Acoustic field assisted volumetric additive manufacturing apparatus and method

Abstract

The application provides a sound field assisted volume additive manufacturing device and method, which comprises a printing container for containing light-cured printing material and having a bottom boundary made of sound permeable material; first and second sound field generating assemblies arranged at two axial ends of the printing container to form a sound standing wave field; a distance adjusting mechanism for adjusting the effective acoustic distance between the two sound field generating assemblies; a sound impedance matching structure comprising an acoustic communication part for eliminating the air gap between the first sound field generating assembly and the printing material; and a rotating projection curing assembly for driving the printing container to rotate and projecting multi-angle projection patterns to realize volume light-cured forming. The application realizes high-precision controllable arrangement and stable curing forming of the added materials in the printing process.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and more specifically, to a sound field-assisted volumetric additive manufacturing apparatus and method. Background Technology

[0002] Volumetric additive manufacturing (VAM) is a type of additive manufacturing method that uses multi-angle projected light to accumulate a three-dimensional light dose distribution within a rotating transparent container, enabling photosensitive materials to rapidly solidify and form within a volume. Compared to layer-by-layer printing, VAM offers advantages such as faster forming speed, fewer layer defects, and the ability to fabricate soft or biological structures. In recent years, it has attracted attention in the fields of photocurable resins, bio-inks, soft materials, and functional composite materials manufacturing.

[0003] In printing materials containing particles, fibers, cells, or other functional additives, the spatial distribution of these additives directly affects the mechanical, electrical, optical, biological, and anisotropic properties of the printed parts. However, in existing volumetric additive manufacturing processes, the printing container typically needs to be continuously rotated. The additives inside the material are easily affected by gravitational settling, rotational disturbances, viscosity differences, and photocuring shrinkage, resulting in random or uneven distribution. This makes it difficult to form a stable and controllable ordered structure before or during printing.

[0004] Ultrasonic standing waves can generate acoustic radiation forces in liquid or gel precursors, causing suspended particles, fibers, or cells to migrate towards acoustic pressure nodes or antinodes, thereby forming layered, banded, or periodic arrangements. If ultrasonic standing wave manipulation can be coupled with the projection rotational forming process of volumetric additive manufacturing, it is hoped that the controllable arrangement of additives within the printed material can be achieved while maintaining the advantages of rapid volumetric forming. However, integration challenges exist between the ultrasonic transducer, the rotating transparent container, the refractive index matching liquid tank, and the projection optical path, including mechanical connections, sealing, acoustic coupling, optical matching, and synchronous control.

[0005] Therefore, it is necessary to provide a printing apparatus and method capable of ultrasonically assisted arrangement of additives within materials during volumetric additive manufacturing, in order to improve the volumetric printing quality of functional composite materials, biomaterials, and materials containing reinforcing phases. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a sound field-assisted volumetric additive manufacturing apparatus and method.

[0007] A sound field-assisted volumetric additive manufacturing apparatus according to the present invention includes: A printing container for holding photocurable printing material, wherein the bottom boundary of the printing container is made of sound-permeable material; The first sound field generating component and the second sound field generating component are respectively disposed at both ends of the printing container along the axial direction, for forming a standing wave field within the printing container; A spacing adjustment mechanism, connected to the first sound field generating component and / or the second sound field generating component, is used to adjust the effective acoustic distance between the first sound field generating component and the second sound field generating component; An acoustic impedance matching structure includes an acoustic communication portion disposed between the emitting end of the first sound field generating component and the photocurable printing material, the acoustic communication portion being used to eliminate the air gap between the first sound field generating component and the photocurable printing material; A rotating projection curing assembly is used to drive the printing container to rotate around its own axis and project multi-angle projection patterns onto the rotating printing container so that the photocurable printing material undergoes volumetric photocuring.

[0008] Preferably, the acoustic communication portion is used to immerse the end face portion of the emitting end of the first sound field generating component in the photocurable printing material; The acoustic impedance of the sound-transparent material is lower than a preset impedance threshold to reduce the interface reflection loss of sound waves at the bottom boundary of the printing container.

[0009] Preferably, the first sound field generating component includes a support plate, a first ultrasonic transducer, and a mounting cavity; The mounting cavity is sealed to the upper end of the printing container by a sealing gasket. The mounting cavity serves as an injection port for the photocurable printing material and an acoustic coupling cavity. At least a portion of the end face of the transmitting end of the first ultrasonic transducer is immersed in the photocurable printing material within the mounting cavity or the printing container; The sound-permeable material includes at least one of silicone, polydimethylsiloxane, thermoplastic polyurethane, or flexible resin.

[0010] Preferably, the spacing adjustment mechanism is used to drive the first sound field generating component and / or the second sound field generating component to move along the axial direction of the printing container to change the effective acoustic distance; The effective acoustic distance satisfies the relationship of an integer multiple or a half-integer multiple of the acoustic wavelength in the photocurable printing material, so as to form the acoustic standing wave field distributed along the axis within the printing container.

[0011] Preferably, the rotating projection curing assembly includes a hollow rotating motor and a self-centering clamping mechanism; The hollow rotary motor is connected to the self-centering clamping mechanism via a connector. The self-centering clamping mechanism is used to clamp the printing container and keep the axis of the printing container coaxial with the axis of rotation of the hollow rotary motor.

[0012] Preferably, it also includes a refractive index matching container and a temperature control unit; The printing container is at least partially placed inside the refractive index matching container, which is used to contain a refractive index matching liquid to reduce the refraction error of the projected light at the interface between the printing container, the photocurable printing material and the external medium. The temperature regulation unit is located on the outside of the printing container and is used to regulate the temperature of the printing area.

[0013] A sound field-assisted volumetric additive manufacturing method according to the present invention includes: Step S1: Inject a photocurable printing material containing additives into the printing container, and make the emitting end of the first sound field generating component acoustically connected to the photocurable printing material through the acoustic impedance matching structure; Step S2: Activate the first sound field generating component and the second sound field generating component, and adjust the effective acoustic distance through the spacing adjustment mechanism to form the acoustic standing wave field in the printing container, so that the additives form a preset arrangement; Step S3: When the additives form the preset arrangement, start the rotating projection curing component to synchronize the projection sequence of the multi-angle projection pattern with the rotation angle of the printing container, so as to accumulate a three-dimensional light dose distribution in the photocurable printing material and complete the volumetric photocurable printing.

[0014] Preferably, adjusting the effective acoustic distance through the spacing adjustment mechanism to form the acoustic standing wave field within the printing container includes: Adjust the axial distance between the first sound field generating component and the second sound field generating component so that the effective acoustic distance meets the formation conditions of the acoustic standing wave field; Based on the target arrangement of the additives, the operating frequency, output power, or phase difference of the first sound field generating component and / or the second sound field generating component are dynamically adjusted.

[0015] Preferably, before activating the rotary projection curing assembly, the method further includes: The image acquisition unit acquires an image of the arrangement of the additives inside the printing container. Based on the arrangement state image, the arrangement features are extracted, and it is determined whether the arrangement features meet the preset arrangement threshold. If the conditions are not met, the sound field parameters of the first sound field generating component and the second sound field generating component are adjusted in response to feedback until the arrangement feature meets the preset arrangement threshold.

[0016] Preferably, the rotating projection curing assembly includes a projection light source module and a rotating drive mechanism; The step of synchronizing the projection sequence of the multi-angle projection pattern with the rotation angle of the printing container includes: Based on the 3D model to be printed, a projection sequence of the multi-angle projection pattern is generated through Laden transform, filtered back projection, or iterative optimization algorithm. The projection light source module is controlled to output the multi-angle projection pattern according to the projection sequence, and the rotation drive mechanism is controlled to drive the printing container to rotate at a preset angular velocity, so that the projection angle of the multi-angle projection pattern corresponds to the real-time rotation angle of the printing container.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This application optimizes the acoustic transmission path from both the sound source end and the boundary end by setting an acoustic impedance matching structure, using an acoustic connection part to eliminate the air gap between the emitting end of the first sound field generating component and the photocurable printing material, and combining the acoustically transparent material design of the bottom boundary of the printing container. This effectively reduces the reflection loss and energy attenuation of sound waves at the heterogeneous interface, thereby ensuring that a high-intensity and stable acoustic standing wave field can be established in the complex coupling environment of volumetric additive manufacturing.

[0018] 2. This application dynamically adjusts the effective acoustic distance between the first sound field generating component and the second sound field generating component through a spacing adjustment mechanism, so as to adapt to the standing wave formation conditions under different printing materials sound velocities and container sizes. This solves the problem that fixed acoustic cavities are difficult to be compatible with multi-material systems and variable-scale printing process adaptability, so that the node or antinode position of the acoustic standing wave field can be accurately matched with the preset additive arrangement requirements, significantly improving the manufacturing flexibility of functionally graded materials or anisotropic structures.

[0019] 3. This application integrates the sound field control system with the rotary projection curing component at the system level. While maintaining the rotation of the printing container to achieve volumetric photocuring, it uses a self-centering clamping and coaxial drive mechanism to suppress the disturbance of mechanical eccentricity on the stability of the sound field. Combined with the refractive index matching and temperature adjustment unit, it eliminates optical distortion and thermal effect interference, realizing the coordinated operation of sound field induced arrangement and photocuring in the spatiotemporal dimension. This effectively overcomes the defect of uneven distribution of additives in traditional methods due to the influence of rotational centrifugal force and gravity. Attached Figure Description

[0020] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the overall structure of the sound field-assisted volumetric additive manufacturing apparatus according to an embodiment of this application; Figure 2 This is a schematic diagram of the rotating clamping module structure according to an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the first transducer module according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the second transducer module according to an embodiment of this application; Figure 5 This is a schematic diagram of the printing container structure according to an embodiment of this application; Figure 6 This is a schematic diagram illustrating the ultrasonic-assisted volumetric additive manufacturing printing principle of an embodiment of this application; Figure 7 This is a flowchart of an ultrasonic-assisted volumetric additive manufacturing printing method according to an embodiment of this application.

[0021] Explanation of reference numerals in the attached drawings: 1. Projector; 2. Scissor lift platform; 3. Camera module; 4. Cooling water tank; 5. Support rod; 6. Second sound field generating component; 7. Z-axis displacement stage; 8. First sound field generating component; 9. Rotary clamping module; 10. Printing container; 61. Second ultrasonic transducer; 62. Second transducer support plate; 63. Second transducer bracket; 81. First transducer support plate; 82. First ultrasonic transducer; 83. First transducer mounting cavity; 84. First sealing gasket; 85. Second sealing gasket; 91. Connecting plate; 92. Support column; 93. Motor protective plate; 94. Hollow rotary motor; 95. Motor-clamping connector; 96. Self-centering clamping mechanism; 101. Transparent tube; 102. Third sealing gasket; 103. Tube sealing plug; 104. Refractive index matching liquid tank. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0023] Example 1 like Figure 1 As shown, this embodiment provides a sound field-assisted volumetric additive manufacturing device that integrates acoustic control, optical projection, and mechanical rotation functions, aiming to solve the problems of uncontrollable additive arrangement and difficulty in multi-physics coupling during volumetric printing.

[0024] The device mainly includes a printing container 10, a first sound field generating component 8, a second sound field generating component 6, a spacing adjustment mechanism, an acoustic impedance matching structure, and a rotary projection curing component. The printing container 10 is used to contain photocurable printing material containing additives, and its bottom boundary is made of acoustically transparent material to allow sound waves to efficiently penetrate the container. The first sound field generating component 8 and the second sound field generating component 6 are respectively disposed at the upper and lower ends of the printing container 10 along its axial direction. They work together to form a stable acoustic standing wave field within the printing container 10, using acoustic radiation force to drive the directional migration of the additives. The spacing adjustment mechanism is connected to the first sound field generating component 8 and / or the second sound field generating component 6 to adjust the effective acoustic distance between them to adapt to the standing wave formation conditions of different material systems. The acoustic impedance matching structure includes an acoustic communication portion disposed between the emitting end of the first sound field generating component 8 and the photocurable printing material. This acoustic communication portion eliminates the air gap between the first sound field generating component 8 and the photocurable printing material, thereby significantly reducing interface acoustic energy loss. The rotating projection curing component is used to drive the printing container 10 to rotate around its own axis and project multi-angle projection patterns onto the rotating printing container 10, so that the photocurable printing material undergoes volumetric photocuring under the state of acoustic field-induced arrangement.

[0025] In one specific implementation, the acoustic impedance matching structure is crucial for ensuring the effective coupling of acoustic field energy to the printing material. For example... Figure 3 and Figure 5 As shown, the acoustic connection section allows at least a portion of the emitting end face of the first sound field generating component 8 to be directly immersed in the photocurable printing material. This immersion design eliminates the unavoidable air layer in traditional non-contact sound conduction, significantly reducing sound energy reflection and coupling losses caused by air gaps, and improving the transmission efficiency of ultrasonic energy into the printing material. Simultaneously, the acoustic impedance of the acoustically transparent material at the bottom of the printing container 10 matches the acoustic impedance of the photocurable printing material to reduce interface reflection losses of sound waves at the bottom boundary of the printing container 10. For example, the acoustically transparent material can be at least one of silicone, polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), or flexible resin. These materials have acoustic impedances closer to those of the photocurable resin, serving as a good acoustic window, reducing echo interference at the bottom interface, and facilitating the formation of a high-purity standing wave field within the container.

[0026] Furthermore, such as Figure 3As shown, the specific structure of the first sound field generating component 8 includes a first transducer support plate 81, a first ultrasonic transducer 82, and a first transducer mounting cavity 83. The first transducer mounting cavity 83 is sealed to the upper end of the printing container 10 via a first sealing gasket 84 and a second sealing gasket 85. This mounting cavity serves not only as an injection port for the photocurable printing material but also as an acoustic coupling cavity, allowing the emitting end of the first ultrasonic transducer 82 to be stably immersed in the material. This integrated design ensures both sealing and continuity of the acoustic pathway. It should be understood that although the figure shows a layout where the first transducer is located at the top, in other embodiments, the position of the sound field generating component can be adjusted according to actual needs, provided that acoustic connectivity and immersion conditions are met.

[0027] Precise control of acoustic standing wave fields, such as Figure 1 and Figure 4 As shown, the spacing adjustment mechanism in this embodiment is specifically a Z-axis displacement stage 7, which drives the first sound field generating component 8 to move along the axial direction of the printing container 10, thereby changing the effective acoustic distance between it and the second sound field generating component 6. The effective acoustic distance here is not simply the mechanical spacing, but refers to the equivalent path length of sound waves propagating in the medium. Through precise adjustment of the Z-axis displacement stage 7, this effective acoustic distance can satisfy an integer or half-integer multiple relationship of the wavelength of sound waves in the photocurable printing material, thereby forming a stable acoustic standing wave field distributed along the axial direction within the printing container 10. This tunable mechanism allows the device to be compatible with printing materials with different sound velocities, adapting to various process requirements without replacing hardware. The second sound field generating component 6 includes a second ultrasonic transducer 61, a second transducer support plate 62, and a second transducer bracket 63. The second ultrasonic transducer 61 and the first ultrasonic transducer 82 are arranged opposite each other, jointly constructing an axial sound field.

[0028] In one specific implementation, such as Figure 2 As shown, the rotary projection curing assembly employs a rotary clamping module 9, which includes a connecting plate 91, a support column 92, a motor protective plate 93, a hollow rotary motor 94, and a self-centering clamping mechanism 96. The hollow rotary motor 94 is connected to the self-centering clamping mechanism 96 via a motor-clamping connector 95. The self-centering clamping mechanism 96 clamps the printing container 10 and maintains the axis of the printing container 10 strictly coaxial with the axis of rotation of the hollow rotary motor 94. This coaxiality control is crucial because any slight eccentric rotation will cause the position of the sound field nodes to drift periodically over time, thereby disrupting the orderly arrangement of the additives; at the same time, eccentricity will also cause geometric distortion of the projection light path, affecting the forming accuracy of volume printing. The self-centering clamping mechanism 96 effectively suppresses the above disturbances through mechanical self-adaptation or active centering, ensuring the spatial consistency of the sound field and light field during the dynamic process.

[0029] Furthermore, to ensure the stability of the acoustic-optical coupling environment, this embodiment also includes a refractive index matching container and a temperature regulation unit. For example... Figure 1 and Figure 5 As shown, the printing container 10 includes a transparent tube 101, a third sealing gasket 102, a tube sealing plug 103, and a refractive index matching liquid tank 104. The lower end of the transparent tube 101 is connected to the tube sealing plug 103, and the upper end is sealed to the first transducer mounting cavity 83. The transparent tube 101 is at least partially placed in the refractive index matching liquid tank 104, which contains a refractive index matching liquid, such as glycerin or a special matching oil, to reduce the refraction error of the projected light at the interface between the printing container 10, the photocurable printing material, and the external medium, and to eliminate aberrations caused by the curved container. The temperature control unit is specifically a cooling water tank 4, which is located on the outside of the printing container 10 and is used to maintain a constant temperature for the printing area. Since the ultrasonic action will generate a thermal effect, which may cause the photosensitive material to cure prematurely or the bioactive substances to deactivate, the cooling water tank 4 removes excess heat through circulating coolant to maintain the thermal balance of the printing system. Projector 1 is mounted on scissor lift platform 2 to provide the light source required for volumetric printing; camera module 3 is used to monitor the arrangement status inside the container in real time; support rod 5 is used to support Z-axis displacement stage 7. These auxiliary modules work together with the core sound field control module to form a complete sound field-assisted volumetric additive manufacturing system.

[0030] Example 2 like Figure 7 As shown, this embodiment provides a sound field-assisted volumetric additive manufacturing method. This method is applied to the sound field-assisted volumetric additive manufacturing apparatus described in Embodiment 1. Through time-series process control, the structural advantages of the apparatus are transformed into precise arrangement and curing of additives. The method mainly includes the following steps: Step S1: Inject photocurable printing material containing additives into the printing container 10, and use an acoustic impedance matching structure to make the emitting end of the first sound field generating component 8 acoustically connected to the photocurable printing material. Specifically, in this embodiment, the transparent tube 101 is first installed onto the self-centering clamping mechanism 96 and sealed to the first transducer mounting cavity 83. Then, photocurable printing material containing additives such as particles, fibers, or cells is injected into the transparent tube 101 through the first transducer mounting cavity 83. During the injection process, it is necessary to ensure that at least the emitting end face of the first ultrasonic transducer 82 is completely immersed in the printing material, thereby eliminating air gaps using the acoustic impedance matching structure described in Embodiment 1 and establishing an efficient acoustic transmission channel. At the same time, a refractive index matching liquid is added to the refractive index matching liquid tank 104 to match the refractive index of the transparent tube 101, the printing material, and the external medium, creating a low-distortion environment for subsequent optical projection.

[0031] Step S2: Activate the first sound field generating component 8 and the second sound field generating component 6, and adjust the effective acoustic distance using the Z-axis displacement stage 7 to form a standing wave field within the printing container 10, allowing the additives to form a preset arrangement. Specifically, this step is the core of the sound field construction. First, activate the first ultrasonic transducer 82 and the second ultrasonic transducer 61, making them operate at a preset initial frequency and power. Then, drive the first ultrasonic transducer 82 axially using the Z-axis displacement stage 7, finely adjusting the physical distance between it and the second ultrasonic transducer 61 until the effective acoustic distance corresponding to this distance meets the conditions for forming a standing wave field. Here, the effective acoustic distance refers to the equivalent path length of sound waves propagating in the printing material medium. Through this mechanical tuning method, a stable axial standing wave field can be established within the transparent tube 101, using acoustic radiation force to drive the additives to migrate towards the sound pressure nodes or sound pressure antinodes, forming a layered, strip-shaped, or periodic preset arrangement.

[0032] Furthermore, to adapt to the target arrangement of different additives, in addition to adjusting the axial spacing, the operating frequency, output power, or phase difference of the first ultrasonic transducer 82 and / or the second ultrasonic transducer 61 can be dynamically adjusted. For example, when a denser layered arrangement is required, the operating frequency can be increased to reduce the wavelength of the sound wave, thereby shortening the spacing between adjacent sound pressure nodes; when the additive concentration is high or the viscosity is high, making migration difficult, the output power can be appropriately increased to enhance the sound radiation force; when it is necessary to adjust the symmetry or position of the arrangement structure, the node position of the standing wave field can be moved by changing the phase difference between the two transducers. This multi-dimensional parameter adjustment mechanism enables the sound field control to flexibly adapt to the design requirements of various material systems and functional structures.

[0033] Step S3: Before starting the rotating clamping module 9, an image of the arrangement of the additives inside the printing container 10 is acquired through an image acquisition unit (e.g., camera module 3). Arrangement features are extracted based on the image, and it is determined whether the arrangement features meet a preset arrangement threshold. If not, the sound field parameters of the first sound field generating component 8 and the second sound field generating component 6 are adjusted until the arrangement features meet the preset arrangement threshold. Specifically, this is a key closed-loop verification step that differs from traditional open-loop control. In this embodiment, the camera module 3 is used to capture real-time images of the additive distribution inside the transparent tube 101. The control system processes the acquired images, extracts arrangement feature parameters such as interlayer spacing uniformity, orientation consistency, and aggregation density, and compares them with preset acceptable thresholds. If the arrangement features are found to be substandard, the system automatically triggers a feedback adjustment mechanism, fine-tuning the ultrasonic frequency, power, or the position of the Z-axis displacement stage 7, and re-acquires images for verification, forming a closed-loop iteration of "monitoring-judgment-adjustment" until the additive arrangement is stable and meets the preset requirements. This process effectively overcomes the uncertainty of the acoustic field caused by batch differences in materials, temperature fluctuations, or assembly errors, ensuring the accuracy and repeatability of the arrangement of additives before printing.

[0034] Step S4: With the additives arranged in a preset pattern, the rotating clamping module 9 is activated to synchronize the projection sequence of the multi-angle projection pattern with the rotation angle of the printing container 10, thereby accumulating a three-dimensional light dose distribution in the photocurable printing material and completing the volumetric photocurable printing. Specifically, after confirming that the additive arrangement is qualified, the sound field parameters are kept constant, and the projector 1 and the hollow rotary motor 94 are activated. To achieve high-precision volumetric curing, the projection sequence of the multi-angle projection pattern must be strictly synchronized with the rotation angle of the printing container 10. In this embodiment, based on the three-dimensional model to be printed, hundreds to thousands of two-dimensional projection patterns and their corresponding projection angle sequences are calculated using Laden transform, filtered back projection, or iterative optimization algorithms. During the printing execution phase, the control system drives the hollow rotary motor 94 to rotate the transparent tube 101 at a preset angular velocity, while simultaneously feeding back the rotation angle signal in real time through an encoder or Hall sensor. Based on this real-time angle signal, the projector 1 retrieves the corresponding projection pattern from the pre-calculated projection sequence and projects it accurately. This hardware-level angle synchronization mechanism ensures that each frame of projected light can accurately correspond to a specific slice position in the rotating container in space, so that the light dose is correctly accumulated in three-dimensional space, and finally solidifies a three-dimensional entity with the expected microstructure and macroscopic shape on the sound field-induced ordered additive skeleton.

[0035] It should be understood that although this embodiment describes the process as arrangement followed by curing, in other embodiments, a sound field can be continuously or intermittently applied during the curing process to dynamically maintain or adjust the arrangement of the additives while the curing reaction is underway, as long as the synergistic effect of sound field control and volumetric photocuring can be achieved. Furthermore, for heat-sensitive or shear-sensitive materials such as bio-inks, pulsed ultrasound or low-power modes can be used in steps S2 and S3, and active temperature control can be performed in step S4 using a cooling water tank 4 to maximize the maintenance of bioactivity while ensuring the arrangement effect.

[0036] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A sound field-assisted volumetric additive manufacturing apparatus, characterized in that, include: A printing container for holding photocurable printing material, wherein the bottom boundary of the printing container is made of sound-permeable material; The first sound field generating component and the second sound field generating component are respectively disposed at both ends of the printing container along the axial direction, for forming a standing wave field within the printing container; A spacing adjustment mechanism, connected to the first sound field generating component and / or the second sound field generating component, is used to adjust the effective acoustic distance between the first sound field generating component and the second sound field generating component; An acoustic impedance matching structure includes an acoustic communication portion disposed between the emitting end of the first sound field generating component and the photocurable printing material, the acoustic communication portion being used to eliminate the air gap between the first sound field generating component and the photocurable printing material; A rotating projection curing assembly is used to drive the printing container to rotate around its own axis and project multi-angle projection patterns onto the rotating printing container so that the photocurable printing material undergoes volumetric photocuring.

2. The acoustic field-assisted volumetric additive manufacturing apparatus according to claim 1, characterized in that, The acoustic connection portion is used to immerse the end face portion of the emitting end of the first sound field generating component in the photocurable printing material; The acoustic impedance of the sound-transmitting material is matched with the acoustic impedance of the photocurable printing material and / or the acoustic coupling medium to reduce the interface reflection loss of sound waves at the bottom boundary of the printing container.

3. The acoustic field-assisted volumetric additive manufacturing apparatus according to claim 2, characterized in that, The first sound field generating component includes a support plate, a first ultrasonic transducer, and a mounting cavity; The mounting cavity is sealed to the upper end of the printing container by a sealing gasket. The mounting cavity serves as an injection port for the photocurable printing material and an acoustic coupling cavity. At least a portion of the end face of the transmitting end of the first ultrasonic transducer is immersed in the photocurable printing material within the mounting cavity or the printing container; The sound-permeable material includes at least one of silicone, polydimethylsiloxane, thermoplastic polyurethane, or flexible resin.

4. The acoustic field-assisted volumetric additive manufacturing apparatus according to claim 1, characterized in that, The spacing adjustment mechanism is used to drive the first sound field generating component and / or the second sound field generating component to move along the axial direction of the printing container to change the effective acoustic distance; The effective acoustic distance satisfies the relationship of an integer multiple or a half-integer multiple of the acoustic wavelength in the photocurable printing material, so as to form the acoustic standing wave field distributed along the axis within the printing container.

5. The acoustic field-assisted volumetric additive manufacturing apparatus according to claim 1, characterized in that, The rotating projection curing assembly includes a hollow rotating motor and a self-centering clamping mechanism; The hollow rotary motor is connected to the self-centering clamping mechanism via a connector. The self-centering clamping mechanism is used to clamp the printing container and keep the axis of the printing container coaxial with the axis of rotation of the hollow rotary motor.

6. The acoustic field-assisted volumetric additive manufacturing apparatus according to claim 1, characterized in that, It also includes a refractive index matching container and a temperature control unit; The printing container is at least partially placed inside the refractive index matching container, which is used to contain a refractive index matching liquid to reduce the refraction error of the projected light at the interface between the printing container, the photocurable printing material and the external medium. The temperature regulation unit is located on the outside of the printing container and is used to regulate the temperature of the printing area.

7. A sound field-assisted volumetric additive manufacturing method, based on the sound field-assisted volumetric additive manufacturing apparatus according to any one of claims 1-6, characterized in that, include: Step S1: Inject a photocurable printing material containing additives into the printing container, and make the emitting end of the first sound field generating component acoustically connected to the photocurable printing material through the acoustic impedance matching structure; Step S2: Activate the first sound field generating component and the second sound field generating component, and adjust the effective acoustic distance through the spacing adjustment mechanism to form the acoustic standing wave field in the printing container, so that the additives form a preset arrangement; Step S3: When the additives form the preset arrangement, start the rotating projection curing component to synchronize the projection sequence of the multi-angle projection pattern with the rotation angle of the printing container, so as to accumulate a three-dimensional light dose distribution in the photocurable printing material and complete the volumetric photocurable printing.

8. The sound field-assisted volumetric additive manufacturing method according to claim 7, characterized in that, The step of adjusting the effective acoustic distance through the spacing adjustment mechanism to form the acoustic standing wave field within the printing container includes: Adjust the axial distance between the first sound field generating component and the second sound field generating component so that the effective acoustic distance meets the formation conditions of the acoustic standing wave field; Based on the target arrangement of the additives, the operating frequency, output power, or phase difference of the first sound field generating component and / or the second sound field generating component are dynamically adjusted.

9. The sound field-assisted volumetric additive manufacturing method according to claim 7, characterized in that, Before activating the rotary projection curing assembly, the following is also included: The image acquisition unit acquires an image of the arrangement of the additives inside the printing container. Based on the arrangement state image, the arrangement features are extracted, and it is determined whether the arrangement features meet the preset arrangement threshold. If the conditions are not met, the sound field parameters of the first sound field generating component and the second sound field generating component are adjusted in response to feedback until the arrangement feature meets the preset arrangement threshold.

10. The sound field-assisted volumetric additive manufacturing method according to claim 7, characterized in that, The rotating projection curing assembly includes a projection light source module and a rotating drive mechanism; The step of synchronizing the projection sequence of the multi-angle projection pattern with the rotation angle of the printing container includes: Based on the 3D model to be printed, a projection sequence of the multi-angle projection pattern is generated through Laden transform, filtered back projection, or iterative optimization algorithm. The projection light source module is controlled to output the multi-angle projection pattern according to the projection sequence, and the rotation drive mechanism is controlled to drive the printing container to rotate at a preset angular velocity, so that the projection angle of the multi-angle projection pattern corresponds to the real-time rotation angle of the printing container.

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