One-way piezoelectric MEMS active valve and application

Abstract

The invention discloses a one-way piezoelectric MEMS active valve and application, and belongs to the technical field of fluid control. The one-way piezoelectric MEMS active valve comprises a non-piezoelectric actuating structural member and at least one piezoelectric actuating structural member; the non-piezoelectric actuating structural member comprises a valve body or further comprises other auxiliary structures of the non-valve body, and the valve body serves as an outer frame part of the valve; the piezoelectric actuating structural member is supported by the valve body or is supported by other auxiliary structures which are not the valve body, and after the piezoelectric actuating structural member is fixed, the unclamped part of the piezoelectric actuating structural member forms a movable piezoelectric actuating structural member; a flow channel of the valve is formed by gaps between piezoelectric actuating structural members and non-piezoelectric actuating structural members, and when a plurality of piezoelectric actuating structural members exist, the flow channel can also be formed by the gaps between the piezoelectric actuating structural members. High-frequency one-way flow control is adopted, and accurate high-frequency (such as ultrasonic frequency band) fluid or sound wave one-way flow control is realized by using the quick response and high-frequency characteristics of the piezoelectric film material.

Description

Technical Field

[0001] This invention belongs to the field of fluid control technology, and in particular relates to a unidirectional piezoelectric MEMS active valve and its application. Background Technology

[0002] In the field of fluid control, valves are key components, widely used in industrial process control, microfluidic systems, and biomedical devices. Traditional valves typically rely on mechanical actuation, such as solenoid valves and pneumatic valves. While these valves are mature technologies, they have some significant drawbacks: complex structure (traditional valves usually consist of multiple mechanical parts, resulting in a complex overall structure and high manufacturing costs); slow response speed (due to mechanical inertia, traditional valves have a slow response speed when opening and closing, making them unsuitable for applications requiring rapid switching); high energy consumption (solenoid and pneumatic valves often require continuous power to maintain an open or closed state, resulting in high energy consumption); and large size (traditional valves are bulky and difficult to apply in space-constrained micro-systems).

[0003] With the development of Microelectromechanical Systems (MEMS) technology, piezoelectric materials have attracted widespread attention in the field of microfluidics due to their excellent electro-actuation properties. Piezoelectric materials are divided into two categories: natural and synthetic. Natural piezoelectric materials such as quartz and crystal are commonly used in high-precision frequency control devices, while synthetic piezoelectric materials such as barium titanate (BaTiO3) and lead zirconate titanate (PZT) possess excellent piezoelectric properties and are widely used in industry. Piezoelectric thin films, prepared by depositing piezoelectric materials in thin film form (at a very low density), often on substrates such as silicon and glass, enable efficient energy conversion of the piezoelectric effect at a microscale, making them an ideal driving method for micro-devices. Piezoelectric thin films offer the following advantages: fast response (piezoelectric materials can rapidly deform under an electric field, enabling rapid control); low energy consumption (they can maintain their deformed state without continuous power supply); high precision (the deformation of piezoelectric materials can be finely adjusted by precisely controlling the voltage); and miniaturization (suitable for integration into micro-devices, meeting the needs of microfluidic systems).

[0004] However, in existing technologies, effectively applying piezoelectric films to valve applications still faces several challenges, such as film integration processes, optimization of driving voltage, and improving deformation transfer efficiency. Furthermore, in some fluid control applications, fluid needs to be controlled to flow unidirectionally in one direction to reduce backflow. This requires the piezoelectric film to move in the desired flow direction to facilitate fluid opening and flow along the flow path. Therefore, it is necessary to propose a unidirectional flow control valve based on piezoelectric films to meet the needs of more application scenarios.

[0005] Existing solutions:

[0006] I. Traditional valve design: Mechanical valves used to control fluid flow or sound waves usually rely on complex mechanical structures and components, such as springs, pistons and other mechanical parts for operation.

[0007] II. Passive and static seals: These are fixed seals used to block or allow fluid flow, such as closed cantilever passive valves, ball valves, umbrella valves, etc. They achieve unidirectional fluid flow control through the interaction between the special arrangement of the valve body and the fluid flow direction.

[0008] Third, valve structures based on piezoelectric films represent a high-precision technology, and patents and designs for this product are relatively scarce in China. These valves are active control valves, while current solutions in the field of microfluidic control mostly use passive valves.

[0009] Problems with existing solutions:

[0010] (a) Size and weight: The mechanical components of traditional valve designs are generally large, which increases the overall size and weight of the equipment. They are not suitable for the miniaturization requirements of modern portable devices and cannot be used in small electronic mobile devices such as headphones and mobile phones.

[0011] (ii) Slow response speed: Passive valves have high opening pressure and require response time, which makes it difficult for the valve to respond quickly in application. In addition, the intake or exhaust gas caused by the vibration of the actuator changes the volume of the cavity has a phase lag with the valve, which affects the performance of the equipment.

[0012] (iii) Weak high-frequency switching performance: In particular, the opening and closing of valves requires ultrasonic frequency bands, or even GHz frequency bands, which existing electromagnetic and pneumatic valves cannot meet.

[0013] (iv) Complexity and reliability: The complex mechanical design increases the risk of failure and the maintenance cost is high. Furthermore, passive valves are only suitable for low-frequency opening and closing. Under high-frequency operation, the service life of the valves is short, and their reliability is insufficient for use at high speeds.

[0014] (v) Low flexibility: The fixed structure of passive valves makes it impossible to dynamically adjust the flow of microfluids according to needs, making it difficult to achieve precise control of fluid or sound wave flow.

[0015] (vi) High energy consumption: Traditional mechanical valves require more energy to drive the movement of components, such as electromagnetic or pneumatic valves, which is not conducive to energy efficiency management of portable devices. Summary of the Invention

[0016] This invention provides a unidirectional piezoelectric MEMS active valve and its application to solve the problems in the prior art.

[0017] The present invention employs the following technical solution: a unidirectional piezoelectric MEMS active valve, comprising a non-piezoelectric actuation structure and at least one piezoelectric actuation structure; the non-piezoelectric actuation structure includes a valve body, or may also include other auxiliary structures not related to the valve body, the valve body serving as the outer frame of the valve to ensure structural stability; the piezoelectric actuation structure is supported by the valve body, or by other auxiliary structures not related to the valve body, and after the piezoelectric actuation structure is fixed, its unsupported portion forms a movable piezoelectric actuation structure; the flow channel of the valve is composed of the piezoelectric actuation structure and the non-piezoelectric actuation structure. A gap is formed between the actuating structural components, and the valve body or auxiliary structure is designed with a recessed structure to form the gap; when there are multiple piezoelectric actuating structural components, the gap between the piezoelectric actuating structural components can also be formed; the average flow resistance of the valve flow channel formed by the gap in one direction is less than the average flow resistance in the opposite direction, so that the fluid presents a unidirectional flow control effect in an average sense; the piezoelectric actuating structure at least includes a piezoelectric material layer, and applying voltage to the piezoelectric actuating structural component causes it to generate displacement to control the opening and closing of the valve, thereby realizing the unidirectional opening and flow control of the valve for the fluid.

[0018] Furthermore, the other auxiliary structures not related to the valve body may or may not be present; when there are no auxiliary structures, the piezoelectric actuation structure is fixed to the valve body; when there are auxiliary structures, the piezoelectric actuation structure may be fixed to the auxiliary structure or fixed to the valve body. When it is fixed to the valve body, the non-piezoelectric actuation auxiliary structure has a recessed structure.

[0019] Furthermore, the piezoelectric actuation structure is fixed to the valve body by peripheral support or to other auxiliary structures outside the valve body by intermediate support, forming actuation structures with different displacement forms.

[0020] Furthermore, the number of other auxiliary structures used to support and fix the piezoelectric actuation structure can be one or more. When there are multiple auxiliary structures, they are used to fix the piezoelectric actuation structure respectively.

[0021] Furthermore, the piezoelectric actuation structure is one of the following shapes: conical, trapezoidal, rectangular, or fan-shaped.

[0022] Furthermore, the piezoelectric actuation structure has an upper electrode and a lower electrode made of metal material on the upper and lower surfaces of the piezoelectric material layer. A diaphragm layer is connected to the surface of the upper or lower electrode, and the diaphragm layer is made of non-active material, which makes the displacement of the piezoelectric actuation structure larger.

[0023] Furthermore, the multiple piezoelectric actuation structural components can be arranged in parallel with fixed supports on the same side or on opposite sides, or in a combination of fixed supports on the same side and on opposite sides.

[0024] Furthermore, the plurality of the piezoelectric actuation structures can be distributed in a rotationally symmetrical manner, or in a left-right / up-down mirror arrangement.

[0025] Furthermore, the flow resistance when the displacement direction of the piezoelectric actuation structure is consistent with the direction of fluid flow is less than the flow resistance when the two directions are inconsistent. This makes the average flow resistance of the fluid flowing in the consistent direction less than the average flow resistance of the fluid flowing in the opposite direction. The valve can realize unidirectional opening and flow control of the fluid along the consistent direction.

[0026] Furthermore, at least one piezoelectric actuation structure wherein a first actuation structure is subjected to a voltage to generate a displacement toward a first direction toward the flow channel, and adjacent actuation structures of this piezoelectric actuation structure are displaced in the same direction as the first direction, or remain stationary, to ensure the unidirectionality of fluid flow.

[0027] Furthermore, the piezoelectric actuation structure is in a flat state when at rest, and the valve is normally closed. The displacement generated by each piezoelectric actuation structure causes the valve to change from closed to open, allowing fluid to flow unidirectionally through the valve opening.

[0028] Furthermore, after the piezoelectric actuation component is displaced by the applied voltage, the displacement of the piezoelectric actuation component can measure the size of the opening. Applying different voltages can control the size of the displacement, and the voltage can be controlled in a more precise manner. Therefore, the valve can achieve stepless adjustment of the size of the flow channel opening.

[0029] Furthermore, the structural components that support and fix the piezoelectric actuation components are made of silicon, glass, or polymer materials and are formed through microfabrication techniques (such as etching and coating).

[0030] Furthermore, the valve body, as the outer frame of the valve, works in conjunction with the piezoelectric actuation structure to limit the size of the initial gap of the valve, and must maintain internal sealing to prevent fluid leakage and ensure the reliability of the structure.

[0031] An application of a unidirectional piezoelectric MEMS active valve is available in electronic devices such as miniature heat sinks, bone conduction headphones, bone conduction glasses, wired headphones, wireless headphones, smartwatches, smart bracelets, AR glasses, VR glasses, and biomedical infusion pumps, or in other scenarios where perfect alternation between sealing and opening is desired.

[0032] The above-described at least one technical solution adopted in the embodiments of the present invention can achieve the following beneficial effects:

[0033] 1. High-frequency unidirectional flow control: Utilizing the fast response and high-frequency characteristics of piezoelectric thin film materials, precise unidirectional flow control of fluids or sound waves at high frequencies (e.g., ultrasonic bands) can be achieved.

[0034] 2. Suitable for miniaturized electronic devices, the design of microelectromechanical systems (MEMS) is well-suited to the miniaturization needs of modern portable devices.

[0035] 3. It is highly flexible, making it easy to achieve quantitative control of fluids or sound waves. The opening and closing status and opening degree of the valve can be adjusted to adapt to different operating conditions.

[0036] 4. High energy efficiency: Using piezoelectric materials as moving parts can reduce energy consumption, achieve efficient valve operation, and alleviate the high load requirements brought about by the high performance of modern electronic devices.

[0037] 5. Improved reliability: The reduced number of mechanical parts and simpler assembly of this active valve lowers the risk of failure. Furthermore, its non-contact opening and closing action enhances the long-term reliability of the equipment. These characteristics give it a significant advantage in portable electronic devices. Attached Figure Description

[0038] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0039] Figure 1 This is a top view of valve embodiment 1 in this invention;

[0040] Figure 2 This is a cross-sectional view of the valve obtained along section line AA;

[0041] Figure 3 This is a simulation result of the overall three-dimensional structure of the valve;

[0042] Figure 4 for Figure 3 The result of a cross-section along the zx-axis plane of the overall structure;

[0043] Figure 5 This is a top view of valve embodiment 2 in this invention;

[0044] Figure 6 and Figure 7 These are cross-sectional views of the valve obtained along section lines BB and CC, respectively.

[0045] Figure 8 The results are the simulation results of the overall three-dimensional structure of the valve;

[0046] Figure 9 for Figure 8 The result of a cross-section along the zy-axis plane of the overall structure;

[0047] Figure 10 This is a top view of valve embodiment 3 in this invention;

[0048] Figure 11 and Figure 12 These are cross-sectional views of the valve obtained along section lines DD and EE, respectively.

[0049] Figure 13 and Figure 14 The image shows the results of a three-dimensional finite element simulation when the valve is in the open state.

[0050] Figure 15 This is a top view of valve embodiment 4 in this invention;

[0051] Figure 16 and Figure 17 The diagram shows the finite element simulation results of the valve in two open states.

[0052] Figure 18 This is a top view of valve embodiment 5 in this invention;

[0053] Figure 19 and Figure 20 Here are the cross-sectional views of the valve obtained along section lines GG and HH, respectively.

[0054] Figure 21 A schematic diagram of the cross section obtained along section line GG when the piezoelectric actuated structure is in a vibrating state;

[0055] Figure 22 This is a top view of valve embodiment 6 in this invention;

[0056] Figure 23 This is a cross-sectional view of the valve obtained along section line II;

[0057] Figure 24 This is a simulation result of the overall three-dimensional structure of the valve;

[0058] Figure 25 for Figure 24 The result of a cross-section along the zx-axis plane of the overall structure;

[0059] Figure 26 This is a top view of valve embodiment 7 in this invention;

[0060] Figure 27 This is a cross-sectional view of the valve obtained along section line JJ.

[0061] Figure 28 This is a simulation result of the overall three-dimensional structure of the valve;

[0062] Figure 29 Figure 28 The result of a cross-section along the zx-axis plane of the overall structure;

[0063] Figure 30 This is a top view of valve embodiment 8 in this invention;

[0064] Figure 31 This is a cross-sectional view of the valve obtained along section line KK.

[0065] Figure 32 and Figure 33 The figures show the finite element simulation results of the valve in two open states.

[0066] Figure label:

[0067] Valve body 1, slit 2, diaphragm 3, piezoelectric material 4, upper electrode 5, lower electrode 6, recessed structure 7, piezoelectric actuation structure 8, opening 9. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0069] The following detailed description, in conjunction with the accompanying drawings, illustrates the technical solution of a unidirectional piezoelectric MEMS active valve and its application provided by various embodiments of the present invention.

[0070] Reference Figures 1 to 33 As shown, this embodiment of the invention provides a unidirectional piezoelectric MEMS active valve, including a non-piezoelectric actuation structure and at least one piezoelectric actuation structure 8; the non-piezoelectric actuation structure includes a valve body 1, or may also include other auxiliary structures other than the valve body 1, the valve body 1 serving as the outer frame of the valve to ensure structural stability; the piezoelectric actuation structure 8 is supported by the valve body 1, or by other auxiliary structures other than the valve body 1, and after the piezoelectric actuation structure 8 is fixed, its unsupported portion forms a movable piezoelectric actuation structure 8; the flow channel of the valve is composed of the piezoelectric actuation structure 8 and the non-piezoelectric actuation structure 8. A gap is formed between the actuating structural components, and the valve body 1 or auxiliary structure is designed with a recessed structure 7 to form the gap; when there are multiple piezoelectric actuating structural components 8, the gap between the piezoelectric actuating structural components 8 can also be formed; the average flow resistance of the valve flow channel formed by the gap in one direction is less than the average flow resistance in the opposite direction, so that the fluid presents a flow control effect in one direction in an average sense; the piezoelectric actuating structure contains at least 4 layers of piezoelectric material, and a voltage is applied to the piezoelectric actuating structural component 8 to make it displaced to control the opening and closing of the valve, thereby realizing the unidirectional opening and flow control of the valve for the fluid.

[0071] Specifically, the other auxiliary structures of the non-valve body 1 may or may not be present; when there are no auxiliary structures, the piezoelectric actuation structure 8 is fixed to the valve body 1; when there are auxiliary structures, the piezoelectric actuation structure 8 may be fixed to the auxiliary structure or fixed to the valve body 1. When it is fixed to the valve body 1, the non-piezoelectric actuation auxiliary structure has a recessed structure 7.

[0072] Specifically, the piezoelectric actuation structure 8 is fixed to the valve body 1 by peripheral support or fixed to other auxiliary structures other than the valve body 1 by intermediate support, forming actuation structure with different displacement forms.

[0073] Specifically, the number of other auxiliary structures used to support and fix the piezoelectric actuation structure 8 can be one or more. When there are multiple auxiliary structures, they are used to fix the piezoelectric actuation structure 8 respectively.

[0074] Specifically, the piezoelectric actuation structure 8 is one of the following shapes: conical, trapezoidal, rectangular, and fan-shaped.

[0075] Specifically, the piezoelectric actuation structure 8 has an upper electrode 5 and a lower electrode 6 made of metal material on the upper and lower surfaces of the piezoelectric material 4 layer. The surface of the upper electrode 5 or the lower electrode 6 is connected to a diaphragm 3 layer, and the diaphragm 3 layer is a non-active material, which makes the displacement of the piezoelectric actuation structure 8 greater.

[0076] Specifically, the multiple piezoelectric actuation structural members 8 can be arranged in parallel with fixed supports on the same side or on opposite sides, or in a combination of fixed supports on the same side and on opposite sides.

[0077] Specifically, the plurality of the piezoelectric actuation structures 8 may be distributed in a rotationally symmetrical manner, or in a left-right / up-down mirror arrangement.

[0078] Specifically, the flow resistance when the displacement direction of the piezoelectric actuation structure 8 is consistent with the direction of fluid flow is less than the flow resistance when the two directions are inconsistent. This makes the average flow resistance of the fluid flowing in the same direction less than the average flow resistance of the fluid flowing in the opposite direction. The valve can realize unidirectional opening and flow control of the fluid along the same direction.

[0079] Specifically, at least one piezoelectric actuation structure 8 has a first actuation structure subjected to a voltage to generate a displacement toward a first direction toward the flow channel, and adjacent actuation structures of this piezoelectric actuation structure 8 are displaced in the same direction as the first direction, or remain stationary, to ensure the unidirectionality of fluid flow.

[0080] Specifically, the piezoelectric actuation structure 8 is in a flat state when at rest, and the valve is normally closed. The displacement generated by each piezoelectric actuation structure 8 causes the valve to change from closed to open, allowing fluid to flow unidirectionally through the valve opening 9.

[0081] Specifically, after the piezoelectric actuation component 8 is displaced by the applied voltage, the displacement of the piezoelectric actuation component 8 can measure the size of the opening 9. Applying different voltages can control the size of the displacement, and the voltage can be controlled in a more precise manner. Therefore, the valve can achieve stepless adjustment of the size of the flow channel opening 9.

[0082] Specifically, the structural components that support and fix the piezoelectric actuation structure 8 are made of silicon, glass, or polymer materials and are formed through microfabrication techniques (such as etching and coating).

[0083] Specifically, the valve body 1 serves as the outer frame of the valve and works in conjunction with the piezoelectric actuation structure 8 to limit the size of the initial gap of the valve. It is necessary to maintain the internal sealing to prevent fluid leakage and ensure the reliability of the structure.

[0084] An application of a unidirectional piezoelectric MEMS active valve is available in electronic devices such as miniature heat sinks, bone conduction headphones, bone conduction glasses, wired headphones, wireless headphones, smartwatches, smart bracelets, AR glasses, VR glasses, and biomedical infusion pumps, or in other scenarios where perfect alternation between sealing and opening is desired.

[0085] Example 1:

[0086] This embodiment features a rectangular valve structure. The piezoelectric actuation component 8 is rectangular in shape and is a single component. It is fixed to the non-piezoelectric actuation auxiliary structure in the form of a central support. The inner wall of the outer frame of the valve body 1 has a recessed structure 7, namely a semi-circular groove. Figure 1 and Figure 2 The figures shown are schematic diagrams of valves in either the non-actuated or closed state. Figure 1 This is a top view of the valve. Figure 2 This is a cross-sectional view of the valve along section line AA. From both views, it can be observed that when the valve is closed, the piezoelectric actuation structure 8 is in a flat state. At this time, there is a small gap between the piezoelectric actuation structure 8 and the valve body 1, which can reach the micrometer (µm) level and is almost negligible. Therefore, the valve can be considered closed, and thus normally closed. Then, it can be seen from... Figure 2 The cross-sectional view provides a clearer view of the valve's layered structure. The piezoelectric actuation structure 8 consists of an upper electrode 5, four layers of piezoelectric material, a lower electrode 6, and three layers of diaphragm. These layers are deposited on the auxiliary structure to form a movable part. Applying voltage to the piezoelectric actuation structure 8 causes it to move.

[0087] Specifically, the valve body 1 and the auxiliary structure can be a substrate base wafer material with a back cavity formed using MEMS processes. For example, it can be a silicon wafer, quartz, or other suitable materials processed using MEMS processes. The piezoelectric actuation structure 8 can be composed of a diaphragm layer 3, a bottom electrode layer, a piezoelectric material layer 4, and a top electrode layer deposited on the auxiliary structure. Further, the diaphragm layer 3 of the piezoelectric actuation structure 8 can be relatively thin, for example, a thin layer on the order of approximately μm. In this respect, the diaphragm layer 3 material can be, but is not limited to, silicon, aluminum nitride, and oxides processed using MEMS technology. The bottom and top electrode layers can be suitable metallic materials, such as platinum (Pt), gold (Au), molybdenum (Mo), and other conductive materials, covering the upper and lower surfaces of the piezoelectric material layer 4, thereby allowing a voltage to be applied to generate deformation displacement. The piezoelectric material layer 4 can be a relatively thin piezoelectric film, for example, 0.5–5 μm, deposited and etched using MEMS technology. In this regard, the piezoelectric material layer 4 can be made of, but is not limited to, aluminum nitride (AlN), polyvinylidene fluoride (PVDF), lead zirconate titanate (PZT), any type of doped PZT (e.g., PMN-PT), etc. The coverage area of ​​the piezoelectric material 4 can be the entire diaphragm 3-layer structure, or it can be a part of the surface of the diaphragm 3-layer structure. In this embodiment, the piezoelectric material layer 4 covers most of the diaphragm 3-layer structure, but is not completely covered.

[0088] Specifically, a three-dimensional finite element simulation was performed on the valve in this embodiment to more clearly express the dynamic response state of the one-way valve when it is opened. For example... Figure 3 and Figure 4 The diagram shows the piezoelectric actuation structure 8 of the valve according to... Figure 3 Three-dimensional finite element simulation results of the cross-sectional view during motion. Figure 3 The results are the overall three-dimensional structural simulation of the valve. Figure 4The figures show the cross-sectional results along the zx-axis plane of the overall structure. From the two figures, it can be observed that the piezoelectric actuation structure 8 is integrally formed by the outer frame of the valve body 1. The piezoelectric actuation structure 8 is fixed by an auxiliary structure in the middle, and its bottom surface generally has a supporting surface. Therefore, the valve body 1 and the auxiliary structure are set as fixed constraints, and there is a small gap 2 between the piezoelectric actuation structure 8 and the valve body 1. Furthermore, there is an arc-shaped recessed structure 7 on the inner side of the valve body 1 at both free ends of the piezoelectric actuation structure 8. The range of this recessed structure 7 is along the entire edge of both sides of the valve body 1. This simulation result shows that when the applied voltage of the centrally fixed piezoelectric actuation structure 8 produces a downward displacement, the entire edge of the free ends of the piezoelectric actuation structure 8 can cooperate with the flow channel structure on the valve body 1, making the gap between the piezoelectric actuation structure 8 and the valve body 1 open to a large extent, forming an opening 9. At this point, since the displacement direction of the piezoelectric actuation component 8 is downward, assuming the fluid also flows downward, the average resistance of the fluid is small, allowing it to flow rapidly from top to bottom. If the fluid flows upward, a counterforce will form between the piezoelectric actuation component 8 and the fluid, resulting in a larger average flow resistance, and the fluid will affect the deformation direction of the piezoelectric actuation component. Therefore, the average resistance in the flow direction aligned with the displacement direction of the piezoelectric actuation component is less than the average resistance in the opposite direction, and the fluid flow direction does not affect the deformation direction of the piezoelectric actuation component. Thus, the valve can achieve unidirectional opening and flow control by aligning the fluid flow direction with the displacement direction of the piezoelectric actuation component. Furthermore, different bias voltages can be applied to the piezoelectric actuation component 8, resulting in varying degrees of valve opening. Applying voltage allows for precise control, enabling stepless adjustment of the valve opening 9.

[0089] Example 2:

[0090] In the previous embodiment, the piezoelectric actuation structure 8 was fixed by a non-piezoelectric actuation auxiliary structure, and could also be fixed by the valve body 1. In this embodiment, both ends of the piezoelectric actuation structure 8 are fixed to the outer frame of the valve body 1, forming a bridge-like piezoelectric actuation structure. Figure 5 , Figure 6 and Figure 7 The diagram shows a valve in a non-actuated or closed state. Figure 5 This is a top view of the valve. Figure 6 and Figure 7The figures show cross-sectional views of the valve along sections BB and CC, respectively. From these figures, it can be observed that when the valve is closed, the piezoelectric actuation structure 8 is in a flat state, and the valve body 1 has a recessed structure 7 on the inner side of the valve body 1 corresponding to the non-fixed edge of the piezoelectric actuation element. At this time, there is a small gap between the piezoelectric actuation structure 8 and the valve body 1, which can reach the micrometer (µm) level and is almost negligible. Therefore, the valve can be considered closed, and thus normally closed. Furthermore, the layered structure distribution of the valve can be observed more clearly from the cross-sectional views. The piezoelectric actuation structure 8 consists of an upper electrode 5, four layers of piezoelectric material, a lower electrode 6, and three layers of diaphragm. These layers are deposited on the periphery of the valve body 1 to form a movable piezoelectric MEMS component. Applying voltage to the piezoelectric actuation structure 8 causes it to displace.

[0091] Specifically, please refer to Figure 8 and Figure 9 Describe the valve's state when it is in the actuated / open position. Figure 8 and Figure 9 The results are from a three-dimensional finite element simulation when the valve is in the open state. Figure 8 The results are the overall three-dimensional structural simulation of the valve. Figure 9 Along the zy axis plane of the overall structure, i.e., along Figure 5 The result of cross-sectioning using the BB section line is illustrated. From Figure 8 and Figure 9 As can be observed, when voltage is applied to the piezoelectric actuator 8, the middle section of the bridge-type piezoelectric actuator vibrates downwards, changing the gap between the piezoelectric actuator 8 and the valve body 1. Since the valve body 1 has arc-shaped recesses 7 on its inner walls (excluding the fixed edge of the piezoelectric actuator), the piezoelectric actuator 8 engages with the valve body 1, causing the gap to gradually increase. An opening 9 is formed between the piezoelectric actuator 8, primarily in its middle displacement region, and the valve body 1, allowing fluid flow. Furthermore, since the piezoelectric actuator 8 is displaced downwards, assuming the fluid also flows downwards, the average resistance is lower, guiding the fluid to flow quickly from top to bottom. If the fluid flows upwards, a counterforce is formed between the piezoelectric actuator 8 and the fluid, resulting in higher average resistance and affecting the deformation direction of the piezoelectric actuator, making valve opening uncontrollable. Therefore, the average resistance in the flow direction aligned with the displacement direction of the piezoelectric actuation structure is less than the average resistance in the opposite direction, causing the fluid to tend to flow downwards. This results in unidirectional valve opening and flow control, meeting the unidirectional flow control requirements of the fluid. Furthermore, the size of the opening 9 can be adjusted by regulating the voltage. Simultaneously, the bridge-type piezoelectric actuation structure 8, fixed at both ends, offers greater reliability, ensuring structural stability.

[0092] Example 3:

[0093] Besides fixing the piezoelectric actuation component 8 to the valve body 1 with both ends fixed peripherally, it can also be fixed to the valve body 1 with one end fixed peripherally. This embodiment also uses a rectangular valve with a single piezoelectric actuation component 8, one end of which is fixed to the valve body 1, and the other end is free, thus forming a single cantilever valve structure. Figure 10 , Figure 11 and Figure 12 The diagram shows a valve in a non-actuated or closed state. Figure 10 This is a top view of the valve. Figure 11 and Figure 12 The figures show cross-sectional views of the valve along sections DD and EE, respectively. From these figures, it can be observed that when the valve is closed, the piezoelectric actuation structure 8 is in a flat state, and the valve body 1 has recessed structures 7 on all sides except the side where the piezoelectric actuation structure 8 is fixed. At this time, there is a small gap between the piezoelectric actuation structure 8 and the valve body 1, which can reach the micrometer (µm) level and is almost negligible. Therefore, the valve can be considered closed, and thus normally closed. Furthermore, it can be seen from... Figure 11 The cross-sectional view provides a clearer view of the valve's layered structure. The piezoelectric actuation structure 8 consists of an upper electrode 5, four layers of piezoelectric material, a lower electrode 6, and three layers of diaphragm. These layers are deposited on the periphery of the valve body 1 to form a movable piezoelectric MEMS component. Applying voltage to the piezoelectric actuation structure 8 causes it to move.

[0094] Specifically, please refer to Figure 13 and Figure 14 Describe the valve's state when it is in the actuated / open position. Figure 13 and Figure 14 The results are from a three-dimensional finite element simulation when the valve is in the open state. Figure 13 and Figure 14As can be observed, when voltage is applied to the piezoelectric actuation structure 8, the free end of the single cantilever beam piezoelectric actuation structure 8 begins to bend downwards. At this time, the gap between the free end of the piezoelectric actuation structure 8 and the valve body 1 will change. Since the valve body 1 has an arc-shaped recessed structure 7 on the inner sidewall except for the fixed edge of the piezoelectric drive element, the other three edges of the piezoelectric actuation structure 8 can cooperate with the valve body 1, causing the gap to gradually increase, forming an opening 9 between the free edge of the piezoelectric actuation structure 8 and the valve body 1. This method can achieve stepless control. In addition, since the piezoelectric actuation structure 8 is displaced downwards, the fluid will also tend to flow downwards towards the opening 9, consistent with the flow control in the previous embodiment. This same situation will not be elaborated further. Therefore, the valve, in conjunction with the downward flow pressure, allows for unidirectional flow, which can meet the unidirectional flow control requirements of the fluid. Furthermore, this structure has fewer components, mainly including a valve body 1 and the piezoelectric actuation structure 8, thus making it highly feasible. In terms of the structure of the valve body 1, in embodiment 1, only one side of the valve body 1 has a recessed structure 7, which cooperates with the opposite side of the valve body 1 of the fixed side of the piezoelectric actuation structure 8. In this embodiment, the other two non-fixed sides can also cooperate with the valve body 1, which can make the opening 9 of the valve larger when it is opened.

[0095] Example 4:

[0096] In the above example, there is one piezoelectric actuation component 8, but in practice, there can be multiple components to meet more diverse valve opening requirements 9. This example shows a one-way valve where multiple piezoelectric actuation components 8 are fixed to the valve body 1 to form a cantilever beam, and arranged in parallel in the same direction. For example... Figure 15 This is a schematic diagram of a valve in a non-actuated or closed state. Figure 15 This is a top view of the valve, and the cross-sectional view of the valve obtained along the section line FF is the same as the structure in Embodiment 2. Refer to the diagram in Embodiment 2 for explanation. As can be observed from the diagram, when the valve is in the closed state, the piezoelectric actuation structure 8 is in a flat state. At this time, there is a small gap between the piezoelectric actuation structure 8 and the valve body 1. Besides this piezoelectric actuation structure 8, the other two piezoelectric actuators also remain flat, and their gaps can reach the micrometer (µm) level, which is almost negligible. Therefore, the valve can be considered closed, and thus the valve is normally closed. Then, it can be seen from... Figure 8 The cross-sectional view provides a clearer view of the valve's layered structure. The piezoelectric actuation component 8 consists of an upper electrode 5, four layers of piezoelectric material, a lower electrode 6, and three layers of diaphragm. These layers are deposited on the periphery of the valve body 1 to form a piezoelectric MEMS movable part. Applying voltage to the piezoelectric actuation component 8 causes it to move. Furthermore, the voltage of each piezoelectric actuation component 8 can be controlled independently, providing high flexibility.

[0097] Furthermore, it can be referred to Figure 16 and Figure 17 Describe the valve's state when it is in the actuated / open position. Figure 16 and Figure 17 The results are finite element simulations of the valve in two open states. Figure 16 This diagram illustrates the opening state where multiple piezoelectric actuators 8 are subjected to voltage, all of which result in downward displacement. Figure 17 This diagram shows the open state where the first and third piezoelectric actuation structures 8 are displaced downwards by the applied voltage, while the second piezoelectric actuation structure 8 remains stationary. Figure 16 When a voltage is applied to the piezoelectric actuator 8 shown in the diagram, the free end of the single cantilever beam piezoelectric actuator 8 begins to bend downwards. At this time, the gap between the free end of the piezoelectric actuator 8 and the valve body 1 changes. Due to the arc-shaped recessed structure 7 on the inner sidewall of the valve body 1, the gap gradually increases, forming an opening 9 between the free end of the piezoelectric actuator 8 and the valve body 1. Simultaneously, if a smaller flow rate is desired, one or two piezoelectric actuators 8 can be kept stationary, i.e., de-energized. This allows the moving piezoelectric actuator 8 to form an opening 9 with the valve body 1, and the gap between the piezoelectric actuators 8 also increases, allowing fluid flow and causing the fluid to flow downwards in a unidirectional direction. Figure 17 In the middle, according to the actual flow requirements, the piezoelectric actuation structure 8 in the middle is de-energized and kept in a flat state. The fluid will also flow downwards and will not affect the direction of fluid flow. At this time, the gap between the piezoelectric actuation structure 8 will also form an opening 9. Figure 16 and Figure 17 These are two of the valve opening modes in this embodiment. The valve can also have other opening modes. Therefore, the combination of multiple piezoelectric actuation components 8 makes the valve adjustment methods more diverse and more flexible. Different movement modes will also affect the valve's opening direction for fluid flow, but the overall flow direction can still remain consistent, achieving the requirement of unidirectional control.

[0098] Example 5:

[0099] In the previous example, the three piezoelectric actuation structures 8 with peripheral fixed supports are fixed on the same side of the valve body 1. Of course, they can also be fixed in parallel with opposite fixed supports. Figure 18 , Figure 19 and Figure 20 This is the configuration of the piezoelectric actuation structure 8 when it is in the non-actuated / off state. Figure 18 This is a top view of the valve. Figure 19 and Figure 20 The following are cross-sectional views of the valve obtained along section lines GG and HH, respectively. Figure 18As can be seen, the two piezoelectric actuation components 8 are fixedly arranged on opposite sides, and the gap 2 between the piezoelectric actuation component 8 and the valve body 1 is divided into left and right sides. Figure 19 and Figure 20 The multi-layered structure of the valve can be seen more clearly in the image. Upper electrodes 5 and lower electrodes 6 are arranged on the upper and lower surfaces of the piezoelectric material 4. A voltage can be applied to the piezoelectric material 4, thereby causing the connected diaphragm 3 layer to vibrate. In practice, the piezoelectric material 4 can be distributed on a portion of the diaphragm 3 layer or on the entire surface of the diaphragm 3 layer. This example shows the case where the piezoelectric material 4 is distributed on a portion of the diaphragm 3 layer. Motion control can be achieved individually for each piezoelectric actuation component 8. Similarly, using the valve body 1 as the substrate material, a thin film layer is deposited to form a piezoelectric MEMS movable component.

[0100] Further references can be made. Figure 21 Describe in more detail the vibration pattern of the valve when it is in the vibrating / open state. Figure 21 This is a schematic diagram of the cross-section obtained along section line GG when the piezoelectric actuated structure 8 is in a vibrating state. Figure 21 In this process, applying a voltage to the actuating structure causes it to bend and vibrate downwards, forming an opening 9 with the recessed structure 7 on the right side of the valve body 1. Similarly, applying a voltage to another piezoelectric actuating structure 8 also produces a downward displacement, at which point the piezoelectric actuating structure 8 and the recessed structure 7 on the left side of the valve body 1 also form an opening 9. It is understandable that... Figure 21 This example illustrates a typical open state for the valve; however, valves can also be opened in other ways. For instance, when... Figure 21 When the medium-voltage electrically actuated structural component 8 bends downward to form an opening 9, Figure 21 The piezoelectric actuation structure 8 can remain stationary, and the opening 9 will be slightly smaller than when both piezoelectric actuation structures 8 are bent downwards. This arrangement of fixed supports on opposite sides also ensures that the gap between the piezoelectric actuation structures 8 is larger regardless of whether they are bent downwards. This embodiment differs from previous embodiments in that the peripheral fixed supports can be arranged not only along the same side but also separately along opposite sides, creating different opening methods for the unidirectional flow opening 9.

[0101] Example 6:

[0102] The multiple piezoelectric actuating components 8 can be arranged in parallel, symmetrically arranged horizontally / vertically, or rotationally symmetrically. The recessed structure 7 can be designed on the valve body 1, or it can be implemented by other non-piezoelectric actuating components. In this embodiment, a square-shaped one-way valve is constructed, consisting of multiple piezoelectric actuating components 8, a valve body 1, and a non-piezoelectric actuating component with a recessed structure 7. The piezoelectric actuating components 8 are fixed to the outer frame of the valve body 1 by peripheral supports, while a non-piezoelectric actuating component with an arc-shaped groove is located in the center of the valve. The composition and working principle of the valve can be described in more detail with reference to the above figures. Figure 22 and Figure 23 These are schematic diagrams of a valve in either an unactuated or closed state. Figure 22 This is a top view of the valve. Figure 23 This is a cross-sectional view of the valve along section line II. From both views, it can be observed that when the valve is closed, the piezoelectric actuation structure 8 is in a flat state. At this time, there is a small gap between the piezoelectric actuation structures 8, and between the piezoelectric actuation structure 8 and the non-piezoelectric actuation structure. According to MEMS fabrication technology, the gap can reach the micrometer (µm) level, which is almost negligible. Therefore, the valve can be considered closed, and thus the valve is normally closed. Furthermore, it can be seen from... Figure 23 The cross-sectional view provides a clearer view of the valve's layered structure. The piezoelectric actuation component 8 consists of an upper electrode 5, four layers of piezoelectric material, a lower electrode 6, and three layers of diaphragm. These layers are deposited around the valve body 1 to form a piezoelectric MEMS movable part. Applying voltage to the piezoelectric actuation component 8 causes it to displace. It is understandable that the voltage of each piezoelectric actuation component 8 can be controlled independently, offering high flexibility.

[0103] Specifically, further reference can be made. Figure 24 and Figure 25 Describe the valve's state when it is in the actuated / open position. Figure 24 and Figure 25 A three-dimensional finite element simulation structure of the valve in its open state. Figure 24 The results are the overall three-dimensional structural simulation of the valve. Figure 25The diagram shows the cross-sectional result along the zx-axis plane of the overall structure. As can be seen, when voltage is applied to the piezoelectric actuation component 8, the free end of the cantilever beam begins to bend downwards. At this time, the gap between the free end of each piezoelectric actuation component 8 and the non-piezoelectric actuated auxiliary component changes. Because the auxiliary structure has a concave arc structure 7, the gap gradually increases, forming an opening 9 between the free end of each piezoelectric actuation component 8 and the auxiliary structure. Simultaneously, if a reduced fluid flow rate is desired, one or more of the four piezoelectric actuation components 8 can be de-energized, remaining flat, thus reducing the overall opening 9. Since the moving part of the piezoelectric actuation element bends downwards, even if one of the piezoelectric actuation components is de-energized, the multiple piezoelectric actuation components 8 generally exhibit downward bending vibration, driving the fluid to flow downwards in a unidirectional direction. When one of the piezoelectric actuation components 8 is de-energized, an opening 9 is also formed between the flat and moving piezoelectric actuation components 8. The combination of multiple piezoelectric actuators 8 allows for more diverse valve adjustment methods and greater flexibility. Different movement methods will affect the fluid flow direction, but the overall flow direction can still be kept consistent, achieving the requirement of unidirectional control.

[0104] Example 7:

[0105] This example is another type of one-way valve. The valve is circular in shape, and multiple piezoelectric actuation components 8 are fixed to the auxiliary structure in the form of a central support. They are distributed in a rotationally symmetrical / left-right symmetrical manner. The valve body 1 has a concave structure 7, which is conical and can open the valve in conjunction with the displacement of the piezoelectric actuation components 8. Figure 26 and Figure 27 These are schematic diagrams of a valve in either an unactuated or closed state. Figure 26 This is a top view of the valve. Figure 27 The image shows a cross-sectional view of the valve along section line JJ. From the two images, it can be observed that when the valve is closed, the piezoelectric actuation structure 8 is in a flat state. The piezoelectric actuation element can be understood as a circular piezoelectric film fixed in the middle on an auxiliary structure, separated by gaps to form multiple piezoelectric actuation structures 8. At this time, there is a small gap between the piezoelectric actuation structures 8, and between the piezoelectric actuation structures 8 and the valve body 1. According to MEMS fabrication technology, the gap can reach the micrometer (µm) level, which is almost negligible. Therefore, the valve can be considered closed, and thus normally closed. Then, it can be seen from... Figure 27The cross-sectional view provides a clearer view of the valve's layered structure. The piezoelectric actuation component 8 consists of an upper electrode 5, four layers of piezoelectric material, a lower electrode 6, and three layers of diaphragm. These layers are deposited on the auxiliary structure to form a movable part. Applying voltage to the piezoelectric actuation component 8 causes it to displace. Unlike other embodiments, the recessed structure 7 in this valve body 1 is a conical structure. As the piezoelectric actuation component 8 moves downwards, the opening 9 continuously increases in size. Therefore, the recessed structure 7 can be adjusted according to actual processing conditions and can be designed into other different structures.

[0106] Specifically, please refer to Figure 28 and Figure 29 Further describe the valve's shape when it is in the actuated / open state. Figure 28 and Figure 29 A three-dimensional finite element simulation structure of the valve in its open state. Figure 28 The results are the overall three-dimensional structural simulation of the valve. Figure 29 The diagram shows the cross-sectional result along the zx-axis plane of the overall structure. As can be observed, when a voltage is applied to the piezoelectric actuation component 8, the free ends of all piezoelectric actuation components 8 bend downwards. At this time, the gap between the free end of each piezoelectric actuation component 8 and the valve body 1 changes. Due to the conical recessed structure 7 of the valve body 1, the gap gradually increases, forming an opening 9 between the free end of each piezoelectric actuation component 8 and the valve body 1. When all piezoelectric actuation components 8 are displaced downwards, they can all form an opening 9 with the recessed structure 7 of the valve body 1; therefore, the valve opening 9 is at its maximum at this time. It should be noted that when different voltage signals are applied to the piezoelectric material 4, such as applying a bias voltage, the valve stops at a certain position and remains open. In this case, the valve opening 9 depends on the magnitude of the voltage; the greater the voltage, the greater the displacement, and thus the larger the valve opening 9. From this perspective, when the magnitude of the bias voltage can be arbitrarily controlled, the valve can be adjusted more flexibly, and can be considered as stepless adjustment. In this embodiment, since the piezoelectric actuation structure 8 is fan-shaped, it can form a similar arc-shaped surface after downward displacement, making the flow surface smoother and promoting fluid flow. Therefore, the shape and structure of the piezoelectric actuation structure 8 can also affect the fluid flow to a certain extent. On the other hand, when the piezoelectric actuation elements can be individually controlled, different combinations of displacement forms, voltage polarity and magnitude allow the valve to achieve multi-stage and stepless adjustment of the valve opening 9. Therefore, the valve design of the present invention has high flexibility.

[0107] Example 8:

[0108] When a non-piezoelectric actuation structure is used to support a piezoelectric actuation structure 8, there can be multiple auxiliary structures, each supporting the piezoelectric actuation structure 8. In this embodiment, a rectangular valve structure is used. Two piezoelectric actuation structures 8 are fixed to the non-piezoelectric actuation auxiliary structure via a central support. The inner wall of the valve body 1's outer frame has a recessed structure 7, i.e., a near-arc-shaped groove. For example... Figure 30 and Figure 31 The figures shown are schematic diagrams of valves in either the non-actuated or closed state. Figure 30 This is a top view of the valve. Figure 31 This is a cross-sectional view of the valve obtained along section line KK. From Figure 30 As can be observed, the piezoelectric actuation components 8 are fixed by auxiliary structures. When the valve is closed, the piezoelectric actuation components 8 are in a flat state. At this time, there are small gaps between the piezoelectric actuation components 8 and between the piezoelectric actuation components 8 and the valve body 1. These gaps can reach the micrometer (µm) level and are almost negligible. Therefore, the valve can be considered closed, and thus the valve is normally closed. Then, it can be seen from... Figure 31 The cross-sectional view provides a clearer view of the valve's layered structure. The piezoelectric actuation structure 8 consists of an upper electrode 5, four layers of piezoelectric material, a lower electrode 6, and three layers of diaphragm. These layers are deposited on the auxiliary structure to form a movable component. Applying voltage to the piezoelectric actuation structure 8 causes it to displace. On the other hand, the valve body 1 and the auxiliary structure can be substrate wafers with back cavities formed using MEMS processes. For example, they can be suitable materials processed using MEMS processes, such as silicon wafers or quartz. The piezoelectric actuation structure 8 can be formed by depositing three layers of diaphragm, a bottom electrode layer, four layers of piezoelectric material, and a top electrode layer on the auxiliary structure. Furthermore, the three layers of diaphragm in the piezoelectric actuation structure 8 can be relatively thin, for example, approximately on the order of μm. Furthermore, the piezoelectric actuation structure 8, fixed in the middle, can be controlled by applying voltage to its two sides using separate piezoelectric materials 4.

[0109] Specifically, please refer to Figure 32 and Figure 33 Further describe the valve's configuration when it is in the actuated / open state, 32 and Figure 33 The results are finite element simulations of the valve in two open states. Figure 32When a voltage is applied to the piezoelectric actuator 8, both halves of each piezoelectric actuator 8 displace downwards. At this time, the gap between the free ends of the two halves of the piezoelectric actuator 8 and the valve body 1 changes. Because the inner sidewall of the valve body 1 has a concave arc structure 7, the gap gradually increases, forming an opening 9 between the two free ends of each piezoelectric actuator 8 and the valve body 1. The opening 9 of this valve opening is relatively large, but each piezoelectric actuator 8 needs to be energized. In practice, the degree of opening of the valve opening 9 can be adjusted according to the fluid flow requirements. Figure 33 The middle section shows another configuration of the valve open. The left lobe of the piezoelectric actuation component 8, corresponding to section line KK, and the right lobe of another piezoelectric actuation element, experience downward displacement after being energized, while the rest remain de-energized. In this configuration, fluid flows through both sides of the valve, but... Figure 32 The flow rate is reduced when the opening is open. Therefore, multiple piezoelectric actuation components 8 can achieve multi-level control of the opening 9. Figure 32 and Figure 33 The opening configuration can control the downward flow of fluid. The so-called unidirectional flow means that when the piezoelectric actuation structure 8 is displaced downward, the fluid will tend to flow downward towards the opening 9.

[0110] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A one-way piezoelectric MEMS active valve, characterized by, Includes a non-piezoelectric actuation structure and at least one piezoelectric actuation structure (8); The non-piezoelectric actuation structure includes a valve body (1), or may also include other auxiliary structures other than the valve body (1). The valve body (1) serves as the outer frame of the valve to ensure the stability requirements of the structure. The piezoelectric actuation structure (8) is supported by the valve body (1) or by other auxiliary structures other than the valve body (1). After the piezoelectric actuation structure (8) is fixed, its unsupported part forms a movable piezoelectric actuation structure (8). The flow channel of the valve is formed by the gap between the piezoelectric actuation structure (8) and the non-piezoelectric actuation structure. At this time, the valve body (1) or auxiliary structure is designed with a recessed structure (7) to form the gap. When there are multiple piezoelectric actuation structures (8), they can also be formed by the gap between the piezoelectric actuation structures (8). The valve flow channel formed by the gap has an average flow resistance in one direction that is less than the average flow resistance in the opposite direction, so that the fluid, on average, exhibits the effect of flow control in one direction. The piezoelectric actuation structure includes at least a layer of piezoelectric material (4). Different voltages are applied to the piezoelectric actuation structure (8) to cause it to generate displacement to control the opening and closing of the valve, thereby realizing the unidirectional opening of the valve to the fluid and flow control.

2. A one-way piezoelectric MEMS active valve according to claim 1, characterized in that: Other auxiliary structures other than the valve body (1) may or may not be present; When there is no auxiliary structure, the piezoelectric actuation structure (8) is fixed on the valve body (1); When there is an auxiliary structure, the piezoelectric actuation structure (8) can be fixed on the auxiliary structure or fixed on the valve body (1). When it is fixed on the valve body (1), the non-piezoelectric actuation auxiliary structure has a recessed structure (7).

3. The one-way piezoelectric MEMS active valve of claim 1, wherein: The piezoelectric actuation structure (8) is fixed to the valve body (1) by peripheral support or to other auxiliary structures other than the valve body (1) by intermediate support, forming actuation structures with different displacement forms.

4. The one-way piezoelectric MEMS active valve of claim 1, wherein: The number of other auxiliary structures used to support and fix the piezoelectric actuation structure (8) can be one or more. When there are multiple auxiliary structures, the piezoelectric actuation structure (8) is fixed separately.

5. The one-way piezoelectric MEMS active valve of claim 1, wherein: The piezoelectric actuation structure (8) is one of the following shapes: conical, trapezoidal, rectangular, or fan-shaped.

6. The one-way piezoelectric MEMS active valve of claim 1, wherein: The piezoelectric actuation structure (8) has an upper electrode (5) and a lower electrode (6) made of metal material on the upper and lower surfaces of the piezoelectric material (4) layer. The surface of the upper electrode (5) or the lower electrode (6) is connected to a diaphragm (3) layer, and the diaphragm (3) layer is an inactive material, which makes the displacement of the piezoelectric actuation structure (8) larger.

7. The one-way piezoelectric MEMS active valve of claim 1, wherein: Multiple piezoelectric actuation structural components (8) can be arranged in parallel with fixed supports on the same side or on opposite sides, or in a combination of fixed supports on the same side and on opposite sides.

8. The one-way piezoelectric MEMS active valve of claim 1, wherein: The multiple piezoelectric actuation structures (8) can be distributed in a rotationally symmetrical manner or in a left-right / up-down mirror arrangement.

9. The one-way piezoelectric MEMS active valve of claim 1, wherein: The flow resistance of the piezoelectric actuation structure (8) is less when the displacement direction is consistent with the direction of fluid flow than when the two directions are inconsistent. This makes the average flow resistance of the fluid flowing in the same direction less than the average flow resistance of the fluid flowing in the opposite direction. The valve can realize unidirectional opening and flow control of the fluid along the same direction.

10. The one-way piezoelectric MEMS active valve of claim 1, wherein: At least one piezoelectric actuation structure (8) wherein the first actuation structure is subjected to a voltage to produce a first direction displacement toward the flow channel, and the adjacent actuation structures of this piezoelectric actuation structure (8) are displaced in the same direction as the first direction or remain stationary to ensure the unidirectionality of fluid flow.

11. The one-way piezoelectric MEMS active valve of claim 1, wherein: The piezoelectric actuation structure (8) is in a flat state when at rest, and the valve is normally closed. The displacement generated by each piezoelectric actuation structure (8) causes the valve to change from closed to open, allowing fluid to flow unidirectionally through the valve opening (9).

12. The one-way piezoelectric MEMS active valve of claim 1, wherein: After the piezoelectric actuation component (8) is displaced by the applied voltage, the displacement of the piezoelectric actuation component (8) can measure the size of the opening (9). Applying different voltages can control the size of the displacement, and the voltage can be controlled more precisely. Therefore, the valve can achieve stepless adjustment of the size of the flow channel opening (9).

13. The one-way piezoelectric MEMS active valve of claim 1, wherein: The structural components that support and fix the piezoelectric actuation structure (8) are made of silicon, glass or polymer materials and are formed by microfabrication techniques (such as etching, coating).

14. The one-way piezoelectric MEMS active valve of claim 1, wherein: The valve body (1) serves as the outer frame of the valve and works in conjunction with the piezoelectric actuation structure (8) to limit the size of the initial gap of the valve. It is necessary to maintain the internal sealing to prevent fluid leakage and ensure the reliability of the structure.

15. The use of a one-way piezoelectric MEMS active valve according to any one of claims 1-14, characterized in that: It can be applied to electronic devices such as miniature heat sinks, bone conduction headphones, bone conduction glasses, wired headphones, wireless headphones, smartwatches, smart bracelets, AR glasses, VR glasses, and biomedical infusion pumps, or other scenarios where a perfect balance between sealing and open operation is desired.

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