical engine, chip base, chip pressure plate, and glass slide; the glass slide is pressed onto the chip base by the chip pressure plate, and a closed molding space is formed between the chip base and the glass slide; the chip pressure plate is provided with an opening corresponding to the molding space; the chip base is provided with a liquid inlet channel and a liquid outlet channel communicating with the molding space; S2. Cleaning the glass slide: The cleaning reagent is introduced into the forming space through the liquid inlet channel, and the cleaning reagent flows through the glass slide to clean it; S3. Introduce photosensitive resin: After cleaning, inject photosensitive resin into the molding space through the liquid inlet channel to fill the molding space. S4. Curing and molding: Turn on the optical engine and output the first photomask. The optical engine irradiates the photosensitive resin in the molding space through the first photomask for a period of time. The photosensitive resin irradiated by the optical engine is cured and molded to form a fence. The fence is used to form the main channel, the branch channel and the reaction unit. S5. Cleaning the glass slide: The cleaning reagent is introduced into the forming space through the liquid inlet channel. The cleaning reagent flows through the glass slide to clean it and wash away the residual photosensitive resin in the forming space.

[0008] As an optional embodiment of the present invention, the following steps are further included after step S5: S6. Cure the CPG carrier, the specific steps are as follows: S61. Inject photosensitive resin into the pore-forming space through the liquid inlet channel; S62. Turn on the optical engine and output the second photomask. The second photomask is used in conjunction with the optical engine to irradiate the photosensitive resin to cure and form a step on the outlet side of the reaction unit; the height of the step is lower than the height of the fence. S63. Clean the glass slide by introducing the cleaning reagent into the molding space through the liquid inlet channel to rinse away the photosensitive resin remaining in the molding space. S64, CPG carrier: The CPG mixture is introduced into the molding space through the liquid inlet channel, so that the CPG mixture enters the reaction unit; S65. Photosensitive resin is introduced into the molding space through the liquid inlet channel, so that it enters the reaction unit; S66. Turn on the optical engine and output the third photomask. The third photomask is used in conjunction with the optical engine to irradiate the photosensitive resin loading carrier CPG in the reaction unit to solidify and form a mold. S67. Clean the glass slide by introducing the cleaning reagent into the molding space through the liquid inlet channel to rinse away the photosensitive resin and carrier CPG remaining in the molding space, thus completing the curing of the carrier CPG.

[0009] As an optional embodiment of the present invention, in step S1, an annular sealing ring is also provided, which is pressed between the chip base and the chip platen, thereby forming the molding space between the chip base and the chip platen.

[0010] As an optional embodiment of the present invention, in step S65, the photosensitive resin introduced is a photosensitive resin that is not resistant to acetonitrile.

[0011] As an optional embodiment of the present invention, the height of the step is greater than 1 CPG and less than 5 μm.

[0012] As an optional embodiment of the present invention, in step S66, the photosensitive resin is cured and molded into a horizontal sheet, a vertical sheet, or a grid pattern.

[0013] As an optional embodiment of the present invention, in step S66, the photosensitive resin is cured into a multi-layered transverse sheet, including the following steps: the photosensitive resin and the carrier CPG are cured to form a cured bottom layer through steps S65 and S66; then steps S65 and S66 are repeated to sequentially stack and cure on the cured bottom layer.

[0014] As an optional embodiment of the present invention, the carrier CPG is at least one of microporous glass beads and microporous magnetic beads.

[0015] Compared with the prior art, the advantages of the present invention are: First, this solution relies on photosensitive resin in conjunction with photomechanical irradiation to solidify and form the main channel, branch channels, and reaction units. The process cycle is basically 0.1-0.3 hours, which is significantly reduced compared to the traditional etching method for chip processing (which has a manufacturing cycle of 3-6 months).

[0016] Secondly, this solution uses a photopolymerization process and employs a digital photomask. Users can modify the pattern on the mask as needed, thus allowing for the customization of microfluidic chips with the required throughput according to user needs. Compared to the fixed masks used in traditional etching processes, this solution offers better versatility.

[0017] Furthermore, this invention further incorporates a CPG carrier into the reaction unit of the manufactured chip. Because the CPG carrier has a porous structure, it offers superior flow performance. In conventional microfluidic chips, reagents flow on the chip carrier plane, while reagents close to the carrier surface remain stationary. Many immobilized oligonucleotides and DNA molecules are very small, residing primarily within the space near the carrier surface, resulting in insufficient reagent exchange. This inadequate exchange contributes to the chip's low reaction efficiency and lack of sensitivity. The chip carrier of this invention is a CPG controllable microporous glass bead. With reactants within the pores, reagent exchange through the micropores is more thorough, leading to higher reaction efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 This is an exploded view of the present invention; Figure 4This is a schematic diagram of the chip base structure; Figure 5 for Figure 4 A magnified view of a portion of the image; Figure 6 for Figure 5 Enlarged view of part A in the middle. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0020] In the following description, terms such as “inner,” “outer,” “upper,” “lower,” “left,” and “right” that indicate orientation or positional relationship are used only for the convenience of describing the embodiments and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0021] Example 1 Please see Figure 1-6 As shown, this embodiment provides a microfluidic chip manufacturing method, which includes the following steps: S1. Provide the following materials: optical engine 7, chip base 1, chip pressure plate 2, glass slide 3, and annular sealing ring 4; the optical engine 7 can be a DLP optical engine, preferably a desktop DLP optical engine, and the wavelength output can be set as needed.

[0022] The glass slide 3 is pressed onto the chip base 1 by the chip pressing plate 2, and a closed molding space 6 is formed between the chip base 1 and the glass slide 3. Specifically, the sealing ring 4 is placed on the top surface of the chip base 1, then the glass slide 3 is pressed onto the sealing ring 4, and finally the chip pressing plate 2 is pressed onto the glass slide 3 and the chip pressing plate 2 is fixed to the chip base 1. At this time, the top surface of the chip base 1, the bottom surface of the glass slide 3, and the inner peripheral wall of the sealing ring 4 together form a closed molding space 6.

[0023] like Figure 1 As shown, the optical engine 7 illuminates from top to bottom. In order for the light to illuminate the molding space 6 area, in this embodiment, the chip plate 2 is provided with an opening corresponding to the molding space 6. In the vertical projection, the opening range of the chip plate 2 is at least larger than the range of the molding space 6.

[0024] like Figure 2As shown, the chip base 1 is provided with an inlet channel 11 and an outlet channel 12 that are connected to the molding space 6. The inlet channel 11 and the outlet channel 12 are located at both ends of the molding space 6. In order to better discharge the reagent or solution, the outlet channel 12 can be provided in two sets, which are referred to as the first outlet channel 121 and the second outlet channel 122 for distinction.

[0025] The liquid inlet channel 11 is mainly used to allow various reagents to enter the molding space 6, while the liquid outlet channel 12 is used to allow reagents to be discharged from the molding space 6.

[0026] In this embodiment, the glass slide 3 can be made of injection-molded transparent PP, PC, or other materials.

[0027] S2. Cleaning the glass slide 3: The cleaning reagent is introduced into the forming space 6 through the inlet channel 11, and then the reagent flows out through the outlet channel 12. This process is repeated 3-5 times. The cleaning reagent flows through the glass slide 3 to clean the glass slide 3 and the forming space 6. This removes some impurities from the forming space 6.

[0028] S3. Introduce photosensitive resin: After cleaning, inject photosensitive resin into the molding space 6 through the liquid inlet channel 11. Excess photosensitive resin flows out from the liquid outlet channel 12 until the photosensitive resin fills the molding space 6.

[0029] S4. Curing and molding: Turn on the optical engine 7 and output the first photomask. It can be understood that the pattern on the first photomask is basically consistent with the pattern of the microfluidic chip to be molded; the photomask refers to the digital photomask.

[0030] The photomechanical system 7 illuminates the photosensitive resin in the molding space 6 through the first photomask for several seconds. The photosensitive resin irradiated by the photomechanical system 7 solidifies and forms the fence 5, while the photosensitive resin in the molding space 6 that is not exposed to light remains in a molten and uncured state; for example... Figure 5 and Figure 6 As shown, the fence 5 encloses and forms a main channel 51, a branch channel 52, and a reaction unit 53. It can be understood that the position and shape of the main channel 51, branch channel 52, and reaction unit 53 enclosed by the fence 5 are determined by the pattern on the first photomask. Users can design the pattern of the first photomask according to their needs, such as... Figure 4-6 The diagram shows the distribution of the main flow channel 51, the branch flow channel 52, and the reaction unit 53. It should be noted that this diagram only shows a partial structure and does not represent the entire chip.

[0031] Step S4 completes the basic fabrication of the microfluidic chip. The next step is to clean the chip. S5. Cleaning the glass slide 3: The cleaning reagent is introduced into the forming space 6 through the liquid inlet channel 11. The cleaning reagent flows through the main channel 51, the branch channel 52, and the reaction unit 53, cleaning the glass slide 3 and the forming space 6 to wash away the residual photosensitive resin in the forming space 6. Specifically, it washes away the uncured photosensitive resin remaining in the main channel 51, the branch channel 52, and the reaction unit 53. This can be repeated 3-5 times.

[0032] As can be seen, this solution relies on photosensitive resin in conjunction with photomechanical 7 to cure and form the main channel 51, branch channel 52, and reaction unit 53. The process cycle is basically 0.1-0.3 hours, which is significantly reduced compared to the traditional etching method for chip processing (which has a manufacturing cycle of 3-6 months).

[0033] Secondly, this solution uses a photopolymerization process and employs a digital photomask. Users can modify the pattern on the mask as needed, thus allowing for the customization of microfluidic chips with the required throughput according to user needs. Compared to the fixed masks used in traditional etching processes, this solution offers better versatility.

[0034] Example 2 This embodiment further processes the microfluidic chip based on Embodiment 1 to load a CPG carrier into the reaction unit 53 of the microfluidic chip. The CPG carrier, specifically controllable microporous glass beads, is a commonly used solid-phase carrier; alternatively, controllable microporous magnetic beads can also be used. CPG with a micropore diameter of 50-300 nm can be selected, and the loading is typically 100 μmol / g to 25 µmol / g, dissolved to form a CPG suspension (i.e., a CPG mixed reagent) for subsequent processing.

[0035] Specifically, the following steps are included after step S5: S6. Cure the CPG carrier, the specific steps are as follows: S61. Inject photosensitive resin into the pore-forming space through the liquid inlet channel 11; so that the photosensitive resin flows into the reaction space along the main channel 51 and the branch channel 52.

[0036] S62. Turn on the optical engine 7 and output the second photomask. This can be understood as follows: Figure 6 As shown, the pattern on the second photomask is adapted to the reaction unit 53 and is used to cooperate with the photomechanical 7 to cure the photosensitive resin on the exit side of the reaction unit 53 to form a step 55. The step 55 here is actually a fence, but it is shorter than the fence 5 of the previous reaction unit 53. That is, the height of the step 55 is lower than the height of the fence 5; preferably, the height of the step 55 is greater than 1 CPG and less than 5 μm, where greater than 1 CPG can be understood as greater than the diameter of one CPG.

[0037] The purpose of forming a barrier 55 on the outlet side of reaction unit 53 is that when CPG mixed reagent is subsequently introduced, the barrier 55 can form a certain blocking effect on the CPG mixed reagent on the outlet side of reaction unit 53, so that a portion of it can be enriched in reaction unit 53 to combine with the subsequent photosensitive resin.

[0038] Conversely, if the step 55 is not set, the CPG will be washed away when the photosensitive resin is introduced later, so that little or no CPG will remain in the reaction unit 53.

[0039] S63. Clean the glass slide 3. Introduce the cleaning reagent into the molding space 6 through the liquid inlet channel 11 to rinse away the photosensitive resin remaining in the molding space 6. This can be repeated 3-5 times.

[0040] S64, CPG carrier: The CPG mixed reagent is introduced into the molding space 6 through the liquid inlet channel 11, and the CPG mixed reagent enters the reaction unit 53 along the main channel 51 and the branch channel 52.

[0041] S65. Photosensitive resin is introduced into the molding space 6 through the liquid inlet channel 11, so that the photosensitive resin enters the reaction unit 53.

[0042] S66. Turn on the optical engine 7 and output the third photomask. The third photomask is mainly used to adapt to the reaction unit 53. The third photomask is used to work with the optical engine 7 to irradiate and solidify the photosensitive resin loading carrier CPG in the reaction unit 53 to form the carrier part 54.

[0043] It is worth noting that in this embodiment, the carrier portion 54 can be fixedly molded in all reaction units 53, such as... Figure 6 As shown, the carrier portion 54 can also be formed by fixing it in only one or some reaction units 53.

[0044] The carrier portion 54, formed by curing the carrier CPG and photosensitive resin together, can be multi-layered transverse sheet-like (e.g. Figure 6 The carrier portion 54 on the left side of the middle section), or multiple rows of vertical sheets (such as... Figure 6 (As shown in the carrier section 54 on the right side of the middle), or in a grid pattern.

[0045] Taking the multi-layered transverse-sheet carrier portion 54 as an example, its generation method is as follows: First, the underlying carrier portion 54 is generated. Specifically, the photosensitive resin and carrier CPG are cured to form a cured underlying layer through steps S65 and S66. Then, steps S65 and S66 are repeated to sequentially stack and cure the cured underlying layer, thus forming a multi-layered transverse carrier portion 54.

[0046] S67. Clean the glass slide 3 by introducing the cleaning reagent into the molding space 6 through the liquid inlet channel 11 to rinse away the photosensitive resin and carrier CPG remaining in the molding space 6, thereby completing the curing of the carrier CPG.

[0047] The microfluidic chip obtained at this time is a chip in which the carrier CPG is loaded in the reaction unit 53. The grafting points of the carrier in traditional microfluidic chips (i.e. biochips) are on the surface of the reaction unit 53 of the chip. Grafting sites are generated by silanization, and the size of the surface area directly determines the unit loading capacity.

[0048] The basic principle of silanization is to utilize the silanol groups formed by the hydrolysis of silicon-oxygen bonds to undergo a dehydration condensation reaction with the silanol groups on the chip surface, thereby coupling functionalized siloxanes on the chip surface as grafting sites for the next reaction.

[0049] Currently, the loading capacity of a planar region with a diameter of 50µm and a height of 15µm in biochip reaction units is generally below 10⁻¹ to 10⁻² fmol. As the loading capacity of biochips increases from 1K to 1000K, the corresponding unit loading capacity decreases further. This low loading capacity severely affects the quantity of oligonucleotides, cDNA, genomic DNA, peptides, antibodies, and antigens immobilized on the biochip, significantly reducing the detection range and reliability. This is especially true for chips used in synthesis, detection, and other fields, where high unit carrier concentrations are required.

[0050] The CPG-loaded chip provided by this invention has a higher loading capacity. The loading capacity of the reaction unit 53 of the chip is >10¹ to 10³ times that of silanized chips of the same area. For example, the reaction unit 53 has a diameter of 50µm and a height of 15µm, a CPG loading capacity of 50µmol / g, a density of 0.6 × 10⁻¹² g / µm³, an effective CPG filling rate of 10%, and a unit loading capacity of 80 fmol. In contrast, the reaction unit 53 of a typical biochip has a diameter of 50µm and a height of 15µm, and a loading capacity generally lower than 10⁻¹ fmol. This increased chip unit loading capacity directly increases the number of immobilized oligonucleotides, cDNA, genomic DNA, peptides, antibodies, and antigens, expanding the detection range and throughput, increasing reaction sensitivity, and making higher throughput possible. By increasing or decreasing the photocuring time and number of times, the loading capacity of the reaction unit 53 can be adjusted according to reaction requirements, increasing or decreasing the effective CPG filling rate, thus achieving adjustable unit loading capacity.

[0051] Because the CPG carrier has a porous structure, it exhibits better flow characteristics. In conventional microfluidic chips, reagents flow on the chip carrier plane, while reagents close to the carrier surface remain stationary. Many immobilized oligonucleotides and DNA molecules are very small and reside primarily in the space near the carrier surface, resulting in insufficient reagent exchange. This is the reason for the chip's low reaction efficiency and lack of sensitivity. The chip carrier of this invention is a CPG controllable microporous glass bead. Reactants are contained within the pores, allowing for more complete reagent exchange as it flows through the micropores, thus achieving higher reaction efficiency.

[0052] Alternatively, in step S65, the photosensitive resin introduced can also be a photosensitive resin that is not resistant to acetonitrile. In this way, acetonitrile reagent can be introduced subsequently to wash away the carrier portion 54 in the reaction unit 53, so that it can be reused.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A microfluidic chip fabrication method, comprising the following steps: S1. Provide the following materials: optical engine, chip base, chip pressure plate, and glass slide; the glass slide is pressed onto the chip base by the chip pressure plate, and a closed molding space is formed between the chip base and the glass slide; the chip pressure plate is provided with an opening corresponding to the molding space; the chip base is provided with a liquid inlet channel and a liquid outlet channel communicating with the molding space; S2. Forming the main channel, branch channels and reaction units in the molding space: Turn on the optical engine and output the first photomask. The optical engine irradiates the photosensitive resin in the molding space through the first photomask for a period of time. The photosensitive resin irradiated by the optical engine is cured and formed into a fence. The main channel, branch channels and reaction units are formed between the fences. S3. Loading the carrier CPG into the reaction unit includes the following steps: S31. Inject photosensitive resin into the molding space through the liquid inlet channel; allow the photosensitive resin to flow into the reaction space along the main channel and the branch channel; S32. Turn on the optical engine and output the second photomask. The second photomask is used in conjunction with the optical engine to irradiate the photosensitive resin to cure and form a step on the outlet side of the reaction unit. The height of the step is lower than the height of the fence. The height of the step is greater than 1 CPG and less than 5 μm. S33. Clean the glass slide by introducing the cleaning reagent into the molding space through the liquid inlet channel to rinse away the photosensitive resin remaining in the molding space. S34, CPG carrier: The CPG mixture is introduced into the molding space through the liquid inlet channel, so that the CPG mixture enters the reaction unit; the CPG has a spatial porous structure, and the CPG mixture uses CPG with a micropore diameter of 50-300 nm; the CPG carrier is at least one of microporous glass beads and microporous magnetic beads. S35. Photosensitive resin is introduced into the molding space through the liquid inlet channel, so that it enters the reaction unit. S36. Turn on the optical engine and output the third photomask. The third photomask is used in conjunction with the optical engine to irradiate and solidify the photosensitive resin loading carrier CPG in the reaction unit. After solidification, the photosensitive resin is in the form of horizontal sheets, vertical sheets, or grid pattern. S37. Clean the glass slide by introducing the cleaning reagent into the molding space through the liquid inlet channel to rinse away the photosensitive resin and carrier CPG remaining in the molding space, thus completing the curing of the carrier CPG.

2. The microfluidic chip fabrication method according to claim 1, characterized in that, In step S35, the photosensitive resin introduced is a photosensitive resin that is not resistant to acetonitrile.

3. The microfluidic chip fabrication method according to claim 1, characterized in that, In step S36, the photosensitive resin is cured into a multi-layered transverse sheet, including the following steps: the photosensitive resin and carrier CPG are cured to form a cured bottom layer through steps S35 and S36; then steps S35 and S36 are repeated to sequentially stack and cure on the cured bottom layer.

4. The microfluidic chip fabrication method according to claim 1, characterized in that, The CPG mixed reagent is a CPG suspension dissolved with a loading of 100 μmol / g to 25 μmol / g.

5. A microfluidic chip fabrication method according to claim 1, characterized in that, In step S3, the carrier CPG is loaded into all or part of the reaction units.

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