Microfluidic droplet storage chip

Abstract

The utility model discloses a micro -fluidic droplet storage chip, first substrate and second substrate, the lower surface of first substrate is provided with first channel, the upper surface of second substrate is provided with second channel, first channel and second channel are used for storing droplet, the lower surface of first substrate and the upper surface of second substrate are communicated up and down on the channel junction of first channel and second channel constitution, first substrate and second substrate can constitute through specific channel pattern bonding, and the process compatibility is strong. The design makes it can be used as an independent droplet storage and culture module alone, also can be integrated into the existing micro -fluidic system seamlessly because of its standardized planar interface, realizes high -efficient combination with the droplet generation module of upstream, the droplet detection, analysis and screening module of downstream, greatly expands its application flexibility.

Description

Technical Field

[0001] This utility model relates to the field of biomanufacturing technology, and in particular to a microfluidic droplet storage chip. Background Technology

[0002] Microfluidics technology manipulates fluids through micrometer-scale channel networks to achieve functions such as mixing, separation, and reaction. Droplet microfluidics is an important branch of this technology, utilizing two immiscible phases (such as water and mineral oil) to form monodisperse droplets under the influence of shear forces or electric fields within the channels. Microfluidic droplet technology has wide applications in biomedicine, chemical synthesis, and high-throughput screening due to its high throughput, low sample consumption, and precise manipulation capabilities. However, traditional microfluidic systems typically focus on droplet generation, manipulation, and immediate detection, while long-term droplet storage remains a key challenge. Research on droplet storage units aims to address issues such as stable droplet encapsulation, high-density arrangement, and controlled release to enable more complex experimental procedures (such as multi-step reactions, long-term incubation, or subsequent analysis).

[0003] Currently, the main ways to realize droplet storage units include the following categories: microchamber arrays, oil phase encapsulation storage, gel solidification storage, and surface modification and patterning. The above methods cannot achieve an integrated approach that can be used for droplet detection and sorting as well as for storing droplets for cultivation. They also cannot overcome the problems of long-term droplet storage, droplet stability, and controllable droplet release. Summary of the Invention

[0004] The problem to be solved by this utility model embodiment is to provide a microfluidic droplet storage chip to improve the miniaturization and integration of droplet storage, and improve the efficiency of integrated droplet detection, sorting, storage and cultivation.

[0005] To address the aforementioned problems, this utility model provides a microfluidic droplet storage chip, which includes: a first substrate and a second substrate;

[0006] The first substrate and the second substrate are bonded together;

[0007] A first channel is provided on the lower surface of the first substrate;

[0008] The upper surface of the second substrate is provided with a second channel;

[0009] The first channel and the second channel are used to store droplets;

[0010] The lower surface of the first substrate and the upper surface of the second substrate are connected vertically at the junction formed by the first channel and the second channel.

[0011] Optionally, the end of the junction between the first channel and the second channel is a first inclined guide surface, and the end of the junction between the second channel and the second channel is a second inclined guide surface;

[0012] The first inclined guide surface and the first channel form a first opening, and the second inclined guide surface and the second channel form a second opening, and the first opening and the second opening are connected.

[0013] Optionally, the first inclined guide surface and the second inclined guide surface form an angle greater than 0 degrees and less than 90 degrees with the horizontal plane where the first substrate and / or the second substrate are located.

[0014] Optionally, both the first channel and the second channel are multiple curved serpentine channel structures, wherein the serpentine channel structure is formed by connecting multiple arc-shaped units in sequence to form a meandering channel.

[0015] Optionally, the first channel and the second channel occupy the maximum area of ​​the bonding surface of the first substrate and the second substrate.

[0016] Optionally, one end of the first channel is connected to the second channel, and the other end is the first sample port.

[0017] Optionally, one end of the second channel is connected to the first channel, and the other end is a second sample port.

[0018] Optionally, the first substrate and the second substrate are provided with positioning posts that penetrate through or are formed by themselves, and the central axis of the positioning posts is perpendicular to the plane of the first substrate and / or the second substrate.

[0019] The positioning post is used to fix and align the first substrate and the second substrate.

[0020] Optionally, the positioning posts are disposed on opposite sides of the first substrate and the second substrate.

[0021] Optionally, the first substrate is provided with at least one positioning post and / or at least one positioning hole, and the second substrate is provided with at least one positioning post and / or at least one positioning hole, wherein the positioning post and the positioning hole are interlocked with each other.

[0022] The technical solution provided by this utility model brings at least the following beneficial effects:

[0023] The chip has a simple structure, consisting of a first substrate and a second substrate bonded together using a specific channel pattern, resulting in strong process compatibility. This design allows it to be used independently as a droplet storage and cultivation module, or, thanks to its standardized planar interface, to be seamlessly integrated into existing microfluidic systems. It can be used efficiently in conjunction with upstream droplet generation modules and downstream droplet detection, analysis, and screening modules, greatly expanding its application flexibility.

[0024] This invention utilizes the microchannels themselves as storage chambers, confining droplets within a flat, independent microchannel space. This design effectively avoids large-area contact between droplets, significantly reducing unintended fusion caused by droplet collisions, Brownian motion, or interface disturbances. Simultaneously, the sealed channel structure greatly reduces the exposed surface area of ​​the droplets, effectively suppressing moisture evaporation and loss. Under appropriate temperature and humidity control, droplets can be stably stored within the chip for several hours to several days, providing a reliable platform for long-term cell culture, chemical reaction observation, or sample preservation.

[0025] The droplets are arranged in a linear array in the channel, rather than being randomly piled up in the chamber. This "flat" storage mode allows the droplets to be re-driven to flow on demand and sequentially, making them easy to export one by one and connect to subsequent functional chips for detection, analysis and screening. This realizes the integrated operation of the entire process from storage to analysis, and improves the automation and throughput of the entire system.

[0026] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, specific embodiments of this utility model are given below. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a microfluidic droplet storage chip provided in an embodiment of this utility model;

[0028] Figure 2 This is a schematic diagram of the channel connection in a microfluidic droplet storage chip provided in this embodiment of the present invention;

[0029] Figure 3 This is a side view of a microfluidic droplet storage chip provided in an embodiment of the present invention;

[0030] Figure 4 This is a top view schematic diagram of a microfluidic droplet storage chip provided in an embodiment of this utility model.

[0031] Explanation of reference numerals in the attached drawings: 1-First substrate; 2-Second substrate; 11-First channel; 21-Second channel; 12-First inclined guide surface; 22-Second inclined guide surface; 13-First opening; 23-Second opening; 3-First sample port; 4-Second sample port; 5-Positioning post; 6-Channel connection. Detailed Implementation

[0032] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0033] The embodiments of the present invention will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, numerous specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the present invention.

[0034] It should be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings. When the orientation of an element / component changes, "up" in the corresponding structure may change to "down." Therefore, the above description is for the purpose of clearly describing relative positions and should not be construed as absolute. The above description is also not intended to limit the scope of protection of this utility model. Throughout the accompanying drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this utility model. The shapes and dimensions of the components in the drawings do not reflect actual size and proportion, but are only schematic representations of embodiments of this utility model. Furthermore, in the claims, any reference symbols placed between parentheses should not be construed as limiting the claims.

[0035] Figure 1 This is a schematic diagram of the structure of a microfluidic droplet storage chip provided in an embodiment of this utility model; Figure 2 This is a schematic diagram of the channel connection in a microfluidic droplet storage chip provided in this embodiment of the present invention; Figure 3 This is a side view of a microfluidic droplet storage chip provided in an embodiment of the present invention; Figure 4 This is a top view schematic diagram of a microfluidic droplet storage chip provided in an embodiment of this utility model.

[0036] In the embodiments of this utility model, reference is made to Figures 1-4 1-First substrate; 2-Second substrate; 11-First channel; 21-Second channel; 12-First inclined guide surface; 22-Second inclined guide surface; 13-First opening; 23-Second opening; 3-First sample port; 4-Second sample port; 5-Positioning post; 6-Channel connection.

[0037] It should be noted that, in view of the shortcomings of the prior art, the purpose of this utility model is to provide a microfluidic droplet storage chip, which aims to solve the problems of easy fusion and evaporation of droplets, difficulty in long-term stable storage, and difficulty in integration with other functional modules of microfluidic systems in the existing droplet storage technology.

[0038] Therefore, in the first embodiment of this utility model, a microfluidic droplet storage chip is provided, the microfluidic droplet storage chip comprising: a first substrate and a second substrate;

[0039] The first substrate and the second substrate are bonded together;

[0040] A first channel is provided on the lower surface of the first substrate;

[0041] The upper surface of the second substrate is provided with a second channel;

[0042] The first channel and the second channel are used to store droplets;

[0043] The lower surface of the first substrate and the upper surface of the second substrate are connected vertically at the junction formed by the first channel and the second channel.

[0044] It should be noted that, as Figure 1 As shown, the microfluidic droplet memory chip is mainly composed of a first substrate (1) and a second substrate (2) bonded together. The first substrate (1) and the second substrate (2) can be made of transparent polymer materials, such as polymethyl methacrylate (PMMA), polycarbonate (PC) or cyclic olefin copolymer (COC), to facilitate microscopic observation and optical detection of the droplets within the chip.

[0045] The lower surface of the first substrate (1) is etched or processed with a first channel (11) by micromachining techniques (such as laser ablation, soft lithography, CNC precision machining or injection molding). The cross-section of the first channel (11) is circular, and the specific channel size can be optimized according to the required droplet volume. One end of the first channel (11) terminates at the edge of the chip, forming a first sample port (3) for the injection and discharge of droplets. Therefore, the first sample port (3) can be either an inlet or an outlet.

[0046] In this embodiment of the invention, the other end of the first channel (11) extends to a predetermined position, and its end is processed into a smooth slope, namely the first inclined guide surface (12). The first inclined guide surface (12) and the sidewall of the first channel (11) together form a first opening (13). This first opening (13) will become one of the communication ports for the flow of upper and lower droplets after future bonding.

[0047] Specifically, refer to Figure 2 , Figure 3 The first inclined guide surface (12) and the second inclined guide surface (22) are key improvements in this embodiment. They form an acute angle (α) with the horizontal plane (i.e., the substrate plane), where the angle α is greater than 0 degrees and less than 90 degrees, preferably 30° to 60°. This inclined angle ensures that when the fluid (or droplet) changes from horizontal to vertical flow (or vice versa), the change in flow direction is smooth and gradual, rather than a sudden 90-degree turn. This design greatly reduces abrupt changes in the flow field, the generation of local eddies and shear stress, thereby effectively preventing the droplet from deforming, breaking, or being damaged by internal inclusions when passing through the junction. It also helps to reduce fluid resistance and prevent sample residue.

[0048] Furthermore, referring to Figure 2 , Figure 3 The upper surface of the second substrate (2) is processed with a second channel (21) in the same manner. The size of the second channel (21) matches that of the first channel (11). One end of the second channel (21) terminates at the edge of the chip, forming a second sample port (4). The other end of the second channel (21) is also processed with a second inclined guide surface (22), forming a second opening (23).

[0049] Furthermore, both the first channel and the second channel are multiple curved serpentine channel structures, wherein the serpentine channel structure is formed by connecting multiple arc-shaped units in sequence to form a meandering channel.

[0050] It should be noted that, in this embodiment of the invention, in order to enable microdroplet storage and cultivation to be performed on the same chip, the channel for storing microdroplets needs to occupy the largest possible area on the substrate. Therefore, in this embodiment, both the first and second channels are multiple curved serpentine channel structures. Each serpentine channel structure consists of multiple arc-shaped units connected sequentially to form a meandering channel. Specifically, refer to... Figure 4 As shown, Figure 4 This is a top view of a microfluidic droplet storage chip provided in an embodiment of the present invention. It can be clearly seen that the first channel and the second channel are densely arranged and occupy the surfaces of the first substrate and the second substrate through a curved serpentine channel structure.

[0051] Specifically, both the first channel (11) and the second channel (21) are designed as serpentine channel structures. This structure consists of multiple U-shaped or arc-shaped units connected end to end to form a high-density, meandering path. This design maximizes the channel length within a limited chip planar area. Preferably, the layout of the first channel (11) and the second channel (21) should make full use of the bonding surface area of ​​the first substrate (1) and the second substrate (2) to achieve the highest storage density.

[0052] Furthermore, in one embodiment of the present invention, the first substrate is provided with at least one positioning post and / or at least one positioning hole, and the second substrate is provided with at least one positioning post and / or at least one positioning hole, wherein the positioning post and the positioning hole are fitted together.

[0053] like Figure 1 , 4 As shown, in order to ensure that the first substrate (1) and the second substrate (2) can be precisely aligned during bonding, especially to achieve perfect interconnection at the channel connection (6), this utility model is provided with a positioning structure.

[0054] Specifically, in one example given in this embodiment, the positioning structure includes positioning posts (5) disposed on opposite sides of the chip. Specifically, the two positioning posts (5) can be integrally formed on the first substrate (1) and protrude upward perpendicular to the plane of the substrate.

[0055] Furthermore, in addition to the positioning post structure, this embodiment of the invention can also include a positioning post plus positioning hole structure. For example, two positioning holes are machined at corresponding positions on the second substrate (2). The outer diameter of the positioning post (5) and the inner diameter of the positioning hole are fitted with an interference fit or a transition fit to ensure that the two substrates do not move or rotate in the XY plane when they are bonded together. The central axis of the positioning post (5) is strictly perpendicular to the substrate plane.

[0056] In addition, a first positioning hole and a first positioning post can be provided on the first substrate, and a second positioning hole and a second positioning post can be provided on the second substrate. The inner diameter of the first positioning hole and the outer diameter of the second positioning post adopt an interference fit or a transition fit to realize the mutual engagement of the first positioning hole and the second positioning post. Similarly, the second positioning hole and the first positioning post are the same as above.

[0057] like Figure 1As shown, during bonding, the first substrate (1) and the lower substrate (2) are precisely aligned with the positioning holes by the positioning pins (5) and then pressed together. At this time, the first channel (11) on the lower surface of the first substrate (1) and the second channel (21) on the upper surface of the second substrate (2) are spatially separated vertically. The first opening (13) and the second opening (23) face each other and overlap, forming a complete channel connection (6), thereby realizing fluid communication between the upper first channel (11) and the lower second channel (21).

[0058] The working principle and usage of this utility model are as follows:

[0059] Droplet loading: A continuous phase (e.g., fluorinated oil containing a surfactant) is injected through the first sample port (3) to fill the first channel (11). Then, an aqueous droplet containing the sample to be encapsulated (e.g., cells, reagents) (typically generated by an upstream droplet generation chip) is also injected through the first sample port (3). Driven by the oil, the droplet enters the serpentine path of the first channel (11).

[0060] Droplet storage and culture: Droplets sequentially fill each bend of the first channel (11). Due to the confinement of the channel, the droplets are separated by the oil phase, allowing them to be stored independently and stably within the channel. At this point, the entire chip can be observed under a microscope or placed in a cell culture incubator for long-term culture.

[0061] Droplet Transfer and Export: When droplets need to be exported for subsequent analysis, a negative pressure can be applied from the second sample port (4) or a positive pressure can be applied from the first sample port (3). The droplet will flow along the first channel (11) and reach the channel junction (6). Driven by pressure, the droplet first smoothly changes its flow direction along the first inclined guide surface (12), moves downward through the first opening (13) and the second opening (23), then enters the second channel (21) along the second inclined guide surface (22), and finally flows out from the second sample port (4) into the downstream detection or sorting chip. The entire process is controlled and stable, and the integrity is greatly guaranteed.

[0062] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all modifications and variations falling within the scope of the present invention.

[0063] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

[0064] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A microfluidic droplet storage chip, characterized in that, The microfluidic droplet storage chip includes: a first substrate and a second substrate; The first substrate and the second substrate are bonded together; A first channel is provided on the lower surface of the first substrate; The upper surface of the second substrate is provided with a second channel; The first channel and the second channel are used to store droplets; The lower surface of the first substrate and the upper surface of the second substrate are connected vertically at the junction formed by the first channel and the second channel.

2. The microfluidic droplet storage chip according to claim 1, characterized in that, The end of the junction between the first channel and the second channel is a first inclined guide surface, and the end of the junction between the second channel and the second channel is a second inclined guide surface; The first inclined guide surface and the first channel form a first opening, and the second inclined guide surface and the second channel form a second opening, and the first opening and the second opening are connected.

3. The microfluidic droplet storage chip according to claim 2, characterized in that, The first inclined guide surface and the second inclined guide surface form an angle greater than 0 degrees and less than 90 degrees with the horizontal plane where the first substrate and / or the second substrate are located.

4. The microfluidic droplet storage chip according to claim 1, characterized in that, Both the first channel and the second channel are multiple curved serpentine channel structures, which are formed by connecting multiple arc-shaped units in sequence to form a meandering channel.

5. The microfluidic droplet storage chip according to claim 4, characterized in that, The first channel and the second channel occupy the maximum area of ​​the bonding surface of the first substrate and the second substrate.

6. The microfluidic droplet storage chip according to claim 1, characterized in that, One end of the first channel is connected to the second channel, and the other end is the first sample inlet.

7. The microfluidic droplet storage chip according to claim 1, characterized in that, One end of the second channel is connected to the first channel, and the other end is the second sample port.

8. The microfluidic droplet storage chip according to claim 1, characterized in that, The first substrate and the second substrate are provided with positioning posts that penetrate through or are formed by themselves, and the central axis of the positioning posts is perpendicular to the plane of the first substrate and / or the second substrate. The positioning post is used to fix and align the first substrate and the second substrate.

9. The microfluidic droplet storage chip according to claim 8, characterized in that, The positioning posts are located on opposite sides of the first substrate and the second substrate.

10. The microfluidic droplet storage chip according to claim 1, characterized in that, The first substrate is provided with at least one positioning post and / or at least one positioning hole, and the second substrate is provided with at least one positioning post and / or at least one positioning hole, wherein the positioning post and the positioning hole are interlocked with each other.

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