High-precision rapid manufacturing process of complex inner cavity structure flexible metamaterial and automatic production device thereof

Abstract

The existing silica gel forming process has problems of great forming difficulty, poor forming precision, low preparation efficiency, high mold cost and the like for preparing flexible metamaterials with complex inner cavities. The application discloses a high-precision rapid manufacturing process and an automatic production device for flexible metamaterials with complex inner cavity structures. A polyvinyl alcohol water-soluble mold is prepared by using a precise 3D printing technology, a detachable outer mold is matched, a position is constrained by using a limiting retainer matched with the water-soluble mold, and a layered pouring forming process is supplemented. Meanwhile, a preparation device suitable for industrial automatic production is provided, and automatic, efficient and precise preparation of the flexible metamaterials can be realized.

Description

Technical Field

[0001] This invention relates to the field of precision complex structure fabrication technology for flexible silicone, and in particular to a high-precision rapid manufacturing process and automated production device for flexible metamaterials with complex internal cavity structures. Background Technology

[0002] Metamaterials are a class of novel functional structured materials that acquire electromagnetic, acoustic, mechanical, or thermal properties through specially designed unit structures. Their core properties do not entirely depend on the material's chemical composition, but rather on the periodic structural design and overall configuration control on a macroscopic scale. Compared to traditional materials, metamaterials have the significant advantage of achieving properties that are difficult or even impossible for natural materials to possess, such as negative refraction, beam-directed control, super-strong wave absorption, vibration reduction and noise reduction, lightweight and high strength, energy absorption, and multifunctional integration. Therefore, they have broad application prospects in aerospace, defense equipment, communication technology, construction engineering, medical devices, and intelligent manufacturing.

[0003] Currently, the fabrication of metamaterials with complex internal cavity structures faces the following challenges: On the one hand, most existing complex internal cavity metamaterials are made of metals, hard resins, or other rigid materials (such as patent CN121862063A). While this ensures high structural stability and performance consistency, its inherent rigidity limits its application on complex curved surfaces, confined spaces, and deformable component surfaces. On the other hand, existing flexible silicone precision injection molding processes can only fabricate solid structures or hollow structures with openings larger than the internal cavity. The unique characteristics of complex internal cavity metamaterials—with small openings and large internal cavities—lead to significant fabrication difficulties, complex processes, and an inability to flexibly adjust the structural configuration (such as patent CN116766497A).

[0004] Against this backdrop, efficient fabrication methods for complex internal cavity metamaterials that are suitable for complex curved surface conditions and have flexible adaptability have become a research hotspot, with significant theoretical and practical engineering value. Summary of the Invention

[0005] This invention innovatively proposes a high-precision, rapid manufacturing process and automated production device for flexible metamaterials with complex internal cavity structures. It utilizes a 3D-printed polyvinyl alcohol water-soluble inner mold, combined with a 3D-printed outer mold and fixing frame, and employs a multiple-casting technique with silicone. The necked cavity can be integrally formed without secondary bonding, achieving low-cost, high-precision, and rapid fabrication of flexible metamaterial structures with complex internal cavity structures. The high-precision, rapid manufacturing process and automated production device for flexible metamaterials with complex internal cavity structures provided by this invention can be used for the fabrication of flexible metamaterials and can be extended to the automated manufacturing of other flexible precision structures.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a high-precision and rapid manufacturing process for flexible metamaterials with complex internal cavity structures. The process includes the following steps:

[0008] 1) Preparation of liquid silicone raw materials. Specifically, silicone is weighed using a precision balance according to the ratio, and the A and B two-component silicone is mixed. The two-component silicone is thoroughly mixed using an electric stirrer to obtain a mixed silicone liquid to be cured.

[0009] 2) Prepare silica liquid containing filler. Specifically, accurately weigh the filler powder using a precision balance according to the mass of the filler to be added, add it to the silica liquid prepared in step 1), and discretize the filler components using an electric stirrer and an ultrasonic disruptor.

[0010] 3) Defoaming the silica gel liquid. Specifically, place the mixed silica gel liquid from step 2) into a vacuum centrifuge to eliminate air bubbles.

[0011] 4) Fabrication of a peelable outer mold and a water-soluble inner mold, as well as a fixing frame (including a bottom fixing frame and a top fixing frame for the inner mold). Specifically, an outer mold with a split-part mold design is fabricated using a rigid material via a 3D printer, and a water-soluble inner mold is fabricated using a polyvinyl alcohol material with a complex internal cavity shape via a 3D printer. A bottom fixing frame and a top fixing frame for the inner mold are also fabricated using a 3D printer to fix and limit the water-soluble mold.

[0012] 5) Close the detachable outer mold. Specifically, align the outer mold prepared in step 4) with the positioning pins on the mold and close the split outer mold, and seal the joint with acetate-based acrylic adhesive tape.

[0013] 6) Arrange and fix the water-soluble inner mold. Specifically, the end effector of the robotic arm is used to arrange the polyvinyl alcohol water-soluble inner mold prepared in step 4) according to the designed multiple complex inner cavity structure and place it in the bottom fixing frame and top fixing frame of the inner mold prepared in step 4) that match the complex inner cavity. After the water-soluble inner mold is tightly combined with the top fixing frame of the inner mold, the bottom fixing frame of the inner mold is removed.

[0014] 7) Assemble the outer mold and the water-soluble inner mold. Specifically, the end effector of the robotic arm is used to assemble and close the water-soluble inner mold assembled in step 6) with its fixed frame and the outer mold.

[0015] 8) Layered pouring and curing of silicone. Specifically, the silicone liquid after degassing in step 3) is poured into the inner and outer molds assembled in step 7) through the reserved pouring channel using the end effector of the robotic arm. Multiple pouring and curing processes are required during the pouring process.

[0016] 9) Remove the outer mold. Specifically, the outer mold of the metamaterial, which has been cured in step 8), is peeled off using the end effector of the robotic arm.

[0017] 10) Water-soluble removal of the inner mold. Specifically, using the end effector of a robotic arm, the metamaterial, which has undergone outer mold peeling in step 9) but is still attached to the water-soluble inner mold, is placed in the aforementioned automated extrusion demolding device with circulating water to perform water-soluble demolding of the inner mold. Heating and circulating water are used during the water-soluble demolding process. After sufficient hydrolysis, a flexible complex inner cavity metamaterial filled with water is obtained.

[0018] 11) Drying. Specifically, the flexible silicone complex cavity metamaterial, which has been fully dehydrated and demolded in step 10), is transferred to an automatic drying device for drying to obtain the prepared flexible complex cavity metamaterial.

[0019] Preferably, the flexible silicone material in step 1) is an AB two-component platinum silicone with a mixing ratio of 1:0.5 to 1:2 by mass.

[0020] Preferably, the flexible silicone material in step 2) may contain no filler or may contain one or any combination of fillers selected from silica, calcium carbonate, and talc, with the mass ratio of the filler being 0% to 40%.

[0021] Preferably, the complex internal cavity flexible metamaterial in step 4) consists of two parts: an inner cavity and a neck opening; the volume and cross-sectional area of ​​the inner cavity are both larger than the volume and cross-sectional area of ​​the neck opening; the inner cavity and neck opening in the complex internal cavity are air-formed cavities, surrounded by silicone to form the cavity shape; the flexible metamaterial consists of multiple complex internal cavities, each with a different size, and the cavities are arranged regularly with the spacing between adjacent cavities equal to the wall spacing between them.

[0022] Preferably, in step 4), the outer contour of the polyvinyl alcohol water-soluble inner mold is a cavity structure with a strictly designed complex inner cavity, and the internal structure filling density is 15%.

[0023] Preferably, the internal filling structure of the polyvinyl alcohol water-soluble inner mold in step 4) can be any filling structure with a supporting function, such as triangle, straight line, grid, regular tetrahedron and spiral.

[0024] Preferably, the shape of the complex cavity in step 4) is not limited to a cuboid cavity and a cylindrical neck opening, but can be any shape that satisfies the requirements of having a neck opening and a cavity structure; the cavity wall thickness is 1~5mm; the cavity volume is 0.5~20 cubic millimeters; the neck opening diameter is 1~6mm; the overall envelope appearance of the complex cavity metamaterial unit can be any three-dimensional shape of the outer contour surface of the cavity, such as a cuboid or a sphere.

[0025] Preferably, the positioning pin of the rigid split-part mold outer mold in step 5) is a positioning pin and a positioning pin hole with a square cross-section adjacent to the mold closing surface. The shape of the positioning pin and the pin hole is not limited to a rectangle, a circle, a triangle, or other shapes.

[0026] Preferably, the tape used in step 5) is not limited to any type of acrylic adhesive tape with an arbitrary substrate;

[0027] Preferably, in step 8), the silicone is poured in layers 2 to 5 times;

[0028] Preferably, in step 8), the thickness of each layer of silicone pouring is 1mm to 10mm.

[0029] Preferably, the water change cycle for demolding in step 10) is once every 1 to 24 hours;

[0030] Preferably, the water demolding heating temperature in step 10) is 40~90 degrees Celsius.

[0031] The present invention also provides a high-precision, rapid, automated manufacturing apparatus for flexible metamaterials with complex internal cavity structures, characterized in that it includes a robotic arm with a precision clamping mold and a silicone casting end effector, an automated extrusion and demolding device for water-soluble mold and water circulation, and an automatic drying device.

[0032] The water-soluble mold-forming water circulation automated extrusion demolding device and the automatic drying device are both arranged within the reach of the end effector of the robotic arm;

[0033] The end effector is mounted at the end of the robotic arm;

[0034] The end effector of the robotic arm is used for precision gripping of a detachable outer mold, a water-soluble inner mold, and a silicone container;

[0035] The robotic arm end effector can also be used to transfer flexible metamaterials to be demolded and dried to automated demolding and drying devices.

[0036] The water-soluble molded automatic extrusion and demolding device consists of a liquid electric heating device, an automatic extrusion device, and a water circulation device.

[0037] The water circulation device consists of an inlet pipe, an outlet pipe, and a pumping device.

[0038] The automatic extrusion device consists of an extrusion contact surface and an extrusion power source;

[0039] Preferably, the electric heating device can be any container capable of heating water or other liquids, including electric heating pots, gas heating pots, and steam heating pots, etc.

[0040] Preferably, the contact surface of the automatic extrusion device can be a flat extrusion device or any device that can apply surface pressure to the metamaterial to be demolded;

[0041] Preferably, the power source of the automatic extrusion device can be any mechanism capable of linear or extrusion motion, such as a motor screw, hydraulic actuator, or pneumatic cylinder.

[0042] Preferably, the inlet pipe and outlet pipe can be any type of pipe for transporting liquid, such as rubber pipe, plastic pipe, or nylon pipe;

[0043] Preferably, the pumping device can be any type of pump capable of conveying liquid, such as an electric pump, a pneumatic diaphragm pump, a pneumatic piston pump, or a hydraulic motor pump.

[0044] Preferably, the automatic drying device is a vacuum drying oven, a forced-air drying oven, or an oven, and can be any kind of equipment capable of drying objects.

[0045] This invention provides a high-precision rapid manufacturing process and automated production device for flexible metamaterials with complex internal cavity structures. Compared with existing technologies, the advantages are as follows:

[0046] 1. The proposed method for preparing flexible metamaterials with complex internal cavity structures enables traditional rigid metamaterials to have flexible and deformable capabilities, making them well applicable to complex curved surfaces, narrow spaces, and deformable component surfaces.

[0047] 2. The fabrication scheme of the flexible metamaterial with complex internal cavity structure proposed in this invention can realize the integrated fabrication of complex necked cavity structures, and significantly improve the forming accuracy of the necked cavity.

[0048] 3. The automated fabrication device for complex internal cavity flexible metamaterials proposed in this invention realizes the automated fabrication of complex internal cavity flexible metamaterials, significantly improves the efficiency of fabrication of complex internal cavity flexible metamaterial structures, and reduces the fabrication cost. Attached Figure Description

[0049] Figure 1 This is an overall device layout diagram of an automated production device for flexible metamaterials with complex internal cavity structures according to the present invention.

[0050] Figure 2 This is a cross-sectional schematic diagram of the complex internal cavity structure of the flexible metamaterial of the present invention.

[0051] Figure 3 This is a schematic diagram of the assembly of a water-soluble internal mold for the precision forming process of flexible metamaterials with complex internal cavity structures according to the present invention.

[0052] Figure 4 This is a schematic diagram of the assembly of inner and outer molds for the precision forming process of flexible metamaterials with complex internal cavity structures according to the present invention.

[0053] Figure 5 This is a schematic diagram of the layered casting process for the precision forming of the complex internal cavity structure of the flexible metamaterial of the present invention.

[0054] Figure 6 This is a schematic diagram of the automatic extrusion and demolding device of the automated production equipment for precision molding of flexible metamaterials with complex internal cavity structures according to the present invention.

[0055] Figure 7 This is a flowchart illustrating the high-precision rapid manufacturing process of a flexible metamaterial with a complex internal cavity structure according to the present invention.

[0056] The markings in the diagram are as follows: 1—robotic arm; 2—3D printer; 3—assembled inner and outer molds; 4—automatic extrusion and demolding device with circulating water; 5—automatic drying device; 6—flexible metamaterial with complex internal cavity structure; 601—neck of the inner cavity of the flexible metamaterial with complex internal cavity structure; 602—inner cavity of the flexible metamaterial with complex internal cavity structure; 7—bottom fixing frame of the inner mold; 8—water-soluble inner mold; 9—top fixing frame of the inner mold; 901—silicone casting channel; 10—outer mold; 1001—casting scale line of the outer mold; 1002—positioning pin of the outer mold; 11—fixed gantry frame; 12—motor; 13—coupling; 14—lead screw; 15—moving extrusion plate; 16—electric heating pot; 17—water inlet pipe; 18—water outlet pipe. Detailed Implementation

[0057] The method of the present invention will now be described in detail with reference to the accompanying drawings, and the drawings do not constitute a limitation on the embodiments of the present invention. In the description of the specific embodiments, for the sake of simplicity, "metamaterial" and "flexible metamaterial" should both be understood as "flexible metamaterial with complex internal cavity structure", "internal cavity" should be understood as "internal cavity of flexible metamaterial with complex internal cavity structure", "internal mold" should be understood as "polyvinyl alcohol water-soluble internal mold", "first casting" corresponds to "the first layer of casting" and "second casting" corresponds to "the second layer of casting", and so on. In the description of this application, the terms "upper", "lower", "outer", "inner", "top" and "bottom", etc., indicate the position or direction used to describe the relative relationship of the various components in the drawings. "First casting" and "second casting" indicate the number of casting processes and the number of layers. The above indicative characters and sequential expressions are only for the convenience of understanding this application and simplifying the description, and do not indicate the necessary position and necessary process parameters of the components, and therefore should not be construed as a limitation on the scope of protection of this application.

[0058] This invention provides a high-precision, rapid manufacturing process for flexible metamaterials with complex internal cavity structures, combined with... Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 7 To provide a detailed explanation, among which Figure 7 This is a process flow diagram. The process includes the following steps:

[0059] 1) Preparation of liquid silicone raw materials. Weigh the silicone according to the ratio using a precision balance, mix the AB two-component silicone, and use an electric stirrer to fully mix the two-component silicone to obtain the mixed silicone liquid to be cured.

[0060] 2) Prepare silica liquid containing filler. Accurately weigh the filler powder using a precision balance according to the mass of the filler to be added, and add it to the silica liquid prepared in step 1). Discretize the filler components using an electric stirrer and an ultrasonic disruptor.

[0061] 3) Defoaming the silica gel liquid. Place the mixed silica gel liquid from step 2) into a vacuum centrifuge to remove air bubbles.

[0062] 4) Fabricate a peelable outer mold 10 and a water-soluble inner mold 8, as well as a fixing frame (including a bottom fixing frame 7 and a top fixing frame 9 for the inner mold). Specifically, the outer mold 10 with a split-and-join design is fabricated using a rigid material with a 3D printer, and the water-soluble inner mold 8 is fabricated using a polyvinyl alcohol material with a complex internal cavity shape with a 3D printer. The bottom fixing frame 7 and the top fixing frame 9 for fixing and limiting the water-soluble mold are fabricated using a 3D printer.

[0063] 5) Close the detachable outer mold 10. Align the prepared outer mold 10 from step 4) with the positioning pins 1002 on the mold and close the split outer mold 10, as shown. Figure 4 As shown, the seams are sealed and bonded using acetate-based acrylic adhesive tape.

[0064] 6) Arrange and fix the water-soluble inner mold 8. Using the end effector of the robotic arm 1, arrange the polyvinyl alcohol water-soluble inner mold 8 prepared in step 4) according to the designed multiple complex inner cavity structure and place it within the bottom fixing frame 7 and top fixing frame 9 of the inner mold prepared in step 4) that match the complex inner cavity, as shown. Figure 3 As shown. After the water-soluble inner mold 8 is tightly connected with the top fixing frame 9 of the inner mold, the bottom fixing frame 7 of the inner mold is removed.

[0065] 7) Assemble the outer mold 10 and the water-soluble inner mold 8. Using the end effector of the robotic arm 1, assemble the water-soluble inner mold assembled in step 6) with its fixing frame and the outer mold, as shown below. Figure 4 As shown.

[0066] 8) Layered pouring and curing of silicone. Using the end effector of robotic arm 1, the degassed silicone liquid from step 3) is poured through the pre-reserved pouring channel 901 into the inner and outer molds 10 assembled in step 7). The pouring process requires 2-5 pouring and curing cycles. Figure 5 As shown, the top liquid level of the last silicone pour is... Figure 4 The outer mold 10 is flush with the casting scale line 1001.

[0067] 9) Remove the outer mold 10. Use the end effector of the robotic arm 1 to peel off the outer mold 10 of the flexible silicone metamaterial that has been cured in step 8).

[0068] 10) Water-soluble removal of the inner mold 8. Using the end effector of the robotic arm 1, the metamaterial, which has been peeled off from the outer mold 10 in step 9) but is still attached to the water-soluble inner mold 8, is placed in the aforementioned automated extrusion demolding device 4 with circulating water to perform water-soluble demolding of the inner mold 8. Heating and circulating water are used to assist in the water-soluble demolding process. After sufficient hydrolysis, a flexible complex inner cavity metamaterial 6 filled with water is obtained.

[0069] 11) Drying. The flexible silicone complex cavity metamaterial 6, which has been fully dehydrated and demolded in step 10), is transferred to the automatic drying device 5 for drying using the end effector of the robotic arm 1 to obtain the prepared flexible complex cavity metamaterial 6.

[0070] The flexible silicone material in step 1) is a two-component platinum silicone, and the preferred mixing ratio is 1:0.5 to 1:2 by mass, more preferably 1:0.9 to 1:1.1. The mixing ratio of the platinum silicone AB components is limited within the above range, which enables the silicone to have the fastest curing speed and the best curing effect.

[0071] In step 2), the filler added to the silicone is a particle or powder that enhances the mechanical properties (such as modulus, strength, etc.) of silicone, including: one or any combination of silica, calcium carbonate, talc (not limited to the above materials) that meets the requirements; in this invention, the silicone filler enhances the mechanical properties of silicone, effectively improving the modulus and toughness of the molded metamaterial; in this invention, the mass ratio of filler added to the silicone is preferably 0%~40%;

[0072] The complex internal cavity flexible metamaterial in step 4) consists of two parts: an inner cavity and a neck opening. The volume and cross-sectional area of ​​the inner cavity are both larger than those of the neck opening. Both the inner cavity and the neck opening are air-formed cavities, surrounded by a silicone envelope to form the cavity shape. The flexible metamaterial is composed of multiple complex cavities, each with a different size. The cavities are regularly arranged, with the spacing between them equal to the walls between adjacent cavities. Figure 2 As shown;

[0073] In step 4), the outer contour of the polyvinyl alcohol water-soluble inner mold 8 is a strictly designed complex internal cavity structure, and the internal structure filling density is preferably 5~30%, more preferably 10~15%. The internal filling density of the water-soluble inner mold 8 is limited to the above range, which can reduce the amount of polyvinyl alcohol while ensuring a certain structural strength, thereby increasing the water-dissolving speed of the water-soluble inner mold 8.

[0074] In step 4), the internal filling structure of the polyvinyl alcohol water-soluble inner mold is preferably one of any supporting filling structures such as triangles, straight lines, grids, regular tetrahedrons, and spirals, and more preferably grid filling.

[0075] In step 5), the locating pin of the hard split-part mold outer mold is preferably a locating pin with a square cross-section and a locating pin hole adjacent to the mold closing surface.

[0076] The preferred adhesive tape used in step 5) is an acrylic adhesive tape; the type of tape is limited to acrylic adhesives that can prevent silicone from reacting with unnecessary adhesives, thus affecting the silicone curing effect.

[0077] In step 8), the number of times the silicone is poured in layers is preferably 2 to 5 times, more preferably 3 to 4 times; the thickness of each pour in the silicone layer in step 8) is preferably 1 mm to 20 mm, more preferably 5 to 10 mm; the number of times the silicone is poured in layers is limited to the above range, which can ensure that the volume of silicone poured in each layer is small, thereby ensuring that the low-density filled water-soluble inner mold 8 will not move due to the buoyancy generated by the silicone liquid, affecting the molding accuracy. At the same time, it can also ensure that the air bubbles generated during pouring can be better discharged from the liquid surface, reducing pouring defects.

[0078] The preferred water replacement cycle for demolding in step 10) is once every 1 to 24 hours, more preferably once every 6 to 12 hours. The water replacement time is limited to the above range, which can ensure that the content of hydrolyzed polyvinyl alcohol in the water is at a low level while saving water resources, so that the interference will not affect the dissolution rate of the undissolved polyvinyl alcohol inner mold 8.

[0079] The preferred heating temperature for water-soluble mold release in step 10) is 40-90 degrees Celsius, more preferably 70-80 degrees Celsius. Limiting the heating temperature within the above range can improve the dissolution rate of the polyvinyl alcohol water-soluble mold 8.

[0080] In this invention, the shape of the complex internal cavity is preferably any shape that satisfies the requirements of a neck opening and a cavity structure, more preferably a rectangular internal cavity and a cylindrical neck opening, such as... Figure 2 The neck 601 and the cavity 602 of the flexible metamaterial with complex internal cavity structure are shown in the diagram. The shape of the cavity is limited to a cuboid cavity and a cylindrical neck opening, which can make the multiple complex internal cavities more regular and the wall thickness more uniform when they are closely arranged, thus making the metamaterial performance optimal.

[0081] In this invention, the wall thickness of the complex inner cavity is preferably 1-5 mm, more preferably 2-3 mm; the cavity volume of the complex inner cavity is preferably 0.5-20 cubic millimeters; the opening diameter of the neck 601 of the complex inner cavity is preferably 1-6 mm; the structural features of the complex inner cavity are limited within the above range, which can ensure the success rate of silicone casting, molding accuracy and metamaterial properties.

[0082] In this invention, the overall envelope appearance of the metamaterial unit is preferably one of the three-dimensional shapes of the outer contour surface of the resonant cavity, such as a cuboid or a sphere, and more preferably a cuboid, such as... Figure 1 As shown in Figure 6, the overall envelope of the metamaterial unit is defined as a cuboid, which makes the overall shape of the metamaterial more regular and facilitates the large-area arrangement of the metamaterial.

[0083] This invention also provides a high-precision, rapid, and automated fabrication device for flexible metamaterials with complex internal cavity structures, such as... Figure 1 and Figure 6 As shown. Its features include, sequentially arranged, a robotic arm 1 with a precision clamping mold and a silicone casting device, an automated extrusion and demolding device 4 for water-soluble mold and water circulation, and an automatic drying device 5, all required in the preparation process.

[0084] The Figure 1 The water-soluble mold-forming water circulation automated extrusion demolding device 4 and the automatic drying device 5 are both arranged within the reach of the end effector of the robotic arm; the end effector is installed at the end of the robotic arm 1; the end effector of the robotic arm 1 is used to precisely grip the detachable outer mold 10, the water-soluble inner mold 8 and the silicone container; the end effector of the robotic arm 1 can also be used to transfer the flexible metamaterial 6 to be demolded and dried to the automated demolding device 4 and the automatic drying device 5;

[0085] The Figure 6 The water-soluble mold-forming automatic extrusion and demolding device 4 consists of a liquid electric heating pot 16, an automatic extrusion device (including a fixed gantry frame 11, a motor 12, a coupling 13, a lead screw 14, and a moving extrusion disc 15), and a water circulation device; the water circulation device consists of an inlet pipe 17, an outlet pipe 18, and a water pump; the automatic extrusion device consists of a moving extrusion disc 15 at the extrusion contact surface and an extrusion power source;

[0086] Furthermore, the aforementioned Figure 6 The electric heating device can be any container that can heat water or other liquids, preferably an electric heating pot, a gas heating pot, or a steam heating pot, and more preferably an electric heating pot 16, which can use electricity to heat water; the electric heating device can accelerate the hydrolytic demolding of the polyvinyl alcohol water-soluble mold 8 contained in the flexible metamaterial 6.

[0087] Furthermore, the aforementioned Figure 6 The moving extrusion disc 15 of the automatic extrusion device 4 is preferably a flat extrusion device; the power source of the automatic extrusion device is preferably any mechanism capable of linear or extrusion motion, such as a motor screw, hydraulic actuator, or pneumatic cylinder, and more preferably a motor 12 screw 14 mechanism (including coupling 13); the motor 12 is mounted on the fixed gantry frame 11 and drives the screw 14 to rotate through the coupling 13. The forward and reverse rotation of the motor 12 and the screw 14 drives the moving extrusion disc 15 to move up and down, thereby applying extrusion force to the flexible metamaterial 6; the automatic extrusion device 4 with active water circulation can continuously apply extrusion force to the flexible metamaterial 6 that is being hydrolyzed and demolded, helping the hydrolyzed polyvinyl alcohol to be discharged from the neck 601 of the complex internal cavity structure of the flexible metamaterial;

[0088] Furthermore, the aforementioned Figure 6The inlet pipe 17 and outlet pipe 18 of the water circulation device of the automatic squeezing device 4 are preferably any kind of pipeline for conveying liquid, such as rubber pipe, plastic pipe, nylon pipe, etc., and more preferably PVC water pipe with internal fiber or steel wire reinforcement; the pumping device is preferably any kind of pump that can convey liquid, such as electric pump, pneumatic diaphragm pump, pneumatic piston pump and hydraulic motor pump.

[0089] Furthermore, the aforementioned Figure 1 The automatic drying device 5 is preferably a vacuum drying oven, a blower drying oven, or an oven, and more preferably a vacuum drying oven. The vacuum drying oven can reduce the boiling point of the liquid, allowing the liquid to be converted into a gaseous state more quickly and discharged through the neck 601 of the flexible metamaterial cavity of the complex internal structure.

[0090] Example 1

[0091] The high-precision rapid manufacturing process for the complex internal cavity structure flexible metamaterial in this embodiment includes the following steps:

[0092] 1) Preparation of liquid silicone raw materials. Weigh the silicone according to the ratio using a precision balance, mix the AB two-component silicone at a mass ratio of 1:1, and use an electric stirrer to fully mix the two-component silicone to obtain the mixed silicone liquid to be cured.

[0093] 2) Prepare silica liquid containing filler. Accurately weigh 20% by mass of silica filler powder using a precision balance according to the mass of the filler to be added, and add it to the silica liquid prepared in step 1). Discretize the filler components using an electric stirrer and an ultrasonic disruptor.

[0094] 3) Defoaming the silica gel liquid. Place the mixed silica gel liquid from step 2) into a vacuum centrifuge to remove air bubbles.

[0095] 4) Fabrication of a peelable outer mold 10, a water-soluble inner mold 8, and a fixing frame (including a bottom fixing frame 7 and a top fixing frame 9 for the inner mold). Specifically, an outer mold 10 with a split-part mold design is fabricated using a rigid material via a 3D printer, and a water-soluble inner mold 8 is fabricated using a polyvinyl alcohol material with a complex internal cavity shape via a 3D printer. The inner mold has a grid-like infill pattern with an infill density of 15%. The bottom fixing frame 7 and the top fixing frame 9 for fixing and limiting the water-soluble mold are fabricated using a 3D printer.

[0096] 5) Close the peelable outer mold 10. Align the prepared outer mold 10 from step 4) with the locating pins 1002 on the mold and close the split outer mold 10. The locating pins are square-section locating pins and locating pin holes, as shown in the image. Figure 4 As shown, the seams are sealed and bonded using acetate-based acrylic adhesive tape.

[0097] 6) Arrange and fix the water-soluble inner mold 8. Using the end effector of the robotic arm 1, arrange the polyvinyl alcohol water-soluble inner mold 8 prepared in step 4) according to the designed multiple complex inner cavity structure and place it within the bottom fixing frame 7 and top fixing frame 9 of the inner mold prepared in step 4) that match the complex inner cavity, as shown. Figure 3 As shown. After the water-soluble inner mold 8 is tightly connected with the top fixing frame 9 of the inner mold, the bottom fixing frame 7 of the inner mold is removed.

[0098] 7) Assemble the outer mold 10 and the water-soluble inner mold 8. Using the end effector of the robotic arm 1, assemble the water-soluble inner mold assembled in step 6) with its fixing frame and the outer mold, as shown below. Figure 4 As shown.

[0099] 8) Layered pouring and curing of silicone. Using the end effector of robotic arm 1, the degassed silicone liquid from step 3) is poured through the pre-reserved pouring channel 901 into the inner and outer molds 10 assembled in step 7). Pouring and curing are performed in three stages, each with a thickness of 10mm. Figure 5 As shown, the top liquid level of the last silicone pour is... Figure 4 The outer mold 10 is flush with the casting scale line 1001.

[0100] 9) Remove the outer mold 10. Use the end effector of the robotic arm 1 to peel off the outer mold 10 of the flexible silicone metamaterial that has been cured in step 8).

[0101] 10) Water-soluble removal of the inner mold 8. Using the end effector of the robotic arm 1, the metamaterial, which has been peeled off from the outer mold 10 in step 9) but is still attached to the water-soluble inner mold 8, is placed in the aforementioned automated extrusion demolding device 4 with circulating water to perform water-soluble demolding of the inner mold 8. During water-soluble demolding, heating and circulating water are used as supplementary methods. The heating temperature is 80 degrees Celsius, and the water is changed once every 12 hours. After sufficient hydrolysis, a flexible complex inner cavity metamaterial 6 filled with water is obtained.

[0102] 11) Drying. The flexible silicone complex cavity metamaterial 6, which has been fully dehydrated and demolded in step 10), is transferred to the automatic drying device 5 for drying using the end effector of the robotic arm 1 to obtain the prepared flexible complex cavity metamaterial 6.

[0103] The aforementioned flexible metamaterial with a complex internal cavity structure consists of two parts: an internal cavity and a neck opening, such as... Figure 2 As shown; the volume and cross-sectional area of ​​the complex internal cavity structure made of flexible metamaterial are both larger than the volume and cross-sectional area of ​​the neck opening, such as... Figure 2As shown; the inner cavity and neck opening of the complex internal cavity structure flexible metamaterial are air-formed cavities, surrounded by a silicone envelope of a certain thickness to form the cavity shape, such as... Figure 2 As shown; the complex internal cavity structure flexible metamaterial consists of multiple internal cavities, each with a different size. These cavities are arranged regularly, with the spacing between them equal to the wall spacing between adjacent cavities, such as... Figure 2 As shown.

[0104] The complex internal cavity structure of the flexible metamaterial has a cuboid cavity shape and a cylindrical neck opening, such as... Figure 2 The neck 601 and cavity 602 of the flexible metamaterial with a complex internal cavity structure are shown. The wall thickness of the inner cavity of the flexible metamaterial with a complex internal cavity structure is 2 mm; the volume of the inner cavity of the flexible metamaterial with a complex internal cavity structure varies from 0.5 to 20 cubic millimeters; the opening diameter of the neck 601 of the flexible metamaterial with a complex internal cavity structure varies from 1 to 6 mm. The overall envelope of the metamaterial unit has a cuboid shape, as shown in the figure. Figure 1 The flexible metamaterial with a complex internal cavity structure is shown in Figure 6.

[0105] An automated fabrication apparatus for precision molding of flexible metamaterials with complex internal cavity structures, as described in this embodiment, is used. Figure 1 and Figure 6 As shown. Its features include, sequentially arranged, a robotic arm 1 with a precision clamping mold and a silicone casting device, an automated extrusion and demolding device 4 for water-soluble mold and water circulation, and an automatic drying device 5, all required in the preparation process.

[0106] The Figure 1 The water-soluble mold-forming water circulation automated extrusion demolding device 4 and the automatic drying device 5 are both arranged within the reach of the end effector of the robotic arm; the end effector is installed at the end of the robotic arm 1; the end effector of the robotic arm 1 is used to precisely grip the detachable outer mold 10, the water-soluble inner mold 8 and the silicone container; the end effector of the robotic arm 1 can also be used to transfer the flexible metamaterial 6 to be demolded and dried to the automated demolding device 4 and the automatic drying device 5;

[0107] The Figure 6 The water-soluble mold-forming automatic extrusion and demolding device 4 consists of a liquid electric heating pot 16, an automatic extrusion device (including a fixed gantry frame 11, a motor 12, a coupling 13, a lead screw 14, and a moving extrusion disc 15), and a water circulation device; the water circulation device consists of an inlet pipe 17, an outlet pipe 18, and a water pump; the automatic extrusion device consists of a moving extrusion disc 15 at the extrusion contact surface and an extrusion power source;

[0108] The Figure 6 The electric heating device in the middle is an electric heating pot 16; the Figure 6 The automatic extrusion device 4 is equipped with a moving extrusion disc 15, which is a flat extrusion device. The power source of the automatic extrusion device is a motor 12 and a lead screw 14 mechanism (including a coupling 13). The motor 12 is mounted on a fixed gantry frame 11 and drives the lead screw 14 to rotate through the coupling 13. The forward and reverse rotation of the motor 12 and the lead screw 14 drives the moving extrusion disc 15 to move up and down, thereby applying extrusion force to the flexible metamaterial 6. The automatic extrusion device 4 with active water circulation can continuously apply extrusion force to the flexible metamaterial 6 with a complex internal cavity structure that is being hydrolyzed and demolded, helping the hydrolyzed polyvinyl alcohol to be discharged from the neck 601 of the complex internal cavity.

[0109] The Figure 6 The water inlet pipe 17 and water outlet pipe 18 of the water circulation device of the automatic extrusion device 4 are PVC water pipes with internal fiber reinforcement; the water pumping device is an electric pump.

[0110] The Figure 1 The automatic drying device 5 in the middle is a vacuum drying oven.

[0111] Example 2

[0112] The high-precision rapid manufacturing process for the complex internal cavity structure flexible metamaterial in this embodiment includes the following steps:

[0113] 1) Preparation of liquid silicone raw materials. Weigh the silicone according to the ratio using a precision balance, mix the AB two-component silicone at a mass ratio of 1:1, and use an electric stirrer to fully mix the two-component silicone to obtain the mixed silicone liquid to be cured.

[0114] 2) Prepare silica liquid containing filler. Accurately weigh 30% by mass of silica filler powder using a precision balance according to the mass of the filler to be added, and add it to the silica liquid prepared in step 1). Discretize the filler components using an electric stirrer and an ultrasonic disruptor.

[0115] 3) Defoaming the silica gel liquid. Place the mixed silica gel liquid from step 2) into a vacuum centrifuge to remove air bubbles.

[0116] 4) Fabrication of a peelable outer mold 10, a water-soluble inner mold 8, and a fixing frame (including a bottom fixing frame 7 and a top fixing frame 9 for the inner mold). Specifically, an outer mold 10 with a split-part mold design is fabricated using a rigid material via a 3D printer, and a water-soluble inner mold 8 is fabricated using a polyvinyl alcohol material with a complex internal cavity shape via a 3D printer. The inner mold has a grid-like infill pattern with an infill density of 10%. The bottom fixing frame 7 and the top fixing frame 9 for fixing and limiting the water-soluble mold are fabricated using a 3D printer.

[0117] 5) Close the peelable outer mold 10. Align the prepared outer mold 10 from step 4) with the locating pins 1002 on the mold and close the split outer mold 10. The locating pins are square-section locating pins and locating pin holes, as shown in the image. Figure 4 As shown, the seams are sealed and bonded using acetate-based acrylic adhesive tape.

[0118] 6) Arrange and fix the water-soluble inner mold 8. Using the end effector of the robotic arm 1, arrange the polyvinyl alcohol water-soluble inner mold 8 prepared in step 4) according to the designed multiple complex inner cavity structure and place it within the bottom fixing frame 7 and top fixing frame 9 of the inner mold prepared in step 4) that match the complex inner cavity, as shown. Figure 3 As shown. After the water-soluble inner mold 8 is tightly connected with the top fixing frame 9 of the inner mold, the bottom fixing frame 7 of the inner mold is removed.

[0119] 7) Assemble the outer mold 10 and the water-soluble inner mold 8. Using the end effector of the robotic arm 1, assemble the water-soluble inner mold assembled in step 6) with its fixing frame and the outer mold, as shown below. Figure 4 As shown.

[0120] 8) Layered pouring and curing of silicone. Using the end effector of robotic arm 1, the degassed silicone liquid from step 3) is poured through the pre-reserved pouring channel 901 into the inner and outer molds 10 assembled in step 7). Pouring and curing are performed in four stages, with each pour being 7.5 mm thick. Figure 5 As shown, the top liquid level of the last silicone pour is... Figure 4 The outer mold 10 is flush with the casting scale line 1001.

[0121] 9) Remove the outer mold 10. Use the end effector of the robotic arm 1 to peel off the outer mold 10 of the flexible silicone metamaterial that has been cured in step 8).

[0122] 10) Water-soluble removal of the inner mold 8. Using the end effector of the robotic arm 1, the metamaterial, which has been peeled off from the outer mold 10 in step 9) but is still attached to the water-soluble inner mold 8, is placed in the aforementioned automated extrusion demolding device 4 with circulating water to perform water-soluble demolding of the inner mold 8. During water-soluble demolding, heating and circulating water are used as supplementary methods. The heating temperature is 90 degrees Celsius, and the water is changed every 6 hours. After sufficient hydrolysis, a flexible complex inner cavity metamaterial 6 filled with water is obtained.

[0123] 11) Drying. The flexible silicone complex cavity metamaterial 6, which has been fully dehydrated and demolded in step 10), is transferred to the automatic drying device 5 for drying using the end effector of the robotic arm 1 to obtain the prepared flexible complex cavity metamaterial 6.

[0124] The aforementioned flexible metamaterial with a complex internal cavity structure consists of two parts: an internal cavity and a neck opening, such as... Figure 2 As shown; the volume and cross-sectional area of ​​the complex internal cavity structure made of flexible metamaterial are both larger than the volume and cross-sectional area of ​​the neck opening, such as... Figure 2 As shown; the inner cavity and neck opening of the complex internal cavity structure flexible metamaterial are air-formed cavities, surrounded by a silicone envelope of a certain thickness to form the cavity shape, such as... Figure 2 As shown; the complex internal cavity structure flexible metamaterial consists of multiple internal cavities, each with a different size. These cavities are arranged regularly, with the spacing between them equal to the wall spacing between adjacent cavities, such as... Figure 2 As shown.

[0125] The complex internal cavity structure of the flexible metamaterial has a cuboid cavity shape and a cylindrical neck opening, such as... Figure 2 The neck 601 and cavity 602 of the flexible metamaterial with a complex internal cavity structure are shown. The wall thickness of the inner cavity of the flexible metamaterial with a complex internal cavity structure is 3 mm; the volume of the inner cavity of the flexible metamaterial with a complex internal cavity structure varies from 0.5 to 20 cubic millimeters; the opening diameter of the neck 601 of the flexible metamaterial with a complex internal cavity structure varies from 1 to 6 mm. The overall envelope of the metamaterial unit has a cuboid shape, as shown in the figure. Figure 1 The flexible metamaterial with a complex internal cavity structure is shown in Figure 6.

[0126] An automated fabrication apparatus for precision molding of flexible metamaterials with complex internal cavity structures, as described in this embodiment, is used. Figure 1 and Figure 6 As shown. Its features include, sequentially arranged, a robotic arm 1 with a precision clamping mold and a silicone casting device, an automated extrusion and demolding device 4 for water-soluble mold and water circulation, and an automatic drying device 5, all required in the preparation process.

[0127] The Figure 1 The water-soluble mold-forming water circulation automated extrusion demolding device 4 and the automatic drying device 5 are both arranged within the reach of the end effector of the robotic arm; the end effector is installed at the end of the robotic arm 1; the end effector of the robotic arm 1 is used to precisely grip the detachable outer mold 10, the water-soluble inner mold 8 and the silicone container; the end effector of the robotic arm 1 can also be used to transfer the flexible metamaterial 6 to be demolded and dried to the automated demolding device 4 and the automatic drying device 5;

[0128] The Figure 6The water-soluble mold-forming automatic extrusion and demolding device 4 consists of a liquid electric heating pot 16, an automatic extrusion device (including a fixed gantry frame 11, a motor 12, a coupling 13, a lead screw 14, and a moving extrusion disc 15), and a water circulation device; the water circulation device consists of an inlet pipe 17, an outlet pipe 18, and a water pump; the automatic extrusion device consists of a moving extrusion disc 15 at the extrusion contact surface and an extrusion power source;

[0129] The Figure 6 The electric heating device in the middle is an electric heating pot 16; the Figure 6 The automatic extrusion device 4 is equipped with a moving extrusion disc 15, which is a flat extrusion device. The power source of the automatic extrusion device is a motor 12 and a lead screw 14 mechanism (including a coupling 13). The motor 12 is mounted on a fixed gantry frame 11 and drives the lead screw 14 to rotate through the coupling 13. The forward and reverse rotation of the motor 12 and the lead screw 14 drives the moving extrusion disc 15 to move up and down, thereby applying extrusion force to the flexible metamaterial 6. The automatic extrusion device 4 with active water circulation can continuously apply extrusion force to the flexible metamaterial 6 with a complex internal cavity structure that is being hydrolyzed and demolded, helping the hydrolyzed polyvinyl alcohol to be discharged from the neck 601 of the complex internal cavity.

[0130] The Figure 6 The water inlet pipe 17 and water outlet pipe 18 of the water circulation device of the automatic extrusion device 4 are PVC water pipes with internal fiber reinforcement; the water pumping device is an electric pump.

[0131] The Figure 1 The automatic drying device 5 in the middle is a vacuum drying oven.

[0132] Example 3

[0133] Example 3 has the same functions as Examples 1-2, and will not be repeated for the sake of simplicity.

[0134] Example 3 differs from Examples 1-2 in that the AB silicone mixing ratio is 1:1.05; the filler added to the silicone liquid is calcium carbonate powder; the mass ratio of silicone filler added is 10%; the filling density of the polyvinyl alcohol water-soluble inner mold 8 is 12%; the number of layered pouring is 5 times; the height of each pouring is 6mm; the heating temperature is 70 degrees Celsius; and the water change time is once every 10 hours.

[0135] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

[0136] Example 4

[0137] Example 4 has the same functions as Examples 1-3, and will not be repeated for the sake of simplicity.

[0138] Example 4 differs from Examples 1-3 in that the AB silicone mixing ratio is 1:0.95; the filler added to the silicone liquid is talc; the mass ratio of silicone filler added is 40%; the filling density of the polyvinyl alcohol water-soluble inner mold 8 is 20%; the number of layered pouring is 6; the height of each pour is 5mm; the heating temperature is 95 degrees Celsius; and the water change time is once every 8 hours.

[0139] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A high-precision rapid manufacturing process for flexible metamaterials with complex internal cavity structures, applicable to the flexible metamaterials with complex internal cavity structures described in any one of claims 3-8 and the automated production device, characterized in that, The process includes the following steps: 1) Preparation of liquid silicone raw materials. Specifically, silicone is weighed using a precision balance according to the ratio, and the A and B two-component silicone is mixed. The two-component silicone is thoroughly mixed using an electric stirrer to obtain a mixed silicone liquid to be cured. 2) Prepare silica liquid containing filler. Specifically, accurately weigh the filler powder using a precision balance according to the mass of the filler to be added, add it to the silica liquid prepared in step 1), and discretize the filler components using an electric stirrer and an ultrasonic disruptor. 3) Defoaming the silica gel liquid. Specifically, place the mixed silica gel liquid from step 2) into a vacuum centrifuge to eliminate air bubbles. 4) Fabrication of a peelable outer mold and a water-soluble inner mold, as well as a fixing frame (including a bottom fixing frame and a top fixing frame for the inner mold). Specifically, an outer mold with a split-part mold design is fabricated using a rigid material via a 3D printer, and a water-soluble inner mold is fabricated using a polyvinyl alcohol material with a complex internal cavity shape via a 3D printer. A bottom fixing frame and a top fixing frame for the inner mold are also fabricated using a 3D printer to fix and limit the water-soluble mold. 5) Close the detachable outer mold. Specifically, align the outer mold prepared in step 4) with the positioning pins on the mold and close the split outer mold, and seal the joint with acetate-based acrylic adhesive tape. 6) Arrange and fix the water-soluble inner mold. Specifically, the end effector of the robotic arm is used to arrange the polyvinyl alcohol water-soluble inner mold prepared in step 4) according to the designed multiple complex inner cavity structure and place it in the bottom fixing frame and top fixing frame of the inner mold prepared in step 4) that match the complex inner cavity. After the water-soluble inner mold is tightly combined with the top fixing frame of the inner mold, the bottom fixing frame of the inner mold is removed. 7) Assemble the outer mold and the water-soluble inner mold. Specifically, the end effector of the robotic arm is used to assemble and close the water-soluble inner mold assembled in step 6) with its fixed frame and the outer mold. 8) Layered pouring and curing of silicone. Specifically, the silicone liquid after degassing in step 3) is poured into the inner and outer molds assembled in step 7) through the reserved pouring channel using the end effector of the robotic arm. The pouring and curing process is required to be repeated 2 to 5 times. 9) Remove the outer mold. Specifically, the outer mold of the metamaterial, which has been cured in step 8), is peeled off using the end effector of the robotic arm. 10) Water-soluble removal of the inner mold. Specifically, using the end effector of a robotic arm, the metamaterial, which has undergone outer mold peeling in step 9) but is still attached to the water-soluble inner mold, is placed in the automated extrusion demolding device with live water circulation as described in claims 5 and 8. The inner mold is then demolded by water filtration, aided by heating and circulating water. After thorough hydrolysis, a flexible, complex inner cavity metamaterial filled with water is obtained. 11) Drying. Specifically, the flexible silicone complex cavity metamaterial, which has been fully dehydrated and demolded in step 10), is transferred to an automatic drying device for drying to obtain the prepared flexible complex cavity metamaterial.

2. The high-precision rapid manufacturing process for a flexible metamaterial with a complex internal cavity structure according to claim 1, characterized in that, The flexible silicone material in step 1) is an AB two-component platinum silicone, and its mixing ratio can be varied from a mass ratio of 1:0.5 to 1:2; the flexible silicone material in step 2) may contain no filler or may contain one or any combination of fillers such as silica, calcium carbonate, and talc, and the mass ratio of the filler can also vary between 0% and 40%; the outer contour of the polyvinyl alcohol water-soluble inner mold in step 4) is a strictly designed complex internal cavity structure, the internal structure filling density is 15%, and the internal filling structure can be any filling structure with a supporting function, such as triangles, straight lines, grids, regular tetrahedrons, and helices; in step 5) The positioning pins of the rigid split-part mold outer mold are positioning pins and positioning pin holes with a square cross-section near the mold parting surface. The shape of the positioning pins and pin holes is not limited to rectangles, circles, triangles, etc. The adhesive tape used in step 5) is not limited to any type of acrylic adhesive tape with any substrate. The number of times the silicone is poured in layers in step 8) can be 2 to 5 times, and the thickness of each pour is 1 mm to 20 mm, depending on the specific structure. The water change cycle of the hydrolytic demolding in step 10) can be once every 1 to 24 hours, depending on the specific metamaterial structure being demolded at the same time and the water dissolution rate. The heating temperature of the hydrolytic demolding in step 10) can be 40 to 90 degrees Celsius.

3. The flexible metamaterial according to claim 1, characterized in that, The complex internal cavity flexible metamaterial consists of two parts: an inner cavity and a neck opening. The volume and cross-sectional area of ​​the inner cavity are both larger than those of the neck opening. The inner cavity and neck opening are air-formed cavities, which are supported by silicone envelopes to form the cavity shape. The flexible metamaterial is composed of multiple complex internal cavities.

4. A flexible metamaterial according to claims 1 and 3, characterized in that, The complex internal cavity is not limited to a rectangular internal cavity or a cylindrical neck opening; it can be any shape that satisfies the requirements of having a neck opening and an internal cavity structure. The complex internal cavities are arranged regularly, with the spacing between them equal to the wall thickness between adjacent cavities, and the wall thickness is 1-5 mm. Each cavity of the complex internal cavity has a different size, with an internal cavity volume between 0.5 and 20 cubic millimeters and a neck opening diameter between 1 and 6 mm. The overall envelope appearance of the metamaterial unit can be any three-dimensional shape that encloses the outer contour surface of the complex internal cavity, such as a cuboid or a sphere.

5. An automated fabrication device for precision molding of flexible complex internal cavity metamaterials, the device being applicable to the flexible complex internal cavity metamaterials described in claims 1-4, characterized in that, It includes a robotic arm with precision clamping molds and silicone casting and its end effector, an automated extrusion and demolding device with water-soluble mold and water circulation, and an automatic drying device.

6. The automated fabrication device for precision molding of flexible complex internal cavity metamaterials according to claim 5, characterized in that, The end effector is installed at the end of the robotic arm; the water-soluble mold-forming water circulation automated extrusion demolding device and the automatic drying device are both arranged within the reach of the end effector of the robotic arm.

7. The automated fabrication device for precision molding of flexible complex internal cavity metamaterials according to claims 5 and 6, characterized in that, The end effector of the robotic arm is used to precisely grip the detachable outer mold, the water-soluble inner mold, and the silicone container; the end effector can also be used to transfer the flexible metamaterial to be demolded and dried to an automated demolding device and an automated drying device.

8. The automated fabrication device for precision molding of flexible complex internal cavity metamaterials according to claim 5, characterized in that, The water-soluble mold-forming automatic extrusion and demolding device consists of a liquid electric heating device, an automatic extrusion device, and a water circulation device; the electric heating device can be any container that can heat water or other liquids, including electric heating pots, gas heating pots, and steam heating pots, etc. The automatic extrusion device consists of an extrusion contact surface moving extrusion disc and an extrusion power source; the contact surface moving extrusion disc of the automatic extrusion device can be a flat extrusion device or any device that can apply surface pressure to the metamaterial to be demolded; the power source of the automatic extrusion device can be any mechanism that can perform linear motion or extrusion motion, such as a motor screw, hydraulic actuator, or pneumatic cylinder. The water circulation device consists of an inlet pipe, an outlet pipe, and a pumping device. The inlet pipe and outlet pipe can be any type of pipe for transporting liquids, such as rubber pipes, plastic pipes, or nylon pipes. The pumping device can be any type of pump that can transport liquids, such as an electric pump, a pneumatic diaphragm pump, a pneumatic piston pump, or a hydraulic motor pump.

9. The automated fabrication device for precision molding of flexible complex internal cavity metamaterials according to claim 5, characterized in that, The automatic drying device is not limited to vacuum drying ovens, forced-air drying ovens, and ovens; it can be any type of equipment capable of drying objects.

Images