An ultrasonic 3D printing device and method

Abstract

The application relates to an ultrasonic 3D printing device and method, which comprises a signal generator, a power amplifier, two self-focusing ultrasonic transducers, a building chamber, a hydrophone and an oscilloscope. The signal generator is connected with the power amplifier, the power amplifier is connected with the two self-focusing ultrasonic transducers, a collimator is installed on the self-focusing ultrasonic transducer to make the ultrasonic beam more focused and directional, the two self-focusing ultrasonic transducers are symmetrically arranged left and right and are rotatably installed on a printing head movement driving mechanism in the building chamber through two mechanical arm mechanisms, the two self-focusing ultrasonic transducers are controlled to form an ultrasonic printing head through the mechanical arm mechanisms, the formed ultrasonic printing head is driven to move through the printing head movement driving mechanism to perform ultrasonic 3D printing, and the oscilloscope is connected with the building chamber through the hydrophone. The device and method can print a 3D printing piece without layering and with good strength, have high printing speed and high printing resolution, are strong in controllability, are easy to operate, and are low in printing cost.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and more specifically to an ultrasonic 3D printing device and method. Background Technology

[0002] Current 3D printing technologies primarily utilize light and heat as energy sources, but these methods cannot fully leverage the chemical potential in terms of parameter control. 3D printing of optically cured thermosetting materials can be achieved through methods such as SLA and LCD. However, efficient on-demand curing of thermosetting polymers has not yet been introduced due to the difficulty in applying very short heating and cooling rates to small localized areas. Acoustochemistry could be a solution for printing such materials because of its highly localized temperature and rapid heating and cooling rates. While acoustic-assisted manufacturing has been studied to some extent, these studies have been conducted in ultrasonic baths or horns, lacking the highly concentrated reaction zones and high polymerization rates necessary for 3D printing.

[0003] Furthermore, existing 3D printing technologies utilize light to achieve selective photopolymerization within the volume of optically transparent inks. However, the light attenuation of the ink itself, and the presence of already cured parts, limit the material selection and build size of light-based 3D printing. While infrared light can be used to increase light penetration to several millimeters, penetrating light into optically scattering media (such as biological tissue) remains a technological challenge. Therefore, existing 3D printing methods have inherent limitations in deep penetration manufacturing and minimally invasive manufacturing applications; current methods using light and heat as excitation sources primarily rely on the curing effect of lasers on the surface printing material during the printing process, thus requiring that there be no opaque medium between the laser source and the printing material. Summary of the Invention

[0004] The purpose of this invention is to provide an ultrasonic 3D printing device and method, which can print 3D printed parts without layering and with good strength, with fast printing speed, high printing resolution, strong controllability, easy operation, and low printing cost.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: an ultrasonic 3D printing device, comprising a signal generator, a power amplifier, two self-focusing ultrasonic transducers, a build chamber, a hydrophone, and an oscilloscope. The signal generator is connected to the power amplifier, which is also connected to the two self-focusing ultrasonic transducers. Each self-focusing ultrasonic transducer is equipped with a collimator to make the ultrasonic beam more focused and directional. The two self-focusing ultrasonic transducers are symmetrically arranged and rotatably mounted on a printhead motion drive mechanism in the build chamber via two robotic arms. The movement of the two robotic arms controls the two self-focusing ultrasonic transducers to form an ultrasonic printhead at a common focal point. The printhead motion drive mechanism drives the two self-focusing ultrasonic transducers and the formed ultrasonic printhead to move for ultrasonic 3D printing. The oscilloscope is connected to the build chamber via the hydrophone to assist in realizing the common focal point of the two self-focusing ultrasonic transducers by listening to the sound wave signal.

[0006] Furthermore, the robotic arm mechanism includes a mechanical support arm, a first swing mechanism, and a second swing mechanism. The rear end of the mechanical support arm is mounted on the print head motion drive mechanism via the first swing mechanism, and the self-focusing ultrasonic transducer is mounted on the front end of the mechanical support arm via the second swing mechanism. By controlling the swing of the front and rear ends of the mechanical support arm, the position and orientation of the self-focusing ultrasonic transducer can be adjusted, thereby achieving a common focal point for the two self-focusing ultrasonic transducers and adjusting the acoustic axis angle between the two self-focusing ultrasonic transducers to adjust the printing resolution.

[0007] Furthermore, the construction chamber includes an outer shell, a water chamber, a printing dish, a printing platform, a printing platform motion drive mechanism, a robotic arm mechanism, and a printhead motion drive mechanism. The printing platform is disposed inside the printing dish and mounted on the printing platform motion drive mechanism to move under the drive of the printing platform motion drive mechanism. The robotic arm mechanism is mounted on the printhead motion drive mechanism to move under the drive of the printhead motion drive mechanism.

[0008] Furthermore, it also includes a control unit, which is connected to a signal generator, a power amplifier, a robotic arm mechanism, an oscilloscope, and the printhead motion drive mechanism and the print platform motion drive mechanism in the construction chamber, respectively, to control the operation of each part.

[0009] The present invention also provides an ultrasonic 3D printing method based on the above-described device, comprising:

[0010] First, the imported model is analyzed and processed using CAM numerical control software to obtain printing parameters; then the printing material is imported into the construction chamber.

[0011] The printing power is generated based on the printing parameters. Then, the signal generator is turned on to emit a given sine wave signal. Next, the power amplifier is turned on to perform impedance matching and adjust to obtain the corresponding printing power, thereby controlling the self-focusing ultrasonic transducer to emit ultrasonic waves.

[0012] The movement of two robotic arms controls the common focal point of two self-focusing ultrasonic transducers to form an ultrasonic printhead. The position of the common focal point is the location of the formed ultrasonic printhead.

[0013] The printing path is formed according to the printing parameters, and then the print head motion drive mechanism is controlled to move the formed ultrasonic print head along the printing path on the printing material, applying the acoustic cavitation effect to the printing material to perform ultrasonic 3D printing. The printing material passed by the ultrasonic print head is accelerated to solidify and form a component.

[0014] After printing is complete, the cured component is removed from the uncured material.

[0015] Furthermore, during the ultrasonic 3D printing process, liquid printing material is solidified through acoustic cavitation effect and deposited onto the printing platform of the build chamber or onto the previously deposited and solidified area.

[0016] Furthermore, the ultrasonic printing head is formed by controlling the confocal point of two self-focusing ultrasonic transducers through the movements of two robotic arm mechanisms. The method for achieving this is as follows:

[0017] First, make the theoretical focal points of the two self-focusing ultrasonic transducers coincide. Then, move the focal points of the self-focusing ultrasonic transducers within a small area and listen to the sound wave signals using a hydrophone and an oscilloscope. Find the position where the waveform signal is the largest on the oscilloscope, which is the common focal point position.

[0018] Compared with existing technologies, the present invention has the following advantages: The present invention provides an ultrasonic 3D printing device and method. Compared with traditional optical 3D printing methods, this device and method can print in some opaque materials with better penetration depth. Furthermore, the emitted sound waves have adjustable center frequencies, a large sound wave spectrum bandwidth, higher printing resolution, and more precise control of the printed structure. Simultaneously, the results of ultrasonic printing are close to those of traditional thermosetting methods in terms of mechanical properties. In addition, the present invention uses two self-focusing ultrasonic transducers confocal to form an ultrasonic printing head. Its center frequency is higher than that of a single transducer, its frequency response bandwidth is wider, and the acoustic diffraction limit of the focused sound beam is narrower, improving the resolution of ultrasonic 3D printing. Moreover, it can use continuous sound fields of different frequencies for printing, allowing for precise control of the longitudinal printing position and improving printing accuracy. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the device implementation principle according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the internal structure of the construction chamber in an embodiment of the present invention;

[0021] Figure 3 These are simulation results of different acoustic axis angles in embodiments of the present invention;

[0022] Figure 4 This is a graph showing the effect of different acoustic axis angles on sound pressure and focal area in an embodiment of the present invention.

[0023] In the diagram: 1-Signal generator; 2-Power amplifier; 3-Self-focusing ultrasonic transducer; 4-Construction chamber; 5-Hydrophone; 6-Oscilloscope; 7-Water chamber; 8-Construction chamber shell; 9-Printing dish; 10-Printing platform; 11-Printing platform motion drive mechanism; 12-Robotic arm mechanism; 13-Collimator; 14-Print head motion drive mechanism; α-Acoustic axis angle. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0026] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] like Figure 1-2As shown, this embodiment provides an ultrasonic 3D printing device, including a signal generator 1, a power amplifier 2, two self-focusing ultrasonic transducers 3, a build chamber 4, a hydrophone 5, and an oscilloscope 6. The signal generator 1 is connected to the power amplifier 2, and the power amplifier 2 is also connected to the two self-focusing ultrasonic transducers 3. Each self-focusing ultrasonic transducer 3 is equipped with a collimator 13 to make the ultrasonic beam more focused and directional. The two self-focusing ultrasonic transducers 3 are arranged symmetrically from left to right and are rotatably mounted on a print head motion drive mechanism 14 in the build chamber 4 through two robotic arm mechanisms 12. The movement of the two robotic arm mechanisms 12 controls the two self-focusing ultrasonic transducers 3 to form an ultrasonic print head at a common focus. The print head motion drive mechanism 14 drives the two self-focusing ultrasonic transducers 3 and the formed ultrasonic print head to move for ultrasonic 3D printing. The oscilloscope 6 is connected to the build chamber 4 through the hydrophone 5 to assist in realizing the common focus of the two self-focusing ultrasonic transducers by listening to the sound wave signal.

[0028] In this embodiment, the robotic arm mechanism 12 includes a mechanical support arm, a first swing mechanism, and a second swing mechanism. The rear end of the mechanical support arm is mounted on the print head motion drive mechanism via the first swing mechanism, and the self-focusing ultrasonic transducer is mounted on the front end of the mechanical support arm via the second swing mechanism. The position and orientation of the self-focusing ultrasonic transducer are adjusted by controlling the swing of the front and rear ends of the mechanical support arm, thereby achieving a common focal point for the two self-focusing ultrasonic transducers and adjusting the acoustic axis angle between the two self-focusing ultrasonic transducers to adjust the printing resolution.

[0029] It should be noted that this device combines a self-focusing ultrasound transducer and an ultrasound collimator, that is, a collimator is added before the self-focusing transducer. The addition of the collimator can make the ultrasound beam more focused and directional, reduce beam divergence and scattering, and greatly improve the utilization rate of acoustic energy; by blocking unwanted ultrasound signals, sidelobe effects and noise interference are reduced; the collimator can accurately focus the ultrasound energy to the lesion site, ensuring that the focal position receives sufficient energy, improving the effectiveness of printing, while minimizing disturbance to the surrounding medium and reducing the risk of curing non-target areas.

[0030] In this embodiment, the construction chamber 4 includes an outer shell 8, a water chamber 7, a printing dish 9, a printing platform 10, a printing platform motion drive mechanism 11, a robotic arm mechanism 12, and a print head motion drive mechanism 14. The printing platform 10 is disposed inside the printing dish 9 and mounted on the printing platform motion drive mechanism 11 to move under the drive of the printing platform motion drive mechanism. The robotic arm mechanism 12 is mounted on the print head motion drive mechanism 14 to move under the drive of the print head motion drive mechanism.

[0031] In this embodiment, the ultrasonic 3D printing device also includes a control unit, which is connected to a signal generator, a power amplifier, a robotic arm mechanism, an oscilloscope, and the print head motion drive mechanism and the print platform motion drive mechanism in the construction chamber, respectively, to control the operation of each part.

[0032] This embodiment also provides an ultrasonic 3D printing method based on the above-mentioned device, including:

[0033] S1. First, use CAM numerical control software to analyze and process the imported model to obtain printing parameters; then import the printing material into the construction chamber.

[0034] S2. Based on the printing parameters, the printing power is generated. Then, the signal generator is turned on to emit a given sine wave signal. Next, the power amplifier is turned on to perform impedance matching and adjust to obtain the corresponding printing power, thereby controlling the self-focusing ultrasonic transducer to emit ultrasonic waves.

[0035] S3. The movement of the two robotic arms controls the two self-focusing ultrasonic transducers to form an ultrasonic printhead by confocaling. The position of the confocal point is the location of the formed ultrasonic printhead.

[0036] First, determine the required printing resolution. Then, adjust the acoustic axis angle between the two transducers using the actions of two robotic arms (12). Since the acoustic focus is formed by the interference of two ultrasonic beams, precise alignment of the two beams is crucial. First, align the theoretical focal points of the two self-focusing ultrasonic transducers. Then, move the focal points of the self-focusing ultrasonic transducers within a small area. Listen to the acoustic signals using a hydrophone and oscilloscope. Find the position with the maximum waveform signal on the oscilloscope; this is the confocal position. Ensure the actual position is accurate.

[0037] When determining print resolution, both print accuracy and print efficiency must be considered. Higher resolution results in higher print accuracy but lower print efficiency; conversely, lower resolution results in lower print accuracy but higher print efficiency.

[0038] S4. A printing path is formed according to the printing parameters. Then, the print head motion drive mechanism is controlled to move the ultrasonic print head along the printing path on the printing material, applying an acoustic cavitation effect to the printing material for ultrasonic 3D printing. The printing material passing through the ultrasonic print head solidifies faster and forms a component. The liquid printing material is solidified through the acoustic cavitation effect and deposited onto the printing platform in the build chamber or on top of the previously deposited and solidified area.

[0039] S5. After printing, remove the cured component from the uncured material.

[0040] This invention addresses the limitations of existing 3D printing technologies, such as their inability to print materials with poor photosensitivity and their inability to penetrate media. It provides an ultrasonic 3D printing device and method, and through the confocal design of dual self-focusing ultrasonic transducers, it improves printing resolution and reduces the cost of the printing equipment. Sound waves, as mechanical waves, have a wide wavelength range and relatively low frequency (compared to light waves). Sound wave energy can penetrate most media to reach the working plane. Based on these characteristics, acoustic 3D printing is achieved by generating a localized sonochemical reaction in the printing material through a high-energy focused sound field. This allows for printing within the penetrating medium and can also print structures with different porosities.

[0041] In this invention, the electrical signal generated by signal generator 1 is amplified by power amplifier 2, driving the ultrasonic field generated by self-focusing ultrasonic transducer 3 to reach the printing material after passing through the shell of the build chamber. At the confocal point in the printing material, the chemically active acoustic cavitation region solidifies the liquid printing material (resin or mixture, etc.) and deposits it onto the printing platform or onto the top of the previously deposited and solidified area. We call this region the ultra-active micro-reaction zone, where the generated bubbles and polymerized resin appear in the low-pressure area and then instantly migrate to the high-pressure area until they reach the platform or the previously solidified pixel, where they are deposited. The transducer is moved by a printhead motion drive mechanism to locate the focused area along the calculated path in the build chamber, thereby creating the designed section point by point. The stability of the acoustic signal output during the process is observed using a hydrophone 5 and an oscilloscope 6.

[0042] However, using a single high-energy focusing transducer results in a narrow center frequency response bandwidth and a wide acoustic diffraction limit for the focused sound beam, leading to insufficient lateral resolution in printing. Furthermore, the use of single-frequency continuous sound field printing makes it difficult to precisely control the longitudinal printing position, reducing printing accuracy. Therefore, this invention innovatively designs two high-intensity ultrasonic transducers where the ultrasonic parameters / excitation parameters (frequency, pulse width, pulse repetition frequency, etc.) in the acoustic printing area can be synchronized and controlled via a signal generator. By changing the focused shape and size through confocal modulation and controlling the acoustic energy intensity, objects with different focal sizes (i.e., resolutions) can be printed, increasing lateral resolution and allowing for more precise control during the printing process. Different acoustic axis angles between the transducers result in different focal areas and focal acoustic energy, as shown in the simulation results. Figure 3 , 4 As shown.

[0043] By intersecting the beams of two self-focusing ultrasonic transducers, the axial focal size and focal volume can be significantly reduced. The overlapping region of the two acoustic beams forms a new focal spot, resulting in a much smaller focal area compared to the single-transducer mode. Another important advantage of this device is that each transducer in the dual-transducer configuration requires a lower ultrasonic beam intensity compared to a single transducer, which can significantly reduce the cost of the equipment. Furthermore, since the parameters of each transducer in the dual-transducer configuration are significantly reduced compared to a single transducer, this device can also significantly reduce medium disturbances in the original acoustic wave path.

[0044] Simulation analysis:

[0045] In finite element simulations, consider a few examples. When the acoustic axis angle is 45°, as the phase shifts from in-phase to out-of-phase, the intensity of the single main focal lobe decreases, splitting into two side lobes. We confirmed a similar phenomenon at an acoustic axis angle of 60°. Conversely, at an acoustic axis angle of 90°, even under in-phase conditions, two side lobes exist on either side of the main lobe, but the intensity and shape of this pattern do not change significantly as the focus misalignment worsens. Therefore, due to the presence of side lobes, the lateral resolution is worse at 90° compared to the 45° and 60° angles, but 90° offers the highest axial resolution and robustness to errors caused by misalignment. Thus, different angles have different advantages and disadvantages, application scenarios, and resolutions.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An ultrasonic 3D printing method, characterized in that, An ultrasonic 3D printing device is provided, including a signal generator, a power amplifier, two self-focusing ultrasonic transducers, a build chamber, a hydrophone, and an oscilloscope. The signal generator is connected to the power amplifier, which is also connected to the two self-focusing ultrasonic transducers. Each self-focusing ultrasonic transducer is equipped with a collimator to make the ultrasonic beam more focused and directional. The two self-focusing ultrasonic transducers are symmetrically arranged and rotatably mounted on a printhead motion drive mechanism in the build chamber through two robotic arms. The movement of the two robotic arms controls the two self-focusing ultrasonic transducers to form a common focal point to form an ultrasonic printhead. The printhead motion drive mechanism drives the two self-focusing ultrasonic transducers and the formed ultrasonic printhead to move for ultrasonic 3D printing. The oscilloscope is connected to the build chamber through the hydrophone to monitor the sound wave signal to assist in realizing the common focal point of the two self-focusing ultrasonic transducers. The robotic arm mechanism includes a mechanical support arm, a first swing mechanism, and a second swing mechanism. The rear end of the mechanical support arm is mounted on the print head motion drive mechanism via the first swing mechanism, and the self-focusing ultrasonic transducer is mounted on the front end of the mechanical support arm via the second swing mechanism. The position and orientation of the self-focusing ultrasonic transducer are adjusted by controlling the swing of the front and rear ends of the mechanical support arm, thereby achieving a common focal point for the two self-focusing ultrasonic transducers and adjusting the acoustic axis angle between the two self-focusing ultrasonic transducers to adjust the printing resolution. The construction chamber includes an outer shell, a water chamber, a printing dish, a printing platform, a printing platform motion drive mechanism, a robotic arm mechanism, and a print head motion drive mechanism. The printing platform is disposed inside the printing dish and mounted on the printing platform motion drive mechanism to move under the drive of the printing platform motion drive mechanism. The robotic arm mechanism is mounted on the print head motion drive mechanism to move under the drive of the print head motion drive mechanism. The ultrasonic 3D printing device also includes a control unit, which is connected to a signal generator, a power amplifier, a robotic arm mechanism, an oscilloscope, and the print head motion drive mechanism and the print platform motion drive mechanism in the construction chamber, respectively, to control the operation of each part; An ultrasonic 3D printing method based on the ultrasonic 3D printing device includes: First, the imported model is analyzed and processed using CAM numerical control software to obtain printing parameters; then the printing material is imported into the construction chamber. The printing power is generated based on the printing parameters. Then, the signal generator is turned on to emit a given sine wave signal. Next, the power amplifier is turned on to perform impedance matching and adjust to obtain the corresponding printing power, thereby controlling the self-focusing ultrasonic transducer to emit ultrasonic waves. The movement of two robotic arms controls the common focal point of two self-focusing ultrasonic transducers to form an ultrasonic printhead. The position of the common focal point is the location of the formed ultrasonic printhead. The printing path is formed according to the printing parameters, and then the print head motion drive mechanism is controlled to move the formed ultrasonic print head along the printing path on the printing material, applying the acoustic cavitation effect to the printing material to perform ultrasonic 3D printing. The printing material passed by the ultrasonic print head is accelerated to solidify and form a component. After printing is complete, remove the cured component from the uncured material; During ultrasonic 3D printing, liquid printing material is solidified through acoustic cavitation effect and deposited onto the printing platform of the build chamber or on top of the previously deposited and solidified area. The ultrasonic printing head is formed by controlling the confocal point of two self-focusing ultrasonic transducers through the movements of two robotic arms. The method for achieving this is as follows: First, make the theoretical focal points of the two self-focusing ultrasonic transducers coincide. Then, move the focal points of the self-focusing ultrasonic transducers within a small area and listen to the sound wave signals using a hydrophone and an oscilloscope. Find the position where the waveform signal is the largest on the oscilloscope, which is the common focal point position.

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