Bubble deceleration ablation structure for micro-fluidic chip

Abstract

The invention relates to a bubble deceleration ablation structure for a micro-fluidic chip, which is characterized by comprising a bubble ablation unit, and the bubble ablation unit is respectively provided with a multi-stage baffling channel, a liquid inlet, an ablation channel, a liquid outlet and a partition wall; the liquid inlet is communicated with liquid inlets of the multiple stages of baffling channels, and more than one flow guide hole is formed in a baffling wall among the multiple stages of baffling channels; a plurality of parallel micro-channels are arranged on the ablation channel along the length direction; the liquid inlet of each micro-channel is communicated with the liquid outlet of the multi-stage baffling channel, and the liquid outlet of each micro-channel is communicated with the liquid outlet; the adjacent micro-channels are separated by partition walls, each partition wall is provided with a plurality of through holes, and the adjacent micro-channels are communicated through the through holes. The device has the advantages that the speed of bubbles can be effectively reduced under the condition that the flow rate of liquid is relatively high, so that the capture rate of the bubbles is improved; and for relatively low liquid flow rate, the resistance can be increased, and the bubble elimination rate is increased.

Description

Technical Field

[0001] This invention relates to a bubble deceleration and ablation structure for microfluidic chips. Background Technology

[0002] Microfluidics, as an emerging technology for manipulating liquid flow at the micrometer scale, has become a research hotspot and key industrialization direction in fields such as biomedicine, chemical analysis, and environmental monitoring due to its core advantages such as low reagent consumption (μL-nL level), fast reaction speed (50%-80% shorter than traditional methods), high integration (enabling integrated sample pretreatment, reaction, and detection), and small size.

[0003] During use, bubbles can easily form in the microchannels of microfluidic technology. These formations can be caused by factors such as sample injection, channel leakage, and gas release due to heat. Since the microchannel size of microfluidic chips is typically in the micrometer range, these tiny bubbles can cause numerous serious problems once they enter the microchannel: Firstly, bubbles can occupy the flow space of the microchannel, causing liquid flow obstruction, unstable flow, and even blockage, affecting the normal operation of the chip. Secondly, the presence of bubbles can interfere with reaction processes within the microchannel (such as biomolecular hybridization and enzymatic reactions) and detection signals (such as fluorescence detection and electrochemical detection), reducing detection accuracy and experimental repeatability. Furthermore, bubbles may impact the inner wall of the microchannel during flow, damaging the chip structure and shortening its lifespan with prolonged use.

[0004] To address the aforementioned problems, various bubble trapping and elimination schemes have emerged in the existing technology. However, these technologies suffer from the following significant drawbacks: 1. Low bubble capture probability: A single through-hole or pitted structure can only intercept bubbles larger than the channel aperture (usually ≥100μm). For small bubbles of 1-100μm, their inertial force with the liquid flow is greater than the surface tension, and they can easily pass directly through the interception structure, resulting in a capture probability of only 60%-70%. 2. Slow degassing speed: Existing technologies rely on the natural rise of bubbles (relying on buoyancy) or diffusion and dissolution (relying on concentration gradient), and the degassing time usually takes 10-30 seconds, which cannot meet the rapid demand for instant detection (requiring a single detection time of ≤15 minutes); 3. Insufficient stability: Some structures are prone to bubble "escape" due to changes in liquid flow pressure, and the channels are prone to blockage after long-term use, affecting the reusability of the device.

[0005] Therefore, developing a bubble capture and elimination structure for microfluidic chips that is simple in structure, easy to process, has high bubble capture efficiency, can effectively eliminate bubbles, has low flow resistance, and is suitable for mass production has become an urgent technical problem to be solved in the field of microfluidic chip technology. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a bubble deceleration and ablation structure for microfluidic chips. When the liquid flow rate is high, it can effectively slow down the speed of bubbles, thereby improving the bubble capture rate; when the liquid flow rate is relatively low, it can increase the resistance and increase the bubble elimination rate.

[0007] To achieve the above objectives, the present invention provides a bubble trapping and elimination structure for microfluidic chips, comprising a bubble ablation unit, wherein the bubble ablation unit is provided with... Multi-stage baffle channels and liquid inlet; the liquid inlet is connected to the liquid inlet of the multi-stage baffle channels, and one or more guide holes are provided on the baffle wall between the multi-stage baffle channels; The ablation channel and liquid outlet are provided; multiple parallel microchannels are provided along the length of the ablation channel; the inlet of each microchannel is connected to the outlet of the multi-stage baffle channel, and the outlet of the microchannel is connected to the liquid outlet. Spacer wall; adjacent microchannels are separated by spacer walls, and several through holes are opened on each spacer wall, and adjacent microchannels are connected through the through holes.

[0008] In this technical solution, the width of the multi-stage baffle channel is 50-500μm, the depth is 20-300μm, and the channel has a turning angle; the length of the multi-stage baffle channel between adjacent turns is 0.1mm-1mm; and the depth of the ablation channel is 20-300μm.

[0009] In this technical solution, the cross-sectional area of ​​each microchannel is 50 μm. 2 -1mm 2 The wall thickness of the baffle wall is 2μm-80μm, and the flow area of ​​the through hole is 1μm. 2 -10000μm 2 .

[0010] In this technical solution, the material of the bubble dissolving unit includes, but is not limited to, polymers, silicon, and glass.

[0011] In this technical solution, the polymer includes, but is not limited to, polydimethylsiloxane, polymethyl methacrylate, polycarbonate, polyimide, or polystyrene; the glass includes, but is not limited to, borosilicate glass or quartz glass.

[0012] In this technical solution, the number of stages of the multi-stage deflection channel (2) is 3-8, and the width and depth of each stage of the deflection channel are consistent.

[0013] The advantages of this invention compared to the prior art are: 1. Significant deceleration effect and high capture efficiency: By setting up multi-stage baffle channels, the fluid is redirected within the baffle channels, generating inertial resistance and fluid shear force, which effectively reduces the flow velocity of bubbles. At the same time, the guide holes on the baffle walls can divert part of the fluid, further disrupting the flow trajectory of the bubbles, enabling them to be captured quickly and avoiding capture failure caused by high-speed bubble flow. This solves the problem of poor bubble deceleration effect in existing structures.

[0014] 2. High ablation efficiency and complete elimination of bubbles: The ablation channel adopts a multi-parallel microchannel design, combined with through holes on the partition wall, so that the bubbles captured by deceleration enter the microchannel and are quickly decomposed into tiny bubbles under the squeezing and shearing action of the fluid, and then merge into the fluid, achieving complete ablation of bubbles and avoiding the impact of bubble accumulation on chip operation. Compared with the existing structure that can only capture bubbles, the ablation effect is greatly improved.

[0015] 3. Stable operation and strong adaptability: The dimensions of each level of baffle channel and microchannel are optimized to ensure smooth fluid flow, no obvious dead volume, and avoid liquid residue and cross-contamination. At the same time, the number and size of the baffle channels and the number and size of the through holes can be adjusted according to actual needs such as bubble size and fluid flow rate to adapt to different microfluidic chip application scenarios, such as biological detection, micro-reaction, cell culture, etc., with strong adaptability.

[0016] 4. No additional energy consumption and high practicality: This invention relies solely on the flow characteristics of the fluid itself to achieve the deceleration and dissolution of bubbles, without the need for additional power or energy, resulting in low operating costs. Furthermore, it does not interfere with the fluid composition or reaction process within the microfluidic chip, making it particularly suitable for biological and chemical experimental scenarios with high requirements for the fluid environment, and thus highly practical. Attached Figure Description

[0017] Figure 1 This is a three-dimensional view of the structure of the rapid bubble dissolution of the present invention; Figure 2 yes Figure 1 Top view.

[0018] Figure 3 This is a perspective view of Embodiment 3 of the present invention; Figure 4 yes Figure 3 The exploded diagram. Detailed Implementation

[0019] It should be noted that the descriptions of these embodiments are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] In the description of this invention, the terms "upper," "lower," "top," and "bottom," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and do not require that this invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms “set up,” “connected,” “located in,” etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, a detachable arrangement, or an integral part; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0022] like Figures 1 to 4 As shown, it is a rapid bubble ablation structure for microfluidics, including a bubble ablation unit 1, on which are respectively provided... Multi-stage baffle channel 2 and liquid inlet 11; the liquid inlet 11 is connected to the liquid inlet of the multi-stage baffle channel 2, and one or more guide holes 3 are provided on the baffle wall 22 between the multi-stage baffle channels 2; The ablation channel 4 and the liquid outlet 12 are provided; multiple parallel microchannels 5 are provided along the length of the ablation channel 4; the inlet of each microchannel 5 is connected to the outlet of the multi-stage baffle channel 2, and the outlet of the microchannel 5 is connected to the liquid outlet 12. Spacer 51; adjacent microchannels 5 are separated by spacer 51, and several through holes 6 are provided on each spacer 51, and adjacent microchannels 5 are connected by through holes 6.

[0023] In this embodiment, the multi-stage baffle channel 2 has a width of 50-500μm and a depth of 20-300μm, and the channel has a turning angle; the length of the multi-stage baffle channel 2 between adjacent turns is 0.1mm-1mm; the depth of the ablation channel 4 is 20-300μm.

[0024] In this embodiment, the cross-sectional area of ​​each microchannel 5 is 50 μm. 2 -1mm 2 The wall thickness of the baffle wall 51 is 2μm-80μm, and the flow area of ​​the through hole 6 is 1μm. 2 -10000μm 2 .

[0025] In this embodiment, the material of the bubble dissolving unit 1 includes, but is not limited to, polymers, silicon, and glass.

[0026] In this embodiment, the polymer includes, but is not limited to, polydimethylsiloxane, polymethyl methacrylate, polycarbonate, polyimide, or polystyrene; the glass includes, but is not limited to, borosilicate glass or quartz glass.

[0027] In this embodiment, the multi-stage deflection channel 2 has 3-8 stages, and the width and depth of each stage of the deflection channel are consistent.

[0028] 1. Significant deceleration effect and high capture efficiency: By setting up multi-stage baffle channels, the fluid is redirected within the baffle channels, generating inertial resistance and fluid shear force, which effectively reduces the flow velocity of bubbles. At the same time, the guide holes on the baffle walls can divert part of the fluid, further disrupting the flow trajectory of the bubbles, enabling them to be captured quickly and avoiding capture failure caused by high-speed bubble flow. This solves the problem of poor bubble deceleration effect in existing structures.

[0029] 2. High ablation efficiency and complete elimination of bubbles: The ablation channel adopts a multi-parallel microchannel design, combined with through holes on the partition wall, so that the bubbles captured by deceleration enter the microchannel and are quickly decomposed into tiny bubbles under the squeezing and shearing action of the fluid, and then merge into the fluid, achieving complete ablation of bubbles and avoiding the impact of bubble accumulation on chip operation. Compared with the existing structure that can only capture bubbles, the ablation effect is greatly improved.

[0030] 3. Stable operation and strong adaptability: The dimensions of each level of baffle channel and microchannel are optimized to ensure smooth fluid flow, no obvious dead volume, and avoid liquid residue and cross-contamination. At the same time, the number and size of the baffle channels and the number and size of the through holes can be adjusted according to actual needs such as bubble size and fluid flow rate to adapt to different microfluidic chip application scenarios, such as biological detection, micro-reaction, cell culture, etc., with strong adaptability.

[0031] 4. No additional energy consumption and high practicality: This invention relies solely on the flow characteristics of the fluid itself to achieve the deceleration and dissolution of bubbles, without the need for additional power or energy, resulting in low operating costs. Furthermore, it does not interfere with the fluid composition or reaction process within the microfluidic chip, making it particularly suitable for biological and chemical experimental scenarios with high requirements for the fluid environment, and thus highly practical.

[0032] Example 1

[0033] like Figures 1 to 4 As shown, it is a rapid bubble ablation structure for microfluidics, including a bubble ablation unit 1. The bubble ablation unit 1 is made of polydimethylsiloxane (PDMS), which has good biocompatibility, air permeability and ease of processing, and is suitable for microfluidic chips for biological detection.

[0034] The bubble ablation unit 1 is provided with a multi-stage baffle channel 2, a liquid inlet 11, an ablation channel 4, a liquid outlet 12, and a partition wall 51. The liquid inlet 11 is connected to the liquid inlet of the multi-stage baffle channel 2 and is used to introduce the fluid containing bubbles into the multi-stage baffle channel 2. The multi-stage baffle channel 2 has 5 stages, each with a width of 200 μm and a depth of 150 μm. The turning angle of the channel is 90°, and the length of the multi-stage baffle channel 2 between adjacent turns is 0.5 mm, ensuring that the fluid generates sufficient inertial resistance when turning in the channel, so as to effectively decelerate the bubbles. Two guide holes 3 with a diameter of 50 μm are provided on the baffle wall 22 between the multi-stage baffle channels 2. The guide holes 3 are used to divert part of the fluid, disrupt the flow trajectory of the bubbles, and improve the bubble capture efficiency.

[0035] The ablation channel 4 has a depth of 150 μm, which is consistent with the depth of the multi-stage baffle channel 2, ensuring a smooth fluid transition and avoiding secondary bubbles caused by abrupt changes in channel depth. Four parallel microchannels 5 are provided along the length of the ablation channel 4. Each microchannel 5 has a rectangular cross-section with a cross-sectional area of ​​200 μm × 150 μm = 30000 μm². The inlet of each microchannel 5 is connected to the outlet of the multi-stage baffle channel 2, and the outlet of the microchannel 5 is connected to the liquid outlet 12, which is used to export the fluid after ablation of bubbles.

[0036] Adjacent microchannels 5 are separated by a partition wall 51 with a wall thickness of 20 μm. Each partition wall 51 has 4 through holes 6 with a flow area of ​​100 μm². Adjacent microchannels 5 are connected by the through holes 6, allowing the fluid in the microchannels 5 to flow to each other. The fluid's squeezing and shearing action accelerates the dissolution of bubbles.

[0037] The working process of this embodiment is as follows: Fluid containing bubbles enters the multi-stage baffle channel 2 through the liquid inlet 11. Within the multi-stage baffle channel 2, the fluid changes direction multiple times, generating inertial resistance and fluid shear force, significantly reducing the flow velocity of the bubbles. At the same time, the guide holes 3 on the baffle wall 22 divert part of the fluid, further disrupting the flow trajectory of the bubbles and allowing them to be quickly captured. Subsequently, the fluid containing bubbles enters the multiple microchannels 5 of the ablation channel 4. Under the constraint of the microchannels 5, the fluid flow rate is further stabilized, and the bubbles gradually break down under the squeezing and shearing action of the fluid. Meanwhile, the through holes 6 on the partition wall 51 allow the fluid in adjacent microchannels 5 to circulate with each other, causing the bubbles to quickly decompose into tiny bubbles and merge into the fluid, achieving complete ablation of the bubbles. The fluid after bubble ablation is collected through the outlet of the microchannel 5 to the liquid outlet 12 and exported to the subsequent channels of the microfluidic chip, ensuring the stable operation of the microfluidic chip.

[0038] Example 2 The difference between this embodiment and Embodiment 1 is that: the bubble ablation unit 1 is made of borosilicate glass, which is suitable for microfluidic chip scenarios with high requirements for high temperature resistance and chemical corrosion resistance; the multi-stage baffle channel 2 has 3 stages, a width of 50μm, a depth of 30μm, and a length between adjacent bends of 0.1mm; the baffle wall 22 is provided with a flow guide hole 3 with a diameter of 10μm; the ablation channel 4 has a depth of 30μm and is provided with 2 parallel microchannels 5, each microchannel 5 having a cross-sectional area of ​​50μm²; the partition wall 51 has a wall thickness of 2μm; each partition wall 51 has 2 through holes 6 with a flow area of ​​1μm².

[0039] The working principle of this embodiment is the same as that of embodiment 1. It achieves bubble deceleration and capture through multi-stage baffle channels and achieves efficient bubble ablation through microchannels and through holes. It is suitable for microfluidic chip scenarios with small microchannel size and slow fluid flow rate, such as microchemical analysis chips.

[0040] Example 3 like Figure 3 and Figure 4 The microfluidic chip shown includes a substrate 8 and a cover plate 7. The substrate 8 is provided with a bubble ablation unit 1, a culture chamber 9, a liquid inlet, a liquid outlet, and a sample outlet channel 10. The cover plate 7 covers the substrate 6 and is provided with a liquid inlet 81 and a liquid outlet 82. The liquid inlet 81 is connected to the liquid inlet, and the liquid inlet is connected to the culture chamber 8 through the bubble ablation unit 1. The culture chamber 9 is connected to the liquid outlet through the sample outlet channel 10, and the liquid outlet is connected to the liquid outlet 72. In this embodiment, the bubble ablation unit 1 is made of polydimethylsiloxane (PDMS), which has good biocompatibility and air permeability, avoiding adverse effects on cell culture. The structure of the bubble ablation unit 1 is the same as in Embodiment 1. The multi-level baffle channel 2 has 5 levels, a width of 200μm, a depth of 150μm, a turning angle of 90°, and a length of 0.5mm between adjacent turning points. The baffle wall 22 is provided with two guide holes 3 with a diameter of 50μm. The ablation channel 4 has a depth of 150μm and is provided with four parallel microchannels 5. The cross-sectional area of ​​the microchannel 5 is 30000μm². The wall thickness of the partition wall 51 is 20μm, and each partition wall 51 is provided with four through holes 6 with a flow area of ​​100μm².

[0041] The culture tank 9 measures 5mm × 5mm × 0.3mm, with a hydrophilic inner wall to facilitate cell adhesion and growth and uniform distribution of nutrient solution. The inlet and outlet holes are both 1mm in diameter and are sealed to the inlet 81 and outlet 72 to prevent air and liquid leakage. The sample outlet channel 10 is 300μm wide and 150μm deep to ensure smooth discharge of the cultured cell suspension or nutrient solution without residue.

[0042] The working process of this embodiment is as follows: The nutrient solution required for cell culture is selected from conventional cell culture suitable types in the art. The specific type can be adjusted according to the type of cells to be cultured. For example, DMEM medium (with 10% fetal bovine serum and 1% penicillin-streptomycin) can be used for tumor cell culture, and mesenchymal stem cell culture medium (with basal culture medium, serum substitute and cell growth factors) can be used for stem cell culture. The nutrient solution enters the inlet hole through the inlet 81 on the cover plate 7 and then flows into the bubble ablation unit 1. The bubbles entrained in the nutrient solution are slowed down and captured in the multi-stage baffle channel 2, and then broken and ablated through the microchannel 5 of the ablation channel 4 to ensure that the nutrient solution entering the culture pool 9 is free from bubble interference. After the nutrient solution enters the culture pool 9, it provides a stable growth environment for the cells. A small number of metabolic bubbles generated during the dynamic cell culture process can be completely ablated by re-entering the bubble ablation unit 1 with the nutrient solution circulation. After the culture is completed, the cell suspension or waste nutrient solution enters the outlet hole through the outlet channel 10 and is then discharged through the outlet 72 to complete the entire dynamic cell culture process.

[0043] The advantage of this embodiment is that by integrating the bubble ablation unit 1 with the cell dynamic culture chip, it effectively solves problems such as localized fluid deficiency, cell death, and unstable nutrient solution flow caused by bubbles during cell culture, ensuring the continuity and stability of cell culture. At the same time, the nutrient solution can be flexibly adjusted according to the specific cell type being cultured, adapting to various cell dynamic culture scenarios, such as tumor cell culture, stem cell expansion, and primary cell culture, making it more practical and without adversely affecting cell activity.

[0044] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations of these embodiments without departing from the principles and spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A bubble deceleration and ablation structure for microfluidic chips, characterized in that... Includes a bubble ablation unit (1), on which are respectively provided Multi-stage baffle channel (2) and liquid inlet (11); the liquid inlet (11) is connected to the liquid inlet of the multi-stage baffle channel (2), and one or more guide holes (3) are provided on the baffle wall (22) between the multi-stage baffle channels (2); Ablation channel (4) and liquid outlet (12); multiple parallel microchannels (5) are provided along the length direction of the ablation channel (4); the inlet of each microchannel (5) is connected to the outlet of the multi-stage baffle channel (2), and the outlet of the microchannel (5) and the liquid outlet (12) are connected. Spacer wall (51); adjacent microchannels (5) are separated by spacer wall (51), and several through holes (6) are provided on each spacer wall (51), and adjacent microchannels (5) are connected by through holes (6).

2. The bubble deceleration and ablation structure for microfluidic chips according to claim 1, characterized in that... The multi-stage baffle channel (2) has a width of 50-500μm and a depth of 20-300μm, and the channel has a turning angle; the length of the multi-stage baffle channel (2) between adjacent turning angles is 0.1mm-1mm; the depth of the ablation channel (4) is 20-300μm.

3. The bubble deceleration and ablation structure for microfluidic chips according to claim 1, characterized in that... Each of the microchannels (5) has a cross-sectional area of ​​50 μm. 2 -1mm 2 The wall thickness of the baffle wall (51) is 2μm-80μm, and the flow area of ​​the through hole (6) is 1μm. 2 -10000μm 2 .

4. The bubble trapping and elimination structure for microfluidic chips according to claim 1, characterized in that... The bubble dissolving unit (1) is made of materials including but not limited to polymers, silicon, and glass.

5. The bubble trapping and elimination structure for microfluidic chips according to claim 4, characterized in that... The polymers include, but are not limited to, polydimethylsiloxane, polymethyl methacrylate, polycarbonate, polyimide, or polystyrene; the glass includes, but is not limited to, borosilicate glass or quartz glass.

6. The bubble deceleration and ablation structure for microfluidic chips according to claim 1, characterized in that... The multi-stage deflection channel (2) has 3–8 stages, and the width and depth of each stage of the deflection channel are consistent.

Images