Automatic sampling device and method

Abstract

The invention belongs to the microfluidic technology, and particularly relates to an automatic sample injection device and method.The automatic sample injection device comprises a bearing seat, and the bearing seat is provided with a bearing position allowing a microfluidic chip to be clamped in; the pressing block is arranged on the bearing seat through a rotating shaft, and the fixing unit is used for fixing the pressing block on the bearing seat and releasing the pressing block, so that when the pressing block extrudes the micro-fluidic chip, a first channel of the pressing block is communicated with a second channel of the micro-fluidic chip; the sampling needle and the ventilation component are respectively fixed on the moving unit; the moving unit is used for driving the sample adding needle and the ventilation component, so that the sample adding needle adds liquid into the first channel, and the ventilation component is communicated with the first channel. The method has the advantages of automation, no need of manual intervention and the like.

Description

Technical Field

[0001] The invention relates to microfluidic technology, and in particular to an automatic sampling device and method. Background Art

[0002] As an important branch in the research of microfluidic chips, droplet microfluidics is a non-continuous flow microfluidic technology that uses two immiscible liquid phases to produce dispersed microdroplets for experimental operations. In microfluidic chips, droplets are formed by the combined action of surface tension and shear force at the interface of the two phases. According to the difference between the dispersed phase and the continuous phase, droplets can be divided into two types: water phase droplets in the oil phase (W / O type droplets) and oil phase droplets in the water phase (O / W type droplets). Droplet microfluidics realizes the flow control of droplets in tiny channels, building a new platform for biological and medical research.

[0003] Microdroplets have the characteristics of small size, large specific surface area, fast speed, high flux, uniform size, closed system, and internal stability. They have important applications in the fields of drug controlled release, virus detection, particle material synthesis, catalysts, etc., and have been widely used in the analysis and detection of biological macromolecules such as DNA, proteins, and enzymes, as well as in biomedical fields such as drug delivery.

[0004] The existing microfluidic chip sampling device adopts manual sampling, specifically, the pipeline is inserted into the chip device, the sample, oil, and substrate are placed in their respective bottles, one end is connected to the bottle and the chip device through three pipelines, and the other end is connected to the bottle and the air pump device through three pipelines, and then the air pump is turned on to pass the sample, oil, and substrate into the chip for droplet generation. When the droplet generation detection is completed, the pipeline is unplugged to generate the next sample.

[0005] This manual injection method is cumbersome to operate and is not suitable for large-volume sample droplet generation and detection. Summary of the invention

[0006] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides an automatic sample injection device.

[0007] The objective of the present invention is achieved through the following technical solutions: An automatic sample injection device comprises a bearing seat, wherein the bearing seat has a bearing position allowing a microfluidic chip to be inserted; the automatic sample injection device further comprises: A pressing block and a fixing unit, wherein the pressing block is arranged on the supporting seat via a rotating shaft, and the fixing unit is used to fix the pressing block on the supporting seat and release the pressing block, so that when the pressing block presses the microfluidic chip, the first channel of the pressing block is connected to the second channel of the microfluidic chip; A sample adding needle and a ventilation component, wherein the sample adding needle and the ventilation component are respectively fixed on the moving unit; A moving unit is used to drive the sample adding needle and the ventilation component, so that the sample adding needle adds liquid into the first channel and the ventilation component is connected with the first channel.

[0008] The present invention also provides an automatic sampling method, and the object of the invention is achieved through the following technical solutions: An automatic sampling method comprises the following steps: Insert the microfluidic chip into the carrier; Rotating the pressing block so that the pressing block squeezes the microfluidic chip, the first channel in the pressing block is connected to the second channel in the microfluidic chip, and the pressing block is fixed; The moving unit drives the sample adding needle so that the sample adding needle adds liquid into the first channel; The moving unit drives the ventilation component so that the ventilation component is connected to the first channel, and the gas drives the liquid in the first channel to pass through the first channel and the second channel and enter the microfluidic chip.

[0009] Compared with the prior art, the present invention has the following beneficial effects: The mobile unit is used to control the sample injection needle and ventilation components, realize automatic sample injection and liquid transmission, thereby realizing fully automatic injection of microfluidic chips, stably generating tiny droplets within 10μm, avoiding manual operation and improving work efficiency; It reduces chip contamination caused by external impurities introduced due to manual operation, thus avoiding chip clogging and extending the chip service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The disclosure of the present invention will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. In the drawings: Figure 1 It is a schematic structural diagram of the automatic sample injection device of the present invention; Figure 2 It is a partial structural schematic diagram of the automatic sample injection device of the present invention; Figure 3 It is a schematic cross-sectional view of the microfluidic chip, the pressing block and the ventilation component of the present invention; Figure 4 is a schematic diagram of the optical detection results of the micro-droplets produced by the present invention; Figure 5 It is a schematic diagram of the optical detection results of the micro-droplets produced by the present invention.

[0011] In the accompanying drawings, 9-rotating shaft, 11-carrying seat, 12-pressing block, 121-first channel, 122-protrusion, 1211-first sub-channel, 1212-second sub-channel, 1213-third sub-channel, 21-microfluidic chip, 22-second channel, 30-carrying plate, 31-moving unit, 310-bracket, 32-ventilation component, 33-sample adding needle, 34-motor, 35-driving wheel, 36-driven wheel, 37-synchronous belt, 38-moving part, 39-vertical transmission mechanism, 61-sealing member, 81-fixed unit. DETAILED DESCRIPTION

[0012] Figure 1-Figure 5 The following description describes optional specific embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to teach the technical solution of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will understand that variations or replacements derived from these specific embodiments will be within the scope of the present invention. Those skilled in the art will understand that the following features can be combined in various ways to form multiple variations of the present invention. Thus, the present invention is not limited to the following optional specific embodiments, but is only limited by the claims and their equivalents.

[0013] Example 1.

[0014] An automatic sampling device, such as Figure 1 As shown, including: The supporting seat 11 has a supporting position for allowing the microfluidic chip 21 to be inserted therein.

[0015] like Figure 2 As shown, the pressing block 12 is arranged on the supporting seat 11 through the rotating shaft 9, and the fixing unit 81 is used to fix the pressing block 12 on the supporting seat 11 so that the pressing block 12 squeezes the microfluidic chip 21, and releases the pressing block 12.

[0016] like Figure 3 As shown, when the pressing block 12 presses the microfluidic chip 21 , the first channel 121 of the pressing block 12 is connected to the second channel 22 of the microfluidic chip 21 .

[0017] The sample addition needle 33 and the ventilation component 32 are respectively fixed on the moving unit 31.

[0018] The moving unit 31 is used to drive the sample adding needle 33 and the ventilation component 32 , so that the sample adding needle 33 adds liquid into the first channel 121 , and the ventilation component 32 is connected to the first channel 121 .

[0019] In order to compact the microfluidic chip 21 and realize the communication of the internal channels, further, as Figure 3As shown, the bottom end of the pressing block 12 has a plurality of protrusions 122 , and the first channel 121 passes through the pressing block 12 and the protrusions 122 .

[0020] In order to achieve sealing, further, as Figure 3 As shown, the upper end of the pressing block 12 has an annular groove surrounding the opening of the first channel 121, and the sealing member 61 is arranged in the annular groove; the projection of the bottom end of the ventilation component 32 on the horizontal plane and the projection of the sealing member 61 on the horizontal plane have an annular overlapping area.

[0021] In order to temporarily store liquid, further, the first channel 121 includes a first sub-channel 1211, a second sub-channel 1212 and a third sub-channel 1213 which are arranged in sequence from top to bottom and connected, and the inner diameter of the first sub-channel 1211 is larger than that of the second sub-channel 1212. From top to bottom, the inner diameter of the second sub-channel 1212 gradually decreases, and the inner diameter of the third sub-channel 1213 is equal to the minimum inner diameter of the second sub-channel 1212.

[0022] In order to generate droplets that meet the requirements, further, The gas pressure P in the ventilation component 32 satisfies: , γ is the sample interfacial tension, L and r are the channel length and radius in the microfluidic chip 21, respectively, R is the radius of the first subchannel 1211, h is the height of the first subchannel 1211, n is the number of microdroplets generated per second, t is the time for generating microdroplets, and P0 is the atmospheric pressure.

[0023] An automatic sampling method according to an embodiment of the present invention, that is, a working method of the sampling device according to this embodiment, comprises the following steps: Insert the microfluidic chip 21 into the carrier position; The pressing block 12 is rotated so that the pressing block 12 squeezes the microfluidic chip 21, and the first channel 121 in the pressing block 12 is connected with the second channel 22 in the microfluidic chip 21, thereby fixing the pressing block 12; The moving unit 31 drives the sample adding needle 33 so that the sample adding needle 33 adds liquid into the first channel 121; The moving unit 31 drives the ventilation component 32 so that the ventilation component 32 is connected to the first channel 121 , and the gas drives the liquid in the first channel 121 to pass through the first channel 121 and the second channel 22 and enter the microfluidic chip 21 .

[0024] Example 2.

[0025] An application example of the automatic sampling device and method in Example 1 of the present invention.

[0026] In this application example, Figure 1As shown, the mobile unit 31 comprises a left and right transmission mechanism and a vertical transmission mechanism 39. The left and right transmission mechanisms comprise a driving wheel 35, a driven wheel 36 and a moving member 38 driven by a motor 34, wherein the motor 34, the driving wheel 35 and the driven wheel 36 are all fixed on the bracket 310, a synchronous belt 37 is wound around the driving wheel 35 and the driven wheel 36, and the moving member 38 is arranged on the slide rail and connected with the synchronous belt 37. The rotation of the motor 34 is converted into the left and right translation of the moving member 38. The vertical transmission mechanism 39 is arranged on the left and right transmission mechanisms, and adopts the same mechanism as the left and right transmission mechanisms, except that the moving directions provided are different. The ventilation component 32 and the sample adding needle 33 are fixed on the carrier plate 30, and the carrier plate 30 is fixed on the vertical transmission mechanism 39.

[0027] like Figure 2 As shown, the upper side of the support seat 11 has a positioning groove that allows the microfluidic chip 21 to be inserted. The pressing block 12 is arranged on the upper side of the support seat 11 through the rotating shaft 9, and is used to press the microfluidic chip 21. The pressing block 12 is fixed to the support seat 11 and released by a snap-fit ​​fixing unit 81. The fixing unit 81 of this embodiment adopts a combination of a torsion spring and a snap.

[0028] like Figure 3 As shown, the bottom end of the pressing block 12 has a plurality of protrusions 122, and the protrusions 122 are used to press the microfluidic chip 21. The pressing block 12 has a first channel 121 that runs through it, specifically including a first subchannel 1211, a second subchannel 1212, and a third subchannel 1213 that are sequentially arranged and connected from top to bottom, the inner diameter of the first subchannel 1211 is larger than the second subchannel 1212, and the inner diameter of the second subchannel 1212 gradually decreases from top to bottom, and the inner diameter of the third subchannel 1213 is equal to the minimum inner diameter of the second subchannel 1212. The third subchannel 1213 runs through the protrusion 122 and is connected to the second channel 22 of the microfluidic chip 21.

[0029] The gas pressure P in the ventilation component 32 satisfies: , γ is the sample interfacial tension, L and r are the channel length and radius in the microfluidic chip 21, respectively, R is the radius of the first subchannel 1211, h is the height of the first subchannel 1211, n is the number of microdroplets generated per second, t is the time for generating microdroplets, P0 is the atmospheric pressure, and all parameters are in international units.

[0030] The upper end of the pressing block 12 has an annular groove surrounding the opening of the first channel 121 , and a sealing member (O-ring) 61 is disposed in the annular groove.

[0031] An automatic sampling method according to an embodiment of the present invention, that is, a working method of the sampling device according to this embodiment, comprises the following steps: Insert the microfluidic chip 21 into the positioning groove; The pressing block 12 is rotated around the rotating shaft 9 so that the protrusion 122 of the pressing block 12 squeezes the microfluidic chip 21, and the first channel 121 in the pressing block 12 is connected with the second channel 22 in the microfluidic chip 21, and the pressing block 12 is fixed by the fixing unit 81; The moving unit 31 drives the sample adding needle 33 in the left-right direction and the vertical direction, so that the sample adding needle 33 adds liquid into the first channel 121; The moving unit 31 drives the ventilation component 32 in the left-right direction and the vertical direction, so that the bottom end of the ventilation component 32 squeezes the sealing member 61 to achieve sealing. At the same time, the ventilation component 32 is connected to the first channel 121, and the gas drives the liquid in the first channel 121 to pass through the first channel 121 and the second channel 22 and enter the microfluidic chip 21, thereby forming micro droplets.

[0032] The parameters of this embodiment are: n=100,000 / second, t=250 seconds, the diameter R of the first subchannel 1211 is 1.25 mm, the height h is 4 mm, γ=40 mN / m, L=1 m, r=300 μm. The minimum value of pressure P is 200 kPa, and the pressure P is 200 kPa. The radius r1 of the microdroplet satisfies , r1=5μm is obtained.

[0033] The fluorescent signal of the generated microdroplets is detected using optical detection techniques, such as Figure 4 As shown, the fluorescence signal can be completely distinguished from the background signal and conforms to the Gaussian distribution.

[0034] Example 3.

[0035] According to the application example of the automatic sampling device and method in Example 1 of the present invention, the difference from Example 2 is that: n=100,000 / second, t=73 seconds, the diameter R of the first subchannel 1211 is 1 mm, the height h is 6.25 mm, γ=40 mN / m, L=1 m, r=200 μm. The minimum value of pressure P is 360 kPa, and the pressure P is 360 kPa. The radius r1 of the microdroplet satisfies , r1=3.5μm was obtained.

[0036] The fluorescent signal of the generated microdroplets is detected using optical detection techniques, such as Figure 5 As shown, the fluorescence signal can be completely distinguished from the background signal and conforms to the Gaussian distribution.

Claims

1. An automatic sample injection device, comprising a carrier seat, wherein the carrier seat has a carrier position allowing a microfluidic chip to be inserted; characterized in that: The automatic sample injection device also includes: A pressing block and a fixing unit, wherein the pressing block is arranged on the supporting seat via a rotating shaft, and the fixing unit is used to fix the pressing block on the supporting seat and release the pressing block, so that when the pressing block presses the microfluidic chip, the first channel of the pressing block is connected to the second channel of the microfluidic chip; A sample adding needle and a ventilation component, wherein the sample adding needle and the ventilation component are respectively fixed on the moving unit; A moving unit is used to drive the sample adding needle and the ventilation component, so that the sample adding needle adds liquid into the first channel and the ventilation component is connected with the first channel.

2. The automatic sample introduction device according to claim 1, characterized in that: The bottom end of the pressing block has a plurality of protrusions, and the first channel runs through the pressing block and the protrusions.

3. The automatic sample introduction device according to claim 1, characterized in that: The upper end of the pressing block has an annular groove surrounding the first channel opening, and a sealing member is arranged in the annular groove; the projection of the bottom end of the ventilation component on the horizontal plane and the projection of the sealing member on the horizontal plane have an annular overlapping area.

4. The automatic sample introduction device according to claim 1, characterized in that: The first channel includes a first sub-channel, a second sub-channel and a third sub-channel which are arranged in sequence from top to bottom and connected. The inner diameter of the first sub-channel is larger than that of the second sub-channel. From top to bottom, the inner diameter of the second sub-channel gradually decreases, and the inner diameter of the third sub-channel is equal to the minimum inner diameter of the second sub-channel.

5. The automatic sample introduction device according to claim 4, characterized in that: The gas pressure P in the ventilation component satisfies: , γ is the sample interfacial tension, L and r are the length and radius of the channel in the microfluidic chip, respectively, R is the radius of the first subchannel, h is the height of the first subchannel, n is the number of microdroplets generated per second, t is the time for generating microdroplets, and P0 is the atmospheric pressure.

6. An automatic sampling method comprising the following steps: Insert the microfluidic chip into the carrier; Rotating the pressing block so that the pressing block squeezes the microfluidic chip, the first channel in the pressing block is connected to the second channel in the microfluidic chip, and the pressing block is fixed; The moving unit drives the sample adding needle so that the sample adding needle adds liquid into the first channel; The moving unit drives the ventilation component so that the ventilation component is connected to the first channel, and the gas drives the liquid in the first channel to pass through the first channel and the second channel and enter the microfluidic chip.

7. The automatic sampling method according to claim 6, characterized in that: The bottom end of the pressing block has a plurality of protrusions, the first channel runs through the pressing block and the protrusions, and the microfluidic chip is squeezed between the protrusions and the supporting seat.

8. The automatic sampling method according to claim 6, characterized in that: The upper end of the pressing block has an annular groove surrounding the first channel opening, and a sealing member is arranged in the annular groove; the projection of the bottom end of the ventilation component on the horizontal plane and the projection of the sealing member on the horizontal plane have an annular overlapping area.

9. The automatic sampling method according to claim 6, characterized in that: The first channel includes a first sub-channel, a second sub-channel and a third sub-channel which are arranged in sequence from top to bottom and connected. The inner diameter of the first sub-channel is larger than that of the second sub-channel. From top to bottom, the inner diameter of the second sub-channel gradually decreases, and the inner diameter of the third sub-channel is equal to the minimum inner diameter of the second sub-channel.

10. The automatic sampling method according to claim 9, characterized in that: The gas pressure P in the ventilation component satisfies: , γ is the sample interfacial tension, L and r are the length and radius of the channel in the microfluidic chip, respectively, R is the radius of the first subchannel, h is the height of the first subchannel, n is the number of microdroplets generated per second, t is the time for generating microdroplets, and P0 is the atmospheric pressure.

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