Active valve based on middle clamped piezoelectric film and application of active valve
By using a centrally fixed piezoelectric diaphragm active valve design, the shortcomings of traditional valves in terms of miniaturization and rapid response are solved, achieving fast, low-energy, and highly flexible fluid or acoustic control, suitable for modern portable devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- IMOVE INTELLIGENT TECHNOLOGIES (DONGGUAN) CO LTD
- Filing Date
- 2024-12-26
- Publication Date
- 2026-04-17
AI Technical Summary
Traditional valve designs suffer from problems such as large size, slow response speed, high complexity, high energy consumption, and low flexibility, making it difficult to adapt to the miniaturization and rapid response requirements of modern portable devices.
An active valve design based on a centrally fixed piezoelectric film is adopted. The piezoelectric actuation structure is used to achieve rapid switching and fluid or acoustic control through voltage control, reducing mechanical parts and adopting non-contact action to improve reliability and energy efficiency.
It achieves fast response, low energy consumption, precise control and high flexibility of fluid or acoustic wave control, and is suitable for miniaturized electronic devices, reducing the risk of failure and improving equipment reliability.
Smart Images
Figure CN121876216A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fluid control technology, and particularly relates to an active valve based on a centrally fixed piezoelectric film 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) have excellent piezoelectric properties and are widely used in industry. Piezoelectric thin films are prepared by fabricating piezoelectric materials into thin films (at a very low density), often deposited on substrates such as silicon and glass. This technology enables efficient energy conversion of the piezoelectric effect at a microscale, making it an ideal driving method in micro-devices.
[0004] Piezoelectric thin films have the following advantages: fast response, piezoelectric materials can quickly deform under the action of an electric field, enabling rapid control; low energy consumption, as they can maintain their deformed state without continuous power supply, resulting in low energy consumption; high precision, as the deformation of piezoelectric materials can be finely adjusted by precisely controlling the voltage; and miniaturization, making them suitable for integration into microdevices to meet the needs of microfluidic systems.
[0005] However, in the existing technology, there are still some challenges in how to effectively use piezoelectric films in practical valve applications, such as the integration process of the film, the optimization of the driving voltage, and how to improve the deformation transmission efficiency.
[0006] Problems with existing solutions:
[0007] ① Size and weight: Traditional valve designs generally have large mechanical components, which increases the overall size and weight of the equipment. This makes them unsuitable for the miniaturization requirements of modern portable devices and prevents their application in small electronic mobile devices such as headphones and mobile phones.
[0008] ② 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 and has a phase lag with the valve, which affects the performance of the equipment.
[0009] ③ Complexity and reliability: Complex mechanical design increases the risk of failure and maintenance costs. Furthermore, passive valves are only suitable for low-frequency opening and closing. Under high-frequency operation, the valves have a shorter service life and their reliability is insufficient for high-speed use.
[0010] ④Low flexibility: The fixed structure of passive valves makes it impossible to dynamically adjust the flow of microfluidics according to needs, making it difficult to achieve precise control of fluid or sound wave flow.
[0011] ⑤ 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.
[0012] The following problems still exist:
[0013] Traditional valve design: Mechanical valves used to control fluid flow or sound waves typically rely on complex mechanical structures and components, such as springs and pistons, for operation.
[0014] (a) Passive and static seals: Fixed seals are used to block or allow fluid flow, such as closed cantilever passive valves, ball valves, umbrella valves, etc. They achieve unidirectional flow control of fluid through the interaction between the special arrangement of the valve and the direction of fluid flow.
[0015] (ii) 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.
[0016] Therefore, a novel active valve design based on piezoelectric films is particularly important in order to overcome the shortcomings of traditional technologies and provide a more efficient fluid control solution. Summary of the Invention
[0017] This invention provides an active valve based on a centrally fixed piezoelectric thin film and its application, in order to solve the problems in the prior art.
[0018] The present invention adopts the following technical solution: an active valve based on a centrally fixed piezoelectric film, comprising a non-piezoelectric actuation structure and at least one piezoelectric actuation structure;
[0019] The non-piezoelectric actuation structure includes an outer frame and a supporting component. The outer frame forms the overall frame of the valve, and the supporting component is used to support and fix the piezoelectric actuation structure. The piezoelectric actuation structure is used to control the formation of airflow / liquid flow channels to control the opening and closing of the valve.
[0020] A gap is provided between the piezoelectric actuation structure and the outer frame of the non-piezoelectric actuation structure, or between the piezoelectric actuation structures when there are multiple piezoelectric actuation structures, or simultaneously between the piezoelectric actuation structure and the outer frame and between the piezoelectric actuation structures. When the gap is opened, an airflow / liquid flow channel is formed.
[0021] The piezoelectric actuation structure is fixed to the support component in the form of an intermediate fixed support; the piezoelectric actuation structure contains at least a piezoelectric material, and different voltages are applied to the piezoelectric actuation structure to cause the actuation structure to move, thereby controlling the opening and closing of the valve.
[0022] Furthermore, the piezoelectric actuation structure is one of the following shapes: conical, trapezoidal, rectangular, or fan-shaped.
[0023] Furthermore, the number of the supporting components is one or more.
[0024] Furthermore, the plurality of piezoelectric actuation structures can be distributed in a spiral shape, or in a mirror-image arrangement (left-right / up-down).
[0025] Furthermore, the piezoelectric actuation structure has an upper electrode and a lower electrode made of metal material on both the top and bottom of the piezoelectric material. 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.
[0026] Furthermore, each of the piezoelectric actuation structures is divided into two halves, one of which is subjected to voltage to generate displacement in a first direction, and the other half is displaced in the opposite or the same direction as the first direction, which can be controlled separately.
[0027] Furthermore, the valve is in a normally closed or normally open state, and the displacement generated by each piezoelectric actuation component causes the valve to change to an open or closed state, allowing or hindering fluid flow through the position controlled by the valve.
[0028] Furthermore, the inner wall of the outer frame adjacent to each free end of the piezoelectric actuation structure is a conventional vertical plane or has a recessed structure.
[0029] Furthermore, the recessed structure on the inner sidewall of the outer frame allows the valve to be immediately in an open or closed state after the piezoelectric actuation component is displaced by the applied voltage. The degree of opening can be measured based on the degree of displacement of the piezoelectric actuation component, thus enabling stepless valve control.
[0030] Furthermore, the recessed structure on the inner sidewall of the outer frame, in conjunction with the displacement of the piezoelectric actuation structure, can achieve unidirectional or bidirectional flow control of the valve. Unidirectional flow control allows the fluid to flow in only one direction, while bidirectional flow control allows the fluid to flow in one direction while achieving directional adjustability.
[0031] Furthermore, the support components are typically made of silicon, glass, or polymer materials.
[0032] An active valve based on a centrally fixed piezoelectric film is 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 applications where perfect alternation between sealing and opening is desired.
[0033] The above-described at least one technical solution adopted in the embodiments of the present invention can achieve the following beneficial effects:
[0034] 1. Dynamic control is possible. The piezoelectric film material enables the valve to respond quickly to voltage changes, achieving precise fluid or acoustic control.
[0035] 2. Suitable for miniaturized electronic devices, the design of microelectromechanical systems (MEMS) is well-suited to the miniaturization needs of modern portable devices.
[0036] 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.
[0037] 4. High energy efficiency: Using piezoelectric materials as piezoelectric actuation structural components can reduce energy consumption, achieve efficient valve operation, and alleviate the high load requirements brought about by the high performance of modern electronic devices.
[0038] 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
[0039] 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:
[0040] Figure 1 The diagram shows the structure of a square, centrally fixed-support type valve in either a non-vibration or closed state.
[0041] Figure 2 for Figure 1 A cross-sectional view along section line AA when the valve is closed;
[0042] Figure 3 for Figure 1 A cross-sectional view along section line AA when the valve is open;
[0043] Figure 4 for Figure 1 A cross-sectional view along section line BB when the middle valve is open;
[0044] Figure 4a The diagram shows the piezoelectric actuation structure of the valve according to... Figure 3 and Figure 4 A 3D finite element simulation result of the cross-sectional view during motion;
[0045] Figure 5 The diagram shows the structure of a hexagonal, centrally fixed-support type valve in either a non-vibration or closed state.
[0046] Figure 6 for Figure 5 A cross-sectional view along the CC section line when the valve is closed;
[0047] Figure 7 for Figure 5 A cross-sectional view along the CC section line when the valve is open;
[0048] Figure 8 The diagram shows the structure of a circular, centrally fixed-support valve in either a non-vibration or closed state.
[0049] Figure 9 for Figure 8 A cross-sectional view along the DD section line when the valve is closed;
[0050] Figure 10 for Figure 8 A cross-sectional view along the DD section line when the middle valve is open;
[0051] Figure 11 A schematic diagram of a valve in its non-actuated state is shown.
[0052] Figure 12 for Figure 11 A cross-sectional view along the EE section line when the valve is closed;
[0053] Figure 13 for Figure 11 A cross-sectional view along the EE section line when the valve is open;
[0054] Figure 14 A bottom view showing the valve in its closed state is displayed;
[0055] Figure 15for Figure 14 A cross-sectional view along section line FF when the valve is closed;
[0056] Figure 16 for Figure 14 A cross-sectional view along section line FF when the valve is open;
[0057] Figure 17 for Figure 14 A cross-sectional view along the GG section line when the valve is open;
[0058] Figure 18 A bottom view of the valve is shown in its unactuated / energized state;
[0059] Figure 19 for Figure 18 A cross-sectional view along the HH section line when the valve is closed;
[0060] Figure 20 for Figure 18 The middle view is a cross-sectional view along the HH section line when the piezoelectric actuator is in a vibrating or closed state.
[0061] Figure 21 A bottom view of the valve in the non-actuated / closed state is shown;
[0062] Figure 22 for Figure 21 A sectional view along section line II;
[0063] Figure 23 for Figure 21 A cross-sectional view along line II when the medium-voltage electric actuator is in the downward open / closed state;
[0064] Figure 24 for Figure 21 A cross-sectional view along line II when the medium-voltage electric actuator is in the upward open / closed state;
[0065] Figure label:
[0066] 1. Outer frame; 2. Gap; 3. Intermediate support; 4. Piezoelectric material; 5. Upper electrode; 6. Lower electrode; 7. Opening. Detailed Implementation
[0067] 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. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0068] The following detailed description, in conjunction with the accompanying drawings, illustrates the technical solution of an active valve based on a centrally fixed piezoelectric thin film and its application, according to various embodiments of the present invention.
[0069] Reference Figures 1 to 24 As shown, an embodiment of the present invention provides an active valve based on a centrally fixed piezoelectric film, including a non-piezoelectric actuation structure and at least one piezoelectric actuation structure;
[0070] The non-piezoelectric actuation structure includes an outer frame and a supporting component. The outer frame forms the overall frame of the valve, and the supporting component is used to support and fix the piezoelectric actuation structure. The piezoelectric actuation structure is used to control the formation of airflow / liquid flow channels to control the opening and closing of the valve.
[0071] A gap is provided between the piezoelectric actuation structure and the outer frame of the non-piezoelectric actuation structure, or between the piezoelectric actuation structures when there are multiple piezoelectric actuation structures, or simultaneously between the piezoelectric actuation structure and the outer frame and between the piezoelectric actuation structures. When the gap is opened, an airflow / liquid flow channel is formed.
[0072] The piezoelectric actuation structure is fixed to the support component in the form of an intermediate fixed support; the piezoelectric actuation structure contains at least a piezoelectric material, and different voltages are applied to the piezoelectric actuation structure to cause the actuation structure to move, thereby controlling the opening and closing of the valve.
[0073] Specifically, the piezoelectric actuation structure is one of the following shapes: conical, trapezoidal, rectangular, or fan-shaped.
[0074] Specifically, the number of the supporting components is one or more, which can support multiple piezoelectric actuation structural components respectively.
[0075] Specifically, the piezoelectric actuation structure can be distributed in a spiral shape, or in a mirror-image arrangement on the left and right or up and down.
[0076] Specifically, the piezoelectric material 4 of the piezoelectric actuation structure has an upper electrode 5 and a lower electrode 6 made of a metal material on both the top and bottom. The surface of the upper electrode 5 or the lower electrode 6 is connected to a diaphragm layer, and the diaphragm layer is a non-active material, which makes the displacement of the piezoelectric actuation structure larger.
[0077] Specifically, each of the piezoelectric actuation structures is divided into two halves, one of which is subjected to voltage to generate displacement in a first direction, and the other half is displaced in the opposite or the same direction as the first direction, which can be controlled separately.
[0078] Specifically, the valve is in a normally closed or normally open state, and the displacement generated by each piezoelectric actuation component causes the valve to change to an open or closed state, allowing or hindering fluid flow through the position controlled by the valve.
[0079] Specifically, the inner wall of the outer frame adjacent to each free end of the piezoelectric actuation structure is a conventional vertical plane or has a recessed structure.
[0080] Specifically, the recessed structure on the inner sidewall of the outer frame allows the valve to be immediately in an open or closed state after the piezoelectric actuation component is displaced by the applied voltage. The degree of the opening 7 can be measured according to the degree of displacement of the piezoelectric actuation component, thus enabling stepless control of the valve.
[0081] Specifically, the recessed structure on the inner sidewall of the outer frame, in conjunction with the displacement of the piezoelectric actuation structure, can achieve unidirectional or bidirectional flow control of the valve. Unidirectional flow control allows the fluid to flow in only one direction, while bidirectional flow control allows the fluid to flow in one direction while maintaining directional adjustability to adapt to more application scenarios.
[0082] Specifically, the support component is typically made of silicon, glass, or polymer materials; it is formed by microfabrication techniques (such as etching or coating), and piezoelectric material 4 is deposited on the support component to form a movable component.
[0083] The outer frame refers to the structure of the valve, which ensures that the fluid can flow in a predetermined direction when passing through it. The flow rate or pressure is adjusted by controlling the relative positions of the components of the outer frame. It provides a passage for the fluid to pass through the outer frame and maintains the internal sealing to prevent fluid leakage.
[0084] It should be noted that the microstructure design of the outer frame minimizes complex mechanical parts and employs a simple precision manufacturing process to ensure that the outer frame maintains high sealing performance and durability while achieving miniaturization.
[0085] An active valve based on a centrally fixed piezoelectric film is 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 applications where perfect alternation between sealing and opening is desired.
[0086] Normally closed type:
[0087] Example 1: Square + double central supports 3 + vertical outer frame 1:
[0088] Figure 1The diagram illustrates a square, centrally fixed-support valve structure in either a non-vibrating or closed state. As shown, the valve structure comprises two centrally fixed-support piezoelectric actuation components, each divided into two halves, primarily driven by a piezoelectric film. These two piezoelectric actuation components can achieve different movement states to form an opening 7 as needed. The diagram shows the valve in its closed state. It should be noted that in this state, the two centrally fixed-support piezoelectric actuation components are considered essentially flat, in a non-energized / undeformed state, and both are in the same plane, resulting in a tiny gap in the valve, reaching the micrometer (µm) level. This gap can be considered the valve in a closed state, therefore the valve is normally closed. In other aspects, each piezoelectric actuation component consists of a diaphragm layer and piezoelectric material 4. The diaphragm covers the centrally fixed support element 3 and forms a free end through various gaps. The gap between the diaphragm and the outer frame is formed by the outer frame, the cantilever side of the diaphragm, and the support components. Then, the respective piezoelectric materials 4 are applied over the diaphragm to drive the free end of the diaphragm to move vertically. Furthermore, it is understandable that the piezoelectric actuation components are tapered in shape and should be as uniform in size as possible to ensure consistent vibration characteristics. Each piezoelectric actuation component can be individually controlled by applying voltage to a piezoelectric film, allowing one to open, another to close, or both to shift in opposite directions to form a larger opening, depending on the fluid flow control requirements. From this perspective, the valve allows for active control of the fluid flow; for example, applying voltage can open one or more of the piezoelectric actuation components, and once the voltage is removed, the components return to a closed or stationary state.
[0089] Specifically, each piezoelectric actuation structure includes a diaphragm layer material and a piezoelectric layer material. When a voltage is applied to the piezoelectric layer material, it drives the free end of the supporting component to displace. For example, the diaphragm layer can be single-crystal silicon formed into a cantilever beam shape using MEMS technology, or other suitable materials such as oxides. The piezoelectric material 4 can be a piezoelectric thin film layer formed on a portion of the diaphragm layer using MEMS technology. Alternatively, when the piezoelectric material 4 is applied to the diaphragm, it can cover the entire arm or only a portion of it. For example, the piezoelectric material 4 may only cover the side near the fixed end of the arm and extend to the side near the free end of the arm, covering only a portion of the cantilever beam area. In this case, when a voltage is applied to the piezoelectric material 4, the piezoelectric material 4 will deform, thereby causing the diaphragm to displace as well.
[0090] For specific details, please refer to Figure 2 The structure of each piezoelectric actuation structural layer is described in more detail. Figure 2 for Figure 1 A schematic diagram of the cross-section along section line AA. From Figure 2As can be seen, a tiny gap can be formed between the outer frame and the arm. In this respect, the valve outer frame 1 and the supporting component can be substrate base material with a back cavity formed using MEMS technology. For example, it can be a silicon wafer, quartz, or other suitable material processed using MEMS technology. The piezoelectric actuation structure can be composed of a diaphragm layer, a bottom electrode layer, a piezoelectric material 4, and a top electrode layer deposited on the substrate material of the intermediate support 3. On the other hand, the diaphragm layer of the piezoelectric actuation structure can be a relatively thin layer with a certain high Young's modulus, and a suitable material can be selected according to the actual working requirements of the valve, for example, a thin layer on the order of approximately μm. In this respect, the diaphragm layer material can be processed using MEMS technology, but is not limited to silicon, aluminum nitride, and oxides. The bottom and top electrode layers can be suitable metallic materials, such as conductive materials like platinum (Pt), gold (Au), and molybdenum (Mo), covering the upper and lower surfaces of the piezoelectric material 4, thereby allowing a voltage to be applied to generate deformation displacement. In some respects, the piezoelectric material 4 can be a relatively thin (e.g., 0.5–5 μm) piezoelectric film deposited and etched using MEMS processing techniques. In this respect, the piezoelectric material 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.
[0091] For specific details, please refer to Figures 3-4 A more detailed description of the vibration pattern of the piezoelectric actuator structure when the valve is in the vibrating / open state. Figure 3 and Figure 4 These are schematic cross-sectional views along sections AA and BB, respectively, showing the piezoelectric actuated structure in a vibrating or open state. It is understood that... Figures 3-4 This is a typical example of the valve being in the open state; the valve can also be in other open states. Figure 3 In this process, a voltage is applied to the piezoelectric films of the two pairs of intermediate fixed piezoelectric actuation structures 3, causing them to displace in opposite directions. At this time, the opening 7 formed by the gap 2 between the piezoelectric actuation structure and the outer frame is not very large. However, due to the displacement in opposite directions, the gap 2 between the piezoelectric actuation structures forms a larger opening 7, allowing fluid flow. The principle of this open state is that... Figure 3 When a voltage is applied to the piezoelectric film, the piezoelectric actuation structure vibrates upwards in a bending motion. If the other piezoelectric actuation structure is closed, opening 7 includes a slight opening in the gap between the piezoelectric actuation structure and the outer frame, as well as a side opening in the gap between the piezoelectric actuation structures. However, if a voltage is also applied to the piezoelectric film of the other piezoelectric actuation structure at the same time, driving it to bend downwards, then the degree of opening of the gap between the piezoelectric actuation structures will be significantly increased.
[0092] 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 valve when it is opened. For example... Figure 4a The diagram shows the piezoelectric actuation structure of the valve according to... Figure 3 and Figure 4 The results of a three-dimensional finite element simulation of the cross-sectional view during motion are shown in the figure. As can be observed, the piezoelectric actuation structure is fixed by the central support component 3, and its bottom surface generally has a support surface, so the support component 3 is stationary. Each piezoelectric actuation component is separated by gaps, allowing different voltage signals to be applied to displace the actuation components in different directions. Furthermore, the outer frame 1 serves as the overall valve frame, enclosing the piezoelectric actuation components, and gaps are left between the outer frame 1 and each piezoelectric actuation component, allowing the piezoelectric actuation components to swing up and down with their free ends. This simulation result shows that when the displacement directions of adjacent piezoelectric actuation components are opposite, the valve opening 7 can be larger, and the gaps between each component can form openings 7. This reduces the resistance of the fluid passing through the valve opening, increasing the flow rate. Simultaneously, the valve is symmetrical left-right and up-down, allowing the fluid to flow more evenly through the valve and reducing stress concentration.
[0093] Example 2: Hexagonal + three intermediate fixed support type + arc-shaped groove valve 1:
[0094] Figure 5 The figure illustrates a hexagonal, centrally fixed-support valve structure in a non-vibrational or closed state. As shown, the valve structure includes three centrally fixed-support piezoelectric actuation components, each divided into two halves, primarily driven by a piezoelectric film. These two piezoelectric actuation components can form openings 7 according to different movement states as needed. Unlike Embodiment 1, the valve frame 1 has a recessed arc structure, which, in conjunction with the actuating components, better forms the openings 7. Figure 5The diagram shows the valve in its closed state. It should be noted that at this point, the three intermediate fixed-support piezoelectric actuation components are considered to be essentially flat, in a non-energized / undeformed state, and on the same plane, resulting in only a tiny gap in the valve, which can reach the micrometer (µm) level. Therefore, the valve can be considered closed at this time. In other aspects, each piezoelectric actuation component consists of a diaphragm layer and piezoelectric material 4. The diaphragm covers the intermediate fixed-support element 3 and forms a free end through various gaps. The gap between the diaphragm and the outer frame is formed by the outer frame and the cantilever side of the diaphragm, and the supporting components. Then, the respective piezoelectric material 4 covers the diaphragm, thereby driving the free end of the diaphragm to produce vertical displacement. Furthermore, it is understood that the piezoelectric actuation components are tapered and should be as uniform in size as possible to ensure consistent vibration characteristics. Each piezoelectric actuation component can be individually controlled by applying voltage to the piezoelectric film, allowing for vertical displacement, depending on the fluid flow control requirements. From this perspective, valves enable active control of the degree of fluid flow. For example, applying voltage can be used to open one or more of each piezoelectric actuator, and once the applied voltage is stopped, the piezoelectric actuator will return to a closed or stationary state.
[0095] Specifically, each piezoelectric actuation structure includes a diaphragm layer material and a piezoelectric layer material. When a voltage is applied to the piezoelectric layer material, it drives the free end of the supporting component to displace. For example, the diaphragm layer can be single-crystal silicon formed into a cantilever beam shape using MEMS technology, or other suitable materials such as oxides. The piezoelectric material 4 can be a piezoelectric thin film layer formed on a portion of the diaphragm layer using MEMS technology. Alternatively, when the piezoelectric material 4 is applied to the diaphragm, it can cover the entire arm or only a portion of it. For example, the piezoelectric material 4 may only cover the side near the fixed end of the arm and extend to the side near the free end of the arm, covering only a portion of the cantilever beam area. In this case, when a voltage is applied to the piezoelectric material 4, the piezoelectric material 4 will deform, thereby causing the diaphragm to displace as well.
[0096] For specific details, please refer to Figure 6 The structure of each cantilever beam piezoelectric actuation structural component layer is described in more detail. Figure 6 for Figure 5 A schematic diagram of the cross-section along section line CC. From Figure 6It can be seen that a tiny gap can be formed between the outer frame and the arm. In this respect, the outer frame and the intermediate fixed support 3 can be substrate base circle materials with back cavities formed using MEMS technology. For example, they can be suitable materials processed using MEMS technology, such as silicon wafers or quartz. Considering the processing conditions, the outer frame can also be other machined components such as metal shells. The piezoelectric actuation structure can be composed of a diaphragm layer, a bottom electrode layer, a piezoelectric material 4, and a top electrode layer deposited on the substrate material of the intermediate fixed support 3. On the other hand, the diaphragm layer of the piezoelectric actuation structure can be a relatively thin layer with a certain high Young's modulus, and a suitable material can be selected according to the actual working requirements of the valve, such as a thin layer on the order of approximately μm. In this respect, the diaphragm layer material can be processed using MEMS technology, but is not limited to silicon, aluminum nitride, and oxides. The bottom and top electrode layers can be suitable metallic materials, such as conductive materials like platinum (Pt), gold (Au), and molybdenum (Mo), covering the upper and lower surfaces of the piezoelectric material 4, thereby allowing a voltage to be applied to generate deformation displacement. In some respects, the piezoelectric material 4 can be a relatively thin (e.g., 0.5–5 μm) piezoelectric film deposited and etched using MEMS processing techniques. In this respect, the piezoelectric material 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.
[0097] For specific details, please refer to Figure 7 A more detailed description of the vibration pattern of the piezoelectric actuator structure when the valve is in the vibrating / open state. Figure 7 This is a schematic cross-sectional view along section line CC when the piezoelectric actuated structure is in a vibrating or open state. It can be understood that... Figure 7 This is a typical example of the valve being in the open state; the valve can also be in other open states. Figure 7 In this process, a voltage is applied to the piezoelectric films of the three intermediate fixed supports 3 piezoelectric actuation structures, causing them to displace in the same direction. This, combined with the concave arc structure of the outer frame, creates an opening 7 that allows fluid flow. The principle behind this open state is that... Figure 7 When a voltage is applied to the piezoelectric film, the piezoelectric actuation structure vibrates downwards in a bending motion. During this downward vibration, the gap between the outer frame and the piezoelectric actuation structure gradually increases, forming opening 7. It is understood that a concave arc structure exists on the entire inner side of the valve outer frame 1, creating a gap between this structure and the free end of each supporting component, thus allowing the valve to open to a large extent. Furthermore, since the opening 7 between the outer frame and the piezoelectric actuation structure opens immediately and gradually increases during the displacement of the piezoelectric actuation structure, this control is stepless, fulfilling the performance requirement of actively controlling the outer frame for stepless adjustment.
[0098] Example 3: Circular + Four Intermediate Fixed Supports Type:
[0099] Figure 8 The diagram illustrates a circular, centrally fixed-support valve structure in a non-vibrating or closed state. As shown, the valve structure includes four centrally fixed-support piezoelectric actuation components, each divided into two fan-shaped segments. Unlike Embodiment 2, this valve's outer frame 1 has a conical structure, simplifying fabrication and allowing for better formation of the opening 7 in conjunction with the actuating element. Figure 8 The diagram shows the valve in its closed state. It should be noted that at this point, the four intermediate fixed-support piezoelectric actuation components are considered essentially flat, lying in the same plane, and in a state of no energization / no deformation. This results in a valve with only a tiny gap, which can reach the micrometer (µm) level. Therefore, the valve can be considered closed at this time. In other aspects, each piezoelectric actuation component consists of a diaphragm layer and piezoelectric material 4. The diaphragm covers the intermediate fixed-support element 3 and forms a free end through various gaps. The gap between the diaphragm and the outer frame is formed by the outer frame and the cantilever side of the diaphragm, and the supporting components. Then, the respective piezoelectric material 4 covers the diaphragm, thereby driving the free end of the diaphragm to produce vertical displacement. Each piezoelectric actuation component can be individually controlled by applying voltage to the piezoelectric film, allowing for vertical displacement, depending on the fluid flow control requirements.
[0100] Specifically, each piezoelectric actuation structure includes a diaphragm layer material and a piezoelectric layer material. When a voltage is applied to the piezoelectric layer material, it drives the free end of the supporting component to displace. For example, the diaphragm layer can be single-crystal silicon formed into a cantilever beam shape using MEMS technology, or other suitable materials such as oxides. The piezoelectric material 4 can be a piezoelectric thin film layer formed on a portion of the diaphragm layer using MEMS technology. Alternatively, when the piezoelectric material 4 is applied to the diaphragm, it can cover the entire arm or only a portion of it. For example, the piezoelectric material 4 may only cover the side near the fixed end of the arm and extend to the side near the free end of the arm, covering only a portion of the cantilever beam area. In this case, when a voltage is applied to the piezoelectric material 4, the piezoelectric material 4 will deform, thereby causing the diaphragm to displace as well.
[0101] For specific details, please refer to Figure 9 The structure of each cantilever beam piezoelectric actuation structural component layer is described in more detail. Figure 9 for Figure 8 A schematic diagram of the cross-section along section line DD. From Figure 9It can be seen that the gap between the outer frame and the arm can form a tiny gap. In this respect, the outer frame and the intermediate fixed support 3 can be substrate base material with a back cavity formed using MEMS technology. For example, it can be a silicon wafer, quartz, or other suitable material processed using MEMS technology. The piezoelectric actuation structure can be composed of a diaphragm layer, a bottom electrode layer, a piezoelectric material 4, and a top electrode layer deposited on the substrate material of the intermediate fixed support 3. On the other hand, the diaphragm layer of the piezoelectric actuation structure can be relatively thin, for example, a thin layer of about μm, and a suitable material can be selected according to the actual working requirements of the valve. In this respect, the diaphragm layer material can be processed using MEMS technology, but is not limited to silicon, aluminum nitride, and oxides. The bottom and top electrode layers can be suitable metallic materials, such as conductive materials like platinum (Pt), gold (Au), and molybdenum (Mo), covering the upper and lower surfaces of the piezoelectric material 4, thereby allowing a voltage to be applied to generate deformation displacement. In some aspects, the piezoelectric material 4 can be a relatively thin (e.g., 0.5–5 μm) piezoelectric film deposited and etched using MEMS technology. In this regard, the piezoelectric material 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).
[0102] For specific details, please refer to Figure 10 A more detailed description of the vibration pattern of the piezoelectric actuator structure when the valve is in the vibrating / open state. Figure 10 This is a schematic cross-sectional view along section line CC when the piezoelectric actuated structure is in a vibrating or open state. It can be understood that... Figure 10 This is a typical example of the valve being in the open state; the valve can also be in other open states. Figure 10 In this process, a voltage is applied to the piezoelectric films of the three intermediate fixed supports 3 piezoelectric actuation structures, causing them to displace in the same direction. This, combined with the concave arc structure of the outer frame, creates an opening 7 that allows fluid flow. The principle behind this open state is that... Figure 10 When a voltage is applied to the piezoelectric diaphragm, the piezoelectric actuation structure vibrates downwards in a bending motion. During this downward vibration, the gap between the outer frame and the piezoelectric actuation structure gradually increases, forming opening 7. It is understood that a concave arc structure exists on the entire inner side of the valve outer frame 1, creating a gap between this structure and the free end of each supporting component, allowing for a significant degree of valve opening. Furthermore, since the opening 7 between the outer frame and the piezoelectric actuation structure opens immediately and gradually increases during the displacement of the piezoelectric actuation structure, this control is stepless, fulfilling the performance requirement of stepless adjustment for active valve control.
[0103] Example 4: Single rectangular piezoelectric actuation structure with three fixed supports in the middle:
[0104] The above are all based on multiple intermediate fixed-support 3 piezoelectric actuation structural components, with channels formed between the piezoelectric actuation structural components and between the piezoelectric actuation structural components and the outer frame. To obtain a simpler valve structure, a single intermediate fixed-support 3 piezoelectric actuation structural component can also be used in conjunction with the outer frame structure to form the valve channel opening 7. This embodiment is a rectangular valve structure, with a single rectangular piezoelectric actuation structural component. Figure 11 and Figure 12 The figures shown are schematic diagrams of valves in an unactuated state. Figure 11 It is a bottom view. Figure 12 The image shows a cross-sectional view of the valve along section line EE. Both images show the valve in a flat state, with a small gap (micrometer (µm) between the piezoelectric actuation structure and the outer frame, indicating the valve is closed. The layered distribution of the valve can be observed more clearly in the cross-sectional view. The piezoelectric actuation structure consists of an upper electrode 5, a piezoelectric material 4, a lower electrode 6, and a diaphragm layer, deposited on a square support component to form a movable part. Applying voltage to the piezoelectric actuation structure causes it to displace.
[0105] Specifically, please refer to Figure 13 This describes the valve's state when it is in the actuated / open position. When voltage is applied to the piezoelectric actuator, both halves of the actuator displace downwards. At this time, the gap between the free ends of the two halves and the outer frame changes. Due to the concave arc structure on the inner sidewall of the outer frame, the gap gradually increases, forming opening 7. This method allows for stepless valve control based on the voltage applied. This valve has a simple structure and can meet the requirements for unidirectional fluid flow.
[0106] Example 5:
[0107] In the above structure, the number of support components is single, and multiple piezoelectric actuation structural components share one support component. In this embodiment, a valve structure composed of multiple support components will be shown. Figure 14 This is a rectangular valve structure with four supporting components, each supporting a piezoelectric actuation component. As shown in the figure, the valve structure includes four centrally fixed piezoelectric actuation components, and the valve outer frame 1 is a conventional vertical plane. Figure 14 and Figure 15The diagram shows a bottom view and a cross-sectional view of the outer frame in its closed state. It should be noted that the four intermediate fixed-support piezoelectric actuation structures are considered to be essentially flat, representing the closed state of the valve and being unenergized. In other aspects, each piezoelectric actuation structure consists of a diaphragm layer and piezoelectric material 4, not shown in the diagram. The diaphragm covers the intermediate fixed-support element 3 and forms a free end through various gaps. The gap between the diaphragm and the valve is formed by the outer frame, the cantilever side of the diaphragm, and the support components. Then, the respective piezoelectric material 4 is applied over the diaphragm to drive the free end of the diaphragm to move vertically. Each piezoelectric actuation structure can be individually controlled by applying voltage to the piezoelectric film, allowing for individual vertical movement depending on the fluid flow control requirements.
[0108] Specifically, each piezoelectric actuation structure includes a diaphragm layer material and a piezoelectric layer material. When a voltage is applied to the piezoelectric layer material, it drives the free end of the support component to produce displacement. (See reference...) Figure 16 and Figure 17 A more detailed description of the vibration pattern of the piezoelectric actuator structure when the valve is in the vibrating / open state. Figure 16 and Figure 17 These are schematic cross-sectional views along sections FF and GG, respectively, showing the piezoelectric actuated structure in a vibrating or open state. It is understandable that... Figure 16 and Figure 17 This example illustrates a typical open state of the valve; however, there are other ways the valve can be open. Figure 16 In the process, a voltage is applied to the piezoelectric actuator structure near the inner wall of the outer frame, causing it to displace downwards. Figure 17 Another pair of piezoelectric actuating components at this position are displaced upwards, opening the gap 2 between the piezoelectric actuating components and allowing fluid flow, thus forming an opening 7. Similarly, two adjacent piezoelectric actuating components on one side of the gap 2 between the left and right piezoelectric actuating components are displaced in the opposite direction, also forming an opening 7. In this opening mode, the valve opening 7 will be very large, promoting fluid flow. This example is another variation of a centrally fixed-support type active valve. Through this combination of displacements of more centrally fixed-support piezoelectric actuating components 3, the valve opening can be more varied.
[0109] Normally open type:
[0110] Example 6:
[0111] The examples above illustrate a normally closed valve, meaning the valve is closed when not actuated or energized. However, in practical applications, valves are more likely to be open. Therefore, if a valve can remain open even without energization, it will reduce power consumption and extend its lifespan. In this example, such as... Figure 18 and Figure 19 The diagram shows a bottom view and a cross-sectional view along section line HH of the valve in its unactuated / energized state. In this state, the four intermediate fixed-support piezoelectric actuation components are considered substantially flat, but due to the recessed structure, the valve is in the open state, allowing fluid or sound waves to flow through opening 7. The initial size of opening 7 can be achieved through different designs. In special cases, if a larger opening 7 is desired than the initial size, it can be controlled by displacing the piezoelectric actuation components. Specifically, each piezoelectric actuation component includes a diaphragm layer material and a piezoelectric layer material. Applying voltage to the piezoelectric layer material drives the free end of the support component to displace.
[0112] For reference Figure 20 A more detailed description of the vibration pattern of the piezoelectric actuator structure when the valve is in a vibrating / closed state. Figure 20 This is a schematic diagram of the cross-section obtained along section line HH when the piezoelectric actuated structure is in a vibrating or closed state. Figure 20 In this example, a voltage is applied to the piezoelectric actuator, causing it to displace upwards. Combined with the concave arc structure of the outer frame, the valve changes from an open to a closed state. Meanwhile, two adjacent piezoelectric actuators on one side of the gap 2 between the actuators are displaced in the same direction, resulting in a very small opening 7, which can be considered as the valve being closed. This example demonstrates a centrally fixed-support type active valve in a normally open state, expanding its practical application scenarios.
[0113] Normally closed bidirectional:
[0114] Example 7:
[0115] The examples above illustrate normally closed or normally open unidirectional flow-type active valves. However, in some applications, bidirectional opening of the valve is required, allowing for more flexible adjustment based on fluid or acoustic pressure. This invention patent can not only achieve unidirectional opening but also bidirectional opening of the valve. For example... Figure 21 and Figure 22The diagram shows a bottom view of the valve in its non-actuated / closed state and a cross-sectional view along section line II. In this state, the valve is considered substantially flat. The gaps 2 between each of the multiple piezoelectric actuation structures and the outer frame, as well as the gaps 2 between each piezoelectric actuation structure, are very small, approximately on the micrometer (µm) level. Therefore, the valve is considered closed. The outer frame 1 has arc-shaped recesses on both the upper and lower sides of the gaps between the valve's outer frame 1 and the piezoelectric actuation structures. These recesses do not affect the closed state of the valve when it is stationary. In other aspects, each piezoelectric actuation structure consists of a diaphragm layer and piezoelectric material 4. The diaphragm covers the central fixed support element 3 and forms free ends through various gaps. Then, the respective piezoelectric material 4 covers the diaphragm, thereby driving the free ends of the diaphragm to produce vertical displacement.
[0116] For specific details, please refer to Figure 23 and Figure 24 A more detailed description of the vibration patterns of the piezoelectric actuation structure when the valve is in the actuated / open state. Figure 23 This is a schematic cross-sectional view along section line II when the piezoelectric actuated structure is in the downward open / closed state. Figure 23 When a voltage is applied to the piezoelectric actuator, it is displaced downwards. In conjunction with the concave arc structure of the outer frame, the valve changes from a closed state to an open state in the downward direction, allowing fluid to flow from top to bottom. Figure 24 This is a schematic cross-sectional view along section line HH when the piezoelectric actuated structure is in the upward open / closed state. Figure 24 Applying voltage to the piezoelectric actuator causes it to move upwards. Combined with the recessed arc structure on the upper part of the outer frame, the valve changes from a closed state to an open state, allowing fluid to flow from bottom to top. This bidirectional valve structure can open upwards or downwards depending on the direction of fluid pressure, thus avoiding the obstruction caused by the pressure direction being opposite to the vibration direction of the piezoelectric actuator when voltage is applied to open the valve, resulting in more flexible characteristics.
[0117] 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. An active valve based on a centrally fixed piezoelectric diaphragm, characterized in that, It includes a non-piezoelectric actuation structure and at least one piezoelectric actuation structure; The non-piezoelectric actuation structure includes an outer frame (1) and a support component. The outer frame (1) forms the overall frame of the valve, and the support component is used to support and fix the piezoelectric actuation structure. The piezoelectric actuation structure is used to control the formation of airflow / liquid flow channels to control the opening and closing of the valve. A gap (2) is provided between the piezoelectric actuation structure and the outer frame (1) of the non-piezoelectric actuation structure, or between the piezoelectric actuation structures when there are multiple piezoelectric actuation structures, or between the piezoelectric actuation structure and the outer frame (1) and between the piezoelectric actuation structures. The gap (2) is opened to form an airflow / liquid flow channel. The piezoelectric actuation structure is fixed to the support component in the form of an intermediate fixed support (3); the piezoelectric actuation structure contains at least a piezoelectric material (4), and different voltages are applied to the piezoelectric actuation structure to cause the actuation structure to move, so as to control the opening and closing of the valve.
2. The active valve based on a centrally fixed piezoelectric diaphragm according to claim 1, characterized in that: The piezoelectric actuation structure is one of the following shapes: conical, trapezoidal, rectangular, or fan-shaped.
3. An active valve based on a centrally fixed piezoelectric diaphragm according to claim 1, characterized in that: The number of the support components is one or more.
4. An active valve based on a centrally fixed piezoelectric diaphragm according to claim 1, characterized in that: The plurality of piezoelectric actuation components can be arranged in a spiral shape, or in a mirror-image arrangement (left-right / up-down).
5. An active valve based on a centrally fixed piezoelectric diaphragm according to claim 1, characterized in that: The piezoelectric actuation structure has an upper electrode (5) and a lower electrode (6) made of a metal material on both the top and bottom of the piezoelectric material (4). The surface of the upper electrode (5) or the lower electrode (6) is connected to a diaphragm layer, and the diaphragm layer is a non-active material, which makes the displacement of the piezoelectric actuation structure larger.
6. An active valve based on a centrally fixed piezoelectric diaphragm according to claim 1, characterized in that: Each piezoelectric actuation structure is divided into two halves. One half is subjected to voltage to generate displacement in a first direction, while the other half is displaced in the opposite or the same direction as the first direction, which can be controlled separately.
7. An active valve based on a centrally fixed piezoelectric diaphragm according to claim 1, characterized in that: The valve is in a normally closed or normally open state. The displacement generated by each piezoelectric actuation component causes the valve to change to an open or closed state, allowing or hindering fluid flow through the position controlled by the valve.
8. An active valve based on a centrally fixed piezoelectric diaphragm according to claim 1, characterized in that: The inner wall of the outer frame adjacent to each free end of the piezoelectric actuation structure is a conventional vertical plane or has a recessed structure.
9. An active valve based on a centrally fixed piezoelectric diaphragm according to claim 8, characterized in that: The recessed structure on the inner sidewall of the outer frame allows the valve to be immediately in an open or closed state after the piezoelectric actuation component is displaced by the applied voltage. The degree of the opening (7) can be measured according to the degree of displacement of the piezoelectric actuation component, and stepless control of the valve can be achieved.
10. An active valve based on a centrally fixed piezoelectric thin film and its application as described in claim 8, characterized in that: The recessed structure on the outer frame sidewall, combined with the displacement of the piezoelectric actuation structure, can achieve unidirectional or bidirectional flow control of the valve. Unidirectional flow control allows the fluid to flow in only one direction, while bidirectional flow control allows the fluid to flow in one direction while achieving directional adjustability.
11. An active valve based on a centrally fixed piezoelectric thin film and its application according to claim 1, characterized in that: The support components are typically made of silicon, glass, or polymer materials.
12. An application of the active valve based on a centrally fixed piezoelectric thin film as described in any one of claims 1-11, characterized in that, Applications include miniature heat sinks, bone conduction headphones, bone conduction glasses, wired headphones, wireless headphones, smartwatches, smart bracelets, AR glasses, VR glasses, biomedical infusion pumps, and other electronic devices where a perfect balance between sealing and open operation is desired.