Electronic microarray chip detector liquid path system and control method

Abstract

The invention discloses an electronic microarray chip detector liquid path system and a control method, and belongs to the technical field of biological detection.The electronic microarray chip detector liquid path system comprises a four-channel-structure liquid distribution needle set, a liquid distribution needle set and a liquid distribution needle set, four channels of the rotary valve with the ten-channel structure are connected with the reagent needle, and the reagent needle needs to suck an air column larger than or equal to 2 mm after sucking a reagent so as to suck another reagent, so that physical isolation is realized; according to the confluence plate assembly adopting laser bonding, a micro-channel has a rectangular cross section (0.5 * 0.5 mm, the surface roughness Ra is less than or equal to 1.6 mu m), and the dead volume is less than or equal to 12 mu L; the temperature control unit is integrated on the bus board assembly and comprises an FPC (Flexible Printed Circuit) heating sheet and a temperature sensor; and the injection pump is linked with the flow sensor. Through three-stage cooperative control of a rotary valve, a confluence plate assembly and an injection pump, flow channel design and process optimization are combined, and accurate control over micro-upgrading liquid is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of biological detection, and relates to a liquid path system of an electronic microarray chip detector and a control method. Background Art

[0002] As a key device in the field of biological testing, electronic microarray chip detectors play an important role in disease diagnosis and genetic research. Their fluidic systems are the core component that ensures accurate and efficient testing, but the system currently faces many challenges that need to be addressed.

[0003] In terms of detection accuracy, the use of multiple reagents sharing the same pipeline leads to serious cross-contamination. For example, residual ions in SSC will interfere with the detection of NaCl electrical signals, affecting the accuracy of the results. The flow channels of traditional manifolds are rough, and the dead volume is as high as 120μL, resulting in low utilization of trace reagents and a waste of resources. At the same time, the pulsation of the injection pump causes flow fluctuations of more than ±10%, and temperature fluctuations of ±2°C cause electrical signal drifts of ±15mV. The insufficient stability of the system further reduces the reliability of the detection; the complex pipeline connections lead to a high risk of bubble retention, and bubbles will affect the flow of reagents and detection signals, thereby interfering with the test results. In terms of operational convenience, chip replacement requires resealing the pipeline, which takes more than 5 minutes each time, resulting in low detection efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a liquid circuit system and control method for an electronic microarray chip detector, which realizes precise manipulation of microliter-level liquids through three-level coordinated control of a rotary valve, a manifold assembly, and a syringe pump, combined with flow channel design and process optimization.

[0005] The purpose of the present invention is achieved through the following technical solutions: An electronic microarray chip detector liquid path system, comprising: The dispensing needle assembly with a four-channel structure has an inner surface Ra ≤ 0.1 μm; The rotary valve has at least four channels (actually a ten-channel structure), four of which are connected to the reagent needle. After the reagent needle aspirates the reagent, it needs to aspirate an air column of ≥2mm before aspirating another reagent to achieve physical isolation; The laser-bonded manifold assembly has a rectangular microchannel cross-section (0.5 × 0.5 mm, surface roughness Ra ≤ 1.6 μm) and a dead volume ≤ 12 μL. Temperature control unit integrated into the manifold assembly, including FPC heater and temperature sensor; The syringe pump is linked to the flow sensor.

[0006] As a further improvement of an embodiment of the present invention, the dispensing needle assembly includes a spring buffer structure and a needle adjustment plate, and the needle body is made of passivated 316L stainless steel.

[0007] As a further improvement of one embodiment of the present invention, the dispensing needle group includes 4 independent reagent needles, the outer surface of the reagent needle is provided with a hydrophobic coating, the inner surface is polished, and the inner roughness Ra of the reagent needle is less than 0.1.

[0008] As a further improvement of one embodiment of the present invention, the manifold assembly is formed by laser bonding of a double-layer PC board, the upper board is provided with a liquid path interface and a microchannel, and the lower board is a laser welded cover plate; the total flow channel volume of the manifold assembly is ≤12μL.

[0009] As a further improvement of an embodiment of the present invention, the temperature control unit stabilizes the temperature of the reagent at 37±0.5°C, and the temperature fluctuation rate is ≤0.3°C / s.

[0010] As a further improvement of one embodiment of the present invention, it also includes a motor-driven chip pressing mechanism to achieve automatic pressing / separation of the chip and the sealing ring of the busbar assembly, and the replacement time is less than 10 seconds.

[0011] As a further improvement of one embodiment of the present invention, the main channel of the rotary valve is connected to the manifold assembly via a PTFE tube (ID 0.5 mm), and the spare channel supports calibration liquid access, waste liquid diversion and new reagent integration.

[0012] As a further improvement of an embodiment of the present invention, the manifold assembly has a built-in three-way solenoid valve to realize the chip flow channel bypass function.

[0013] A liquid circuit control method, applied to the liquid circuit system of the electronic microarray chip detector, is characterized by comprising: Step 1: Turn on the heater to stabilize the temperature of the manifold assembly at 37±0.5℃; Step 2: Clean the flow channel at a flow rate of 150 μL / s. Switch channels when the temperature fluctuation is ≤0.3°C / s. A rotary valve is used to physically isolate the different reagent channels. After the reagent switch, a graded flushing process of SSC solution → water → NaCl is performed. Step 3: Electrical signal acquisition must simultaneously meet the following requirements: flow rate fluctuation ≤ ±2% for 5s, temperature fluctuation ≤ ±0.5°C, and pressure change rate ≤ 0.01 kPa / s.

[0014] As a further improvement of one embodiment of the present invention, the syringe pump extracts the reagent in a negative pressure manner, and the single aspiration volume does not exceed the single stroke volume of the syringe pump.

[0015] The above technical solution has the following beneficial effects: the rotary valve switching is used to clean the pipeline after each use of the reagent, effectively solving the cross contamination caused by the shared pipeline; the high-precision syringe pump is used to extract the reagent under negative pressure, and the internal volume of the instrument is much lower than the suction range of the syringe pump, ensuring that each time the reagent is drawn up, it is within the suction range of the syringe pump, completely avoiding the pulsation interference caused by the switching of the syringe pump; the manifold assembly is precisely processed and its flow channel is polished, Ra < 1.6μm, reducing the residue and liquid resistance, and at the same time the instrument solenoid valve is concentrated on the manifold assembly, and the liquid is transported through the microchannel switching; the chip and the manifold assembly use a motor to control the seal, and the chip in and out of the compartment is controlled by a motor, which greatly reduces the time to replace the chip, and the chip replacement time is < 10s / time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0017] The structures, proportions, sizes, etc. illustrated in this specification are intended only to complement the contents disclosed herein and to facilitate understanding and reading by persons familiar with the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall still fall within the scope of the technical contents disclosed herein.

[0018] Figure 1 This is a schematic diagram of the liquid circuit principle provided by the present invention.

[0019] Figure 2 Schematic diagram of the combination of the dispensing needle group and the driving mechanism in the present invention.

[0020] Figure 3 This is a schematic structural diagram of the dispensing needle assembly provided by the present invention.

[0021] Figure 4 for Figure 3 Schematic diagram of the cross section along AA.

[0022] Figure 5 This is a schematic diagram of the first state of the busbar assembly provided by the present invention.

[0023] Figure 6 This is a schematic diagram of the second state of the busbar assembly provided by the present invention.

[0024] Figure 7This is a schematic diagram of the distribution of microchannels on the manifold provided by the present invention.

[0025] In the picture: 1. Dispensing needle set; 11. Adjust the needle plate; 12. Reagent needle; 13. Reagent needle welding threaded parts; 14. Spring; 15. Spring connector; 16. Pipet needle seat; 2. Rotary valve; 3. Manifold assembly; 31. Manifold; 32. Rear cover; 33. Busbar bonding cover; 34. Soaking copper plate; 35. FPC heating sheet; 36. Rubber sheet; 37. Large three-way solenoid valve; 38. Small three-way solenoid valve; 39. Chip cover sealing gasket; 310, electrode sealing rubber column; 311, electrode; 312, 1 / 4-28 threaded connector; 313, 6-40 threaded joint; 4. Syringe pump; 5. Valve; 6. Liquid pump. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0028] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0029] Explanation of terms:

[0030] See also Figure 1 As shown, a liquid path system of an electronic microarray chip detector includes: The dispensing needle assembly 1 of the four-channel structure has an inner surface Ra ≤ 0.1 μm; The rotary valve 2 has a ten-channel structure, in which four channels are connected to the reagent needle. After the reagent needle aspirates reagent 1, it needs to aspirate an air column ≥ 2mm before aspirating reagent 2, effectively preventing cross contamination and achieving physical isolation; The laser-bonded manifold assembly 3 has a rectangular microchannel cross-section (0.5×0.5mm, surface roughness Ra≤1.6μm) and a dead volume ≤12μL, greatly improving the utilization rate of trace reagents. The temperature control unit integrated in the manifold assembly 3, including the FPC heater (referred to as the heater) and the temperature sensor (PT1000), can accurately control the temperature of the fluid system; The syringe pump 4 is linked to the flow sensor.

[0031] Specifically, dispensing needle assembly 1 contains four independent reagent needles, which are inserted into four reagent bottles containing NaCl solution, 0.1xSSC solution, 2xSSC solution, and water. The reagent needles are connected to the four channels of rotary valve 2 via pipes. Then, pipes are led from the main channel of rotary valve 2 to manifold assembly 3. Microchannels in manifold assembly 3 transport liquid to the biochip. The inlet and outlet of manifold assembly 3 are connected and sealed with the inlet and outlet of the chip. The liquid is then aspirated from manifold assembly 3 to syringe pump 4. Finally, the waste liquid is discharged through the discharge port of syringe pump 4. (When syringe pump 4 requires maintenance, valve 5 is opened and liquid pump 6 is used to drain the waste liquid into the waste liquid bottle.)

[0032] Instrument fluid flow: 1. Fill the entire pipeline with NaCl and monitor the initial electrical signal; 2. Use 2xSSC solution and 0.1xSSC solution to clean the manifold assembly and chip in turn; 3. Refill the chip with NaCl and measure the electrical signal; 4. The algorithm gives the result.

[0033] In this embodiment, the rotary valve 2 has four channels enabled, and the reserved channels can be used for: calibration liquid access, waste liquid diversion, and new reagent integration.

[0034] Specifically, if Figure 2-Figure 4 As shown, the dispensing needle assembly 1 includes a needle adjustment plate 11, and a reagent needle 12 is vertically inserted into the needle adjustment plate 11 and fixed by a spring buffer structure. In this embodiment, two needle adjustment plates 11 are placed on the pipetting needle seat 16 in an orderly manner.

[0035] In actual operation, when the reagent needle 12 touches the bottom of the container, the spring buffer structure can play a buffering role, effectively preventing the reagent needle 12 from breaking or bending. In addition, by moving the needle adjustment plate 11, the position of the reagent needle 12 can be flexibly adjusted to meet the needs of different detection scenarios.

[0036] The spring buffer structure includes a spring connector 15, a reagent needle welding threaded part 13 and a spring 14. The specific installation method is: first, the reagent needle 12 is vertically inserted into the reagent needle welding threaded part 13, then the spring 14 is sleeved on the outside of the reagent needle welding threaded part 13, and then the two are placed from bottom to top in the mounting hole of the needle adjustment plate 11, and finally, the spring connector 15 is used to fix the reagent needle welding threaded part 13 from the top of the needle adjustment plate 11. At this time, one end of the spring 14 abuts on the needle adjustment plate 11 outside the mounting hole, and the other end abuts on the reagent needle welding threaded part 13. In the unstressed state, the combination of the spring connector 15 and the reagent needle welding threaded part 13 sinks under the action of the spring 14; when the reagent needle 12 touches the bottom and is stressed, the combination moves upward as a whole, thereby playing a good buffering role for the reagent needle 12. The upper end of the reagent needle 12 is connected to the rotary valve 2 through a PTFE tube.

[0037] In this embodiment, the reagent needle 12 is made of passivated 316L stainless steel, which has excellent corrosion resistance and chemical stability, meeting the requirements of contact with multiple reagents during the detection process. Its inner diameter is set to 0.5mm, which ensures smooth passage of reagents while facilitating precise control of reagent flow. The outer surface is coated with a hydrophobic coating to effectively reduce reagent residue and prevent cross contamination. The inner surface is polished to an internal roughness Ra of less than 0.1, reducing liquid flow resistance.

[0038] The rotary valve 2 with a ten-channel structure in this embodiment plays a key role. Four of the channels are connected to reagent needles for the precise introduction of different reagents; the other six channels are reserved for expansion, leaving ample space for the subsequent addition of detection reagent types or functions. The main channel outlet is connected to the manifold assembly 3 via a PTFE tube with an ID of 0.5 mm. The PTFE tube can also be replaced with other pipes of the same specification that are resistant to chemical corrosion and have good sealing properties. This "1 main channel + multiple backup channels" architectural design allows for flexible expansion of reagent types when facing different detection needs, without the need for large-scale changes to the overall liquid circuit system, thereby improving the versatility and adaptability of the system.

[0039] Combine Figure 5 、 Figure 6As shown, the laser-bonded busbar assembly 3 is formed integrally using a double-layer PC board through a laser bonding process. The upper plate, namely the busbar 31, is provided with a liquid path interface and a microchannel. The cross-section of the microchannel is a rectangular structure of 0.5mm×0.5mm, which can also be adjusted to other regular or irregular shapes according to actual needs; the lower plate is the back cover 32, which serves as a laser welding cover to seal. Between the busbar 31 and the back cover 32, a busbar bonding cover 33, a heat-saturating copper plate 34, an FPC heating plate 35, and a rubber sheet 36 are arranged in sequence from top to bottom. In addition to using 1 / 4-28 threaded joints 312 and 6-40 threaded joints 313, the locking method of the busbar 31 and the back cover 32 can also be replaced with threaded joints of other specifications. A large three-way solenoid valve 37 and a small three-way solenoid valve 38 are located on the outside of the manifold 31. Four small three-way solenoid valves 38 are reserved on the manifold to facilitate the addition of new reagents. The large three-way solenoid valves 37 provide a bypass function for the chip flow channel. Furthermore, the FPC heater 35 includes a built-in temperature sensor that monitors the temperature within the microchannel in real time, ensuring stable system operation.

[0040] A chip cover gasket 39 is specially provided on one side of the busbar 31. This gasket can also be made of a material with good sealing and elasticity, such as rubber or silicone, to prevent liquid leakage. At the same time, an electrode 311 is also inserted into the busbar 31. The shape of the electrode 311 can be cylindrical to accommodate different electrical connection requirements. To secure the electrode 311, an electrode sealing rubber column 310 is provided on the busbar 31 to firmly fix the electrode 311 to the busbar 31 and ensure the reliability of the electrical connection.

[0041] The manifold assembly 3 and the chip's liquid inlet and outlet ports are equipped with silicone seals, which can be replaced with seals made of other corrosion-resistant, airtight materials such as fluororubber to ensure a good seal. Furthermore, a motor-driven chip crimping mechanism, which can be flexibly designed with various drive mechanisms, such as screw drive and rack-and-pinion transmission, enables automatic, precise pressing and rapid separation of the chip and manifold assembly seals. Chip replacement time is strictly controlled to less than 10 seconds, significantly improving operational efficiency.

[0042] The FPC heater 35 incorporates a high-precision temperature sensor, which together form a closed-loop temperature control system. This system maintains the reagent temperature within a precise range of 37±0.5°C, effectively reducing electrical signal drift caused by temperature fluctuations from ±15mV to ±2mV. Combined with precise flow rate control, this significantly improves the signal-to-noise ratio to 45dB, compared to 32dB with traditional solutions, significantly enhancing detection accuracy and reliability.

[0043] like Figure 7 The microchannel structure on the manifold shown is connected to the rotary valve 2 and tested. The flow rate is measured as follows:

[0044] It can be seen that the total amount of reagent in the manifold is only 11.27 μL, which greatly reduces reagent waste. The total flow channel volume of 11.27 μL refers to the flow channel volume, and the actual dead volume calculation includes the liquid replacement rate.

[0045] The comparison between the manifold microchannel design in this embodiment and the traditional method is as follows:

[0046] The temperature-electrical signal correlation table in this embodiment is as follows:

[0047] It can be seen that the temperature fluctuation of the liquid circuit system provided by the present invention is small, and the electrical signal drift performance is significantly improved.

[0048] A liquid circuit control method, applied to the liquid circuit system of the electronic microarray chip detector, is characterized by comprising: Step 1: Start the FPC heater 35 and use its built-in temperature sensor to establish a closed-loop temperature control to stabilize the temperature of the manifold assembly within the set range of 37±0.5°C; Step 2: Clean the flow channel at a flow rate of 150 μL / s. Continuously monitor temperature fluctuations during the cleaning process. When the temperature fluctuation is ≤0.3°C / s, physically isolate the different reagent channels using a rotary valve and switch channels. After the reagent switch, perform a graded flushing process of SSC solution → water → NaCl to ensure the flow channel is clean. Step 3: When collecting electrical signals, the following conditions must be met simultaneously: flow rate fluctuation ≤±2% and lasting 5s, temperature fluctuation ≤±0.5℃, and pressure change rate ≤0.01kPa / s to ensure the accuracy and stability of the collected data.

[0049] In this embodiment, the syringe pump 4 operates by extracting the reagent under negative pressure. The syringe pump can also be replaced with a peristaltic pump or other pump structure that can achieve negative pressure extraction. At the same time, to ensure the stability and accuracy of the extraction process, the amount of reagent drawn in a single time is strictly controlled to not exceed the single-stroke volume of the syringe pump. The mapping relationship between the syringe pump operating parameters and the electrical signal acquisition is as follows:

[0050] The advantages provided by the present invention can be summarized as follows:

[0051] It can be seen from this that the present invention has achieved the following effects: 1. Reduce the dead volume of the instrument; 2. Reduce reagent consumption; 3. Improved signal-to-noise ratio of electrical signals; 4. Improve chip analysis consistency; 5. Flow rate stability is improved. The following data are measured using the weighing method. The measured data are shown in the table below.

[0052] The present invention adopts rotary valve switching, which can clean the pipeline after each use of the reagent, effectively solving the cross contamination caused by shared pipelines; a high-precision syringe pump is used to extract reagents under negative pressure, and the internal volume of the instrument is much lower than the suction range of the syringe pump, ensuring that each time the reagent is drawn up, it is within a suction range of the syringe pump, completely avoiding the pulsation interference caused by the switching of the syringe pump; the manifold assembly is precisely processed and its flow channel is polished, Ra < 1.6μm, reducing the residue and liquid resistance, and at the same time the instrument solenoid valve is concentrated on the manifold assembly, and the liquid is transported through the microchannel switching; the chip and the manifold assembly are controlled by a motor to lift and lower to control the seal, and the chip in and out of the compartment is controlled by a motor, which greatly reduces the time for replacing the chip, and the chip replacement time is <10s / time.

[0053] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of 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 the present invention.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0055] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0056] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An electronic microarray chip detector liquid path system, characterized in that: include: The dispensing needle assembly with a four-channel structure has an inner surface Ra ≤ 0.1 μm; The rotary valve has at least four channels, four of which are connected to the reagent needle. After the reagent needle aspirates the reagent, it needs to aspirate an air column ≥2mm before aspirating another reagent to achieve physical isolation; The laser-bonded manifold assembly has a rectangular cross-section microchannel with a surface roughness of Ra ≤ 1.6 μm and a dead volume of ≤ 12 μL. Temperature control unit integrated into the manifold assembly, including FPC heater and temperature sensor; The syringe pump is linked to the flow sensor.

2. The liquid path system of the electronic microarray chip detector according to claim 1, characterized in that: The dispensing needle assembly includes a spring buffer structure and a needle adjustment plate, and the needle body is made of passivated 316L stainless steel.

3. The liquid path system of the electronic microarray chip detector according to claim 2, characterized in that: The dispensing needle group includes 4 independent reagent needles, the outer surfaces of the reagent needles are provided with a hydrophobic coating, the inner surfaces are polished, and the inner roughness Ra of the reagent needles is less than 0.

1.

4. The liquid path system of the electronic microarray chip detector according to claim 1, characterized in that: The manifold assembly is formed by laser bonding of double-layer PC boards, the upper board is provided with a liquid path interface and a microchannel, and the lower board is a laser welded cover board; the total flow channel volume of the manifold assembly is ≤12μL.

5. The liquid path system of the electronic microarray chip detector according to claim 1, characterized in that: The temperature control unit stabilizes the reagent temperature at 37±0.5°C, with a temperature fluctuation rate of ≤0.3°C / s.

6. The liquid path system of the electronic microarray chip detector according to claim 1, characterized in that: It also includes a motor-driven chip crimping mechanism to automatically press and separate the chip and the sealing ring of the manifold assembly, with a replacement time of less than 10 seconds.

7. The liquid path system of the electronic microarray chip detector according to claim 1, characterized in that: The main channel of the rotary valve is connected to the manifold assembly via a PTFE tube, and the spare channel supports calibration liquid access, waste liquid diversion, and the integration of new reagents.

8. The liquid path system of the electronic microarray chip detector according to claim 1, characterized in that: The manifold assembly has a built-in three-way solenoid valve to realize the chip flow channel bypass function.

9. A liquid circuit control method, applied to the liquid circuit system of the electronic microarray chip detector according to any one of claims 1 to 8, characterized in that include: Step 1: Turn on the heater to stabilize the temperature of the manifold assembly at 37±0.5℃; Step 2: Clean the flow channel at a flow rate of 150 μL / s. Switch channels when the temperature fluctuation is ≤0.3°C / s. A rotary valve is used to physically isolate the different reagent channels. After the reagent switch, a graded flushing process of SSC solution → water → NaCl is performed. Step 3: Electrical signal acquisition must simultaneously meet the following requirements: flow rate fluctuation ≤ ±2% for 5s, temperature fluctuation ≤ ±0.5°C, and pressure change rate ≤ 0.01 kPa / s.

10. The liquid circuit control method according to claim 9, characterized in that: The syringe pump extracts the reagent in a negative pressure manner, and the single aspiration volume does not exceed the single stroke volume of the syringe pump.

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