Accurate temperature control extensible structure based on 4D printing and use method of accurate temperature control extensible structure

Abstract

The invention discloses a precise temperature control extensible structure based on 4D printing and a using method thereof. The precise temperature control extensible structure comprises a top plate; the temperature control extensible unit is connected with the top plate; the temperature control deployable unit comprises an annular support; the bulges are arranged on the annular support; the double-material arches are arranged on the two adjacent bulges; and the supporting rod is arranged on the double-material arch. Through ingenious combination of the elastomer and the shape memory polymer in the bi-material arch, the expandable structure can sensitively sense the environment temperature change. When the temperature is lower than the glass transition temperature of the shape memory polymer, the structure can stably maintain a deformation state; once entering an environment with the temperature higher than the temperature, the device can be automatically and accurately expanded step by step from a compressed state according to a preset material ratio and structural design. Due to the self-adaptive capability, high flexibility is achieved under the complex and changeable working conditions, and an extra complex control system is not needed.

Description

Technical Field

[0001] The present invention relates to a precision temperature-controlled deployable structure based on 4D printing and its usage method, belonging to the fields of 4D printing technology and shape memory polymers. Technical Background

[0002] With the rapid development of modern engineering technology, the demand for structures with special functions and intelligent response characteristics is increasing day by day. In many fields such as aerospace, construction engineering, and biomedicine, deployable structures have attracted much attention because they can change their shapes and properties under different working conditions. Traditional deployable structures usually achieve deployment and retraction actions based on mechanical connections or hydraulic drives. However, these methods often have problems such as complex structures, slow response speeds, limited precision, and insufficient reliability.

[0003] In recent years, the rise of 3D printing technology has provided a new way for the manufacturing of deployable structures, enabling the rapid prototyping of complex-shaped structures. At the same time, the emergence of the concept of 4D printing further expands the application scope of 3D printing. By introducing intelligent materials, the printed structures can change their shapes or properties over time under external stimuli (such as temperature, humidity, light, etc.). Among many stimulus response factors, temperature has become a research hotspot because it is easy to control and is ubiquitous in various environments.

[0004] As a typical intelligent material, shape memory polymer has a unique shape memory effect, that is, it can recover from a temporary shape to the original shape under specific temperature conditions. Combining shape memory polymer with elastomer to form a bi-material system and applying it to deployable structures can give full play to the advantages of both. The elastomer provides the flexibility and elastic deformation ability of the structure, while the shape memory polymer endows the structure with shape recoverability under temperature stimuli. This bi-material arch structure can maintain the deformed state at low temperatures, and when the temperature rises above the glass transition temperature of the shape memory polymer, it can achieve precise shape recovery according to different material compositions and structure designs, thereby realizing the precise deployment action of the deployable structure. The research and development of a precision temperature-controlled deployable structure based on 4D printing is expected to overcome many limitations of traditional deployable structures, provide a new and efficient structural solution for related fields, and have broad application prospects and important research value in future engineering practices. Summary of the Invention

[0005] To improve the above problems, the present invention proposes a precision temperature-controlled deployable structure based on 4D printing.

[0006] To achieve the above effects, the present invention adopts the following technical solutions:

[0007] A precision temperature-controlled deployable structure based on 4D printing, comprising:

[0008] Top plate;

[0009] And a temperature-controlled deployable unit connected to the top plate;

[0010] The temperature-controlled deployable unit includes:

[0011] Annular support;

[0012] A plurality of protrusions provided on the annular support;

[0013] A bimaterial arch mounted on two adjacent protrusions;

[0014] And a strut provided on the bimaterial arch.

[0015] The bimaterial arch is a cosine, circular arc or inclined beam.

[0016] The bimaterial arch is composed of a first material and a second material, and the trends of the elastic moduli of the first material and the second material changing with temperature are different.

[0017] The bimaterial arch includes:

[0018] A passive layer composed of the first material;

[0019] An active layer composed of the second material;

[0020] The elastic modulus of the first material changes with temperature less than that of the second material.

[0021] The active layer is attached to the passive layer.

[0022] The first material is Agilus30, and the second material is RGD8525-DM;

[0023] Or, the first material is TPU (thermoplastic polyurethane elastomer rubber), and the second material is PLA (polylactic acid).

[0024] The bimaterial arch close to the top plate is connected to the top plate through the strut.

[0025] There are multiple temperature-controlled deployable units, and two adjacent temperature-controlled deployable units are connected through the strut.

[0026] The usage method of the 4D printing-based precise temperature-controlled deployable structure includes the following steps:

[0027] Step 1: Place the 4D printing-based precise temperature-controlled deployable structure in an environment below the glass transition temperature of the second material. The environment can be air, vacuum, or liquid. Fix the bottom annular support on a plane and apply an axial load to the top plate to cause the bimaterial arches of all layers to undergo snap-through buckling.

[0028] Step 2: Remove the axial load applied to the top plate to make the bimaterial arches of all layers stable in the buckled position.

[0029] Step 3: Move the 4D printing-based precise temperature-controlled deployable structure to an environment above the glass transition temperature of the second material. The second material undergoes a phase change under environmental thermal stimulation, and all the bimaterial arches snap back to the pre-compression state when reaching the critical deployment temperature.

[0030] A 4D printing-based precise temperature-controlled deployable structure proposed by the present invention has the following advantages:

[0031] (1) Intelligent response and adaptability: The 4D printing-based precise temperature-controlled deployable structure of the present invention exhibits excellent intelligent response characteristics. Through the ingenious combination of the elastomer and shape memory polymer in the bimaterial arch, the deployable structure can sensitively sense environmental temperature changes. When the temperature is below the glass transition temperature of the shape memory polymer, the structure can stably maintain the deformed state; once it enters an environment with a temperature higher than this, it can automatically and precisely expand from the compressed state step by step according to the preset material ratio and structure design. This adaptability endows it with high flexibility under complex working conditions, eliminates the need for additional complex control systems, greatly improves the intelligent level of the structure, and provides an ideal solution for the adaptive structure design in fields such as intelligent buildings and aerospace.

[0032] (2) Precise shape control and repeatability: Since the proportion of the elastomer and shape memory polymer in the bimaterial arch of the deployable structure is easily adjustable, precise control of the critical deployment temperature is achieved. At the same time, the dimensions during deployment and compression are deterministic and completely determined by the geometric dimensions of the arch. The precise shape recovery sequence and degree have high repeatability. Whether it is multiple expansion and retraction cycles or in different usage scenarios, the shape change of the structure can be ensured to be stable and reliable. This has irreplaceable advantages for some application scenarios with extremely high shape accuracy requirements, such as the protective shell of precision instruments and the support structure of high-resolution optical equipment, and can effectively reduce the performance loss caused by structural deformation errors.

[0033] (3) Multi - environmental adaptability: This deployable structure can work properly in various environments such as air, vacuum, or liquid. The environmental temperature, as a key factor triggering deformation, can effectively play its role in different medium environments. This extensive environmental adaptability enables it to break through the limitations of traditional structures on the usage scenarios. Whether it is in construction engineering applications in the conventional atmospheric environment, or in aerospace, ocean engineering and other fields in extreme space vacuum environments or special liquid medium environments, it can show good performance, greatly expanding its application scope and market potential. Description of the Drawings

[0034] Figure 1 Response of the dual - material arch of a precision temperature - controlled deployable structure based on 4D printing according to the present invention at different temperatures;

[0035] Figure 2 Relationship between the elastic moduli of the first material and the second material in a precision temperature - controlled deployable structure based on 4D printing according to the present invention varying with temperature;

[0036] Figure 3 Basic unit of the dual - material arch that constitutes the core deformation area of a precision temperature - controlled deployable structure based on 4D printing according to the present invention;

[0037] Figure 4 Schematic diagram of a precision temperature - controlled deployable structure based on 4D printing according to the present invention;

[0038] Figure 5 Schematic diagram of applying an axial load to cause the dual - material arch to undergo snap - through buckling in the implementation steps of a precision temperature - controlled deployable structure based on 4D printing according to the present invention;

[0039] Figure 6 Schematic diagram of applying an external environmental stimulus to cause the dual - material arch to jump back to the state before compression when reaching the critical deployment temperature in the implementation steps of a precision temperature - controlled deployable structure based on 4D printing according to the present invention;

[0040] Figure 7 Finite - element simulation stress nephogram and curve of the displacement of the top plate 5 varying with temperature in step three of the usage method of a precision temperature - controlled deployable structure based on 4D printing according to the present invention.

[0041] Among them, 1 - dual - material arch, 2 - annular support, 3 - protrusion, 4 - strut, 5 - top plate, T - critical deployment temperature. Detailed Embodiment

[0042] The following will describe the embodiments of the present invention in detail in conjunction with the drawings.

[0043] As Figure 4As shown in the figure, a precisely temperature-controlled deployable structure based on 4D printing includes a bimaterial arch 1, a circular support 2, protrusions 3, struts 4, and a top plate 5. The bimaterial arch 1 is the core deformation region, and the circular support 2, protrusions 3, struts 4, and top plate 5 are auxiliary support structures, providing a stable support framework for the entire deployable structure to ensure the integrity and reliability of the structure in different states.

[0044] As Figure 4 shown in the figure, a precisely temperature-controlled deployable structure based on 4D printing includes: a top plate 5; and a temperature-controlled deployable unit connected to the top plate 5. The temperature-controlled deployable unit includes: a circular support 2; a plurality of protrusions 3 provided on the circular support 2; a bimaterial arch 1 installed on adjacent two protrusions 3; and struts 4 provided on the bimaterial arch 1. There are a plurality of temperature-controlled deployable units, and adjacent two temperature-controlled deployable units are connected by struts 4. The bimaterial arch 1 close to the top plate 5 is connected to the top plate 5 by a strut 4.

[0045] A precisely temperature-controlled deployable structure based on 4D printing proposed by the present invention, as Figure 4 shown in the figure, includes a bimaterial arch 1, a circular support 2, protrusions 3, struts 4, and a top plate 5. The bimaterial arch 1 is the core deformation region, and the circular support 2, protrusions 3, struts 4, and top plate 5 are auxiliary support structures. The basic unit formed by the bimaterial arch 1 in the core deformation region is as Figure 3 shown in the figure, which is composed of a first material and a second material. The trends of the elastic moduli of the first material and the second material changing with temperature are different, as Figure 2 shown in the figure. The bimaterial arch 1 includes: a passive layer composed of the first material; an active layer composed of the second material; wherein the area ratio of the second material to the first material is 0.435. The trend of the elastic modulus of the first material changing with temperature is smaller than that of the second material. The active layer is attached to the passive layer. The first material is Agilus30, and the second material is RGD8525-DM; or, the first material is thermoplastic polyurethane elastomer rubber, and the second material is polylactic acid.

[0046] Figure 3 The basic unit shown in the figure exhibits bistability at low temperature and monostability at high temperature, as Figure 1 shown in the figure. It can be seen that at low temperature, its displacement-strain energy curve has two minima, corresponding to two stable states. At high temperature, its displacement-strain energy curve has only one minimum, corresponding to a single stable state.

[0047] A precisely temperature-controlled deployable structure based on 4D printing proposed by the present invention, the specific implementation process includes the following steps:

[0048] Step 1: Place the precisely temperature-controlled deployable structure based on 4D printing in an environment below the glass transition temperature of the second material. Fix the bottom annular support 2 on a plane, and apply an axial load to the top plate 5 to cause the bilayer arches 1 of all layers to undergo snap-through buckling, as Figure 5 shown;

[0049] Step 2: Remove the axial load applied to the top plate 5 to stabilize the bilayer arches 1 of all layers at the post-buckling position;

[0050] Step 3: Move the precisely temperature-controlled deployable structure based on 4D printing to an environment above the glass transition temperature of the second material. The second material undergoes a phase change under environmental thermal stimulation, and all the bilayer arches 1 snap back to the pre-compression state when reaching the critical deployment temperature, as Figure 6 shown.

[0051] When the precisely temperature-controlled deployable structure based on 4D printing described in the present invention is compressed, it is compressed to one-half of its original length, as Figure 5 shown. The environmental temperature can be an air, vacuum, or liquid environment.

[0052] Figure 7 It is the finite element simulation stress nephogram of Step 3 and the curve of the displacement of the top plate 5 varying with temperature in the method for using the precisely temperature-controlled deployable structure based on 4D printing described in the present invention.

Claims

1. A precision temperature-controlled deployable structure based on 4D printing, characterized in that: Comprising: Top plate (5); And a temperature-controlled deployable unit connected to the top plate (5); The temperature-controlled deployable unit includes: Annular support (2); A plurality of protrusions (3) provided on the annular support (2); Bi-material arches (1) mounted on adjacent protrusions (3); And struts (4) provided on the bi-material arches (1).

2. The precision temperature-controlled deployable structure based on 4D printing according to claim 1, wherein: The bi-material arches (1) are cosine, circular arc or inclined beams.

3. The precision temperature-controlled deployable structure based on 4D printing according to claim 2, characterized in that: The bi-material arches (1) are composed of a first material and a second material, and the trends of the elastic moduli of the first material and the second material changing with temperature are different.

4. The precision temperature-controlled deployable structure based on 4D printing according to claim 3, wherein: The bi-material arches (1) include: A passive layer composed of the first material; An active layer composed of the second material; The trend of the elastic modulus of the first material changing with temperature is smaller than that of the second material.

5. The precision temperature-controlled deployable structure based on 4D printing according to claim 4, characterized in that: The active layer is attached to the passive layer.

6. The precision temperature-controlled deployable structure based on 4D printing according to claim 4, characterized in that: The first material is Agilus30, and the second material is RGD8525-DM; Alternatively, the first material is thermoplastic polyurethane elastomer rubber, and the second material is polylactic acid.

7. The precision temperature-controlled deployable structure based on 4D printing according to claim 1, characterized in that: The bi-material arches (1) close to the top plate (5) are connected to the top plate (5) through the struts (4).

8. The precision temperature-controlled deployable structure based on 4D printing according to claim 1, characterized in that, There are a plurality of the temperature-controlled deployable units, and adjacent temperature-controlled deployable units are connected through the struts (4).

9. The usage method of the precisely temperature-controlled deployable structure based on 4D printing according to any one of claims 1 to 8, characterized in that: Including the following steps: Step 1: Place the precision temperature-controlled deployable structure based on 4D printing in an environment below the glass transition temperature of the second material, fix the bottom annular support (2) on a plane, and apply an axial load to the top plate (5) to cause the bi-material arches (1) of all layers to undergo snap-through buckling; Step 2: Remove the axial load applied to the top plate (5) to make the bi-material arches (1) of all layers stable in the buckled position; Step 3: Move the precision temperature-controlled deployable structure based on 4D printing to an environment above the glass transition temperature of the second material. The second material undergoes a phase change under environmental thermal stimulation, and all the bi-material arches (1) snap back to the state before compression when reaching the critical deployment temperature.

10. The method for using the precisely temperature-controlled deployable structure based on 4D printing according to claim 9, characterized in that: The environment is an air, vacuum or liquid environment.

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