Device and method for constructing three-dimensional structure of inert homogeneous plastic film

Abstract

The invention provides a device and a method for constructing a three-dimensional structure of an inert homogeneous plastic film. The device comprises a bottom plate and a plate body arranged on the bottom plate, the plane where the plate body is located is perpendicular to the plane where the bottom plate is located. The side wall, facing the bottom plate, of the plate body comprises a transition curved surface. An interval space for the inert homogeneous plastic film to pass through is formed between the transition curved surface and the bottom plate; the transition curved surface is configured in a way that the inert homogeneous plastic film is clung to the transition curved surface and passes through the transition curved surface by applying pulling force, so that the inert homogeneous plastic film is extruded by different degrees from the transition curved surface along the two sides of the thickness direction of the inert homogeneous plastic film; the inert homogeneous plastic film is subjected to asymmetric plastic strain along two sides of the thickness direction of the inert homogeneous plastic film in the stretching process, so that the inert homogeneous plastic film is curled. Therefore, the problem that a preparation process is complicated due to the fact that a heterogeneous layer or a response layer is inevitably introduced when an existing device is used for constructing a three-dimensional structure is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible electronic devices, and more specifically, to a device and method for realizing the construction of a three-dimensional structure of an inert homogeneous plastic film. Background Art

[0002] Compared with planar flexible electronic devices, three-dimensional flexible electronic devices can better match complex-shaped biological objects and have higher design freedom and space utilization, thus realizing many applications that are difficult to achieve with two-dimensional electronic devices, including high-efficiency energy collection devices, spatial resolution photodetectors, multifunctional electronic skin, robotics, etc. However, the current processing and preparation technology of flexible electronics is mainly limited by planar technologies such as spin coating, lithography, and deposition, and it is difficult to directly prepare circuits or sensor elements on three-dimensional structures. Therefore, the current preparation of three-dimensional flexible electronics bypasses the direct manufacturing method and transforms two-dimensional electronic devices manufactured by traditional planar technology into three-dimensional electronic devices through shape transformation strategies.

[0003] The important substrate materials of current flexible thin film devices, such as polyethylene terephthalate (PET), polyimide (PI) and polytetrafluoroethylene (PTFE), are all inert homogeneous plastic films. Realizing the shape transformation of these thin film materials will provide new ideas for producing three-dimensional flexible devices with various structures and functions. The shape transformation methods currently used to prepare three-dimensional electronic devices are mainly based on the mechanical principles of heterogeneous materials or structures, such as residual stress, capillary force, responsive driving force, etc. A representative one is the literature "Sheng Xu, Zheng Yan, John A. Rogers, et al. Assembly of micro / nanomaterials into complex, three-dimensional architectures by compressive buckling [J]. Science 2015, 347: 154-159", which proposed that the corresponding three-dimensional structure is constructed by selectively bonding the two-dimensional film pattern to the pre-stretched elastomer substrate and then releasing the pre-strain. The corresponding stretching table structure for preparing the pre-stretched elastomer to achieve stress release is as follows: Figure 1 As shown in . The above-mentioned traditional devices and methods for realizing the shape transformation of membrane materials from two-dimensional to three-dimensional are limited to heterogeneous or stimuli-responsive materials. And when preparing three-dimensional flexible electronic devices by the above-mentioned traditional shape transformation methods, it is inevitable to introduce heterogeneous layers or responsive layers, which complicates the preparation process. Summary of the invention

[0004] In view of the above problems, the present invention provides a device for constructing a three-dimensional structure of an inert homogeneous plastic film to solve the problem that the existing devices will inevitably introduce heterogeneous layers or response layers when constructing three-dimensional structures, thereby complicating the preparation process.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a device for realizing the construction of a three-dimensional structure of an inert homogeneous plastic film, comprising:

[0007] A bottom plate and a plate body arranged on the bottom plate; the plane where the plate body is located is perpendicular to the plane where the bottom plate is located;

[0008] The side wall of the plate body facing the bottom plate includes a transition curved surface;

[0009] The transition curved surface and the bottom plate include a spacing space for the inert homogeneous plastic film to pass through;

[0010] The transition curved surface is configured to apply a tensile force to slide the inert homogeneous plastic film close to the transition curved surface, so that the inert homogeneous plastic film is squeezed to different degrees from the transition curved surface on both sides along its own thickness direction, so that during the stretching process, the inert homogeneous plastic film undergoes asymmetric plastic strain on both sides along its own thickness direction, thereby achieving curling of the inert homogeneous plastic film.

[0011] A preferred solution is that the device also includes a pulley assembly located on one side of the plate body; the pulley assembly includes two door frames arranged in sequence along the first direction and first fixed pulleys respectively arranged on the cross beams of the door frames; the transition curved surface of the plate body and the cross beams of the door frames both extend along the second direction; in the plane where the base plate is located, the first direction and the second direction are perpendicular to each other.

[0012] A preferred solution is that the plate body is fixed to the base plate by a clamping structure; the device also includes a tension mechanism connected to one end of the inert homogeneous plastic film and a weight connected to the other end of the inert homogeneous plastic film, and the weight and the first fixed pulley are located on the same side of the plate body.

[0013] A preferred solution is that the device also includes two first pulley mechanisms respectively arranged on both sides of the base plate along the first direction and a second pulley mechanism located on the side of one of the first pulley mechanisms away from the base plate; the first pulley mechanism includes a cross bar and a second fixed pulley arranged on the cross bar; the second pulley mechanism includes a cross axis with the same setting direction as the cross bar and a third fixed pulley arranged on the cross axis; the transition curved surface of the plate body extends along the first direction, and the cross bar extends along the second direction; in the plane where the base plate is located, the first direction and the second direction are perpendicular to each other.

[0014] A preferred solution is that the plate body is fixed to the base plate by a clamping structure; the device also includes a tension mechanism connected to one end of the inert homogeneous plastic film and a weight connected to the other end of the inert homogeneous plastic film, and the tension mechanism and the second pulley mechanism are located on the same side of the plate body.

[0015] The present invention also provides a method for constructing a three-dimensional structure of an inert homogeneous plastic film according to the above-mentioned device, comprising the following steps: determining a pre-deformed region of the inert homogeneous plastic film, and cutting a two-dimensional precursor pattern in the pre-deformed region of the inert homogeneous plastic film;

[0016] Pass one end of the inert homogeneous plastic film through the space between the transition curved surface and the bottom plate so that the pre-deformed area of ​​the inert homogeneous plastic film fits the transition curved surface;

[0017] By applying a tensile force to one end of the inert homogeneous plastic film, the pre-deformed region of the inert homogeneous plastic film is drawn along the transition surface, so that the pre-deformed region of the inert homogeneous plastic film is squeezed to different degrees from the transition surface on both sides along the thickness direction of the film, so that asymmetric plastic strain occurs on both sides of the inert homogeneous plastic film along the thickness direction of the film during the stretching process;

[0018] When the pre-deformed area has completely passed under the transition curved surface of the plate body, the pulling is stopped and the pre-deformed area is cut off from the inert homogeneous plastic film to achieve curling of the pre-deformed area.

[0019] The preferred solution is to provide a tension mechanism and a weight, connect one end of the inert homogeneous plastic film to the tension mechanism, and pass the other end through the space between the transition curved surface and the bottom plate and connect to the weight.

[0020] A preferred solution is that the device also includes a pulley assembly located on one side of the plate body; the pulley assembly includes two door frames arranged in sequence along the first direction and first fixed pulleys respectively arranged on the cross beams of the door frames; the transition curved surface of the plate body and the cross beams of the door frames both extend along the second direction; in the plane where the base plate is located, the first direction and the second direction are perpendicular to each other; the other end of the inert homogeneous plastic film is connected to the weight through the first fixed pulley; the pulling mechanism is opened so that the pre-deformed area of ​​the inert homogeneous plastic film passes through the transition curved surface at the lower edge of the plate body, and after passing through, the pre-deformed area of ​​the inert homogeneous plastic film is cut off to achieve the shape transformation of the pre-deformed area from two-dimensional to three-dimensional.

[0021] A preferred solution is that the device also includes two first pulley mechanisms respectively arranged on both sides of the base plate along the first direction and a second pulley mechanism located on the side away from the base plate of one of the first pulley mechanisms; the first pulley mechanism includes a cross bar and a second fixed pulley arranged on the cross bar; the second pulley mechanism includes a transverse axis in the same direction as the cross bar and a third fixed pulley arranged on the transverse axis; the transition curved surface of the plate body extends along the first direction, and the cross bar extends along the second direction; in the plane where the base plate is located, the first direction and the second direction are perpendicular to each other; one end of the inert homogeneous plastic film is connected to the tension mechanism through two second fixed pulleys located on the same side of the base plate, and the other end is connected to the weight through the second fixed pulley on the other side of the base plate; the tension mechanism is opened, so that the pre-deformation area of ​​the inert homogeneous plastic film passes through the transition curved surface at the lower edge of the plate body, and after passing through, the pre-deformation area of ​​the inert homogeneous plastic film is cut off to realize the shape transformation of the pre-deformation area from two-dimensional to three-dimensional.

[0022] The preferred solution is that when the angle between the membrane that has crossed the transition surface and the membrane that has not crossed the transition surface in the membrane plane direction is equal to 0 degrees, the direction of the maximum principal plastic strain is the same as the direction of the membrane's long axis; when the angle between the membrane that has crossed the transition surface and the membrane that has not crossed the transition surface in the membrane plane direction is not equal to 0 degrees, the direction of the maximum principal plastic strain is different from the direction of the membrane's long axis.

[0023] The beneficial effects of the present invention are:

[0024] The present invention applies a tensile force to draw a plastic homogeneous film close to the transition surface. Since the film is squeezed to different degrees from the surface in the thickness direction during the process, asymmetric plastic strain occurs on both sides of the film, thereby achieving curling. In the process, parameters that have an important influence on the curling effect, such as tension, film thickness, radius of curvature of the surface, angle α and deflection angle β, can be precisely controlled by an asymmetric stretching device. In addition, the transition surface in the method acts on the side of the film with smaller plastic strain. The shape transformation method of the asymmetric stretching of the present invention, in addition to having broad application prospects in the preparation of three-dimensional flexible electronics, can also be combined with various functional materials such as shape memory materials and stimulus responsive materials, so as to be used in the development of four-dimensional intelligent response systems and multi-dimensional, multi-scale functional materials. The device provided by the present invention is simple to operate, low in cost, and good in mechanical durability. And the device is small in overall size, light in weight, easy to carry, and can be operated in different occasions. Compared with traditional shape transformation devices and methods that are only applicable to heterogeneous or stimulus responsive films, the device of the present invention has a wider applicability. The process of preparing three-dimensional structures by the device of the present invention is based on asymmetric plastic strain, so the prepared three-dimensional structure can be maintained independently for a long time, without the need for external conditions such as stimulation to maintain its own shape like the three-dimensional structures obtained by traditional devices and methods, thereby simplifying the three-dimensional structure construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0026] Figure 1 It is a structural schematic diagram of an existing stretching table for preparing a pre-stretched elastomer to achieve stress release.

[0027] Figure 2A It is a top view of the first specific embodiment of the present invention.

[0028] Figure 2B It is a front view of a first specific embodiment of the present invention.

[0029] Figure 2C It is a schematic diagram of the cooperation between the first specific embodiment of the present invention and the film.

[0030] Figure 3A It is a top view of a second specific embodiment of the present invention.

[0031] Figure 3B It is a front view of a second specific embodiment of the present invention.

[0032] Figure 3C It is a schematic diagram of the cooperation between the second specific embodiment of the present invention and the film.

[0033] Figure 4 It is a schematic diagram of obtaining corresponding three-dimensional structures after different planar structures are subjected to asymmetric stretching deformation by the device of the present invention.

[0034] Figure 5A It is a schematic diagram of the angle α between the film that has scratched the curved surface and the film that has not scratched the curved surface in the normal direction of the film plane of the present invention.

[0035] Figure 5B It is a schematic diagram of the deflection angle β in the film plane direction of the film that has been scratched on the curved surface and the film that has not been scratched on the curved surface of the present invention.

[0036] Figure 6 It is a side view of the plate body of the present invention. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0038] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0039] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0040] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0041] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0042] As important substrate materials for current flexible thin film devices, polyethylene terephthalate (PET), polyimide (PI) and polytetrafluoroethylene (PTFE) are all inert homogeneous plastic films. Realizing the shape transformation of these thin film materials will provide new ideas for the production of three-dimensional flexible devices with various structures and functions.

[0043] However, existing devices and methods are inevitably limited to heterogeneous or responsive materials, and cannot achieve the three-dimensional structure construction of the above-mentioned inert homogeneous plastic film materials. For example, a method that is currently widely used is to selectively bond a two-dimensional film pattern to a pre-stretched elastomer substrate and then release the pre-strain to achieve the three-dimensional structure construction of a two-dimensional film. This method mainly relies on the elastic recovery force of the elastomer and the strain mismatch between the sample film, and inevitably requires the introduction of an elastic layer in the constructed three-dimensional structure, and cannot achieve the three-dimensional construction of a single inert homogeneous plastic film material.

[0044] In order to realize the three-dimensional structure construction of inert homogeneous plastic film materials and simplify the three-dimensional structure construction process. The present invention provides a device for realizing the three-dimensional structure construction of an inert homogeneous plastic film, which can directly realize the transformation of the two-dimensional to three-dimensional shape of the inert homogeneous plastic film, and can directly realize the preparation of three-dimensional flexible electronic devices without introducing a heterogeneous layer or a response layer. The operation is simple and the process is highly controllable. The device of the present invention can be applied to all two-dimensional films including inert homogeneous plastic films. Combined with Figures 1 to 5BAs shown, the device for realizing the construction of the three-dimensional structure of the inert homogeneous plastic film specifically includes: a bottom plate 11 and a plate body 12 arranged on the bottom plate 11; the plate body 12 can specifically be a steel plate. The plane where the plate body 12 is located is perpendicular to the plane where the bottom plate 11 is located, that is, the plate surface of the plate body 12 is perpendicular to the plate surface of the bottom plate 11. The side wall of the plate body 12 facing the bottom plate 11 includes a transition curved surface 121; the transition curved surface 121 and the bottom plate 11 include a spacing space for the inert homogeneous plastic film 3 to pass through. It should be noted that the two ends of the transition curved surface 121 are connected to the two plate surfaces of the plate body 11 and the curvature of the curved surface can be determined according to actual needs. The extension direction of the transition curved surface 121 is the same as the extension direction of the side wall where it is located. The transition curved surface 121 can be the entire side wall surface of the plate body 12 facing the bottom plate 11, or it can be a part of the side wall. The transition curved surface 121 is configured to apply a tensile force to slide the inert homogeneous plastic film 3 close to the transition curved surface 121, so that the inert homogeneous plastic film 3 is squeezed to different degrees from the transition curved surface 121 on both sides along its own thickness direction, so that asymmetric plastic strain occurs on both sides along the thickness direction of the film itself during the stretching process of the film, thereby achieving the curling of the inert homogeneous plastic film 3.

[0045] The present invention is based on an asymmetric stretching strategy to achieve fine control of the plastic strain of an inert homogeneous film, thereby achieving the design and construction of a three-dimensional structure. Specifically, it is achieved by applying a tensile force to make the plastic homogeneous film close to the transition surface 121 of the lower edge of the steel plate and pass through it. Since the curved surface will produce asymmetric extrusion on the film along the thickness direction during this process, asymmetric tensile strain will occur on the inside and outside of the film. After the external force is removed, the plastic strain remains in the film, thereby achieving deformation of the plastic film. Since the plastic deformation that occurs in this process can be stably preserved, the resulting three-dimensional structure can exist for a long time without the need for an external heterogeneous layer to maintain it. Based on the above description, the device of the present invention can be called an asymmetric stretching device.

[0046] Further, when the angle between the film that crosses the transition curved surface 121 and the film that does not cross the transition curved surface 121 in the film plane direction is equal to 0 degrees, the maximum principal plastic strain direction is the same as the film long axis direction. When the angle between the film that crosses the curved surface and the film that does not cross the curved surface in the film plane direction is not equal to 0 degrees, the maximum principal plastic strain direction is different from the film long axis direction.

[0047] In the process of constructing three-dimensional structures, the main parameters that affect the shape transformation effect of homogeneous films are tension, film thickness, radius of curvature of the curved surface, angle α (the angle between the film that crosses the curved surface and the film that does not cross the curved surface in the normal direction of the film plane) and deflection angle β (the angle between the film that crosses the curved surface and the film that does not cross the curved surface in the direction of the film plane). When β = 0, the direction of the maximum principal plastic strain is the same as the direction of the long axis of the film, so it will curl along the long axis of the film to obtain a cylinder. This is achieved by a β = 0 asymmetric stretching device. When β ≠ 0, the direction of the maximum principal plastic strain is different from the direction of the long axis of the film, so a spiral is obtained because the curling direction is inconsistent with the long axis direction of the film. This is achieved by a β ≠ ​​0 asymmetric stretching device. By designing the stretched two-dimensional precursor pattern and stretching parameters, a variety of complex three-dimensional structures can be controlled and designed.

[0048] The present invention realizes the construction of a three-dimensional structure of an inert homogeneous film based on asymmetric stretching. Specifically, a tensile force is applied to make the plastic homogeneous film slide closely against a transition surface 121. Since the transition surface 121 will produce asymmetric extrusion on the film along the thickness direction during the process, asymmetric tensile strain will occur on the inner and outer sides of the film, thereby achieving curling. The steel plate can support the pressure of the sample film on the curved surface to prevent the curved surface from deforming during the stretching process. The steel plate clamping structure can keep the steel plate in a vertical state at all times during the stretching process. At the same time, the use of the clamping structure makes it possible to control the curvature of the curved surface that the sample film slides through by replacing the steel plate with a lower edge transition surface 121 of different curvatures.

[0049] About the specific structure of the asymmetric stretching device. The asymmetric stretching device includes two different structures: β=0 asymmetric stretching device and β≠0 asymmetric stretching device. By changing the position of the clamping structure and the fixed pulley, important parameters such as α and β can be precisely controlled. The important parameters in the asymmetric stretching process can be precisely controlled. By designing a two-dimensional pattern and controlling the important parameters of the asymmetric stretching process (tension, film thickness, radius of curvature of the curved surface, angle α and deflection angle β), the three-dimensional structure of the plastic homogeneous film can be precisely controlled and designed. All components of the asymmetric stretching device are made of stainless steel. The ranges of angle α and deflection angle β are: 0≤α<180°; 0≤β<180°. The ranges of tension, film thickness, and radius of curvature of the curved surface are interrelated and related to the material modulus. Taking PET film as an example, when the thickness is 50 microns, the radius of curvature of the curved surface is 0.25mm, and the width is 4mm, the maximum tension is 8N. If any of the film thickness, surface curvature radius, and material modulus is changed, the range of tension values ​​will change.

[0050] Combination Figure 2A-2CAs shown, the bottom plate 11 of the β=0 asymmetric stretching device includes a first clamping structure 15 for clamping and fixing the plate body 12. The first clamping structure 15 makes the steel plate in a vertical state, ensuring that the transition curved surface 121 bulges downward. The device also includes a pulley assembly located on one side of the plate surface of the plate body 12; the pulley assembly includes two door frames 13 arranged in sequence along the first direction and first fixed pulleys 14 respectively arranged on the cross beams 19 of the door frames 13, and the door frames 13 span the top of the bottom plate 11; the extension direction of the transition curved surface 121 of the plate body 12 is the same as the extension direction of the cross beam 19 of the door frame 13 and both extend along the second direction; in the plane where the bottom plate is located, the first direction and the second direction are perpendicular. The first direction is the X direction, the second direction is the Y direction, and the third direction is the Z direction, and the Z direction is perpendicular to both the X direction and the Y direction, and the plate body 12 is arranged along the Z direction. Furthermore, the plate body 12 is fixed to the bottom plate 11 by a first clamping structure 15, and two first fixed pulleys 14 are located on the same side of the plate body 12; the device also includes a tension mechanism 17 connected to one end of the inert homogeneous plastic film 3 and a weight 18 connected to the other end of the inert homogeneous plastic film 3, and the weight 18 and the first fixed pulley 14 are located on the same side of the plate body 12. When the β=0 asymmetric stretching device is in use, the sample film passes through the curved surface of the lower edge of the steel plate, one end is connected to the tensile machine, and the other end is connected to the weight 18 through the two first fixed pulleys 14. The tension mechanism 17 is turned on, so that the pre-deformed area of ​​the film passes through the curved surface of the lower edge of the steel plate. After passing through, the pre-deformed area of ​​the sample film is cut off immediately to achieve the shape transformation of the area from two-dimensional to three-dimensional. In this process, the curvature of the sample film passing over the curved surface can be adjusted by replacing steel plates with edges of different curvatures; the pulling force can be adjusted by changing the mass of the weight 18; and the angle α can be adjusted by changing the distance between the two first fixed pulleys 14 through horizontal movement.

[0051] Combination Figure 3A-3CAs shown, the bottom plate 11 of the β≠0 asymmetric stretching device includes a second clamping structure 26 for clamping and fixing the plate body 12. The second clamping structure 26 ensures that the steel plate is in a vertical state with the curved edge facing downward. The device also includes two first pulley mechanisms 23 respectively arranged on two opposite sides of the bottom plate 11 along the first direction and a second pulley mechanism 24 located on the side away from the bottom plate 11 of one of the first pulley mechanisms 23, the first pulley mechanism 23 includes a cross bar 27 and a second fixed pulley 25 arranged on the cross bar 27; the second pulley mechanism 24 includes a cross shaft 29 arranged in the same direction as the cross bar 27 and a third fixed pulley 28 arranged on the cross shaft 29; the extension direction of the transition curved surface 121 of the plate body 12 is perpendicular to the extension direction of the cross bar 27, that is, the transition curved surface 121 of the plate body 12 extends along the first direction, and the cross bar 27 extends along the second direction; in the plane where the bottom plate 11 is located, the first direction and the second direction are perpendicular. The first direction is the X direction, the second direction is the Y direction, and the third direction is the Z direction, and the Z direction is perpendicular to both the X direction and the Y direction, and the plate body 12 is arranged along the Z direction. The plate body 12 is fixed to the bottom plate 11 by a second clamping structure 26. The device also includes a tension mechanism 17 connected to one end of the inert homogeneous plastic film 3 and a weight 18 connected to the other end of the inert homogeneous plastic film 3, and the tension mechanism 17 and the second pulley mechanism 24 are located on the same side of the plate body 12. The tension mechanism 17 can be specifically a tension machine. When the β≠0 asymmetric stretching device is in use, the sample film is close to the curved surface of the lower edge of the steel plate, one end is connected to the tension mechanism 17 through two second fixed pulleys 25 on the same side of the bottom plate 11, and the other end is connected to the weight 18 through the second fixed pulley 25 located on the other side of the bottom plate 11. Turn on the tension machine so that the pre-deformed area of ​​the sample film passes through the curved surface of the lower edge of the steel plate. After the sample film is slid across, the pre-deformed area of ​​the sample film is cut off immediately to achieve the shape transformation of the area from two-dimensional to three-dimensional. In this process, the curvature of the sample film slid across the curved surface can be adjusted by replacing steel plates with edges of different curvatures; the tension can be adjusted by changing the mass of the weight 18; and the β angle can be adjusted by changing the spacing between the two first pulley mechanisms 23 by horizontal movement. The operating parameters of the present invention can be precisely controlled, so that the prepared three-dimensional structure is highly controllable.

[0052] The present invention also provides a method for constructing a three-dimensional structure of an inert homogeneous plastic film according to the device as described above, comprising the following steps: determining a pre-deformed region of the inert homogeneous plastic film 3, and cutting a two-dimensional precursor pattern in the pre-deformed region of the inert homogeneous plastic film 3; passing one end of the inert homogeneous plastic film 3 through the space between the transition curved surface 121 and the bottom plate 11 so that the pre-deformed region of the inert homogeneous plastic film 3 is in contact with the transition curved surface 121; applying a tensile force to one end of the inert homogeneous plastic film 3 to deform the inert homogeneous plastic film 3; The pre-deformed area of ​​the plate body 12 is passed along the transition curved surface 121, so that the pre-deformed area of ​​the inert homogeneous plastic film 3 is squeezed to different degrees on both sides along the thickness direction of the pre-deformed area of ​​the inert homogeneous plastic film 3, so that asymmetric plastic strain occurs on both sides along the thickness direction of the pre-deformed area of ​​the inert homogeneous plastic film 3 during the stretching of the film by tension; when the pre-deformed area is completely passed under the transition curved surface 121 of the plate body 12, the pulling is stopped and the pre-deformed area is cut off from the inert homogeneous plastic film 3 to achieve curling of the pre-deformed area.

[0053] Furthermore, a tension mechanism 17 and a weight 18 are provided, one end of the inert homogeneous plastic film 3 is connected to the tension mechanism 17 , and the other end passes through the interval space between the transition curved surface 121 and the bottom plate 11 and is connected to the weight 18 .

[0054] When using the β=0 asymmetric stretching device, the device also includes a pulley assembly located on one side of the plate surface of the plate body 12; the pulley assembly includes two door frames 13 arranged in sequence along the first direction and first fixed pulleys 14 respectively arranged on the crossbeams 19 of the door frames 13; the extension direction of the transition curved surface 121 of the plate body 12 is the same as the extension direction of the crossbeam 19 of the door frame 13, and both extend along the second direction; in the plane where the bottom plate 11 is located, the first direction and the second direction are perpendicular. The other end of the inert homogeneous plastic film 3 is connected to the weight 18 through the first fixed pulley 14; the tension mechanism 17 is opened, so that the pre-deformed area of ​​the inert homogeneous plastic film 3 passes through the transition curved surface 121 at the lower edge of the plate body 12, and after passing through, the pre-deformed area of ​​the inert homogeneous plastic film 3 is cut off to realize the shape transformation of the pre-deformed area from two-dimensional to three-dimensional. The curvature of the film sliding across the curved surface is regulated by replacing the plate 12 with a transition curved surface 121 of different curvatures; the pulling force is regulated by changing the mass of the weight 18; and the angle α is regulated by adjusting the distance between the two door frames 13 by horizontal movement.

[0055] When the β≠0 asymmetric stretching device is used, the device further comprises two first pulley mechanisms 23 respectively arranged on two opposite sides of the bottom plate 11 along the first direction and a second pulley mechanism 24 located on the side away from the bottom plate 11 of one of the first pulley mechanisms 23, the first pulley mechanism 23 comprises a cross bar 27 and a second fixed pulley 25 arranged on the cross bar 27, the second pulley mechanism 24 comprises a transverse axis 29 arranged in the same direction as the cross bar 27 and a third fixed pulley 28 arranged on the transverse axis 29; the extension direction of the transition curved surface 121 of the plate body 12 is perpendicular to the extension direction of the cross bar 27; that is, the transition curved surface 121 of the plate body 12 extends along the first direction, and the cross bar 27 extends along the second direction; in the plane where the bottom plate 11 is located, the first direction and the second direction are perpendicular. One end of the inert homogeneous plastic film 3 is connected to the tension mechanism 17 through the two second fixed pulleys 25 located on the same side of the bottom plate 11, and the other end is connected to the weight 18 through the second fixed pulley 25 on the other side of the bottom plate 11. Open the tension mechanism 17, so that the pre-deformed area of ​​the inert homogeneous plastic film 3 passes through the transition curved surface 121 at the lower edge of the plate body 12. After passing through, the pre-deformed area of ​​the inert homogeneous plastic film 3 is cut off to achieve the shape transformation of the pre-deformed area from two-dimensional to three-dimensional. In this process, the curvature of the sample film passing through the curved surface can be controlled by replacing steel plates with edges of different curvatures; the tension can be controlled by changing the mass of the weight 18; and the β angle can be controlled by changing the spacing between the two second fixed pulleys 25 on both sides of the plate body 12 by horizontal movement. Specifically, when the inert homogeneous plastic film is a PET film, the radius of curvature of the transition curved surface 121 is usually required to be less than 2.5 mm; the weight mass / film width is usually required to be less than 200 g·mm -1 .

[0056] More specifically, the specific operation method for realizing the construction of the three-dimensional structure of the inert mean film is as follows:

[0057] A PET film (thickness: 50 μm) was cut into strips of 4 mm × 200 mm using a film cutter; a two-dimensional precursor pattern was designed and cut in the pre-deformed area (4 mm × 50 mm) of the film using the film cutter; one end of the film was connected to the tensile machine through a fixture; the other end of the film passed under a steel plate with a curvature radius of 0.25 mm at the lower edge and was connected to a weight through a fixed pulley (the weight mass is adjustable, and the weight mass / film width is usually selected to be <200 g·mm -1 ; The curvature radius of the lower edge of the steel plate can be designed and adjusted, usually the curvature radius needs to be <2.5mm); Turn on the tensile machine and set the speed to 300mm·min -1 ; When the pre-deformed area passes under the steel plate, immediately turn off the tensile machine and stop pulling; cut the pre-deformed area from the film and leave it for half an hour until the shape deformation stabilizes, and the three-dimensional structure can be formed and maintained. Figure 4 As shown, Figure 4The diagram in the figure is a schematic diagram of a three-dimensional structure constructed by an asymmetric stretching strategy. It includes a total of ten groups of corresponding structures, with the left side of the same group of structures showing a two-dimensional pattern and the right side showing the corresponding three-dimensional structure after deformation.

[0058] Specifically a: the two-dimensional pattern is stretched by a β=0 asymmetric stretching device, α=0, β=0 are controlled, and the weight mass is 600g.

[0059] b: The two-dimensional pattern is stretched by a β=0 asymmetric stretching device, α=0, β=0 are controlled, and the weight mass is 600 g.

[0060] c: The two-dimensional pattern is stretched by a β=0 asymmetric stretching device, α=0, β=0 are controlled, and the weight mass is 600 g.

[0061] d: The two-dimensional pattern is stretched by a β=0 asymmetric stretching device, and α=0 and β=0 are controlled. When in the single-line zone, the front side is loaded, and the weight mass is 600g; when entering the double-line zone, the film is turned over so that the other side contacts the lower edge of the steel plate, the reverse side is loaded, and the weight mass is changed to 1000g; when entering the single-line zone again, the film is turned over again, the front side is loaded, and the weight mass is taken to 600g again.

[0062] e: The two-dimensional pattern is stretched by an asymmetric stretching device with β≠0, and α is controlled to be 0. β is maintained at 45° by adjusting the position of the second fixed pulley, and the weight is 1000 g.

[0063] f: Stretch the two-dimensional pattern through the β=0 asymmetric stretching device, control α=0, β=0. The weight is 600g, pull the double-line area, remove the weight after entering the single-line area, and take the weight of 600g when entering the double-line area again.

[0064] g: Stretch the two-dimensional pattern through the asymmetric stretching device with β≠0, and control α=0, β=0. Take the weight of 700g, pull 1 / 4 of the length of the pre-deformed area, change the weight to 600g and pull it again 1 / 4 of the length, change the weight to 500g again and pull it 1 / 4 of the length of the pre-deformed area, and then change the weight to 400g and pull it 1 / 4 of the length of the pre-deformed area.

[0065] h: Stretch the two-dimensional pattern through the asymmetric stretching device with β≠0, and control α = 0. Adjust the position of the second fixed pulley to keep β = 45°, and take the weight mass of 600g to pull 2 / 3 of the length, and change the weight mass to 300g to pull 1 / 3 of the length.

[0066] i: Stretch the two-dimensional pattern through the asymmetric stretching device with β≠0, and control α = 0. Adjust the position of the second fixed pulley to keep β = 45°, and take the weight mass of 600g to pull 2 / 3 of the length, and change the weight mass to 300g to pull 1 / 3 of the length.

[0067] j: Stretch the two-dimensional pattern through the asymmetric stretching device with β≠0, and control α=0. Adjust the position of the second fixed pulley to keep β=45°, take the weight mass of 600g to pull the narrow area, remove the weight after entering the wide area, and when entering the narrow area again, turn the film over so that the other side contacts the lower edge of the steel plate, load the reverse side, and take the weight mass of 600g.

[0068] In summary, the present invention applies a tensile force to draw the plastic homogeneous film close to the transition surface. Since the film is squeezed to different degrees from the surface in the thickness direction during the process, asymmetric plastic strain occurs on both sides of the film, thereby achieving curling. In this process, parameters that have an important influence on the curling effect, such as tension, film thickness, radius of curvature of the surface, angle α and deflection angle β, can be precisely controlled by an asymmetric stretching device. In addition, the transition surface in this method acts on the side of the film where the plastic strain is smaller. The shape transformation method of the asymmetric stretching of the present invention, in addition to having broad application prospects in the preparation of three-dimensional flexible electronics, can also be combined with various functional materials such as shape memory materials and stimulus responsive materials, so as to be used in the development of four-dimensional intelligent response systems and multi-dimensional, multi-scale functional materials. The device provided by the present invention is simple to operate, low in cost, and good in mechanical durability. And the device is small in overall size, light in weight, easy to carry, and can be operated in different occasions. Compared with traditional shape transformation devices and methods that are only applicable to heterogeneous or stimulus responsive films, the device of the present invention has a wider applicability. The process of preparing three-dimensional structures by the device of the present invention is based on asymmetric plastic strain, so the prepared three-dimensional structure can be maintained independently for a long time, without the need for external conditions such as stimulation to maintain its own shape like the three-dimensional structures obtained by traditional devices and methods, thereby simplifying the three-dimensional structure construction process.

[0069] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A device for constructing a three-dimensional structure of an inert homogeneous plastic film, characterized in that: include: A bottom plate and a plate body arranged on the bottom plate; the plane where the plate body is located is perpendicular to the plane where the bottom plate is located; The side wall of the plate body facing the bottom plate includes a transition curved surface; The transition curved surface and the bottom plate include a spacing space for the inert homogeneous plastic film to pass through; The transition curved surface is configured to apply a tensile force to slide the inert homogeneous plastic film close to the transition curved surface, so that the inert homogeneous plastic film is squeezed to different degrees from the transition curved surface on both sides along its own thickness direction, so that during the stretching process, the inert homogeneous plastic film undergoes asymmetric plastic strain on both sides along its own thickness direction, thereby achieving curling of the inert homogeneous plastic film.

2. The device for constructing a three-dimensional structure of an inert homogeneous plastic film according to claim 1, characterized in that: The device also includes a pulley assembly located on one side of the plate body; the pulley assembly includes two door frames arranged in sequence along a first direction and first fixed pulleys respectively arranged on the cross beams of the door frames; the transition curved surface of the plate body and the cross beams of the door frames both extend along a second direction; in the plane where the base plate is located, the first direction and the second direction are perpendicular to each other.

3. The device for constructing a three-dimensional structure of an inert homogeneous plastic film according to claim 2, characterized in that: The plate body is fixed on the bottom plate by a clamping structure; the device also includes a tension mechanism connected to one end of the inert homogeneous plastic film and a weight connected to the other end of the inert homogeneous plastic film, and the weight and the first fixed pulley are located on the same side of the plate body.

4. The device for constructing a three-dimensional structure of an inert homogeneous plastic film according to claim 1, characterized in that: The device also includes two first pulley mechanisms respectively arranged on both sides of the base plate along the first direction and a second pulley mechanism located on the side of one of the first pulley mechanisms away from the base plate; the first pulley mechanism includes a cross bar and a second fixed pulley arranged on the cross bar; the second pulley mechanism includes a cross axis in the same direction as the cross bar and a third fixed pulley arranged on the cross axis; the transition curved surface of the plate body extends along the first direction, and the cross bar extends along the second direction; in the plane where the base plate is located, the first direction and the second direction are perpendicular to each other.

5. The device for constructing a three-dimensional structure of an inert homogeneous plastic film according to claim 4, characterized in that: The plate body is fixed on the bottom plate by a clamping structure; the device also includes a tension mechanism connected to one end of the inert homogeneous plastic film and a weight connected to the other end of the inert homogeneous plastic film, and the tension mechanism and the second pulley mechanism are located on the same side of the plate body.

6. A method for constructing a three-dimensional structure of an inert homogeneous plastic film using the device according to any one of claims 1 to 5, characterized in that: The following steps are involved: determining a pre-deformed region of the inert homogeneous plastic film, and cutting a two-dimensional precursor pattern in the pre-deformed region of the inert homogeneous plastic film; Pass one end of the inert homogeneous plastic film through the space between the transition curved surface and the bottom plate so that the pre-deformed area of ​​the inert homogeneous plastic film fits the transition curved surface; By applying a tensile force to one end of the inert homogeneous plastic film, the pre-deformed region of the inert homogeneous plastic film is drawn along the transition surface, so that the pre-deformed region of the inert homogeneous plastic film is squeezed to different degrees from the transition surface on both sides along the thickness direction of the film, so that asymmetric plastic strain occurs on both sides of the inert homogeneous plastic film along the thickness direction of the film during the stretching process; When the pre-deformed area has completely passed under the transition curved surface of the plate body, the pulling is stopped and the pre-deformed area is cut off from the inert homogeneous plastic film to achieve curling of the pre-deformed area.

7. The method according to claim 6, characterized in that A tension mechanism and a weight are provided, one end of the inert homogeneous plastic film is connected to the tension mechanism, and the other end passes through the interval space between the transition curved surface and the bottom plate and is connected to the weight.

8. The method according to claim 7, characterized in that The device also includes a pulley assembly located on one side of the plate body; the pulley assembly includes two door frames arranged in sequence along the first direction and first fixed pulleys respectively arranged on the cross beams of the door frames; the transition curved surface of the plate body and the cross beams of the door frames both extend along the second direction; in the plane where the bottom plate is located, the first direction and the second direction are perpendicular to each other; the other end of the inert homogeneous plastic film is connected to the weight through the first fixed pulley; the tension mechanism is opened so that the pre-deformed area of ​​the inert homogeneous plastic film passes through the transition curved surface at the lower edge of the plate body, and after passing through, the pre-deformed area of ​​the inert homogeneous plastic film is cut off to realize the shape transformation of the pre-deformed area from two-dimensional to three-dimensional.

9. The method according to claim 7, characterized in that: The device also includes two first pulley mechanisms respectively arranged on both sides of the base plate along the first direction and a second pulley mechanism located on the side away from the base plate of one of the first pulley mechanisms; the first pulley mechanism includes a cross bar and a second fixed pulley arranged on the cross bar; the second pulley mechanism includes a cross axis in the same direction as the cross bar and a third fixed pulley arranged on the cross axis; the transition curved surface of the plate body extends along the first direction, and the cross bar extends along the second direction; in the plane where the base plate is located, the first direction and the second direction are perpendicular to each other; one end of the inert homogeneous plastic film is connected to the tension mechanism through the two second fixed pulleys located on the same side of the base plate, and the other end is connected to the weight through the second fixed pulley on the other side of the base plate; the tension mechanism is opened, so that the pre-deformation area of ​​the inert homogeneous plastic film passes through the transition curved surface at the lower edge of the plate body, and after passing through, the pre-deformation area of ​​the inert homogeneous plastic film is cut off to realize the shape transformation of the pre-deformation area from two-dimensional to three-dimensional.

10. The method according to claim 6, characterized in that When the angle between the membrane that has passed through the transition surface and the membrane that has not passed through the transition surface in the membrane plane direction is equal to 0 degrees, the direction of the maximum principal plastic strain is the same as the direction of the long axis of the membrane; when the angle between the membrane that has passed through the transition surface and the membrane that has not passed through the transition surface in the membrane plane direction is not equal to 0 degrees, the direction of the maximum principal plastic strain is different from the direction of the long axis of the membrane.

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