Scraper type photocuring biological 3D printing device and method based on temperature-sensitive material

Abstract

The invention provides a scraper type photocuring biological 3D printing device and method based on a temperature-sensitive material. The device comprises a workbench, a driving mechanism, a printing cylinder, an objective lens, a heating pad, a mounting frame and a lifting table. The driving mechanism comprises a first driving assembly and a second driving assembly, a mounting plate for mounting the printing cylinder is arranged at the end, away from the workbench, of the mounting frame, a scraper is arranged at the end, close to the workbench, of the mounting frame, the printing cylinder is provided with a storage cavity for storing printing liquid, and the end, close to the workbench, of the printing cylinder is connected with an injection needle. The lifting table is arranged on the lower surface of the workbench, a lifting block of the lifting table is partially embedded into the through hole to form a printing groove, the objective lens is arranged above the printing groove, and heating pads are arranged on the scraping plate and the printing cylinder. Thus, under the driving of the driving mechanism, the mounting plate can accurately move on the workbench according to the printing requirement, then layer-by-layer printing is conducted in the printing groove, and finally a complete model can be formed.

Description

Technical Field

[0001] The invention belongs to the technical field of 3D printing, and in particular relates to a scraper-type photocuring biological 3D printing device and method based on temperature-sensitive materials. Background Art

[0002] Bio-3D printing is a technology that uses living cells, bioactive factors and biomaterials as basic molding units to design and manufacture artificial organs, implants or three-dimensional cell structures with biological activity. It integrates manufacturing science and biomedicine and is an emerging technology with cross-cutting and cutting-edge characteristics. Bio-3D printing technology can meet personalized, small-batch and large-scale medical needs. It has been widely used in the field of in vitro medical device manufacturing and is now expanding into personalized permanent implants, clinical repair treatments and drug development trials. In the future, it will be committed to the direct printing of biological tissues and organs.

[0003] In the related art, the two mainstream technologies of biological 3D printing are photocuring 3D bioprinting and extrusion 3D bioprinting. Among them, extrusion printing technology is the most widely used bioprinting method, which can print biological materials with high viscosity. This method uses air pressure or mechanically driven nozzles to controllably extrude biological ink and deposit it onto a forming platform to form a two-dimensional structure. With the movement of the nozzle or the forming platform in the z direction, the two-dimensional structure is stacked layer by layer to form a three-dimensional structure; photocuring printing uses light to selectively cross-link biological ink, and solidifies layer by layer to form a three-dimensional structure. The curing light is selectively projected onto the surface of the biological ink through a digital micromirror device, and the material in the irradiated area begins to solidify. Through the up and down movement of the forming platform, the three-dimensional structure is solidified layer by layer;

[0004] Extrusion 3D printing can use a tiny needle to print a very fine three-dimensional structure, but as the needle shrinks, the shear stress inside the bio-ink when it is extruded will seriously affect the survival rate of the cells in the bio-ink. In addition, the printing time of extrusion 3D bio-printing, a one-dimensional printing method, is relatively long. If you want to achieve a finer structure and use a thinner needle, it will take longer to print the sample; photocuring 3D bio-printing is faster than extrusion, but due to the diffusion of components in the bio-ink during the printing process, the printing accuracy is relatively limited, and because the bio-hydrogel is generally soft, many printed bodies will deform during the movement of the forming platform, and some materials with a high degree of hollowing will fail to form during the printing process. Moreover, since the printed product needs to contact the forming plane, these two methods cannot print floating structures and curved structures. For this reason, it is urgent to develop high-precision biological 3D printing equipment that can print high-rise-to-empty ratio, curved and floating structures. Summary of the invention

[0005] In view of this, the purpose of the present invention is to propose a scraper-type photocuring biological 3D printing device and method based on temperature-sensitive materials, which can print high-rise-to-space ratio, curved surfaces and floating structures with high precision, so as to at least partially solve the problems in the related art.

[0006] To achieve the above-mentioned purpose, the first aspect of the invention provides a scraper-type photocuring biological 3D printing device based on temperature-sensitive materials, comprising: a workbench, a driving mechanism, a printing cylinder, an objective lens, a heating pad, a mounting frame and a lifting platform;

[0007] The driving mechanism includes a first driving component and a second driving component, the first driving component is used to drive the second driving component to reciprocate along the height direction of the lifting platform, the second driving component is used to drive the mounting frame to reciprocate along the length direction of the workbench, the mounting frame is provided with a mounting plate for mounting the printing cylinder at one end away from the workbench, and the mounting frame is provided with a scraper at one end close to the workbench, the printing cylinder has a storage cavity for storing printing liquid, and the end of the printing cylinder close to the workbench is connected to an injection needle connected to the storage cavity, the workbench is provided with a through hole, the lifting platform is arranged on the lower surface of the workbench and the lifting block of the lifting platform is partially embedded in the through hole to form a printing groove, the objective lens is arranged above the printing groove, the scraper and the printing cylinder are provided with the heating pad, the temperature in the printing groove is lower than the temperature of the printing cylinder, so that the printing liquid scraped into the printing groove is gelled to form a printing layer.

[0008] Furthermore, it also includes a collection box, which is arranged under the workbench and has a storage cavity for storing printing liquid. The collection box is connected to the printing cylinder through a hose so that the storage cavity is connected to the inside of the storage cavity.

[0009] Furthermore, the heating pad is provided on the collection box.

[0010] Furthermore, a collecting slot and a discharge position are provided on the workbench, the collecting slot and the discharge position are arranged opposite to each other, and the printing slot is located between the collecting slot and the discharge position.

[0011] Furthermore, a discharge port is provided at the bottom of the collecting tank, and the discharge port is located directly above the opening of the collecting box.

[0012] Furthermore, the cross-sectional area of ​​the collecting tank gradually decreases from the lower surface of the workbench to the upper surface of the workbench.

[0013] Furthermore, a plurality of heating pads are installed on the workbench to heat the location of the collecting tank and the location of the discharge position.

[0014] A second aspect of the present disclosure also provides a center console assembly, including a center console screen and the fixing bracket as described above.

[0015] The second aspect of the invention also provides a scraper-type photocuring biological 3D printing method based on a temperature-sensitive material, which is applicable to a scraper-type photocuring biological 3D printing device based on a temperature-sensitive material as described above, and the method comprises:

[0016] Step 1: Start the second driving assembly to move the mounting frame from the initial position to the discharge position and discharge the printing liquid out of the storage chamber through the injection needle;

[0017] Step 2: The scraper moves toward the collecting tank through the second driving assembly, wherein part of the printing liquid at the discharge position is scraped into the printing tank, and the remaining part of the printing liquid is scraped into the collecting tank after passing through the printing tank, and then discharged into the collecting box through the discharge port;

[0018] Step 3: Projecting the pre-processed sliced ​​image of the model to be printed onto the printing liquid in the printing tank through the objective lens, thereby causing a free radical polymerization reaction to produce chemical cross-linking;

[0019] Step 4: Start the first driving assembly to move the mounting frame away from the workbench, and then control the mounting frame to move toward the discharge position and return to the initial position through the second driving assembly, and start the lifting platform to control the lifting block to move so that the depth of the printing slot increases;

[0020] Step 5: Repeat the above steps until printing is completed.

[0021] Through the above technical solution, the mounting frame can be accurately moved on the workbench according to the printing requirements under the coordinated action of the first drive component and the second drive component, that is, under the drive of the second drive component, the mounting frame moves from the initial position toward the printing groove. As the mounting frame moves, the printing liquid ejected from the injection needle will be evenly scraped into the printing groove by the scraper to ensure that the printing liquid can form a uniform printing layer after gelation in the printing groove. After the printing layer is formed, the printing layer is illuminated and projected by an objective lens arranged above the printing groove. The projection content is a pre-processed model slice image. The purpose is to illuminate the gelled printing layer according to each layer structure of the model to be printed. The area where the printing layer is illuminated will trigger a free radical polymerization reaction, resulting in irreversible chemical crosslinking of the gelled printing liquid that forms physical crosslinks. After the crosslinking of this layer is completed, under the coordinated action of the first drive component and the second drive component, the mounting frame returns to the initial position, and the lifting block of the lifting platform moves downward by the thickness of a printing layer to leave space for the scraping and curing of the next layer of printing liquid. Based on this, by gradually curing each printing layer, a complete model can be formed.

[0022] In summary, the addition of temperature-sensitive materials enables precise control of the flow characteristics of the printing liquid. That is, the temperature of the printing liquid can be precisely controlled during the printing process through the heating pad, so that the fluidity of the printing liquid and the stability after gelation can be precisely adjusted according to actual needs. After the printing liquid is gelled, it can support the solidified area in each printing layer, avoiding collapse or deformation caused by gravity. While ensuring high-precision printing, it can also overcome the limitations of traditional technology in printing complex geometric shapes such as floating structures and curved structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0024] Figure 1 is a schematic diagram of the overall structure of the device provided in an exemplary embodiment of the present disclosure;

[0025] Figure 2 is a schematic structural diagram of a workbench provided in an exemplary embodiment of the present disclosure;

[0026] Figure 3 Schematic diagram of the structure of a lifting platform provided in an exemplary embodiment of the present disclosure.

[0027] Description of reference numerals:

[0028] 1. Workbench; 101. Collecting tank; 1011. Discharge port; 102. Discharge position; 103. Through hole; 2. Print cylinder; 3. Objective lens; 4. Heating pad; 5. Mounting frame; 501. Mounting plate; 502. Scraper; 6. Lifting platform; 601. Lifting block; 7. First drive assembly; 8. Second drive assembly; 9. Collecting box; 10. Hose. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0031] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0032] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0033] In a first aspect of the present disclosure, a scraper-type photocuring biological 3D printing device based on a temperature-sensitive material is provided, referring to Figures 1 to 3As shown, the scraper-type photocuring biological 3D printing device based on temperature-sensitive materials includes: a workbench 1, a driving mechanism, a printing cylinder 2, an objective lens 3, a heating pad 4, a mounting frame 5 and a lifting platform 6, wherein the driving mechanism includes a first driving component 7 and a second driving component 8, the first driving component 7 is used to drive the second driving component 8 to reciprocate along the height direction of the lifting platform 6, and the second driving component 8 is used to drive the mounting frame 5 to reciprocate along the length direction of the workbench 1, and the mounting frame 5 is provided with a mounting plate 501 for mounting the printing cylinder 2 at one end away from the workbench 1, and the mounting frame 5 is close to the workbench 1. A scraper 502 is provided at one end of the printing cylinder 2, and the printing cylinder 2 has a storage cavity for storing printing liquid, and the printing liquid is a photocurable biological ink containing a temperature-sensitive material. An injection needle connected to the storage cavity is connected to the end of the printing cylinder 2 close to the workbench 1. The workbench 1 has a through hole 103. The lifting platform 6 is arranged on the lower surface of the workbench 1 and the lifting block 601 of the lifting platform 6 is partially embedded in the through hole 103 to form a printing groove. The objective lens 3 is arranged above the printing groove. A heating pad 4 is provided on the scraper 502 and the printing cylinder 2. The heating pad 4 can heat the printing liquid to make it have good fluidity.

[0034] Through the above technical solution, the mounting frame 5 can move accurately on the workbench 1 according to the printing requirements under the coordinated action of the first driving component 7 and the second driving component 8, that is, under the drive of the second driving component 8, the mounting frame 5 moves from the initial position toward the printing slot. As the mounting frame 5 moves, the printing liquid ejected from the injection needle will be evenly scraped into the printing slot by the scraper 502, ensuring that the printing liquid can form a uniform printing layer after gelation in the printing slot. After the printing layer is formed, the printing layer is illuminated and projected by the objective lens 3 arranged above the printing slot. The projection content is a pre-processed model slice image. The purpose is to illuminate the gelled printing layer according to each layer structure of the model to be printed. The area where the printing layer is illuminated will trigger a free radical polymerization reaction, resulting in the formation of The physically cross-linked gelled printing liquid undergoes irreversible chemical cross-linking. After the cross-linking of this layer is completed, under the coordinated action of the first drive component 7 and the second drive component 8, the mounting frame 5 returns to the initial position, and the lifting block 601 of the lifting platform 6 moves downward by the thickness of a printing layer to leave space for the scraping and curing of the next layer of printing liquid. Based on this, by gradually curing each printing layer, a complete model can be formed in the end. In addition, the 3D printing device uses temperature-sensitive materials as the printing substrate, which can better control the flow characteristics and curing accuracy of the printing liquid, so that problems such as uneven material flow or structural collapse are avoided during high-precision printing, thereby achieving printing of finer structures and more complex geometric shapes, and overcoming the limitation of being unable to print floating structures and curved structures.

[0035] Exemplarily, when scraping the printing liquid into the printing groove, the scraper 502 can also scrape excess printing liquid out of the printing groove, so that the printing layer formed after the printing liquid is gelled has good flatness, thereby optimizing the printing accuracy.

[0036] Exemplarily, the printing liquid is a photocurable biological ink containing a temperature-sensitive material, wherein the heating pad 4 provided on the scraper 502 and the printing cylinder 2 can ensure that the printing liquid has good fluidity, so that the printing liquid can flow evenly at a suitable temperature and be smoothly extruded through the injection needle, ensuring that the viscosity and fluidity of the material remain in an optimal state during the printing process.

[0037] Exemplarily, the printing slot is not provided with a heating pad 4, and the printing liquid scraped into the printing slot will gel as the temperature decreases, thereby forming a printing layer.

[0038] Explanation of the model slice images: Since the 3D printing process is carried out layer by layer, each layer is printed on the basis of the previous layer. Therefore, the 3D model to be printed is divided into several layers of slice images. Through layer-by-layer projection, each printed layer can be accurately solidified.

[0039] Exemplarily, the light in the slice image projected onto the print layer in the print tank will trigger a chemical reaction in the print liquid, that is, a free radical polymerization reaction; the light will cause the photosensitive material in the print liquid to produce free radicals, and the free radicals will further react chemically with the curing component to cause the irradiated area to be cross-linked and cured. Each layer of the slice image will be projected layer by layer onto the gelled print layer through the objective lens 3. After the illuminated area is cured, the next layer of print liquid will be coated on the cured area of ​​the previous layer, and then cured through the same process. Through this layer-by-layer projection and curing process, a complete model to be printed is finally constructed.

[0040] Description of free radical polymerization reaction: The photoinitiator in the printing liquid is cleaved under the irradiation of a light source of a specific wavelength to generate free radicals. Through the free radical chain growth polymerization reaction, the monomer molecules are polymerized into a network structure, which is manifested as the solidification of the liquid printing liquid (bio-ink) from a macroscopic perspective; ideally, only the ink reaction in the projection area solidifies, but since the free radicals diffuse and cause the non-projection area to solidify, the actual solidification area is larger than the projection area, and the fine structure with a scale smaller than the free radical diffusion distance cannot be printed due to over-curing; therefore, reducing the free radical diffusion distance is an effective means to improve the accuracy of photopolymerization 3D printing technology; the average diffusion distance L of free radicals follows Fick's diffusion law:

[0041]

[0042] Where D is the diffusion coefficient and t is the average radical lifetime. The diffusion coefficient D can be expressed as:

[0043]

[0044] Among them, k B is the Boltzmann constant, T is the temperature, μ is the viscosity coefficient of the solution, r p is the radius of the solute molecule. It can be concluded from the formula that increasing the viscosity coefficient μ of the bio-ink will reduce the diffusion coefficient D, thereby shortening the diffusion distance of the free radicals. By gelling the printing liquid (bio-ink) during the curing process, the viscosity of the printing liquid (bio-ink) can be increased, thereby significantly limiting the diffusion of free radicals and improving the printing resolution. Therefore, in order to make the printing liquid gel better in the printing tank, the device can be set in a low temperature environment for use, and the ambient temperature should be around 15°C.

[0045] In addition to free radical diffusion, the light scattering effect is also an important factor affecting the printing resolution. Light has a lower penetration depth and a wider scattering area in a printing fluid with a high scattering coefficient, which has a very adverse effect on the printing resolution. The scattering coefficient of the printing fluid will increase during the photocuring process, thus affecting the printing effect. This phenomenon is called turbidity of the printing fluid. Due to the increased viscosity, the gelled printing fluid has smaller unevenness during free radical polymerization. Compared with the liquid printing fluid, its scattering coefficient after curing is lower and has a higher resolution.

[0046] In some embodiments, reference Figure 1 As shown, it also includes a collecting box 9, which is arranged under the workbench 1. The collecting box 9 has a storage cavity for storing printing liquid. The collecting box 9 is connected to the printing cylinder 2 by a hose 10, so that the storage cavity is connected to the inside of the storage cavity. The printing liquid in the storage cavity can flow into the storage cavity of the printing cylinder 2 through the hose 10.

[0047] In some embodiments not shown in the figure, the printing cylinder 2 may also be provided with a syringe pump, which can accurately control the amount of printing liquid discharged by the injection needle, thereby avoiding excessive or insufficient printing liquid.

[0048] Exemplarily, in order to ensure that the printing liquid stored in the collection box 9 has good fluidity, a heating pad 4 is provided on the collection box 9, that is, the heating pad 4 ensures that the printing liquid does not become too viscous in a low temperature environment, helps maintain its good fluidity, and avoids clogging the hose 10.

[0049] Exemplarily, a release film made of FEP is attached to the wall of the printing slot, so that when the lifting block 601 descends, the printing layer does not adhere to the wall.

[0050] In some embodiments, reference Figure 1 and Figure 2As shown, a collecting tank 101 and a discharge position 102 are provided on the workbench 1, and the collecting tank 101 and the discharge position 102 are arranged opposite to each other, and the printing tank is located between the collecting tank 101 and the discharge position 102, wherein, before the scraper 502 scrapes the printing liquid into the printing tank, the printing liquid can be discharged onto the discharge position 102, and then the printing liquid located on the discharge position 102 is scraped into the printing tank by the scraper 502. In order to enable the scraper 502 to evenly scrape the printing liquid into the printing tank, the size of the scraper 502 should be larger than the size of the printing tank. At the same time, a layer of release film made of polytetrafluoroethylene propylene is wrapped on the scraper 502, and the release film made of polytetrafluoroethylene propylene can ensure that the scraper 502 does not adhere to the printing liquid when scraping the printing liquid.

[0051] In some embodiments, reference Figure 1 and Figure 2 As shown, the collecting slot 101 and the discharge position 102 are arranged opposite to each other and the printing slot is located between the collecting slot 101 and the discharge position 102. The collecting slot 101 is used to collect the excess printing liquid scraped from the printing slot. That is, in order to ensure the integrity of the print layer in the printing slot, the milliliter amount of printing liquid discharged to the discharge position 102 each time should be greater than the required milliliter amount. Therefore, by setting the collecting slot 101 to collect the excess printing liquid scraped from the printing slot, the waste of printing liquid can be effectively avoided.

[0052] In some embodiments, reference Figure 1 and Figure 2 As shown, a discharge port 1011 is provided at the bottom of the collecting tank 101, and the discharge port 1011 is located directly above the opening of the collecting box 9, that is, the printing liquid in the collecting tank 101 can flow back into the collecting box 9 through the discharge port 1011, so that the excess printing liquid can be recycled and reused, reducing the consumption of materials during the printing process and reducing the printing cost.

[0053] In some embodiments not shown in the figures, the cross-sectional area of ​​the collecting groove 101 gradually decreases from the lower surface of the workbench 1 to the upper surface of the workbench 1, that is, the collecting groove 101 is funnel-shaped. The funnel-shaped structure makes the bottom area of ​​the collecting groove 101 narrower, which can collect the printing liquid more concentratedly, thereby improving the efficiency of liquid collection and facilitating the return of the printing liquid to the collection box 9.

[0054] Illustratively, in order to ensure that the printing liquid has good fluidity on the workbench 1, a plurality of heating pads 4 are installed on the workbench 1 to heat the collection tank 101 and the discharge position 102. Similarly, in order to ensure the fluidity of the printing liquid in the hose 10, relevant heating facilities can be provided on the hose 10.

[0055] On the basis of the above technical solution, the second aspect of the present disclosure further provides a scraper-type photocuring biological 3D printing method based on a temperature-sensitive material, which is applicable to a scraper-type photocuring biological 3D printing device based on a temperature-sensitive material in the first aspect, and the method comprises:

[0056] Step 1: Start the second driving assembly 8, so that the mounting frame 5 moves from the initial position to the discharge position 102 and discharges the printing liquid out of the storage cavity through the injection needle;

[0057] Specifically, the printing liquid includes thermosensitive materials (which gel the printing liquid when the temperature is lowered, and are reversibly physically crosslinked), photoinitiators (which generate free radicals after being irradiated with light of a specific wavelength), curing monomers (which can be cured by free radicals to form a three-dimensional polymer network, and which irreversibly chemically crosslink the printing liquid), and light absorbers (substances that absorb light, and whose concentration is adjusted so that the light attenuation matches the printing layer thickness);

[0058] Before printing, the ambient temperature is controlled at about 15°C, at which time the printing liquid can gel within a suitable time, and multiple heating pads 4 are turned on at the same time, and the printing cylinder 2, the scraper 502, the collecting box 9, the collecting tank 101 and the discharge position 102 are heated by the heating pads 4, so that the printing liquid located therein remains in a flowable liquid state. At the same time, the depth of the printing tank needs to be adjusted to ensure that the depth of the printing tank is the thickness of a printing layer;

[0059] Before discharging the printing liquid through the injection needle, the air in the storage cavity can be discharged in advance, the printing liquid can be discharged to the discharge position 102 and the printing liquid can be scraped into the printing groove through the scraper 502, which can effectively improve the flatness of the printing liquid scraped into the printing groove.

[0060] Step 2: The scraper 502 is moved toward the collecting tank 101 by the second driving assembly 8, wherein part of the printing liquid located on the discharge position 102 is scraped into the printing tank, and the remaining part of the printing liquid is scraped into the collecting tank 101 after passing through the printing tank, and then discharged into the collecting box 9 through the discharge port 1011;

[0061] Specifically, the scraper 502 is controlled by the second drive assembly 8 to move toward the collecting tank 101, wherein when the injection needle moves to the discharge position 102, the injection needle discharges the required printing liquid from the storage cavity of the printing cylinder 2 to the discharge position 102, thereby causing the scraper 502 to scrape the printing liquid into the printing tank, and a portion of the printing liquid remains in the printing tank. Since the printing tank is not provided with a heating pad 4, the liquid printing liquid will gradually gel as the temperature decreases, thereby forming a printing layer in the printing tank; the remaining portion of the printing liquid is scraped into the collecting tank 101 after passing through the printing tank and discharged into the collecting box 9 through the discharge port 1011 for subsequent printing, thereby reducing printing costs.

[0062] Step 3: projecting the pre-processed slice image of the model to be printed onto the printing liquid in the printing tank through the objective lens 3, so that a free radical polymerization reaction occurs, thereby generating chemical cross-linking;

[0063] Specifically, as the temperature decreases, the printing liquid in the printing tank gradually gels, thereby forming a printing layer in the printing tank. At this time, the pre-processed model slice image is projected onto the printing layer through the objective lens 3, and the area illuminated by light undergoes free radical polymerization and chemical cross-linking.

[0064] Step 4: Start the first driving assembly 7 to move the mounting frame 5 away from the workbench 1, and then control the mounting frame 5 to move toward the discharge position 102 and return to the initial position through the second driving assembly 8, and start the lifting platform 6 to control the lifting block 601 to move, so that the depth of the printing slot increases;

[0065] Specifically, after a printing layer is cured, the first driving assembly 7 is started, so that the second driving assembly 8 and the mounting frame 5 are synchronously moved in a direction away from the workbench 1, so that the scraper 502 is away from the upper surface of the printing tank, and then the second driving assembly 8 is started to move the mounting frame 5 in a direction close to the discharge position 102. After the mounting frame 5 moves to above the initial position, the second driving assembly 8 and the mounting frame 5 are lowered by controlling the first driving assembly 7 until they are lowered to a point where the scraper 502 can scrape the printing liquid on the discharge position 102. At the same time, the lifting platform 6 is started to control the lifting block 601 to move so that the depth of the printing tank becomes larger, that is, the lifting block 601 is controlled to descend by a distance of a printing layer thickness so that the printing liquid can be scraped into the printing tank, thereby forming another printing layer.

[0066] It should be noted that, by controlling the second drive component 8 and the mounting frame 5 to move synchronously in a direction away from the workbench 1 through the first drive component 7, the scraper 502 does not contact the printing groove and the printing layer in the printing groove when moving toward the initial position, thereby effectively ensuring the printing quality.

[0067] Step 5: Repeat the above steps until printing is completed.

[0068] Specifically, the above steps are repeated until printing is completed, and then the gel block (composed of multiple printed layers) in the printing tank is removed, heated and cleaned, and the gel block without the photo-crosslinked part is melted to obtain a biogel 3D printed sample.

[0069] In summary, with the continuous development of 3D printing technology, more and more application fields are beginning to require printing of complex geometric shapes or high-precision models. Especially in the biomedical field, the requirements for the complex internal structure and appearance of the model are increasing. However, when faced with complex geometric shapes, traditional 3D printing technology often finds it difficult to support the stable printing of hollow, overhanging or floating structures, resulting in defects, detachment and collapse during the printing process. Based on this, by adding a temperature-sensitive phase change material to the printing liquid, a stable support can be provided for the printing of hollow, overhanging or floating structures. That is, the temperature-sensitive phase change material can undergo a phase change within a specific temperature range, and transform from a liquid to a solid or from a solid to a liquid through temperature changes. In the present disclosure, the temperature at the location of the printing slot is lower than the temperature at the location where the heating pad is installed. The printing liquid scraped into the printing slot will gradually gel due to the temperature drop, thereby forming a printing layer. After the printing layer is projected through the objective lens 3, the gelled printing liquid in the projection area undergoes irreversible chemical cross-linking. At this time, the gelled printing liquid can provide necessary support for the chemically cross-linked part, ensuring that the chemically cross-linked area can always have good stability during the printing process, and will not cause structural collapse or deformation due to gravity or other forces. At the same time, the stable support ensures the accurate printing of each layer and area during the printing process, ensuring a high consistency in printing quality.

[0070] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Within the scope of the present invention, the above embodiments or technical features in different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0071] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A scraper-type photocuring biological 3D printing device based on temperature-sensitive materials, characterized in that: include: A workbench (1), a driving mechanism, a printing cylinder (2), an objective lens (3), a heating pad (4), a mounting frame (5) and a lifting platform (6); The driving mechanism comprises a first driving assembly (7) and a second driving assembly (8), wherein the first driving assembly (7) is used to drive the second driving assembly (8) to move back and forth along the height direction of the lifting platform (6), and the second driving assembly (8) is used to drive the mounting frame (5) to move back and forth along the length direction of the workbench (1), and the mounting frame (5) is provided with a mounting plate (501) for mounting the printing cylinder (2) at one end away from the workbench (1), and a scraper (502) is provided at one end of the mounting frame (5) close to the workbench (1), and the printing cylinder (2) has a storage cavity for storing printing liquid, and the printing An injection needle connected to the storage cavity is connected to one end of the printing cylinder (2) close to the workbench (1); a through hole (103) is provided on the workbench (1); the lifting platform (6) is arranged on the lower surface of the workbench (1) and a lifting block (601) of the lifting platform (6) is partially embedded in the through hole (103) to form a printing groove; the objective lens (3) is arranged above the printing groove; the scraper (502) and the printing cylinder (2) are both provided with the heating pad (4); the temperature in the printing groove is lower than the temperature of the printing cylinder (2), so that the printing liquid scraped into the printing groove is gelled to form a printing layer.

2. A scraper-type photocuring biological 3D printing device based on temperature-sensitive materials according to claim 1, characterized in that: The invention also comprises a collecting box (9), wherein the collecting box (9) is arranged below the workbench (1), and the collecting box (9) has a storage chamber for storing printing liquid. The collecting box (9) is connected to the printing cylinder (2) via a hose (10), so that the storage chamber is in communication with the interior of the storage chamber.

3. A scraper-type photocuring biological 3D printing device based on temperature-sensitive materials according to claim 2, characterized in that: The heating pad (4) is provided on the collection box (9).

4. A scraper-type photocuring biological 3D printing device based on temperature-sensitive materials according to claim 2, characterized in that: The workbench (1) is provided with a collecting slot (101) and a discharge position (102), the collecting slot (101) and the discharge position (102) are arranged opposite to each other, and the printing slot is located between the collecting slot (101) and the discharge position (102).

5. A scraper-type photocuring biological 3D printing device based on temperature-sensitive materials according to claim 4, characterized in that: The bottom of the collecting tank (101) is provided with a discharge port (1011), and the discharge port (1011) is located directly above the opening of the collecting box (9).

6. A scraper-type photocuring biological 3D printing device based on temperature-sensitive materials according to claim 5, characterized in that: From the lower surface of the workbench (1) to the upper surface of the workbench (1), the cross-sectional area of ​​the collecting tank (101) gradually decreases.

7. A scraper-type photocuring biological 3D printing device based on temperature-sensitive materials according to claim 3, characterized in that: A plurality of heating pads (4) are installed on the workbench (1) for heating the location of the collection tank (101) and the location of the discharge position (102).

8. A scraper-type photocuring biological 3D printing method based on a temperature-sensitive material, applicable to a scraper-type photocuring biological 3D printing device based on a temperature-sensitive material according to any one of claims 1 to 7, characterized in that: The method comprises: Step 1: Start the second driving assembly (8) so that the mounting frame (5) moves from the initial position to the discharge position (102) and discharges the printing liquid from the storage chamber through the injection needle; Step 2: The scraper (502) is moved toward the collecting tank (101) by means of the second driving assembly (8), wherein part of the printing liquid located at the discharge position (102) is scraped into the printing tank, and the remaining part of the printing liquid is scraped into the collecting tank (101) after passing through the printing tank, and then discharged into the collecting box (9) through the discharge port (1011); Step 3: projecting the pre-processed slice image of the model to be printed onto the printing liquid in the printing tank through the objective lens (3), thereby causing a free radical polymerization reaction to generate chemical cross-linking; Step 4: Start the first driving assembly (7) to move the mounting frame (5) in a direction away from the workbench (1), and then control the mounting frame (5) to move in a direction close to the discharge position (102) and return to the initial position through the second driving assembly (8), and at the same time start the lifting platform (6) to control the lifting block (601) to move so that the depth of the printing slot increases; Step 5: Repeat the above steps until printing is completed.

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