A high-adhesion forming platform assembly and 3D printing forming device using the same

Abstract

The present application relates to a kind of high adhesion forming platform assembly and the 3D printing forming device using it, including forming platform assembly body and hydrophilic porous structure thin layer, hydrophilic porous structure thin layer covers on the forming end surface of forming platform assembly body;In the initial stage of printing, cell-containing photosensitive biological hydrogel is infiltrated into hydrophilic porous structure thin layer, and under the action of high light intensity selective exposure light source diffuse reflection or / and diffraction or / and scattering optical effect, it is solidified in porous and forms mechanical interlocking, to enhance the adhesion between the solidified three-dimensional building and forming end surface.The unique hydrophilic porous structure thin layer structure in the present application is combined with forming platform assembly body, forms firm mechanical interlocking, effectively prevents large-size hydrogel component from falling off in the printing process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing of biological materials, and in particular to a high-adhesion forming platform assembly and a 3D printing forming device using the same. BACKGROUND

[0002] Engineering cultured artificial tissue is an important way to meet the needs of clinical treatment, and constructing a three-dimensional tissue engineering scaffold containing cells in a 3D printing manner is an important step for engineering cultured artificial tissue.

[0003] Existing 3D printing technologies for biological materials mainly include extrusion type, droplet type and light-curing type printing.

[0004] In the prior art, the Digital Light Processor (DLP) surface projection light-curing type biological printing of Texas Instruments, USA, uses a digital micromirror device as a mask to control the on or off of the light path, realizes layer-by-layer surface exposure of the tissue engineering scaffold, and further generates a three-dimensional structure. Its advantages are: relatively high product processing precision, high light energy utilization rate, and long equipment life; the disadvantages are: first, due to the limitations of the characteristics of the digital micromirror device itself, there is a contradiction between the processing precision and the size of the processed object - high precision and large size of 6000mm 2 cannot be achieved at the same time, and large-size high-precision components can only be obtained by block-by-block splicing, thereby greatly prolonging the processing time, which will seriously affect the activity of cells in the tissue engineering scaffold containing cells, leading to printing failure; second, the digital micromirror patent license fee is very high, resulting in very expensive equipment based on it.

[0005] The technology of using a liquid crystal display (LCD) screen to replace the above-mentioned digital micromirror device as a mask to control the on or off of the light path, to realize layer-by-layer selective surface exposure of the processed object, and to further complete the corresponding three-dimensional construction appeared around 2013. The 3D printer developed by using this technology is called LCD 3D printer, and its biggest feature is low equipment cost, and there is no difficulty in processing large-size 6000mm 2 left and right components with high enough precision. The printing materials of the existing LCD 3D printer are mainly various light-curing resins.

[0006] Due to the following technical defects, the existing LCD 3D printer has not been used for three-dimensional forming of hydrogel biological materials, especially hydrogel biological materials containing cells:

[0007] 1. When printing various photocurable resins, existing LCD 3D printers can achieve good adhesion between the forming platform end face, which has been roughened by sandblasting, grinding, texture milling, and physicochemical etching, and the resin is less likely to detach. However, due to the limited adhesion between the cured hydrogel and the forming platform, large-scale workpieces in the stretching direction are prone to detachment, leading to processing failure.

[0008] 2. When printing various photocurable resins, existing LCD 3D printers are affected by the light attenuation caused by the LCD screen, resulting in an exposure light intensity that is generally around 5mW / cm². 2 The relatively long single exposure time will only reduce printing efficiency to a certain extent; however, for cell-containing bio-hydrogels, excessively long printing time will inevitably affect the biological activity of the cells—which is completely unacceptable.

[0009] 3. The temperature rise of 60-70℃ generated by the backlight LED lamp group during the printing process of existing LCD 3D printers will not significantly affect the molding and post-molding performance of various photocurable resins. However, for cell-containing bio-hydrogels, it will seriously affect the biological activity of the cells, causing them to die. 43℃ is known as the "absolute lethal temperature" of cells.

[0010] 4. Even if the platform end face is roughened, if its microstructure is unreasonable, such as the presence of a large number of closed or blind pores, gas is easily trapped in the initial stage of printing, which hinders the effective contact between the bio-hydrogel and the platform, thus making it impossible to form a strong mechanical interlock. Summary of the Invention

[0011] This invention provides a high-adhesion molding platform component and a 3D printing molding device using it. The technical problems it solves are: (1) In the prior art, the adhesion between the cell-containing bio-hydrogel and the molding platform is weak. When printing large-size or high aspect ratio components, the solidified part is easy to fall off the platform, resulting in printing failure. (2) In the prior art, the exposure light intensity is relatively weak, resulting in a long single-layer exposure time. The overall printing time exceeds the limit that cells can tolerate, and cell activity drops sharply. (3) In the prior art, the LCD backlight LED lamp assembly generates a large amount of heat when working, which can reach 60-70℃, far exceeding the cell's lethal temperature of 43℃, which will directly lead to cell death.

[0012] To solve the aforementioned technical problems, the present invention adopts the following solution:

[0013] A high-adhesion forming platform assembly, comprising a forming platform assembly body and a hydrophilic porous structure thin layer, the hydrophilic porous structure thin layer covers the forming end face of the forming platform assembly body; the cell-containing photosensitive bio-hydrogel solidifies to form a three-dimensional construct; the cell-containing photosensitive bio-hydrogel interacts with the hydrophilic porous structure thin layer and the forming end face, respectively, and the adhesion between the three-dimensional construct and the forming end face of the forming platform assembly body is enhanced through a double consolidation mechanism; wherein the first consolidation mechanism is that a part of the cell-containing photosensitive bio-hydrogel penetrates into the hydrophilic porous structure thin layer in the initial printing stage, and under the action of the diffuse reflection or / and diffraction or / and scattering optical effect of the high-intensity selective exposure light source, solidifies in the pores of the hydrophilic porous structure thin layer to form mechanical interlocking; the second consolidation mechanism is that another part of the cell-containing photosensitive bio-hydrogel penetrates through the hydrophilic porous structure thin layer to contact and wet the forming end face of the forming platform assembly body, and solidifies to form an adhesive layer between the hydrophilic porous structure thin layer and the forming end face of the forming platform assembly body.

[0014] Preferably, all the pores in the hydrophilic porous structure thin layer are open pores (also known as open cells) and are through, and the cell-containing photosensitive bio-hydrogel can penetrate into the pores and pass through a pore to enter an adjacent pore; when the forming platform assembly body is immersed in the cell-containing photosensitive bio-hydrogel, the through structure can effectively prevent gas retention, ensuring that the cell-containing photosensitive bio-hydrogel can fully penetrate into the pores, achieving the best mechanical interlocking and adhesion effect.

[0015] Preferably, the pore diameter of the hydrophilic porous structure thin layer is less than 100 microns, and the porosity is 60-80%.

[0016] Preferably, the hydrophilic porous structure thin layer is a hydrophilic rigid porous structure thin layer or a hydrophilic flexible porous structure thin layer; or / and, the porous structure of the hydrophilic porous structure thin layer is regular or irregular in shape.

[0017] Preferably, the hydrophilic porous structure thin layer is connected to the side surface of the forming platform assembly body through a fixing structure; the fixing structure includes any one of the following forms:

[0018] One of the fixing structures: the hydrophilic porous structure thin layer is provided with annular reserved holes on both sides, respectively, and a fixing rod is inserted into each annular reserved hole, the fixing rod tensioned spreads the hydrophilic porous structure thin layer on the forming end face, and the fixing rod sleeved in the reserved hole is clamped between the side surface of the forming platform assembly body and the elastic fixing clamp.

[0019] The second fixing structure: the hydrophilic porous structure thin layer is in the shape of an open box, including four peripheral vertical surfaces and a central horizontal surface, and the elastic fixing clamp is in the form of an open frame structure, the elastic fixing clamp clamps the four peripheral vertical surfaces of the hydrophilic porous structure thin layer on the side surface of the forming platform assembly body.

[0020] The third fixing structure: a slide groove is arranged on the side of the forming platform assembly body, and the hydrophilic porous structure thin layer is a rigid plate, the edge of the rigid plate is provided with a flange matched with the slide groove, and the fixing is realized by sliding insertion.

[0021] A photocuring 3D printing forming device, comprising: a high-adhesion forming platform assembly for moving a solidified three-dimensional building body in a vertical direction; a motion assembly connected with the high-adhesion forming platform assembly for driving it to move vertically accurately; a tank assembly for containing a cell-containing photosensitive biological hydrogel; a high-light-intensity selective exposure light source for generating a two-dimensional cross-sectional pattern to provide the cell-containing photosensitive biological hydrogel with light energy required for photopolymerization and solidification; and a system control unit for controlling the high-light-intensity selective exposure light source and the coordinated operation among the assemblies.

[0022] Preferably, the light intensity of the high-light-intensity selective exposure light source is 10-30 mW / cm 2 ; the high-light-intensity selective exposure light source is an LCD high-light-intensity liquid crystal display, a high-light-intensity liquid crystal display projection light machine, an OLED organic light-emitting diode display or a micro LED micro light-emitting diode display in a 405 nm wave band; when the exposure light source is an LCD high-light-intensity liquid crystal display, the backlight light source thereof adopts an integral light source or a mini LED matrix light source with a light intensity uniformity ≥ 90%; the mini LED matrix light source is a selectable area lighting light source, which can selectively light up the LED lamp beads in the corresponding area according to the shape of the two-dimensional cross-sectional pattern.

[0023] Preferably, a controllable active refrigeration assembly is further included for actively cooling the high heat generated by the high-light-intensity selective exposure light source during operation; the controllable active refrigeration assembly and the power supply of the high-light-intensity selective exposure light source are arranged outside the space requiring refrigeration.

[0024] A control method of a photocuring 3D printing forming device, comprising the following steps:

[0025] A model processing step: receiving three-dimensional model data and performing slicing processing to generate a series of two-dimensional cross-sectional pattern data;

[0026] A printing preparation step: the system control unit controls the motion assembly to drive the high-adhesion forming platform assembly to descend to the lowest position, adjusts the lower end of the high-adhesion forming platform assembly to be parallel to the release film on the bottom plane of the tank assembly; the system control unit controls the motion assembly to drive the high-adhesion forming platform assembly to ascend, so that the forming platform assembly is apart from the release film on the bottom plane of the tank assembly by a layer thickness;

[0027] The enhanced adhesion printing step is: injecting the cell-containing photosensitive bio-hydrogel into the trough assembly, and allowing it to fully infiltrate into the pores of the hydrophilic porous structure thin layer covering the forming end face of the forming platform assembly body; controlling all the high light intensity selected area exposure light sources to be turned on, and performing full-area exposure on the cell-containing photosensitive bio-hydrogel of the initial first layer to the Nth layer, N>1; allowing a part of the cell-containing photosensitive bio-hydrogel that has infiltrated into the pores of the hydrophilic porous structure thin layer to be cured under the action of the diffuse reflection or / and diffraction or / and scattering optical effect of the high light intensity selected area exposure light source, and forming a mechanical interlocking between the pores in the hydrophilic porous structure thin layer; another part of the cell-containing photosensitive bio-hydrogel passes through the hydrophilic porous structure thin layer to contact and wet the forming end face of the forming platform assembly body, and is cured to form an adhesion layer between the hydrophilic porous structure thin layer and the forming end face of the forming platform assembly body; the mechanical interlocking enhances the adhesion between the cured three-dimensional build and the forming end face;

[0028] The model entity printing step is: for each layer from the N+1th layer and the subsequent layers, the system control unit controls the high light intensity selected area exposure light source to perform selected area exposure according to the corresponding two-dimensional cross-sectional graphic data, and controls the motion assembly to lift the high-adhesion forming platform assembly layer by layer.

[0029] Preferably, the dynamic temperature control step is also included: during the printing process, when the light-cured 3D printing forming device includes a controllable active refrigeration assembly, the operation of the controllable active refrigeration assembly is controlled to maintain the temperature of the exposed area below the preset cell activity temperature threshold.

[0030] Compared with the prior art, the high-adhesion forming platform assembly and the 3D printing forming device using the same have the following beneficial effects:

[0031] (1) The unique hydrophilic porous structure thin layer structure in the present application is combined with the forming platform assembly body to form a firm mechanical interlocking, which effectively prevents large-size hydrogel components from falling off during the printing process.

[0032] (2) The hydrophilic porous structure thin layer in the present application is a through and open hole structure, and the cell-containing photosensitive bio-hydrogel not only infiltrates into the pores, but also completely penetrates the thin layer and directly reaches and wets the forming end face of the forming platform assembly body under the action of capillary action and pressure; during exposure and curing, a triple synergistic adhesion structure is thus formed: first, the mechanical interlocking of the anchor type is formed in the pores and between the pores; second, the hydrogel that penetrates the pores is cured to form a firm planar adhesion layer with the forming end face of the forming platform assembly body; third, the two form a whole rivet structure that penetrates the thin layer. This double or even triple firming mechanism of porous locking and planar adhesion is the fundamental reason for achieving super strong adhesion.

[0033] (3) The present invention uses an LCD high-intensity liquid crystal display, or a high-intensity liquid crystal display projection optical engine, or an OLED organic light-emitting diode display, or a micro LED self-emissive display as a mask to replace the digital micromirror device (DMD), which solves the contradiction between processing accuracy and processing size. Under the premise of ensuring the required processing accuracy, the printing speed is accelerated, and the forming time meets the needs of printing planar large-size cell-containing hydrogel tissue engineering scaffolds.

[0034] (4) The present invention shortens the exposure time with high light intensity and actively cools and controls the ambient temperature, thus ensuring the high survival rate of cells throughout the printing process from both time and environment dimensions.

[0035] (5) The addition of a controllable active cooling component in this invention also helps to extend the lifespan of the high-intensity selective exposure light source.

[0036] (6) The present invention uses a mini LED matrix light source with selectable lighting as the backlight source, which can extend the service life of the LCD screen and reduce the harmful temperature rise of the cell-containing hydrogel material caused by the heat generated by the backlight source, while significantly reducing the energy consumption of the light source. Attached Figure Description

[0037] Figure 1 This is a schematic diagram illustrating the basic forming principle of the photopolymerization 3D printing forming device of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure of the high adhesion forming platform component of the present invention;

[0039] Figure 3 This is a flowchart of the control method for the photopolymerization 3D printing forming device of the present invention;

[0040] Figure 4 This is a schematic diagram of the first connection method between the hydrophilic porous structure thin layer and the forming platform component body in this invention (the fixed structure is located on the forming end face).

[0041] Figure 5 This is a schematic diagram of the second connection method between the hydrophilic porous structure thin layer and the forming platform component body in this invention (the fixing structure is located on the side).

[0042] Figure 6 It corresponds to Figure 5 Main view of the structure of Embodiment 1 of the second connection method;

[0043] Figure 7 yes Figure 5 A three-dimensional structural schematic diagram of Embodiment 1 is shown;

[0044] Figure 8 yes Figure 5 Exploded view of Embodiment 1 shown;

[0045] Figure 9 This is a schematic diagram of the bottom surface of the first structure (integral type) of the elastic fixing clamp in Embodiment 1;

[0046] Figure 10 This is a schematic diagram of the bottom surface of the second structure (split type) of the elastic fixing clamp in Embodiment 1;

[0047] Figure 11 It corresponds to Figure 5 Exploded view of Embodiment 2 of the second connection method;

[0048] Figure 12 yes Figure 11 The front view of the structure of Embodiment 2 is shown.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1—High adhesion molding platform component; 10—Molding platform component body; 11—Fixing structure; 12—Molding end face; 13—Side; 2—Cell-containing photosensitive biohydrogel; 3—Release membrane; 4—Feed tank component; 5—LCD liquid crystal display; 6—Backlight source; 7—Three-dimensional construct; 8—Hydrophilic porous thin layer; 81—Pre-reserved hole; 91—Rigid round rod; 92—Elastic fixing clamp; 93—Slot; 94—Opening. Detailed Implementation

[0051] The following is combined with Figures 1 to 12 The present invention will be further described as follows:

[0052] like Figure 1 As shown, the photopolymerization 3D printing molding apparatus of the present invention mainly includes a high-adhesion molding platform assembly 1, a material tank assembly 4 containing liquid cell-containing photosensitive biohydrogel 2, a release film 3 at the bottom of the material tank assembly 4, an LCD liquid crystal display 5 as the exposure light source, and a 405nm LED backlight source 6. The high-adhesion molding platform assembly 1 includes a molding platform assembly body 10, the lower surface of which is a molding end face 12, which is horizontally parallel to the plane of the release film 3 at the bottom of the material tank assembly 4 and the upper plane of the LCD liquid crystal display 5. The high-adhesion molding platform assembly 1 can be precisely raised and lowered under the drive of the motion component. A controllable active cooling component (not shown in the figure, usually located below or around the LCD liquid crystal display 5) actively cools the LCD liquid crystal display 5.

[0053] like Figure 2As shown, the high-adhesion forming platform assembly 1 of the present application comprises a forming platform assembly body 10 and a hydrophilic porous structure thin layer 8 covering the forming end face 12 of the forming platform assembly body 10; the cell-containing photosensitive biohydrogel 2 solidifies to form a three-dimensional construct 7; the cell-containing photosensitive biohydrogel 2 interacts with the hydrophilic porous structure thin layer 8 and the forming end face 12 respectively, and the double solidification mechanisms jointly enhance the adhesion between the three-dimensional construct 7 and the forming end face 12 of the forming platform assembly body 10. Among them, the first solidification mechanism is that a part of the cell-containing photosensitive biohydrogel 2 penetrates into the hydrophilic porous structure thin layer 8 in the initial printing stage, and under the action of the diffuse reflection or / and diffraction or / and scattering optical effect of the high light intensity selective exposure light source (the meaning of "diffuse reflection or / and diffraction or / and scattering" is that there may be six modes of diffuse reflection, diffraction, scattering, diffuse reflection and diffraction, diffuse reflection and scattering, diffraction and scattering, and diffuse reflection and diffraction and scattering), solidifies to form a mechanical interlocking in the pores of the hydrophilic porous structure thin layer 8; the second solidification mechanism is that another part of the cell-containing photosensitive biohydrogel 2 penetrates through the hydrophilic porous structure thin layer 8 to contact and wet the forming end face 12 of the forming platform assembly body 10, and solidifies to form an adhesive layer between the hydrophilic porous structure thin layer 8 and the forming end face 12 of the forming platform assembly body 10.

[0054] The hydrophilic porous structure thin layer 8 is a hydrophilic rigid porous structure thin layer or a hydrophilic flexible porous structure thin layer; the thickness of the hydrophilic porous structure thin layer is in the order of hundreds of microns; the porous structure can be regular or irregular, with a diameter less than 100 microns and a porosity of 60-80%, and the pores are connected to each other, so that the hydrogel can penetrate into the pores.

[0055] In the present application, the porous structure of the hydrophilic porous structure thin layer 8 is preferably an open pore network with interconnecting pores. In the initial printing stage, when the high-adhesion forming platform assembly 1 is immersed in the cell-containing photosensitive biohydrogel 2, the interconnecting structure provides an effective escape channel for the air originally in the pores, ensuring that the hydrogel can completely fill the porous structure and avoiding the loss of contact area and solidification defects caused by gas retention. This enables the hydrogel to fully embed and penetrate the hydrophilic porous structure thin layer 8 during subsequent exposure and solidification, forming a complete and firm three-dimensional mechanical interlocking structure, thereby greatly enhancing the initial adhesion and laying a foundation for the successful printing of large-size or high-aspect-ratio components. Figure 2 The arrow in the figure represents the escape of gas from the hydrophilic porous structure thin layer 8 through the open pore network with interconnecting pores.

[0056] In this invention, the liquid cell-containing photosensitive bio-hydrogel 2, under capillary action, first fills the pores of the hydrophilic porous structure thin layer 8, and then reaches and contacts the forming end face 12 of the forming platform component body 10 through the interconnected pores. After exposure and curing, the cured cell-containing photosensitive bio-hydrogel 2 not only forms a mechanically interlocking region within the pores, but also forms a dense adhesive layer at the interface between the hydrophilic porous structure thin layer 8 and the forming end face 12. The mechanically interlocking region and the adhesive layer together constitute a strong whole that cannot be easily peeled off.

[0057] The porosity of the hydrophilic porous thin layer of this invention is set at 60-80%, a range crucial for achieving high-strength adhesion and successful printing. Its advantages are: First, the high porosity provides maximum space for the cured hydrogel, forming a strong three-dimensional mechanical interlocking structure, resulting in adhesion far exceeding that of planar bonding; Second, the retained 20-40% solid skeleton ensures the structural strength and integrity of the thin layer itself, effectively transferring and dispersing stress; Third, the combination of interconnected pores and high porosity ensures rapid penetration and complete filling of the pores by the bio-hydrogel, while thoroughly expelling internal gas and avoiding adhesion defects; Fourth, optically, this porosity range achieves an optimal balance, ensuring sufficient light penetration to cure the underlying hydrogel while utilizing the porous structure to induce sufficient diffuse reflection and scattering effects, ensuring light reaches deep into the pores, allowing the embedded hydrogel to solidify as a whole, thereby achieving the highest adhesion reliability.

[0058] like Figure 3 As shown, the control method of the photopolymerization 3D printing forming device of the present invention includes the following steps:

[0059] 1. Model processing steps: Receive 3D model data and perform slicing processing to generate a series of 2D cross-sectional graphic data.

[0060] 2. Printing preparation steps: The system control unit controls the motion component to drive the high adhesion forming platform component 1 to descend, so that the forming platform component 1 is one layer thick away from the bottom of the material tank component 4.

[0061] 3. Reinforced adhesion printing step: inject cell-containing photosensitive biohydrogel 2 into the vat assembly 4 and allow it to fully infiltrate into the pores of the thin layer of hydrophilic porous structure 8 covering the forming end face 12 of the forming platform assembly body 10. Turn on all the high light intensity selected area exposure light sources and expose the cell-containing photosensitive biohydrogel in the initial first layer to the Nth layer, N > 1, to full area light. A portion of the cell-containing photosensitive biohydrogel that has infiltrated into the pores of the thin layer of hydrophilic porous structure 8 is solidified in the pores of the thin layer of hydrophilic porous structure 8 under the action of the high light intensity selected area exposure light source diffuse reflection or / and diffraction or / and scattering optical effects to form a mechanical interlock. Another portion of the cell-containing photosensitive biohydrogel 2 passes through the thin layer of hydrophilic porous structure 8 to contact and wet the forming end face 12 of the forming platform assembly body and solidifies to form an adhesive layer between the thin layer of hydrophilic porous structure 8 and the forming end face 12 of the forming platform assembly body 10. The mechanical interlock enhances the adhesion between the solidified three-dimensional build 7 and the forming end face 12.

[0062] 4. Model entity printing step: at the beginning of printing, the high-adhesion forming platform assembly 1 is immersed in the liquid cell-containing photosensitive biohydrogel 2, leaving a layer-thickness gap (several microns) between its lower surface and the release film 3. The light emitted by the backlight light source 6 is converted by the LCD liquid crystal display 5 into a two-dimensional pattern of light and dark areas, which is projected through the release film 3 onto the horizontal thin layer of cell-containing photosensitive biohydrogel 2 filling the above-mentioned gap. The cell-containing photosensitive biohydrogel 2 irradiated by bright light is solidified by photopolymerization and adheres to the lower plane of the high-adhesion forming platform assembly 1, completing a printing cycle. The irradiated area is photocured, and the three-dimensional build 7 adheres to the high-adhesion forming platform assembly 1, completing a layer of printing.

[0063] The high-adhesion forming platform assembly 1 is moved upward by a layer-thickness distance, and the cell-containing photosensitive biohydrogel 2 fills the plane space left by the upward movement of the high-adhesion forming platform assembly 1. The backlight light source 6 of the 405-nanometer light-emitting diode (LED) light group is turned on again, and the light is converted by the LCD liquid crystal display 5 into another two-dimensional pattern of light and dark areas, which is projected through the release film 3 onto the horizontal thin layer of cell-containing photosensitive biohydrogel 2 filling the above-mentioned gap. The cell-containing photosensitive biohydrogel 2 irradiated by bright light is solidified by photopolymerization and adheres to the surface of the layer that has been solidified in the previous cycle, completing the second printing cycle.

[0064] After repeating this process several times, a three-dimensional build 7 formed of solidified cell-containing photosensitive biohydrogel 2 is stacked on the lower plane of the high-adhesion forming platform assembly 1.

[0065] In summary, for the N+1th layer and subsequent layers, based on the corresponding two-dimensional cross-sectional graphic data, the system control unit controls the high-intensity selective exposure light source to perform selective exposure, solidifies the cell-containing photosensitive biohydrogel layer by layer, and controls the motion components to lift the high-adhesion forming platform component 1 layer by layer.

[0066] In the initial layers of the printing process, the backlight source 6 of the 405nm LED light-emitting diode lamp group is fully lit, allowing each layer of cell-containing photosensitive bio-hydrogel 2 to solidify due to photopolymerization, thus firmly adhering to the bottom of the high-adhesion forming platform assembly 1. Based on the amount of cell-containing bio-hydrogel required for the specific printed 3D tissue engineering scaffold, the minimum size of the high-adhesion forming platform assembly 1 and the material tank assembly 4 is selected to minimize the consumption of expensive cell-containing bio-hydrogel.

[0067] When cost permits, a 405nm high-intensity liquid crystal display projection engine can be used to replace the high-intensity LCD display, thus obtaining another different embodiment. Similarly, when cost permits, a 405nm OLED organic light-emitting diode display or a 405nm micro LED micro light-emitting diode display can also be used as the high-intensity selective exposure light source. Since neither of these types of displays requires a backlight source, they can be directly used to replace the high-intensity LCD display to obtain two other different embodiments.

[0068] The technical problem solved by the aforementioned hydrophilic porous structure thin layer 8 is that the printed material easily detaches from the forming platform assembly body 10. However, adding the hydrophilic porous structure thin layer 8 also brings new technical problems: how to fix the hydrophilic porous structure thin layer 8 to the forming platform assembly body 10. Therefore, the present invention also includes a fixing structure 11 to connect the hydrophilic porous structure thin layer 8 to the forming platform assembly body 10 to form a highly adhesive forming platform assembly 1.

[0069] The fixing structure 11 can take different forms, including but not limited to mechanical fixing, magnetic fixing, negative pressure adsorption fixing, and adhesive fixing.

[0070] like Figure 4 As shown, a hydrophilic porous thin layer 8 covers the forming end face 12 of the forming platform assembly body 10, which is typically the bottom surface of the forming platform assembly body 10. The fixing structure 11 for both is located on the forming end face 12 of the forming platform assembly body 10, and the fixing structure 11 can be a mechanical clamp, magnetic adsorption, or negative pressure adsorption, etc.

[0071] like Figure 5, one of the fixing structures 11 is located on the side surface 13 of the shaped platform assembly body 10, and the other one is located on the shaped end surface 12 of the shaped platform assembly body 10. At this time, the fixing structure 11 can also be a mechanical clamp, magnetic adsorption or negative pressure adsorption, etc.

[0072] Both of the fixing structures 11 can be located on the side surface 13 and the shaped end surface 12 of the high-adhesion shaped platform assembly 1 at the same time.

[0073] As shown in Figures 6-10 , one of the fixing structures is that a flexible hydrophilic porous structure thin layer 8 is covered on the lower plane or the shaped end surface 12 of the shaped platform assembly body 10, and a hard round rod 91 for flattening the flexible hydrophilic porous structure thin layer 8 is inserted into the reserved hole 81 at both ends of the flexible hydrophilic porous structure thin layer 8. The elastic fixing clamp 92 tightens and spreads the flexible hydrophilic porous structure thin layer 8 with the hard round rod 91 inserted, and clamps it tightly on the shaped end surface 12 of the shaped platform assembly body 10.

[0074] The hard round rod 91 with the reserved hole 81 is clamped between the side surface 13 of the shaped platform assembly body 10 and the clamping groove 93 of the elastic fixing clamp 92. There can also be an extension structure: the elastic sheet on both sides of the elastic fixing clamp 92, and the direct hydrophilic porous structure thin layer 8 is clamped between the side surface 13 of the shaped platform assembly body 10 and the elastic sheet, which can omit the use of the hard round rod 91.

[0075] As shown in Figure 9 , the elastic fixing clamp 92 is two groups, and when the two groups of elastic fixing clamps 92 are an integral part, an opening 94 is formed for the hydrophilic porous structure thin layer 8 to contact the cell-containing photosensitive biological hydrogel 2.

[0076] As shown in Figure 10 , the elastic fixing clamp 92 is two groups, and is separated from each other, and the gap between the two is for the hydrophilic porous structure thin layer 8 to contact the cell-containing photosensitive biological hydrogel 2.

[0077] As shown in Figures 11 to 12 , the second fixing structure is that the hydrophilic porous structure thin layer 8 is in the shape of an open box, including four vertical peripheral surfaces and a central horizontal surface, and the elastic fixing clamp 92 is in the shape of an open frame structure, which clamps the four vertical peripheral surfaces of the hydrophilic porous structure thin layer 8 on the side surface 13 of the shaped platform assembly body 10.

[0078] In addition, the following types of fixing structures are also included:

[0079] The third fixing structure uses a snap-fit ​​groove. This solution is mainly suitable for rigid hydrophilic porous thin layers 8, such as porous ceramic sheets. A ring-shaped "T" groove is machined on the side 13 of the forming platform assembly body 10. The edges of the rigid hydrophilic porous thin layer 8 are correspondingly machined with "T" shaped flanges that can be embedded in the groove. During installation, the rigid hydrophilic porous thin layer 8 is aligned with the groove and pushed in. An elastic snap-fit ​​can be designed to lock it in place at the end position, ensuring a very secure fixation.

[0080] The high-adhesion forming platform component 1 can be a single component or can consist of multiple components with different forming end face sizes to accommodate different printing volume requirements.

[0081] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A high adhesion forming platform assembly characterized by: The high-adhesion forming platform assembly comprises a forming platform assembly body (10) and a hydrophilic porous structure thin layer (8) covering the forming end surface (12) of the forming platform assembly body (10); the three-dimensional construct (7) is formed after the cell-containing photosensitive bio-hydrogel (2) is solidified; the cell-containing photosensitive bio-hydrogel (2) interacts with the hydrophilic porous structure thin layer (8) and the forming end surface (12) respectively, and the adhesion between the three-dimensional construct (7) and the forming end surface (12) of the forming platform assembly body is enhanced through the double solidification mechanisms; The first solidification mechanism is that a part of the cell-containing photosensitive bio-hydrogel (2) penetrates into the hydrophilic porous structure thin layer (8) in the initial printing stage, and is solidified to form mechanical interlocking in the pores of the hydrophilic porous structure thin layer (8) under the action of the diffuse reflection or / and diffraction or / and scattering optical effect of the high-intensity selective exposure light source; The second solidification mechanism is that another part of the cell-containing photosensitive bio-hydrogel (2) contacts and wets the forming end surface (12) of the forming platform assembly body (10) through the hydrophilic porous structure thin layer (8), and forms an adhesive layer between the hydrophilic porous structure thin layer (8) and the forming end surface (12) of the forming platform assembly body (10); The pores in the hydrophilic porous structure thin layer (8) are all open pores, the porous structure of the hydrophilic porous structure thin layer (8) is an open pore network, gas is discharged from the hydrophilic porous structure thin layer (8) through the open pore network, the cell-containing photosensitive bio-hydrogel (2) can penetrate into the pores and enter adjacent pores through a pore, and when the forming platform assembly body (10) is immersed in the cell-containing photosensitive bio-hydrogel (2), the through structure can effectively prevent gas retention, so that the cell-containing photosensitive bio-hydrogel (2) can fully penetrate into the pores, and the best mechanical interlocking and adhesion effect is achieved; The pore diameter of the hydrophilic porous structure thin layer (8) is less than 100 microns, and the porosity is 60-80%.

2. The high-adhesion forming table assembly of claim 1, wherein: The hydrophilic porous structure thin layer (8) is a hydrophilic rigid porous structure thin layer or a hydrophilic flexible porous structure thin layer; or / and, the porous structure of the hydrophilic porous structure thin layer (8) is regular or irregular.

3. The high-adhesion forming platform assembly according to claim 1 or 2, characterized in that: The hydrophilic porous structure thin layer (8) is connected to the side surface (13) of the forming platform assembly body (10) through a fixing structure (11); The fixing structure (11) comprises any one of the following forms: One of the fixing structures: the hydrophilic porous structure thin layer (8) is provided with a ring-shaped reserved hole (81) on each side, a fixing rod is inserted into each ring-shaped reserved hole (81), the fixing rod tensioned spreads the hydrophilic porous structure thin layer (8) on the forming end surface (12), and the fixing rod sleeved in the reserved hole (81) is clamped between the side surface (13) of the forming platform assembly body (10) and the elastic fixing clamp (92). The second fixing structure: the hydrophilic porous structure thin layer (8) is in the shape of an open box, including four vertical peripheral surfaces and a central horizontal surface, and the elastic fixing clamp (92) is in the shape of an open frame, the four vertical peripheral surfaces of the hydrophilic porous structure thin layer (8) being clamped on the side surface (13) of the forming platform assembly body (10) by the elastic fixing clamp (92); The third fixing structure: the side surface (13) of the forming platform assembly body (10) is provided with a sliding groove, and the hydrophilic porous structure thin layer (8) is a rigid plate, the edge of the rigid plate being provided with a flange matched with the sliding groove, and the fixing is realized by sliding insertion.

4. A photocured 3D printing forming apparatus characterized by: Comprise: The high-adhesion forming platform assembly (1) according to any one of claims 1-3, used for moving the solidified three-dimensional building (7) in the vertical direction; A motion assembly connected with the high-adhesion forming platform assembly (1) and used for driving the high-adhesion forming platform assembly (1) to move vertically accurately; A tank assembly (4) used for containing the cell-containing photosensitive biological hydrogel (2); The high light intensity selective exposure light source is used to generate two-dimensional cross-sectional patterns and provide light energy required for photopolymerization and solidification of the cell-containing photosensitive biological hydrogel (2); the exit light intensity of the high light intensity selective exposure light source is between 10-30 mW / cm 2 . A system control unit used for controlling the high-intensity selective exposure light source and the cooperative operation among the assemblies.

5. The photocuring 3D printing forming device according to claim 4, characterized in that: The high-intensity selective exposure light source is an LCD high-intensity liquid crystal display, a high-intensity liquid crystal display projection light machine, an OLED organic light-emitting diode display or a micro LED micro light-emitting diode display with a wavelength of 405 nm; When the exposure light source is the LCD high-intensity liquid crystal display, the backlight light source adopts an integral light source or a mini LED matrix light source with a light intensity uniformity of ≥90%; the mini LED matrix light source is a selectable area lighting light source, which can selectively light the LED lamp beads in the corresponding area according to the shape of the two-dimensional cross-sectional figure.

6. Photocuring 3D printing forming apparatus according to claim 4 or 5, characterized in that: Further comprising a controllable active refrigeration assembly used for actively cooling the high heat generated when the high-intensity selective exposure light source operates; The controllable active refrigeration assembly and the power supply of the high-intensity selective exposure light source are arranged outside the space requiring refrigeration.

7. A control method of the photocuring 3D printing forming apparatus according to claim 4 or 5 or 6, characterized by: Comprise the following steps: A model processing step: receiving three-dimensional model data and performing slicing processing to generate a series of two-dimensional cross-sectional figure data; A printing preparation step: the system control unit controls the motion assembly to drive the high-adhesion forming platform assembly (1) to descend to the lowest position, adjusts the lower end of the high-adhesion forming platform assembly (1) so that it is parallel to the release film (3) on the bottom plane of the tank assembly (4), and controls the motion assembly to drive the high-adhesion forming platform assembly (1) to ascend so that the forming platform assembly (1) is away from the release film (3) on the bottom plane of the tank assembly (4) by a layer thickness. Enhanced adhesion printing step: inject cell-containing photosensitive biohydrogel (2) into the trough assembly (4), and wait for it to fully infiltrate into the pores of the hydrophilic porous structure thin layer (8) covering the forming end face (12) of the forming platform assembly body (10); control all the high light intensity selected area exposure light sources to be turned on, and perform full-area exposure on the cell-containing photosensitive biohydrogel (2) of the first layer to the Nth layer, N>1; part of the cell-containing photosensitive biohydrogel (2) that has infiltrated into the pores of the hydrophilic porous structure thin layer (8) is cured under the action of the diffuse reflection or / and diffraction or / and scattering optical effect of the high light intensity selected area exposure light source, and forms mechanical interlocking with the pores in the hydrophilic porous structure thin layer (8); another part of the cell-containing photosensitive biohydrogel (2) contacts and wets the forming end face (12) of the forming platform assembly body through the hydrophilic porous structure thin layer (8), and is cured to form an adhesion layer between the hydrophilic porous structure thin layer (8) and the forming end face (12) of the forming platform assembly body (10); the mechanical interlocking enhances the adhesion between the cured three-dimensional build (7) and the forming end face (12); Model entity printing step: for each layer from the N+1th layer and onwards, the system control unit controls the high light intensity selected area exposure light source to perform selected area exposure according to the corresponding two-dimensional cross-sectional graphic data, and controls the motion assembly to lift the high-adhesion forming platform assembly (1) layer by layer. 8.The method of controlling a photocuring 3D printing forming apparatus according to claim 7, characterized in that: It also includes a dynamic temperature control step: during the printing process, when the photocuring 3D printing forming device includes a controllable active refrigeration assembly, control its operation to maintain the temperature of the exposure area below the preset cell activity temperature threshold.

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