Piezoelectric ultrasonic self-cleaning micro-fluidic chip

Abstract

The invention discloses a piezoelectric ultrasonic self-cleaning micro-fluidic chip, and belongs to the technical field of micro-fluidic. The device comprises a piezoelectric ultrasonic wave generating device, a micro-fluidic chip and a cleaning solution, the micro-fluidic chip is fixedly arranged on the piezoelectric ultrasonic wave generating device, a micro-channel is arranged in the micro-fluidic chip, or a micro-structure arranged at the bottom of the micro-fluidic chip and the piezoelectric ultrasonic wave generating device are irreversibly sealed to form the micro-channel; the upper surface of the micro-fluidic chip is provided with at least one liquid inlet and a liquid outlet which are communicated with the micro-channel, and the cleaning liquid enters the micro-channel through the liquid inlet, flows along the micro-channel and is discharged through the liquid outlet. High-frequency ultrasonic surface waves are generated through the piezoelectric ultrasonic wave generating device and enter the micro-channel of the micro-fluidic chip in a coupling mode, the acoustic streaming effect is formed in the cleaning liquid, retentates in the micro-fluidic chip, especially in a corner area, can be effectively removed, and the cleaning efficiency and controllability of the micro-fluidic chip are improved.

Description

Technical Field

[0001] This invention belongs to the field of microfluidics technology, specifically relating to a piezoelectric ultrasonic self-cleaning microfluidic chip. Background Art

[0002] Microfluidic chips, based on the manipulation of micro-volume liquids at the microscale (typically <1 mm), are widely used in biochemical analysis, medical diagnostics, food testing, and aerospace, offering advantages such as small size, low power consumption, high throughput, and high integration. Most microfluidic chips incorporate corner structures to change the flow direction of the transport medium; however, fluid flow in these corner regions is complex, often accompanied by strong secondary flows, which can easily lead to channel blockage and affect chip performance. Therefore, improving the chip's self-cleaning capability and enhancing the reliability of microfluidic transport remain crucial issues in microfluidic technology.

[0003] Currently, the main cleaning methods are positive pressure cleaning fluid cleaning and negative pressure suction. These methods are prone to causing microfluidic chip seal breakage and reagent contamination. Some studies have also tried to reduce liquid retention at corners by improving the corner geometry (such as specially designed arc structures). However, such microfluidic chips are difficult to process in practice, and these traditional cleaning processes have poor controllability and poor cleaning effect. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of current microfluidic chips being prone to clogging, chip breakage caused by traditional cleaning methods, poor controllability of the cleaning process and poor cleaning effect, and difficulty in processing and manufacturing due to changes in corner geometry to reduce liquid retention at corners. The invention provides a piezoelectric ultrasonic self-cleaning microfluidic chip.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A piezoelectric ultrasonic self-cleaning microfluidic chip includes a piezoelectric ultrasonic generator, a microfluidic chip, and a cleaning fluid. The microfluidic chip is fixedly mounted on the piezoelectric ultrasonic generator. The microfluidic chip has a microchannel inside, or a microstructure on the bottom of the microfluidic chip is irreversibly sealed with the piezoelectric ultrasonic generator to form a closed microchannel. The upper surface of the microfluidic chip has at least one liquid inlet and one liquid outlet communicating with the microchannel. The cleaning fluid enters the microchannel through the liquid inlet, flows along the microchannel, and is discharged through the liquid outlet.

[0007] Furthermore, the piezoelectric ultrasonic generator includes a piezoelectric substrate, electrodes, an acoustic absorption block, and an AC excitation module; the electrodes are located at one end of the upper surface of the piezoelectric substrate and are integrally formed, and the acoustic absorption block is fixed on the upper surface of the piezoelectric substrate; the AC excitation module is connected to the positive and negative terminals of the electrodes via leads; the microfluidic chip is fixed on the upper surface of the piezoelectric substrate, and the microstructure at the bottom of the microfluidic chip forms a closed microchannel with the upper surface of the piezoelectric substrate through irreversible sealing.

[0008] Furthermore, the piezoelectric ultrasonic generator includes a piezoelectric ceramic sheet, a brass substrate, a sound absorption block, and an AC excitation module; the piezoelectric ceramic sheet and the sound absorption block are both fixed on the upper surface of the brass substrate, and the AC excitation module is connected to the piezoelectric ceramic sheet and the brass substrate respectively through the positive and negative poles of the excitation signal leads; the microfluidic chip is fixed on the upper surface of the brass substrate, and the microstructure provided at the bottom of the microfluidic chip forms a closed microchannel with the upper surface of the brass substrate through irreversible sealing.

[0009] Furthermore, the electrode is formed at one end of the upper surface of the piezoelectric substrate by magnetron sputtering and ion beam etching processes.

[0010] Furthermore, the piezoelectric substrate is lithium niobate, piezoelectric ceramic, or piezoelectric polymer material with a Y-128° tangential orientation, or a composite substrate composed of a glass, metal, or plastic non-piezoelectric material and a piezoelectric thin film with a thickness of 0.2 mm to 1 mm deposited on its surface.

[0011] Furthermore, the electrode is a rectangular interdigitated electrode or an arc-shaped interdigitated electrode, and the electrode material is one or a combination of several of the following: gold, platinum, aluminum, silver, FTO conductive glass, titanium, chromium, and carbon.

[0012] Furthermore, the shape of the microchannel is one or a combination of straight lines, broken lines, and arcs; the overall depth of the microchannel remains consistent, and the overall width of the microchannel may be the same or different.

[0013] Furthermore, at least two microchannels are arranged side-by-side along the length or width direction of the microfluidic chip.

[0014] Furthermore, the cleaning solution is a solution of deionized water, methanol, ethanol, isopropanol, or acetone.

[0015] Furthermore, the material of the sound-absorbing block is rubber, sound-absorbing foam, or glass fiber.

[0016] The advantages of this invention compared to existing technologies are as follows: The piezoelectric ultrasonic self-cleaning microfluidic chip provided by this invention generates ultrasonic surface waves on the substrate surface through an AC excitation module, achieving the self-cleaning function of the microfluidic chip. The piezoelectric ultrasonic generator does not require mechanical drive, has a simple structure, small size, high acoustic-to-electric conversion efficiency, low power consumption, and is easy to integrate with other systems; the piezoelectric ultrasonic waves can be rapidly adjusted by changing the amplitude and frequency of the excitation signal, resulting in higher controllability and faster response speed; the acoustic flow effect generated inside the cleaning fluid forms an acoustic vortex, removing residues inside the microchannel, especially in the corner areas, resulting in higher cleaning efficiency without damaging the microfluidic chip; the cleaning fluid can be deionized water or other liquids (methanol, ethanol, isopropanol, or acetone solution), which is less likely to cause reagent contamination and affect use; this cleaning method does not require special design of the microchannel structure, resulting in low manufacturing cost of the microfluidic chip. Attached Figure Description

[0017] Figure 1 This is the front view of the piezoelectric ultrasonic self-cleaning microfluidic chip of the present invention. Figure 1 The microchannels are located inside the microfluidic chip;

[0018] Figure 2 Top view of the piezoelectric ultrasonic self-cleaning microfluidic chip of the present invention. Figure 1 ;

[0019] Figure 3 This is a top view of the arc-shaped interdigitated electrode structure 1;

[0020] Figure 4 This is a top view of the second arc-shaped interdigitated electrode structure;

[0021] Figure 5 This is a top view of a piezoelectric ceramic transducer;

[0022] Figure 6 This is the front view of the piezoelectric ultrasonic self-cleaning microfluidic chip of the present invention. Figure 2 The main view of the microstructure at the bottom of the microfluidic chip forming a closed microchannel with the upper surface of the piezoelectric substrate through irreversible sealing;

[0023] Figure 7 A top view of a Y-shaped microchannel;

[0024] Figure 8 This is a top view of a polygonal microchannel.

[0025] Figure 9 This is a top view of a microchannel composed of a combination of 'T'-shaped and annular microchannels.

[0026] Figure 10 A top view of a microfluidic chip;

[0027] Figure 11 This is the front view of the piezoelectric ultrasonic self-cleaning microfluidic chip of the present invention. Figure 3 The microchannels are located inside the microfluidic chip;

[0028] Figure 12 Top view of the piezoelectric ultrasonic self-cleaning microfluidic chip of the present invention. Figure 3 ;

[0029] Figure 13 This is the front view of the piezoelectric ultrasonic self-cleaning microfluidic chip of the present invention. Figure 4 The microstructure at the bottom of the microfluidic chip forms a closed microchannel with the upper surface of the brass substrate through an irreversible seal;

[0030] The component names and reference numerals in the above figures are as follows:

[0031] 1. Piezoelectric substrate, 2. Electrode, 3. Microfluidic chip, 3-1 liquid inlet, 3-2 microchannel, 3-3 liquid outlet, 4. Cleaning fluid, 5. Sound absorption block, 6. AC excitation module, 7. Piezoelectric ceramic, 8. Brass substrate. DETAILED DESCRIPTION

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The described embodiments are only a part of the embodiments of the present invention and are not limited thereto. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Specific implementation method one: as follows Figures 1-4 , Figure 6 As shown, this embodiment discloses a piezoelectric ultrasonic self-cleaning microfluidic chip, including a piezoelectric ultrasonic generator, a microfluidic chip 3, and a cleaning fluid 4. The microfluidic chip 3 is fixedly mounted on the piezoelectric ultrasonic generator. A microchannel 3-2 is provided inside the microfluidic chip 3, or the microstructure at the bottom of the microfluidic chip 3 is irreversibly sealed with the piezoelectric ultrasonic generator to form a closed microchannel 3-2, achieving bonding of the contact surfaces and ensuring that the cleaning fluid 4 inside the microfluidic chip 3 does not leak. At least one liquid inlet 3-1 and liquid outlet 3-3 communicating with the microchannel 3-2 are vertically opened on the upper surface of the microfluidic chip 3 (the liquid inlet 3-1 and liquid outlet 3-3 are formed by drilling holes at both ends of the microchannel 3-2 using a chip punch). The cleaning fluid 4 enters the microchannel 3-2 through the liquid inlet 3-1, flows along the microchannel 3-2, and is discharged through the liquid outlet 3-3 under the action of acoustic pressure. The electrode 2 is a rectangular interdigitated electrode or an arc-shaped interdigitated electrode (which is the prior art).

[0034] The piezoelectric ultrasonic generator includes a piezoelectric substrate 1, an electrode 2, a sound-absorbing block 5, and an AC excitation module 6. The electrode 2 is located at one end of the upper surface of the piezoelectric substrate 1 and the two are integrally formed. The sound-absorbing block 5 is fixed to the upper surface of the piezoelectric substrate 1 (the sound-absorbing block 5 is fixed to the upper surface of the piezoelectric substrate 1 by epoxy resin adhesive, and preferably there are two sound-absorbing blocks 5, which are set at both ends of the upper surface of the piezoelectric substrate 1 to absorb ultrasonic waves). The AC excitation module 6 is connected to the positive and negative poles of the electrode 2 through leads to provide excitation signals to the piezoelectric ultrasonic generator. The microfluidic chip 3 is fixed to the upper surface of the piezoelectric substrate 1, and the microstructure at the bottom of the microfluidic chip 3 is irreversibly sealed with the upper surface of the piezoelectric substrate 1 to form a closed microchannel 3-2.

[0035] like Figure 1 As shown, a microchannel 3-2 is set inside the microfluidic chip 3, and the cleaning fluid 4 does not directly contact the piezoelectric substrate 1 when it flows through the microchannel 3-2.

[0036] like Figure 6 As shown, a microstructure is set at the bottom of the microfluidic chip 3. The microstructure and the upper surface of the piezoelectric substrate 1 are irreversibly sealed to form a closed microchannel 3-2. The cleaning liquid 4 in the microchannel 3-2 is in direct contact with the piezoelectric substrate 1.

[0037] like Figure 2 As shown, the electrode 2 is formed at one end of the upper surface of the piezoelectric substrate 1 by magnetron sputtering and ion beam etching.

[0038] The piezoelectric substrate 1 is lithium niobate (LiNbO3) with a Y-128° tangent, a piezoelectric ceramic or a piezoelectric polymer material, or a composite substrate consisting of a glass, metal or plastic non-piezoelectric material and a piezoelectric thin film with a thickness of 0.2 mm to 1 mm deposited on its surface.

[0039] like Figure 2 As shown; the width of the interdigitated fingers of the rectangular interdigitated electrode is 3μm to 10μm, the gap between two adjacent interdigitated fingers is 5μm to 15μm, the thickness of the interdigitated fingers is 0.01μm to 0.05μm, and the number of interdigitated finger pairs is 30 to 90 pairs; the material of the electrode 2 is one or a combination of several of gold, platinum, aluminum, silver, FTO conductive glass, titanium, chromium, and carbon.

[0040] The microfluidic chip 3 is made of one or a combination of several of the following materials: polydimethylsiloxane, polymethyl methacrylate, glass, and polymer resin.

[0041] like Figures 7-9As shown, the shape of the microchannel 3-2 is one or a combination of straight line, broken line, and arc shape, such as a 'Y' shaped microchannel (a combination of broken line and straight line microchannels), a broken line microchannel, an arc microchannel, a 'T' shaped microchannel, and a ring microchannel (a combination of straight line and arc microchannels). Figure 10 The diagram shows four types of microchannels integrated on the same microfluidic chip 3. These four types of microchannels are: 'Y'-shaped microchannel, arc-shaped microchannel, zigzag-shaped microchannel, and a combination of straight and arc-shaped microchannels.

[0042] The overall depth of microchannel 3-2 remains consistent; the width of microchannel 3-2 is 0.1mm to 1mm, the depth of microchannel 3-2 is 0.1mm to 0.5mm, and the overall width of microchannel 3-2 may be the same or different.

[0043] At least two microchannels 3-2 are arranged side by side along the length or width of the microfluidic chip 3.

[0044] The cleaning solution 4 is a solution of deionized water, methanol, ethanol, isopropanol, or acetone.

[0045] like Figure 1 , Figure 2 As shown, the sound-absorbing block 5 is made of rubber, sound-absorbing foam, or glass fiber. This allows ultrasonic waves to enter the sound-absorbing material without reflection and for most of them to be absorbed, thus reducing interference from reflected waves.

[0046] like Figure 2 As shown, the AC excitation module 6 consists of an AC signal generator and a power amplifier (which is the prior art), and provides an excitation signal frequency between 10MHz and 300MHz, with an output power between 400mW and 3W.

[0047] The working principle of the specific implementation method one is as follows: The AC excitation module 6 applies an AC excitation signal between the positive and negative electrodes of the rectangular interdigitated electrode or the arc-shaped interdigitated electrode. Under the action of the alternating electric field, due to the inverse piezoelectric effect, the piezoelectric substrate 1 will induce mechanical distortion inside the crystal lattice due to the displacement of the charge center, converting the high-frequency electrical signal into mechanical vibration of its own frequency. Ultrasonic surface waves propagating along the direction perpendicular to the electrode are excited on the surface of the piezoelectric substrate 1, and enter the microchannel 3-2 through the interface between the microfluidic chip 3 and the piezoelectric substrate 1. The liquid is pre-introduced into the microchannel 3-2. Cleaning fluid 4 is filled into microchannel 3-2 through port 3-1. Under the action of high-frequency vibration, the cleaning fluid 4 forms discontinuous droplets. Ultrasonic surface waves couple into the interior of the cleaning fluid droplets, generating an acoustic flow effect. The energy carried by the sound waves is also coupled to the droplets at a certain angle, converting into the droplets' kinetic energy, driving the cleaning fluid 4 to move along microchannel 3-2. Substances retained inside microchannel 3-2, especially at corners, are drawn into the cleaning fluid 4 under the action of acoustic flow and discharged from the microfluidic chip 3 through liquid outlet 3-3, achieving effective cleaning of the microfluidic chip 3. Changing the amplitude and frequency of the AC excitation signal can quickly adjust the amplitude and frequency of the ultrasonic surface waves, thereby changing the cleaning force and efficiency.

[0048] Specific implementation method two: such as Figure 5 , Figures 11-13 As shown, this embodiment discloses a piezoelectric ultrasonic self-cleaning microfluidic chip, including a piezoelectric ultrasonic generator, a microfluidic chip 3, and a cleaning fluid 4. The microfluidic chip 3 is fixedly mounted on the piezoelectric ultrasonic generator. A microchannel 3-2 is provided inside the microfluidic chip 3, or the microstructure provided at the bottom of the microfluidic chip 3 forms a closed microchannel 3-2 through irreversible sealing with the piezoelectric ultrasonic generator, realizing the bonding of the contact surface and ensuring that the cleaning fluid 4 inside the microfluidic chip 3 does not leak. At least one liquid inlet 3-1 and liquid outlet 3-3 communicating with the microchannel 3-2 are vertically opened on the upper surface of the microfluidic chip 3. The cleaning fluid 4 enters the microchannel 3-2 through the liquid inlet 3-1, flows along the microchannel 3-2, and is discharged through the liquid outlet 3-3.

[0049] The piezoelectric ultrasonic generator includes a piezoelectric ceramic sheet 7, a brass substrate 8 (the piezoelectric ceramic sheet 7 and the brass substrate 8 are combined to form a piezoelectric ceramic transducer), a sound absorption block 5, and an AC excitation module 6. The piezoelectric ceramic sheet 7 and the sound absorption block 5 are both fixed to the upper surface of the brass substrate 8 (the sound absorption block 5 is fixed to the upper surface of the brass substrate 8 by epoxy resin adhesive, and preferably there are two sound absorption blocks 5, which are set at both ends of the upper surface of the brass substrate 8 to absorb ultrasonic waves). The AC excitation module 6 is connected to the piezoelectric ceramic sheet 7 and the brass substrate 8 through the positive and negative poles of the excitation signal leads, respectively. The microfluidic chip 3 is fixed to the upper surface of the brass substrate 8, and the microstructure at the bottom of the microfluidic chip 3 is irreversibly sealed with the upper surface of the brass substrate 8 to form a closed microchannel 3-2.

[0050] In this embodiment, the piezoelectric ultrasonic generator uses a piezoelectric ceramic sheet 7 and a brass substrate 8 instead of the electrode 2 and the piezoelectric substrate 1.

[0051] like Figure 11 As shown, a microchannel 3-2 is set inside the microfluidic chip 3, and the cleaning fluid 4 does not directly contact the brass substrate 8 when it flows through the microchannel 3-2.

[0052] like Figure 13 As shown, a microstructure is set at the bottom of the microfluidic chip 3. The microstructure and the upper surface of the brass substrate 8 are irreversibly sealed to form a closed microchannel 3-2. The cleaning solution 4 in the microchannel 3-2 is in direct contact with the brass substrate 8.

[0053] like Figures 11-13 As shown, the material of the microfluidic chip 3 is one or a combination of several of the following: polydimethylsiloxane, polymethyl methacrylate, glass, and polymer resin.

[0054] like Figures 7-9 As shown, the shape of the microchannel 3-2 is one or a combination of straight line, broken line, and arc shape, such as a 'Y' shaped microchannel (a combination of broken line and straight line microchannels), a broken line microchannel, an arc microchannel, a 'T' shaped microchannel, and a ring microchannel (a combination of straight line and arc microchannels). Figure 10 The diagram shows four types of microchannels integrated on the same microfluidic chip 3. These four types of microchannels are: 'Y'-shaped microchannel, arc-shaped microchannel, zigzag-shaped microchannel, and a combination of straight and arc-shaped microchannels.

[0055] The overall depth of microchannel 3-2 remains consistent; the width of microchannel 3-2 is 0.1mm to 1mm, the depth of microchannel 3-2 is 0.1mm to 0.5mm, and the overall width of microchannel 3-2 may be the same or different.

[0056] At least two microchannels 3-2 are arranged side by side along the length or width of the microfluidic chip 3.

[0057] The cleaning solution 4 is a solution of deionized water, methanol, ethanol, isopropanol, or acetone.

[0058] like Figures 11-13 As shown, the sound-absorbing block 5 is made of rubber, sound-absorbing foam, or glass fiber. This allows ultrasonic waves to enter the sound-absorbing material without reflection and for most of them to be absorbed, thus reducing interference from reflected waves.

[0059] like Figures 11-13 As shown, the AC excitation module 6 consists of an AC signal generator and a power amplifier (which is the prior art), and provides an excitation signal frequency between 10MHz and 300MHz, with an output power between 400mW and 3W.

[0060] The working principle of Specific Implementation Method 2 is the same as that of Specific Implementation Method 1.

Claims

1. A piezoelectric ultrasonic self-cleaning microfluidic chip, characterized in that: The invention comprises a piezoelectric ultrasonic wave generator, a microfluidic chip (3) and a cleaning liquid (4); the microfluidic chip (3) is fixedly mounted on the piezoelectric ultrasonic wave generator; a microchannel (3-2) is arranged inside the microfluidic chip (3); or a microstructure arranged at the bottom of the microfluidic chip (3) and the piezoelectric ultrasonic wave generator are irreversibly sealed to form a closed microchannel (3-2); and the upper surface of the microfluidic chip (3) is provided with at least one liquid inlet (3-1) and a liquid outlet (3-3) connected to the microchannel (3-2); the cleaning liquid (4) enters the microchannel (3-2) through the liquid inlet (3-1), flows along the microchannel (3-2), and is discharged through the liquid outlet (3-3).

2. A piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 1, characterized in that: The piezoelectric ultrasonic generating device comprises a piezoelectric substrate (1), an electrode (2), a sound absorbing block (5) and an AC excitation module (6); the electrode (2) is located at one end of the upper surface of the piezoelectric substrate (1) and the two are made into one body, and the sound absorbing block (5) is fixed on the upper surface of the piezoelectric substrate (1); the AC excitation module (6) is connected to the positive and negative poles of the electrode (2) through a lead wire; the microfluidic chip (3) is fixed on the upper surface of the piezoelectric substrate (1), and the microstructure provided at the bottom of the microfluidic chip (3) and the upper surface of the piezoelectric substrate (1) are irreversibly sealed to form the closed microchannel (3-2).

3. A piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 1, characterized in that: The piezoelectric ultrasonic generating device comprises a piezoelectric ceramic sheet (7), a brass substrate (8), a sound absorbing block (5) and an AC excitation module (6); the piezoelectric ceramic sheet (7) and the sound absorbing block (5) are both fixed on the upper surface of the brass substrate (8), and the AC excitation module (6) is connected to the piezoelectric ceramic sheet (7) and the brass substrate (8) via positive and negative poles of an excitation signal lead, respectively; the microfluidic chip (3) is fixed on the upper surface of the brass substrate (8), and a microstructure provided at the bottom of the microfluidic chip (3) and the upper surface of the brass substrate (8) are irreversibly sealed to form a closed microchannel (3-2).

4. A piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 2, characterized in that: The electrode (2) is formed on one end of the upper surface of the piezoelectric substrate (1) by magnetron sputtering and ion beam etching processes.

5. The piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 2, characterized in that: The piezoelectric substrate (1) is lithium niobate, piezoelectric ceramics or piezoelectric polymer material with a Y-128° tangent, or a composite substrate consisting of glass, metal or plastic non-piezoelectric material and a piezoelectric film with a thickness of 0.2 mm to 1 mm deposited on its surface.

6. The piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 2, characterized in that: The electrode (2) is a rectangular interdigital electrode or an arc-shaped interdigital electrode, and the material of the electrode (2) is one or a combination of gold, platinum, aluminum, silver, FTO conductive glass, titanium, chromium, and carbon.

7. The piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 1, characterized in that: The shape of the microchannel (3-2) is one of a straight line shape, a broken line shape, and an arc shape, or a combination of these shapes; the overall depth of the microchannel (3-2) remains consistent, and the overall width of the microchannel (3-2) is the same or different.

8. A piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 1 or 7, characterized in that: At least two of the microchannels (3-2) are arranged in parallel along the length direction or the width direction of the microfluidic chip (3).

9. The piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 1, characterized in that: The cleaning liquid (4) is deionized water, methanol, ethanol, isopropanol or acetone solution.

10. A piezoelectric ultrasonic self-cleaning microfluidic chip according to claim 2 or 3, characterized in that: The material of the sound absorbing block (5) is rubber, sound absorbing foam or glass fiber.

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