A transparent array transducer, method of manufacture and photoacoustic probe

Abstract

The present application relates to photoacoustic imaging technical field, specifically to a kind of transparent array transducer, preparation method and photoacoustic probe.The photoacoustic probe includes lens group, transparent array transducer, shell, wire;The lens group is set to the side of the light beam output end of light source, the main optical axis of the lens group is coaxial with the center of the light source;The transparent array transducer is set to the side of the light beam output end of lens group;The shell is set to the side of relatively away from the transparent array transducer and the lens group;The wire is connected on the transparent array transducer and is led out from the shell.The photoacoustic probe provided by the present application makes up the defect that the volume of existing photoacoustic probe is large, and the imaging signal-to-noise ratio and resolution decline caused by existing light, sound coaxial design, realizes seamless integration of optical and ultrasonic imaging in the same probe, improves the compactness and convenience of imaging system, has extensive scientific research value and market potential.

Description

Technical Field

[0001] This invention relates to the field of photoacoustic imaging technology, specifically to a transparent array transducer, its fabrication method, and a photoacoustic probe. Background Technology

[0002] Photoacoustic imaging technology is an emerging imaging technology based on the photoacoustic effect. It combines the advantages of high contrast in optical imaging and deep penetration in acoustic imaging, and has advantages over traditional optical imaging and ultrasound imaging in terms of contrast, imaging depth, resolution and sensitivity.

[0003] Traditional photoacoustic imaging systems achieve photoacoustic coaxial focusing between components such as lasers and transducers through various methods, such as using light windows or glass prisms that can transmit light and reflect sound waves, or couplers made of PMMA that reflect light and transmit sound waves. However, these systems suffer from high complexity, large probe size, and the addition of light-transmitting and sound-reflecting or sound-transmitting and light-reflecting structures between the transducer and the skin, which occupy valuable optimal imaging areas, resulting in poor imaging effects and limited range.

[0004] In existing technologies, optically transparent ultrasonic transducers made from bulk piezoelectric materials can realize more compact, efficient, and versatile photoacoustic imaging systems, directly achieving photoacoustic coaxiality. One technology proposes a transparent transducer based on lithium niobate and its optically high-resolution photoacoustic microscope. The proposed single transducer is easy to manufacture, but it lacks a matching layer and has a low frequency, narrow bandwidth, and poor imaging range and scanning speed. Another technology proposes a transparent linear array transducer that includes a matching layer, but it does not involve a complete photoacoustic probe, resulting in poor photoacoustic signal acquisition capabilities.

[0005] Transparent array transducers simplify the design complexity of optical lenses and photoacoustic coaxial structures, reducing probe size for easier handheld use. Furthermore, this invention avoids introducing structures between the transparent transducer and skin that could degrade image quality, thus improving spatial resolution and signal-to-noise ratio. In addition to photoacoustic imaging, this probe also enables ultrasound multi-beam imaging, variable beam direction, and variable focal length. Currently, there are no photoacoustic probe designs based on transparent array transducers. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a transparent array transducer, its fabrication method, and a photoacoustic probe.

[0007] In a first aspect, the present invention provides a transparent array transducer comprising: a transparent piezoelectric layer array, the transparent piezoelectric layer array comprising a plurality of transparent piezoelectric layers, each of the transparent piezoelectric layers comprising a first surface and an opposing surface of the first surface; transparent electrode layers, the transparent electrode layers respectively located on the first surface and the opposing surface; matching layers, the matching layers respectively located on opposite sides perpendicular to the first surface and the opposing surface; a backing layer, the backing layer located on opposite sides relatively away from the matching layer; and a grounding shell, the grounding shell located on one side relatively away from the transparent piezoelectric layer array, the middle region being completely hollow in a tubular shape from both ends. The present invention, by optimizing the material structure of the transparent piezoelectric layer, transparent electrode layer, matching layer, and backing layer, and precisely controlling the connection quality of each layer's material structure, obtains a transparent array transducer capable of achieving high-quality photoacoustic imaging. The transparent array transducer possesses unique multi-mode imaging capabilities, high definition and high resolution, miniaturization and portability, safety and biocompatibility, and other characteristics, and has broad application prospects in fields such as medical testing and materials analysis.

[0008] Optionally, the transparent array transducer further includes gaps located between adjacent transparent piezoelectric layers, the gaps being filled with epoxy resin. This invention fills the gaps between adjacent transparent piezoelectric layers of the transparent array transducer with epoxy resin, offering significant and multifaceted benefits. First, epoxy resin, as an excellent photoacoustic coupling medium, ensures efficient transmission of photoacoustic signals between the transparent piezoelectric layers, reducing reflection and scattering caused by medium mismatch, thereby improving the transducer's photoacoustic performance. Second, epoxy resin possesses excellent bonding properties, firmly adhering to adjacent transparent piezoelectric layers, enhancing the overall structural strength and stability of the transducer, ensuring excellent performance under various operating environments. Third, epoxy resin also exhibits excellent insulation properties, effectively isolating electrical signal interference between adjacent piezoelectric layers, ensuring stable and reliable electrical performance of the transducer. Fourth, the selection of epoxy resin also considers its temperature resistance and corrosion resistance to adapt to the environmental requirements of different application scenarios. Therefore, the application of epoxy resin in the transparent array transducer plays a crucial role in improving the transducer's photoacoustic performance, structural stability, and electrical performance.

[0009] Secondly, the present invention provides a method for fabricating a transparent array transducer, comprising the following steps: providing a piezoelectric material layer; polishing the piezoelectric material layer on both sides to obtain a transparent piezoelectric layer; cutting the transparent piezoelectric layer to obtain a transparent piezoelectric layer array, wherein the gaps between the transparent piezoelectric layer arrays are filled with epoxy resin; coating indium tin oxide on the first surface and the opposing surface of the transparent piezoelectric layer in the transparent piezoelectric layer array respectively to obtain a transparent electrode layer; mixing silicon dioxide and epoxy resin in different mass percentages to obtain a composite material of silicon dioxide and epoxy resin; and coating the first surface of the transparent piezoelectric layer array with epoxy resin. A transparent piezoelectric layer array with a matching layer is prepared by coating matching materials on opposite sides of the surface perpendicular to the opposite surface; epoxy resin is coated on opposite sides of the transparent piezoelectric layer array that are opposite to the matching layer to prepare a transparent piezoelectric layer array with a backing layer; the transparent electrode layer of the transparent piezoelectric layer array with the backing layer is bonded with flexible wires to prepare a transparent piezoelectric layer array with wires; a brass tube is provided, and the middle part of the brass tube is hollowed out to both ends to prepare a grounding shell; the grounding shell is placed on the side opposite to the transparent piezoelectric layer array with wires and encapsulated to prepare a transparent array transducer. The fabrication method of this invention utilizes the stacking of multiple material layers, resulting in good consistency among array units, thereby reducing costs and improving overall performance. Polishing ensures high optical transparency of the transducer, allowing unobstructed light transmission and further achieving tight integration of optical and ultrasonic imaging. The stacking of multiple material structures enhances the electromechanical coupling coefficient and photoelectric transmission efficiency of the transducer, further improving imaging quality. The transparent array transducer fabricated using this method broadens the application fields of transducers, laying a solid foundation for technological progress and application expansion.

[0010] Optionally, the matching materials include: a matching material for a general matching layer, wherein the general matching layer matching material comprises a composite material of silica and epoxy resin; and a matching material for a waterproof matching layer, wherein the waterproof matching layer matching material comprises parylene. The design of the matching materials in this invention fully considers the needs of different application scenarios, specifically divided into two categories: one is a general matching layer material for ordinary environments, which is ingeniously combined with silica and epoxy resin. The hardness of silica and the adhesiveness of epoxy resin complement each other, jointly giving the composite material excellent matching performance and durability, enabling it to perfectly adapt to various challenges in ordinary working environments. The other category is a waterproof matching layer material specifically designed for waterproof environments, whose main component is parylene. Parylene is known for its excellent waterproof and moisture-proof properties, effectively isolating moisture intrusion and protecting the internal structure from damage. In application scenarios requiring high waterproofing, the waterproof matching layer material, with its excellent performance, ensures the stable operation and long-term use of the transducer. Therefore, through precise material selection and scientific formulation, these two matching materials not only meet the matching requirements of different application scenarios, but also improve the performance stability and service life of the transducer, making them an indispensable and important component in photoacoustic imaging technology.

[0011] Thirdly, the present invention provides a photoacoustic probe comprising a lens group, a transparent array transducer, a housing, and wires; the lens group is disposed at the laser emission end of a light source, and the principal optical axis of the lens group is coaxial with the center of the light source, for shaping the light beam emitted by the photoacoustic signal source; the transparent array transducer is disposed on one side of the light beam emission end of the lens group, for transmitting and receiving the photoacoustic signal emitted by the object under test; the housing is disposed on a side relatively away from the transparent array transducer and the lens group, for allowing the transparent array transducer to stably receive the light beam from the lens group and coaxial with the center of the lens group; the wires are connected to the transparent array transducer and led out from the housing, for receiving and transmitting the photoacoustic signal collected by the transparent array transducer. The photoacoustic probe based on a transparent array transducer provided by this invention exhibits significant effects. This probe integrates a laser adjustment component, a transparent array transducer, and a light-emitting device interface into a single unit, simplifying the photoacoustic coaxial design and reducing the probe's size. By maintaining a constant distance between the light source and the imaging area through a fixed connection, it minimizes the impact of light transmission variations on imaging performance, overcoming the shortcomings of existing photoacoustic probes, such as large size and reduced signal-to-noise ratio and resolution due to existing coaxial optical and acoustic designs. This photoacoustic probe achieves seamless integration of optical and ultrasonic imaging within the same probe, improving the compactness and convenience of the imaging system. It provides rich tissue structure and functional information for photoacoustic imaging and is applicable to fields such as biomedicine, materials science, and non-destructive testing, possessing broad research value and market potential. Furthermore, it promotes the development of multimodal imaging technology, enabling the simultaneous execution and information fusion of multiple imaging technologies such as ultrasound, photoacoustics, and optical coherence tomography, providing more comprehensive and accurate information support for early disease diagnosis and precision treatment.

[0012] Optionally, the lens group includes a convex lens, a concave lens, and a plane lens; the convex lens, the concave lens, and the plane lens are arranged in different combinations for center alignment. The lens group designed in this invention embodies high flexibility and precision. By including one or more freely combinable lenses, it allows for flexible selection of the number, type, and combination of lenses according to specific application scenarios and beam adjustment needs, achieving optimal focusing, diffusion, or correction effects, and further realizing diversified beam adjustment capabilities. The meticulous construction of the lens group integrates the focusing power of a convex lens, the diverging power of a concave lens, and the stabilizing foundation of a plane lens. These three elements are ingeniously arranged in various combinations for center alignment, weaving together a complex yet orderly lens assembly. One end of the lens assembly precisely faces the photoacoustic signal source, like a keen eye capturing every interplay of light and sound; while the other end resolutely faces away from the photoacoustic signal source, guiding the regulated light in a predetermined direction, demonstrating exceptional guiding and transmission capabilities. The ingenious design of the lens assembly lies in its ability to flexibly control the propagation path and characteristics of light, exhibiting superior optical performance. This is not only a crystallization of optical technology, but also a perfect fusion of precision design and innovative thinking.

[0013] Optionally, the lens assembly further includes a support connecting the convex lens, the concave lens, and the plane lens, for supporting the convex lens, the concave lens, and the plane lens, and for flexibly adjusting and fixing the positions of the convex lens, the concave lens, and the plane lens. The lens assembly of this invention not only integrates the diverse functions of convex, concave, and plane lenses, but also cleverly introduces the key component of a support. As the stable foundation of the entire lens assembly, the support not only bears the heavy responsibility of supporting the convex, concave, and plane lenses, ensuring precise alignment and stable connection between the lenses, but also endows the lens assembly with unprecedented flexible adjustment capabilities. Through precise mechanical design, the support can easily achieve fine-tuning and fixing of the positions of each lens, effortlessly handling tasks such as optimizing light paths, adjusting focal length range, or meeting specific optical effect requirements. This design greatly enhances the adaptability and flexibility of the lens assembly, enabling it to demonstrate broad application prospects and excellent performance in multiple fields such as scientific research, industrial inspection, and medical imaging.

[0014] Optionally, the housing includes: a partition plate disposed between the transparent array transducer and the lens; a first housing connected to the partition plate, the first housing containing the transparent array transducer; and a second housing connected to the partition plate, the second housing containing the lens assembly. The design of the housing of this invention fully demonstrates its core role and unique advantages in the photoacoustic signal processing system. By cleverly integrating three key elements—the partition plate, the first housing, and the second housing—the housing constructs an internal space that is both independent and collaborative, achieving efficient processing and precise transmission of photoacoustic signals. The partition plate, as the central hub within the housing, is precisely positioned between the transparent array transducer and the lens assembly, effectively dividing two different working areas, avoiding mutual interference, and ensuring the continuity and stability of the photoacoustic signal during transmission. The robust structure and precise manufacturing process of the first housing provide excellent protection and support for the transducer, and its optimized internal space design allows the transducer to fully utilize its performance advantages, achieving efficient conversion and acquisition of photoacoustic signals. The precise layout and material selection of the second housing's internal space create a stable and pristine working environment for the lens assembly. This not only helps improve the clarity and accuracy of optical imaging but also ensures the stable performance of the lens assembly during long-term use. Therefore, the design of the housing reflects not only a deep understanding and precise control of the internal structure of the photoacoustic signal processing system but also demonstrates exceptional skill in material selection and process design. The ultimate result is the construction of a highly efficient, stable, and reliable photoacoustic signal processing platform, providing strong support for scientific research and technological development in related fields.

[0015] Optionally, the second housing includes: a mounting hole arranged at the center of the second housing; and a connecting component fixed in the mounting hole for connecting the laser output end of the light guide device. The second housing of this invention, as a key component inside the housing, cleverly integrates the mounting hole and the connecting component in its unique structure, further enhancing the integration and functionality of the photoacoustic signal processing system. The mounting hole, carefully arranged at the center of the second housing, is not only precisely positioned but also rationally sized, ensuring that the beam can accurately pass through the mounting hole for further optical processing, thereby guaranteeing the continuity and efficiency of photoacoustic signal conversion and transmission. The connecting component, as a key element in the mounting hole, is made of high-quality material and has a robust structure. Through precise machining and installation, it is firmly fixed in the mounting hole, effectively supporting the beam output end of the light guide device, preventing it from shaking or shifting during operation, and withstanding the heat and stress that may be generated during light transmission, ensuring the long-term stable operation of the system. Simultaneously, the design of the connecting component also considers the need for easy installation and disassembly, providing great convenience for system maintenance and upgrades. Therefore, the ingenious combination of mounting holes and connecting components not only improves the overall performance and stability of the photoacoustic signal processing system, but also achieves efficient connection and precise alignment between the light guide device and the lens assembly. This design achievement not only reflects a deep understanding and precise control of photoacoustic signal processing technology, but also provides important reference and guidance for scientific research and technological development in related fields.

[0016] Optionally, the light guide device corresponding to the light source includes an optical fiber, an optical fiber bundle, an LED, or a light guide arm; one end of the optical fiber is connected to the connecting component, and the other end of the optical fiber is connected to a laser emitting device; or one end of the optical fiber bundle is connected to the connecting component, and the other end of the optical fiber bundle is connected to a laser emitting device; or the output end of the LED light source is connected to the connecting component; or one end of the light guide arm is connected to the connecting component, and the other end of the light guide arm is connected to a laser emitting device. The light guide device corresponding to the light source of the present invention, as a key bridge connecting the beam input end of the lens group and the mounting hole, exhibits excellent optical transmission performance and precise positioning capability; one end is tightly connected to the beam input end of the lens group, accurately providing a beam coaxial with the center of the lens group, ensuring that energy loss and spot distortion of the beam are minimized during transmission. This not only guarantees the purity and stability of the beam but also lays a solid foundation for subsequent photoacoustic signal conversion; the other end is precisely aligned with the mounting hole, efficiently and stably transmitting the received beam to the transparent array transducer. The beam is coaxial with the center of the lens group, achieving seamless transmission and precise positioning of the beam inside the housing. Therefore, the light source plays a crucial role in the photoacoustic signal processing system, not only realizing the precise transmission and positioning of the beam between the lens group and the separator, but also ensuring the optical performance and stability of the entire photoacoustic probe system through optimized design and exquisite craftsmanship. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a transparent linear array transducer according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of a transparent curved surface array transducer according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of a transparent two-dimensional array transducer according to an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the fabrication process of the transparent array transducer according to an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the overall structure of the photoacoustic probe based on a transparent array transducer according to an embodiment of the present invention;

[0022] Figure 6 This is a schematic cross-sectional view of a photoacoustic probe based on a transparent array transducer according to an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures

[0024] 1 is the light source; 2 is the laser; 3 is the lens group; 4 is the housing; 5 is the transparent array transducer; 6 is the wire; 7 is the photoacoustic signal generated by the material; 8 is the object irradiated by the laser; 9 is the specific material inside the object; 10 is the transparent piezoelectric layer array of the transparent linear array transducer; 11 is the transparent piezoelectric layer array of the transparent curved array transducer; 12 is the transparent piezoelectric layer array of the transparent two-dimensional array transducer; 13 is the lens; 14 is the lens mounting bracket; 15 is the housing; 16 is the transparent linear array transducer or the transparent two-dimensional array transducer; 17 is the wire of the transparent linear array transducer or the transparent two-dimensional array transducer; 18 is the transparent two-dimensional array transducer. Detailed Implementation

[0025] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the invention.

[0026] Throughout this specification, references to "an embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale.

[0027] Please see Figure 1 , Figure 2 and Figure 3 , Figure 1 This is a schematic diagram of a transparent linear array transducer according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a transparent curved surface array transducer according to an embodiment of the present invention. Figure 3 This is a schematic diagram of a transparent two-dimensional array transducer according to an embodiment of the present invention. One embodiment of the present invention provides a transparent linear array transducer, such as... Figure 1 As shown, the transparent array transducer includes:

[0028] A transparent piezoelectric layer array 10 is provided, comprising multiple transparent piezoelectric layers, each including a first surface and an opposing surface. In this embodiment, lithium niobate transparent piezoelectric material is used to fabricate the transparent piezoelectric layers. Lithium niobate transparent piezoelectric material has high transparency and good piezoelectric properties, and is widely used in piezoelectric sensors and transducers. The transparent piezoelectric layer is designed as a multilayer structure, with multiple thin films bonded together through a lamination manufacturing process to enhance its piezoelectric properties and mechanical strength.

[0029] A transparent electrode layer is located on both the first surface and the opposite surface. In this embodiment, the transparent electrode layer is made of indium tin oxide (ITO), a material with good conductivity and transparency. ITO exhibits high transparency in the visible light band while maintaining good conductivity. The electrode layer is designed as a sandwich structure deposited on the upper and lower surfaces of the transparent piezoelectric layer. The pattern design of the electrode layer can be customized according to the specific requirements of the transducer to achieve optimal electrical signal transmission and piezoelectric conversion efficiency. The electrode layer serves as the input and output terminals of the electrical signal, and together with the transparent piezoelectric layer, constitutes the core working area of ​​the transducer.

[0030] Matching layers are located on opposite sides perpendicular to the first surface and the opposing surface. In this embodiment, a silica-epoxy resin composite material is used as the matching layer, and parylene is used as the waterproof matching layer. The matching layers are placed between the transparent piezoelectric layer and the external medium of the transducer to reduce signal reflection and scattering losses. The thickness and material of the matching layer can be optimized according to specific application requirements. The matching layer can improve the photoacoustic impedance matching relationship between the transducer and the external environment, and improve the photoacoustic transmission efficiency and transducer performance.

[0031] A backing layer is located on opposite sides of the matching layer. In this embodiment, an epoxy resin material is used as the backing layer. The epoxy resin material can effectively absorb the photoacoustic energy reflected from the back of the piezoelectric layer, reducing unnecessary vibration and interference. The backing layer is placed on the back of the transparent piezoelectric layer and is tightly bonded to it. Its thickness and material can be customized according to the specific needs of the transducer. The backing layer can improve the photoacoustic performance of the transducer and increase the axial resolution and signal-to-noise ratio of the system.

[0032] The grounding shell is located on a side relatively away from the transparent piezoelectric layer array, and its middle region to both ends are completely hollow like a pipe. In this embodiment, the grounding shell is made of brass, a metal material with good conductivity and high mechanical strength. Its middle section is hollowed out to form a brass tube, which provides good electromagnetic shielding and mechanical protection. The grounding shell is designed as a container that tightly encloses the internal structure of the transducer, and its surface can be specially treated to improve corrosion resistance and aesthetics. Conductive connectors are provided inside the grounding shell to achieve signal connection with the electrode layer. The grounding shell protects the internal structure of the transducer from external environmental influences and damage, and provides a signal grounding path to ensure the safe and stable operation of the transducer.

[0033] Please see Figure 4 , Figure 4 A method for fabricating a transparent array transducer according to another embodiment of the present invention includes the following steps:

[0034] A piezoelectric material layer is provided, and the piezoelectric material layer is polished on both sides to prepare a transparent piezoelectric layer. In this embodiment, lithium niobate is selected as the piezoelectric material layer. The lithium niobate is polished on both sides using a polishing machine, and the surface flatness is less than 0.5 μm, and the parallelism between the two surfaces is less than 1 μm.

[0035] The transparent piezoelectric layer is cut to prepare a transparent piezoelectric layer array 10, and the gaps between the transparent piezoelectric layer array 10 are filled with epoxy resin. In this embodiment, the transparent piezoelectric layer array 10 is cut using photolithography, including steps such as coating, exposure, development, and etching. In the design of the transparent piezoelectric layer array 10, the element width is less than 0.6 × (element thickness) and greater than λ / 2 to avoid parasitic resonance modes. The element spacing needs to be in the range of λ / 2 to 3λ / 2 to avoid grating lobes. Here, λ represents the ultrasonic wavelength in the tissue medium.

[0036] Indium tin oxide (ITO) is coated onto the first surface of the transparent piezoelectric layer and its opposing surface in the transparent piezoelectric layer array 10 to prepare a transparent electrode layer. In this embodiment, the ITO electrode layer is prepared by magnetron sputtering at a thickness of 200 nm.

[0037] Silica and epoxy resin were mixed in different mass percentages to prepare composite materials. In this embodiment, 3μm silica particles were mixed into epoxy resin to obtain silica-epoxy resin composite materials with different mass fractions and impedance values, which were then used as matching layer materials.

[0038] A matching material is applied to the opposite sides of the first surface and the opposite surface of the transparent piezoelectric layer array 10, perpendicular to each other, to prepare a transparent piezoelectric layer array 10 with a matching layer. In this embodiment, a composite material of silicon dioxide and epoxy resin is first coated on both sides of the transparent piezoelectric layer array 10 element, and then a waterproof matching material, parylene, is applied to obtain a waterproof transparent piezoelectric layer array 10 with a matching layer.

[0039] Epoxy resin is coated on opposite sides of the matching layer of the transparent piezoelectric layer array 10 to obtain a transparent piezoelectric layer array 10 with a backing layer. In this embodiment, a layer of epoxy resin is uniformly coated on both sides of the transparent piezoelectric layer array 10 with the matching layer. By controlling the coating thickness and uniformity, it is ensured that the epoxy resin layer provides the necessary mechanical support without affecting the light transmittance of the piezoelectric layer. After the epoxy resin cures, a backing layer is formed, resulting in the transparent piezoelectric layer array 10 with a backing layer.

[0040] The electrode layers of the transparent piezoelectric layer array 10 with a backing layer are bonded together using flexible wires to prepare a transparent piezoelectric layer array 10 with wires. In this embodiment, a layer of conductive adhesive is uniformly applied to the backing layer of the transparent piezoelectric layer array 10, and then the flexible wires are precisely attached to the adhesive. The wires are then bonded tightly to the electrode layers by applying pressure or heating. After the adhesive cures, a stable electrical connection is formed, thus preparing the transparent piezoelectric layer array 10 with wires.

[0041] A metal tube is provided, and its middle section is hollowed out to both ends to prepare a grounding shell. In this embodiment, a standard brass tube is selected, and through precision machining, a pipe-like hollowing process is performed in the middle section of the brass tube until evenly distributed holes are formed at both ends, ensuring a stable structure and good conductivity. Subsequently, the hollowed-out areas are polished and cleaned to remove burrs and impurities, finally obtaining the grounding shell as required by the design. This shell can be directly used in a grounding system, providing effective electrical connection and protection.

[0042] The grounded outer shell is placed on one side opposite to the transparent piezoelectric layer array 10 with conductive wires and encapsulated to prepare a transparent array transducer. In this embodiment, the prepared grounded outer shell is placed on the back of the transparent piezoelectric layer array, and high-precision positioning technology is used to ensure that the outer shell is aligned with the piezoelectric layer array. Subsequently, a transparent encapsulation material is used to encapsulate the entire structure, forming a sealed structure that protects the internal components while maintaining light transmittance, ultimately resulting in the transparent array transducer.

[0043] Please see Figure 5 and Figure 6 , Figure 5This is a schematic diagram of the overall structure of a photoacoustic probe based on a transparent array transducer, according to another embodiment of the present invention. Figure 6 This is a cross-sectional schematic diagram of a photoacoustic probe based on a transparent array transducer according to another embodiment of the present invention. The photoacoustic probe mainly includes a lens group 3, a transparent array transducer 5, a housing 15, and wires 6, as shown below. Figure 5 As shown;

[0044] The lens group 3 is disposed at the laser 2 emission end of the light source 1. The principal optical axis of the lens group 3 is coaxial with the central axis of the light source 1, and is used to shape the light beam emitted by the light source 1. In this embodiment, a detailed optical design was carried out based on the characteristics of the light source 1. Through calculation and simulation, the optimal combination of the lens group 3, the radius of curvature, thickness, and spacing between each lens 13 were determined. Next, according to the design scheme, each lens 13 was installed one by one on the lens fixing bracket 14. During the installation process, high-precision positioning and adjustment technology was adopted to ensure that the position and angle of each lens 13 met the design requirements. At the same time, in order to maintain the stability and durability of the lens group 3, the lens group 3 was reliably fixed and encapsulated. When the laser 2 emitted by the light source 1 passes through the lens group 3, after refraction and focusing by multiple lenses 13, the divergence angle of the beam is significantly reduced, the spot size is precisely controlled, and the energy distribution of the beam becomes more uniform. The shaped beam can more effectively excite the acoustic signal in the photoacoustic signal source, thereby improving the sensitivity and resolution of photoacoustic imaging. In addition, lens group 3 also has a certain degree of flexibility and adjustability. By fine-tuning the position and angle of one or more lenses 13 in lens group 3, the focusing depth and illumination range of the beam can be adjusted as needed to adapt to the photoacoustic imaging requirements of different application scenarios.

[0045] The transparent array transducer 5 is disposed on one side of the beam emission end of the lens group, and is used to transmit and receive the photoacoustic signal 7 emitted by the object under test. In this embodiment, a transparent array transducer 5 is cleverly disposed at the beam emission end of the lens group 3, that is, at the position where the beam is about to leave the probe after being shaped by the lens group 3. The transparent array transducer 5 is composed of a series of tiny and highly sensitive piezoelectric elements, which are arranged in an array on a transparent substrate material, and can simultaneously serve as an optical window and a sound receiver. The design of the transparent array transducer 5 fully considers the balance between light transmittance and acoustic sensitivity. Its transparent substrate material has excellent light transmittance, allowing the shaped beam to penetrate and irradiate the object under test without obstruction. At the same time, the piezoelectric elements in the array are responsible for receiving the photoacoustic signal 7 generated by the object under test under the irradiation of the beam. These photoacoustic signals 7 are ultrasonic waves generated by the absorption of light energy and its conversion into heat energy, which in turn induces local thermal expansion of the object. When the light beam illuminates the object under test and generates photoacoustic signals 7, these signals pass through the transparent substrate material of the transparent array transducer 5 and are received by the piezoelectric elements in the array. Upon receiving the acoustic wave vibrations, the piezoelectric elements generate corresponding electrical signal outputs, which are then transmitted to the signal processing system for further analysis and imaging. Through the arrangement of the transparent array transducer 5, the photoacoustic probe can not only achieve precise beam shaping and focusing but also efficiently and sensitively receive the photoacoustic signals 7 emitted by the object under test. This design not only improves the resolution and signal-to-noise ratio of photoacoustic imaging but also enables multi-channel parallel detection, further accelerating the imaging speed and broadening the application areas of photoacoustic imaging.

[0046] The housing 4 is positioned on a side relatively away from the transparent array transducer 5 and the lens group 3, allowing the transparent array transducer 5 to stably receive a light beam from the lens group 3 and coaxial with the center of the lens group 3. In this embodiment, the shape and size of the housing 4 are carefully designed to ensure that it can tightly enclose and fix the internal components of the photoacoustic probe, while leaving necessary openings and channels to allow the light beam and sound waves to pass through. Special attention is paid to the relative positional relationship between the lens group 3 and the transparent array transducer 5 in the layout of the housing 4. The housing 4 is positioned on the relatively opposite side of the transparent array transducer 5 and the lens group 3. This layout effectively avoids interference from the housing 4 on the light beam transmission, ensuring that the light beam emitted by the lens group 3 can pass unobstructed through the openings or transparent windows on the housing 4 and accurately illuminate the transparent array transducer 5. Simultaneously, the housing 4 also provides a stable operating environment for the transparent array transducer 5, reducing the impact of external vibrations and shocks on its receiving performance. To further enhance the receiving stability of the transparent array transducer 5, corresponding support structures and damping materials are also provided inside the housing 4. These support structures can effectively fix the transparent array transducer 5, preventing it from shifting or shaking during operation; while the damping materials can absorb and disperse external vibration energy, protecting internal components from damage. In summary, the housing 4 in this embodiment, through its reasonable layout, robust structure, and meticulous design, provides effective protection and support for the internal components of the photoacoustic probe, ensuring that the transparent array transducer 5 can stably receive the light beam from the lens group 3 and output a high-quality photoacoustic signal 7.

[0047] The wire 6 is connected to the transparent array transducer 5 and leads out from the housing, used to transmit the signal collected by the transparent array transducer 5. In this embodiment, a high-purity, low-impedance copper wire is selected as the signal transmission medium. This wire has good conductivity and anti-interference ability, ensuring high fidelity of the photoacoustic signal 7 during transmission. Dedicated wire connection points are pre-set on the edge or back of the transparent array transducer 5. These connection points are silver-plated to improve conductivity and corrosion resistance. One end of the wire 6 is tightly connected to these connection points through a precision welding or crimping process to ensure reliable signal transmission. Subsequently, the wire 6 is arranged along a pre-set channel inside the housing 4 to avoid interference or friction with other internal components. During the wiring process, special attention is paid to the direction and length of the wire 6 to ensure the shortest signal transmission path and the lowest impedance. At the same time, necessary fixing measures are also adopted to prevent the wire 6 from loosening or shifting during probe operation. When the wire 6 extends from the transparent array transducer 5 and passes through the housing 4, a dedicated wire hole is provided at the corresponding location on the housing 4, and a sealing gasket is fitted to ensure that the sealing performance of the housing 4 is not affected. After passing through the wire hole, the wire 6 is connected to an external signal processing system via an external connector or interface. To ensure the stable transmission of the photoacoustic signal 7, the wire 6 is also shielded as necessary. Differential signal transmission technology or other advanced signal processing technologies are used to further improve the signal's anti-interference capability and transmission quality. In summary, the wire 6 in this embodiment, through its high-quality material selection, precise connection process, reasonable wiring design, and necessary shielding, provides a stable and reliable transmission channel for the photoacoustic signal 7 collected by the transparent array transducer 5 in the photoacoustic probe.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A photoacoustic probe, characterized in that, Includes lens assembly, transparent array transducer, housing, and wires; The lens group is disposed on one side of the beam output end of the light source, and the principal optical axis of the lens group is coaxial with the center of the light source; The transparent array transducer is disposed on one side of the beam output end of the lens group; The housing is located on a side relatively opposite to the transparent array transducer and the lens group; The wires are connected to the transparent array transducer and lead out from the housing; The transparent array transducer includes a transparent piezoelectric layer array, a transparent electrode layer, a matching layer, a backing layer, and a grounded housing; The transparent piezoelectric layer array includes multiple transparent piezoelectric layers, each of which includes a first surface and an opposing surface of the first surface; The transparent electrode layers are located on the first surface and the opposite surface, respectively; The matching layers are located on opposite sides perpendicular to the first surface and the opposite surface, respectively; The backing layer is located on a surface that is relatively opposite to the matching layer; The grounded outer shell is located on a side relatively away from the transparent piezoelectric layer array, and the middle region to both ends is completely hollow in a tubular shape.

2. The photoacoustic probe according to claim 1, characterized in that, The transparent array transducer also includes a gap located between adjacent transparent piezoelectric layers.

3. A photoacoustic probe according to claim 1, characterized in that, The lens group includes a convex lens, a concave lens, and a plane lens; The convex lens, the concave lens, and the planar lens are arranged in different combinations with their centers aligned.

4. A photoacoustic probe according to claim 3, characterized in that, The lens group also includes: A support, which connects the convex lens, the concave lens, and the planar lens.

5. A photoacoustic probe according to claim 1, characterized in that, The housing includes: A separator plate is disposed between the transparent array transducer and the lens group; A first housing, the first housing being connected to the partition plate, the first housing containing the transparent array transducer; A second housing is connected to the partition plate, and the lens assembly is contained inside the second housing.

6. A photoacoustic probe according to claim 5, characterized in that, The second housing includes: Mounting holes are arranged at the center of the second housing; A connecting component, which is fixed in the mounting hole, is used to connect the light guide device and the lens group input end corresponding to the light source.

7. A photoacoustic probe according to claim 6, characterized in that, The light guiding device corresponding to the light source includes optical fiber, optical fiber bundle, LED or light guide arm; One end of the optical fiber is connected to the connecting component, and the other end of the optical fiber is connected to the laser emitting device; or one end of the optical fiber bundle is connected to the connecting component, and the other end of the optical fiber bundle is connected to the laser emitting device; or the output end of the LED light source is connected to the connecting component; or one end of the light guide arm is connected to the connecting component, and the other end of the light guide arm is connected to the laser emitting device.

Images