Liquid metal light-induced ultrasonic structure sound wave regulation and control device and use method thereof

Abstract

The invention belongs to the technical field of sound wave regulation and control, and particularly relates to a liquid metal light-induced ultrasonic structure sound wave regulation and control device and a using method thereof. The device comprises a substrate, a photoinduced ultrasonic layer and a laser irradiation system, the photoinduced ultrasonic layer is arranged on the substrate, is doped with liquid metal particles, and can generate expansion under laser irradiation and excite sound waves; the laser irradiation system can sequentially irradiate laser to different positions of the photoinduced ultrasonic layer to excite the sound wave source, and sound waves generated by irradiating the different positions with the laser for multiple times are superposed at a certain position in the space to form sound field regulation and control. According to the laser technology, the sound wave source can be rapidly generated, the sound field regulation and control effect is optimized at different spatial positions and time intervals, higher precision, flexibility and efficiency are achieved, and the method can be widely applied to the field of precise sound wave regulation and control and has good application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of sound wave regulation, and in particular relates to a liquid metal photo-induced ultrasonic structure sound wave regulation device and a use method thereof. Background Art

[0002] With the continuous development of ultrasonic technology, acoustic wave control technology plays an increasingly important role in various types of high-precision equipment. Especially in the fields of medical imaging, industrial detection, ultrasonic imaging, material processing, etc., the focusing and control of acoustic waves have become key technologies for improving equipment performance, improving precision, and reducing losses. Traditional acoustic wave control methods usually rely on physical deformation of mechanical structures (Micromachines 15, no. 9 (2024): 1106.) or electrostrictive technology (AdvancedScience, 11, 15, (2024): 2303403). Although these technologies can control the sound field to a certain extent, their structures are complex, their response speed is slow, and their control accuracy is limited, which cannot meet the growing demand for high precision and high efficiency. Summary of the invention

[0003] To solve the above problems, on the one hand, the present invention provides a liquid metal photoultrasonic structure sound wave control device, including a substrate, a photoultrasonic layer, and a laser irradiation system; the photoultrasonic layer is placed on the substrate and is doped with liquid metal particles, which can expand and stimulate sound waves under laser irradiation; the laser irradiation system can irradiate the laser to different positions of the photoultrasonic layer in turn to stimulate the sound wave source, and the sound waves generated by multiple laser irradiations at different positions are superimposed somewhere in space to form sound field control.

[0004] The present invention adopts a photo-induced ultrasound layer doped with liquid metal particles. The liquid metal generates heat under laser irradiation, so that the photo-induced ultrasound layer can quickly respond to laser irradiation to expand and excite sound waves. The introduction of liquid metal particles improves the absorption efficiency of the photo-induced ultrasound layer to laser energy, and can produce a strong expansion effect in a short time, thereby achieving stronger and more controllable sound wave excitation. This greatly shortens the response time of the sound wave source, and can quickly and accurately control the sound field. Compared with the traditional electrostrictive technology, the present invention realizes the precise excitation of the sound wave source through laser irradiation, and can flexibly adjust the position, shape and time interval of laser irradiation. Laser irradiation not only has a fast response speed, but also has high precision, and can achieve a sound wave control effect far higher than that of electrostrictive technology. Electrostrictive technology needs to rely on the physical movement or deformation of the electrode, and realizes the regulation of the sound wave by changing the electric field effect of the electrode. Such technology has great limitations in response speed, flexibility and control accuracy. The present invention can quickly and accurately generate a sound wave source through precise laser irradiation, and control the sound field by optimizing the time interval and laser irradiation position.

[0005] Furthermore, the liquid metal is gallium-based liquid metal.

[0006] Furthermore, the liquid metal particles are coated with a sodium alginate coating.

[0007] Furthermore, the material of the substrate is quartz glass, soda-lime glass or polycarbonate. These materials have high transparency. During the laser irradiation of the photo-induced ultrasound layer, the light beam can pass through such a substrate to reach the photo-induced ultrasound layer to excite the sound wave, thereby ensuring the efficiency of the laser irradiation and the effect of the sound field regulation. In addition, these materials also have good mechanical strength and will not be deformed or damaged during the laser irradiation and sound wave excitation process.

[0008] On the other hand, the present application provides a method for using a liquid metal photo-induced ultrasonic structure acoustic wave control device, comprising the following steps: Step 1, irradiating the outermost position of the photo-induced ultrasound layer with laser to excite the outermost acoustic wave source; Step 2: after time interval t1, the laser irradiates the inner layer of the photo-induced ultrasound layer to excite the second sound wave source; Step 3: after time interval t2, the laser irradiates a position closer to the center of the photo-induced ultrasound layer to excite the third sound wave source; Step 4, repeating step 3, irradiating the photo-induced ultrasound layer with laser light closer to the center to excite the innermost acoustic wave source; Step 5: By controlling the excitation time of each sound wave source, the sound waves excited from different positions arrive at the predetermined spatial position at the same time, thereby forming a focusing effect at the position.

[0009] Furthermore, the time interval t n Calculated by the following formula: t n = (d n -d0) / v s Among them, d n is the distance from the nth laser irradiation position to the focal point, d0 is the distance from the center of the photo-induced ultrasound layer to the focal point, v s is the propagation speed of sound waves in the medium, t n For the time interval.

[0010] Furthermore, the substrate is a transparent material, and the laser irradiates the photo-induced ultrasound layer from one side of the substrate.

[0011] Furthermore, the outermost sound wave source and other sound wave sources are annular areas, and the innermost sound wave source is a circular area.

[0012] Furthermore, gaps are provided between each acoustic wave source. When multiple acoustic wave sources are very close, the heat generated by the acoustic wave sources will accumulate with each other, causing local high temperature and thermal stress, thereby affecting the stability of the acoustic wave sources. The design of the gap reduces the thermal effect caused by the acoustic wave sources being too dense, helps to maintain the stability of the system, reduces the impact of temperature fluctuations on the acoustic wave sources, and improves the reliability and long-term stability of the entire device. In addition, the close arrangement between the acoustic wave sources leads to several types of mechanical stress, especially in the case of high-power laser irradiation or acoustic wave generation, resulting in uneven thermal expansion or physical damage between adjacent acoustic wave sources. The gap can disperse these stresses, reduce the interaction between adjacent acoustic wave sources, and enhance the durability and long-term stability of the system.

[0013] Furthermore, carbon fiber composite materials, foamed metal or graphene are provided in the gap. Materials such as carbon fiber composite materials, foamed metal and graphene have strong sound wave absorption capabilities, can absorb part of the energy of sound waves, reduce the reflection or unnecessary propagation of sound waves in space, reduce interference or confusion caused by reflection, help control and optimize the distribution of the sound field, make the sound wave energy better focused and propagated in a predetermined area, and improve the accuracy and efficiency of sound wave focusing. In addition, these materials have good thermal conductivity and thermal management performance. Filling the gap with these materials with good thermal conductivity can effectively dissipate heat and prevent local overheating or heat accumulation from causing performance degradation of the sound wave source.

[0014] Beneficial effects of the present invention: The present invention uses liquid metal particles to improve the absorption efficiency of the photo-ultrasound layer for laser energy, making the acoustic wave excitation more rapid and intense, thereby shortening the response time of the acoustic wave source. Compared with the traditional electrostrictive technology, the present invention achieves higher precision and faster response acoustic wave control through laser irradiation, and the flexibility of the laser allows the excitation position, shape and time interval to be precisely adjusted. The electrostrictive technology relies on the physical movement of the electrode and has limitations in response speed and accuracy, while the laser technology of the present invention can quickly generate an acoustic wave source and optimize the acoustic field control effect at different spatial positions and time intervals, with higher precision, flexibility and efficiency. This technology can be widely used in the field of precision acoustic wave control and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of a liquid metal photo-ultrasonic structure acoustic wave control device.

[0016] Figure 2 A schematic diagram of the laser irradiation area of ​​a photo-induced ultrasonic structure that realizes the focusing function.

[0017] In the figure: 1, substrate; 2, photo-induced ultrasound layer; 3, laser irradiation system; 21, first sound wave source; 22, second sound wave source; 23, third sound wave source.

[0018] Figure 3 Optical microscope image of the liquid metal photo-induced ultrasound layer. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0020] Example 1 The present invention provides a liquid metal photo-induced ultrasonic structure acoustic wave control device, such as Figure 1 As shown, it includes a substrate 1, a photo-induced ultrasound layer 2 and a laser irradiation system 3, and the specific design is as follows: (1) Substrate 1: The substrate 1 is a transparent material, and quartz glass is selected, which has high light transmittance and good mechanical strength, and is resistant to high temperatures, and is suitable for the requirement of laser irradiation of the photo-induced ultrasound layer 2 from one side of the substrate 1.

[0021] (2) Photo-induced ultrasound layer 2: The photo-induced ultrasound layer 2 is placed on the substrate 1, made of a polymer composite material, and uniformly doped with gallium-based liquid metal particles. The outer surface of the gallium-based liquid metal particles is coated with a layer of sodium alginate coating to enhance the stability of the particles and prevent oxidation. Under laser irradiation, the liquid metal particles in the photo-induced ultrasound layer 2 absorb light energy, causing the photo-induced ultrasound layer 2 to expand rapidly and generate sound waves. The photo-induced ultrasound layer 2 is designed to be a central area and multiple annular areas. The laser irradiation system 3 irradiates each annular area inward from the outermost annular area in turn, and finally irradiates the central area. Through the laser irradiation sequence of "first the periphery, then the center", it is ensured that the sound waves can arrive at the target focal point synchronously after propagating from different sound wave sources. Among them, the outermost sound wave source is located at the outermost periphery of the photo-induced ultrasound layer 2, which is the first annular area, and the other annular areas are gradually arranged inward. The innermost sound wave source is located at the center of the photo-induced ultrasound layer 2. In order to reduce the mutual interference between different sound wave sources, a gap is set between each sound wave source. Furthermore, the gap is filled with foam metal material. The porous structure of the foam metal can effectively absorb excess sound wave energy, reduce sound wave reflection and interference between sound wave sources, and improve the directionality of sound wave propagation. The foam metal also has good thermal conductivity, can quickly dissipate heat, prevent local heat accumulation caused by laser irradiation and sound wave excitation, and improve the overall operating stability and performance of the device. Preferably, the height of the filled foam metal is greater than the sound wave source. The foam metal forms a physical barrier that effectively isolates the lateral sound wave propagation between adjacent sound wave sources, reduces interference and reflection, and improves the accuracy of sound wave focusing. In addition, the higher foam metal structure increases its surface area and thermal convection capacity, which can significantly improve the heat dissipation performance and avoid local overheating caused by long-term laser irradiation. In addition, when the height of the foam metal exceeds the sound wave source, its wave absorption performance can be further enhanced, effectively absorbing excess sound wave energy, thereby optimizing the sound field distribution and making the sound wave energy at the focal point more concentrated and uniform.

[0022] (3) Laser irradiation system 3: The laser irradiation system 3 uses a controllable laser scanning device, which can sequentially irradiate different areas of the photo-induced ultrasound layer 2. The pulse width, power and time interval of the laser can be precisely controlled to excite the acoustic wave sources at different positions and ensure that the acoustic wave sources are superimposed at the focal point of the target space. Specifically, the laser irradiation system 3 includes a laser light source, an optical control unit, a laser scanner, a control and drive unit, etc. The laser light source is a pulsed laser or a continuous laser with a wavelength of 1064 nanometers or 532 nanometers and adjustable power. The optical control unit includes a lens system, a beam shaper and an optical path control device. The lens system is used to focus the laser to the target area of ​​the photo-induced ultrasound layer 2. The beam shaper is used to shape the laser spot into a variety of shapes (such as a circle or annular) to match the distribution design of the acoustic wave source. The optical path controller includes a reflector and an optical path switching device to guide the laser to different target areas. The laser scanner includes a galvanometer scanning system and an electrically controlled turntable. The galvanometer scanning system includes two reflectors, which respectively control the X-axis and Y-axis directions of the laser. The response speed of the galvanometer scanning system is at the kHz level, and the laser irradiation position can be quickly switched. The scanning resolution is at the micron level, and the designated position of the photo-ultrasound layer 2 can be accurately irradiated. The electrically controlled turntable is used to rotate or move the entire optical path to achieve coverage of the photo-ultrasound layer 2 in a larger range. The control and drive unit includes a time control module, a scanning control module, and a power adjustment module. The time control module is used to accurately control the emission timing of the laser pulse. The scanning control module cooperates with the galvanometer scanning system to control the laser irradiation position and sequence, and inputs the preset irradiation path and time interval into the scanning control module to achieve sequential control of multi-point irradiation. The power adjustment module dynamically adjusts the laser output power according to the response characteristics of different photo-ultrasound layer 2 regions to optimize the acoustic wave excitation effect.

[0023] Preferably, in the photo-induced ultrasound layer 2, the width design of each sound wave source should follow the principle of gradually decreasing from the periphery to the center to optimize the superposition effect of sound waves at the focal point. Since the peripheral sound wave source is far away from the focal point, the sound wave has more energy dispersion during propagation, so the width should be relatively large to enhance the emission intensity and compensate for energy attenuation. The sound wave source near the center is closer to the focal point, has less energy dispersion, and the width should be appropriately reduced to avoid the sound field at the focal point from being too concentrated and causing unevenness. The gradually reduced width distribution can better balance the energy output of the sound wave source, make the sound wave intensity at the focal point more uniform, and reduce the interference between adjacent sound wave sources, thereby achieving more accurate sound field control.

[0024] Example 2 The present invention provides a specific use step of a liquid metal photo-ultrasonic structure acoustic wave control device, and combines the focus point with the center of the photo-ultrasonic layer 2 d0 = 1 meter, the sound speed in the air is v s=343 m / s and the photo-induced ultrasound layer 2 contains three sound wave sources (i.e. Figure 2 The first sound wave source, the second sound wave source, and the third sound wave source in the figure are used to illustrate: Step 1: Laser irradiates the first sound wave source 21 (the outermost area). The first sound wave source 21 is a ring-shaped area with an inner diameter of 15 mm and an outer diameter of 20 mm. The time for the sound wave in this area to propagate to the focal point is: Step 2: Laser irradiates the second sound wave source 22 (middle area). The second sound wave source 22 is a ring-shaped area with an inner diameter of 10 mm and an outer diameter of 14 mm. After irradiating the middle annular area, the time it takes for the sound wave in this area to propagate to the focal point is: Step 3: Laser irradiation of the third sound wave source (central area). The third sound wave source 23 is a circular area with a diameter of 5 mm. The laser is The time it takes for the sound wave in the center of the middle annular area of ​​the post-irradiation to propagate to the focal point is: This embodiment realizes the synchronous superposition of sound waves at the focal point and the formation of a high-intensity focused sound field through the laser irradiation strategy of "first the periphery, then the center" combined with the control of time interval and space.

[0025] Preferably, the surface of the sound wave source of the photo-induced ultrasound layer 2 is designed as a convex structure to optimize the propagation path and focusing performance of the sound wave. Specifically, the central sound wave source is designed as a convex structure with a smaller curvature, and the peripheral sound wave source is designed as a ring-shaped convex surface with a larger curvature to enhance the divergence characteristics of the sound wave. The convex design can guide the sound waves to diverge naturally in space, reduce the interference between the sound wave sources, and optimize the energy distribution of the sound waves, so that the sound waves emitted by each sound wave source can be more efficiently superimposed at the focal point. In addition, the convex structure can also improve the adaptability of the laser incident angle, enhance the absorption efficiency of the photo-induced ultrasound layer 2 to the laser energy, and further improve the excitation intensity of the sound wave.

[0026] Preferably, the focusing effect of the acoustic wave is improved by adjusting the thickness of the photo-induced ultrasound layer 2. Specifically, the thickness of the photo-induced ultrasound layer 2 gradually increases from the central area to the peripheral area. The thinner central area can reduce the intensity of acoustic wave excitation, thereby avoiding the uneven sound field at the focal point caused by excessive enhancement of the close-range acoustic wave source; while the thicker peripheral area can enhance the intensity of acoustic wave excitation and compensate for the attenuation of long-distance acoustic waves due to energy dispersion during propagation. Such a thickness gradient design can balance the energy output of the acoustic wave source, so that the acoustic waves excited by different acoustic wave sources can achieve synchronous superposition with consistent intensity at the focal point, significantly improving the focusing accuracy and uniformity.

[0027] Example 3 The present invention provides a liquid metal photo-induced ultrasonic structure acoustic wave control device, wherein the polymer composite material of the photo-induced ultrasonic layer 2 is a transparent elastomer PDMS (polydimethylsiloxane), and the liquid metal is a gallium indium tin alloy Ga 67 In 20.5 Sn 12.5 The liquid metal particles are doped into the PDMS by first mixing and then dispersing, and then the photoinduced ultrasound layer 2 is obtained through a curing step.

[0028] Specifically, the liquid metal particles and the polymer composite material are prepared respectively by the following steps: First, gallium, indium and tin metal particles were mixed in a mass ratio of 67:20.5:12.5 and stirred for 10 minutes using a mixer. Then, the mixture was heated to 100°C under nitrogen protection, kept for 12 hours and then naturally cooled to room temperature to obtain Ga 67 In 20.5 Sn 12.5 alloy.

[0029] Then, weigh a certain amount of Ga 67 In 20.5 Sn 12.5 The alloy was placed in a PDMS solution (10 mL), and a curing agent (1 mL) was added, with the ratio of curing agent to PDMS being 10:1. The mixed solution was then stirred. 67 In 20.5 Sn 12.5 The mass fraction of the alloy in the PDMS mixed solution is 10%.

[0030] Finally, the PDMS / Ga 67 In 20.5 Sn 12.5 The mixed solution was shaken, mixed and dispersed for 10 minutes, and then the mixed solution was spin-coated (or scraped onto the substrate) and cured at 100° C. for 3 hours, thereby preparing the photoinduced ultrasound layer 2.

[0031] Preferably, the method for preparing liquid metal provided by the present invention changes the concentration of liquid metal particle doping by adjusting the mass fraction of the liquid metal and polymer mixed solution.

[0032] Specifically, by controlling the mass fraction of liquid metal from 1% to 60%, the concentration gradient of the liquid metal particles in the polymer can be regulated. For example, when the mass of the doped liquid metal is constant, in the plane coordinates, the concentration gradient of the liquid metal particles in the photo-induced ultrasound layer 2 presents a circular diffusion gradient from the center to the edge. In the vertical coordinates, the liquid metal in the photo-induced ultrasound layer 2 forms a concentration gradient from top to bottom due to gravity sedimentation. Therefore, by controlling the mass fraction of the doped liquid metal, the concentration gradient distribution pattern of the liquid metal particles in the plane dimension and the vertical dimension can be accurately adjusted to achieve the adjustment of the Young's modulus of the photo-induced ultrasound layer, the liquid metal particle distribution gradient and the acoustic refractive index, and thus more accurately control the effect of ultrasonic focusing.

[0033] Figure 3 This is an optical image taken by an optical microscope when the mass fraction of liquid metal is 10%. Figure 3 a is the liquid metal particle distribution image in the central area, Figure 3 b is the distribution image of liquid metal particles in the edge area. It can be seen that the liquid metal particles in the central area are more concentrated, while the liquid metal particles in the edge area are more sparse.

[0034] The present invention provides a liquid metal photo-ultrasonic structure sound wave control device and a method for using the same. By doping liquid metal particles in the photo-ultrasonic layer 2, the absorption efficiency of laser energy is greatly improved, so that the photo-ultrasonic layer 2 quickly expands and excites sound waves under laser irradiation, thereby achieving rapid response and efficient excitation of the sound wave source. Compared with the traditional electrostrictive technology, the present invention uses laser irradiation to replace the deformation control of the electrode, which not only eliminates the dependence on electric field regulation, but also significantly improves the flexibility, response speed and accuracy of sound wave regulation. The position, shape and time interval of laser irradiation can be flexibly adjusted, and the sound field distribution can be efficiently and accurately controlled to meet diverse application requirements. The present invention breaks through the limitations of traditional sound wave control technology and provides a high-performance solution for fields such as ultrasonic imaging, precision machining and sound field control.

[0035] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A liquid metal photo-ultrasonic structure acoustic wave control device, characterized in that: The invention comprises a substrate, a photo-induced ultrasound layer and a laser irradiation system; the photo-induced ultrasound layer is placed on the substrate and doped with liquid metal particles, which can expand and stimulate sound waves under laser irradiation; the laser irradiation system can sequentially irradiate lasers to different positions of the photo-induced ultrasound layer to stimulate the sound wave source, and the sound waves generated by multiple laser irradiations at different positions are superimposed somewhere in space to form sound field regulation.

2. The liquid metal photo-induced ultrasonic structure acoustic wave control device according to claim 1, characterized in that: The liquid metal is gallium-based liquid metal.

3. The liquid metal photo-induced ultrasonic structure acoustic wave control device according to claim 2, characterized in that: The liquid metal particles are coated with a sodium alginate coating.

4. The liquid metal photo-induced ultrasonic structure acoustic wave control device according to claim 3, characterized in that: The substrate is made of quartz glass, soda-lime glass or polycarbonate.

5. A method for using a liquid metal photo-ultrasonic structure acoustic wave control device, characterized in that: The steps include: Step 1, irradiating the outermost position of the photo-induced ultrasound layer with laser to excite the outermost acoustic wave source; Step 2: after time interval t1, the laser irradiates the inner layer of the photo-induced ultrasound layer to excite the second sound wave source; Step 3: after time interval t2, the laser irradiates a position closer to the center of the photo-induced ultrasound layer to excite the third sound wave source; Step 4, repeating step 3, irradiating the photo-induced ultrasound layer with laser light closer to the center to excite the innermost acoustic wave source; Step 5: By controlling the excitation time of each sound wave source, the sound waves excited from different positions arrive at the predetermined spatial position at the same time, thereby forming a focusing effect at the position.

6. The method for using the liquid metal photo-induced ultrasonic structure acoustic wave control device according to claim 5, characterized in that: Time interval t n Calculated by the following formula: t n = (d n - d0) / v s Among them, d n is the distance from the nth laser irradiation position to the focal point, d0 is the distance from the center of the photo-induced ultrasound layer to the focal point, v s is the propagation speed of sound waves in the medium, t n is the time interval.

7. The method for using the liquid metal photo-ultrasonic structure acoustic wave control device according to claim 6, characterized in that: The substrate is made of transparent material, and the laser irradiates the photo-induced ultrasound layer from one side of the substrate.

8. The method for using the liquid metal photo-induced ultrasonic structure acoustic wave control device according to claim 6, characterized in that: The outermost sound wave source and other sound wave sources are annular areas, and the innermost sound wave source is a circular area.

9. The method for using the liquid metal photo-ultrasonic structure acoustic wave control device according to claim 8, characterized in that: Gaps are provided between the sound wave sources.

10. The method for using the liquid metal photo-ultrasonic structure acoustic wave control device according to claim 9, characterized in that: Carbon fiber composite material, foam metal or graphene is arranged in the gap.

Images