A high-precision dilute ink direct-write 3D printing method and apparatus based on a temperature-controlled freezing platform

Abstract

This invention relates to the field of ink-to-ink 3D printing methods, and particularly to a high-precision dilute ink-to-ink 3D printing method and apparatus based on a temperature-controlled freezing platform. It includes a copper plate, a platform top cover, a platform bottom shell, an insulation layer, a liquid nitrogen chamber, a temperature-controlled heating plate, a digital display temperature control module, and a thermocouple temperature measuring device. The steps are as follows: Constructing a temperature-controlled freezing platform; assembling the copper plate, platform top cover, platform bottom shell, insulation layer, liquid nitrogen chamber, temperature-controlled heating plate, digital display temperature control module, and thermocouple temperature measuring device to form a temperature-controlled freezing platform; preparing dilute solution raw materials; mixing sodium alginate and deionized water at a certain mass ratio and stirring; introducing liquid nitrogen into the constructed temperature-controlled freezing platform while simultaneously turning on the temperature-controlled heating plate, adjusting the copper plate on the temperature-controlled freezing platform to a certain temperature; loading the prepared dilute solution into the syringe of the ink-to-ink 3D printer, and printing the pattern on the copper plate on the temperature-controlled freezing platform at the set temperature; the dilute solution used is a solution without shear-thinning properties, and the printed product pattern is a high-resolution pattern.

Description

Technical Field

[0001] This invention relates to the field of ink direct writing 3D printing methods, and in particular to a high-precision dilute ink direct writing 3D printing method based on a temperature-controlled freezing platform. Background Technology

[0002] Direct-write ink (DIW) 3D printing builds three-dimensional objects layer by layer using inkjet printing, offering advantages such as high precision, multi-material printing, and the ability to manufacture complex structures. However, traditional inks used in DIW 3D printing are typically viscous and exhibit shear-thinning properties, which limits the selection and proportioning of ink materials and makes them difficult to store. Furthermore, the relatively dense texture of viscous inks can easily clog the printing nozzles during the DIW process, affecting the continuity of the printing process. Therefore, a major challenge for DIW 3D printing is to develop a method that can utilize dilute solutions to complete the printing process.

[0003] The dilute solution direct-write 3D printing method based on a temperature-controlled freezing platform not only enables the printing of dilute solutions but also provides in-situ directional freezing for water-based inks that do not exhibit significant shear-thinning properties. Printable water-based dilute ink is extruded through the nozzle of the ink-to-ink 3D printer under the action of an air pump and rapidly solidifies upon contact with a low-temperature copper plate, causing the water in the ink to instantly freeze into ice crystals that grow upwards. During the subsequent freeze-drying process, these ice crystals sublimate and form directional biomimetic pore structures in situ. This technology significantly improves the fidelity of the ink and the integrity of the printed structure, providing a feasible solution for the design of customized structural materials in 3D printing.

[0004] To further realize the direct-write 3D printing of patterns using dilute solutions, in-situ directional cryogenic 3D printing has emerged. Currently reported in-situ directional cryogenic 3D printing methods typically involve placing a frozen copper plate directly onto the 3D printer stage for model printing. This method is cumbersome and makes it difficult to control the temperature of the copper plate within a specific range. While commercially available temperature-controlled cryogenic platforms can achieve some temperature control, they are expensive and large in size, making them unsuitable for laboratory desktop ink-write 3D printing equipment in terms of both economy and practicality.

[0005] Therefore, how to build a temperature-controlled freezing platform that is both economical and practical, realize the in-situ directional freezing-assisted ink direct writing 3D printing method, and apply it to the printing of dilute solutions remains a challenge. Summary of the Invention

[0006] The purpose of this invention is to address the problems existing in the background technology by proposing a high-precision dilute ink direct-write 3D printing method based on a temperature-controlled freezing platform. The temperature-controlled freezing platform proposed in this invention has a novel construction method, simple process, and low cost. It can perform high-resolution pattern formation for ink direct-write 3D printing of dilute solutions that do not have shear-thinning properties, and has important application value for the development of dilute solution printing methods.

[0007] The technical solution of the present invention:

[0008] The first aspect of the present invention provides a temperature-controlled refrigeration platform device comprising a copper plate, a platform top cover, a platform bottom shell, an insulation layer, a liquid nitrogen chamber, a temperature-controlled heating plate, a digital display temperature control module, and a thermocouple temperature measuring device, wherein:

[0009] The copper plate is placed in the round hole on the top cover of the platform, and the bottom surface of the copper plate is engaged with the flange around the round hole on the bottom surface of the platform top cover.

[0010] The platform top cover is installed to the platform bottom shell via L-shaped pins at the four corners;

[0011] The insulation layer is filled into the bottom shell of the platform, and a groove is opened in its central area to hold the liquid nitrogen tank;

[0012] The liquid nitrogen chamber is placed in a groove in the central area of ​​the insulation layer;

[0013] The adhesive backing of the temperature-controlled heating plate is bonded to the lower surface of the copper plate;

[0014] The digital display temperature control module is connected to the temperature control heating plate via wires;

[0015] The temperature sensing lead of the thermocouple temperature measuring device is connected to the copper plate; the temperature control platform can regulate the temperature between -100℃ and 0℃.

[0016] Preferably, the copper plate has a diameter of 60mm and a thickness of 2mm, and has good thermal conductivity, and is used to support the pattern model printed by the ink direct writing 3D printer.

[0017] Preferably, the temperature-controlled heating plate can achieve precise heating temperature control between 0-100℃ by connecting to a digital display control module; the temperature-controlled freezing platform can complete the adjustment within a certain temperature range when liquid nitrogen is introduced.

[0018] Preferably, the liquid nitrogen chamber is a stainless steel bowl with a frustum-shaped exterior, a top opening diameter of 60mm, a bottom diameter of 40mm, a height of 28mm, and a wall thickness of 1mm; it is used to hold liquid nitrogen introduced into the temperature-controlled freezing platform to achieve a continuous low-temperature environment in the temperature-controlled freezing platform.

[0019] Preferably, the insulation layer is aluminum silicate insulation cotton, which is filled into the temperature-controlled freezing platform to achieve the continuous low-temperature freezing effect of the temperature-controlled freezing platform.

[0020] Preferably, the platform bottom shell is made of PLA material by 3D printing. The platform bottom shell is 120mm long, 75mm wide, 38mm high, and 1mm thick. The side opening facilitates the input of liquid nitrogen.

[0021] The platform top cover is 3D printed from PLA material. It measures 120mm in length, 75mm in width, and 2mm in thickness. A 60mm diameter circular hole is located at the top, and a 1mm thick flange is designed around the bottom hole to support the copper plate. L-shaped pins are located at the four corners of the bottom surface of the platform top cover to facilitate installation between the top cover and the platform base.

[0022] A second aspect of the present invention provides a high-precision dilute ink direct-write 3D printing method based on a temperature-controlled freezing platform, comprising the following specific steps:

[0023] S1. Construct a temperature-controlled freezing platform; Assemble the copper plate, platform top cover, platform bottom shell, insulation layer, liquid nitrogen tank, temperature-controlled heating plate, digital display temperature control module, and thermocouple temperature measuring device in a certain order to form a temperature-controlled freezing platform.

[0024] S2. Prepare raw materials for the dilute solution; mix sodium alginate and deionized water in a certain mass ratio and stir.

[0025] S3. Pour liquid nitrogen into the temperature-controlled freezing platform built in step S1, and at the same time turn on the temperature-controlled heating plate to adjust the copper plate on the temperature-controlled freezing platform to a certain temperature.

[0026] S4. The dilute solution prepared in step S2 is loaded into the syringe of the ink direct writing 3D printer, and the pattern is printed on the copper plate of the temperature-controlled freezing platform where the temperature is set in step S3.

[0027] Preferably, in step S2, sodium alginate and deionized water are mixed at a mass ratio of 50:1, stirred with a magnetic stirrer for 1 to 12 hours to ensure thorough mixing, or manually ground for 20 minutes to 2 hours, or stirred for 10 minutes to 1 hour and then degassed for 10 minutes to 1 hour using a stirrer-deaerator.

[0028] Preferably, in step S3, the adhesive backing of the temperature-controlled heating plate is attached to the bottom surface of the copper plate. When a certain amount of liquid nitrogen is introduced and the copper plate reaches a certain low temperature, the temperature-controlled heating plate is turned on and heated to a certain temperature. When the reading of the thermocouple temperature measuring device is lower than the target temperature, the introduction of liquid nitrogen is stopped and the temperature of the temperature-controlled heating plate is increased. When the reading of the thermocouple temperature measuring device is higher than the target temperature, liquid nitrogen is introduced again and the temperature of the temperature-controlled heating plate is decreased. This allows the temperature of the copper plate to be controlled between -100℃ and -0℃.

[0029] Preferably, when additive manufacturing is used in step S4:

[0030] The raw materials in step S2 are loaded into an ink direct writing 3D printer as printing ink. In-situ freezing technology is used as an aid to design and print dilute solution model patterns on a cooled copper plate.

[0031] Among them, the nozzle diameter of the ink direct writing 3D printer is 10-1000μm, the printing pressure is 5-100psi, the needle speed is 1-50mm / s, the layer height is consistent with the nozzle diameter, and the printed shape and structure are modeled by 3D software and sliced ​​and imported into the printer system for use.

[0032] The shapes of dilute solution models printed by the S4 ink-to-write 3D printer can be customized, including grid, snake, honeycomb, or interdigitated shapes.

[0033] Preferably, the dilute solution does not have shear-thinning properties, but high-resolution pattern forming can still be achieved using ink-to-ink 3D printing.

[0034] Compared with the prior art, the present invention has the following beneficial technical effects:

[0035] 1. Thinner ink system and high-resolution pattern formation: Breaking the conventional view that ink used in ink-to-ink 3D printing should have shear-thinning properties, high-resolution ink-to-ink 3D printing pattern formation can still be achieved using thinner inks that do not have shear-thinning properties.

[0036] 2. Simplified process and low cost: This invention provides a method for building a temperature-controlled freezing platform, which is simple in process, low in cost, and suitable for mass production.

[0037] 3. Adjustable freezing platform temperature: By controlling the amount of liquid nitrogen introduced and the heating temperature of the temperature-controlled heating plate, the temperature of the copper plate can be adjusted within a certain range.

[0038] 4. Optimized microstructure: Directional freezing technology can be used to prepare microporous structures in dilute solutions, providing a new approach to the formation of porous microstructures.

[0039] 5. Adjustable macroscopic geometry: The dilute solution model pattern prepared by the method of this invention has an adjustable macroscopic structure, which can meet user needs through personalized design and be effectively applied in practice.

[0040] 6. Wide applicability: The dilute solution direct writing 3D printing method of the temperature-controlled freezing platform proposed in this invention is also applicable to the preparation of microporous aerogels. Attached Figure Description

[0041] Figure 1 This is a structural diagram of a temperature-controlled refrigeration platform.

[0042] Figure 2 Cross-sectional view of a temperature-controlled refrigeration platform;

[0043] Figure 3 Temperature control flow chart for a temperature-controlled refrigeration platform;

[0044] Figure 4 Rheological properties test diagram of sodium alginate dilute ink;

[0045] Figure 5 Comparison of printing effects of sodium alginate dilute ink with and without a temperature-controlled freezing platform;

[0046] Figure 6 Microscopic SEM image of the cross-section of a sample printed with sodium alginate dilute ink.

[0047] Reference numerals in the attached diagram: 1. Copper plate; 2. Platform top cover; 3. Platform bottom shell; 4. Insulation layer; 5. Liquid nitrogen chamber; 6. Temperature control heating plate; 7. Digital display temperature control module; 8. Thermocouple temperature measuring device. Detailed Implementation

[0048] Example 1

[0049] This embodiment provides a temperature-controlled refrigeration platform, including a copper plate 1, a platform top cover 2, a platform bottom shell 3, an insulation layer 4, a liquid nitrogen chamber 5, a temperature-controlled heating plate 6, a digital display temperature control module 7, and a thermocouple temperature measuring device 8, wherein:

[0050] Copper plate 1 is placed in the round hole on the platform top cover 2, and the bottom surface of copper plate 1 is engaged with the flange around the round hole on the bottom surface of the platform top cover 2.

[0051] The platform top cover 2 is installed to the platform bottom shell 3 via L-shaped pins at the four corners;

[0052] The insulation layer 4 is filled into the bottom shell 3 of the platform, and a groove is opened in its central area to support the liquid nitrogen tank 5.

[0053] The liquid nitrogen chamber 5 is placed in the groove in the central area of ​​the insulation layer 4.

[0054] The adhesive backing of the temperature-controlled heating plate 6 is bonded to the lower surface of the copper plate 1.

[0055] The digital display temperature control module 7 is connected to the temperature control heating plate 6 via wires.

[0056] The temperature measuring lead of the thermocouple temperature measuring device 8 is connected to the copper plate 1; the temperature control platform can regulate the temperature between -100℃ and 0℃.

[0057] The temperature-controlled freezing platform that has been built is as follows Figure 1 As shown, the installation relationship of the various structures inside the temperature-controlled refrigeration platform is as follows: Figure 2 As shown in the sectional view.

[0058] Example 2

[0059] This embodiment provides a temperature control method for a temperature-controlled freezing platform. The temperature control platform built in Embodiment 1 is adjusted, including both heating and cooling adjustments. The specific operation is as follows:

[0060] 1. Heating operation: When the temperature of copper plate 1 on the temperature-controlled freezing platform is lower than the target temperature, the flow of liquid nitrogen into the temperature-controlled freezing platform should be stopped, and the temperature of copper plate 1 should be raised by the temperature-controlled heating plate 6 through the digital display temperature control module 7.

[0061] 2. Cooling operation: When the temperature of copper plate 1 on the temperature-controlled freezing platform is higher than the target temperature, liquid nitrogen should be introduced into the temperature-controlled freezing platform, and the temperature-controlled heating plate 6 should be controlled by the digital display temperature control module 7 to reduce the temperature of copper plate 1.

[0062] The specific temperature control process for the temperature-controlled refrigeration platform is as follows: Figure 3 As shown.

[0063] Example 3

[0064] This embodiment provides a high-precision dilute ink direct-write 3D printing method based on a temperature-controlled freezing platform. The specific implementation steps are as follows:

[0065] 1. Preparation of dilute solution ink: Mix sodium alginate and deionized water at a mass ratio of 50:1, stir for 1 hour using a stirrer-deaerator, and then deaerate for 30 minutes.

[0066] 2. Direct ink-to-ink 3D printing without using a temperature-controlled freezing platform: The prepared dilute solution ink is loaded into the ink-to-ink 3D printer, the printer nozzle diameter is set to 15μm, the printing pressure is 10psi, and the needle speed is 20mm / s. The dilute solution model pattern is designed and printed on a copper plate 1 at room temperature.

[0067] Example 4

[0068] This embodiment provides a high-precision dilute ink direct-write 3D printing method based on a temperature-controlled freezing platform. Temperature control is performed using the temperature-controlled freezing platform from Embodiment 1 and the temperature adjustment method from Embodiment 2. The specific implementation steps are as follows:

[0069] 1. Construct a temperature-controlled freezing platform: Assemble the copper plate 1, platform top cover 2, platform bottom shell 3, insulation layer 4, liquid nitrogen chamber 5, temperature-controlled heating plate 6, digital display temperature control module 7, and thermocouple temperature measuring device 8 according to Example 1 to form a temperature-controlled freezing platform.

[0070] 2. Preparation of dilute solution ink: Sodium alginate and deionized water are mixed at a mass ratio of 50:1. The mixture is stirred for 1 hour using a stirrer-deaerator, and then deaerated for 30 minutes.

[0071] 3. Adjusting the temperature of the temperature-controlled freezing platform: When a certain amount of liquid nitrogen is introduced and the copper plate 1 reaches a certain low temperature, the temperature-controlled heating plate 6 is turned on and heated to a certain temperature. When the reading of the thermocouple temperature measuring device 8 is lower than the target temperature, the introduction of liquid nitrogen is stopped and the temperature of the temperature-controlled heating plate 6 is increased. When the reading of the thermocouple temperature measuring device 8 is higher than the target temperature, liquid nitrogen is introduced again and the temperature of the temperature-controlled heating plate 6 is decreased, and the temperature of the copper plate 1 on the temperature-controlled freezing platform is adjusted to 0℃.

[0072] 4. Perform in-situ directional cryogenic assisted ink direct writing 3D printing: Load the prepared dilute solution ink into the ink direct writing 3D printer, set the printer nozzle diameter to 15μm, printing pressure to 10psi, and nozzle speed to 20mm / s, and use in-situ cryogenic technology as an aid to design and print the dilute solution model pattern on the cooled copper plate 1.

[0073] 5. Freeze-dry the printed dilute solution model pattern for 12 hours at a temperature of -50℃.

[0074] 6. Obtain lightweight materials with porous microstructures, which can be used for the manufacture of lightweight structural devices and microporous devices.

[0075] Example 5

[0076] This embodiment provides a high-precision dilute ink direct-write 3D printing method based on a temperature-controlled freezing platform. Temperature control is performed using the temperature-controlled freezing platform from Embodiment 1 and the temperature adjustment method from Embodiment 2. The specific implementation steps are as follows:

[0077] 1. Construct a temperature-controlled freezing platform: Assemble the copper plate 1, platform top cover 2, platform bottom shell 3, insulation layer 4, liquid nitrogen chamber 5, temperature-controlled heating plate 6, digital display temperature control module 7, and thermocouple temperature measuring device 8 according to Example 1 to form a temperature-controlled freezing platform.

[0078] 2. Preparation of dilute solution ink: Sodium alginate and deionized water are mixed at a mass ratio of 50:1. The mixture is stirred for 1 hour using a stirrer-deaerator, and then deaerated for 30 minutes.

[0079] 3. Adjust the temperature of the temperature-controlled freezing platform: When a certain amount of liquid nitrogen is introduced and the copper plate 1 reaches a certain low temperature, the temperature-controlled heating plate 6 is turned on and heated to a certain temperature. When the reading of the thermocouple temperature measuring device 8 is lower than the target temperature, the introduction of liquid nitrogen is stopped and the temperature of the temperature-controlled heating plate 6 is increased. When the reading of the thermocouple temperature measuring device 8 is higher than the target temperature, liquid nitrogen is introduced again and the temperature of the temperature-controlled heating plate 6 is decreased, and the temperature of the copper plate 1 on the temperature-controlled freezing platform is adjusted to -20℃.

[0080] 4. Perform in-situ directional cryogenic assisted ink direct writing 3D printing: Load the prepared dilute solution ink into the ink direct writing 3D printer, set the printer nozzle diameter to 15μm, printing pressure to 10psi, and nozzle speed to 20mm / s, and use in-situ cryogenic technology as an aid to design and print the dilute solution model pattern on the cooled copper plate 1.

[0081] 5. Freeze-dry the printed dilute solution model pattern for 12 hours at a temperature of -50℃.

[0082] 6. Obtain lightweight materials with porous microstructures, which can be used for the manufacture of lightweight structural devices and microporous devices.

[0083] Example 6

[0084] This embodiment provides a high-precision dilute ink direct-write 3D printing method based on a temperature-controlled freezing platform. Temperature control is performed using the temperature-controlled freezing platform from Embodiment 1 and the temperature adjustment method from Embodiment 2. The specific implementation steps are as follows:

[0085] 1. Construct a temperature-controlled freezing platform: Assemble the copper plate 1, platform top cover 2, platform bottom shell 3, insulation layer 4, liquid nitrogen chamber 5, temperature-controlled heating plate 6, digital display temperature control module 7, and thermocouple temperature measuring device 8 according to Example 1 to form a temperature-controlled freezing platform.

[0086] 2. Preparation of dilute solution ink: Sodium alginate and deionized water are mixed at a mass ratio of 50:1. The mixture is stirred for 1 hour using a stirrer-deaerator, and then deaerated for 30 minutes.

[0087] 3. Adjust the temperature of the temperature-controlled freezing platform: When a certain amount of liquid nitrogen is introduced and the copper plate 1 reaches a certain low temperature, the temperature-controlled heating plate 6 is turned on and heated to a certain temperature. When the reading of the thermocouple temperature measuring device 8 is lower than the target temperature, the introduction of liquid nitrogen is stopped and the temperature of the temperature-controlled heating plate 6 is increased. When the reading of the thermocouple temperature measuring device 8 is higher than the target temperature, liquid nitrogen is introduced again and the temperature of the temperature-controlled heating plate 6 is decreased, and the temperature of the copper plate 1 on the temperature-controlled freezing platform is adjusted to -40℃.

[0088] 4. Perform in-situ directional cryogenic assisted ink direct writing 3D printing: Load the prepared dilute solution ink into the ink direct writing 3D printer, set the printer nozzle diameter to 15μm, printing pressure to 10psi, and nozzle speed to 20mm / s, and use in-situ cryogenic technology as an aid to design and print the dilute solution model pattern on the cooled copper plate 1.

[0089] 5. Freeze-dry the printed dilute solution model pattern for 12 hours at a temperature of -50℃.

[0090] 6. Obtain lightweight materials with porous microstructures, which can be used for the manufacture of lightweight structural devices and microporous devices.

[0091] Example 7

[0092] This embodiment provides a high-precision dilute ink direct-write 3D printing method based on a temperature-controlled freezing platform. Temperature control is performed using the temperature-controlled freezing platform from Embodiment 1 and the temperature adjustment method from Embodiment 2. The specific implementation steps are as follows:

[0093] 1. Construct a temperature-controlled freezing platform: Assemble the copper plate 1, platform top cover 2, platform bottom shell 3, insulation layer 4, liquid nitrogen chamber 5, temperature-controlled heating plate 6, digital display temperature control module 7, and thermocouple temperature measuring device 8 according to Example 1 to form a temperature-controlled freezing platform.

[0094] 2. Preparation of dilute solution ink: Sodium alginate and deionized water are mixed at a mass ratio of 50:1. The mixture is stirred for 1 hour using a stirrer-deaerator, and then deaerated for 30 minutes.

[0095] 3. Adjust the temperature of the temperature-controlled freezing platform: When a certain amount of liquid nitrogen is introduced and the copper plate 1 reaches a certain low temperature, the temperature-controlled heating plate 6 is turned on and heated to a certain temperature. When the reading of the thermocouple temperature measuring device 8 is lower than the target temperature, the introduction of liquid nitrogen is stopped and the temperature of the temperature-controlled heating plate 6 is increased. When the reading of the thermocouple temperature measuring device 8 is higher than the target temperature, liquid nitrogen is introduced again and the temperature of the temperature-controlled heating plate 6 is decreased, and the temperature of the copper plate 1 on the temperature-controlled freezing platform is adjusted to -60℃.

[0096] 4. Perform in-situ directional cryogenic assisted ink direct writing 3D printing: Load the prepared dilute solution ink into the ink direct writing 3D printer, set the printer nozzle diameter to 15μm, printing pressure to 10psi, and nozzle speed to 20mm / s, and use in-situ cryogenic technology as an aid to design and print the dilute solution model pattern on the cooled copper plate 1.

[0097] 5. Freeze-dry the printed dilute solution model pattern for 12 hours at a temperature of -50℃.

[0098] 6. Obtain lightweight materials with porous microstructures, which can be used for the manufacture of lightweight structural devices and microporous devices.

[0099] Table 1. Parameters and printing effects of dilute solution in the examples.

[0100]

[0101]

[0102] Analysis of the experimental data in Table 1 shows that, under different temperature environments, the formation effect of the diluted solution model pattern in ink-direct writing 3D printing on copper plate 1 was poor when the temperature of copper plate 1 was at room temperature without a temperature-controlled freezing platform or at 0℃ using a temperature-controlled freezing platform. When the temperature of copper plate 1 was at -20℃ using a temperature-controlled freezing platform, the diluted solution model pattern could be basically formed, but the resolution was low. When the temperature of copper plate 1 was above -40℃ using a temperature-controlled freezing platform, the formation effect of the diluted solution model pattern in ink-direct writing 3D printing was good. This indicates that the method has a promoting effect on the formation effect of diluted solution model patterns in ink-direct writing 3D printing.

[0103] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A temperature-controlled freezing platform apparatus, characterized by, The temperature control freezing platform comprises a copper plate, a platform top cover, a platform bottom shell, a thermal insulation layer, a liquid nitrogen bin, a temperature control heating plate, a digital display temperature control module and a thermocouple temperature measuring device, wherein: The copper plate is placed in the round hole on the platform top cover, and the bottom surface of the copper plate is connected with the flange around the round hole on the bottom surface of the platform top cover; The platform top cover is installed with the platform bottom shell through the L-shaped latches at the four corners; The thermal insulation layer is filled in the platform bottom shell, and a recess is formed in the central area of the platform bottom shell for bearing the liquid nitrogen bin; The liquid nitrogen bin is placed in the recess in the central area of the thermal insulation layer; The temperature control heating plate is connected with the lower surface of the copper plate through the adhesive; The digital display temperature control module is connected with the temperature control heating plate through the electric wire; The temperature measuring lead of the thermocouple temperature measuring device is connected with the copper plate. The temperature control platform can be controlled between-100°C and 0°C. The temperature control freezing platform is printed according to the following steps: S1, assembling the temperature control freezing platform by assembling the copper plate, the platform top cover, the platform bottom shell, the thermal insulation layer, the liquid nitrogen bin, the temperature control heating plate, the digital display temperature control module and the thermocouple temperature measuring device; S2, preparing the dilute solution raw material by mixing the sodium alginate and the deionized water according to a certain mass ratio and stirring; S3, passing the liquid nitrogen into the temperature control freezing platform built in step S1, and turning on the temperature control heating plate to set the temperature of the copper plate on the temperature control freezing platform to a certain temperature; S4, loading the dilute solution prepared in step S2 into the needle tube of the ink direct writing 3D printer, and printing the pattern on the copper plate on the temperature control freezing platform with the temperature set in step S3; 2. The thermoregulated freezing platform apparatus of claim 1, wherein, The dilute solution used is a solution without shear thinning property, and the printed product pattern is a high-resolution pattern.

3. The thermoregulated freezing platform apparatus of claim 1, wherein, The copper plate has a diameter of 60 mm and a thickness of 2 mm, has good heat conduction performance, and is used to bear the pattern model printed by the ink direct writing 3D printer.

4. The thermoregulated freezing platform apparatus of claim 1, wherein, The temperature control heating plate can be precisely controlled between 0-100°C through the digital display control module.

5. The thermoregulated freezing platform apparatus of claim 1, wherein, The liquid nitrogen bin is a stainless steel bowl with a circular truncated cone shape, an opening end diameter of 60 mm, a bottom diameter of 40 mm, a height of 28 mm, and a wall thickness of 1 mm.

6. The thermoregulated freezing platform apparatus of claim 1, wherein, The thermal insulation layer is aluminum silicate insulation cotton, which is filled into the temperature control freezing platform to achieve the effect of continuous low-temperature freezing of the temperature control freezing platform. The platform bottom shell is made of PLA material through 3D printing, has a length of 120 mm, a width of 75 mm, a height of 38 mm, and a wall thickness of 1 mm, and has an opening on the side edge for the input of liquid nitrogen. The platform top cover is made of PLA material through 3D printing, has a length of 120 mm, a width of 75 mm, and a thickness of 2 mm, has a 60 mm diameter round hole on the top, and has a flange with a thickness of 1 mm around the round hole on the bottom to bear the copper plate.

7. The thermoregulated freezing platform apparatus of claim 1, wherein, The magnetic stirrer is used to stir the dilute solution ink slurry in S2 for 1-12 h to fully mix, or manual grinding is used for 20 min-2 h, or the stirring-deaeration machine is used to stir for 10 min-1 h and then deaerate for 10 min-1 h.

8. The thermoregulated freezing platform apparatus of claim 1, wherein, The temperature regulation of the copper plate in S3 includes the following steps: The temperature-controlled heating plate is attached to the bottom surface of the copper plate, when a certain amount of liquid nitrogen is introduced, the copper plate reaches a certain low temperature state, the temperature-controlled heating plate is turned on and heated to a certain temperature, when the thermocouple temperature measuring device shows a value lower than the target temperature, the introduction of liquid nitrogen is stopped and the temperature of the temperature-controlled heating plate is increased, when the thermocouple temperature measuring device shows a value higher than the target temperature, liquid nitrogen is introduced again and the temperature of the temperature-controlled heating plate is decreased, so that the temperature of the copper plate can be regulated between -100°C and -0°C.

9. The thermoregulated freezing platform apparatus of claim 1, wherein, The nozzle diameter of the ink direct writing 3D printer in S4 is 10-1000 μm, the printing pressure is 5-100 psi, the needle speed is 1-50 mm / s, the layer height is consistent with the nozzle diameter, and the shape and structure of the printing are modeled by 3D software and sliced to be imported into the printer system.

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