Detection device based on micro-fluidic chip
By using a detection device based on microfluidic chips, the problems of high cost, high energy consumption, uneven mixing, and flow channel blockage of existing water quality detection devices have been solved, achieving low-cost and high-precision water quality detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-03-27
AI Technical Summary
Existing water quality testing devices are costly, energy-intensive, require external power supply, use a large amount of reagents per test, and suffer from problems such as uneven mixing, bubble interference, and flow channel blockage, resulting in low testing accuracy and poor stability.
The detection device based on microfluidic chips includes a media delivery module, a multi-channel selection valve module, and a microfluidic chip module. Through the design of a media injection pump, a multi-channel flow seat, and a microfluidic flow channel, it achieves quantitative delivery of media, turbulent mixing, and bubble elimination, thereby reducing flow channel blockage and improving detection accuracy.
It reduces the amount and cost of testing reagents, achieves high-precision and low-energy water quality testing, avoids channel blockage and bubble interference, and improves the stability and accuracy of testing.
Smart Images
Figure CN121740754A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of microfluidics, in particular to a detection device based on a microfluidic chip. BACKGROUND
[0002] Although some existing water quality detection devices can realize automatic detection, they have problems of high cost, high energy consumption, and the need for external power supply. In addition, they consume a large amount of reagents for single detection, which cannot meet the demand for long-term continuous water quality detection in marine and other scenarios. In comparison, microfluidic chips have the core advantages of low reagent consumption, low cost, and low energy consumption for single detection, and can be powered by a battery without relying on external power supply lines. In addition, they can be used to build a monitoring network and are suitable for near-shore monitoring.
[0003] Phosphate is an essential nutrient element for the growth of aquatic organisms, but excessive discharge (such as domestic sewage, agricultural non-point source pollution, industrial wastewater, etc.) can lead to water eutrophication, causing phenomena such as blue-green algae and water bloom, resulting in depletion of dissolved oxygen in water, death of aquatic organisms, and disruption of ecological balance. From the perspective of water safety, excessive phosphate content in drinking water may affect human health, and excessive phosphate in industrial water may cause equipment scaling and corrosion, affecting production efficiency and product quality. Existing phosphate detection devices simply mix the detection reagents through a stirring and mixing device, and then use a spectrophotometer to detect the content of phosphate. This simple device has many technical problems that need to be solved: first, the reaction mixing module of the existing device is usually a simple stirring or static mixing structure, which can easily cause uneven mixing of the water sample and the color developing reagent, resulting in insufficient color developing reaction and directly affecting the detection accuracy; second, no effective bubble removal structure is provided during the sample injection and mixing process, and the generated bubbles can interfere with the absorbance detection of the spectrophotometric method and shield the electrode detection signal, further reducing the detection accuracy and even causing misjudgment; third, the flow channel design of the existing device is usually a single straight pipe or narrow diameter structure, and the impurities remaining in the water sample and the precipitate generated during the reaction can easily adhere to the inner wall of the flow channel, causing the flow channel to be easily blocked, which not only affects the detection efficiency, but also causes sample residue due to flow channel blockage, cross-contamination of subsequent detection samples, and indirect reduction of detection accuracy; fourth, the three problems of uneven mixing, bubble interference, and flow channel blockage are superimposed, ultimately leading to the common problems of low detection accuracy, poor stability, and high maintenance frequency of the existing devices. SUMMARY
[0004] In view of the above problems of the prior art, the present application provides a detection device based on a microfluidic chip, which has low detection cost, low reagent consumption, uniform mixing, reduced bubble interference, and a flow channel that is not easily blocked, thereby achieving high detection accuracy.
[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is: a detection device based on a microfluidic chip, the structure of the device comprises a medium conveying module, a multi-channel selection valve module and a microfluidic chip module; the medium conveying module comprises a medium injection pump and an injection driving motor, the output shaft of the injection driving motor is connected with the driving rod of the medium injection pump to drive the driving rod to extend or retract; the multi-channel selection valve module comprises a multi-channel flow channel seat, a valve seat and a multi-channel valve driving motor, the multi-channel flow channel seat comprises a plurality of medium conveying connectors, at least one of the plurality of medium conveying connectors is connected with the medium conveying module through a conveying pipeline; the multi-channel flow channel seat is connected with the valve seat, a selection channel seat is arranged in the valve seat, the selection channel seat is driven to rotate by the multi-channel valve driving motor to make two of the plurality of medium conveying connectors communicate with each other to realize the input and output of the medium; the microfluidic chip module comprises a medium inlet and a medium outlet, the medium inlet and the medium conveying connector are connected with each other through a conveying pipeline, and the medium outlet is connected with a collection device through a conveying pipeline; a microfluidic flow channel and a microfluidic detection channel that are connected with each other are arranged between the medium inlet and the medium outlet, the microfluidic flow channel is used for the medium to flow through and finally enter the microfluidic detection channel, and the outlet of the microfluidic detection channel is connected with the medium outlet.
[0006] By adopting the above structure, the present application forms a microfluidic-based detection device capable of detecting phosphate or total nitrogen and the like by the mutual combination of the three modules. Since the microfluidic chip assembly is adopted, the use amount of the detection reagent can be greatly reduced, the cost and the occupied space of the device can be saved. In addition, the present application also enhances the mixing effect between various media by forming turbulent flow of the medium in the microfluidic flow channel, thereby improving the detection accuracy, and also reduces the generation of bubbles to avoid the blockage of the flow channel, so that the medium conveying in the detection process is more smooth. In addition, the present application adopts a novel multi-channel valve module assembly in the input process of the medium, a plurality of connectors are arranged on the multi-channel flow channel seat, when the selection channel seat is rotated to the specified target position, it is accurately connected with the corresponding target connector in the multi-channel flow channel seat to form a sealed communication structure, thereby realizing the quantitative extraction and directional conveying of the reagent, and effectively reducing the influence of the additional sensor on the stability of the selection valve.
[0007] Further, the medium injection pump is arranged on the fixed base, the medium injection pump comprises a medium storage tube, one end of the driving rod is provided with a piston, the piston is slidingly fitted in the medium storage tube, and the piston slides back and forth along the medium storage tube under the driving of the injection driving motor; by adopting the structure, sufficient pump-in pressure can be provided for the medium, so that the medium can smoothly enter the multi-channel valve body assembly or be extracted from the multi-channel valve body assembly into the medium storage tube.
[0008] Further, the fixed base is provided with a heating sheet and a temperature sensor near the position of the medium storage tube; by adopting the structure, the heating sheet can heat the medium in the medium storage tube, so that the dissolution and reaction of the medium are accelerated; and the temperature sensor can detect the temperature of the medium in real time, so that the heating accuracy is improved.
[0009] Further, the fixed base is provided with a fan near the position of the medium storage tube; by adopting the structure, after the medium in the medium storage tube is heated and reacted by the heating sheet, the medium is cooled by the fan, and then is transported into the medium conveying connector through the pipeline to enter the microfluidic chip module for detection.
[0010] Further, the plurality of medium conveying connectors are located at one end of the thickness direction of the multi-channel flow channel seat, a plurality of fine holes are arranged at the opposite end of the thickness direction of the multi-channel flow channel seat, the plurality of fine holes are respectively connected to the plurality of medium conveying connectors, and the distribution area of the plurality of fine holes is matched with the end surface area of the selection channel seat; by adopting the structure, the selection channel seat is located at a specific position, two medium conveying connectors corresponding to the position are connected to each other, the medium is conveyed into the corresponding fine hole, and then is led out from the other medium conveying connector under the guidance of the selection channel seat, so that the connection of different connectors and the introduction and flow of the medium are realized.
[0011] Further, the inner diameters of the plurality of fine holes connected to the plurality of medium conveying connectors are curvedly extended; that is, the extension trend of the fine hole is not linearly extended along the thickness direction of the multi-channel flow channel seat to be connected to the corresponding medium conveying connector, but is curvedly extended to be connected, so that the end surface area of the selection channel seat and the volume thereof can be saved, the driving stroke is more energy-saving, the sealing connection between the fine hole and the selection channel seat can be realized, and the fine hole can be concentrated in the end surface area of the selection channel seat.
[0012] Further, the one medium conveying joint is located at the center of the end face of the multi-channel flow channel seat, and the rest of the plurality of medium conveying joints are distributed equidistantly around the center of the one medium conveying joint, and the arrangement mode of the plurality of holes is adapted to the arrangement mode of the one medium conveying joint at the center of the end face and the rest of the plurality of medium conveying joints; the end face of the selection channel seat abutting against the multi-channel flow channel seat is provided with a groove, and the extension length of the groove is adapted to the spacing between the hole for communicating with the medium output joint at the center of the end face and one hole of the plurality of holes for respectively communicating with the plurality of medium conveying joints around; that is, the extension length formed between the one hole at the center and any one hole of the plurality of holes around is completely covered by the groove, so that the two joints respectively communicating with the two holes realize the flow of the medium in the groove; by adopting the structure, equidistant communication between the holes for introducing the medium and the joints can be realized, and the structure is the most simplified; and the groove can cover one hole for introducing the medium and one hole for outputting the medium, so that when the selection channel seat is rotated to different positions, the groove can cover different holes for introducing the medium, so as to realize selection between different medium conveying joints and the medium outlet joint, so as to meet the introduction of multiple media by one multi-way valve assembly.
[0013] Further, the outer wall of the selection channel seat extends the first limiting block protruding radially, and the inner side wall of the valve seat is provided with the second limiting block capable of abutting against each other; by adopting the structure, the motor can realize the communication between different medium conveying joints and the medium outlet joint during driving the selection channel seat to rotate, and the position of the selection channel seat is not inaccurate due to excessive rotation; and after the first limiting block and the second limiting block abut against each other, the selection channel seat can also be used to control the rotation to stop, so as to realize the zero detection of the inlet and outlet positions.
[0014] Further, the selection channel seat comprises a first channel seat and a second channel seat connected with each other, the outer diameter of the second channel seat is greater than that of the first channel seat, the groove is arranged on the end face of the first channel seat, and the first limiting block is arranged on the outer wall of the second channel seat; the first bearing is sleeved on the first channel seat, the accommodating cavity is arranged in the second channel seat, the second bearing is sleeved in the accommodating cavity, and the output shaft of the multi-way valve driving motor penetrates into the channel seat from the shaft hole of the second bearing and is in interference fit with the channel seat; by adopting the structure, the selection channel seat can be limited in the valve seat through the two stepped channel seats, and the rotation stroke of the motor can be smoother, and the rotation angle is not stuck.
[0015] Further, the first bearing is a ball bearing, and the second bearing is a thrust ball bearing (such as a thrust bearing); or both can be ball bearings; with this structure, the smoothness and accuracy of the rotation angle of the selection channel seat can be further ensured, the accuracy of the channel connection of different media can be realized, and the setting of the bearing can also be used to reduce the rotating friction to maintain the stability of the combination interface of each part.
[0016] Further, the plurality of medium conveying joints are conical structures, and the outer wall of the conical structure is provided with an anti-skid ring; with this structure, the narrow-to-wide conical structure can facilitate the insertion and connection of the conveying pipeline, and the setting of the anti-skid ring can also prevent the pipeline from falling off, thereby maintaining the stability and sealing performance of the pipeline connection.
[0017] Further, the multi-way valve driving motor is a TMC series motor drive; with this specification of motor, it has a stallGuard function, which can be used to realize sensorless zeroing, that is, when the selection channel seat rotates to hit the limit block on the valve seat, the TMC series motor drive triggers the stop through the stall detection, completing the positioning and zeroing.
[0018] Further, the microfluidic chip module further comprises a first housing and a second housing connected to each other, the first housing and the second housing form a accommodating cavity accommodating the microfluidic chip, the microfluidic chip is provided with the microfluidic flow channel and the microfluidic detection channel, one end of the microfluidic flow channel is in communication with the medium inlet, and the other end is in communication with the microfluidic detection channel; the medium outlet is in communication with the outlet of the microfluidic detection channel; with this structure, the medium first flows through the microfluidic flow channel on the microfluidic chip to form a turbulent flow, and then enters the microfluidic detection channel to realize full mixing and detection, the turbulent flow formed by the microfluidic flow channel can eliminate the foam in the medium, thereby avoiding channel blockage and providing more accurate guarantee for subsequent detection.
[0019] Further, the first housing is located at the upper part of the second housing, and the microfluidic flow channel faces one side of the second housing; that is, during use, the opening in the thickness direction of the microfluidic flow channel faces downward; with this structure, when the medium enters the microfluidic flow channel, the medium flows more stably due to the microfluidic flow channel facing the second housing side, and when entering the microfluidic detection channel, it can gradually rise from the bottom of the channel to fill the entire microfluidic detection channel, which makes the medium mixing more balanced and gentle, and also prevents the formation of height difference to cause the medium to shake and cause inaccurate detection.
[0020] Further, the microfluidic flow channel comprises a flow channel and a plurality of turbulent flow columns located in the flow channel, the outer diameter of the turbulent flow column is not less than the width of the flow channel, and the two sides of each turbulent flow column are provided with an expansion flow channel matched with the outer contour of the turbulent flow column; by adopting the structure, the medium flow process and the multiple impacts of the plurality of turbulent flow columns can form more stable turbulent flow, and further eliminate foam.
[0021] Further, the flow channel is provided with a plurality of bends to form a plurality of parallel flow channels, and the bend positions of the adjacent two flow channels form a smooth arc bend; by adopting the structure, the smooth bend setting can move the bubbles out of the photoelectric sensor to avoid the influence of bubble scattering on detection; and the parallel arrangement of the plurality of flow channels can also prolong the length of the flow channel, while avoiding the structure of the microfluidic chip being too long.
[0022] Further, the microfluidic detection channel is arranged in parallel with the microfluidic flow channel, and the extension depth of the microfluidic flow channel is less than the extension depth of the microfluidic detection channel; by adopting the structure, the channels and detection channels can be reasonably arranged within the width range of the microfluidic chip, without causing a single extension that is too long, and the overall required extension length can be maintained; and the depth difference allows the medium to be fully collected and mixed in the detection channel, ensuring detection accuracy.
[0023] Further, one end of the first shell in the length direction of the microflow detection channel is provided with a light source accommodating hole, and a detection light source is arranged in the light source accommodating hole; by adopting the structure, the position of the light source can be set to more accurately detect the sample to be measured in the microfluidic detection channel.
[0024] Further, the first shell and the second shell are provided with a photoelectric sensor at the opposite end of the light source accommodating hole in the length direction, the first shell is provided with a light transmission hole at the corresponding end, and the photoelectric sensor, the light transmission hole and the detection light source are located on the same straight line; that is, the photoelectric sensor, the light transmission hole and the detection light source are on the same straight line along the length direction, by adopting the structure, the position of the light source can be set to more accurately detect the sample to be measured in the microfluidic detection channel.
[0025] Further, the microfluidic chip is covered with a light shield on the side surface close to the second shell, and the end surface area of the light shield is greater than the end surface area of the microfluidic chip covered thereby; by adopting the structure, the light shield can be provided to prevent light scattering in the microfluidic chip from affecting the measurement accuracy.
[0026] Further, the microfluidic detection channel has a length of 30 mm, a width of 4 mm and a height of 4 mm; the structure supports the functions of washing the silt in the flow channel and backwashing the flow channel, is compact in structure, small in size, convenient to replace and high in detection precision; the structure can be used for detecting the content of phosphorus in phosphate or the total nitrogen content, and the detection of the content of phosphorus in phosphate is based on the phosphomolybdate blue colorimetric method. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 The present application is based on the structural schematic diagram of the first view of the detection device of the microfluidic chip (including the support frame).
[0028] Figure 2 The present application is based on the structural schematic diagram of the second view of the detection device of the microfluidic chip (including the support frame).
[0029] Figure 3 The present application is based on the structural schematic diagram of the third view of the detection device of the microfluidic chip (including the support frame).
[0030] Figure 4 The present application is based on the structural schematic diagram of the detection device of the microfluidic chip.
[0031] Figure 5 The present application is based on the structural schematic diagram of the medium conveying module.
[0032] Figure 6 The present application is based on the structural schematic diagram of the multi-channel selection valve module.
[0033] Figure 7 The present application is based on the structural schematic diagram of the first view of the explosion diagram of the multi-channel selection valve module.
[0034] Figure 8 The present application is based on the structural schematic diagram of the second view of the explosion diagram of the multi-channel selection valve module.
[0035] Figure 9 The present application is based on the structural schematic diagram of the first view of the cross-sectional view of the multi-channel selection valve module.
[0036] Figure 10 The present application is based on the structural schematic diagram of the second view of the cross-sectional view of the multi-channel selection valve module.
[0037] Figure 11 The present application is based on the structural schematic diagram of the multi-channel flow channel seat.
[0038] Figure 12 The present application is based on the structural schematic diagram of the cross-sectional view of the multi-channel flow channel seat.
[0039] Figure 13 The present application is based on the structural schematic diagram of the selection channel seat.
[0040] Figure 14Structure diagram of the valve seat of the present application.
[0041] Figure 15 Structure diagram of the microfluidic chip module of the present application.
[0042] Figure 16 Structure diagram of the first exploded view of the microfluidic chip module of the present application.
[0043] Figure 17 Structure diagram of the second exploded view of the microfluidic chip module of the present application.
[0044] Figure 18 Structure diagram of the microfluidic chip module of the present application after removing the first shell.
[0045] Figure 19 Structure diagram of the first view of the microfluidic chip of the present application.
[0046] Figure 20 Structure diagram of the second view of the microfluidic chip of the present application.
[0047] Figure 21 Structure diagram of the first shell of the present application.
[0048] Figure 22 Structure diagram of the second shell of the present application.
[0049] As shown in the accompanying drawings: S1. Medium conveying module, 101. Medium injection pump, 1011. Medium storage tube, 102. Injection driving motor, 103. Driving rod, 104. Fan, S2. Multi-channel selection valve module, 201. Multi-channel flow channel seat, 2011. Medium conveying joint, 2012. Anti-skid ring, 202. Valve seat, 203. Multi-valve driving motor, 204. Selection channel seat, 2041. First channel seat, 2042. Second channel seat, 205. Fine hole, 206. Groove, 207. First limiting block, 208. Second limiting block, S3. Microfluidic chip module, 301. Medium inlet, 302. Medium outlet, 303. Microfluidic flow channel, 3031. Flow channel, 3032. Turbulence column, 3033. Expanded flow channel, 3034. Bend, 304. Microfluidic detection channel, 305. First shell, 306. Second shell, 307. Microfluidic chip, 308. Light source accommodating hole, 309. Light transmission hole, S4. Fixed base, S5. Heating sheet, S6. Temperature sensor, S7. First bearing, S8. Second bearing, S9. Detection light source, S10. Photoelectric sensor, S11. Light shield, S12. Support frame, S13. Circuit board, S14. Medium storage tank. DETAILED DESCRIPTION
[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments and drawings. Obviously, the described embodiments are only the preferred embodiments but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative effort belong to the scope of the present application. Furthermore, it should be noted that when a component is referred to as being "fixed" to another component, it can be directly on the other component or can be connected via another intermediate component. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or can be connected via another intermediate component. When a component is referred to as being "disposed" on another component, it can be directly on the other component or can be connected via another intermediate component. The terms "vertical", "horizontal", "left", "right", and similar terms used herein are for illustrative purposes only; unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The use herein of the terms "including", "comprising", "having" and the like are specifically intended to be equivalent to the term "consisting of".
[0051] As shown in the accompanying Figures 1-22 The device structure includes a medium conveying module S1, a multi-channel selection valve module S2 and a microfluidic chip module S3. The medium conveying module S1 includes a medium injection pump 101 and an injection driving motor 102. The output shaft of the injection driving motor 102 is connected with the driving rod 103 of the medium injection pump 101 to drive the driving rod 103 to extend or retract. The multi-channel selection valve module S2 includes a multi-channel flow channel seat 201, a valve seat 202 and a multi-channel valve driving motor 203. The multi-channel flow channel seat 201 includes a plurality of medium conveying connectors 2011. At least one of the plurality of medium conveying connectors 2011 is connected with the medium conveying module S1 through a conveying pipeline. The multi-channel flow channel seat 201 is connected with the valve seat 202. The valve seat 202 is provided with a selection channel seat 204. The selection channel seat 204 is driven to rotate by the multi-channel valve driving motor 203, so that two of the plurality of medium conveying connectors 2011 are connected with each other to realize the input and output of the medium (i.e. one connector is used for introducing the medium and the other connector is used for leading out the medium). The microfluidic chip module S3 includes a medium inlet 301 and a medium outlet 302. The medium inlet 301 is connected with one of the medium conveying connectors 2011 through a conveying pipeline. The medium outlet 302 is connected with a collection device (such as a waste liquid tank) through a conveying pipeline. Figures 1-2 andFigure 4 As shown, the collecting device can be a medium storage tank S14) connected; between the medium inlet 301 and the medium outlet 302, a microfluidic flow channel 303 and a microfluidic detection channel 304 are provided for intercommunication, the microfluidic flow channel 303 is for the medium to flow through and finally enter into the microfluidic detection channel 304, the outlet of the microfluidic detection channel 304 is connected with the medium outlet 302; Specifically, the medium conveying module S1 of the present application mainly provides the power of medium conveying, and different media are input into the multi-channel selection valve module S2 according to the detection needs; The medium injection pump 101 therein can be equivalent to a syringe, and the medium conveying action is realized by driving the rod in the pipe to and fro; The multi-channel selection valve module S2 of the present application has a plurality of medium conveying joints, according to the different detection media, different media can be connected through different joints to make the media enter into the joint, and then be conveyed into the medium inlet 301 or the medium storage pipe 1011, different joints can be used for introducing different media, and can be introduced from the same joint into the medium conveying module for heating, mixing reaction, cooling, and then input into the joint and into the microfluidic chip structure; The multi-channel flow channel seat 201 is an end structure, assembled at one end of the whole multi-channel selection valve module S2, which is convenient for communication with the conveying pipeline, and the valve seat 202 is a transition structure connecting the multi-channel flow channel seat 201 and the driving motor 203, the selection channel seat 204 connected with the motor output shaft is arranged inside, the driving selection channel seat 204 is rotated to realize the communication between different introduction joints and outlet joints, realize the introduction and output of the medium; The microfluidic chip module S3 of the present application mainly introduces the medium into the microfluidic flow channel 303 to form a turbulent flow, so as to eliminate the foam and improve the detection accuracy; The microfluidic flow channel 303 and the microfluidic detection channel 304 are both provided on the microfluidic chip 307, that is, the microfluidic flow channel 303 and the microfluidic detection channel 304 structure are formed on the plate-shaped microfluidic chip 307 in the thickness direction downwardly recessed, and the medium inlet and outlet are provided (correspondingly, the medium inlet and outlet corresponding to the medium inlet and outlet on the microfluidic chip are provided on the first shell for intercommunication) to realize the flow and detection in the microfluidic flow channel and the detection channel and the flow out of the collection.
[0052] With the above structure, the three modules are combined to form a microfluidic-based detection device capable of detecting phosphate or total nitrogen, etc. The device can greatly reduce the amount of detection reagent, save cost and occupy space due to the use of microfluidic chip components. In addition, the microfluidic flow channel is provided to form a turbulent flow of the medium in the flow channel, thereby enhancing the mixing effect between the various media to improve the accuracy of the detection, and also reducing the generation of bubbles to avoid the blockage of the flow channel, so that the medium conveying in the detection process is more smooth. In addition, the multi-way valve module assembly of a new structure is used in the input process of the medium, a plurality of joints are formed on the multi-channel flow channel seat, and when the channel seat is rotated to the specified target position, it is accurately connected with the corresponding target joint in the multi-channel flow channel seat to form a sealed communication structure, thereby realizing quantitative extraction and directional conveying of the reagent, and effectively reducing the influence of the additional sensor on the stability of the selection valve.
[0053] As shown in the accompanying drawings, Figures 1-5 The medium injection pump 101 is provided on the fixed base S4, the medium injection pump 101 comprises a medium storage tube 1011, one end of the driving rod 103 is provided with a piston, the piston is slidingly fitted in the medium storage tube 1011, and the piston is driven by the injection driving motor 102 to slide back and forth along the medium storage tube 1011. Specifically, the motor gives a driving force to the driving rod, so that the piston slides back and forth in the medium storage tube 1011 to realize the pulling and pushing actions of the medium. With this structure, sufficient pumping pressure can be provided for the medium to smoothly enter the multi-channel valve body assembly or be extracted from the multi-channel valve body assembly into the medium storage tube 1011.
[0054] As shown in the accompanying drawings, Figure 1 The fixed base S4 is provided with a heating sheet S5 (which can be a commercially available electric heating sheet that provides a heat source by power supply, or can also use a heating sheet structure of a solar panel) and a temperature sensor S6 near the position of the medium storage tube 1011. Specifically, mounting holes for accommodating the heating sheet S5 and the temperature sensor S6 are formed in the position of the fixed base S4 for fixing the medium storage tube 1011, wherein the heating sheet S5 can be located on the side of the fixed medium storage tube 1011 to as large as possible to heat the medium in the fixed medium storage tube 1011, and the temperature sensor S6 is relatively closer to the medium storage tube 1011 than the heating sheet S5 to realize accurate temperature sensing. With this structure, the heating sheet can heat the medium in the medium storage tube to accelerate the dissolution and reaction of the medium, and the temperature sensor can detect the temperature of the medium in real time to improve the accuracy of heating.
[0055] As attached Figures 1-2 As shown in Figures 4-5, a fan 104 is provided on the fixed base S4 near the medium storage tube 1011. With this structure, after the medium in the medium storage tube 1011 is heated and reacted by the heating element, it is cooled by the fan and then transported through the pipeline to the medium delivery connector to enter the microfluidic chip module for detection.
[0056] As attached Figures 6-14 As shown, the plurality of media delivery connectors 2011 described in this application are located at one end of the multi-channel flow channel seat 201 in the thickness direction. A plurality of fine holes 205 are provided at the opposite end of the multi-channel flow channel seat 201 in the thickness direction. Each fine hole 205 is connected to one of the plurality of media delivery connectors 2011 (i.e., one fine hole connects to one connector). The distribution area of the plurality of fine holes 205 is adapted to the end face area of the selection channel seat 204. Specifically, these fine holes are distributed on the back side of the multi-channel flow channel seat and fit against the end face of the selection channel seat. The area formed by 205 is no larger than the end face area of the selection channel seat 204, that is, the end face of the selection channel seat can completely cover these fine holes 205; with this structure, after the selection channel seat 204 is located in a specific position, the two media delivery connectors 2011 corresponding to that position are connected to each other (one as the connector for introducing the medium and the other as the connector for exiting the medium). At this time, the medium is delivered into the corresponding fine hole 205, and then led out from the other media delivery connector 2011 under the guidance of the selection channel seat 204, realizing the connection of different connectors and the introduction and flow of the medium.
[0057] As an example, see attached Figures 9-10 and Figure 12 As shown, the inner diameter of the multiple fine holes 205 connected to the multiple media conveying connectors 2011 in this application is a curved extension; that is, the extension trend of the fine holes 205 is not a straight extension along the thickness direction of the multi-channel flow seat to connect with the corresponding media conveying connector, but a curved extension connection. This can save the end face area and volume of the selection channel seat, and the driving process is more energy-efficient. It can also achieve a sealed connection with the fine holes; it is also convenient to concentrate the fine holes within the end face area of the selection channel seat.
[0058] As attached Figures 6-7 , Figures 9-12As shown in the drawings, one medium delivery connector 2011 is located at the center of the end face of the multi-channel flow channel seat 201, and the remaining plurality of medium delivery connectors 2011 are distributed equidistantly around the center position of the medium delivery connector 2012, and the arrangement mode of the plurality of holes 205 is adapted to the arrangement mode of the one medium delivery connector at the center of the end face and the remaining plurality of medium delivery connectors (the one at the center of the end face can be used as an output and input connector, and the surrounding ones can be used as input connectors); the end face of the selection channel seat 204 abutting the multi-channel flow channel seat 201 is provided with a groove 206, and the extension length of the groove 206 is adapted to the spacing between the hole 205 for communicating with the medium output connector 2011 at the center of the end face and one of the plurality of holes 205 for communicating with the plurality of medium delivery connectors 2011 around the center; that is, the extension length formed between the one hole at the center and any one of the plurality of holes around the center is completely covered by the groove 206, so that the two connectors respectively communicating with the two holes realize the flow of medium with each other in the groove; by adopting the structure, equidistant communication between the medium introduction hole and the connector can be realized, and the structure is simplified; and the groove can cover one medium introduction hole and one medium outlet hole, so that when the selection channel seat is rotated to different positions, the groove can cover different medium introduction holes, realizing selection between different medium delivery connectors and the medium outlet connector, so as to satisfy that one multi-channel valve assembly can realize introduction of multiple media.
[0059] As shown in the drawings, Figures 7-8 , Figures 13-14 As shown in the drawings, the outer wall of the selection channel seat 204 extends a first limiting block 207 protruding in the radial direction, and the inner wall of the valve seat 202 is provided with a second limiting block 208 capable of abutting each other; specifically, the first limiting block 207 and the second limiting block 208 are in contact with each other to form interference when the motor drives the selection channel seat 204 to rotate to a certain position in the radial direction, at which time the selection channel seat 204 no longer rotates to realize zero detection of the inlet and outlet positions; by adopting the structure, the motor can realize communication between different medium delivery connectors and the medium outlet connector during driving the selection channel seat to rotate, and the selection channel seat will not be inaccurately positioned due to excessive rotation; and after the first limiting block and the second limiting block abut each other, the rotation of the selection channel seat can be stopped to realize zero detection of the inlet and outlet positions.
[0060] As shown in the drawings, Figures 7-8 , Figures 13-14As shown, the selection channel seat 204 described in the application includes a first channel seat 2041 and a second channel seat 2042 connected to each other in the upper and lower directions, the outer diameter of the second channel seat 2042 is greater than that of the first channel seat 2041, the groove 206 is arranged on the end face of the first channel seat 2041 (on the same side as the medium conveying connector), and the first limiting block 207 is arranged on the outer wall of the second channel seat 2042 (radially protruding); the first bearing S7 is sleeved on the first channel seat 2041, the second bearing S8 is sleeved in the accommodating cavity in the second channel seat 2042 (the inner diameter of the accommodating cavity and the outer diameter of the second bearing S8 are matched with each other, and can be in interference fit with the accommodating cavity), and the output shaft of the multi-way valve driving motor 203 penetrates into the channel seat from the shaft hole of the second bearing S8 and is in interference fit with the channel seat (to drive the multi-channel flow channel seat to rotate circumferentially, so that the groove and the two holes are aligned and covered, and the multiple different medium conveying connectors are connected with one medium outlet connector). By arranging the two stepped channel seats, the selection channel seat can be limited in the valve seat by the two bearings, the rotation stroke of the motor can be smoother, and the rotation angle is not stuck.
[0061] As an example, the first bearing S7 described in the application is a ball bearing (ball bearing), and the second bearing S8 is a thrust ball bearing (such as a thrust bearing); they can also be ball bearings; by adopting this structure, the smoothness and accuracy of the rotation angle of the selection channel seat can be further ensured, the accuracy of the channel connection of different media is realized, and the setting of the bearing can also be used to reduce the rotation friction to maintain the stability of the combination interface of each part.
[0062] As shown in the accompanying Figures 6-7 , Figures 9-12 As shown, the multiple medium conveying connectors 2011 described in the application are in a conical structure, and the outer wall of the conical structure is provided with an anti-skid ring 2012. Specifically, the anti-skid ring 2012 can be arranged at least two on the upper and lower sides along the length direction of the connector. By adopting this structure, the narrow-to-wide conical structure can facilitate the insertion and connection of the conveying pipe, and the setting of the anti-skid ring can prevent the pipe from falling off, thereby maintaining the stability and sealing performance of the pipe connection.
[0063] As an example, the multi-way valve driving motor 203 described in the application is a TMC series motor drive. By adopting this specification of motor, the stallGuard function can be used to realize sensorless zero setting, that is, when the selection channel seat rotates to hit the limiting block on the valve seat, the TMC series motor drive triggers the stop through the stall detection, and completes the positioning and zero setting.
[0064] As shown in the accompanying Figures 16-22As shown, the microfluidic chip module S3 described in the application further comprises a first shell 305 and a second shell 306 connected to each other, the first shell 305 and the second shell 306 form a accommodating cavity accommodating the microfluidic chip 307, the microfluidic chip 307 is provided with the microfluidic flow channel 303 and the microfluidic detection channel 304, one end of the microfluidic flow channel 303 is communicated with the medium inlet 301, and the other end is communicated with the microfluidic detection channel 304; the medium outlet 302 is communicated with the outlet of the microfluidic detection channel 304; specifically, the first shell and the second shell are closed in the upward and downward directions to form the accommodating cavity, and then the plate-shaped microfluidic chip is placed in the accommodating cavity and fixed and protected by the shell; wherein the microfluidic flow channel and the microfluidic detection channel are formed on the main body of the microfluidic chip and are connected to each other; by using this structure, the medium first flows through the microfluidic flow channel on the microfluidic chip to form turbulent flow, and then enters the microfluidic detection channel to realize sufficient mixing and detection, the turbulent flow formed by the microfluidic flow channel can eliminate the foam in the medium, thereby avoiding channel blockage and providing more accurate guarantee for subsequent detection.
[0065] As shown in the accompanying drawings Figures 15-16 The first shell 305 described in the application is located at the upper part of the second shell 306, and the microfluidic flow channel 303 faces one side of the second shell 305; that is, the opening in the thickness direction of the microfluidic flow channel faces downward during use; by using this structure, when the medium enters the microfluidic flow channel, the medium runs more smoothly due to the microfluidic flow channel facing the second shell side, and when entering the microfluidic detection channel, the medium gradually rises from the bottom of the channel to fill the entire microfluidic detection channel, which makes the medium mix more evenly and gently, and also avoids the formation of height difference to cause the medium to shake and cause inaccurate detection.
[0066] As shown in the accompanying drawings Figure 17 , Figures 19-20 As shown in the accompanying drawings The microfluidic flow channel 303 described in the application comprises a flow channel 3031 and a plurality of turbulent columns 3032 located in the flow channel 3031, the outer diameter of the turbulent column 3032 is not less than the width of the flow channel 3031, and each turbulent column 3032 is provided with an expansion flow channel 3033 matched with the outer contour of the turbulent column 3032; specifically, the flow channel of the application is provided with a plurality of flow channels extending along the length direction of the microfluidic chip body, the plurality of flow channels are bent at the length ends to form a structure communicated with each other, and a plurality of turbulent columns are arranged in each flow channel, the height of the turbulent column is consistent with the depth of the flow channel, so that the medium flowing process will collide with the side walls of the plurality of turbulent columns, forming turbulent flow to eliminate foam; by using this structure, the medium flowing process can collide with the plurality of turbulent columns multiple times to form more stable turbulent flow, further eliminating the foam.
[0067] As shown in the accompanying drawings Figures 19-20 The flow channel 3031 described in the present application is provided with multiple bends 3034 to form multiple parallel flow channels 3031, and the bend positions of adjacent two flow channels 3031 form smooth arc-shaped bends; specifically, the end bends of each flow channel are arc-shaped bend structures; with this structure, the smooth bends can move the bubbles out of the photoelectric sensor to avoid the influence of bubble scattering on detection; and the multiple parallel flow channels can also lengthen the flow channel, while avoiding an excessively long microfluidic chip structure.
[0068] As shown in the accompanying drawings Figures 19-20 The microfluidic detection channel 304 described in the present application is arranged in parallel with the microfluidic flow channel 303 (i.e., both extend along the length direction of the microfluidic chip body, and form multiple channels in the width direction), and the extension depth of the microfluidic flow channel 303 is less than the extension depth of the microfluidic detection channel 304 (i.e., the microfluidic detection channel has a deeper depth to accommodate more media to mix with each other here); with this structure, the channels and detection channels can be reasonably arranged within the width range of the microfluidic chip, without causing a single extension that is too long, while maintaining the required overall extension length; and the depth difference allows the media to fully collect and mix in the detection channel, ensuring detection accuracy.
[0069] As shown in the accompanying drawings 16-17 and Figure 21 The first housing 305 described in the present application is provided with a light source accommodating hole 308 at one end in the length direction of the microfluidic detection channel 304, and a detection light source S9 is arranged in the light source accommodating hole 308; specifically, the detection light source can use a commercially available 880nm parallel light source; with this structure, the position of the light source can be set to more accurately detect the sample to be tested in the microfluidic detection channel.
[0070] As shown in the accompanying drawings Figures 16-17 and Figure 21 The first housing 305 and the second housing 306 described in the present application are provided with a photoelectric sensor S10 at the opposite end relative to the light source accommodating hole 308 in the length direction, the first housing 305 is provided with a light-transmitting hole 309 at the corresponding end, and the photoelectric sensor S10, the light-transmitting hole 309 and the detection light source S9 are located on the same straight line; that is, the photoelectric sensor S10, the light-transmitting hole 309 and the detection light source S9 are on the same straight line in the length direction, and with this structure, the position of the light source can be set to more accurately detect the sample to be tested in the microfluidic detection channel.
[0071] As shown in the accompanying drawings Figures 16-18As shown, the microfluidic chip 307 described in the present application is covered with a light shield S11 on one side of the second housing 306, the end surface area of the light shield S11 is greater than the end surface area of the microfluidic chip 307 covered by the light shield S11; that is, the surface of the light shield S11 and the microfluidic chip 307 can completely cover the surface of the microfluidic chip 307; by using this structure, by equipping the light shield, the scattering of light in the microfluidic chip can be prevented to affect the measurement accuracy.
[0072] As an example, the detection light source described in the present application is a commercially available 880nm parallel light source, the photoelectric sensor is an opt101 photoelectric sensor, the length of the microfluidic detection channel is 30mm, the width is 4mm, and the height is 4mm; by using this structure, the silt in the cleaning flow channel and the backflushing flow channel function are supported, the structure is compact, the volume is small, it is convenient to replace and the detection precision is high; this structure can be used to detect the content of phosphorus in phosphate or total nitrogen content, wherein the detection of the content of phosphorus in phosphate is based on the phosphomolybdate blue colorimetric method.
[0073] As an example, the microfluidic detection device described above in the present application is used for phosphate detection, that is, for detecting the content of phosphorus in phosphate, the detection method is based on the phosphomolybdate blue colorimetric method, specifically the content of the method includes: under acidic conditions, phosphate ions react with ammonium molybdate to generate phosphomolybdate complex, and then under the catalytic action of ascorbic acid and antimony ions (Sb³⁺), it is reduced to deep blue phosphomolybdate blue complex, the color intensity is proportional to the concentration of phosphate.
[0074] With the method, combined with the microfluidic detection device of the application, the specific detection process for phosphate detection is as follows: first, as an example, according to the drawings, the multi-channel flow channel seat 201 of the application is provided with medium conveying joints 2011, of which one is in the center and eight are around the center; the one in the center and the medium conveying module are connected to each other through a conveying pipeline, and then one of the eight joints around the center is connected to a conveying pipeline connected to the microfluidic chip module; the remaining joints around the center can be used as a potassium persulfate solution introduction joint, an ascorbic acid solution introduction joint, a color developing agent introduction joint, and a water sample detection joint; the water sample introduction joint is connected, and the water sample to be detected is extracted by the injection pump into the microfluidic chip; the potassium persulfate solution introduction joint is connected, and the potassium persulfate solution is extracted into the medium storage tube; the medium storage tube is used as a reaction container for heating and digestion; after heating and mixing, the ascorbic acid solution introduction joint is connected, and the ascorbic acid solution is extracted into the medium storage tube; the color developing agent introduction joint is connected, and the color developing agent is extracted into the medium storage tube; the air in the channel formed between the two joints connected to the grooves is extracted to empty the excess liquid; the above process is to extract the above reagents by high-frequency switching of the multi-channel selection valve in turn to mix uniformly; after cooling, the joint connected to the conveying pipeline connected to the microfluidic chip module is connected, and the uniformly mixed solution is introduced into the microfluidic chip from the pipeline connected to the medium storage tube; the medium in the microfluidic chip will first pass through the microfluidic flow channel 301 to eliminate foam, and then enter the microfluidic detection channel 304 for detection; the detection process uses a 880nm parallel light source to irradiate a 30mm long detection channel, and a TIopt101 photoelectric sensor is used to read the absorbance to calculate the phosphate concentration; after detection, the detection liquid is discharged through the outlet pipeline into a waste bottle; in addition, the structure of the application can also clean the silt through the backflush flow channel function, and the smooth elbow design can avoid bubble interference; the device of the application can perform phosphomolybdate blue colorimetric method to detect phosphate content, and can support efficient mixing, avoid bubble generation, realize accurate detection and flow channel cleaning; and the structure of the detection device is small in size, easy to replace and comprehensive in parameters.
[0075] The device of the application can be fixed on the support frame, and the circuit board is arranged on the support frame, and the circuit board is electrically connected with the driving motor and the detection module to control the work of each part (the PLC technology commonly used in the industry for controlling the operation of the servo motor can be used, and detailed description is not required), such as controlling the motor-driven piston of the medium conveying module to perform medium extraction and conveying action, heating and cooling, etc.; the motor of the multi-channel selection valve module is rotated to realize the extraction and conveying of different media on different joints; such as controlling the detection module to perform automatic detection, etc.; the driving motor of the application can adopt a servo motor, which is accurate in control and convenient to purchase; the microfluidic flow channel of the application can be controlled between 100-2000 microns (such as the width of the flow channel of the application can be 900 microns, the depth can be 500 microns, and the distance between the turbulent column and the flow channel can be 300 microns); the height of the turbulent column and the depth of the flow channel are consistent, and the diameter of the turbulent column does not contact the inner wall of the flow channel; the medium conveying module of the application is fixedly connected with the support frame through the fixing block (connected with each other through the mounting hole and the nut), a sliding rail is arranged on the fixing block, a sliding block is arranged on the output shaft of the servo motor, the sliding block and the sliding rail are in sliding fit, the output shaft can drive the sliding block to slide back and forth on the sliding rail during the extension and retraction process, a connecting block is fixedly connected on the sliding block, the connecting block is connected with the driving rod of the medium injection pump, one end of the driving rod is provided with a piston, the piston is in sliding fit in the medium storage pipe, so that the driving rod drives the piston to extend and retract to extract and convey the medium in the medium storage pipe according to the sliding of the sliding block; in addition, different media connected with the joints can be provided with peristaltic pumps on the conveying pipeline to realize automatic input action; the innovation of the application lies in that the three module structures are combined to form a complete detection device, realize multi-medium switching input and output, eliminate foam through the reason flow channel to ensure detection accuracy, and concentrate detection and conveying in one set of equipment.
Claims
1. A microfluidic chip-based detection device, characterized in that: The device comprises a medium conveying module, a multi-channel selection valve module and a micro-fluidic chip module; the medium conveying module comprises a medium injection pump and an injection driving motor, the output shaft of the injection driving motor is connected with the driving rod of the medium injection pump to drive the driving rod to extend and retract; the multi-channel selection valve module comprises a multi-channel flow channel seat, a valve seat and a multi-channel valve driving motor, the multi-channel flow channel seat comprises a plurality of medium conveying joints, at least one of the plurality of medium conveying joints is connected with the medium conveying module through a conveying pipeline; the multi-channel flow channel seat is connected with the valve seat, a selection channel seat is arranged in the valve seat, the selection channel seat is driven to rotate by the multi-channel valve driving motor to make two of the plurality of medium conveying joints communicate with each other to realize the input and output of the medium; the micro-fluidic chip module comprises a medium inlet and a medium outlet, the medium inlet and the medium conveying joint are connected with each other through a conveying pipeline, and the medium outlet is connected with a collection device through a conveying pipeline; a micro-fluidic flow channel and a micro-fluidic detection channel that communicate with each other are arranged between the medium inlet and the medium outlet, the micro-fluidic flow channel is used for medium flow and finally enters the micro-fluidic detection channel, and the outlet of the micro-fluidic detection channel is connected with the medium outlet. 2.The microfluidic chip-based detection device according to claim 1, wherein: The medium injection pump is arranged on a fixed base, the medium injection pump comprises a medium storage tube, one end of the driving rod is provided with a piston, the piston is slidingly fitted in the medium storage tube, and the piston slides back and forth along the medium storage tube under the driving of the injection driving motor. 3.The microfluidic chip-based detection device according to claim 1, wherein: The fixed base is provided with a heating sheet and a temperature sensor near the position of the medium storage tube. 4.The microfluidic chip-based detection device according to claim 1, wherein: The fixed base is provided with a fan near the position of the medium storage tube.
5. The microfluidic chip-based detection device of claim 1, wherein: The plurality of medium conveying joints are located at one end of the thickness direction of the multi-channel flow channel seat, a plurality of fine holes are arranged at the opposite end of the thickness direction of the multi-channel flow channel seat, the plurality of fine holes are respectively connected with the plurality of medium conveying joints, and the distribution area of the plurality of fine holes is matched with the end surface area of the selection channel seat. 6.The microfluidic chip-based detection device according to claim 5, wherein: The inner diameter formed by the plurality of fine holes that communicate with the plurality of medium conveying joints is curvedly extended; one of the medium conveying joints is located at the center of the end surface of the multi-channel flow channel seat, and the remaining plurality of medium conveying joints are equidistantly distributed around the center of the medium conveying joint, the arrangement mode of the plurality of fine holes is matched with the arrangement mode of the one medium conveying joint at the center of the end surface and the remaining plurality of medium conveying joints; a groove is arranged on the end surface of the selection channel seat and the multi-channel flow channel seat, and the extension length of the groove is matched with the spacing between the fine hole for communicating with the medium output joint at the center of the end surface and one of the plurality of fine holes for respectively communicating with the plurality of medium conveying joints around.
7. The microfluidic chip-based detection device of claim 5, wherein: The outer wall of the selection channel seat extends a first limiting block protruding radially, and the inner side wall of the valve seat is provided with a second limiting block capable of abutting with the first limiting block; the selection channel seat comprises a first channel seat and a second channel seat connected with each other, the outer diameter of the second channel seat is larger than that of the first channel seat, the groove is arranged on the end face of the first channel seat, and the first limiting block is arranged on the outer wall of the second channel seat; the first channel seat is sleeved with a first bearing, the second channel seat is provided with a containing cavity, the containing cavity is sleeved with a second bearing, and the output shaft of the multi-way valve driving motor penetrates into the channel seat from the shaft hole of the second bearing and is in interference fit with the channel seat; the plurality of medium conveying connectors are in a conical structure, and an anti-skid ring is arranged on the outer wall of the conical structure. 8.The microfluidic chip-based detection device of claim 1, wherein: The microfluidic chip module further comprises a first shell and a second shell connected with each other, the first shell and the second shell are provided with a containing cavity for containing the microfluidic chip, the microfluidic chip is provided with the microfluidic flow channel and the microfluidic detection channel, one end of the microfluidic flow channel is in communication with the medium inlet, and the other end is in communication with the microfluidic detection channel; the medium outlet is in communication with the outlet of the microfluidic detection channel.
9. The microfluidic chip-based detection device of claim 8, wherein: The first shell is located at the upper portion of the second shell, and the microfluidic flow channel faces one side of the second shell; the microfluidic flow channel comprises a flow channel and a plurality of turbulence columns in the flow channel, the outer diameter of the turbulence column is not less than the width of the flow channel, and the two sides of each turbulence column are provided with an expansion flow channel matched with the outer contour of the turbulence column; the flow channel is provided with a plurality of bends to form a plurality of parallel flow channels, and the bending positions of adjacent two flow channels 3031 form a smooth arc bending.
10. The microfluidic chip-based detection device of claim 8, wherein: The microfluidic detection channel is arranged in parallel with the microfluidic flow channel, and the extension depth of the microfluidic flow channel is less than that of the microfluidic detection channel; the first shell is provided with a light source containing hole at one end in the length direction of the microfluidic detection channel, and a detection light source is arranged in the light source containing hole; the first shell and the second shell are provided with a photoelectric sensor at the opposite end in the length direction relative to the light source containing hole, the first shell is provided with a light transmission hole at the corresponding end, and the photoelectric sensor, the light transmission hole and the detection light source are located on the same straight line; the side surface of the microfluidic chip close to the second shell is covered with a light shield cover, and the end surface area of the light shield cover is greater than that of the microfluidic chip covered thereby.