A combined PDMS microfluidic chip

Abstract

This invention relates to a modular PDMS microfluidic chip, comprising a metal cup, a glass-bonded PDMS microfluidic chip, a back cover, and a locking countersunk screw. The metal cup is embedded and sealed with the PDMS substrate of the glass-bonded PDMS microfluidic chip. The glass and PDMS substrate, with microchannels etched on them, are plasma-bonded to form the glass-bonded PDMS microfluidic chip, with the glass surface of the glass-bonded PDMS microfluidic chip in contact with the back cover. The back cover is locked to the metal cup by the locking countersunk screw. This invention allows for the replacement of the microfluidic channels by changing the silicon wafer used in the PDMS curing process, saving the cost and time of modifying molds during the R&D process. The metal cup is fully compatible with the sample slot installation of current single-cell sequencers, saving equipment costs. Simultaneously, the metal cup is reusable and has high rigidity and strength. The radial sealing method of the metal cup and the glass-bonded PDMS microfluidic chip with a conical surface maximizes the protection of the PDMS substrate chip and ensures reliable sealing.

Description

Technical Field

[0001] This invention relates to a microfluidic chip for single-cell sequencing instruments, specifically a combined PDMS microfluidic chip for droplet generation in single-cell sequencing instruments. Background Technology

[0002] In the process of preparing single-cell emulsions, single-cell sequencers require the aqueous phase, oil phase, and microsphere phase to be passed through the microfluidic chip channels in a specific ratio. Throughout the droplet generation process, the microfluidic chip, being a disposable consumable, requires adjustments to its microfluidic channel structure based on experimental results during the research and validation phases. Injection-molded chips, on the other hand, require modifications to the injection mold, which is expensive and time-consuming, slowing down the development of the microfluidic channels.

[0003] The main body of a single-cell sequencing instrument is equipped with a matching injection-molded chip. Polydimethylsiloxane (PDMS) microfluidic chips cannot be directly installed on the chip holder of a single-cell sequencing instrument. Additional pressure control and output equipment are required to insert the PDMS microfluidic chip separately, which is cumbersome and requires additional equipment and software costs. Summary of the Invention

[0004] The technical problem this invention aims to solve is that when developing new microfluidic chip flow channels, modifying the flow channels of injection-molded chips requires significant expenses for modifying the injection molds and also takes considerable time, greatly extending development costs. The modular PDMS microfluidic chip can significantly reduce the costs associated with modifying the channels, saving both development costs and time for microfluidic chips.

[0005] The present invention includes a metal cup mouth, a glass-bonded PDMS microfluidic chip, a back cover plate, and a locking countersunk screw; the metal cup mouth and the PDMS substrate of the glass-bonded PDMS microfluidic chip are embedded and sealed; the glass and the PDMS substrate with microchannels are plasma bonded together to form the glass-bonded PDMS microfluidic chip, and the glass surface of the glass-bonded PDMS microfluidic chip is in contact with the back cover plate; the back cover plate is locked to the metal cup mouth by the locking countersunk screw.

[0006] The beneficial effects of this invention are as follows:

[0007] Glass-bonded PDMS microfluidic chips can achieve low-cost replacement of microfluidic channels by replacing the silicon wafer in the PDMS curing process, saving the cost and time of modifying molds during the research and development process.

[0008] The metal cup mouth is machined from aluminum alloy, and the entire outer surface is coated with a hydrophobic layer. After the modular PDMS microfluidic chip is placed in the single-cell sequencing instrument for testing, it can be reused by cleaning and drying with organic solutions, saving on cup mouth replacement costs. The structural rigidity and strength of the metal cup mouth are far greater than those of disposable plastic microfluidic chips, resulting in less deformation and greater reliability during the compression and sealing process in the single-cell sequencing instrument.

[0009] The composite PDMS microfluidic chip has a conical array of sealing contact surfaces on the back of the cup opening, which enables radial sidewall sealing between the array of cylindrical holes of the glass-bonded PDMS microfluidic chip and the conical column array. It can achieve a good sealing effect without the need for a back cover to provide the sealing pressure, effectively preventing the glass-bonded PDMS microfluidic chip from breaking. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structural combination and explosion of an embodiment of this application.

[0011] Figure 2 These are front and back views of the metal cup opening according to an embodiment of this application.

[0012] Figure 3 This is a view of a glass-bonded PDMS microfluidic chip according to an embodiment of this application. Detailed Implementation

[0013] This application provides a combined PDMS microfluidic chip for a single-cell sequencer. The combined chip has a metal cup mouth, and an array of protruding conical pillars on the back of the metal cup mouth. The conical pillars have through holes in the middle that communicate with the cavity of the cup mouth. The PDMS surface of the glass-bonded PDMS microfluidic chip has arrayed holes that fit into the conical pillars on the back of the metal cup mouth. The PDMS surface of the glass-bonded PDMS microfluidic chip has arrayed holes that communicate with microchannels etched on a PDMS substrate. The surface of the PDMS substrate with etched microchannels and the glass are plasma-bonded to form a sealed microchannel. The back cover is installed on the corresponding mounting position of the metal cup mouth by locking countersunk screws and is pressed against the glass surface of the glass-bonded PDMS microfluidic chip.

[0014] In a preferred embodiment, the cavity of the metal cup has a protruding edge with a thinner wall and a height set to half the thickness of the sealing gasket. Under the same sealing and pressing force, the deformation of the sealing gasket is increased, thus improving the sealing performance.

[0015] In a preferred embodiment, an array of sealing conical pillars is provided on the back of the metal cup mouth. The outer conical surface of the conical pillars fits into an array of cylindrical holes on the PDMS substrate. The top of the conical pillar is smaller than the cylindrical hole on the PDMS substrate, while the bottom is larger than the cylindrical hole on the PDMS substrate. This facilitates the alignment of the array holes during installation. At the same time, the larger bottom of the conical pillar ensures that the sidewall of the cylindrical hole on the PDMS substrate is subjected to sufficient compression deformation, thus ensuring the sealed fit between the metal cup mouth and the glass-bonded PDMS microfluidic chip.

[0016] In a preferred embodiment, two grooved support pillars are provided on the back of the metal cup mouth. The support pillars are beneficial for supporting the deformation of the combined chip span when the metal cup mouth is compressed in the single-cell sequencer, and also provide initial positioning for the embedding process with the glass-bonded PDMS microfluidic chip.

[0017] In a preferred embodiment, the entire metal cup mouth is coated with a Teflon coating, which has good hydrophobicity and surface roughness, ensuring that the solution in the cup mouth cavity will not leave residue on the wall, and also making the seal at the contact point between the array's conical surface and the PDMS substrate more reliable.

[0018] In a preferred embodiment, a countersunk hole is provided on the back cover plate. The thickness of the back cover plate is less than the height of the metal cup mounting groove, and the thickness of the glass-bonded PDMS microfluidic chip is also slightly less than the thickness of the chip mounting cavity of the metal cup. This ensures that when the back cover plate is installed on the back of the metal cup by tightening the countersunk screws, the glass-bonded PDMS microfluidic chip will not be squeezed by a large screw preload, thus protecting the glass-bonded PDMS microfluidic chip. On the other hand, after the back cover plate is installed, the highest plane on the back of the combined PDMS microfluidic chip is still the metal cup itself, ensuring the flatness and parallelism of the combined PDMS microfluidic chip when placed on the single-cell sequencer.

[0019] The following are embodiments of the present invention with reference to the accompanying drawings:

[0020] See Figure 1 The diagram shows the structural assembly and explosion of this embodiment. The conical column on the back of the metal cup mouth 1 is embedded with the glass-bonded PDMS microfluidic chip 2. The back cover plate 3 is fixed to the metal cup mouth 1 by locking countersunk screws 4. After the back cover plate 3 is locked, it fits tightly with the glass-bonded PDMS microfluidic chip 2 to prevent the glass-bonded PDMS microfluidic chip 2 from detaching from the metal cup mouth 1.

[0021] See Figure 2The following are front and back views of the metal cup mouth in an embodiment of this application. The front side 1-a of the metal cup mouth is provided with a cup mouth cavity 1-1 for holding solutions of each phase. The edge of the cup mouth cavity is provided with a circular protrusion edge 1-2, and the side is provided with a chip mounting slot 1-3 for fixing a single-cell sequencer. The chip cavity on the back side 1-b of the metal cup mouth is provided with an array of conical pillars 1-4, a support positioning pillar 1-5 in the middle, and mounting threaded holes 1-6 around the perimeter for locking the back cover plate 3.

[0022] See Figure 3 The image shows a glass-bonded PDMS microfluidic chip according to an embodiment of this application. The PDMS substrate 2-a of the glass-bonded PDMS microfluidic chip has a cylindrical hole 2-1. The microchannels 2-2 etched on the back of the PDMS substrate 2-a are connected to the outside through the cylindrical hole 2-1, and the microchannels are sealed by plasma-bonded glass 2-b.

[0023] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although modifications or equivalent substitutions may be made to the technical solutions of the present invention with reference to preferred embodiments, they shall not depart from the spirit and scope of the technical solutions of the present invention and shall be covered within the scope of the claims of the present invention.

Claims

1. A combined PDMS microfluidic chip, characterized in that, Includes a metal cup mouth, a glass-bonded PDMS microfluidic chip, a back cover, and a locking countersunk screw; The metal cup mouth is embedded and sealed with the PDMS substrate of the glass-bonded PDMS microfluidic chip; the glass and the PDMS substrate with microchannels are plasma bonded to form the glass-bonded PDMS microfluidic chip, and the glass surface of the glass-bonded PDMS microfluidic chip is in contact with the back cover plate; the back cover plate is locked to the metal cup mouth by tightening countersunk screws.

2. The combined PDMS microfluidic chip according to claim 1, characterized in that, The metal cup has a cavity on its front side, and the cavity has a protruding edge. Sample mounting slots are provided on both sides of the metal cup.

3. The combined PDMS microfluidic chip according to claim 1, characterized in that, The chip cavity on the back of the metal cup is provided with an array of conical pillars, which are connected to the cup opening through a central through hole.

4. The combined PDMS microfluidic chip according to claim 1, characterized in that, The chip cavity on the back of the metal cup has a groove-shaped positioning support post at its center, and mounting holes and support protrusions at its four corners that are offset from the back cover plate.

5. A combined PDMS microfluidic chip according to claim 1, characterized in that, The glass-bonded PDMS microfluidic chip has cylindrical holes arrayed corresponding to the back of the metal cup opening.

6. A combined PDMS microfluidic chip according to claim 1, characterized in that, The back cover plate is fixed to the metal cup mouth by a countersunk screw and is in contact with the glass of the glass-bonded PDMS microfluidic chip.

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