Piezoelectric micropump using synthetic jet principle to increase flow

Abstract

The application discloses a piezoelectric micro-pump using synthetic jet principle to increase flow; the piezoelectric micro-pump comprises a flow inlet layer, a barrier layer, a vibration substrate layer, a first upper power supply layer and a shell layer which are stacked in sequence, and a first vibration layer and a closed cavity layer which are fixed on the side of the vibration substrate layer away from the barrier layer; a flow outlet hole is formed in the center of the shell layer; a jet hole is formed on the closed cavity layer and is aligned with the flow outlet hole; an inner laminated flow cavity is formed between the closed cavity layer and the vibration substrate layer; the jet hole is the only channel for fluid exchange between the inner laminated flow cavity and the outside world; the closed cavity layer is introduced between the vibration substrate layer and the shell layer, and forms the inner laminated flow cavity with the vibration substrate layer; the inner laminated flow cavity only has the jet hole which is aligned with the flow outlet hole of the micro-pump as an inlet and outlet flow channel; the synthetic jet principle is used to significantly increase the flow of the piezoelectric micro-pump.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric gas micropump technology, specifically relating to a piezoelectric micropump that increases flow rate by utilizing the principle of synthetic jet. Background Technology

[0002] In the field of micropumps, the synthetic jet principle, as an important research technique, has attracted widespread attention and exploration. Micropumps, as key devices for the transport and control of minute fluids, have significant application value in medicine, bioanalysis, and chemical reactions. However, due to the small size, complex flow channel characteristics, and fluid viscosity of micropumps, traditional pump design and operating principles face numerous challenges at the microscale. Ensuring high-performance output while pursuing miniaturization is also a challenging goal. The introduction of synthetic jets provides a new approach to addressing these challenges.

[0003] Traditional micropump designs often need to balance pressure drop, flow stability, and flow characteristics at a microscale within tiny channels while maintaining miniaturization. The synthetic jet principle, by mixing high-speed and low-speed fluids, effectively increases the kinetic energy and velocity of the fluid, potentially overcoming these challenges. While pursuing miniaturization, the synthetic jet principle can achieve higher output flow rates, further expanding the potential of micropumps in high-flow-rate applications. This technology not only improves the output flow rate and fluid delivery capacity of micropumps but also enables more precise flow control and fluid mixing, meeting the flow performance requirements of microfluidic applications.

[0004] In the field of micropumps, researchers are actively exploring the application of synthetic jet principles, particularly in research areas pursuing miniaturization and high flow rate output. By rationally designing the geometry, flow channel shape, and synthetic jet parameters of micropumps, their efficiency and performance can be optimized, while simultaneously achieving miniaturization and high flow rate output. Furthermore, the synthetic jet principle can also be used in the design of innovative micropumps, such as mixing multi-channel fluids using synthetic jets, thereby further improving fluid delivery efficiency.

[0005] Synthetic jet technology, based on fluid kinetic energy transfer and mixing, is widely used in various engineering and scientific fields. By rationally mixing high-speed and low-speed fluids, synthetic jets can achieve multiple objectives, such as improving fluid transport efficiency, enhancing combustion reactions, and optimizing liquid atomization and injection. In aerospace, energy, biomedicine, and environmental protection, synthetic jet technology is applied to equipment such as jet engines, combustors, microfluidic systems, and sprayers, providing crucial support for system performance improvement and innovation. Through careful design of the structure and parameters of synthetic jet systems, efficient energy transfer, precise fluid control, and more effective material conversion can be achieved, driving technological progress and engineering development.

[0006] Although the application of synthetic jet principle in micropumps is still in the exploratory stage, its potential advantages and application prospects have already attracted widespread interest in the research community. With the continuous development and innovation of microfluidic technology, synthetic jet principle is expected to provide new solutions for improving the performance, miniaturization, and high flow rate output of micropumps, and promote the further development and application of micropump technology in fields such as medicine, biology, and chemistry. Summary of the Invention

[0007] The purpose of this invention is to propose a piezoelectric micropump that increases flow rate by utilizing the principle of synthetic jet, thereby achieving a pump body structure with higher quality and greater precision, while also improving the stability and sealing of the micropump.

[0008] This invention provides a piezoelectric micropump that increases flow rate using the principle of synthetic jet, comprising a flow inlet layer, a barrier layer, a vibrating substrate layer, a first upper power supply layer, and a shell layer stacked sequentially, as well as a first vibrating layer and a closed cavity layer fixed to the side of the vibrating substrate layer opposite to the barrier layer. An outlet hole is formed at the center of the shell layer; a jet hole aligned with the outlet hole is formed on the closed cavity layer. An inner confluence cavity is formed between the closed cavity layer and the vibrating substrate layer; the jet hole is the only channel for fluid exchange between the inner confluence cavity and the outside environment.

[0009] During operation, the first upper power supply layer and the barrier layer form the two poles for powering the first vibration layer; the closed cavity layer deforms along with the vibration of the vibration substrate layer, causing the volume of the inner confluence cavity to change periodically, forming a synthetic jet phenomenon at the outlet hole.

[0010] Preferably, the diameter d of the inner confluence cavity is 8mm to 11mm; and the diameter d0 of the jet orifice is 1mm to 2mm.

[0011] Preferably, the first vibration layer is located inside the inner confluence cavity; the inner edge of the first upper power supply layer is connected to a first terminal; the first terminal passes through the side wall of the closed cavity layer, extends into the inner confluence cavity, and is electrically connected to the side of the first vibration layer away from the vibration substrate layer.

[0012] Preferably, the piezoelectric micropump that increases flow rate using the principle of synthetic jet also includes a second vibrating layer and a second upper power supply layer. The second vibrating layer is fixed on the enclosed cavity layer and is located on the side of the enclosed cavity layer opposite to the vibrating substrate layer. The second upper power supply layer is disposed between the first upper power supply layer and the shell layer; the first upper power supply layer and the barrier layer form the two poles for supplying power to the second vibrating layer.

[0013] Preferably, the inner edge of the second upper power supply layer is connected to a second terminal; the second terminal extends to the second vibration layer and is electrically connected to the side of the second vibration layer away from the closed cavity layer.

[0014] Preferably, both the first and second vibration layers are made of piezoelectric ceramics.

[0015] Preferably, a reinforcing layer is provided on the side of the vibrating substrate layer facing the barrier layer; a central through-hole aligned with the reinforcing layer is formed on the barrier layer; the central through-hole on the barrier layer is in the form of a two-stage stepped hole, including a first segment near the inlet layer and a second segment near the vibrating substrate layer. The diameter of the first segment is larger than the diameter of the second segment and smaller than the diameter of the reinforcing layer. A stepped surface is formed at the connection between the first segment and the second segment; a sheet-like elastic deformation structure is formed between the stepped surface and the side of the barrier layer facing the vibrating substrate layer; the thickness of the sheet-like elastic deformation structure is 40μm-60μm.

[0016] Preferably, the reinforcing layer and the central vibrating part of the vibrating substrate layer are integrally formed.

[0017] Preferably, the vibrating substrate layer includes an edge fixing portion, elastic connectors, and a central vibrating portion. The edge of the central hole in the edge fixing portion is connected to the outer edge of the central vibrating portion via multiple elastic connectors. A reinforcing layer and a sealing cavity layer are respectively disposed on opposite sides of the central vibrating portion of the vibrating substrate layer.

[0018] Preferably, the elastic connector is made of a flexible metal strip, comprising a first connecting portion, a second connecting portion, and an elastic segment. One end of the first connecting portion is connected to the central vibrating portion, and the other end of the first connecting portion is connected to one end of the elastic segment. One end of the second connecting portion is connected to the other end of the elastic segment; the other end of the second connecting portion is connected to the edge fixing portion. The elastic segment is arc-shaped.

[0019] The beneficial effects of this invention are:

[0020] 1. The present invention introduces a closed cavity layer between the vibrating substrate layer and the shell layer, which forms an inner confluence cavity with the vibrating substrate layer; the inner confluence cavity has only jet holes aligned with the micropump outlet as inlet and outlet channels, and by utilizing the principle of synthetic jet, the flow rate of the piezoelectric micropump is significantly increased.

[0021] 2. The present invention provides a vibration layer on both the vibration substrate layer and the closed cavity layer, which can adapt to different application scenarios. By adjusting the parameters of the synthetic jet, the micropump can achieve precise flow control.

[0022] 3. This invention enables pulsed fluid ejection through high-frequency vibration of the piezoelectric layer, thereby achieving unidirectional high-quality flow delivery of fluid. Attached Figure Description

[0023] Figure 1 This is a cross-sectional structural diagram of Embodiment 1 of the present invention;

[0024] Figure 2This is the first exploded view diagram of Embodiment 1 of the present invention;

[0025] Figure 3 This is the second exploded view diagram of Embodiment 1 of the present invention;

[0026] Figure 4a This is a modal diagram of the downward motion of the piezoelectric vibrator in Embodiment 1 of the present invention;

[0027] Figure 4b This is a schematic diagram showing the deformation of the vibrating substrate layer and the enclosed cavity layer when the piezoelectric vibrator moves downward in Embodiment 1 of the present invention;

[0028] Figure 5a This is a modal diagram of the upward motion of the piezoelectric vibrator in Embodiment 1 of the present invention;

[0029] Figure 5b This is a schematic diagram showing the deformation of the vibrating substrate layer and the enclosed cavity layer when the piezoelectric vibrator moves upward in Embodiment 1 of the present invention;

[0030] Figure 6 This is a schematic diagram of the internal structure of Embodiment 2 of the present invention; Detailed Implementation

[0031] The first embodiment of the present invention will be further described below with reference to the accompanying drawings.

[0032] Example 1

[0033] like Figure 1 , 2 As shown in Figure 3, a piezoelectric micropump that increases flow rate using the principle of synthetic jet includes an inlet layer 100, a barrier layer 200, a vibrating substrate layer 300, a first vibrating layer 400, a sealed cavity layer 500, a second vibrating layer 600, a first upper power supply layer 700, a second upper power supply layer 800, and a shell layer 900. The inlet layer 100, barrier layer 200, vibrating substrate layer 300, first upper power supply layer 700, second upper power supply layer 800, and shell layer 900 are stacked sequentially. A reinforcing layer 301 is provided on the side of the vibrating substrate layer 300 facing the barrier layer 200.

[0034] An input cavity A is formed between the inlet layer 100 and the barrier layer 200; a transition cavity B is formed between the barrier layer 200 and the vibrating substrate layer 300; and an output cavity C is formed between the vibrating substrate layer 300 and the housing layer 900. An inlet hole 101 is provided on the inlet layer 100; an outlet hole 901 is provided on the housing layer 900; a reinforcing layer 301 is located in the transition cavity B and is fixed to the vibrating substrate layer 300; and a closed cavity layer 500, a first vibrating layer 400, and a second vibrating layer 600 are all disposed in the output cavity C.

[0035] The enclosed cavity layer 500 includes a sequentially formed annular lifting section and a jet sealing section. The annular lifting section is circular, and its edge is fixed to the side of the vibrating substrate layer 300 facing the output cavity C. The annular lifting section is used to create a gap between the jet sealing section and the vibrating substrate layer 300. A jet hole 501 is provided at the center of the jet sealing section. An inner confluence cavity 502 is formed between the jet sealing section of the enclosed cavity layer 500 and the vibrating substrate layer 300; the jet hole 501 is the only inlet and outlet of the inner confluence cavity 502 and is aligned with the outlet hole 901. The first vibrating layer 400 is fixed to the side of the vibrating substrate layer 300 facing the output cavity C and is located in the inner confluence cavity 502; the second vibrating layer 600 is fixed on the jet sealing section of the enclosed cavity layer 500 and does not block the jet hole 501.

[0036] A first terminal 701 is connected to the inner edge of the first upper power supply layer 700. The first terminal 701 passes through the side wall of the enclosed cavity layer 500, extends into the inner confluence cavity 502, and is welded to the node (the point of minimum vibration) on the side of the first vibration layer 400 away from the vibration substrate layer 300, which can greatly improve the stability of the device and form an electrical connection. The connection between the first terminal 701 and the enclosed cavity layer 500 is insulated and sealed.

[0037] The inner edge of the second upper power supply layer 800 is connected to a second terminal 801; the second terminal 801 extends to the second vibration layer 600 and is welded to the node of the second vibration layer 600 to form an electrical connection.

[0038] The first upper power supply layer 700 and the second upper power supply layer 800 are separated by a padding layer. In some embodiments, the padding layer is made of insulating material to facilitate independent control of the two vibration layers.

[0039] The sides of the first vibration layer 400 and the second vibration layer 600 facing away from the outlet hole 901 are electrically connected together through a conductive closed cavity layer 500 and a vibration substrate layer 300, and are led out from the barrier layer 200 to form a first control interface. The sides of the first vibration layer 400 and the second vibration layer 600 near the outlet hole 901 are led out through a first upper power supply layer 700 and a second upper power supply layer 800, respectively, to form a second control interface. Independent vibration control of the first vibration layer 400 and the second vibration layer 600 is achieved through these three control interfaces.

[0040] Input cavity A and transition cavity B are connected by a central through-hole 201 on the barrier layer 200; the reinforcing layer 301 is aligned with the central through-hole 201 on the barrier layer 200. The central through-hole 201 on the barrier layer 200 is a two-stage stepped hole, including a first segment near input cavity A and a second segment near transition cavity B. The diameter of the first segment is larger than the diameter of the second segment and smaller than the diameter of the reinforcing layer 301. The diameter of the second segment is 5mm to 7mm. A stepped surface is formed at the connection between the first and second segments; a sheet-like elastic deformation structure is formed between this stepped surface and the side of the barrier layer 200 facing the transition cavity B; the thickness of this sheet-like elastic deformation structure is 40μm-60μm (its thickness is drawn larger in the figure to highlight the existence of the sheet-like elastic deformation structure, and its actual thickness is much smaller than that of the inlet layer 100), exhibiting good elasticity and capable of replacing the buffer layer in a conventional piezoelectric micropump.

[0041] The vibrating substrate layer 300 includes an edge fixing portion, elastic connectors, and a central vibrating portion. The edge of the central hole in the edge fixing portion is connected to the outer edge of the central vibrating portion via the elastic connector. The elastic connector includes a first connecting portion, a second connecting portion, and an elastic segment. One end of the first connecting portion is connected to the central vibrating portion, and the other end is connected to one end of the elastic segment. One end of the second connecting portion is connected to the other end of the elastic segment; the other end of the second connecting portion is connected to the edge fixing portion. The elastic connector is an elastic and non-linear metal strip. The central vibrating portion of the vibrating substrate layer 300 is elastically supported at four connection points of the edge fixing portion by four elastic connectors (each elastic connector is distributed at 90 degrees); thus allowing the central vibrating portion to vibrate up and down relative to the edge fixing portion. A reinforcing layer 301 and a closed cavity layer 500 are respectively disposed on opposite sides of the central vibrating portion of the vibrating substrate layer 300.

[0042] The outer contour diameter, thickness and material of the first vibration layer 400 and the second vibration layer 600 are the same; the outer contour diameter is 3mm-6mm; the thickness is 50μm-300μm; the material is one or more of aluminum nitride, scandium-doped aluminum nitride, zinc oxide, lithium nickelate or lead zirconate titanate, preferably PZT4.

[0043] The first vibration layer 400 and the vibration substrate layer 300, as well as the second vibration layer 600 and the enclosed cavity layer 500, are bonded together with single-component or two-component epoxy resin adhesive.

[0044] The diameter of the closed cavity layer 500 is 8mm to 11mm, the thickness is 30μm to 50μm, and the material is one or more of copper, silver, aluminum, and aluminum alloy. The diameter of the jet hole 501 is 1mm to 2mm, and it is smaller than the diameter of the outlet hole 901.

[0045] The downward and upward movements of the piezoelectric oscillator in the micropump are shown in Figures 4 and 5. It is easy to see that when the piezoelectric oscillator moves downward, the double-layer piezoelectric structure allows for a greater volume change in the inner confluence cavity 502. Similarly, when the piezoelectric oscillator moves upward, the compressed gas achieves a greater effect.

[0046] The working principle of this piezoelectric micropump, which utilizes the principle of synthetic jet to increase flow rate, is as follows:

[0047] When the micropump operates, a first electrical signal, a second electrical signal, and a third electrical signal are respectively supplied to the barrier layer 200, the first upper power supply layer 700, and the second upper power supply layer 800. The first, second, and third electrical signals are all rectangular waves with a peak value of 10-40Vpp, and the driving frequency is set to the first-order resonant frequency (approximately 23KHz). The phase difference between the first and second electrical signals is 180°. The phases of the second and third electrical signals are the same. This causes the first vibration layer 400 and the second vibration layer 600 to vibrate synchronously and in the same direction. The central vibration part of the vibration substrate layer 300 moves up and down reciprocally under the drive of the first vibration layer 400, causing the transition cavity B and the output cavity C to change periodically, thereby performing periodic pumping.

[0048] The operation of a micropump can be divided into four stages within a single working cycle.

[0049] Phase 1: As Figure 4a and 4b As shown, the piezoelectric oscillator moves downward from the equilibrium state (i.e., towards the direction of the barrier layer 200), and the reinforcing layer 301 on the back of the oscillator blocks the flow hole 104, so that the gas is very small or not easy to flow out of the flow hole 104; but at this time, the volume of the inner confluence cavity 502 increases (as shown in Figure 4), and the gas is drawn into the inner confluence cavity 502 from the jet hole 501.

[0050] Second stage: The piezoelectric oscillator moves upward from the bottom to the equilibrium state. At this time, the volume of the inner confluence cavity 502 decreases, and the gas in the inner confluence cavity 502 is discharged outward through the jet hole 501, resulting in a net gas outflow.

[0051] Phase Three: As Figure 5a and 5b As shown, the piezoelectric vibrator moves upward from the equilibrium state to the top. At this time, the volume of the inner confluence cavity 502 is further reduced, and the gas continues to flow out net. However, since the upward movement of the vibrating substrate layer 300 is more intense than that of the first vibrating layer 400 (as shown in Figure 5), the upward vibration can compress the gas more, and a large amount of gas flows out from the jet hole 501 and the outlet hole 901.

[0052] Fourth stage: The piezoelectric oscillator moves downwards from the top to an equilibrium state, and gas is drawn into the cavity. However, due to the large amount of air discharged during the exhaust process moving towards the outlet at a high speed, a large amount of gas is drawn back to both sides and will not be drawn back into the pump cavity. During this alternating process of intake and exhaust, the gas near the jet orifice 501 is subjected to strong shearing action, which in turn forms a pair of vortices rotating in opposite directions.

[0053] When the next working cycle begins, the vortex pairs generated in the third stage have moved away from the jet orifice 501 and therefore will not be drawn back into the cavity. The fluid in the transformer chamber is input into the output channel. This cyclical action creates a series of vortex pairs, thereby increasing the flow rate near the output orifice.

[0054] Therefore, by applying a periodic alternating voltage to the piezoelectric vibrator, the fluid can be transported unidirectionally within the cavity, and a high-quality, high-flow-rate unidirectional flow can be continuously generated at the outlet orifice 901.

[0055] According to the experimental results of this invention, the piezoelectric micropump structure that increases flow rate by utilizing the principle of synthetic jet can achieve a flow rate of 500 ml / min, which is significantly higher than the 300 ml / min that can only be achieved by the common single piezoelectric layer structure.

[0056] The following formulas provide constraints for the structure, such as the relationships between its dimensions:

[0057] In this invention, the formation of the synthetic jet phenomenon is influenced by two dimensionless parameters: the dimensionless stroke length L and the Reynolds number Re. The specific expressions for the dimensionless stroke length L and the Reynolds number Re are as follows:

[0058]

[0059]

[0060] Where d is the jet orifice diameter, d0 is the diameter of the enclosed cavity layer, l is the stroke length, and T is the period. The average velocity at the jet orifice within one cycle is given by , K is a constant that includes the material properties and structural dimensions of the piezoelectric material, U is the input voltage, v is the kinematic viscosity, and f0 is the operating frequency.

[0061] The above formulas reveal that the dimensionless stroke length is proportional to the amplitude of the piezoelectric oscillator; the Reynolds number is proportional to both the amplitude and operating frequency of the piezoelectric oscillator. Furthermore, calculations show that the Reynolds number of the existing structure is between 2600 and 3800, significantly higher than the boundary condition for tidal flow formation (Re > 2000). Therefore, it can be concluded that the operating state of the piezoelectric oscillator determines the output performance of the synthetic jet device.

[0062] Furthermore, the specific expression of the discriminant for synthetic jet formation is given:

[0063]

[0064] Where S is the Stokes number.

[0065] Given a fixed piezoelectric oscillator amplitude, enclosed cavity, and jet orifice size, this formula can be used to preliminarily determine whether the synthetic jet phenomenon can be formed normally, providing theoretical guidance for the processing of actual prototypes. The parameter requirements of this device are much greater than those of the discriminant formula for synthetic jets.

[0066] The following is a brief explanation of the application of the synthetic jet principle in this invention:

[0067] The dimensionless stroke length L is defined as follows:

[0068]

[0069] Where d is the jet orifice diameter, and l is the length of the fluid column discharged in one cycle of the composite jet, i.e., the stroke length, which is defined as follows:

[0070]

[0071] Where T is the period. The average velocity at the jet orifice during one cycle is defined as follows:

[0072]

[0073] Where s is the cross-sectional area of ​​the jet orifice, v(r,t) is the velocity distribution of the oscillator, and r is the radius of the closed cavity.

[0074] The Reynolds number Re is defined as follows:

[0075]

[0076] Where v is the kinematic viscosity.

[0077] The Stokes number S is defined as:

[0078]

[0079] Where ω = 2πf is the angular frequency of the oscillator.

[0080] The dimensionless stroke length L is proportional to the reciprocal of the Strauhal number St, from which we can obtain the following formula:

[0081]

[0082] In summary, the following equation must be satisfied to form a synthetic jet phenomenon, which is also a prerequisite for designing piezoelectric micropumps using the synthetic jet principle:

[0083]

[0084] Generally speaking, when the value of the constant C is greater than 2, we consider that the conditions for forming a synthetic jet have been met.

[0085] In this invention, the diameter d of the inner confluence cavity is 8mm to 11mm, and the diameter d0 of the jet hole opened on it is 1mm to 2mm. Under the driving of a peak-to-peak voltage U of 40Vpp and a frequency f0 of 23KHz, the obtained constant C can reach about 15-20, which meets the conditions for the formation of the synthetic jet.

[0086] Example 2

[0087] A piezoelectric micropump that increases flow rate by utilizing the principle of synthetic jets. The difference between this embodiment and Embodiment 1 is that the second vibration layer and the second upper power supply layer are omitted.

[0088] like Figure 6 As shown, in this embodiment, the first vibration layer 400 is fixed on the side of the vibration substrate layer 300 away from the barrier layer 200. The first vibration layer 400 and the vibration substrate layer 300 are also bonded together with a single-component or two-component epoxy resin adhesive.

[0089] When a rectangular wave signal with a peak value of 20Vpp, a first-order resonant frequency (around 23kHz), and a phase difference of 180° is applied to the first vibration layer 400, the changes in intracavity pressure and volume are the same as in Example 1, achieving the same flow effect as in Example 1. Furthermore, eliminating the second vibration layer and the second upper power supply layer reduces the number of layers in the micropump, making the overall structure of the micropump more compact.

Claims

1. A piezoelectric micropump that increases flow rate using the principle of synthetic jet, comprising a flow inlet layer (100), a barrier layer (200), a vibrating substrate layer (300), a first upper power supply layer (700), and a housing layer (900) stacked sequentially, and a first vibrating layer (400) fixed on the side of the vibrating substrate layer (300) facing away from the barrier layer (200); characterized in that: It also includes a closed cavity layer (500) fixed on the side of the vibrating substrate layer (300) away from the barrier layer (200); an outlet hole (901) is opened at the center of the shell layer (900); a jet hole (501) aligned with the outlet hole (901) is opened on the closed cavity layer (500); an inner confluence cavity (502) is formed between the closed cavity layer (500) and the vibrating substrate layer (300); the jet hole (501) is the only channel for fluid exchange between the inner confluence cavity (502) and the outside; the first vibrating layer (400) is located inside the inner confluence cavity (502); The vibrating substrate layer (300) has a reinforcing layer (301) on its side facing the barrier layer (200); a central through hole (201) aligned with the reinforcing layer (301) is formed on the barrier layer (200); the central through hole (201) on the barrier layer (200) is in the form of a two-stage stepped hole, including a first hole segment near the inlet layer (100) and a second hole segment near the vibrating substrate layer (300); the diameter of the first hole segment is larger than the diameter of the second hole segment and smaller than the diameter of the reinforcing layer (301); a stepped surface is formed at the connection between the first hole segment and the second hole segment; a sheet-like elastic deformation structure is formed between the stepped surface and the side of the barrier layer (200) facing the vibrating substrate layer (300); the thickness of the sheet-like elastic deformation structure is 40μm-60μm; During operation, the first upper power supply layer (700) and the barrier layer (200) form the two poles for powering the first vibration layer (400); the closed cavity layer (500) deforms along with the vibration substrate layer (300), causing the volume of the inner confluence cavity (502) to change periodically, forming a synthetic jet phenomenon at the outlet hole (901).

2. The piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 1, characterized in that: The diameter d of the inner confluence cavity (502) is 8mm to 11mm; the diameter d0 of the jet hole (501) is 1mm to 2mm.

3. A piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 1, characterized in that: The inner edge of the first upper power supply layer (700) is connected to a first terminal (701); the first terminal (701) passes through the side wall of the closed cavity layer (500), extends into the inner confluence cavity (502), and is electrically connected to the side of the first vibration layer (400) away from the vibration substrate layer (300).

4. A piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 1, characterized in that: It also includes a second vibration layer (600) and a second upper power supply layer (800); the second vibration layer (600) is fixed on the closed cavity layer (500) and is located on the side of the closed cavity layer (500) away from the vibration substrate layer (300); the second upper power supply layer (800) is disposed between the first upper power supply layer (700) and the shell layer (900); the first upper power supply layer (700) and the barrier layer (200) form the two poles for powering the second vibration layer (600).

5. A piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 4, characterized in that: The inner edge of the second upper power supply layer (800) is connected to a second terminal (801); the second terminal (801) extends to the second vibration layer (600) and is electrically connected to the side of the second vibration layer (600) away from the closed cavity layer (500).

6. A piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 4, characterized in that: Both the first vibration layer (400) and the second vibration layer (600) are made of piezoelectric ceramics.

7. A piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 1, characterized in that: The reinforcing layer (301) and the central vibration part of the vibration substrate layer (300) are integrally formed.

8. A piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 1, characterized in that: The vibrating substrate layer (300) includes an edge fixing part, an elastic connector and a central vibrating part; the edge of the central hole of the edge fixing part and the outer edge of the central vibrating part are connected by a plurality of elastic connectors; the reinforcing layer (301) and the closed cavity layer (500) are respectively disposed on opposite sides of the central vibrating part of the vibrating substrate layer (300).

9. A piezoelectric micropump for increasing flow rate using the principle of synthetic jet as described in claim 8, characterized in that: The elastic connector is made of a flexible metal strip and includes a first connecting part, a second connecting part, and an elastic segment; one end of the first connecting part is connected to the central vibration part, and the other end of the first connecting part is connected to one end of the elastic segment; one end of the second connecting part is connected to the other end of the elastic segment; the other end of the second connecting part is connected to the edge fixing part; the elastic segment is arc-shaped.

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