An acoustic atomizing chip and a manufacturing method thereof

Abstract

The application discloses an acoustic atomization chip and a manufacturing method thereof. The acoustic atomization chip comprises a piezoelectric substrate, a transducer, a protective layer, a transition connecting layer, a supporting layer and a liquid transmission medium; the transducer is arranged on the upper surface of the piezoelectric substrate, the protective layer covers the upper surface of the transducer, and the lower surface of the piezoelectric substrate is tightly combined with the supporting layer through the transition connecting layer; the transducer comprises two groups of symmetrical interdigital transducers, can excite two columns of mechanical vibration sound waves of megahertz frequency which propagate in opposite directions on the surface of the piezoelectric substrate; the piezoelectric substrate and the supporting layer are respectively provided with a first containing hole and a second containing hole in the region corresponding to the aperture range of the transducer, and the liquid transmission medium is arranged in the region space defined by the first containing hole and the second containing hole to form a medium transmission channel.

Description

Technical Field

[0001] This invention belongs to the field of atomization technology, and specifically relates to an acoustic atomization chip and its manufacturing method. Background Technology

[0002] One effective treatment for respiratory diseases is nebulized inhalation. This method uses a nebulizer to disperse medication into tiny droplets or particles, suspending them in a gas and allowing them to enter the respiratory tract and lungs to treat respiratory illnesses. Compared to other methods, nebulized inhalation offers advantages such as lower drug dosage, faster efficacy, fewer side effects, less pain, and avoidance of the first-pass effect in the liver, due to the large respiratory surface area and rich blood supply to the lungs.

[0003] Nebulizers have undergone continuous iteration, evolving through three generations: ultrasonic nebulizers, compressor nebulizers, and mesh nebulizers. Ultrasonic nebulizers, due to their high-temperature thermal cavitation output which can damage biomolecules and drug structures, their relatively large particle size, and the large amount of residual liquid, have gradually been phased out of the market. Compressor nebulizers are noisy, bulky, inconvenient, energy-intensive, and require electricity. Mesh nebulizers have low drug-liquid compatibility, and their mesh is prone to clogging and bacterial growth, affecting the device's droplet dispersion stability and lifespan.

[0004] In recent years, a novel surface acoustic wave (SAW) atomizer based on SAW technology has been proposed. It utilizes the inverse piezoelectric effect of piezoelectric materials to convert high-frequency electrical signals into nanoscale amplitude SAW signals. Placing the liquid in the SAW transmission path allows it to absorb sound wave energy, further forming surface capillary waves on the liquid surface, directly dispersing the liquid into aerosol droplets. This method eliminates the need for mesh to confine the liquid, high-speed airflow guidance, high shear stress, and cavitation thermal reactions, exhibiting good biocompatibility. It also boasts broad applicability to various medications, including suspensions and emulsions, representing a new direction for future atomization technology development. Summary of the Invention

[0005] To enrich the process routes and increase the selection space of surface acoustic wave atomizers, this invention provides an acoustic atomization chip and its fabrication method.

[0006] In a first aspect, embodiments of the present invention provide an acoustic atomizing chip, comprising: a piezoelectric substrate 1, a transducer 2, a protective layer 3, a transition connection layer 4, a support layer 5, and a liquid transport medium 6;

[0007] The transducer 2 is disposed on the upper surface of the piezoelectric substrate 1, the protective layer 3 covers the upper surface of the transducer 2, and the lower surface of the piezoelectric substrate 1 is tightly attached to the support layer 5 through the transition connection layer 4;

[0008] The transducer 2 includes two sets of symmetrical interdigital transducers, which can excite two columns of mechanical vibration sound waves with a megahertz frequency propagating in opposite directions on the surface of the piezoelectric substrate 1.

[0009] The piezoelectric substrate 1 and the support layer 5 are respectively provided with a first receiving hole 11 and a second receiving hole 51 in the region corresponding to the aperture range of the transducer 2. The liquid transmission medium 6 is disposed in the region space defined by the first receiving hole 11 and the second receiving hole 51 to form a medium transmission channel.

[0010] In one or more optional embodiments, the piezoelectric substrate 1 has a first receiving hole 11 in its central region, and the support layer 5 has a second receiving hole 51 in its central region, with the center lines of the first receiving hole 11 and the second receiving hole 51 coinciding.

[0011] In one or more optional embodiments, the distance between the edge line of the first receiving hole 11 perpendicular to the finger strip of the transducer 2 and the inner edge line of the transducer 2 is greater than a first preset distance value; the edge line of the first receiving hole 11 parallel to the finger strip of the transducer 2 does not exceed the aperture range of the transducer 2.

[0012] In one or more alternative embodiments, the size of the second receiving hole 51 is smaller than the size of the first receiving hole 11.

[0013] In one or more optional embodiments, the liquid transport medium 6 has a groove 61 in the middle region, the bottom of the groove 61 being lower than the upper surface of the piezoelectric substrate 1 and higher than the upper surface of the support layer 5.

[0014] In one or more alternative embodiments, the distance between the center line of the groove 61 and the center line of the transducer 2 is less than a preset distance range.

[0015] In one or more alternative embodiments, the centerline of the liquid transport medium 6, the centerline of the groove 61, and the centerline of the transducer 2 coincide.

[0016] In one or more optional embodiments, the transducer 2 includes a first set of interdigital electrodes 21, a second set of interdigital electrodes 22, a first set of reflective electrodes 23, a second set of reflective electrodes 24, a first bus electrode 25, and a second bus electrode 26.

[0017] The second set of interdigital electrodes 22 are arranged in parallel and opposite to the first set of interdigital electrodes 21;

[0018] The first set of interdigitated electrodes 21 includes a first electrode strip 211 and a second electrode strip 212 arranged in parallel and intersecting directions;

[0019] The second set of interdigitated electrodes 22 includes a third electrode strip 221 and a fourth electrode strip 222 arranged in parallel and intersecting directions;

[0020] The upper ends of the first electrode strip 211 and the third electrode strip 221 are connected to the first bus electrode 25, and the lower ends of the second electrode strip 212 and the fourth electrode strip 222 are connected to the second bus electrode 26.

[0021] The first set of reflective electrodes 23 are arranged in parallel to the left side of the first set of interdigital electrodes 21, and the second set of reflective electrodes 24 are arranged in parallel to the right side of the second set of interdigital electrodes 22.

[0022] In one or more optional embodiments, the first set of interdigital electrodes 21, the second set of interdigital electrodes 22, the first set of reflective electrodes 23, and the second set of reflective electrodes 24 are straight in shape;

[0023] The upper ends of the first electrode strip 211 and the third electrode strip 221 are rounded outwards, and the lower ends of the second electrode strip 212 and the fourth electrode strip 222 are rounded outwards.

[0024] The lower ends of the first electrode strip 211 and the third electrode strip 221 are rounded towards the inside of the electrode, and the upper ends of the second electrode strip 212 and the fourth electrode strip 222 are rounded towards the inside of the electrode.

[0025] Both ends of the first set of reflective electrodes 23 and the second set of reflective electrodes 24 are rounded inward.

[0026] In one or more optional embodiments, the piezoelectric substrate 1 includes a piezoelectric layer 12, a functional layer 13, a power-limiting layer 14 and a substrate 15 arranged sequentially from top to bottom;

[0027] The piezoelectric layer 12 is used as a wave transmission medium;

[0028] The functional layer 13 is used to balance the temperature coefficient of the piezoelectric layer 12;

[0029] The energy-limiting layer 14 is used to confine the acoustic wave energy to the surface of the piezoelectric layer 12 and suppress bulk wave leakage;

[0030] The substrate 15 is used to enhance the mechanical strength of the piezoelectric substrate 1 and increase the power capacity of the piezoelectric substrate 1.

[0031] In one or more optional embodiments, the piezoelectric layer 12 is made of a single-layer or multilayer material with piezoelectric properties, the functional layer 13 is made of a material with negative temperature compensation properties, and the energy-limiting layer 14 is made of a high-impedance acoustic material with a large difference in sound velocity from the piezoelectric layer 12.

[0032] In one or more alternative embodiments, the transition connection layer 4 is made of a material with high thermal conductivity.

[0033] In one or more alternative embodiments, the ratio of the thickness of the piezoelectric layer 12 to the period of the first set of interdigital electrodes 21 and the second set of interdigital electrodes 22 of the transducer ranges from 0.4 to 0.6.

[0034] In one or more optional embodiments, the spacing between the first set of interdigital electrodes 21 and the second set of interdigital electrodes 22 satisfies the following constraint:

[0035] L = N·λ / 2;

[0036] Where λ is the period of the interdigitated electrodes; L is the distance between the first group of interdigitated electrodes 21 and the second group of interdigitated electrodes 22; N is an integer, indicating that L is an integer multiple of half the wavelength of the surface acoustic wave;

[0037] In one or more optional embodiments, the first electrode strip 211, the second electrode strip 212, the third electrode strip 221, and the fourth electrode strip 222 have the same length.

[0038] In one or more alternative embodiments, the distance between the lower ends of the first electrode strip 211 and the third electrode strip 221 and the second bus electrode 26 is equal to the distance between the second electrode strip 212 and the fourth electrode strip 222 and the first bus electrode 25.

[0039] In one or more optional embodiments, the distance between the lower ends of the first electrode strip 211 and the third electrode strip 221 and the second bus electrode 26 satisfies the following constraint condition with respect to the period of the interdigitated electrodes:

[0040] λ / 4≤d≤2λ;

[0041] The distance between the second electrode strip 212 and the fourth electrode strip 222 and the first bus electrode 25:

[0042] λ / 4≤d≤2λ;

[0043] Where λ is the period of the interdigitated electrode; d is the distance between the lower end of the first electrode strip 211 and the second bus electrode 26, which is equal to the distance between the lower end of the third electrode strip 221 and the second bus electrode 26, which is equal to the distance between the second electrode strip 212 and the first bus electrode 25, which is equal to the distance between the fourth electrode strip 222 and the first bus electrode 25.

[0044] In one or more alternative embodiments, the first bus electrode 25 further includes a first bus terminal 251, and the second bus electrode 26 further includes a second bus terminal 261.

[0045] In one or more alternative embodiments, the ratio of the thickness of the transducer 2 to the period of the interdigitated electrode ranges from t / λ = 0.0005 to 0.015.

[0046] In one or more optional embodiments, the widths of the first electrode strip 211, the second electrode strip 212, the third electrode strip 221, and the fourth electrode strip 222 are the same;

[0047] The ratio of the width of the first electrode strip 211 to the distance between the first electrode strip 211 and the second electrode strip 212 is in the range of 0.1 to 0.9;

[0048] The ratio of the width of the third electrode strip 221 to the distance between the third electrode strip 221 and the fourth electrode strip 222 is in the range of 0.1 to 0.9.

[0049] In one or more alternative embodiments, the ratio of the transducer aperture to the period of the interdigitated electrode ranges from 20 to 100.

[0050] In one or more alternative embodiments, the ratio of the thickness of the protective layer 3 to the period of the interdigitated electrode ranges from 0.001 to 0.03.

[0051] In a second aspect, embodiments of the present invention provide a method for manufacturing the acoustic atomizing chip described in the first aspect, comprising:

[0052] The mask pattern of the prepared transducer is transferred to the surface of the carrier substrate to form transducer 2;

[0053] A protective layer 3 is formed on the non-bonded area of ​​the transducer 2 by sputtering or chemical vapor deposition.

[0054] The carrier substrate is attached to the carrier film, cut, baked or irradiated with ultraviolet light, and then peeled off or separated by a pick-up process to obtain an independent piezoelectric substrate 1;

[0055] A first receiving hole 11 is processed using a pulsed laser in the region of the piezoelectric substrate 1 corresponding to the aperture range of the transducer 2;

[0056] A second receiving hole 51 is prepared in the support layer 5 at a position corresponding to the first receiving hole 11;

[0057] The lower surface of the piezoelectric substrate 1 is bonded to the upper surface of the support layer 5 using the transition connection layer 4;

[0058] A pressing process is used to inject the liquid transfer medium 6 into the area defined by the first receiving hole 11 and the second receiving hole 51.

[0059] The embodiments of the present invention achieve at least the following beneficial effects:

[0060] The acoustic atomizing chip provided in this invention, by setting a first accommodating hole and a second accommodating hole in the substrate region and support layer region between two sets of symmetrical interdigital transducers, and combining this with the liquid transport medium embedded in the first and second accommodating holes, effectively utilizes the amplitude gradient effect of the double shear direction generated by the sound waves excited by the transducers at the edge of the first accommodating hole to form a significant negative pressure zone in the axial direction of the first and second accommodating holes, driving the directional migration of liquid in the liquid transport medium. The sharp edge characteristics of the first accommodating hole generate a capillary focusing effect, causing the drug liquid drawn to the edge to form a narrow, micron-sized thin liquid film with controllable thickness. This thin liquid film undergoes Rayleigh-Taylor instability under the action of mechanical vibration sound waves, achieving full dispersion and atomization of the liquid, ensuring a high degree of uniformity in aerosol particle size distribution. Based on the self-regulating liquid supply mechanism established by the axial negative pressure of the first and second accommodating holes, the synergistic effect of the capillary action of the liquid transport medium and the negative pressure suction achieves a dynamic balance between the liquid supply rate and the atomization rate, avoiding the problems of low atomization efficiency and waste caused by drug accumulation and ineffective atomization. Through the symmetrical layout of the transducer and the strong edge effect of the first accommodating hole, the spray direction of the atomized aerosol is always stably perpendicular to the surface of the piezoelectric substrate, which can ensure the precise delivery of drugs to the target respiratory area.

[0061] The acoustic atomizing chip provided in this invention, through a multi-layer composite structure design of piezoelectric substrate-transition connection layer-support layer, can quickly transfer the heat generated by losses in the piezoelectric substrate to the support layer, equalize the temperature distribution in different areas of the piezoelectric substrate, and gradually disperse thermal stress from the upper surface to the lower surface of the piezoelectric substrate, thus homogenizing the stress distribution and effectively reducing the thermal stress caused by the temperature gradient in the piezoelectric substrate. Furthermore, the support layer can withstand a certain pressure to protect the piezoelectric substrate, while simultaneously homogenizing the heat generated by material losses in the piezoelectric substrate itself, reducing concentrated thermal stress, effectively suppressing the heat accumulation effect under continuous high-power drive, extending the service life of the acoustic atomizing chip, significantly improving the power tolerance of the acoustic atomizing chip, enabling it to withstand higher power thresholds and achieve a wider adjustable power range. Based on the dispersion of thermal stress and the improvement of power tolerance, it helps to improve the vibration efficiency of the piezoelectric substrate, allowing the mechanical energy generated by the piezoelectric substrate to be converted into liquid surface energy more efficiently, thereby significantly improving the atomization capability of the acoustic atomizing chip.

[0062] The acoustic nebulization chip provided in this invention utilizes a wider adjustable power range, which can broaden the adjustable range of atomized aerosol particle size. At low power, the atomized particles are smaller, making it suitable for targeted drug delivery to the lower respiratory tract and lungs. In the high power range, the aerosol particle size is appropriately expanded to meet the needs of upper respiratory tract mucosal inhalation therapy. This linearly adjustable characteristic of power and particle size provides a highly flexible solution for medical nebulization applications in multiple scenarios.

[0063] The acoustic atomizing chip provided in this invention uses a material with negative temperature compensation characteristics for its functional layer. Its coefficient of thermal expansion is gradient-matched with that of the piezoelectric layer. Through a thermal stress compensation mechanism, the overall temperature coefficient is significantly reduced, which significantly suppresses frequency migration caused by temperature fluctuations and makes the operating frequency of the acoustic atomizing chip more stable. The energy-limiting layer is composed of a high-impedance acoustic material. Through the sound wave reflection effect, the mechanical vibration energy is limited to the thin piezoelectric layer, which effectively avoids the energy dissipation of sound waves in the thickness direction, thereby improving the sound energy utilization rate and enhancing the driving capability of the acoustic atomizing chip. At the same time, combined with a high thermal conductivity substrate material, the heat generation capacity of the acoustic atomizing chip can be effectively reduced, the dissipation temperature of the acoustic atomizing chip can be lowered, the performance degradation caused by local overheating can be effectively avoided, and the device life can be extended.

[0064] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0065] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0066] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0067] Figure 1 This is a schematic diagram of the structure of an acoustic atomizing chip provided in an embodiment of the present invention;

[0068] Figure 2 This is an exploded view of an acoustic atomizing chip provided in an embodiment of the present invention;

[0069] Figure 3 This is a cross-sectional view of an acoustic atomizing chip provided in an embodiment of the present invention;

[0070] Figure 4 This is a schematic diagram of the substrate structure provided in an embodiment of the present invention;

[0071] Figure 5This is a schematic diagram of the structure of the interdigital transducer provided in an embodiment of the present invention;

[0072] Figure 6 This is a flowchart of the manufacturing method of Embodiment 2 provided in this invention;

[0073] In the picture:

[0074] 1. Piezoelectric substrate; 11. First accommodating hole; 12. Piezoelectric layer; 13. Functional layer; 14. Energy-limiting layer; 15. Substrate; 2. Transducer; 21. First set of interdigitated electrodes; 211. First electrode strip; 212. Second electrode strip; 22. Second set of interdigitated electrodes; 221. Third electrode strip; 222. Fourth electrode strip; 23. First set of reflective electrodes; 24. Second set of reflective electrodes; 25. First bus electrode; 251. First bus terminal; 26. Second bus electrode; 261. Second bus terminal; 3. Protective layer; 4. Transition connection layer; 5. Support layer; 51. Second accommodating hole; 6. Liquid transport medium; 61. Groove. Detailed Implementation

[0075] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0076] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0077] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0078] The inventors, referring to existing technologies, discovered that current novel surface acoustic wave (SAW) atomizers based on SAW atomization technology suffer from problems such as an imbalance between liquid supply and atomization rate, poor stability of the atomized aerosol ejection direction, limited adjustable range of atomized droplet size, and high power consumption. These problems have been hindering the application and market transformation of SAW atomization technology in atomized inhalers.

[0079] To address this issue, the inventors proposed a method that utilizes a receiving hole in the substrate region between two sets of symmetrical interdigital transducers. Combined with a liquid transport medium embedded in the receiving hole, this effectively leverages the amplitude gradient effect in the dual shear directions generated by the acoustic waves excited by the transducers at the edge of the receiving hole. This creates a significant negative pressure zone along the axial direction of the receiving hole, driving the directional migration of liquid within the transport medium. The sharp edge of the receiving hole generates a capillary focusing effect, causing the drug drawn to the edge to form a narrow, micron-sized thin liquid film with controllable thickness. This thin film undergoes Rayleigh-Taylor instability under acoustic-mechanical vibration, achieving thorough dispersion and atomization of the liquid, ensuring a highly uniform aerosol particle size distribution. Based on the self-regulating liquid supply mechanism established by the axial negative pressure of the receiving hole, the synergistic effect of the capillary action of the liquid transport medium and the negative pressure suction achieves a dynamic balance between the liquid supply rate and the atomization rate, avoiding the problems of low atomization efficiency and waste caused by drug accumulation and ineffective atomization. Through the symmetrical layout of the transducers and the strong edge effect of the accommodating orifice, the spray direction of the atomized aerosol remains consistently perpendicular to the substrate surface, ensuring precise drug delivery to the target respiratory tract region. Furthermore, the multi-layer composite structure design of the piezoelectric substrate-transition connection layer-support layer uniformly distributes thermal stress, significantly improving the power tolerance of the acoustic atomization chip. This not only expands the adjustable range of atomized droplet size but also helps improve the vibration efficiency of the piezoelectric substrate, reducing power consumption during atomization, thereby significantly enhancing the atomization capability of the acoustic atomization chip. Based on these findings, this invention provides an acoustic atomization chip and its fabrication method.

[0080] Example 1

[0081] Reference Figures 1 to 3 As shown, an embodiment of the present invention provides an acoustic atomizing chip, comprising: a piezoelectric substrate 1, a transducer 2, a protective layer 3, a transition connection layer 4, a support layer 5, and a liquid transport medium 6;

[0082] The transducer 2 is disposed on the upper surface of the piezoelectric substrate 1, the protective layer 3 covers the upper surface of the transducer 2, and the lower surface of the piezoelectric substrate 1 is tightly attached to the support layer 5 through the transition connection layer 4;

[0083] The transducer 2 includes two sets of symmetrical interdigital transducers, which can excite two columns of mechanical vibration sound waves with a megahertz frequency propagating in opposite directions on the surface of the piezoelectric substrate 1.

[0084] The piezoelectric substrate 1 and the support layer 5 are respectively provided with a first receiving hole 11 and a second receiving hole 51 in the region corresponding to the aperture range of the transducer 2. The liquid transmission medium 6 is disposed in the region space defined by the first receiving hole 11 and the second receiving hole 51 to form a medium transmission channel.

[0085] The working principle of the acoustic atomizing chip provided in this embodiment of the invention is as follows: the liquid transport medium 6 absorbs and stores the liquid through capillary action. When an AC signal matching its characteristic response frequency is applied to the transducer 2, two opposing megahertz frequency mechanical vibration sound waves (hereinafter referred to as sound waves) are excited on the surface of the piezoelectric substrate 1. The excited sound waves have an amplitude gradient effect in two shear directions (i.e., the surface direction and axial direction of the first accommodating hole 11) at the edge of the first accommodating hole 11, forming a significant amplitude gradient in the axial direction of the first accommodating hole 11. The negative pressure zone drives the liquid in the liquid transport medium 6 to migrate in a directional manner, that is, drags the liquid in the liquid transport medium 6 to the edge of the first receiving hole 11. Combined with the sharp edge characteristics of the first receiving hole 11, a capillary focusing effect is generated, so that the liquid drawn to the edge forms a narrow-width micron-level thin liquid film (hereinafter referred to as thin liquid film) with controllable thickness. After absorbing the sound wave energy, the thin liquid film forms a high-frequency oscillating surface capillary wave on the surface. Under the action of the surface capillary wave, the liquid separates into small droplets at the wave crest, forming a stable jet atomization phenomenon perpendicular to the surface of the piezoelectric substrate 1.

[0086] The acoustic atomizing chip provided in this embodiment of the invention, by setting a first receiving hole 11 and a second receiving hole 51 in the substrate region and the support layer region between two sets of symmetrical interdigital transducers, and combining the liquid transport medium 6 embedded in the first receiving hole 11 and the second receiving hole 51, effectively utilizes the amplitude gradient effect of the double shear direction generated by the sound wave excited by the transducer 2 at the edge of the first receiving hole 11 to form a significant negative pressure zone in the axial direction of the first receiving hole 11 and the second receiving hole 51, driving the liquid in the liquid transport medium 6 to migrate in a directional manner. Combined with the sharp edge characteristics of the first receiving hole 11, a capillary focusing effect is generated, so that the liquid drawn to the edge forms a narrow-width micron-level thin liquid film with controllable thickness. This thin liquid film undergoes Rayleigh-Taylor instability under the action of mechanical vibration sound waves, realizing the full dispersion and atomization of the liquid and ensuring the high uniformity of the aerosol particle size distribution. The self-regulating liquid supply mechanism, established by the axial negative pressure of the first and second accommodating orifices 11 and 51, achieves a dynamic balance between the liquid supply rate and the atomization rate through the synergistic effect of the capillary action of the liquid transport medium 6 and the negative pressure suction. This avoids the problems of low atomization efficiency and waste caused by drug accumulation and ineffective atomization. Through the symmetrical layout of the transducer 2 and the strong edge effect of the first accommodating orifice 11, the spray direction of the atomized aerosol remains consistently perpendicular to the surface of the piezoelectric substrate 1, ensuring precise drug delivery to the target respiratory tract region.

[0087] The acoustic atomizing chip provided in this embodiment of the invention, through a multi-layer composite structure design of piezoelectric substrate 1-transition connection layer 4-support layer 5, can quickly transfer the heat generated by losses in the piezoelectric substrate 1 to the support layer 5, equalize the temperature distribution in various regions of the piezoelectric substrate 1, and gradually disperse the thermal stress from the upper surface to the lower surface of the piezoelectric substrate 1, thereby homogenizing the stress distribution and effectively reducing the thermal stress caused by the temperature gradient in the piezoelectric substrate 1. Furthermore, the support layer 5 can withstand a certain pressure to protect the piezoelectric substrate 1, while simultaneously homogenizing the thermal stress caused by the temperature gradient in the piezoelectric substrate 1. The heat generated by the material loss itself reduces concentrated thermal stress, which can effectively suppress the heat accumulation effect under continuous high power drive, improve the service life of the acoustic atomizing chip, significantly improve the power tolerance of the acoustic atomizing chip, and enable the acoustic atomizing chip to bear higher power thresholds and achieve a wider adjustable power range. Based on the thermal stress dispersion and improved power tolerance, it helps to improve the vibration efficiency of the piezoelectric substrate 1, so that the mechanical energy generated by the piezoelectric substrate 1 can be converted into liquid surface energy more efficiently, thereby significantly improving the atomization capability of the acoustic atomizing chip.

[0088] The acoustic nebulization chip provided in this invention utilizes a wider adjustable power range, which can broaden the adjustable range of atomized aerosol particle size. At low power, the atomized particles are smaller, making it suitable for targeted drug delivery to the lower respiratory tract and lungs. In the high power range, the aerosol particle size is appropriately expanded to meet the needs of upper respiratory tract mucosal inhalation therapy. This linearly adjustable characteristic of power and particle size provides a highly flexible solution for medical nebulization applications in multiple scenarios.

[0089] In one or more optional embodiments, the piezoelectric substrate 1 is composed of a single-layer or multi-layer material with piezoelectric properties, wherein at least one of piezoelectric single crystal, piezoelectric ceramic or piezoelectric thin film, such as lithium niobate, lithium tantalate, PZT, zinc oxide, aluminum nitride, etc.

[0090] Reference Figure 4 As shown, in one or more optional embodiments, the piezoelectric substrate 1 includes a piezoelectric layer 12, a functional layer 13, an energy-confining layer 14, and a substrate 15 arranged sequentially from top to bottom. The piezoelectric layer 12 serves as a wave transmission medium, the functional layer 13 is used to balance the temperature coefficient of the piezoelectric layer 12, and the energy-confining layer 14 is used to confine acoustic wave energy to the surface of the piezoelectric substrate 1 and suppress bulk wave leakage. The substrate 15 is used to enhance the mechanical strength of the piezoelectric substrate 1 and increase its power capacity.

[0091] In this embodiment of the invention, a composite structure design of piezoelectric layer 12-functional layer 13-energy-limiting layer 14-substrate 15-transition connection layer 4-support layer 5 is used to gradually disperse thermal stress from piezoelectric layer 12 towards substrate 15, thereby homogenizing the stress distribution and significantly improving the power tolerance of the acoustic atomizing chip. The heat accumulation effect under continuous high-power drive is effectively suppressed. Based on the dispersion of thermal stress and the improvement of power tolerance, the vibration efficiency of piezoelectric layer 12 is improved, enabling the mechanical energy generated by piezoelectric layer 12 to be converted into liquid surface energy more efficiently, thus significantly improving the atomization capability of the acoustic atomizing chip.

[0092] In this embodiment of the invention, the piezoelectric layer 12 is made of a single-layer or multi-layered material with piezoelectric properties, and the functional layer 13 is made of a material with negative temperature compensation characteristics. Its coefficient of thermal expansion is gradient-matched with that of the piezoelectric layer 12, and the overall temperature coefficient is significantly reduced through a thermal stress compensation mechanism, which significantly suppresses frequency migration caused by temperature fluctuations, making the operating frequency of the acoustic atomizing chip more stable. Furthermore, the energy-limiting layer 14 is made of a high-impedance acoustic material with a large difference in sound velocity from the piezoelectric layer 12. The mechanical vibration energy is confined to the piezoelectric layer 12 through the sound wave reflection effect, effectively avoiding energy dissipation of sound waves in the thickness direction, thereby improving sound energy utilization and enhancing the driving capability of the acoustic atomizing chip. Simultaneously, combined with a high thermal conductivity substrate material, the heat generation capacity of the acoustic atomizing chip can be effectively reduced, the dissipation temperature of the acoustic atomizing chip can be lowered, effectively avoiding performance degradation caused by local overheating and extending the device's lifespan.

[0093] In one specific embodiment, the piezoelectric layer 12 is preferably made of 128°YX LiNbO3, whose excitation acoustic wave has the Rayleigh mode as its dominant mode, exhibiting a large vertical shear displacement and strong driving capability for liquids. The functional layer 13 is preferably made of silicon dioxide, which has a positive temperature coefficient (TCF≈+20~+30ppm / ℃), which can balance the negative temperature coefficient of LiNbO3 (TCF≈-75~-90ppm / ℃), thereby suppressing the temperature drift of the acoustic atomization chip. The energy-limiting layer 14 is preferably made of a material with a large difference in sound velocity from the piezoelectric layer 12, such as aluminum nitride or diamond. Due to the large impedance difference caused by the sound velocity, the sound wave energy is not easily penetrated and leaked to the substrate 15, thus confining the sound wave energy within the piezoelectric layer 12. The substrate 15 is preferably made of a material with good support strength and thermal conductivity, such as silicon (150~163 W / m·K) or silicon carbide (490 W / m·K), which can better protect the brittle LiNbO3 material and prevent the piezoelectric layer 12 from cracking due to stress or temperature, thus effectively improving the power tolerance of the acoustic atomization chip.

[0094] In one specific embodiment, the ratio range (H / λ) of the thickness H of the piezoelectric layer 12 to the period λ of the designed interdigitated electrode is preferably 0.4~0.6 to obtain a large electromechanical coupling coefficient of >5%, while suppressing higher-order modes and improving the device quality factor (Q value). For example, if the period λ of the designed interdigitated electrode is 100μm, the thickness H of the piezoelectric layer 12 is 40μm~60μm, such as 40μm, 45μm, 50μm, 55μm, 60μm, etc.

[0095] In one specific embodiment, the transducer 2 is composed of a metallic material with good electrical conductivity, such as gold (Au), silver (Ag), aluminum (Al), copper (Cu), platinum (Pt), molybdenum (Mo), tungsten (W), etc.; it can be a single metallic material, a mixed metallic material, or an alloy of the above types, and in the thickness direction it can be a single-layer material or a multilayer material. In specific applications, it can be reasonably set according to the actual situation, and no specific limitation is made here.

[0096] In one specific embodiment, the material of transducer 2 is preferably tungsten (W) because tungsten metal has a higher shear modulus than other metals, which can achieve a larger electromechanical coupling coefficient.

[0097] Reference Figure 5 As shown, the transducer 2 includes a first set of interdigital electrodes 21, a second set of interdigital electrodes 22, a first set of reflective electrodes 23, a second set of reflective electrodes 24, a first bus electrode 25, and a second bus electrode 26. The first set of interdigital electrodes 21, the first set of reflective electrodes 23, the first bus electrode 25, and the second bus electrode 26 constitute one set of interdigital transducers, and the second set of interdigital electrodes 22, the second set of reflective electrodes 24, the first bus electrode 25, and the second bus electrode 26 also constitute one set of interdigital transducers. The second set of interdigital electrodes 22 is arranged parallel to and opposite to the first set of interdigital electrodes 21, and has the same parameters as the first set of interdigital electrodes 21. The distance between the first set of interdigital electrodes 21 and the second set of interdigital electrodes 22 is L.

[0098] Specifically, the first set of interdigitated electrodes 21 includes a first electrode strip 211 and a second electrode strip 212 arranged in parallel and intersecting directions. The width of the first electrode strip 211 and the second electrode strip 212 is 'a', and the distance between the first electrode strip 211 and the second electrode strip 212 is 'b', resulting in a period of λ=2(a+b) for the first set of interdigitated electrodes 211. The length of both the first electrode strip 211 and the second electrode strip 212 is 'l', and the overlap length between them is defined as the aperture W of the transducer 2. The second set of interdigitated electrodes 22 includes a third electrode strip 221 and a fourth electrode strip 222 arranged in parallel and intersecting directions. The width of both the third electrode strip 221 and the fourth electrode strip 222 is 'a', and the distance between the third electrode strip 221 and the fourth electrode strip 222 is 'b', resulting in a period of λ=2(a+b) for the second set of interdigitated electrodes 22. The length of both the third electrode strip 221 and the fourth electrode strip 222 is 'l', and the overlap length between them is the aperture W of the transducer 2. That is, the width and length of the first electrode strip 211, the second electrode strip 212, the third electrode strip 221 and the fourth electrode strip 222 are all the same, and the distance between the first electrode strip 211 and the second electrode strip 212 is equal to the distance between the third electrode strip 221 and the fourth electrode strip 222.

[0099] Reference Figure 5 As shown, the upper ends of the first electrode strip 211 and the third electrode strip 221 are connected to the first bus electrode 25, and the lower ends of the second electrode strip 212 and the fourth electrode strip 222 are connected to the second bus electrode 26. The distance between the lower ends of the first electrode strip 211 and the third electrode strip 221 and the second bus electrode 26 is d, and the distance between the second electrode strip 212 and the fourth electrode strip 222 and the first bus electrode 25 is also d.

[0100] Reference Figure 5 As shown, the first set of reflective electrodes 23 are arranged in parallel to the left side of the first set of interdigital electrodes 21, and the second set of reflective electrodes 24 are arranged in parallel to the right side of the second set of interdigital electrodes 22.

[0101] Reference Figure 5 As shown, the first bus electrode 25 further includes a first bus terminal 251, and the second bus electrode 26 further includes a second bus terminal 261.

[0102] In one or more optional embodiments, the ratio of the thickness t of the transducer 2 to the period λ of the interdigital electrodes (i.e., the period of the first set of interdigital electrodes 21 and the second set of interdigital electrodes 22) ranges from t / λ = 0.0005 to 0.015. The inventors have found that as the thickness of the transducer 2 increases, the mass loading effect becomes more pronounced, and its sound velocity consistently decreases. However, the corresponding electromechanical coupling coefficient first increases, then reaches its maximum value at a certain electrode thickness, and subsequently decreases with further increases in electrode thickness. Within this range, a relatively large electromechanical coupling coefficient can be guaranteed. For example, t / λ = 0.001; if λ = 200 μm, then t = 200 nm.

[0103] In one or more alternative embodiments, the shapes of the first set of interdigital electrodes 21, the second set of interdigital electrodes 22, the first set of reflective electrodes 23, and the second set of reflective electrodes 24 can be straight, arc-shaped, or conical at the same time.

[0104] Reference Figure 5 As shown, in a specific embodiment, the first set of interdigitated electrodes 21, the second set of interdigitated electrodes 22, the first set of reflective electrodes 23, and the second set of reflective electrodes 24 are straight in shape. Specifically, the ends of the first set of interdigitated electrodes 21 and the second set of interdigitated electrodes 22 that are not connected to the bus electrode are rounded inwards, while the ends connected to the bus electrode are rounded outwards. That is, the upper ends of the first electrode strip 211 and the third electrode strip 221 are rounded outwards, the lower ends of the second electrode strip 212 and the fourth electrode strip 222 are rounded outwards, the lower ends of the first electrode strip 211 and the third electrode strip 221 are rounded inwards, and the upper ends of the second electrode strip 212 and the fourth electrode strip 222 are rounded inwards. Furthermore, both ends of the first set of reflective electrodes 23 and the second set of reflective electrodes 24 are rounded inwards. The rounded corner design avoids sharp corners in the electrodes. Under the same voltage, the electric field intensity at the sharp corners of the electrodes is much higher than at other locations, which can easily cause point discharge, resulting in electric spark breakdown and damage to the electrodes. The rounded corners can effectively protect the electrodes and improve the working life of the transducer 2.

[0105] In one or more optional embodiments, the width 'a' of the electrode strips of the first set of interdigital electrodes 21 and the spacing 'b' of adjacent electrode strips should satisfy a / (a+b) = 0.1~0.9, that is, the ratio of the width of the first electrode strip 211 to the spacing between the first electrode strip 211 and the second electrode strip 212 is in the range of 0.1~0.9; the ratio of the width of the third electrode strip 221 to the spacing between the third electrode strip 221 and the fourth electrode strip 222 is in the range of 0.1~0.9. Such electrode strip width and spacing design can correspondingly increase the electromechanical coupling coefficient, thereby increasing the excitation surface acoustic wave energy. Specifically, a / (a+b) = 0.5, where the corresponding electromechanical coupling coefficient reaches its maximum value, maximizing the excitation surface acoustic wave energy.

[0106] In one or more optional embodiments, the ratio of the aperture W of the transducer 2 to the period λ of the interdigital electrode is in the range of W / λ=20~100. When the value of W / λ is too small, there will be a large second-order diffraction effect between the electrode strips. When the value of W / λ is too large, the sound wave energy is dispersed over a wide range, resulting in energy non-concentration. Both will weaken the sound wave energy. For example, W / λ=20, such as λ=200μm, then W=4000μm.

[0107] In one or more optional embodiments, the distance *d* between the end of the electrode strip and the busbar electrode satisfies λ / 4 ≤ d ≤ 2λ. That is, the distance between the lower ends of the first electrode strip 211 and the third electrode strip 221 and the second busbar electrode 26, and the period of the interdigitated electrodes, satisfies the following constraint: λ / 4 ≤ d ≤ 2λ; the distance between the second electrode strip 212 and the fourth electrode strip 222 and the first busbar electrode 25 is: λ / 4 ≤ d ≤ 2λ. When the distance between the end of the electrode strip and the busbar electrode is too small, acoustic energy easily leaks to the outside of the busbar electrode, posing a significant challenge to the precision requirements of the processing equipment. Conversely, when the distance is too large, the overall size of the acoustic atomizing chip increases, resulting in material waste and increased manufacturing costs. For example, d = λ / 4; if λ = 200 μm, then d = 50 μm.

[0108] In one or more optional embodiments, the spacing between the first set of interdigital electrodes 21 and the second set of interdigital electrodes 22 satisfies L = N·λ / 2, where N is an integer, indicating that L is an integer multiple of half the wavelength of the surface acoustic wave. In this case, the opposing acoustic waves excited by the first set of interdigital electrodes 21 and the second set of interdigital electrodes 22 superimpose in the middle region, forming an enhanced standing wave, which significantly improves the liquid atomization capability. For example, L = 50·λ / 2; if λ = 200 μm, then L = 5000 μm.

[0109] In one or more optional embodiments, the material of the protective layer 3 may be a single-layer material such as silicon dioxide, silicon nitride, phosphosilicate glass, or polyimide, or a combination of multiple laminated materials. It covers the upper surface of the transducer 2 to form a passivation film to prevent damage, oxidation, or corrosion of the surface of the metal material in the transducer 2, effectively slowing down the aging rate of the metal material and thus extending the service life of the transducer 2.

[0110] Reference Figure 2 As shown, the size of the hole in the middle region of the protective layer 3 is smaller than the size of the hole in the middle region of the transducer 2, so that the protective layer 3 can cover the non-bonded area on the surface of the transducer 2, thereby achieving effective protection of the electrodes. In this embodiment of the invention, the bonding area is the area where the first bus terminal 251 and the second bus terminal 261 are bonded to the electrode pins of the transducer 2, and the non-bonded area is the area other than the area where the first bus terminal 251 and the second bus terminal 261 are located.

[0111] In one or more alternative embodiments, the thickness t of the protective layer 3 p The ratio of the period λ of the interdigitated electrode to the period t satisfies the following range. p / λ=0.001~0.03. t p / λ being too small indicates that the protective layer is too thin, making it prone to breakdown and failure. p A large / λ indicates an excessively thick protective layer, which reduces the chip's electromechanical coupling coefficient, causing excessive energy leakage into the protective layer and weakening its ability to drive liquid atomization. For example, t p / λ=0.0015, if λ=200μm, then t p =300nm.

[0112] In one or more optional embodiments, the transition connection layer 4 is used to connect the piezoelectric substrate 1 and the support layer 5. The transition connection layer 4 is made of a material with high thermal conductivity. Preferably, it is a metallic or alloy material or other non-metallic material with high thermal conductivity, such as gold, nano-silver, graphene, etc. By connecting the piezoelectric substrate 1 and the support layer 5 through the transition connection layer 4, the heat generated by the loss in the piezoelectric substrate 1 can be quickly transferred to the support layer 5, the temperature distribution in different areas of the piezoelectric substrate 1 can be balanced, the thermal stress caused by the temperature gradient in the piezoelectric substrate 1 can be effectively reduced, and the service life of the atomizing chip can be improved. The inventors discovered that within the range of the aperture W of the transducer 2 in the piezoelectric substrate 1, the temperature at each cut edge along the direction of surface acoustic wave transmission is higher, exhibiting a temperature gradient distribution effect compared to other areas. The greater the input power, the greater the temperature gradient effect. The greater the temperature gradient in the piezoelectric substrate 1, the greater the corresponding thermal stress. At high thermal stress locations, the chip is more prone to cracking, causing the acoustic atomizing chip to fail. The atomization capability of the acoustic atomizing chip is also positively correlated with the input power. However, simply increasing the input power will significantly shorten the lifespan of the atomizing chip without achieving the goal of enhancing the atomization capability. By connecting the piezoelectric substrate 1 and the support layer 5 through the transition connection layer 4, the power tolerance of the acoustic atomizing chip can be effectively improved, thereby correspondingly enhancing the atomization capability of the acoustic atomizing chip.

[0113] Reference Figure 2 As shown, the size of the hole in the middle region of the transition connection layer 4 is consistent with the size of the second receiving hole 51.

[0114] In one or more optional embodiments, the support layer 5 is made of a material with certain rigidity and good thermal conductivity, and can be one of the following: a metal-based heat sink (copper, aluminum, etc.), a ceramic-based heat sink (alumina, aluminum nitride, silicon nitride, etc.), or an emerging carbon-based heat sink (graphite, carbon nanotubes, graphene, diamond, etc.). The support layer 5 can withstand a certain pressure to protect the piezoelectric substrate 1, while homogenizing the heat generated by the material loss of the piezoelectric substrate 1 itself, reducing concentrated thermal stress, and enabling the atomizing chip to withstand a higher power threshold. Through experimental testing, the inventors discovered that when the period λ of the interdigitated electrode is 200μm, the aperture W is 4000μm, the thickness H of the piezoelectric layer 12 is 90μm, and the electrode thickness t is 200nm, then H / λ = 0.45, W / λ = 20, and t / λ = 0.001. By adding a 10μm transition connection layer of nano-silver material and combining it with a 2mm thick aluminum material support layer 5, the load-bearing power of the piezoelectric substrate 1 can be increased from 8W to 25W, and the temperature uniformity can be improved by 30%.

[0115] In one or more alternative embodiments, the liquid transport medium 6 is a material with porous characteristics that can transfer liquids through capillary action, such as porous ceramics, porous glass, non-woven fabrics, linen, fiber cotton, fiberglass rope, etc.

[0116] Through experiments, the inventors discovered that when the pore size or porosity of the liquid transport medium 6 is too large, liquid tends to accumulate in the first receiving hole 11, leading to the ejection of large-sized droplets. Conversely, if the pore size or porosity of the liquid transport medium 6 is too small, the liquid supply rate will not keep up with the atomization rate, resulting in intermittent atomization and wasting acoustic energy. Therefore, the inventors proposed using porous ceramic with a porosity of 40%~60% and an average pore size of 30~50μm for the liquid transport medium 6, which can ensure a relative balance between a continuous and stable liquid supply and atomized aerosol.

[0117] In this embodiment of the invention, the liquid transport medium 6 can be disposed in the central region of the acoustic atomizing chip. Specifically, the central region of the piezoelectric substrate 1 may have a first receiving hole 11, and the central region of the support layer 5 may have a second receiving hole 51. The center lines of the first receiving hole 11 and the second receiving hole 51 coincide, thereby the liquid transport medium 6 is disposed within the area defined by the first receiving hole 11 and the second receiving hole 51 to form a medium transport channel.

[0118] In one or more optional embodiments, the shape of the first receiving hole 11 can be circular, elliptical, rectangular, or other irregularly shaped. The distance between the edge line of the first receiving hole 11 perpendicular to the fingers of the transducer 2 and the inner edge line of the transducer 2 must be greater than a first preset distance value. In this embodiment, the first preset distance value is 1 mm, meaning the distance between the liquid transport medium 6 and the edges of the first set of interdigital electrodes 21 and the second set of interdigital electrodes 22 is greater than 1 mm, to prevent the precipitated liquid film from covering the transducer 2 and affecting device performance. The edge line of the first receiving hole 11 parallel to the fingers of the transducer 2 does not exceed the aperture range, to prevent liquid outside the aperture from being atomized due to ineffective absorption of acoustic energy. In a specific embodiment, the first receiving hole 11 is rectangular in shape, with a width of 2 mm and a length and aperture W of 4 mm.

[0119] Reference Figure 2As shown, in one or more optional embodiments, the second receiving hole 51 disposed in the central region of the support layer 5 corresponds to the first receiving hole 11. The size of the second receiving hole 51 is smaller than the size of the first receiving hole 11. The liquid transmission medium 6 is disposed in the area space defined by the first receiving hole 11 and the second receiving hole 51 to form a medium transmission channel. In a specific embodiment, the length of the first receiving hole 11 is 0.1-0.3 mm larger than the second receiving hole 51, and the width of the first receiving hole 11 is 0.1-0.2 mm larger than the second receiving hole 51. The inventors discovered that when the difference between the length of the first receiving hole 11 and the length of the second receiving hole 51 is less than 0.1 mm, or when the difference between the width of the first receiving hole 11 and the width of the second receiving hole 51 is less than 0.1 mm, the piezoelectric substrate 1 at the edge of the first receiving hole 11 is prone to fragmentation when the liquid transmission medium 6 is pressed into the first receiving hole 11 and the second receiving hole 51. When the difference between the length of the first receiving hole 11 and the length of the second receiving hole 51 is greater than 0.3 mm, there will be a certain gap between the liquid transmission medium 6 and the left and right sides of the first receiving hole 11, which will prevent the sound waves from contacting the liquid to be atomized and prevent the energy from being transferred to the liquid for atomization.

[0120] Reference Figure 2 As shown, in one or more optional embodiments, the liquid transport medium 6 has a groove 61 in the middle region. The bottom of the groove 61 (i.e., the notch position) is lower than the upper surface of the piezoelectric substrate 1 and higher than the upper surface of the support layer 5. By setting the groove 61, atomization space is provided for the liquid to be atomized. At the same time, it can ensure that the large droplets generated during atomization fall into the groove 61 under the action of gravity, and are further absorbed by the liquid transport medium 6 for reuse, thereby improving the utilization efficiency of the liquid and reducing the waste of the liquid. During the atomization process, based on the self-regulating liquid supply mechanism established by the axial negative pressure of the first accommodating hole 11 and the second accommodating hole 51, the liquid transport medium 6 draws the liquid stored at the bottom of the acoustic atomizing chip to the areas on both sides of the groove 61 near the edge of the first accommodating hole 11. Combined with the sharp edge characteristics of the first accommodating hole 11, a capillary focusing effect is generated, so that the liquid drawn to the edge of the first accommodating hole 11 forms a narrow-width micron-level thin liquid film with controllable thickness, thereby achieving full dispersion and atomization of the liquid.

[0121] Reference Figure 1 As shown, the top of the groove 61 (i.e., the top surface of the groove) is higher than or flush with the upper surface of the piezoelectric substrate 1.

[0122] In one or more alternative embodiments, the distance between the centerline of the groove 61 and the centerline of the transducer 2 is less than a preset distance range. For example, the length of the groove 61 parallel to the electrode finger direction of the transducer 2 is L. gTherefore, the distance between the center line of the groove 61 and the center line of the transducer 2 should be less than L. g / 2.

[0123] In one specific embodiment, the centerline of the liquid transport medium 6, the centerline of the groove 61, and the centerline of the transducer 2 may coincide. For example, if the transducer 2 has an aperture of 4 mm and the liquid transport medium 6 has a length of 4 mm, the length of the groove 61 can be selected as 1.8 mm, 2.2 mm, 2.8 mm, 3.2 mm, etc. The grooves 61 may be symmetrically distributed and located in the middle region of the liquid transport medium 6.

[0124] Example 2

[0125] Based on the same inventive concept, this invention also provides a method for manufacturing an acoustic atomizing chip as described in Embodiment 1, comprising:

[0126] The mask pattern of the prepared transducer is transferred to the surface of the carrier substrate to form transducer 2;

[0127] A protective layer 3 is formed on the non-bonded area of ​​the transducer 2 by sputtering or chemical vapor deposition.

[0128] The carrier substrate is attached to the carrier film, cut, baked or irradiated with ultraviolet light, and then peeled off or separated by a pick-up process to obtain an independent piezoelectric substrate 1;

[0129] A first receiving hole 11 is processed using a pulsed laser in the region of the piezoelectric substrate 1 corresponding to the aperture range of the transducer 2;

[0130] A second receiving hole 51 is prepared in the support layer 5 at a position corresponding to the first receiving hole 11;

[0131] The lower surface of the piezoelectric substrate 1 is bonded to the upper surface of the support layer 5 using the transition connection layer 4;

[0132] A pressing process is used to inject the liquid transfer medium 6 into the area defined by the first receiving hole 11 and the second receiving hole 51.

[0133] To facilitate the fabrication of acoustic atomizing chips by those skilled in the art, and to obtain the acoustic atomizing chip provided in the embodiments of the present invention, the following describes... Figure 6 Taking the fabrication process of the acoustic atomizing chip shown as an example, the fabrication method of the acoustic atomizing chip provided in this embodiment of the invention will be described in detail below:

[0134] Step 1: Fabrication of piezoelectric substrate 1

[0135] A confinement layer 14 and a functional layer 13 are sequentially deposited on the surface of a polished substrate 15. Plasma is injected into the piezoelectric layer 12 of the single crystal material. The plasma-injected piezoelectric layer 12 is bonded to the substrate 15 with the confinement layer 14 and the functional layer 13 deposited. Heat treatment is then performed to peel off the thin film piezoelectric layer 12. The peeled thin film piezoelectric layer 12 is then thinned and polished to obtain a complete carrier substrate.

[0136] The second step is to arrange the graphic on the mask.

[0137] The transducer 2 layout is designed according to a matrix arrangement. The mask pattern is then arranged according to the transducer 2 layout. It is assumed that the direction of sound wave propagation is the X-axis and the direction perpendicular to the sound wave propagation is the Y-axis. The mask patterns of transducer 2 are arranged horizontally in a straight line at a spacing A in the X-axis direction, and vertically in a straight line at a spacing B in the Y-axis direction. Wherein: the width of A is greater than the width of the scribing, including the chipped edge, formed when the substrate is cut horizontally; the width of B is greater than the width of the scribing, including the chipped edge, formed when the substrate is cut vertically.

[0138] The transducer 2 includes two sets of symmetrical interdigital transducers, and their specific arrangement can be referred to in the above embodiment 1 regarding... Figure 5 A detailed description of it is omitted here.

[0139] Step 3: Transducer 2 fabrication

[0140] The mask pattern of the transducer 2 is transferred to the surface of the carrier substrate through photolithography, coating, stripping or etching processes to form the transducer 2.

[0141] Step 4: Creating Protective Layer 3

[0142] A dense protective layer 3 is formed on the unbonded area of ​​the transducer 2 surface by sputtering or chemical vapor deposition.

[0143] Step 5: Cutting and slicing piezoelectric substrate 1

[0144] The carrier substrate is attached to an adhesive carrier film such as a blue film or a UV film, and then cut along the center of chip spacing A and B using a dicing machine. The cutting depth is equal to the thickness of the substrate.

[0145] The cut individual piezoelectric substrates are baked or irradiated with ultraviolet light to reduce the adhesion of the carrier film, and then separated into independent piezoelectric substrates 1 using a peeling or pick-up process.

[0146] Step 6: Preparation of the first receiving hole 11

[0147] The first receiving hole 11 is processed in the middle region of the piezoelectric substrate 1 using a pulsed laser.

[0148] Step 7: Preparation of support layer 5 and second receiving hole 51

[0149] The support layer 5 of a specified shape is cut out using processes such as laser cutting, wire cutting or electrical cutting, and then the second receiving hole 51 is prepared at the position corresponding to the first receiving hole 11 using a laser or drill bit.

[0150] Step 8: Bonding the piezoelectric substrate 1 to the support layer 5

[0151] The bottom surface of the piezoelectric substrate 1 and the surface of the support layer 5 are bonded together by means of nano-silver sintering, ultrasonic thermo-press welding, or die bonding, using the transition connection layer 4.

[0152] Step 9: Install liquid transfer medium 6

[0153] The liquid transfer medium 6 is injected into the area defined by the first receiving hole 11 and the second receiving hole 51 using a pressing process.

[0154] The method for fabricating an acoustic atomizing chip provided in this invention involves setting a first receiving hole 11 and a second receiving hole 51 in the substrate region and the support layer region between two sets of symmetrical interdigital transducers, respectively. Combined with the liquid transport medium 6 embedded in the first and second receiving holes 11 and 51, the method effectively utilizes the amplitude gradient effect in the dual shear directions generated by the sound waves excited by the transducer 2 at the edge of the first receiving hole 11 to form a significant negative pressure zone along the axial direction of the first and second receiving holes 11 and 51, driving the directional migration of liquid in the liquid transport medium 6. The sharp edge characteristics of the first receiving hole 11 generate a capillary focusing effect, causing the drug liquid drawn to the edge to form a narrow, micron-sized thin liquid film with controllable thickness. This thin liquid film undergoes Rayleigh-Taylor instability under the action of mechanical vibration sound waves, achieving full dispersion and atomization of the liquid and ensuring a high degree of uniformity in the aerosol particle size distribution. The self-regulating liquid supply mechanism, established by the axial negative pressure of the first and second accommodating orifices 11 and 51, achieves a dynamic balance between the liquid supply rate and the atomization rate through the synergistic effect of the capillary action of the liquid transport medium 6 and the negative pressure suction. This avoids the problems of low atomization efficiency and waste caused by drug accumulation and ineffective atomization. Through the symmetrical layout of the transducer 2 and the strong edge effect of the first accommodating orifice 11, the spray direction of the atomized aerosol remains consistently perpendicular to the surface of the piezoelectric substrate 1, ensuring precise drug delivery to the target respiratory tract region.

[0155] The method for fabricating an acoustic atomizing chip provided in this invention utilizes a multi-layer composite structure design of a piezoelectric substrate 1, a transition connection layer 4, and a support layer 5. This allows for rapid transfer of heat generated by losses in the piezoelectric substrate 1 to the support layer 5, balancing the temperature distribution across different areas of the piezoelectric substrate 1. Thermal stress is gradually dispersed from the upper to the lower surface of the piezoelectric substrate 1, resulting in a more uniform stress distribution. This effectively reduces the thermal stress caused by the temperature gradient in the piezoelectric substrate 1. Furthermore, the support layer 5 can withstand a certain pressure to protect the piezoelectric substrate 1, while simultaneously homogenizing the heat generated by the piezoelectric substrate. The heat generated by the material loss of the substrate 1 itself reduces concentrated thermal stress, effectively suppresses the heat accumulation effect under continuous high power drive, improves the service life of the acoustic atomizing chip, significantly improves the power tolerance of the acoustic atomizing chip, and enables the acoustic atomizing chip to bear higher power thresholds and achieve a wider adjustable power range. Based on the dispersion of thermal stress and the improvement of power tolerance, it helps to improve the vibration efficiency of the piezoelectric substrate 1, so that the mechanical energy generated by the piezoelectric substrate 1 can be converted into liquid surface energy more efficiently, thereby significantly improving the atomization capability of the acoustic atomizing chip.

[0156] The method for fabricating an acoustic nebulization chip provided in this invention produces an acoustic nebulization chip with a wider adjustable power range. This wider adjustable power range allows for a broader range of adjustable aerosol particle size. At low power, the aerosol particles are smaller, making it suitable for targeted drug delivery to the lower respiratory tract and lungs. In the high power range, the aerosol particle size is appropriately expanded to meet the needs of upper respiratory tract mucosal inhalation therapy. This linearly adjustable power and particle size characteristic provides a highly flexible solution for multi-scenario medical nebulization applications.

[0157] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of equivalents of this invention, this invention also intends to include these modifications and variations.

Claims

1. An acoustic atomizing chip, characterized in that, include: Piezoelectric substrate (1), transducer (2), protective layer (3), transition connection layer (4), support layer (5) and liquid transport medium (6); The transducer (2) is disposed on the upper surface of the piezoelectric substrate (1), the protective layer (3) covers the upper surface of the transducer (2), and the lower surface of the piezoelectric substrate (1) is tightly attached to the support layer (5) through the transition connection layer (4); The transducer (2) includes two sets of symmetrical interdigital transducers, which can excite two columns of mechanical vibration sound waves with a frequency of megahertz propagating in opposite directions on the surface of the piezoelectric substrate (1). The piezoelectric substrate (1) and the support layer (5) are respectively provided with a first receiving hole (11) and a second receiving hole (51) in the area corresponding to the aperture range of the transducer (2). The liquid transmission medium (6) is disposed in the area space defined by the first receiving hole (11) and the second receiving hole (51) to form a medium transmission channel. The piezoelectric substrate (1) has a first receiving hole (11) in its central region and the support layer (5) has a second receiving hole (51) in its central region. The center lines of the first receiving hole (11) and the second receiving hole (51) coincide. The distance between the edge line of the first receiving hole (11) perpendicular to the finger strip of the transducer (2) and the inner edge line of the transducer (2) is greater than a first preset distance value; the edge line of the first receiving hole (11) parallel to the finger strip of the transducer (2) does not exceed the aperture range of the transducer (2); the size of the second receiving hole (51) is smaller than the size of the first receiving hole (11).

2. The acoustic atomizing chip as described in claim 1, characterized in that, The liquid transport medium (6) has a groove (61) in the middle area. The bottom of the groove (61) is lower than the upper surface of the piezoelectric substrate (1) and higher than the upper surface of the support layer (5).

3. The acoustic atomizing chip as described in claim 2, characterized in that, The distance between the center line of the groove (61) and the center line of the transducer (2) is less than the second preset distance value.

4. The acoustic atomizing chip as described in any one of claims 1-3, characterized in that, The transducer (2) includes a first set of interdigitated electrodes (21), a second set of interdigitated electrodes (22), a first set of reflective electrodes (23), a second set of reflective electrodes (24), a first bus electrode (25), and a second bus electrode (26). The second set of interdigital electrodes (22) are arranged in parallel opposite directions to the first set of interdigital electrodes (21); The first set of interdigitated electrodes (21) includes a first electrode strip (211) and a second electrode strip (212) arranged in parallel and intersecting directions. The second set of interdigitated electrodes (22) includes a third electrode strip (221) and a fourth electrode strip (222) arranged in parallel and intersecting directions. The upper ends of the first electrode strip (211) and the third electrode strip (221) are connected to the first bus electrode (25), and the lower ends of the second electrode strip (212) and the fourth electrode strip (222) are connected to the second bus electrode (26). The first set of reflective electrodes (23) are arranged in parallel to the left side of the first set of interdigital electrodes (21), and the second set of reflective electrodes (24) are arranged in parallel to the right side of the second set of interdigital electrodes (22).

5. The acoustic atomizing chip as described in claim 1, characterized in that, The piezoelectric substrate (1) includes a piezoelectric layer (12), a functional layer (13), an energy-limiting layer (14), and a substrate (15) arranged sequentially from top to bottom. The piezoelectric layer (12) is used as a wave transmission medium; The functional layer (13) is used to balance the temperature coefficient of the piezoelectric layer (12); The energy-limiting layer (14) is used to confine the acoustic wave energy to the surface of the piezoelectric layer (12) and suppress bulk wave leakage; The substrate (15) is used to enhance the mechanical strength of the piezoelectric substrate (1) and increase the power capacity of the piezoelectric substrate (1).

6. The acoustic atomizing chip as described in claim 5, characterized in that, The piezoelectric layer (12) is made of a single-layer or multilayer material with piezoelectric properties, the functional layer (13) is made of a material with negative temperature compensation properties, and the energy-limiting layer (14) is made of a high-impedance acoustic material with a large difference in sound velocity from the piezoelectric layer (12).

7. A method for manufacturing an acoustic atomizing chip according to any one of claims 1-6, characterized in that, include: The mask pattern of the prepared transducer is transferred to the surface of the carrier substrate to form the transducer (2). A protective layer (3) is formed on the non-bonded area of ​​the transducer (2) by sputtering or chemical vapor deposition. The carrier substrate is attached to the carrier film, cut, baked or irradiated with ultraviolet light, and the film is peeled off or separated by a pick-up process to obtain an independent piezoelectric substrate (1). A first receiving hole (11) is processed using a pulsed laser in the region of the piezoelectric substrate (1) corresponding to the aperture range of the transducer (2). A second receiving hole (51) is prepared on the support layer (5) at a position corresponding to the first receiving hole (11); The lower surface of the piezoelectric substrate (1) is bonded to the upper surface of the support layer (5) using a transition connection layer (4); The liquid transfer medium (6) is injected into the area defined by the first receiving hole (11) and the second receiving hole (51) using a pressing process.

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