A microfluidic chip

Abstract

The utility model provides a kind of microfluidic chip belongs to microfluidic chip technical field. Including substrate, the upper surface of the substrate stable installation middle layer electric board, the upper surface of the middle layer electric board stable installation receiving electric board, and in the inside embedded micro flow channel of receiving electric board, the upper of the micro flow channel is also provided with cover. By using superimposed installation in substrate, middle layer electric board and receiving electric board, multilayer structure can resist complex environment, improve use effect, and in the inside embedded micro flow channel of receiving electric board, using micro flow channel can accurately flow the liquid to be detected to detection area, it is convenient to detect antibiotic in the liquid to be detected, improve detection accuracy.

Description

Technical Field

[0001] This utility model relates to the field of microfluidic chip technology, and more specifically, to a microfluidic chip. Background Technology

[0002] The widespread use of antibiotics in medicine, animal husbandry, and agriculture, while effectively combating bacterial infections, has also brought about a series of problems such as antibiotic residues and bacterial resistance. Therefore, rapid and accurate detection of antibiotics in food, medicine, and the environment, as well as efficient screening and efficacy evaluation of antibiotics, have become crucial for safeguarding public health and maintaining ecological balance.

[0003] However, existing microfluidic chips still have significant shortcomings in antibiotic-related applications. For example, when dripping liquid, it is impossible to accurately control the sample volume and distribution. The liquid dripped into the chip will flow everywhere and cannot flow in a concentrated or precise manner. In addition to the problem of flowing everywhere, when too much liquid is dripped, it is easy to overflow and cause waste. When too little liquid is dripped, it will affect the accuracy of liquid detection. Utility Model Content

[0004] To overcome the above deficiencies, this utility model provides a microfluidic chip that overcomes or at least partially solves the above technical problems.

[0005] This utility model is implemented as follows: This utility model provides a microfluidic chip, including a substrate, an intermediate layer circuit board is stably mounted on the upper surface of the substrate, a receiving circuit board is stably mounted on the upper surface of the intermediate layer circuit board, and a microfluidic channel is embedded inside the receiving circuit board. A cover plate is also provided above the microfluidic channel.

[0006] In a preferred embodiment, mounting holes are provided at the four corners of the upper surface of the substrate.

[0007] In a preferred embodiment, the substrate and the intermediate layer circuit board are directly connected via a first lead, and the receiving circuit board and the intermediate layer circuit board are connected via a second lead.

[0008] In a preferred embodiment, a temperature sensor is mounted on the upper surface of the microchannel.

[0009] In a preferred embodiment, the liquid inlet end of the microchannel penetrates the interior of the cover plate and is embedded within the interior of the cover plate.

[0010] In a preferred embodiment, a reinforcing member is also fixedly mounted on the bottom of the substrate.

[0011] In a preferred embodiment, the inner surface of the cover plate is stably connected to the coated substrate.

[0012] In a preferred embodiment, the cover plate covers the substrate, and the receiving plate is positioned inside the cover plate.

[0013] The microfluidic chip provided by this utility model has the following beneficial effects: 1. By using a stacked installation of the substrate, intermediate layer circuit board and receiving circuit board, the multi-layer structure can withstand complex environments and improve the performance. Furthermore, the microchannels embedded inside the receiving circuit board can accurately flow the liquid to be tested to the detection area, which is convenient for detecting antibiotics in the liquid and improves the accuracy of the detection.

[0014] 2. By installing reinforcing members at the bottom of the substrate, the substrate can be prevented from deforming due to temperature or pressure inside the microchannels, thereby improving the substrate strength, resistance to bending deformation, and flatness. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram showing the location of the temperature sensor of this utility model; Figure 3 This is an exploded view of the inner structure of the cover plate of this utility model; Figure 4 This is a schematic diagram of the bottom structure of the substrate of this utility model.

[0017] In the figure: 1. Substrate; 2. Intermediate layer circuit board; 3. Receiving circuit board; 4. Microchannel; 5. Cover plate; 6. Mounting hole; 7. First lead; 8. Second lead; 9. Temperature sensor; 10. Reinforcing member; 11. Coated substrate. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] Example Reference Figures 1-4 This utility model provides a technical solution: a microfluidic chip, including a substrate 1, which serves as the bottom support of the chip. Specifically, the substrate 1 must be mechanically stable, chemically inert, and insulating. Materials such as silicon wafers or polymethyl methacrylate can be selected. An intermediate layer electrode 2 is stably mounted on the upper surface of the substrate 1, and a receiving electrode 3 is stably mounted on the upper surface of the intermediate layer electrode 2. The intermediate layer electrode 2 and the receiving electrode 3 serve as an intermediate layer, possessing good conductivity and chemical stability. Commonly used materials include metal thin films, such as copper, or conductive polymers. For example, polypyrrole, and a microchannel 4 is embedded inside the receiving plate 3. A cover plate 5 is also provided above the microchannel 4. In this device, the intermediate layer plate 2 is stably connected to the substrate 1 by thermo-press bonding to ensure that the electrodes on the intermediate layer plate 2 and the interfaces on the substrate 1 are accurately connected to avoid signal distortion caused by poor contact. The receiving plate 3 is made of materials such as PDMS and PMMA. As the carrier of the microchannel 4, the thickness of the receiving plate 3 needs to match the depth of the microchannel 4 to ensure the stability of the microchannel 4 structure and prevent damage due to liquid pressure.

[0020] The diameter of the microchannel 4 is set to 10μm-50μm. The microchannel 4 is a single channel, which is arranged in a serpentine shape on the receiving plate 3. The two ends of the microchannel 4 are respectively set as the liquid inlet and the liquid outlet. When in use, the liquid to be tested enters from the liquid inlet and exits from the liquid outlet.

[0021] In a preferred embodiment, mounting holes 6 are respectively provided at the four corners of the upper surface of the substrate 1. By providing mounting holes 6 on the substrate 1, these mounting holes 6 are suitable for mounting the substrate 1, which can be stably connected to the external mounting equipment by tightening screws. The diameter of the mounting holes 6 is set to 1mm-3mm, the hole depth is the same as the thickness of the substrate 1, and the center of the mounting hole 6 is 2cm-3cm away from the edge of the four corners of the substrate 1. The process of opening the mounting holes 6 on the substrate 1 adopts the laser drilling process, and the hole wall can be plated with a thin metal, such as nickel, to enhance wear resistance.

[0022] In a preferred embodiment, the substrate 1 and the intermediate layer electrode 2 are directly connected by a first lead 7, and the receiving electrode 3 and the intermediate layer electrode 2 are connected by a second lead 8. The first lead 7 is made of a highly conductive metal, such as gold and copper, and is formed into a thin film lead by sputtering or vapor deposition. The width of the first lead 7 and the second lead 8 is set to 50μm-90μm and the thickness is 20nm-40nm. The first lead 7 and the second lead 8 are arranged along the edge of the upper surface of the substrate 1, avoiding the position of the four corner mounting holes 6.

[0023] In a preferred embodiment, a temperature sensor 9 is installed on the upper surface of the microchannel 4. The temperature sensor 9 ensures the stability of the reaction conditions during antibiotic detection. The temperature sensor 9 covers the upper surface of the microchannel 4 and captures the liquid temperature in real time. The temperature sensor 9 is bonded to the upper surface of the microchannel 4 with thermally conductive silicone. The thickness of the silicone is controlled between 60μm and 100μm to ensure good thermal conductivity and thermal resistance <0.1℃・cm² / W. It can also buffer the thermal stress between the temperature sensor 9 and the microchannel 4 and prevent the structure from falling off due to temperature changes.

[0024] Considering the potential presence of chemical reagents such as antibiotics and buffer solutions in the liquid within the microchannel 4, as well as the microscale characteristics of the detection environment, temperature sensors 9 typically employ miniature thin-film sensors, such as platinum resistance sensors (Pt1000) or thermocouples like type K thermocouples. Platinum resistance sensors are fabricated on ceramic substrates using a sputtering process, allowing for a size reduction to 0.3mm × 0.3mm with an accuracy of ±0.1℃, suitable for monitoring the common temperature range of bacterial culture at 30-40℃. Thermocouples, on the other hand, consist of two different metal wires, such as copper-constantan, encapsulated within a polyimide film, resulting in a faster response time constant <0.5s. This allows them to capture instantaneous temperature fluctuations during rapid mixing of the liquid within the microchannel 4, while also exhibiting excellent chemical corrosion resistance and adaptability to liquid environments ranging from pH 2 to 12.

[0025] The liquid inlet end of the microchannel 4 penetrates the interior of the cover plate 5 and is embedded inside the cover plate 5. The liquid inlet end of the microchannel 4 is vertically positioned to penetrate into the interior of the cover plate 5, forming a dripping area on the cover plate 5. The liquid to be tested is dripped into the dripping area and smoothly enters the interior of the microchannel 4. After the liquid inlet end of the microchannel 4 penetrates into the interior of the cover plate 5, a 1μm-2μm sealing material, such as a sealing gasket, is applied at the connection between the two. The sealing gasket is installed at the connection between the two by adhesive method to improve the sealing performance.

[0026] A reinforcing member 10 is fixedly installed at the bottom of the substrate 1. The reinforcing member 10 is made of lightweight high-strength alloy or carbon fiber composite material. These materials have both rigidity and toughness, which can buffer the damage to the substrate 1 caused by external impact. Moreover, the thickness of the reinforcing member 10 is selected from 0.1mm to 0.3mm. The rigidity of the reinforcing member 10 is used to suppress the bending deformation of the substrate 1 under temperature changes or external forces. For example, the pressure when liquid enters the microchannel 4 can cause the middle of the substrate 1 to bulge. At this time, the reinforcing member 10 can prevent this from happening. In terms of structural design, the reinforcing member 10 does not completely cover the bottom of the substrate 1, but adopts a frame type. The frame-type reinforcing member 10 will form a closed frame around the bottom edge of the substrate 1. A hollow area is reserved in the middle of the reinforcing member 10 to avoid the circuit interface or heat sink integrated at the bottom of the substrate 1. The reinforcing member 10 is bonded to the bottom of the substrate 1 with epoxy adhesive or connected with micro screws, so that the reinforcing member 10 can be stably installed at the bottom of the substrate 1.

[0027] The inner side of the cover plate 5 is stably connected to the coating substrate 11, which is in direct contact with the outer surface of the chip and is used to assist in heat dissipation of the chip. The commonly used material is polyimide film, with a temperature resistance range of -20-200℃, which is suitable for scenarios requiring high-temperature reactions. Thermal grease is applied to the connection surface of the coating substrate 11. The adhesiveness of the thermal grease is used to adhere the coating substrate 11 to the chip, which can stably connect the coating substrate 11 and the chip.

[0028] The cover plate 5 is placed on the substrate 1, and the receiving plate 3 is placed inside the cover plate 5. The device covers the substrate 1 with the cover plate 5, and the edge of the cover plate 5 is aligned with the edge of the substrate 1. The cover plate 5 and the substrate 1 are bonded with hot melt adhesive, which can stably connect the cover plate 5 and the substrate 1. The cover plate 5 provides initial protection for the receiving plate 3.

[0029] Specifically, the working process or working principle of a microfluidic chip is as follows: Based on the fact that existing microfluidic chips still have significant shortcomings in antibiotic-related applications, such as the inability to accurately control the sample volume and distribution when dripping liquid, the liquid will flow around in different places when dripped into the chip, and cannot flow in a concentrated or precise manner. In addition to the problem of flowing around in different places when dripping liquid, there is also the problem that if too much liquid is dripped, it will easily overflow and cause waste, and if too little liquid is dripped, it will affect the accuracy of liquid detection. Therefore, this device was designed. The microfluidic chip in this device adopts an integrated structure, and a microchannel 4 is embedded inside the receiving plate 3. The function of the microchannel 4 is to drop the liquid to be detected and processed into the microchannel 4, so that the liquid can flow to the position of the electroreaction zone, which facilitates the subsequent detection of antibiotic components in the liquid. The multi-layer structure is resistant to complex environments.

[0030] Specifically, substrate 1 is used as the bottom layer, and intermediate layer circuit board 2, receiving circuit board 3 and chip are mounted on substrate 1. Intermediate layer circuit board 2 is fixedly mounted on the upper surface of substrate 1, and receiving circuit board 3 is stably mounted on intermediate layer circuit board 2. Microchannel 4 is embedded inside receiving circuit board 3, but the outer surface of microchannel 4 extends out of receiving circuit board 3. An electrochemical reaction zone is set at the bend of microchannel 4. The liquid to be tested is dripped into the interior of microchannel 4 and flows inside microchannel 4. When the liquid flows to the position of electrochemical reaction zone, an electrochemical signal is generated. This signal can be electrically connected to the electrochemical reaction zone through external detection equipment, and the monitored data can be displayed on an external computer. Antibiotic components in the liquid can be detected. Finally, the waste liquid is discharged from the outlet of microchannel 4.

[0031] This device has a cover plate 5 on the receiving board 3, and a dripping space is constructed on the cover plate 5. This space is connected to the interior of the microchannel 4, and is used to drip liquid from the dripping space into the interior of the microchannel 4. This device also has a temperature sensor 9 on the outside of the microchannel 4, which is used to detect the temperature of the chip.

[0032] This device uses a reinforcing member 10 installed on the back of the substrate 1. The reinforcing member 10 can shape the substrate 1, enhance its strength, resist bending deformation and improve its flatness, so as to avoid bending and clogging of the microchannel 4.

Claims

1. A microfluidic chip, comprising a substrate (1), characterized in that, An intermediate layer plate (2) is stably mounted on the upper surface of the substrate (1), a receiving plate (3) is stably mounted on the upper surface of the intermediate layer plate (2), and a microchannel (4) is embedded inside the receiving plate (3). A cover plate (5) is also provided above the microchannel (4).

2. A microfluidic chip according to claim 1, characterized in that, Mounting holes (6) are respectively provided at the four corners of the upper surface of the substrate (1).

3. A microfluidic chip according to claim 2, characterized in that, The substrate (1) and the intermediate layer circuit board (2) are directly connected by the first lead (7), and the receiving circuit board (3) and the intermediate layer circuit board (2) are connected by the second lead (8).

4. A microfluidic chip according to claim 3, characterized in that, A temperature sensor (9) is installed on the upper surface of the microchannel (4).

5. A microfluidic chip according to claim 4, characterized in that, The liquid inlet end of the microchannel (4) penetrates the interior of the cover plate (5) and the liquid inlet end of the microchannel (4) is embedded inside the cover plate (5).

6. A microfluidic chip according to claim 5, characterized in that, A reinforcing member (10) is also fixedly installed at the bottom of the substrate (1).

7. A microfluidic chip according to claim 6, characterized in that, The inner side of the cover plate (5) is stably connected to the coated substrate (11).

8. A microfluidic chip according to claim 7, characterized in that, The cover plate (5) covers the substrate (1) and the receiving plate (3) is placed inside the cover plate (5).

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