A reconfigurable foldable metamorphic structure based on 3D printing and a manufacturing method thereof

Abstract

The application discloses a reconfigurable foldable and deployable structure based on 3D printing and a manufacturing method thereof, and belongs to the field of additive manufacturing and intelligent structure design. The application solves the problems of existing foldable and deployable structures, such as dependence on mechanical driving and complex structure. The structure is composed of two layers of smart material plates with the same thickness. The structure combines paper cutting strategy and 3D printing to form an initial configuration with beam-hole structure in the printing stage, and realizes active foldable and deployable reconfiguration under external physical field stimulation. The manufacturing method comprises the following steps: selecting anisotropic smart material according to application scenarios, determining design parameters and beam-hole paper cutting patterns based on the theory of large deformation double-layer beam, generating 3D printing vector trajectories and integrally forming and preparing. The application does not need complex transmission assembly, and has the advantages of lightweight structure, controllable deformation, calculable design parameters, adaptation to multiple application scenarios, and application in the fields of foldable and deployable structures and flexible mechanisms.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing and intelligent structure design technology, specifically relating to a reconfigurable foldable and deformable structure based on 3D printing and its manufacturing method. Background Technology

[0002] With the development of smart materials, additive manufacturing technology, and structural design theory, artificially designed smart structures and mechanisms have made significant progress in fields such as aerospace, soft robotics, medical devices, and intelligent sensing. By rationally designing smart materials and their structural forms, the structural morphology can be actively controlled under external physical field stimuli such as temperature, electric, magnetic, light, and sound fields. This allows the structure to undergo expected reconfigurable deformation after experiencing external field stimuli, thereby adapting to specific application scenarios.

[0003] Existing reconfigurable deformable structures mostly rely on traditional mechanical transmission mechanisms or multi-component assembly methods, which generally suffer from problems such as complex structures, large transmission systems, high energy consumption, complex control systems, and susceptibility to wear during long-term use. Although some research has improved these problems by introducing flexible mechanisms or smart materials, the current technological system still lacks a reconfigurable deformable structure and its manufacturing method that can simultaneously achieve lightweight structure, one-piece molding, simplified design and manufacturing processes, and excellent folding and unfolding performance and controllable deformation capabilities. Summary of the Invention

[0004] To address the shortcomings of existing reconfigurable folding and deformable structures, such as structural complexity, cumbersome manufacturing and assembly processes, large system mass, and high control difficulty, this invention proposes a 3D-printed reconfigurable folding and deformable structure and its manufacturing method, based on the intrinsic strain generated by intelligent responsive materials under external physical field stimulation.

[0005] This invention integrates reconfigurable folding and deformation logic into the structural material itself. It designs the initial configuration of the reconfigurable folding and deformation structure using a paper-cut pattern with beam-hole structure. Combined with the characteristic of the double-layer structure to generate controllable large deformation under external physical field stimulation, it realizes the active reconstruction of the structure under specific field stimulation conditions, thereby constructing a lightweight and integrally formed reconfigurable folding and deformation structure.

[0006] By combining the characteristics of the double-layer structure to produce controllable large deformation under external physical field stimulation, the structure can be actively reconstructed under specific field stimulation conditions, thereby constructing a lightweight and integrally molded reconfigurable folding and deforming structure.

[0007] To achieve the above objectives, this invention proposes a method for manufacturing a reconfigurable, unfoldable, and deformable structure based on 3D printing, comprising the following steps:

[0008] 1) Based on the external physical field environment under the predetermined application scenario, determine the folding and deformation target of the reconfigurable folding and deformation structure, and select smart materials with anisotropic response characteristics;

[0009] 2) Based on the theory of large deformation double-layer beams, determine the design parameter values ​​of the reconfigurable folding deformation structure and the paper-cutting pattern with beam-hole structure;

[0010] 3) Generate continuous 3D printing vector trajectories based on the design parameter values ​​of the reconfigurable folding and deforming structure and the paper-cutting pattern; based on the 3D printing vector trajectory, prepare the reconfigurable folding and deforming structure by 3D printing, and realize large-volume reconfigurable folding and deforming under the corresponding external physical field stimulation.

[0011] Furthermore, in step 1), the folding and deformation targets of the reconfigurable folding and deformation structure include: reconfigurable folding and deformation volume ratio, cyclic capacity, and load-bearing capacity;

[0012] The reconfigurable unfolded deformation volume ratio is obtained by comparing the envelope volume after deformation with the envelope volume before deformation.

[0013] Furthermore, in step 1), the smart material is a liquid crystal elastomer, shape memory polymer, or other polymeric material that generates intrinsic strain under external physical field stimulation.

[0014] Furthermore, when the smart material is a liquid crystal elastomer, it is prepared using direct ink writing 3D printing technology; when the smart material is a shape memory polymer, it is prepared using fused deposition modeling 3D printing technology.

[0015] Furthermore, in step 2), the determination of the design parameter values ​​for the reconfigurable folded deformation structure based on the large deformation double-layer beam theory specifically involves:

[0016] First, the radius of curvature of the reconfigurable folding and deformable structure after deformation is determined based on the preset scenario design.

[0017] Then, based on the radius of curvature and the number of beam-hole structures that can be reconfigured and deformed, the length and width of the initial configuration are designed.

[0018] Finally, the material thickness of the upper and lower layers of the initial configuration of the reconfigurable folding deformation structure is determined based on the radius of curvature formula, i.e., the height of the initial configuration.

[0019] The formula for the radius of curvature is:

[0020] ;

[0021] in, This represents the radius of curvature of a double-layer beam after large deformation. and Let these represent the elastic moduli of the lower and upper layers after reconfigurable unfolding deformation, respectively. and These represent the thicknesses of the upper and lower layers of material, respectively. , and These represent the expansion rates of the lower and upper layers after reconfigurable folding and deformation, respectively.

[0022] Furthermore, in step 2), the paper-cut pattern with a beam-hole structure is provided, wherein the beams meet the dimensional requirements of the large deformation double-layer beam theory.

[0023] Furthermore, in step 3), the reconfigurable unfoldable structure prepared by 3D printing is specifically divided into upper and lower layers perpendicular to the printing plane. Each layer is composed of multiple printing layers, and each printing layer has the same material arrangement and printing direction.

[0024] Furthermore, the printing direction specifically refers to the fact that the printing directions of the lower and upper layers are perpendicular to each other, and the printing direction is parallel or perpendicular to the structural edge of the reconfigurable unfoldable deformation structure.

[0025] A 3D-printed reconfigurable deformable structure, obtained by any of the manufacturing methods described above, is composed of two layers of smart materials and is capable of generating a controllable reconfigurable unfolding deformation response under external physical field stimulation.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. This invention selects suitable smart materials according to the actual application environment, and embeds nonlinear deformation logic into the smart structure through the printing path to realize the integrated design and manufacturing of reconfigurable deformable structure products;

[0028] 2. This invention uses 3D printing technology to prepare a reconfigurable folding and deformable structure, which can be reconfigured and deformed under external field stimulation to achieve the desired reconfigurable folding and deformable structure. Compared with traditional reconfigurable folding and deformable structures, the preparation process is simple and lightweight, while also meeting functional requirements.

[0029] 3. This invention determines design parameters based on the large deformation double-layer beam theory, which can accurately determine the radius of curvature of the structural deformation. Combined with external physical field stimulation, it achieves controllable and reconfigurable folding deformation, and the design parameters are calculable.

[0030] 4. The beam structure in the paper-cut pattern of this invention strictly matches the size requirements of the large deformation double-layer beam theory, designs a suitable 3D printing planning path and specific field stimulation, realizes the reconfigurable deformation requirements under different folding scales, deformation models and usage scenarios, has the advantages of low cost and short design and manufacturing cycle, and is suitable for a variety of application fields such as folding structures, flexible mechanisms, and intelligent equipment. Attached Figure Description

[0031] Figure 1 This is a flowchart of a method for manufacturing a reconfigurable unfoldable and deformable structure based on 3D printing according to the present invention.

[0032] Figure 2 This is a schematic diagram of the deformation theory of the double-layer beam structure in this invention;

[0033] Figure 3 This is a schematic diagram of the unfolded volume analysis of a reconfigurable deformable structure according to an embodiment of the present invention;

[0034] Figure 4 The reconfigurable folding and deformation structure designed based on liquid crystal elastomer smart material in Embodiment 1 of the present invention is shown in (a) as a schematic diagram of printing path planning, (b) 3D printed double-layer reconfigurable folding and deformation structure, and (c) the reconfigurable folding and deformation structure after deformation (physical image).

[0035] Figure 5 This is an example of an adaptive reconfigurable folding gripper made from the reconfigurable folding deformation structure of the liquid crystal elastomer in Embodiment 1 of the present invention.

[0036] Figure 6 This is a diagram showing the relationship between the weight ratio and geometric dimensions of the reconfigurable unfolding gripper in Embodiment 1 of the present invention;

[0037] Figure 7 This is a comparison image of the reconfigurable unfolding deformation structure designed based on shape memory polymer (polylactic acid) in Embodiment 2 of the present invention before and after deformation;

[0038] Figure 8 The diagram shows the load-bearing capacity test of the reconfigurable folding and deforming structure in Embodiment 2 of the present invention, where (a) is the test experiment and (b) is the experimental result diagram.

[0039] Figure 9 These are a series of reconfigurable folding and deformation structure diagrams designed according to the manufacturing method of this invention. Detailed Implementation

[0040] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the following embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Without departing from the technical concept of the present invention, those skilled in the art can make various modifications or substitutions to the embodiments, all of which should fall within the scope of protection of the present invention.

[0041] This invention provides a reconfigurable folding and deformable structure based on 3D printing and its manufacturing method, the flowchart of which is shown below. Figure 1 As shown.

[0042] 1) Based on the external physical field environment under the predetermined application scenario, determine the folding and deformation target of the reconfigurable folding and deformation structure, and select smart materials with anisotropic response characteristics;

[0043] 2) Based on the theory of large deformation double-layer beams, determine the design parameter values ​​of the reconfigurable folding deformation structure and the paper-cutting pattern with beam-hole structure;

[0044] 3) Generate continuous 3D printing vector trajectories based on the design parameter values ​​of the reconfigurable folding and deforming structure and the paper-cutting pattern; based on the 3D printing vector trajectory, prepare the reconfigurable folding and deforming structure by 3D printing, and realize large-volume reconfigurable folding and deforming under the corresponding external physical field stimulation.

[0045] like Figure 2 As shown, this invention employs the large deformation double-layer beam theory to describe the bending deformation behavior of a double-layer beam structure under external physical field stimulation. The double-layer beam structure consists of an upper layer material and a lower layer material. When an external physical field is applied, the two layers of material generate intrinsic strains of different amplitudes and directions. Due to the interlayer bonding constraint, the double-layer beam structure as a whole undergoes bending deformation.

[0046] By introducing the elastic modulus, thickness parameters, and intrinsic strain parameters of the two layers of materials, a quantitative relationship model between the curvature of the double-layer beam structure and external physical field stimuli can be established, thus providing a theoretical basis for the geometric design of the double-layer beam structure and the overall configuration design of the subsequent reconfigurable deformable structure.

[0047] Example 1:

[0048] Temperature-driven liquid crystal elastomer recoverable and reconfigurable unfolding deformation structure

[0049] This embodiment provides a temperature-driven liquid crystal elastomer (LCE) recoverable and reconfigurable folding deformation structure. A liquid crystal elastomer material with anisotropic response to temperature is selected as the constituent material of the bilayer beam structure. By controlling the molecular orientation of the liquid crystal elastomer during the printing process, it generates reversible anisotropic intrinsic strain during temperature changes. After reconfigurable folding deformation, the expansion rates of the lower and upper layers are 0.76 and 1.14, respectively, and the elastic moduli of the lower and upper layers are 0.3 MPa and 0.1 MPa, respectively.

[0050] Based on the theory of large deformation double-layer beams, the bending deformation behavior of liquid crystal elastomer double-layer beam structures under temperature field stimulation is analyzed, and the design parameter values ​​of recoverable and reconfigurable folding deformation structures and paper-cutting patterns with beam-hole structures are determined.

[0051] First, based on the preset scenario design, the radius of curvature of the recoverable and reconfigurable unfolded deformable structure after deformation is determined to be... ;

[0052] Then, based on the radius of curvature and the number of beam-hole structure designs that can recover and reconfigure folded deformation, the length of the initial configuration is designed. Hekuan ;

[0053] Finally, based on the radius of curvature formula, the material thicknesses of the upper and lower layers of the initial configuration of the recoverable and reconfigurable folded deformation structure are determined as follows: Total thickness The initial configuration's high ;

[0054] like Figure 2 As shown, the formula for the radius of curvature is:

[0055] ;

[0056] in, This represents the radius of curvature of a double-layer beam after large deformation. and Let these represent the elastic moduli of the lower and upper layers after reconfigurable large deformation. and These represent the thicknesses of the upper and lower layers of material, respectively. , and These represent the expansion rates of the lower and upper layers after reconfigurable folding deformation, respectively;

[0057] The paper-cut pattern of the beam-hole structure is specifically in the form of a rectangular frame, consisting of an outer frame and multiple internal horizontal beams. These beams are parallel and evenly distributed, forming equally spaced rectangular perforated channels between them. The width of the beams... .

[0058] Based on the design parameter values ​​of the recoverable and reconfigurable folding and deforming structure and the paper-cutting pattern, a continuous 3D printing vector trajectory is generated. Based on the 3D printing vector trajectory, the recoverable and reconfigurable folding and deforming structure is fabricated by 3D printing. The recoverable and reconfigurable folding and deforming structure achieves large-volume reconfigurable folding and deforming under corresponding external physical field stimuli, specifically:

[0059] A reconfigurable deformable structure model is constructed using computer-aided design software, and printing path planning is performed to generate corresponding G-code. Based on the G-code, the initial configuration of the reconfigurable deformable structure is prepared using a dual-material 3D printing device.

[0060] The 3D printing technology mentioned above is direct ink writing printing, which requires the preparation of liquid crystal elastomer printing ink before printing.

[0061] The liquid crystal elastomer printing ink is prepared by chemical reaction of RM257, EDDET and dipropylamine in a molar ratio of 14:12:1.

[0062] Among them, the parameters for direct ink writing 3D printing technology are: printing needle 0.8 The printing temperature is 40 degrees Celsius. The printing speed is 5 The printing air pressure is 4.5. .

[0063] Among them, the printing process parameters for the recoverable and reconfigurable folding and deforming structure are as follows: printing linewidth 0.35. Print height 0.3 .

[0064] When a temperature field is applied to the initial configuration of the recoverable and reconfigurable folding deformation structure, the liquid crystal elastomer material undergoes a reversible phase transition, driving the structure to bend or fold. When the temperature field is removed, the structure can return to its initial configuration, realizing a reversible and repeatable reconfigurable deformation process.

[0065] Among them, the reconfigurable unfolded deformation volume ratio is:

[0066] In the formula, This indicates the unfolding ratio of a reconfigurable deformable structure. This represents the volume of the deformed envelope. This represents the envelope volume before deformation. For example... Figure 3 As shown, and These are the deformation calculation parameters after reconstruction. , and These are the length, width, and height of the initial configuration, respectively.

[0067] like Figure 4 As shown in (a), the material arrangement of each printed layer of the recoverable and reconfigurable folding and deformable structure is arranged in parallel straight lines for printing, with no gaps in the printing; the printing directions of the lower and upper layers are perpendicular to each other, and the printing directions are parallel or perpendicular to the edges of the structure.

[0068] In this embodiment, Figure 4 A reconfigurable deformable structure with recoverable deformation capability under temperature field stimulation was obtained by using a liquid crystal elastomer material system. The before and after deformation images are shown below. Figure 4 As shown in (b) and (c).

[0069] Based on the recoverable and reconfigurable unfolding characteristics of this example, it can be fabricated into an adaptive reconfigurable unfolding gripper capable of grasping objects of various shapes, such as... Figure 5 As shown; Figure 6 It also has a large gripping ratio and the advantages of low cost, simple design and manufacturing process and lightweight body.

[0070] Example 2:

[0071] Temperature field driven shape memory polymer reconfigurable deformable structures

[0072] This embodiment provides a temperature-driven, non-recoverable, reconfigurable folding deformation structure based on a shape memory polymer (SMP). Polylactic acid (PLA), a shape memory polymer with shape memory effect, is selected as the constituent material of the double-layer beam structure. Through material selection or structural design, the double-layer beam structure generates differentiated intrinsic strains under temperature stimulation. After reconfigurable folding deformation, the expansion rates of the lower and upper layers are 0.93 and 1.04, respectively, and the elastic moduli of the lower and upper layers after reconfigurable folding deformation are 5. and 3 .

[0073] Based on the theory of large deformation double-layer beams, the deformation behavior of shape memory polymer double-layer beam structures under temperature field stimulation is analyzed, and the design parameter values ​​of irreversible reconfigurable folding deformation structures and paper-cutting patterns with beam-hole structures are determined.

[0074] First, based on the preset scenario design, the radius of curvature of the non-recoverable reconfigurable folding deformation structure after deformation is determined to be 13mm.

[0075] Then, based on the radius of curvature and the number of beam-hole structure designs for non-recoverable reconfigurable folded deformation structures, the length of the initial configuration is designed. Hekuan ;

[0076] Finally, based on the radius of curvature formula of Example 1, the material thicknesses of the upper and lower layers of the initial configuration of the irreversible reconfigurable folding deformation structure are determined as follows: Total thickness The initial configuration's high ;

[0077] The paper-cut pattern of the beam-hole structure is specifically in the form of a rectangular frame, consisting of an outer frame and multiple internal horizontal beams. These beams are parallel and evenly distributed, forming equally spaced rectangular perforated channels between them. The width of the beams... .

[0078] Based on the design parameter values ​​of the irreversible reconfigurable folding and deformation structure and the paper-cutting pattern, a continuous 3D printing vector trajectory is generated. Based on the 3D printing vector trajectory, the irreversible reconfigurable folding and deformation structure is fabricated by 3D printing. The irreversible reconfigurable folding and deformation structure achieves large-volume reconfigurable folding and deformation under corresponding external physical field stimuli, specifically as follows:

[0079] A reconfigurable deformable structure model is constructed using computer-aided design software, and printing path planning is performed to generate corresponding G-code. Based on the G-code, the initial configuration of the reconfigurable deformable structure is prepared using a dual-material 3D printing device.

[0080] The 3D printing technology mentioned is fused deposition modeling (FDM) 3D printing, and the material is commercial polylactic acid roll material.

[0081] Among them, the printing process parameters for the reconfigurable deformable structure are: printing linewidth 0.4. Print height 0.01 .

[0082] When a temperature field is applied to the initial configuration of the non-recoverable reconfigurable folding deformation structure, the double-beam structure bends and then folds. After reaching the expected deformation configuration, the shape memory polymer is brought into a fixed shape state by temperature field control, so that the structure retains the deformed configuration after the external stimulus is removed, achieving a non-recoverable but retainable reconfigurable deformation effect.

[0083] Among them, the reconfigurable unfolding ratio is .

[0084] In this embodiment, Figure 7 The non-recoverable reconfigurable folding deformation structure shown is achieved using a shape memory polymer material system, thus obtaining a non-recoverable but maintainable deformation configuration after being stimulated by a temperature field. The polylactic acid material used has a modulus of 3000-4000 MPa, therefore it has a large load-bearing capacity after reconstruction, as shown in the figure. Figure 8 As shown.

[0085] Compared with Example 1, the main difference of Example 2 lies in the type of smart material used and its deformation recovery mechanism: Example 1 utilizes the reversible thermal response characteristics of liquid crystal elastomers to achieve repeated reconfigurable deformation of the structure; Example 2 utilizes the phase change locking characteristics of shape memory polymers to achieve stable retention after deformation and high load-bearing capacity.

[0086] By selecting different smart materials, this invention can realize different types of reconfigurable deformation functions within the same manufacturing framework, demonstrating the versatility and flexibility of the technical solution of this invention.

[0087] Furthermore, based on this manufacturing method, some reconfigurable deformable structures with a large folding-to-unfold ratio have also been designed, such as... Figure 9 As shown, this demonstrates the universality of the method.

[0088] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0089] It should be understood that this application is not limited to the computational process described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for manufacturing a reconfigurable folding and deformable structure based on 3D printing, characterized in that, Includes the following steps: 1) Based on the external physical field environment under the predetermined application scenario, determine the folding and deformation target of the reconfigurable folding and deformation structure, and select smart materials with anisotropic response characteristics; 2) Based on the theory of large deformation double-layer beams, determine the design parameter values ​​of the reconfigurable folding deformation structure and the paper-cutting pattern with beam-hole structure; 3) Generate continuous 3D printing vector trajectories based on the design parameter values ​​of the reconfigurable folding and deforming structure and the paper-cutting pattern; based on the 3D printing vector trajectory, prepare the reconfigurable folding and deforming structure by 3D printing, and realize large-volume reconfigurable folding and deforming under the corresponding external physical field stimulation; In step 2), the specific steps for determining the design parameter values ​​of the reconfigurable folded deformation structure based on the large deformation double-layer beam theory are as follows: First, the radius of curvature of the reconfigurable folding and deformable structure after deformation is determined based on the preset scenario design. Then, based on the radius of curvature and the number of beam-hole structures that can be reconfigured and deformed, the length and width of the initial configuration are designed. Finally, the material thickness of the upper and lower layers of the initial configuration of the reconfigurable folding deformation structure is determined based on the radius of curvature formula, i.e., the height of the initial configuration. The formula for the radius of curvature is: ； in, This represents the radius of curvature of a double-layer beam after large deformation. and Let represent the elastic moduli of the lower and upper layers after reconfigurable folding deformation, respectively. and These represent the thicknesses of the upper and lower layers of material, respectively. , and These represent the expansion rates of the lower and upper layers after reconfigurable folding deformation, respectively; In step 2), the paper-cut pattern with a beam-hole structure is provided, wherein the beams meet the dimensional requirements of the large deformation double-layer beam theory.

2. The manufacturing method according to claim 1, characterized in that, In step 1), the folding and deformation targets of the reconfigurable folding and deformation structure include: reconfigurable folding and deformation volume ratio, cyclic capacity, and load-bearing capacity; The reconfigurable unfolded deformation volume ratio is obtained by comparing the envelope volume after deformation with the envelope volume before deformation.

3. The manufacturing method according to claim 1, characterized in that, In step 1), the smart material is a liquid crystal elastomer, shape memory polymer, or other polymeric material that generates intrinsic strain under external physical field stimulation.

4. The manufacturing method according to claim 3, characterized in that, When the smart material is a liquid crystal elastomer, it is prepared using direct ink writing 3D printing technology; when the smart material is a shape memory polymer, it is prepared using fused deposition modeling 3D printing technology.

5. The manufacturing method according to claim 1, characterized in that, In step 3), the reconfigurable unfoldable structure prepared by 3D printing is specifically divided into upper and lower layers perpendicular to the printing plane. Each layer is composed of multiple printing layers, and each printing layer has the same material arrangement and printing direction.

6. The manufacturing method according to claim 5, characterized in that, Specifically, the printing direction is as follows: the printing directions of the lower and upper layers are perpendicular to each other, and the printing direction is parallel or perpendicular to the structural edge of the reconfigurable folding and deformable structure.

7. A reconfigurable deformable structure based on 3D printing, characterized in that, The reconfigurable deformable structure, obtained by any one of the manufacturing methods described in claims 1-6, is composed of two layers of smart materials and is capable of generating a controllable reconfigurable unfolding deformation response under external physical field stimulation.

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