Environmental perception paper-cut metamaterial design with simplified shape memory effect and reconstruction method thereof

Abstract

The invention discloses a design and reconstruction method of an environmental perception paper-cut metamaterial with a simplified shape memory effect, and particularly relates to the technical field of intelligent response shape memory metamaterials. The invention aims to solve the problems that the existing shape memory material is poor in multi-shape memory ability and is often accompanied by unexpected springback, so that the precision is insufficient, the chemical dependence is strong and the response speed is low. The paper cutting structure comprises a plurality of unit cells, each unit cell comprises two boundary units and a plurality of rotating units, the two boundary units are oppositely arranged, a cavity is formed between the two boundary units, and the rotating units can move inside and outside the cavity between the two boundary units. The two boundary units and the multiple rotating units are connected into an integral structure through the ligament assemblies, the multiple unit cells are sequentially arranged, and the adjacent boundary units between every two adjacent unit cells are fixedly connected.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent response shape memory metamaterials, and in particular to a design of an environment-aware paper-cut metamaterial with a simplified shape memory effect and a reconstruction method thereof. Background Art

[0002] In nature, biomaterials exhibit a wide range of intelligent behaviors. These behaviors are usually triggered and responded to external stimuli, such as the rapid response of Venus flytraps to touch, the opening and closing of pine cones under humidity changes, and the color change of chameleons according to the environment. Such response mechanisms provide inspiration for the development of smart materials, making the design of mechanical metamaterials and shape memory materials gradually develop in the direction of being able to respond to external stimuli. Among these materials, shape memory materials can recover from temporary shapes to permanent shapes under the action of external stimuli (such as temperature, light or humidity), becoming a hot topic of research. However, the performance of existing shape memory materials has obvious limitations: first, most shape memory materials can only remember one or two shapes, which is difficult to meet the needs of multi-shape memory; second, these materials often have undesirable rebound phenomena during the recovery process, resulting in insufficient shape recovery accuracy; in addition, such materials usually rely on the regulation of chemical composition or complex thermomechanical programming to achieve memory function, making the preparation process cumbersome and difficult to control. Therefore, in order to achieve richer intelligent response characteristics, it is of great significance to develop a metamaterial with a simplified shape memory effect that has a simple structure, rapid response, and the ability to be programmed multiple times. Summary of the invention

[0003] In order to solve the problems of existing shape memory materials that lack multi-shape memory ability and are often accompanied by undesirable rebound, resulting in insufficient precision, strong chemical dependence and slow response speed, the present invention proposes a design of an environmentally-aware paper-cut metamaterial with simplified shape memory effect and a reconstruction method thereof. Through clever structural design and strategic combination of component materials, the present invention can achieve multi-shape memory effects and rapid response without relying on chemical regulation, providing insights and guidance for a variety of intelligent applications such as intelligent heat dissipation systems, temperature sensors, and fire alarm systems.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A design of an environmentally-aware paper-cut metamaterial with a simplified shape memory effect includes a plurality of unit cells, wherein the unit cells include two boundary units and a plurality of rotation units. The two boundary units are arranged opposite to each other, a chamber is formed between the two boundary units, and the plurality of rotation units can move inside and outside the chamber between the two boundary units. The two boundary units and the plurality of rotation units are connected into an integral structure through a ligament assembly. The plurality of unit cells are arranged in sequence, and the adjacent boundary units between each two adjacent unit cells are fixedly connected.

[0006] Furthermore, the boundary unit is a frame with an open inner end.

[0007] Further, the outer contours of the plurality of rotating units match the contour of the cavity between the two boundary units.

[0008] Furthermore, the ligament assembly includes a boundary ligament and a rotational ligament. The rotational unit is connected to an adjacent boundary unit via the boundary ligament, and every two adjacent rotational units are connected via a rotational ligament.

[0009] Furthermore, one end of the boundary ligament is connected to the side wall of the open end of the boundary unit, and the other end of the boundary ligament is connected to the adjacent inner corner of the adjacent rotation unit.

[0010] Furthermore, the plurality of rotating units can rotate inside and outside the cavity of the boundary unit by mechanical loading, and the plurality of rotating units can rotate and return to the initial position by external stimulation.

[0011] Furthermore, the boundary unit is made of material A, which is a material sensitive to external stimuli, and the rotation unit is made of material B, which is a material insensitive to external stimuli, and the elastic modulus of material A is greater than the elastic modulus of material B under initial conditions.

[0012] Furthermore, the external stimulus includes one or more of temperature, humidity, light or magnetic field.

[0013] A reconstruction method for an environment-aware kirigami metamaterial design with simplified shape memory effect includes the following processes:

[0014] Under the initial conditions, the rotation of the rotation unit is induced by mechanical loading, resulting in the shape reconstruction of the unit cell. Since the elastic modulus of material A applied to the boundary unit under the initial conditions is higher than that of material B applied to the rotation unit, the boundary unit can provide constraints to maintain the reconstructed geometric shape, thereby realizing the programmable morphology of the unit cell.

[0015] When the external stimulus input changes, the elastic modulus of material A applied to the boundary unit decreases when it reaches a critical value, causing the boundary unit with material A as the component material to soften and reduce its constraint ability. The reconstructed rotation unit will restore the shape before reconstruction to achieve the shape memory effect.

[0016] Furthermore, the mechanical loading includes one or more of stretching, compression or bending.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. Simplified multi-shape memory effect: No complicated chemical composition adjustment is required, and multi-shape programming and switching can be achieved through simple geometric structure design and strategic combination of commercially available materials;

[0019] 2. Composite deformation mode: It can realize a variety of mechanical deformations, including stretching, bending, compression, etc., and can achieve shape recovery in multiple directions;

[0020] 3. Multifunctionality: The structure has the characteristics of environmental change-induced shape recovery and mechanical property switching, and can be applied to flexible robots, adaptive sensors, and self-powered drives. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the stretching process of the paper-cut metamaterial unit cell when the rotating unit in the present invention is a square;

[0022] Figure 2 It is a structural schematic diagram of the compression process of the paper-kirigami metamaterial unit cell when the rotating unit in the present invention is a square;

[0023] Figure 3 It is a structural schematic diagram of the stretching process of the paper-cut metamaterial unit cell when the rotation unit in the present invention is a triangle;

[0024] Figure 4 It is a structural schematic diagram of the compression process of the paper-kirigami metamaterial unit cell when the rotation unit in the present invention is a triangle;

[0025] Figure 5 This is a structural diagram of the bending process of the paper-cut metamaterial unit cell when the rotating unit in the present invention is an irregular shape. Figure 1 ;

[0026] Figure 6 This is a structural diagram of the bending process of the paper-cut metamaterial unit cell when the rotating unit in the present invention is an irregular shape. Figure 2 ;

[0027] Figure 7 is a schematic diagram of shape change of multiple shape memory in the present invention;

[0028] Figure 8 is a graph showing the relationship between the elastic modulus of the component materials and temperature;

[0029] Fig. 9 It is a diagram showing an embodiment of the programmable morphology and shape memory effect of an axially deformable single-cell kirigami structure;

[0030] Fig.10 It is a diagram showing an embodiment of the programmable morphology and shape memory effect of a bending and deforming unit-cell kirigami structure;

[0031] Fig.11It is a diagram showing an embodiment of the programmable morphology and shape memory effect of a multicellular paper-cut structure;

[0032] Fig.12 It is a schematic diagram of an environment-aware shrinkable multi-cell paper-cut structure in a planar configuration;

[0033] Fig.13 It is a schematic diagram of an environment-aware expandable multi-cell paper-cut structure in a plane configuration;

[0034] Fig.14 It is a schematic diagram of another environment-aware shrinkable multi-cell paper-cut structure in a planar configuration;

[0035] Fig.15 It is another schematic diagram of an environmentally-aware expandable multi-cell paper-cut structure in a planar configuration;

[0036] Fig.16 It is a schematic diagram of a three-dimensional axially expanded (contracted) multi-cellular paper-cut structure in a cubic configuration;

[0037] Fig.17 It is a schematic diagram of a three-dimensional axially expanded (contracted) multi-cellular paper-cut structure configured with a cylinder;

[0038] Fig.18 It is a schematic diagram of a three-dimensional non-axially expanded (contracted) multi-cellular paper-cut structure in a cubic configuration;

[0039] Fig.19 It is a schematic diagram of a three-dimensional non-axially expanded (contracted) multi-cellular paper-cut structure configured with a cylinder;

[0040] Fig. 20 This is an embodiment diagram of the temperature rise alarm process of a temperature alarm device based on a rotating square paper-cut structure unit cell;

[0041] Fig.21 This is an embodiment diagram of the early warning process of a temperature alarm based on a rotating square paper-cut structure unit cell approaching a fire source;

[0042] Fig. 22 This is an embodiment diagram of the throwing process of a thrower based on a rotating triangle paper-cut structure unit cell;

[0043] Fig.23 This is a diagram showing an example of a robot grasping process based on a multicellular paper-kirigami structure;

[0044] Fig.24 This is a diagram showing an implementation example of the release process of a robot based on a polyhedral paper-cut structure. DETAILED DESCRIPTION

[0045] Specific implementation method 1: Combination Figures 1 to 24To describe this embodiment, an environment-aware paper-cut metamaterial design with a simplified shape memory effect described in this embodiment includes a plurality of unit cells, wherein the unit cell includes two boundary units 1 and a plurality of rotation units 2, the two boundary units 1 are arranged opposite to each other, a chamber is formed between the two boundary units 1, the plurality of rotation units 2 can move inside and outside the chamber between the two boundary units 1, the two boundary units 1 and the plurality of rotation units 2 are connected into an integral structure by a ligament assembly, the plurality of unit cells are arranged in sequence, and the adjacent boundary units 1 between every two adjacent unit cells are fixedly connected.

[0046] The core of the present invention lies in the structural design and the strategic matching of component materials. In terms of structural design, the present invention proposes a variety of paper-cut structures, which are composed of single or multiple dual / multi-stable geometric modules and can present rich geometric shapes in plane and spatial forms. In terms of the strategic combination of component materials, the structure uses two commercially available materials with different environmentally dependent elastic moduli to achieve switching of different shapes through environmental changes, and performs stability transitions in multiple mechanical modes (such as stretching, bending, compression, etc.), realizing multifunctional applications such as shape recovery, stiffness switching and rapid response.

[0047] Specifically, the kirigami structure is composed of a boundary unit 1 that provides boundary constraints and a modular rotation unit 2 with rotation characteristics. It should be noted that the boundary unit 1 and the rotation unit 2 are only exemplary, and their geometric shapes can be freely selected. Figures 1 to 6 As shown, the boundary unit 1 may include various geometric shapes such as rectangles and triangles, and the rotation unit 2 may include various geometric shapes such as squares, triangles, irregular figures, etc. Through symmetrical or asymmetrical design, various deformation modes such as stretching, compression, bending, etc. can be realized in dual / multi-stable switching.

[0048] Another necessary condition for realizing the programmable morphology of paper-cut structures is the strategic combination of component materials. The present invention uses two materials with different environment-dependent elastic moduli to construct paper-cut structures, and these two materials are material A and material B. The selection of the two materials is not specific, but must meet the following requirements: the two materials have different sensitivities to the same stimulus (such as temperature, humidity, light, etc.). Specifically, material A should be sensitive to stimuli, and changes in stimulus input can cause significant changes in the elastic modulus of the material (the elastic modulus decreases rapidly when the environmental change reaches a critical value). On the contrary, material B should be a material that is insensitive to stimuli, and the elastic modulus of the material will not change significantly when the stimulus input changes. Moreover, under initial conditions, the elastic modulus of material A should be greater than the elastic modulus of material B. Of the two materials, material A is applied to boundary unit 1 and material B is applied to rotation unit 2.

[0049] Its mechanism of action is that under initial conditions, mechanical loading can induce the rotation of the rotation unit 2, resulting in shape reconstruction. Since the elastic modulus of material A applied to the boundary unit 1 is higher than that of material B applied to the rotation unit 2 under initial conditions, the boundary unit 1 can provide sufficiently strong constraints to maintain the reconstructed geometric shape, thereby realizing a programmable morphology. When the external stimulus input changes, the elastic modulus of material A decreases rapidly when it reaches a critical value, causing the boundary unit 1 with material A as a component material to gradually soften and the constraint ability to gradually decrease, and the reconstructed rotation unit 2 restores the shape before reconstruction to achieve a shape memory effect.

[0050] Its multi-shape memory is reflected in that, compared with the traditional shape memory material, the multi-stable structure of the orderly arrangement of unit cells in the present invention has rich shape and geometric changes. Figure 7 As shown, examples of polyhedral forms of paper-cut structures and some of their programmable forms are provided. Based on the above mechanism, these programmable forms can return to their initial shapes through external stimulation, thereby achieving shape memory effect.

[0051] Its simplified shape memory effect is reflected in: Compared with traditional shape memory materials, the present invention achieves shape memory effect through structural design and strategic combination of commercially available materials, and avoids complex chemical composition regulation and multi-step thermomechanical programming. Specifically, in terms of chemical composition regulation, traditional shape memory materials usually rely on changes in the chemical composition of the material to achieve response, and often require the introduction of special chemical components into the material or a complex synthesis process to adjust the memory performance. In contrast, the present invention only uses two commercially available materials with different environment-dependent elastic moduli, without changing the chemical properties of the material, and can achieve shape recovery through the physical properties of the material. This method avoids the cumbersome process of chemical regulation, making the preparation of the material simpler and suitable for large-scale production. In terms of multi-step mechanical programming, traditional shape memory materials usually need to rely on complex programming processes, including multiple steps of heating, cooling and external force, to achieve a single or limited shape memory effect. The paper-cut structure of the present invention adopts a dual-material combination with different sensitivity responses to environmental changes, and can form a stable temporary shape by adjusting the structural morphology by external force without external stimulation, without the need for multiple heating and external force reprogramming. After the introduction of external stimulation, the balance of the temporary shape is destroyed due to the change in the elastic modulus of the component materials in the structure, triggering the automatic recovery of the shape, thus realizing the shape memory effect, providing an efficient and low-cost method for designing shape memory metamaterials.

[0052] Specific implementation method 2: Combination Figures 1 to 19 To explain this embodiment, the boundary unit 1 described in this embodiment is a frame body with an open inner end. The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0053] Specific implementation method three: Combination Figures 1 to 19 To explain this embodiment, the outer contours of the plurality of rotating units 2 in this embodiment match the contours of the chamber between the two boundary units 1. The undisclosed technical features in this embodiment are the same as those in the second embodiment.

[0054] Specific implementation method four: Combination Figures 1 to 19 This embodiment is described. The ligament assembly in this embodiment includes a boundary ligament 3 and a rotation ligament 4. The rotation unit 2 is connected to the adjacent boundary unit 1 via the boundary ligament 3, and each adjacent two rotation units 2 are connected via the rotation ligament 4. The undisclosed technical features in this embodiment are the same as those in the third embodiment.

[0055] Specific implementation method five: Combination Figures 1 to 19 To illustrate this embodiment, one end of the boundary ligament 3 in this embodiment is connected to the side wall of the open end of the boundary unit 1, and the other end of the boundary ligament 3 is connected to the adjacent inner corner of the adjacent rotation unit 2. The undisclosed technical features in this embodiment are the same as those in the fourth embodiment.

[0056] Specific implementation method six: Combination Figures 1 to 19 To explain this embodiment, the plurality of rotating units 2 can rotate inside and outside the cavity of the boundary unit 1 by mechanical loading, and the plurality of rotating units 2 can rotate back to the initial position by external stimulation. The undisclosed technical features of this embodiment are the same as those of the first embodiment.

[0057] Specific implementation method seven: Combination Figures 1 to 19 This embodiment is described. The boundary unit 1 in this embodiment is made of material A, which is a material sensitive to external stimuli. The rotation unit 2 is made of material B, which is a material insensitive to external stimuli. The elastic modulus of material A under initial conditions is greater than the elastic modulus of material B. The undisclosed technical features in this embodiment are the same as those in the sixth embodiment.

[0058] Specific implementation method eight: Combination Figures 1 to 19 To explain this embodiment, the external stimulus described in this embodiment includes one or more of temperature, humidity, light or magnetic field. The undisclosed technical features in this embodiment are the same as those in the seventh embodiment.

[0059] Specific implementation method nine: Combination Figures 1 to 19 This embodiment describes a reconstruction method of an environment-aware paper-cut metamaterial design with a simplified shape memory effect, which includes the following process:

[0060] Under the initial conditions, the rotation of the rotation unit 2 is induced by mechanical loading, resulting in the shape reconstruction of the unit cell; since the elastic modulus of the material A applied to the boundary unit 1 is higher than that of the material B applied to the rotation unit 2 under the initial conditions, the boundary unit 1 can provide a sufficiently strong constraint to maintain the reconstructed geometric shape, thereby realizing the programmable morphology of the unit cell;

[0061] When the external stimulus input changes, the elastic modulus of material A applied to the boundary unit 1 decreases when reaching a critical value, causing the boundary unit 1 with material A as a component material to become soft and the constraint ability to decrease. The reconstructed rotation unit 2 will restore the shape before reconstruction to achieve the shape memory effect.

[0062] Specific implementation method ten: Combination Figures 1 to 19 This embodiment is described, and the mechanical loading in this embodiment includes one or more of stretching, compression or bending. The undisclosed technical features in this embodiment are the same as those in the ninth embodiment.

[0063] In all the embodiments provided below, temperature stimulation is used as environmental input. Material A is a temperature-sensitive material, and commercially available TOP 31B (black) is selected. Material B is a temperature-insensitive material TPU 90A (white). The elastic modulus curves of the two materials changing with temperature are shown in FIG. Figure 8 As shown. Material A is applied to the boundary unit 1, and material B is applied to the rotation unit 2. It should be noted that the temperature stimulation and material selection here are exemplary. As long as the design principles of the present invention are followed, the paper-cut structure of the present invention can be applied to other stimuli (such as humidity, light, magnetic field, etc.) using different material combinations to achieve shape memory effect.

[0064] Example 1: Multistability and shape memory effect of single-cell kirigami structure

[0065] This embodiment takes the rotating square unit as an example to demonstrate the multi-stability and shape memory effect of the single-cell kirigami structure. Fig. 9 and Fig.10 As shown, two embodiments of the unit cell design are given. The difference between the two unit cells is that different deformation modes are achieved by controlling the number of rotational ligaments (by controlling whether there are gaps between adjacent squares). It specifically includes two aspects:

[0066] (1) Programmable morphology at low temperatures

[0067] In a low temperature environment (such as room temperature), the shape of the unit cell kirigami structure is programmed by gradually applying external force. Specifically, the rotation of the rotation unit 2 is realized by the external force to form a temporary shape, and the boundary unit 1 composed of material A provides high rigidity support to maintain the temporary shape to complete the shape reconstruction. For example, Fig. 9The stretched shape of the unit cell under the action of axial tensile external force. Fig.10 The bending deformation of the unit cell under the action of external bending force.

[0068] (2) Shape memory effect under temperature response

[0069] When the external temperature rises to a critical value (the critical temperature that causes a significant change in the elastic modulus of material A), the elastic modulus of material A decreases significantly, and the rigid support of boundary unit 1 weakens, triggering the morphological recovery of the paper-cut structure. It specifically includes two stages: the first stage: before the temperature reaches the glass transition temperature of material A, the elastic modulus of material A gradually decreases, the boundary constraint force gradually decreases, and the internal structure begins to transition from a temporary form to an initial form. The second stage: when the temperature reaches the glass transition temperature, the elastic modulus of material A decreases rapidly, the boundary unit 1 softens rapidly, and the entire structure returns to its original form, completing the restoration of the memory shape.

[0070] Example 2: Multi-stability and shape memory effect of multi-cell paper-cut structure

[0071] Based on the first embodiment, the second embodiment shows a multi-cell paper-cut structure formed by orderly arranging and combining multiple single-cell paper-cut units. Compared with the single-cell paper-cut structure, the multi-cell paper-cut structure has richer programmable forms, such as Fig.11 As shown in the figure, it also includes two processes, namely, programmable morphology at room temperature and shape recovery under temperature response. However, unlike single cells, multi-cell combinations provide higher deformation freedom and multi-stable properties, which can achieve local or overall morphological reconstruction, such as loading processes ① to ⑤, and temperature-related step-by-step deformation recovery (processes ⑥ and ⑦), providing richer and more interesting shape changes and functional applications.

[0072] In addition to the above-mentioned multi-cell paper-cut structures, the present invention also provides some cases that can be used for the design of expandable (contractible) structures, such as Figures 12 to 19 As shown. Among them, Figures 12 to 15 Two multi-cell structures with two-dimensional expansion (contraction) configurations are shown. Through the orderly arrangement and combination of multiple unit cells, a wide range of expansion and contraction functions are achieved on the plane. Such structures can be stretched or compressed to the desired state by external forces at room temperature, and are suitable for application scenarios that require flat coverage or protection. At the same time, under temperature changes, the structure can automatically expand or contract, thereby acting as a dynamic sunshade, providing temperature-dependent shading or light transmission adjustments. Fig.16 and Fig.17Examples of three-dimensionally expanded polyhedral paper-cut structures are provided, including cubic and cylindrical polyhedral paper-cut structures. The cubic polyhedral structure has directional symmetry and can expand or contract in three dimensions under temperature changes. It is suitable for structures that need to be stretched or contracted in all directions, such as retractable storage devices or space filling materials. The cylindrical polyhedral structure has the characteristics of axial expansion and is suitable for applications such as flexible conveying pipelines and telescopic support columns. For non-axial expansion, Fig.18 and Fig.19 The multicellular structure composed of rotating triangular units is demonstrated. This structure can achieve more complex asymmetric morphological changes by rotating the geometric configuration of the triangular units, which is suitable for non-axially adjustable structural requirements. Under temperature stimulation, the triangular units in the structure can expand or contract the structure through rotational deformation, thus having highly programmable complex morphological changes.

[0073] Example 3: Temperature alarm based on rotating square paper-cut structure unit cell

[0074] In this embodiment, a temperature alarm based on a single-cell paper-cut structure is designed. Fig. 20 and Fig.21 As shown. Its working principle is that, first, the unit cell is reshaped under low temperature conditions and placed in a circuit connected to the alarm in a disconnected form. When the temperature rises (fire occurs or is close to the fire source) to the glass transition temperature of material A in the paper-cut structure, the shape memory effect of the structure is triggered, and the structure restores its initial shape to connect the circuit, thereby activating the alarm. In addition, it should be noted that the key to whether the structure triggers the shape memory effect and deforms is whether material A reaches the glass transition temperature. Therefore, the selection of material A with different glass transition temperatures can achieve the customization of the alarm temperature and even the design of a graded alarm device.

[0075] Compared with traditional electronic alarms based on complex highly integrated circuits, paper-cut temperature alarms that focus on mechanical structures have the following advantages: (1) Low power consumption: Traditional electronic alarms require real-time power supply to detect changes in ambient temperature, while paper-cut temperature alarms rely on the direct response of materials to temperature and do not require continuous power support. (2) Simple structure: The design of paper-cut temperature alarms is relatively simple, with low manufacturing costs and suitable for large-scale production. In contrast, the integrated circuit design and manufacturing process of electronic alarms are complex, involving a variety of electronic components (such as sensors, control chips, batteries, etc.), requiring higher manufacturing precision and more complex processes. (3) High reliability and strong anti-interference: The paper-cut structure is based on the principle of mechanical response and is not affected by electromagnetic interference or signal interference. It is particularly suitable for environments that resist electromagnetic radiation or other electrical interference. For example, in heavy industry, steel mills or environments with high electromagnetic interference, electronic alarms may be misreported or fail due to external signal interference, while paper-cut alarms can maintain a stable working state due to mechanical response and have high reliability. (4) Wide operating temperature range: The paper-cut structure alarm sets the response threshold through the glass transition temperature of the material to adapt to working requirements under extreme high temperature conditions, while traditional electronic alarms may damage circuits or components due to high temperature environments. Paper-cut alarms can adapt to various temperature conditions more flexibly in terms of material selection and structural design. Especially in high-temperature fires, their responses are more reliable and less prone to damage. (5) Graded alarm: Paper-cut alarms can achieve multi-level alarms at different temperatures by combining materials with different glass transition temperatures. In fire warning, the paper-cut structure can be gradually expanded according to the temperature to achieve phased and graded alarms, while traditional electronic alarms can often only set a single alarm temperature threshold or find it difficult to achieve complex graded alarm functions.

[0076] Example 4: Throwing device based on rotating triangle paper-cut structure unit cell

[0077] This embodiment shows a throwing device based on a rotating triangle paper-cut structure, such as Fig. 22 As shown. Its working process includes three main steps: (1) Accumulation of elastic potential energy (standby state): Under low temperature conditions, the paper-cut unit cell is reshaped. Due to the high rigidity constraint of the boundary unit 1, the energy stored in the shape reconstruction process is mechanically locked, thereby realizing elastic energy storage. (2) Trigger release: After meeting the preset trigger condition (reaching the specified temperature), the boundary unit 1 composed of material A softens, the mechanical lock is released, the paper-cut structure is rapidly unfolded, and the stored elastic potential energy is instantly released, ejecting the object to hit the target. (3) Energy storage again: After the throwing is completed, the paper-cut structure can be restored to its initial state, and energy storage can be realized again through external force loading and preparing for a second throw, so as to realize multiple services.

[0078] Similarly, mechanical response-based throwers also have many advantages. Specifically, they include: (1) Energy efficiency and stable properties: using the elastic potential energy of the paper-cut structure to throw objects, no complex electric drive is required, and it is suitable for outdoor or power-free environments. (2) Precise control: through the temperature trigger mechanism, the throwing time can be precisely controlled to meet the needs of emergency and unmanned operation. (3) Multiple reuse: the paper-cut structure can be restored to its original shape through temperature stimulation and allowed to be reconstructed again to store energy, achieving multiple repeated throwing and improving the efficiency of the device.

[0079] Example 5: Robotic arm based on polyhedral paper-cut structure

[0080] This embodiment demonstrates a flexible manipulator device based on a multicellular paper-cut structure. Fig.23 and Fig.24 As shown. Each "finger" in the manipulator is composed of a combination of unit cells with axial deformation and bending deformation. At room temperature, through shape reconstruction, the manipulator can have a variety of programmable forms, so that the manipulator remains stable between different angles and curvatures, so as to flexibly adjust the opening and closing state of its "fingers" to adapt to objects of different shapes and sizes. When the manipulator needs to grasp or release an object, the shape memory effect of the multi-cell paper-cut structure can be used to achieve automatic morphological transformation through temperature triggering. Specifically, during the operation of the grasping manipulator, when the ambient temperature rises or reaches the glass transition temperature of material A through artificial heating, the elastic modulus of material A is significantly reduced, the boundary constraints of each unit cell in the "fingers" of the manipulator are weakened, and the unit cells with compressed and unbent reconstructed forms are released, prompting each unit cell unit to rotate so that the "fingers" are stretched and bent and gradually closed, completing the grasping action. During the operation of the releasing manipulator, environmental changes cause the unit cells with stretched and bent reconstructed forms to be released, prompting each unit cell unit to rotate so that the "fingers" are restored from the closed state to the initial state, completing the release action. In addition, as a type of multicellular paper-cut structure, the robot also has all the advantages of the above-mentioned mechanical response, which will not be elaborated here.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A design of an environment-aware paper-cut metamaterial with simplified shape memory effect, characterized by: The invention comprises a plurality of unit cells, wherein the unit cells comprise two boundary units (1) and a plurality of rotation units (2); the two boundary units (1) are arranged opposite to each other, a chamber is formed between the two boundary units (1), the plurality of rotation units (2) can move inside and outside the chamber between the two boundary units (1), the two boundary units (1) and the plurality of rotation units (2) are connected to form an integral structure via a ligament assembly, the plurality of unit cells are arranged in sequence, and the adjacent boundary units (1) between each two adjacent unit cells are fixedly connected.

2. According to claim 1, the environment-aware paper-cut metamaterial design with simplified shape memory effect is characterized by: The boundary unit (1) is a frame body with an open inner end.

3. According to claim 2, the environment-aware paper-cut metamaterial design with simplified shape memory effect is characterized by: The outer profiles of the plurality of rotating units (2) match the cavity profile between the two boundary units (1).

4. According to claim 3, the environment-aware paper-cut metamaterial design with simplified shape memory effect is characterized by: The ligament assembly comprises a boundary ligament (3) and a rotational ligament (4); the rotational unit (2) is connected to an adjacent boundary unit (1) via the boundary ligament (3), and every two adjacent rotational units (2) are connected via the rotational ligament (4).

5. According to claim 4, the environment-aware paper-cut metamaterial design with simplified shape memory effect is characterized by: One end of the boundary ligament (3) is connected to the side wall of the open end of the boundary unit (1), and the other end of the boundary ligament (3) is connected to the adjacent inner corner of the adjacent rotation unit (2).

6. According to claim 1, the environment-aware paper-cut metamaterial design with simplified shape memory effect is characterized by: The plurality of rotating units (2) can rotate inside and outside the cavity of the boundary unit (1) through mechanical loading, and the plurality of rotating units (2) can rotate and return to the initial position through external stimulation.

7. The environmentally-aware paper-cut metamaterial design with simplified shape memory effect according to claim 6, characterized in that: The boundary unit (1) is made of material A, which is a material sensitive to external stimuli; the rotation unit (2) is made of material B, which is a material insensitive to external stimuli; and the elastic modulus of material A is greater than the elastic modulus of material B under initial conditions.

8. According to claim 7, the environment-aware paper-cut metamaterial design with simplified shape memory effect is characterized by: The external stimulus includes one or more of temperature, humidity, light or magnetic field.

9. A reconstruction method for an environment-aware paper-cut metamaterial design with simplified shape memory effect according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: Under the initial condition, the rotation of the rotation unit (2) is induced by mechanical loading, thereby causing the shape reconstruction of the unit cell; since the elastic modulus of the material A applied to the boundary unit (1) under the initial condition is higher than that of the material B applied to the rotation unit (2), the boundary unit (1) can provide constraints to maintain the reconstructed geometric shape, thereby realizing the programmable morphology of the unit cell; When the external stimulus input changes, the elastic modulus of the material A applied to the boundary unit (1) decreases when reaching a critical value, so that the boundary unit (1) with material A as a component material becomes soft and the constraint ability decreases. The reconstructed rotation unit (2) will restore the shape before reconstruction to achieve a shape memory effect.

10. The reconstruction method of the environment-aware paper-cut metamaterial design with simplified shape memory effect according to claim 9, characterized in that: The mechanical loading includes one or more of tension, compression or bending.

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