A polydimethylsiloxane microfluidic chip through-hole forming jig and method

Abstract

The embodiment of the present invention discloses a polydimethylsiloxane microfluidic chip through-hole forming jig and method, which uses elastic placeholder pins in combination with a jig to form PDMS through-holes. The through-holes are directly formed when the PDMS prepolymer is poured. After the PDMS prepolymer is solidified, the placeholder pins are removed to form the through-holes. The position of the through-hole is determined by a positioning member, and no manual visual alignment is required, thereby realizing standardized and batch production of through-hole formed parts. The placeholder pin has a certain elastic stroke in the assembly through-hole of the needle assembly portion on the positioning member, which can ensure that the placeholder pin is close to the bottom surface of the casting area. The height of the through-hole can be controlled by the positioning member, that is, the distance between the chamfered root platform of the positioning member and the bottom plate of the casting area on the bottom surface of the accommodating cavity is the height of the through-hole.

Description

Technical Field

[0001] The present invention relates to the technical field of microfluidic chip manufacturing, and in particular to a polydimethylsiloxane microfluidic chip through-hole forming jig and method. Background Art

[0002] Polydimethylsiloxane (PDMS) is a polymer silicone material that has received widespread attention and application in the fields of biology and chemistry. PDMS can be used to make microfluidic chips. Compared with other materials, such as silicon wafers, glass, quartz, PMMA, etc., PDMS has good chemical inertness and good biocompatibility, and is low-cost and easy to process. Currently, the method for making through holes in PDMS microfluidic chips mainly uses a metal needle to punch holes, and then manually applies pressure to cut away the local PDMS at the corresponding position after visual alignment to form a through hole [Li S, Chen S. Polydimethylsioxane fluidic interconnects for microfluidic systems [J]. IEEE Transactions on advanced Packaging, 2003, 26 (3): 242-247]. Due to the high elasticity of PDMS material, it is easy for the PDMS to deform during the punching process, causing the punching position to shift, and even damage the structure of the microfluidic chip.

[0003] The improved method is to place a micro-pillar to form a through-hole structure when pouring the PDMS prepolymer with the assistance of magnetic force (CN101585507A). Although this method avoids secondary hole opening, the placement of the micro-pillar still requires manual visual alignment, which makes it difficult to achieve standardized and batch production of through-hole molded parts. In addition, the height of the PDMS through-hole produced by this method still depends on the thickness of the poured PDMS. The PDMS prepolymer has high viscosity and the addition amount is poorly controlled, which makes it difficult to control the overall thickness of the PDMS. The high uncertainty of the PDMS through-hole height will bring some difficulties to automated sampling. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a polydimethylsiloxane microfluidic chip through-hole forming jig to solve the technical problems of the current polydimethylsiloxane microfluidic chip through-hole forming technology, such as the difficulty in achieving standardization and batch production and the high uncertainty of through-hole height.

[0005] In order to achieve the purpose of the present invention, the technical solution adopted by the present invention is:

[0006] The present invention provides a polydimethylsiloxane microfluidic chip through-hole forming jig, which includes: a main body, at least one positioning member and at least one placeholder needle. The main body is provided with a receiving cavity, and the at least one positioning member is assembled to a predetermined position on the main body and spans the receiving cavity. Each positioning member is equipped with at least one placeholder needle, and the placeholder needle is inserted into the receiving cavity from under the positioning member.

[0007] Furthermore, the positioning member includes a spanning portion, end portions extending from an outer end of the spanning portion to both sides, and a needle assembly portion located at a predetermined position of the spanning portion.

[0008] Preferably, the end portion is arranged perpendicular to the spanning portion.

[0009] Preferably, a recessed portion is provided at a predetermined position of the assembly positioning piece on the body, and the end portion is assembled into the recessed portion.

[0010] Preferably, a limiting hole is provided in the recessed portion, a protruding limiting column is provided below the end portion, and the limiting column is inserted into the limiting hole.

[0011] Preferably, magnets are installed at the lower end of the limiting post and in the limiting hole, and the limiting post is inserted into the limiting hole by magnetic attraction.

[0012] Preferably, the needle assembly portion comprises: an assembly through hole and an extension portion located below the spanning portion, and the assembly through hole passes through the spanning portion and the assembly through hole of the extension portion.

[0013] Preferably, the extension portion transitions and extends downward to form a chamfer, and a platform is provided outwardly at the root of the chamfer.

[0014] Preferably, the spacer pin is installed in the assembly through hole via a fixing member, and an elastic member is provided between the fixing member and the spacer pin.

[0015] Preferably, a communicating opening is provided around the periphery of the accommodating cavity.

[0016] The present invention also provides a method for forming through-holes in a polydimethylsiloxane microfluidic chip, the method comprising: assembling at least one positioning member to a predetermined position on a main body, each positioning member spanning a receiving cavity on the main body; assembling at least one placeholder needle on each positioning member, each placeholder needle being inserted into the receiving cavity from under the positioning member; pouring polydimethylsiloxane prepolymer into the receiving cavity; and after the polydimethylsiloxane prepolymer is cured, removing the placeholder needle and the positioning member, thereby peeling off the polydimethylsiloxane microfluidic chip with the through-hole.

[0017] Preferably, the positioning member has ends formed by extending the outer end toward both sides and is assembled into a recessed portion at a predetermined position of the body.

[0018] Preferably, the end portion is inserted into the limiting hole in the recessed portion through a limiting column provided below.

[0019] Preferably, the limiting column is attracted to the magnet in the limiting hole through the magnet at the lower end.

[0020] Preferably, the placeholder needle is inserted into the assembly through hole of the needle assembly portion on the positioning member, and the needle assembly portion is provided with an extension portion below the spanning portion of the positioning member, and the assembly through hole passes through the spanning portion and the extension portion, and the extension portion transitions downward to form a chamfer, and a platform is provided outward at the root of the chamfer, and the height of the poured polydimethylsiloxane prepolymer is higher than the platform, forming a chip through hole with a funnel shape, and the height of the chip through hole is equal to the distance between the platform and the bottom surface of the accommodating cavity.

[0021] Preferably, the placeholder pin is inserted into the assembly through hole of the needle assembly portion on the positioning member, the upper part of the placeholder pin is fastened by a fixing member, an elastic member is provided between the fixing member and the placeholder pin, and the placeholder pin has a preset elastic stroke. The deformation of the elastic member is adjusted by the fixing member so that when the positioning member is assembled to the main body, the lower end of the placeholder pin is in contact with the bottom surface of the accommodating cavity.

[0022] Compared with the prior art, the embodiment of the present invention uses elastic placeholder pins in combination with a jig to produce PDMS through-holes. The through-holes are directly produced when the PDMS prepolymer is poured. After the PDMS prepolymer is solidified, the placeholder pins are removed to form the through-holes. The position of the through-hole is determined by the positioning piece, and no manual visual alignment is required, thus realizing the standardized and batch production of through-hole molded parts. The placeholder pin has a certain elastic stroke in the assembly through-hole of the needle assembly portion on the positioning piece, which can ensure that the placeholder pin is close to the bottom surface of the casting area. The height of the through-hole can be controlled by the positioning piece, that is, the distance between the chamfered root platform of the positioning piece and the bottom plate of the casting area on the bottom surface of the accommodating cavity is the height of the through-hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. Some specific embodiments of the present application will be described in detail in an illustrative and non-restrictive manner with reference to the drawings. The same reference numerals in the drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings:

[0024] Figure 1This is a schematic structural diagram of a polydimethylsiloxane microfluidic chip through-hole forming jig disclosed in the present invention;

[0025] Figure 2 This is a schematic diagram of the assembly of a polydimethylsiloxane microfluidic chip through-hole forming jig disclosed in the present invention;

[0026] Figure 3 A top view of a polydimethylsiloxane microfluidic chip through-hole forming jig disclosed in the present invention;

[0027] Figure 4 The present invention discloses a cross-sectional view of a polydimethylsiloxane microfluidic chip through-hole forming jig.

[0028] In the above drawings:

[0029] 1. Main body; 11. Accommodating cavity; 12. Recessed portion; 13. Opening; 14. Limiting hole; 2. Positioning member; 21. Spanning portion; 22. End portion; 23. Needle assembly portion; 231. Assembly through hole; 232. Extension portion; 233. Chamfer; 234. Platform; 24. Limiting column; 3. Placeholder needle; 4. Magnet; 5. Elastic member; 6. Fixing member. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0031] The polydimethylsiloxane microfluidic chip through-hole forming involved in the embodiment of the present invention specifically refers to: forming a through-hole at one time while the PDMS prepolymer is solidifying, which can be used as the sampling hole, sampling hole or other required through-hole of the PDMS microfluidic chip. The current polydimethylsiloxane microfluidic chip through-hole forming technology requires manual visual alignment, which makes it difficult to achieve standardized and mass production. The through-hole height still depends on the thickness of the cast PDMS. The PDMS prepolymer has a high viscosity and the addition amount is poorly controlled, which makes it difficult to control the overall thickness of the PDMS and the through-hole height uncertainty is high. In order to overcome the above technical problems.

[0032] refer to Figures 1 to 3 The embodiment of the present invention discloses a polydimethylsiloxane microfluidic chip through-hole forming fixture, which includes: a body 1, a positioning member 2 and a placeholder needle 3.

[0033] The materials used to make the body 1 include, but are not limited to, metal, plastic, and rubber. Examples of metal include, but are not limited to, aluminum, stainless steel, and titanium alloys. The body 1 is provided with a receiving cavity 11 for accommodating a polydimethylsiloxane prepolymer, which, upon curing, forms a polydimethylsiloxane microfluidic chip.

[0034] The materials used to make the positioning member 2 also include, but are not limited to, metal, plastic, and rubber. Examples of metal include, but are not limited to, aluminum, stainless steel, and titanium alloys. The positioning member 2 is assembled to a predetermined position on the body 1 and spans the accommodating cavity 11. The positioning member 2 comprises a spanning portion 21, an end portion 22, and a needle mounting portion 23. The end portion 22 extends from the outer end of the spanning portion 21, and the needle mounting portion 23 is located at a predetermined position on the spanning portion 21.

[0035] A recessed portion 12 is provided at a predetermined position on the body 1 where the positioning member 2 is assembled. The inner contour of the recessed portion 12 matches the outer contour of the end portion 22 , and the end portion 22 is assembled into the recessed portion 12 .

[0036] Preferably, a limiting hole 14 is provided in the recessed portion 12, and a protruding limiting post 24 is provided below the end portion 22, which is inserted into the limiting hole 14. The limiting assembly of the limiting post 24 and the limiting hole 14 allows the positioning member 2 to be stably assembled to the predetermined position of the body 1. During the through-hole molding process of the polydimethylsiloxane microfluidic chip, the stability of the positioning member 2 and the spacer pin 3 is ensured, and the influence of shaking on the through-hole molding is avoided.

[0037] like Figures 1 to 3 As shown, the spanning portion 21 is elongated, with the end portion 22 disposed perpendicularly thereto. The end portion 22 and the spanning portion 21 form an "I" shape, which facilitates the assembly stability of the positioning member 2. Furthermore, the "I" shape allows the positioning member 2 to be assembled horizontally into the accommodating cavity 11 of the body 1, thus enabling the spacer pin 3 to be assembled vertically onto the positioning member 2, ensuring that the resulting through-hole remains vertical.

[0038] refer to Figure 2 There are four limiting columns 24, and a limiting column 24 is respectively provided at the lower part of each end 22. Correspondingly, the number of limiting holes 14 is also four, and two limiting holes 14 are provided in each recessed portion 12. There is a limiting mechanism between the positioning member 2 and the main body 1, that is, the positioning member 2 is respectively inserted into the four limiting holes 14 in the two recessed portions 12 on the main body 1 through the four limiting columns 24 under the two end portions 22.

[0039] refer to Figure 2The lower end of the limiting post 24 and the limiting hole 14 are both equipped with magnets 4. The limiting post 24 is inserted into the limiting hole 14 by magnetic attraction. In this way, the positioning member 2 and the main body 1 are locked by magnetism. There are eight magnets in total, four of which are installed in the four limiting holes 14 in the two recessed portions 12 on the main body 1, and the other four magnets are installed under the four limiting posts 24 under the two ends 22 of the positioning member 2. When the positioning member 2 is closed with the main body 1, the eight magnets attract each other in pairs, thereby fixing the positioning member 2.

[0040] refer to Figure 1 and Figure 2 The pin mounting portion 23 includes a mounting hole 231 and an extension portion 232. The extension portion 232 is cylindrical and located below the spanning portion 21 where the placeholder pin 3 is mounted. It surrounds the placeholder pin 3, protecting it and maintaining its vertical position. The mounting hole 231 extends through the spanning portion 21 and the extension portion 232 and is used to mount the placeholder pin 3.

[0041] The spacer pin 3 is assembled on the positioning member 2 and inserted into the accommodating cavity 11 from the bottom of the positioning member to form a through hole simultaneously when the PDMS prepolymer is cured. As mentioned above, specifically, the spacer pin 3 is inserted into the assembly through hole 231 of the needle assembly portion 23 of the positioning member 2. Figure 2 Placeholder pin 3 has a tail that is thicker than the main body, forming a step where the tail meets the main body. The mounting hole 231 matches the shape of placeholder pin 3, thus providing a mounting step. Placeholder pin 3 is inserted into the mounting hole 231 via the step, preventing it from slipping out.

[0042] The placeholder pin 3 is installed in the assembly through hole 231 through the fixing member 6. Figures 1 to 4 As shown, the fixing member is a fixing screw, and the placeholder pin 3 is installed into the assembly through hole 231 from the top through the fixing screw. Figure 2 Preferably, an elastic member 5 is disposed between the fixing member 6 and the spacer pin 3. The elastic member 5 can be a spring, with its upper end connected to the lower portion of the fixing member 6 and its lower end connected to the tail of the spacer pin 3, thereby providing the spacer pin 3 with a predetermined elastic travel. Furthermore, the elastic member 5 designed in the embodiment of the present invention can be made of any elastic material. In addition to metal springs, it can also be made of an elastic polymer material or a pair of mutually exclusive magnetic materials.

[0043] refer to Figure 1 、 Figure 2 and Figure 4Preferably, the extension portion 232 transitions downward to form a chamfer 233, and a platform 234 is provided outward at the root of the chamfer 233. The chamfer 233 makes the formed chip through hole have a funnel shape. The chamfer 233 can be designed as needed. The height of the poured polydimethylsiloxane prepolymer is higher than the platform 234. In this way, Figure 4 As shown, the height of the chip through hole is equal to the distance h between the platform 234 and the bottom surface of the accommodating cavity 11.

[0044] refer to Figure 1 、 Figure 2 and Figure 3 Preferably, a communicating opening 13 is provided around the accommodating cavity 11. The opening 13 is preferably provided near the needle assembly portion 23 for removing the placeholder needle 3 from the opening 13 after the PDMS prepolymer is cured.

[0045] In order to solve the above problems, corresponding to the above-disclosed polydimethylsiloxane microfluidic chip through-hole forming jig, an embodiment of the present invention further discloses a polydimethylsiloxane microfluidic chip through-hole forming method.

[0046] A method for forming through-holes in a polydimethylsiloxane microfluidic chip disclosed in an embodiment of the present invention includes: assembling a positioning member 2 to a predetermined position on a main body 1, the positioning member 2 spanning a receiving cavity 11 on the main body 1; assembling a placeholder needle 3 on the positioning member 2, the placeholder needle 3 being inserted into the receiving cavity 11 from below the positioning member 2; pouring a polydimethylsiloxane prepolymer into the receiving cavity 11; and after the polydimethylsiloxane prepolymer is cured, removing the placeholder needle 3 and the positioning member 2, thereby peeling off the polydimethylsiloxane microfluidic chip with the through-hole.

[0047] The positioning member 2 is assembled into the recessed portion 12 at a predetermined position of the main body 1 through the end portion 22 formed by extending the outer end to both sides. Preferably, the end portion 22 is inserted into the limiting hole 14 in the recessed portion 12 through the limiting column 24 provided below. Furthermore, the limiting column 24 is attracted to the magnet 4 in the limiting hole 14 through the magnet 4 at the lower end. Through the limiting assembly of the limiting column 24 and the limiting hole 14, the positioning member 2 is stably assembled to the predetermined position of the main body 1. During the through-hole molding and manufacturing process of the polydimethylsiloxane microfluidic chip, the stability of the positioning member 2 and the placeholder needle 3 is ensured, and the influence of shaking on the through-hole molding is avoided.

[0048] The placeholder pin 3 is inserted into the assembly through hole 231 of the pin assembly portion 23 on the positioning member 2. The pin assembly portion 23 is provided with an extension portion 232 below the spanning portion 21 of the positioning member 2. The assembly through hole 231 passes through the spanning portion 21 and the extension portion 232. The extension portion 232 transitions downward and extends to form a chamfer 233. A platform 234 is provided outward at the root of the chamfer 233. The height of the poured polydimethylsiloxane prepolymer is higher than the platform 234, forming a chip through hole with a funnel shape. Figure 4The chip through hole height is equal to the distance h between the platform 234 and the bottom surface of the accommodating cavity 11.

[0049] Preferably, the placeholder needle 3 is inserted into the assembly through hole 231 of the needle assembly portion 23 on the positioning member 2, and the upper part of the placeholder needle 3 is fastened by the fixing member 6. An elastic member 5 is provided between the fixing member 6 and the placeholder needle 3. The placeholder needle 3 has a preset elastic stroke. The deformation of the elastic member 5 is adjusted by the fixing member 6 so that when the positioning member 2 is assembled to the main body 1, the lower end of the placeholder needle 3 is in contact with the bottom surface of the accommodating cavity 11.

[0050] Figures 1 to 4 While only one positioning member 2 is shown, with each positioning member 2 fitted with a single placeholder pin 3, this does not mean that this embodiment of the present invention is limited to forming a single through-hole in the PDMS material. According to this embodiment of the present invention, different sizes of main bodies 1 and positioning members 2 can be designed, thereby creating a jig capable of forming a specified number of through-holes at predetermined locations. Thus, multiple positioning members 2 can be fitted to the main body 1, and multiple placeholder pins 3 can be fitted to a single positioning member 2.

[0051] The embodiment of the present invention uses elastic placeholder pins in combination with a jig to produce PDMS through-holes. The through-holes are produced directly when the PDMS prepolymer is poured. After the PDMS prepolymer is solidified, the placeholder pins are removed to form the through-holes. The position of the through-hole is determined by a positioning member, and no manual visual alignment is required, thereby realizing standardized and batch production of through-hole molded parts. The placeholder pin has a certain elastic stroke in the assembly through-hole of the needle assembly portion on the positioning member, which can ensure that the placeholder pin is close to the bottom surface of the casting area. The height of the through-hole can be controlled by the positioning member, that is, the distance between the platform at the chamfered root of the positioning member and the bottom plate of the casting area on the bottom surface of the accommodating cavity is the height of the through-hole. The transition chamfer between the platform formed at the chamfered root of the lower edge of the needle assembly portion and the placeholder pin makes the formed chip through-hole have a funnel shape, which facilitates the program-controlled insertion of the injection needle during automated sampling. Magnetic locking is used between the positioning member and the main body to ensure the accuracy of the relative position of the two.

[0052] In this embodiment of the present invention, the height of the through-hole is defined as the distance between the chamfered base platform of the positioning element and the bottom plate of the casting area on the bottom surface of the chamber. This height is independent of the overall height of the PDMS microfluidic chip and, consequently, the amount of PDMS prepolymer introduced during casting. This ensures controllable and precise height of the through-hole, facilitating height control of the sample injection device during automated sampling.

[0053] This embodiment of the present invention eliminates the need for secondary hole drilling after the PDMS prepolymer cures. Instead, through-holes are formed using spacer pins while the PDMS prepolymer cures. Once the PDMS prepolymer cures, the spacer pins are removed to complete the through-hole placement, ensuring accurate through-hole placement. The through-hole position is controlled by the positioning of the positioning element and the spacer pins, eliminating the risk of human error.

[0054] Finally, it should be noted that 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polydimethylsiloxane microfluidic chip through-hole forming jig, characterized in that: The fixture comprises: a body, at least one positioning member, and at least one spacer pin; the body is provided with an accommodating cavity; the at least one positioning member is assembled to a predetermined position on the body and spans the accommodating cavity; each positioning member is equipped with at least one spacer pin, and the spacer pin is inserted into the accommodating cavity from below the positioning member; The positioning member includes a spanning portion, an end portion extending from the outer end of the spanning portion to both sides, and a needle assembly portion located at a predetermined position of the spanning portion. A recessed portion is provided at a predetermined position on the body for assembling the positioning member, and the end portion is assembled into the recessed portion. A limiting hole is provided in the recessed portion, and a protruding limiting column is provided below the end portion, and the limiting column is inserted into the limiting hole; The lower end of the limiting post and the limiting hole are both equipped with magnets, and the limiting post is inserted into the limiting hole by magnetic attraction; the needle assembly portion includes: an assembly through hole and an extension portion located below the spanning portion, and the assembly through hole passes through the assembly through holes of the spanning portion and the extension portion; The spacer pin is installed in the assembly through hole through a fixing piece, and an elastic piece is provided between the fixing piece and the spacer pin.

2. A polydimethylsiloxane microfluidic chip through-hole forming jig according to claim 1, characterized in that: The extension portion transitions and extends downward to form a chamfer, and a platform is provided outwardly at the root of the chamfer.

3. A polydimethylsiloxane microfluidic chip through-hole forming jig according to claim 1, characterized in that: A communicating opening is provided around the accommodating cavity.

4. A method for forming through-holes in a polydimethylsiloxane microfluidic chip, characterized in that: The method comprises: Assembling at least one positioning member to a predetermined position on the body, wherein each positioning member spans the receiving cavity on the body; At least one spacer pin is assembled on each positioning member, and each spacer pin is inserted into the accommodating cavity from below the positioning member; pouring polydimethylsiloxane prepolymer into the receiving cavity; and After the polydimethylsiloxane prepolymer is cured, the spacer needles and the positioning piece are removed to peel off the polydimethylsiloxane microfluidic chip with through holes; The positioning member includes a spanning portion, ends extending from the outer end of the spanning portion to both sides, and a needle assembly portion located at a predetermined position of the spanning portion. A recessed portion is provided at a predetermined position on the body for assembling the positioning member, and the end portion is assembled into the recessed portion. A limiting hole is provided in the recessed portion, and a protruding limiting column is provided below the end portion, and the limiting column is inserted into the limiting hole; The lower end of the limiting post and the limiting hole are both equipped with magnets, and the limiting post is inserted into the limiting hole by magnetic attraction; The needle assembly portion includes: an assembly through hole and an extension portion located below the spanning portion, wherein the assembly through hole passes through the assembly through holes of the spanning portion and the extension portion; The spacer pin is installed in the assembly through hole through a fixing piece, and an elastic piece is provided between the fixing piece and the spacer pin.

5. A method for forming through-holes in a polydimethylsiloxane microfluidic chip according to claim 4, characterized in that: The positioning piece is assembled into a recessed portion at a predetermined position of the main body by extending the end portion formed by the outer end to both sides, and the end portion is inserted into the limiting hole in the recessed portion through a limiting column arranged below, and the limiting column is attracted to the magnet in the limiting hole through the magnet at the lower end.

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