A microfluidic biological sample detection chip with integrated pumping and micromixing functions

Abstract

A microfluidic biological sample detection chip with integrated pumping and micro-mixing functions relates to a microfluidic biological sample detection chip. The present invention aims to solve the technical problem that a long mixing time is often required to achieve a good mixing effect of the fluid in the existing microfluidic biological sample detection chip. The present invention proposes a microfluidic biological sample detection chip, which can accurately and conveniently control the flow of sample reagents, achieve efficient mixing and pumping of samples with fluorescent microspheres or magnetic beads, and further achieve efficient and high-precision detection of biological samples. Different from the water-absorbing fiber and capillary drive mode of traditional antigen detection kits and chips, the present invention utilizes a piezoelectric drive mode to achieve the functional integration of liquid pumping and micro-mixing in the same pump cavity or the same structural unit, so that biological reagents can be quantitatively pumped from the inlet to the sample detection channel, while enabling the reagents to be fully mixed with the fluorescent microspheres or magnetic beads, thereby achieving efficient integration of structure and function.

Description

Technical Field

[0001] The invention relates to a microfluidic biological sample detection chip. Background Art

[0002] The quantitative delivery and efficient mixing of trace samples are essential steps in many biomedical testing and chemical analysis processes. In the past, biological or chemical analysis and testing, such as antigen detection, drug screening, and clinical symptom analysis, were mainly completed manually. However, due to the complexity of the operation process, completing all operations required excessive manpower and time costs. Although the emergence of automated workstations has improved the efficiency of analysis to a certain extent, the operation is complicated and the cost is high. Therefore, microfluidic chips with low sample consumption, fast detection speed, and high degree of integration have shown significant advantages, playing an increasingly important role in protein detection, nucleic acid research, cell culture, antigen detection, etc., and have broad application prospects.

[0003] In recent years, due to the unique advantages of piezoelectric pumping in fluid transport (compact structure, low power consumption, high power density, high precision, fast response, low noise, and no electromagnetic interference), more and more researchers have begun to use piezoelectric pumping as the driving source for microfluidic systems. Efficient mixing is the foundation for sample detection. Because the flow channel dimensions of microfluidic chips are at the micro-nano level, the fluid Reynolds number is very low, and the flow state is laminar, the mixing of fluids mainly relies on intermolecular diffusion. Achieving good mixing often requires a long mixing time. Acoustic field-driven microbubble vibration mixers use vibrating microbubbles as a power source. The equipment required to achieve rapid mixing of flowing liquids is simple, and they do not introduce other impurities into the liquid, reducing sample contamination. They are not affected by acoustic and thermal effects, thus ensuring the initial state of sample reagents. Compared with other mixing methods, mixing efficiency is also higher. Summary of the Invention

[0004] The present invention aims to solve the technical problem that a long mixing time is often required to achieve a good mixing effect of fluids in existing microfluidic biological sample detection chips, and to provide a microfluidic biological sample detection chip with integrated pumping and micro-mixing functions.

[0005] The microfluidic biological sample detection chip with integrated pumping and micro-mixing functions of the present invention is composed of a chip body 1, a piezoelectric ceramic buzzer 2 and a sealing cover 3;

[0006] The piezoelectric ceramic buzzer 2 is composed of a cylindrical piezoelectric ceramic piece 2-1 at the upper end and a cylindrical copper substrate 2-2 at the lower end. The diameter of the cylindrical piezoelectric ceramic piece 2-1 is smaller than that of the cylindrical copper substrate 2-2. The centers of the cylindrical piezoelectric ceramic piece 2-1 and the cylindrical copper substrate 2-2 are on the same vertical line.

[0007] The upper surface of the sealing cover plate 3 is provided with a stepped through hole 3-1. The inner diameter of the upper end of the stepped through hole 3-1 is smaller. The stepped through hole 3-1 cooperates with the outer wall of the piezoelectric ceramic buzzer 2 for positioning. The sealing cover plate 3 is a quadrangular pyramid structure with a longer side length on the upper surface.

[0008] The chip body 1 is composed of an outer frame 1-17 and an inner cavity 1-13, the upper surface of the inner cavity 1-13 is lower than the upper surface of the outer frame 1-17; a circle of sealing strips 1-15 is provided near the edge of the upper surface of the inner cavity 1-13, and the sealing strips 1-15 are lower than the outer frame 1-17; the solution inlet 1-1, the first filter area 1-2, the inlet cone area 1-3, the pump cavity 1-4, the outlet cone area 1-6, the second filter area 1-7, the exhaust flow channel 1-9, the sample detection channel 1-10, the waste liquid pool 1-11 and the waste liquid outlet 1-12 are arranged in sequence in the inner cavity 1-13 in the sealing strip 1-15 and are all lower than the inner cavity 1-13; in the chip body 1 In the length direction, a sample solution inlet 1-1 is set near one end, and the solution inlet 1-1 is a through hole; the first filter area 1-2 is connected to the solution inlet 1-1, and a plurality of cylindrical micro-pillars 1-14 arranged in an array are vertically set in the first filter area 1-2, and the cylindrical micro-pillars 1-14 are at the same height as the inner cavity 1-13; the inlet cone tube area 1-3 is connected to the first filter area 1-2, and the vertical cross-sectional area of the inlet cone tube area 1-3 gradually decreases toward the direction of the first filter area 1-2, and the pump cavity 1-4 is connected to the end with the larger vertical cross-sectional area of the inlet cone tube area 1-3, and a plurality of blind holes 1-5 arranged in an array are set on the bottom surface of the pump cavity 1-4, and the inner wall of the blind hole 1-5 The top is coated with a hydrophobic coating, and the bottom surface of the pump chamber 1-4 is coated with polystyrene fluorescent microspheres or magnetic beads; the outlet cone pipe area 1-6 is connected to the pump chamber 1-4, and the vertical cross-sectional area of the outlet cone pipe area 1-6 gradually decreases toward the pump chamber 1-4; the second filter area 1-7 is connected to the end with the larger vertical cross-sectional area of the outlet cone pipe area 1-6, and a plurality of cylindrical micro-pillars 1-14 arranged in an array are vertically arranged in the second filter area 1-7, and the cylindrical micro-pillars 1-14 are at the same height as the inner cavity 1-13; the sample detection channel 1-10 is connected to the second filter area 1-7, and is connected to an exhaust flow channel 1-9 on both sides of the sample detection channel 1-10, and the exhaust flow channel 1-9 The end is an exhaust hole 1-8, and the exhaust hole 1-8 is a through hole; the waste liquid pool 1-11 is connected to the sample detection channel 1-10, and the waste liquid outlet 1-12 is arranged on the side of the waste liquid pool 1-11 away from the sample detection channel 1-10 and is connected to the waste liquid pool 1-11, and the waste liquid outlet 1-12 is a through hole; the first filter area 1-2, the inlet cone area 1-3, the pump cavity 1-4, the outlet cone area 1-6, the second filter area 1-7, the exhaust flow channel 1-9 and the bottom of the sample detection channel 1-10 are at the same height, and the bottom of the waste liquid pool 1-11 is lower than the bottom of the sample detection channel 1-10; a sloped inner wall 1-16 is provided between the outer frame 1-17 and the inner cavity 1-13;

[0009] The cylindrical copper substrate 2-2 in the piezoelectric ceramic buzzer 2 is bonded to the top of the inlet cone area 1-3, the pump cavity 1-4, and the outlet cone area 1-6 by an ultrasonic coupling agent to completely cover the three areas; the sealing cover plate 3 is buckled on the top of the piezoelectric ceramic buzzer 2 and the inner cavity 1-13, and the four side walls of the sealing cover plate 3 are tightly fitted with the inclined inner wall 1-16, and the bottom surface of the sealing cover plate 3 is tightly fitted with the inner cavity 1-13.

[0010] The working principle of the microfluidic biological sample detection chip with integrated pumping and micro-mixing functions of the present invention is as follows:

[0011] 1. Sample solution delivery:

[0012] When the microfluidic biomedical chip is working, the bottom of the solution inlet 1-1 is connected to the external sample solution, and then the piezoelectric ceramic buzzer piece 2 needs to be connected to the external device signal generator and power amplifier (the signal output end of the signal generator is connected to the signal input end of the power amplifier, and the signal output end of the power amplifier is connected to the signal input end of the piezoelectric ceramic buzzer piece 2). By setting different signal types and driving parameters output by the signal generator, the sample solution delivery flow rate can be controlled. Due to the inverse piezoelectric effect, the piezoelectric ceramic piece 2-1 in the piezoelectric ceramic buzzer piece 2 drives the copper substrate 2-2 to vibrate up and down after receiving the periodic electrical signal; when the piezoelectric ceramic buzzer piece 2 vibrates upward, the volume of the pump cavity 1-4 increases, and the pressure in the cavity decreases, and the sample solution is simultaneously sucked into the pump cavity 1-4 from both ends of the inlet cone tube area 1-3 and the outlet cone tube area 1-6 ( For the first time, only the inlet cone area 1-3 is sucked in), and this process is the suction stroke; when the piezoelectric ceramic buzzer 2 vibrates downward, the volume of the pump chamber 1-4 becomes smaller, and the pressure in the cavity increases, and the sample solution is discharged from the pump chamber 1-4 from both ends of the inlet cone area 1-3 and the outlet cone area 1-6 at the same time, and this process is the scheduling; although the sample solution enters and exits at the same time at both ends, the flow resistance coefficient in the direction in which the cross-sectional area of the conical flow channel gradually increases is smaller than the flow resistance coefficient in the opposite direction, so the net flow rate of the outlet cone area 1-6 is greater than zero, thereby realizing the one-way transportation of the sample solution from the solution inlet 1-1 to the sample detection channel 1-10; the cylindrical micro-column 1-14 is used to filter bubbles and large-sized blood cells in the sample solution; the exhaust hole 1-8 is connected to the sample detection channel 1-10 through the exhaust channel 1-9, so as to realize the discharge of air in the chip and the smooth flow of the sample solution;

[0013] 2. Microbubble vibration mixing:

[0014] There is cohesive force between liquid molecules. When there is a gas that is insoluble in the liquid, fewer liquid molecules adhere to the gas-liquid interface, thus forming a barrier, also known as a thin film. In order to form uniform microbubbles at a fixed position, an array of microporous structure blind holes 1-5 are designed at the bottom of the pump chamber 1-4. To ensure that no liquid enters the hydrophilic blind holes to capture bubbles, a hydrophobic coating is pre-coated in the blind holes. When the sample solution flows over the microporous structure blind holes 1-5, a gas-liquid interface can be formed with the help of liquid tension. When the flow rate range is certain, the microporous structure in the cavity can capture microbubbles, thereby forming a microbubble vibration mixing zone. The piezoelectric ceramic buzzer 2 controls the sample solution delivery flow rate and the microbubble vibration mixing time by changing the amplitude and frequency of the external input signal, thereby realizing the integration of pumping and micromixing.

[0015] When the piezoelectric ceramic buzzer 2 is working, it will generate a low-amplitude sound field. The microbubbles under the action of the sound field will exhibit radial vibrations symmetrical about their equilibrium radius, thereby forming a "fountain-like" microflow field in the sample solution. The turbulence generated by the microbubbles can achieve uniform mixing of the sample solution with the polystyrene fluorescent microspheres or magnetic beads pre-coated on the bottom of the pump chambers 1-4, realizing the simultaneous delivery of the sample solution and vibration mixing; the mixed sample solution is delivered to the sample detection channels 1-10 to complete the subsequent detection task; the role of the polystyrene fluorescent microspheres or magnetic beads is to combine with the antibody or antigen sample solution, and then emit light when illuminated by fluorescent light for detection;

[0016] 3. Waste liquid storage and drainage:

[0017] The waste liquid after passing through the sample detection channel 1-10 and completing the detection will flow into the waste liquid pool 1-11 for temporary storage. As the sample solution at the solution inlet 1-1 is continuously transported and detected, the excess waste liquid will flow out from the waste liquid outlet 1-12.

[0018] The present invention utilizes the amplitude and frequency of the input signal from a piezoelectric ceramic buzzer 2, in conjunction with the inlet and outlet conical sections 1-3 and 1-6 on either side of a pump chamber 1-4, to achieve unidirectional, quantitative delivery of a biological sample solution from a solution inlet 1-1 to a sample detection channel 1-10. Upon introduction of the sample solution into the array of blind holes 1-5 within the pump chamber 1-4, microbubbles of the same diameter as the blind holes are formed. Under the action of the piezoelectric ceramic buzzer 2, the microbubbles within the mixing zone vibrate at high frequencies, achieving efficient mixing of the sample solution with polystyrene fluorescent microspheres or magnetic beads pre-coated on the surface of the pump chamber 1-4.

[0019] The present invention proposes a microfluidic biological sample detection chip with integrated pumping and micro-mixing functions. It does not damage biomedical samples, can accurately and conveniently control the flow rate of sample reagents, and achieve efficient mixing and pumping of samples with fluorescent microspheres or magnetic beads, thereby realizing efficient detection of biological samples.

[0020] Different from the water-absorbing fibers and capillary drive methods of traditional antigen detection kits and chips, the present invention uses piezoelectric drive to achieve the functional integration of liquid pumping and micro-mixing, so that biological reagents can be quantitatively pumped from the inlet to the sample detection channel, while at the same time enabling the reagents to be fully mixed with fluorescent microspheres or magnetic beads, realizing efficient integration of structure and function. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 An exploded view of a microfluidic biological sample detection chip with integrated pumping and micro-mixing functions according to a first embodiment;

[0022] Figure 2 It is a top view of the chip body 1 of the first embodiment;

[0023] Figure 3 for Figure 2 A partial enlarged view of . DETAILED DESCRIPTION

[0024] Specific embodiment 1: This embodiment is a microfluidic biological sample detection chip with integrated pumping and micro-mixing functions, such as Figure 1-Figure 3 As shown, it is specifically composed of a chip body 1, a piezoelectric ceramic buzzer 2 and a sealing cover 3;

[0025] The piezoelectric ceramic buzzer 2 is composed of a cylindrical piezoelectric ceramic piece 2-1 at the upper end and a cylindrical copper substrate 2-2 at the lower end. The diameter of the cylindrical piezoelectric ceramic piece 2-1 is smaller than that of the cylindrical copper substrate 2-2. The centers of the cylindrical piezoelectric ceramic piece 2-1 and the cylindrical copper substrate 2-2 are on the same vertical line.

[0026] The upper surface of the sealing cover plate 3 is provided with a stepped through hole 3-1. The inner diameter of the upper end of the stepped through hole 3-1 is smaller. The stepped through hole 3-1 cooperates with the outer wall of the piezoelectric ceramic buzzer 2 for positioning. The sealing cover plate 3 is a quadrangular pyramid structure with a longer side length on the upper surface.

[0027] The chip body 1 is composed of an outer frame 1-17 and an inner cavity 1-13, the upper surface of the inner cavity 1-13 is lower than the upper surface of the outer frame 1-17; a circle of sealing strips 1-15 is provided near the edge of the upper surface of the inner cavity 1-13, and the sealing strips 1-15 are lower than the outer frame 1-17; the solution inlet 1-1, the first filter area 1-2, the inlet cone area 1-3, the pump cavity 1-4, the outlet cone area 1-6, the second filter area 1-7, the exhaust flow channel 1-9, the sample detection channel 1-10, the waste liquid pool 1-11 and the waste liquid outlet 1-12 are arranged in sequence in the inner cavity 1-13 in the sealing strip 1-15 and are all lower than the inner cavity 1-13; in the chip body 1 In the length direction, a sample solution inlet 1-1 is set near one end, and the solution inlet 1-1 is a through hole; the first filter area 1-2 is connected to the solution inlet 1-1, and a plurality of cylindrical micro-pillars 1-14 arranged in an array are vertically set in the first filter area 1-2, and the cylindrical micro-pillars 1-14 are at the same height as the inner cavity 1-13; the inlet cone tube area 1-3 is connected to the first filter area 1-2, and the vertical cross-sectional area of the inlet cone tube area 1-3 gradually decreases toward the direction of the first filter area 1-2, and the pump cavity 1-4 is connected to the end with the larger vertical cross-sectional area of the inlet cone tube area 1-3, and a plurality of blind holes 1-5 arranged in an array are set on the bottom surface of the pump cavity 1-4, and the inner wall of the blind hole 1-5 The top is coated with a hydrophobic coating, and the bottom surface of the pump chamber 1-4 is coated with polystyrene fluorescent microspheres or magnetic beads; the outlet cone pipe area 1-6 is connected to the pump chamber 1-4, and the vertical cross-sectional area of the outlet cone pipe area 1-6 gradually decreases toward the pump chamber 1-4; the second filter area 1-7 is connected to the end with the larger vertical cross-sectional area of the outlet cone pipe area 1-6, and a plurality of cylindrical micro-pillars 1-14 arranged in an array are vertically arranged in the second filter area 1-7, and the cylindrical micro-pillars 1-14 are at the same height as the inner cavity 1-13; the sample detection channel 1-10 is connected to the second filter area 1-7, and is connected to an exhaust flow channel 1-9 on both sides of the sample detection channel 1-10, and the exhaust flow channel 1-9 The end is an exhaust hole 1-8, and the exhaust hole 1-8 is a through hole; the waste liquid pool 1-11 is connected to the sample detection channel 1-10, and the waste liquid outlet 1-12 is arranged on the side of the waste liquid pool 1-11 away from the sample detection channel 1-10 and is connected to the waste liquid pool 1-11, and the waste liquid outlet 1-12 is a through hole; the first filter area 1-2, the inlet cone area 1-3, the pump cavity 1-4, the outlet cone area 1-6, the second filter area 1-7, the exhaust flow channel 1-9 and the bottom of the sample detection channel 1-10 are at the same height, and the bottom of the waste liquid pool 1-11 is lower than the bottom of the sample detection channel 1-10; a sloped inner wall 1-16 is provided between the outer frame 1-17 and the inner cavity 1-13;

[0028] The cylindrical copper substrate 2-2 in the piezoelectric ceramic buzzer 2 is bonded to the top of the inlet cone area 1-3, the pump cavity 1-4, and the outlet cone area 1-6 by an ultrasonic coupling agent to completely cover the three areas; the sealing cover 3 is buckled on the top of the piezoelectric ceramic buzzer 2 and the inner cavity 1-13, and the four side walls of the sealing cover 3 are tightly fitted with the inclined inner wall 1-16.

[0029] The working principle of the microfluidic biological sample detection chip with integrated pumping and micro-mixing functions in this embodiment is as follows:

[0030] 1. Sample solution delivery:

[0031] When the microfluidic biomedical chip is working, the bottom of the solution inlet 1-1 is connected to the external sample solution, and then the piezoelectric ceramic buzzer piece 2 needs to be connected to the external device signal generator and power amplifier (the signal output end of the signal generator is connected to the signal input end of the power amplifier, and the signal output end of the power amplifier is connected to the signal input end of the piezoelectric ceramic buzzer piece 2). By setting different signal types and driving parameters output by the signal generator, the sample solution delivery flow rate can be controlled. Due to the inverse piezoelectric effect, the piezoelectric ceramic piece 2-1 in the piezoelectric ceramic buzzer piece 2 drives the copper substrate 2-2 to vibrate up and down after receiving the periodic electrical signal; when the piezoelectric ceramic buzzer piece 2 vibrates upward, the volume of the pump cavity 1-4 increases, and the pressure in the cavity decreases, and the sample solution is simultaneously sucked into the pump cavity 1-4 from both ends of the inlet cone tube area 1-3 and the outlet cone tube area 1-6 ( For the first time, only the inlet cone area 1-3 is sucked in), and this process is the suction stroke; when the piezoelectric ceramic buzzer 2 vibrates downward, the volume of the pump chamber 1-4 becomes smaller, and the pressure in the cavity increases, and the sample solution is discharged from the pump chamber 1-4 from both ends of the inlet cone area 1-3 and the outlet cone area 1-6 at the same time, and this process is the scheduling; although the sample solution enters and exits at the same time at both ends, the flow resistance coefficient in the direction in which the cross-sectional area of the conical flow channel gradually increases is smaller than the flow resistance coefficient in the opposite direction, so the net flow rate of the outlet cone area 1-6 is greater than zero, thereby realizing the one-way transportation of the sample solution from the solution inlet 1-1 to the sample detection channel 1-10; the cylindrical micro-column 1-14 is used to filter bubbles and large-sized blood cells in the sample solution; the exhaust hole 1-8 is connected to the sample detection channel 1-10 through the exhaust channel 1-9, so as to realize the discharge of air in the chip and the smooth flow of the sample solution;

[0032] 2. Microbubble vibration mixing:

[0033] There is cohesive force between liquid molecules. When there is a gas that is insoluble in the liquid, fewer liquid molecules adhere to the gas-liquid interface, thus forming a barrier, also known as a thin film. In order to form uniform microbubbles at a fixed position, an array of microporous structure blind holes 1-5 are designed at the bottom of the pump chamber 1-4. To ensure that no liquid enters the hydrophilic blind holes to capture bubbles, a hydrophobic coating is pre-coated in the blind holes. When the sample solution flows over the microporous structure blind holes 1-5, a gas-liquid interface can be formed with the help of liquid tension. When the flow rate range is certain, the microporous structure in the cavity can capture microbubbles, thereby forming a microbubble vibration mixing zone. The piezoelectric ceramic buzzer 2 controls the sample solution delivery flow rate and the microbubble vibration mixing time by changing the amplitude and frequency of the external input signal, thereby realizing the integration of pumping and micromixing.

[0034] When the piezoelectric ceramic buzzer 2 is working, it will generate a low-amplitude sound field. The microbubbles under the action of the sound field will exhibit radial vibrations symmetrical about their equilibrium radius, thereby forming a "fountain-like" microflow field in the sample solution. The turbulence generated by the microbubbles can achieve uniform mixing of the sample solution with the polystyrene fluorescent microspheres or magnetic beads pre-coated on the bottom of the pump chambers 1-4, realizing the simultaneous delivery of the sample solution and vibration mixing; the mixed sample solution is delivered to the sample detection channels 1-10 to complete the subsequent detection task; the role of the polystyrene fluorescent microspheres or magnetic beads is to combine with the antibody or antigen sample solution, and then emit light when illuminated by fluorescent light for detection;

[0035] 3. Waste liquid storage and drainage:

[0036] The waste liquid after passing through the sample detection channel 1-10 and completing the detection will flow into the waste liquid pool 1-11 for temporary storage. As the sample solution at the solution inlet 1-1 is continuously transported and detected, the excess waste liquid will flow out from the waste liquid outlet 1-12.

[0037] This embodiment achieves unidirectional, quantitative delivery of a biological sample solution from the solution inlet 1-1 to the sample detection channel 1-10 by combining the amplitude and frequency of the input signal from the piezoelectric ceramic buzzer 2 with the inlet and outlet conical sections 1-3 and 1-6 on either side of the pump chamber 1-4. Upon introduction of the sample solution into the array of blind holes 1-5 within the pump chamber 1-4, microbubbles of the same diameter are formed. Driven by the piezoelectric ceramic buzzer 2, the microbubbles within the mixing zone oscillate at high frequencies, achieving efficient mixing of the sample solution with the polystyrene fluorescent microspheres or magnetic beads pre-coated on the surface of the pump chamber 1-4.

[0038] This embodiment proposes a microfluidic biological sample detection chip with integrated pumping and micro-mixing functions, which does not cause damage to biomedical samples, can accurately and conveniently control the flow rate of sample reagents, achieve efficient mixing and pumping of samples and fluorescent microspheres or magnetic beads, and thus realize efficient detection of biological samples.

[0039] Different from the water-absorbing fibers and capillary drive methods of traditional antigen detection kits and chips, this embodiment uses piezoelectric drive to achieve the functional integration of liquid pumping and micro-mixing, so that biological reagents can be quantitatively pumped from the inlet to the sample detection channel, while at the same time enabling the reagents to be fully mixed with fluorescent microspheres or magnetic beads, realizing efficient integration of structure and function.

[0040] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the volume of the waste liquid pool 1-11 is 100 μL to 150 μL. Other aspects are the same as specific embodiment 1.

[0041] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that the height of the sealing strip 1-15 is 0.1mm-0.5mm and the material is rubber. Other aspects are the same as specific embodiment 1 or 2.

[0042] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the shape of the pump chambers 1-4 is circular or square. Other aspects are the same as specific embodiments 1 to 3.

[0043] Specific embodiment 5: This embodiment differs from specific embodiment 4 in that the taper angle of the inlet cone section 1-3 is less than 35°. Other aspects are the same as specific embodiment 4.

[0044] Specific embodiment 6: This embodiment differs from specific embodiment 5 in that the taper angle of the outlet cone section 1-6 is less than 35°. Other aspects are the same as specific embodiment 5.

[0045] Specific embodiment 7: This embodiment differs from specific embodiment 6 in that the diameter of the blind holes 1-5 is 0.3mm to 0.8mm, and the center distance between adjacent blind holes 1-5 is 2 to 3 times the diameter of the blind holes 1-5. Other aspects are the same as specific embodiment 6.

[0046] Specific embodiment eight: This embodiment differs from specific embodiment seven in that the piezoelectric ceramic sheet 2-1 is made of barium titanate, lead zirconate titanate, or lead magnesium niobate; and the copper substrate 2-2 is made of brass. Other aspects are the same as specific embodiment seven.

[0047] Specific embodiment 9: This embodiment differs from specific embodiment 8 in that the chip body 1 and the sealing cover plate 3 are both made of PMMA, and are manufactured by programming a precision engraving machine and then bonded with UV glue. Other aspects are the same as specific embodiment 8.

[0048] Specific embodiment 10: This embodiment differs from specific embodiment 9 in that the chip body 1 and sealing cover plate 3 are both made of the same material, PDMS or silicone. They are processed using soft etching technology and molds, and then bonded after being treated in a plasma cleaner. Other aspects are the same as specific embodiment 9.

[0049] The present invention is verified by the following test:

[0050] Experiment 1: This experiment is a microfluidic biological sample detection chip with integrated pumping and micro-mixing functions, such as Figure 1-Figure 3 As shown, it is specifically composed of a chip body 1, a piezoelectric ceramic buzzer 2 and a sealing cover 3;

[0051] The piezoelectric ceramic buzzer 2 is composed of a cylindrical piezoelectric ceramic piece 2-1 at the upper end and a cylindrical copper substrate 2-2 at the lower end. The diameter of the cylindrical piezoelectric ceramic piece 2-1 is smaller than that of the cylindrical copper substrate 2-2. The centers of the cylindrical piezoelectric ceramic piece 2-1 and the cylindrical copper substrate 2-2 are on the same vertical line. The outer diameter of the cylindrical copper substrate 2-2 is 12 mm.

[0052] The upper surface of the sealing cover plate 3 is provided with a stepped through hole 3-1. The inner diameter of the upper end of the stepped through hole 3-1 is smaller. The stepped through hole 3-1 cooperates with the outer wall of the piezoelectric ceramic buzzer 2 for positioning. The sealing cover plate 3 is a quadrangular pyramid structure with a longer side length on the upper surface.

[0053] The chip body 1 is composed of an outer frame 1-17 and an inner cavity 1-13, the upper surface of the inner cavity 1-13 is lower than the upper surface of the outer frame 1-17; a circle of sealing strips 1-15 is provided near the edge of the upper surface of the inner cavity 1-13, and the sealing strips 1-15 are lower than the outer frame 1-17; the solution inlet 1-1, the first filter area 1-2, the inlet cone area 1-3, the pump cavity 1-4, the outlet cone area 1-6, the second filter area 1-7, the exhaust flow channel 1-9, the sample detection channel 1-10, the waste liquid pool 1-11 and the waste liquid outlet 1-12 are arranged in sequence in the inner cavity 1-13 in the sealing strip 1-15 and are all lower than the inner cavity 1-13; in the chip body 1 In the length direction, a sample solution inlet 1-1 is set near one end, and the solution inlet 1-1 is a through hole; the first filter area 1-2 is connected to the solution inlet 1-1, and a plurality of cylindrical micro-pillars 1-14 arranged in an array are vertically set in the first filter area 1-2, and the cylindrical micro-pillars 1-14 are at the same height as the inner cavity 1-13; the inlet cone tube area 1-3 is connected to the first filter area 1-2, and the vertical cross-sectional area of the inlet cone tube area 1-3 gradually decreases toward the direction of the first filter area 1-2, and the pump cavity 1-4 is connected to the end with the larger vertical cross-sectional area of the inlet cone tube area 1-3, and a plurality of blind holes 1-5 arranged in an array are set on the bottom surface of the pump cavity 1-4, and the inner wall of the blind hole 1-5 The top is coated with a hydrophobic coating, and the bottom surface of the pump chamber 1-4 is coated with polystyrene fluorescent microspheres or magnetic beads; the outlet cone pipe area 1-6 is connected to the pump chamber 1-4, and the vertical cross-sectional area of the outlet cone pipe area 1-6 gradually decreases toward the pump chamber 1-4; the second filter area 1-7 is connected to the end with the larger vertical cross-sectional area of the outlet cone pipe area 1-6, and a plurality of cylindrical micro-pillars 1-14 arranged in an array are vertically arranged in the second filter area 1-7, and the cylindrical micro-pillars 1-14 are at the same height as the inner cavity 1-13; the sample detection channel 1-10 is connected to the second filter area 1-7, and is connected to an exhaust flow channel 1-9 on both sides of the sample detection channel 1-10, and the exhaust flow channel 1-9 The end is an exhaust hole 1-8, and the exhaust hole 1-8 is a through hole; the waste liquid pool 1-11 is connected to the sample detection channel 1-10, and the waste liquid outlet 1-12 is arranged on the side of the waste liquid pool 1-11 away from the sample detection channel 1-10 and is connected to the waste liquid pool 1-11, and the waste liquid outlet 1-12 is a through hole; the first filter area 1-2, the inlet cone area 1-3, the pump cavity 1-4, the outlet cone area 1-6, the second filter area 1-7, the exhaust flow channel 1-9 and the bottom of the sample detection channel 1-10 are at the same height, and the bottom of the waste liquid pool 1-11 is lower than the bottom of the sample detection channel 1-10; a sloped inner wall 1-16 is provided between the outer frame 1-17 and the inner cavity 1-13;

[0054] The volume of the waste liquid pool 1-11 is 132 μL;

[0055] The sealing strip 1-15 has a height of 0.1 mm and is made of rubber;

[0056] The pump chambers 1-4 are circular in shape with an inner diameter of 7 mm;

[0057] The taper of the inlet cone section 1-3 is 10°; the taper of the outlet cone section 1-6 is 10°;

[0058] The diameter of the blind holes 1-5 is 0.3 mm, the center distance between adjacent blind holes 1-5 is twice the diameter of the blind holes 1-5, and the number of blind holes 1-5 is 49;

[0059] The material of the piezoelectric ceramic sheet 2-1 is lead zirconate titanate; the material of the copper substrate 2-2 is brass;

[0060] The chip body 1 and the sealing cover plate 3 are both made of PMMA, and are processed by a precision engraving machine and then bonded with UV glue.

[0061] The cylindrical copper substrate 2-2 in the piezoelectric ceramic buzzer 2 is bonded to the top of the inlet cone area 1-3, the pump cavity 1-4, and the outlet cone area 1-6 by an ultrasonic coupling agent to completely cover the three areas; the sealing cover 3 is buckled on the top of the piezoelectric ceramic buzzer 2 and the inner cavity 1-13, and the four side walls of the sealing cover 3 are tightly fitted with the inclined inner wall 1-16.

[0062] The working principle of the microfluidic biological sample detection chip with integrated pumping and micro-mixing functions in this experiment is as follows:

[0063] 1. Sample solution delivery:

[0064] When the microfluidic biomedical chip is working, the bottom of the solution inlet 1-1 is connected to the external sample solution, and then the piezoelectric ceramic buzzer piece 2 needs to be connected to the external device signal generator and power amplifier (the signal output end of the signal generator is connected to the signal input end of the power amplifier, and the signal output end of the power amplifier is connected to the signal input end of the piezoelectric ceramic buzzer piece 2). By setting different signal types and driving parameters output by the signal generator, the sample solution delivery flow rate can be controlled. Due to the inverse piezoelectric effect, the piezoelectric ceramic piece 2-1 in the piezoelectric ceramic buzzer piece 2 drives the copper substrate 2-2 to vibrate up and down after receiving the periodic electrical signal; the signal type of this experiment is set to a sine wave, with a peak-to-peak voltage of 50V and a frequency of 80Hz; when the piezoelectric ceramic buzzer piece 2 vibrates upward, the volume of the pump chamber 1-4 increases, and the pressure in the cavity decreases, and the sample solution is pumped from the inlet cone tube area 1-3 and the outlet cone tube area 1 -6 are simultaneously sucked into the pump chamber 1-4 at both ends (only sucked from the inlet cone area 1-3 for the first time), and this process is the suction stroke; when the piezoelectric ceramic buzzer 2 vibrates downward, the volume of the pump chamber 1-4 becomes smaller, and the pressure in the cavity increases, and the sample solution is discharged from the pump chamber 1-4 from both ends of the inlet cone area 1-3 and the outlet cone area 1-6 at the same time, and this process is the scheduling; although the sample solution enters and exits at the same time at both ends, the flow resistance coefficient in the direction in which the cross-sectional area of the conical flow channel gradually increases is smaller than the flow resistance coefficient in the opposite direction, so the net flow rate of the outlet cone area 1-6 is greater than zero, thereby realizing the one-way transportation of the sample solution from the solution inlet 1-1 to the sample detection channel 1-10; the cylindrical micro-column 1-14 is used to filter bubbles and large-sized blood cells in the sample solution; the exhaust hole 1-8 is connected to the sample detection channel 1-10 through the exhaust channel 1-9, so as to realize the discharge of air in the chip and the smooth flow of the sample solution;

[0065] 2. Microbubble vibration mixing:

[0066] There is cohesive force between liquid molecules. When there is a gas that is insoluble in the liquid, fewer liquid molecules adhere to the gas-liquid interface, thus forming a barrier, also known as a thin film. In order to form uniform microbubbles at a fixed position, an array of microporous structure blind holes 1-5 are designed at the bottom of the pump chamber 1-4. To ensure that no liquid enters the hydrophilic blind holes to capture bubbles, a hydrophobic coating is pre-coated in the blind holes. When the sample solution flows over the microporous structure blind holes 1-5, a gas-liquid interface can be formed with the help of liquid tension. When the flow rate range is certain, the microporous structure in the cavity can capture microbubbles, thereby forming a microbubble vibration mixing zone. The piezoelectric ceramic buzzer 2 controls the sample solution delivery flow rate and the microbubble vibration mixing time by changing the amplitude and frequency of the external input signal, thereby realizing the integration of pumping and micromixing.

[0067] When the piezoelectric ceramic buzzer 2 is working, it will generate a low-amplitude sound field. The microbubbles under the action of the sound field will exhibit radial vibrations symmetrical about their equilibrium radius, thereby forming a "fountain-like" microflow field in the sample solution. The turbulence generated by the microbubbles can achieve uniform mixing of the sample solution with the polystyrene fluorescent microspheres or magnetic beads pre-coated on the bottom of the pump chambers 1-4, realizing the simultaneous delivery of the sample solution and vibration mixing; the mixed sample solution is delivered to the sample detection channels 1-10 to complete the subsequent detection task; the role of the polystyrene fluorescent microspheres or magnetic beads is to combine with the antibody or antigen sample solution, and then emit light when illuminated by fluorescent light for detection;

[0068] 3. Waste liquid storage and drainage:

[0069] The waste liquid after passing through the sample detection channel 1-10 and completing the detection will flow into the waste liquid pool 1-11 for temporary storage. As the sample solution at the solution inlet 1-1 is continuously transported and detected, the excess waste liquid will flow out from the waste liquid outlet 1-12.

[0070] This experiment achieves unidirectional, quantitative delivery of a biological sample solution from solution inlet 1-1 to sample detection channel 1-10 by combining the amplitude and frequency of the input signal from piezoelectric ceramic buzzer 2 with the inlet and outlet conical sections 1-3 and 1-6 on either side of pump chamber 1-4. Microbubbles of the same diameter as the blind holes 1-5 arranged in an array within pump chamber 1-4 are formed upon introduction of the sample solution. Driven by the piezoelectric ceramic buzzer 2, the microbubbles within the mixing zone oscillate at high frequencies, achieving efficient mixing of the sample solution with polystyrene fluorescent microspheres or magnetic beads pre-coated on the surface of pump chamber 1-4.

[0071] This experiment proposes a microfluidic biological sample detection chip with integrated pumping and micro-mixing functions. It does not cause damage to biomedical samples, can accurately and conveniently control the flow rate of sample reagents, and achieve efficient mixing and pumping of samples and fluorescent microspheres or magnetic beads, thereby realizing efficient detection of biological samples.

[0072] Different from the water-absorbing fiber and capillary drive methods of traditional antigen detection kits and chips, this experiment uses piezoelectric drive to achieve the functional integration of liquid pumping and micro-mixing, so that biological reagents can be quantitatively pumped from the inlet to the sample detection channel, while at the same time enabling the reagents to be fully mixed with fluorescent microspheres or magnetic beads, realizing efficient integration of structure and function.

Claims

1. A microfluidic biological sample detection chip with integrated pumping and micro-mixing functions, characterized in that A microfluidic biological sample detection chip with integrated pumping and micro-mixing functions is composed of a chip body (1), a piezoelectric ceramic buzzer (2) and a sealing cover (3); The piezoelectric ceramic buzzer (2) is composed of a cylindrical piezoelectric ceramic piece (2-1) at the upper end and a cylindrical copper base plate (2-2) at the lower end. The diameter of the cylindrical piezoelectric ceramic piece (2-1) is smaller than that of the cylindrical copper base plate (2-2). The centers of the cylindrical piezoelectric ceramic piece (2-1) and the cylindrical copper base plate (2-2) are on the same vertical line. A stepped through hole (3-1) is provided on the upper surface of the sealing cover plate (3); the inner diameter of the upper end of the stepped through hole (3-1) is relatively small; the stepped through hole (3-1) and the outer wall of the piezoelectric ceramic buzzer (2) cooperate with each other for positioning; the sealing cover plate (3) is a quadrangular pyramid structure, and the side length of the upper surface is relatively long; The chip body (1) is composed of an outer frame (1-17) and an inner cavity (1-13), wherein the upper surface of the inner cavity (1-13) is lower than the upper surface of the outer frame (1-17); a circle of sealing strips (1-15) is provided near the edge of the upper surface of the inner cavity (1-13), and the sealing strips (1-15) are lower than the outer frame (1-17); the solution inlet (1-1), the first filter area (1-2), the inlet cone area (1-3), the pump cavity (1-4), the outlet cone area (1-6), the second filter area (1-7), the exhaust flow channel (1-9), the sample detection channel (1-10), the waste liquid pool (1-11) and the waste liquid outlet (1-12) are sequentially arranged in the inner cavity (1-13) within the sealing strip (1-15) and are all lower than the inner cavity. (1-13) is low; in the longitudinal direction of the chip body (1), a sample solution inlet (1-1) is provided near one end, and the solution inlet (1-1) is a through hole; the first filter area (1-2) is connected to the solution inlet (1-1), and a plurality of cylindrical micro-pillars (1-14) arranged in an array are vertically provided in the first filter area (1-2), and the cylindrical micro-pillars (1-14) are at the same height as the inner cavity (1-13); the inlet cone area (1-3) is connected to the first filter area (1-2), and the vertical cross-sectional area of the inlet cone area (1-3) gradually decreases toward the direction of the first filter area (1-2); the pump cavity (1-4) is connected to the end of the inlet cone area (1-3) with the larger vertical cross-sectional area, and a plurality of array-arranged micro-pillars (1-14) are provided on the bottom surface of the pump cavity (1-4). The blind hole (1-5) is provided with a hydrophobic coating on the inner wall of the blind hole (1-5), and the bottom surface of the pump cavity (1-4) is coated with polystyrene fluorescent microspheres or magnetic beads; the outlet cone tube area (1-6) is connected to the pump cavity (1-4), and the vertical cross-sectional area of the outlet cone tube area (1-6) gradually decreases toward the pump cavity (1-4); the second filter area (1-7) is connected to the end of the outlet cone tube area (1-6) with the larger vertical cross-sectional area, and a plurality of cylindrical micro-pillars (1-14) arranged in an array are vertically arranged in the second filter area (1-7), and the cylindrical micro-pillars (1-14) are at the same height as the inner cavity (1-13); the sample detection channel (1-10) is connected to the second filter area (1-7), and is connected to a filter on both sides of the sample detection channel (1-10). The exhaust flow channel (1-9) is connected, the end of the exhaust flow channel (1-9) is an exhaust hole (1-8), and the exhaust hole (1-8) is a through hole; the waste liquid pool (1-11) is connected to the sample detection channel (1-10), the waste liquid outlet (1-12) is arranged on a side of the waste liquid pool (1-11) away from the sample detection channel (1-10) and is connected to the waste liquid pool (1-11), and the waste liquid outlet (1-12) is a through hole; the bottoms of the first filter area (1-2), the inlet cone area (1-3), the pump chamber (1-4), the outlet cone area (1-6), the second filter area (1-7), the exhaust flow channel (1-9) and the sample detection channel (1-10) are at the same height, and the bottom of the waste liquid pool (1-11) is lower than the bottom of the sample detection channel (1-10);An inclined inner wall (1-16) is provided between the outer frame (1-17) and the inner cavity (1-13); The cylindrical copper substrate (2-2) in the piezoelectric ceramic buzzer (2) is bonded to the upper part of the inlet cone tube area (1-3), the pump cavity (1-4), and the outlet cone tube area (1-6) by an ultrasonic coupling agent to completely cover the three areas; the sealing cover (3) is buckled on the upper part of the piezoelectric ceramic buzzer (2) and the inner cavity (1-13), and the four side walls of the sealing cover (3) are tightly fitted with the inclined inner wall (1-16).

2. A microfluidic biological sample detection chip with integrated pumping and micro-mixing functions according to claim 1, characterized in that The volume of the waste liquid pool (1-11) is 100 μL to 150 μL.

3. The microfluidic biological sample detection chip with integrated pumping and micro-mixing functions according to claim 1, characterized in that The sealing strip (1-15) has a height of 0.1mm to 0.5mm and is made of rubber.

4. The microfluidic biological sample detection chip with integrated pumping and micro-mixing functions according to claim 1, characterized in that The shape of the pump chamber (1-4) is circular or square.

5. The microfluidic biological sample detection chip with integrated pumping and micro-mixing functions according to claim 1, characterized in that The taper of the inlet cone pipe area (1-3) is less than 35 degrees.

6. The microfluidic biological sample detection chip integrating pumping and micro-mixing functions according to claim 1, characterized in that The taper of the outlet cone pipe area (1-6) is less than 35 degrees.

7. The microfluidic biological sample detection chip integrating pumping and micro-mixing functions according to claim 1, characterized in that The diameter of the blind hole (1-5) is 0.3mm to 0.8mm, and the center distance between adjacent blind holes (1-5) is 2 to 3 times the diameter of the blind hole (1-5).

8. The microfluidic biological sample detection chip with integrated pumping and micro-mixing functions according to claim 1, characterized in that The material of the piezoelectric ceramic sheet (2-1) is barium titanate, lead zirconate titanate or lead magnesium niobate; the material of the copper substrate (2-2) is brass.

9. The microfluidic biological sample detection chip integrating pumping and micro-mixing functions according to claim 1, characterized in that The chip body (1) and the sealing cover plate (3) are both made of PMMA, and are manufactured by programming a precision engraving machine and then bonded together by UV glue.

10. The microfluidic biological sample detection chip integrating pumping and micro-mixing functions according to claim 1, characterized in that The chip body (1) and the sealing cover plate (3) are both made of PDMS or silica gel, which are the same material. The two are processed by soft etching technology and molds, and then bonded after being processed by a plasma cleaning machine.

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