Visual material based on cephalopodocephalus biological skin discoloration mechanism and preparation method thereof

Abstract

The invention relates to a model based on a head-foot line biological skin discoloration mechanism, which comprises a plurality of model units arranged in an array mode, and each model unit comprises a refraction layer and a pigment information layer; the refraction layer plays a refraction role, and the pigment information layer carries pigment information; the pigment information layer comprises an annular pigment layer, a round hole is formed in the center of the pigment information layer, colors are distributed on the annular pigment layer in a block mode, and a central white cylinder is further arranged at the round hole aligned to the center of the pigment information layer; the top view of an annular pigment layer of the pigment information layer is a circular ring, the circular ring is provided with three pure color blocks which are arranged at intervals, and a mixed transition color block is formed between every two adjacent pure color blocks; the refraction layer is in the shape of a transparent semi-long sphere, the refraction layer covers the whole pigment information layer in the refraction layer and close to the bottom, and the bottom face of the central white cylinder is flush with the bottom of the refraction layer. Based on the model, a full-color 3D printing technology is combined to prepare the cephalopoda biological skin discoloration simulation visual material, and the discoloration efficiency and the impression experience of the visual material are improved.

Description

[0001] Case Analysis

[0002] This invention is a divisional application of the parent application filed on December 24, 2024, with application number 202411909757.2 and titled "A visual illusion material based on the skin color-changing mechanism of cephalopods and its preparation method". Technical Field

[0003] This invention belongs to the field of new materials technology, and in particular to a visual illusion material based on the skin color-changing mechanism of cephalopods and its preparation method. Background Technology

[0004] Color can be categorized into structural color, pigment color, and combined color. These two types of color have different mechanisms of production, but both can make objects appear in a specific color. Structural color is produced by a pure physical structure without any pigment components. Pigment color is based on the absorption or dispersion of light by pigments. Combined color is a biological form resulting from the combination of pigment and structural color. Among these, structural color possesses many advantages that pigment color lacks. Compared to pigment color, which is easily affected by the environment, structural color is usually composed of a simple physical structure; as long as its physical structure is not destroyed, its color will not diminish. Structural color not only has high brightness and high saturation but also often exhibits an iridescent effect. Structural color does not rely on toxic pigments or other chemical substances, making it more environmentally friendly.

[0005] Currently, the preparation methods for single-structure color materials can be categorized according to the optical principles of structural color: ① Multilayer thin-film interference methods, including rainbow films, titanium alloy anodic oxide films, color-changing pearlescent powders, and electroplated iridescent materials. ② Grating diffraction methods, including laser direct writing, photolithography, and CNC machining. ③ Scattering methods, including Cu2O spherical Mie scattering structural coloring. ④ Polarized light methods, including dichroic glass and polarized displays. ⑤ Photonic crystal methods, including photonic crystal structural color fibers, photonic crystal structural color fabrics, photonic crystal pigments, and 3D printing for patterned photonic crystals. ⑥ Using natural biological materials to bond structural colors. To achieve precise color effects in the preparation of the aforementioned single-structure color materials, precise control of the material's microstructure is required. This necessitates not only high-precision operation but also extremely stable environmental conditions. Continuous optimization during the preparation process is needed to achieve high color consistency and repeatability. This requires not only highly precise equipment but also a high level of professional knowledge and practical experience from the designers or operators. These factors limit the effective preparation and widespread application of structural color dynamic visual illusion materials, and according to existing technologies, it is difficult to achieve color simulation and color control for specific purposes using currently readily available visual illusion materials.

[0006] Bionic color design, developed on the basis of bionics, mainly studies the superior color functions and forms of biological systems in nature to mimic color perception and control color information feedback, selectively applying these natural principles to artificial color design. In their paper, "Research on Design Innovation Methods of Learning from Nature - Exploring Digital Biological Design Paths," Lan Cuiqin, He Shuang, and others discovered that leopard chameleons change color by actively adjusting the guanine nanocrystal lattice within the iris cells of the epidermis and dermis. Based on this inspiration, researchers in the field can combine a bottom color information layer with an upper transparent crystal layer (which acts as a refractive element), and by adjusting the crystal structure, can obtain dynamic color changes under the influence of light refraction in different crystal structures.

[0007] The skin color-changing effect of cephalopods has a wonderful visual effect. With people's continuous pursuit of quality of life, simulated materials based on the skin color-changing effect of cephalopods are increasingly loved and noticed in mobile terminals, automobile production, dynamic billboards, interactive art, clothing manufacturing and other fields. At the same time, with the development of voxel 3D printing technology, it has provided the possibility of constructing complex three-dimensional structures, which has promoted the further research and application of optical illusion materials. However, how to establish and optimize parameters to obtain a model with simulated skin color-changing effect of cephalopods is still the first technical problem to be solved. For example, the team of Beijing Institute of Fashion Technology previously developed an illusion material containing a crystal layer and a pigment information layer. The pigment information layer is divided into four quadrants by a cross, with two color blocks for each color (containing two color blocks - yellow and purple, located in the diagonal quadrants respectively). However, this distribution setting has certain shortcomings in effect, specifically: (1) the color-changing performance is weak, and the specific color-changing performance achieved is only the alternation of two colors. (2) the color block boundaries are obvious, and when the viewing angle changes laterally, there will be obvious color breaks and visual segmentation. (3) The observation angle coverage is limited. Specifically, it means that only at a specific observation angle and range can a relatively complete color be observed. When the observation angle exceeds the effective observation range (when the angle is close to the top surface and the boundary of the color), the complete color cannot be observed (the broken color blocks of the two colors will be seen at the same time), resulting in a large visual gap.

[0008] To effectively solve the above-mentioned technical problems, this invention further designs and optimizes the model structure by abstracting and refining the dermal cell structure and color-changing principle of cephalopods, thereby expanding the observable range and improving the color-changing performance and visual experience of the simulated cephalopod skin visual illusion material. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a visual illusion material based on the color-changing mechanism of cephalopod skin and its preparation method. By building a model based on the color-changing mechanism of cephalopod skin and optimizing the model's structural parameters, a model with the best simulation effect of cephalopod skin color-changing is obtained. Combined with Stratasys full-color 3D printing technology, a cephalopod skin simulation material is prepared, realizing the simulation of the dynamic color of cephalopod skin from a macroscopic perspective.

[0011] (II) Technical Solution

[0012] In a first aspect, the present invention provides a model based on the skin color change mechanism of cephalopods, comprising: several model units arranged in an array, each model unit including a refractive layer and a pigment information layer; the refractive layer refracts incident light, and the pigment information layer carries pigment information;

[0013] The pigment information layer includes a ring-shaped pigment layer with a central hole. Colors are distributed in blocks on the ring-shaped pigment layer. A central white cylinder is also provided at the central hole aligned with the center of the pigment information layer. The central white cylinder is located below the ring-shaped pigment layer and has a gap between it and the ring-shaped pigment layer, or the central white cylinder is located in the central hole of the ring-shaped pigment layer. The top view of the ring-shaped pigment layer of the pigment information layer is a ring, and the ring has three mutually spaced solid color blocks, with a mixed transition color block formed between two adjacent solid color blocks.

[0014] The refractive layer is a continuous transparent medium, shaped like a hemispherical shape with a circular cross-section. The refractive layer completely covers the pigment information layer inside the refractive layer, near its bottom, with the bottom surface of the central white cylinder flush with the bottom of the refractive layer. Preferably, the hemispherical shape is half the size of a long sphere, which is a rotational ellipsoid formed by rotating around the major axis of an ellipse. The major axis of the ellipse is twice the height of the refractive layer, and the minor axis is the diameter of the base circle.

[0015] According to a preferred embodiment of the present invention, in the top view of the annular pigment layer, the inner radius of the ring is r, the outer radius of the ring is 2.9r-2.95r, and the radius of the central white cylinder is equal to the inner radius of the ring, which is r; the bottom radius of the refractive layer is 3r-3.2r, the height of the refractive layer is 6.35r-6.5r, and the height of the central white cylinder is 0.4-0.6r; wherein, r = 1 to 1.2 mm.

[0016] According to a preferred embodiment of the present invention, the annular pigment layer of the pigment information layer is a planar ring, which is divided into 6 blocks. The first, third, and fifth blocks along the circumferential direction are respectively given three basic colors, and the second, fourth, and sixth blocks are respectively given three gradient transition colors, wherein the transition color is a gradient transition color between two adjacent basic colors. The thickness of the planar ring is 0.4r-0.6r. A central white cylinder is provided below the circular hole of the planar ring. The bottom of the central white cylinder is flush with the bottom of the refractive layer, and there is a distance of 0.25r-0.32r between the top of the central white cylinder and the bottom of the planar ring.

[0017] According to a preferred embodiment of the present invention, the annular pigment layer is an open stepped ring structure composed of three congruent fan rings with an arc of 150-180 degrees connected together and adjacent fan rings overlapping end to end. There is a height difference of one fan ring thickness between the uppermost fan ring and the lowermost fan ring. Each fan ring has an equal thickness of 0.9r-1.1r.

[0018] Each sector ring is composed of pigment particles of different sizes. The pigment particles are short cylindrical rods perpendicular to the bottom surface of the refractive layer. The radius of the pigment particles near the circular hole is smaller than that of the pigment particles near the edge of the annular pigment layer. The radius of the pigment particles near the center line of each sector ring is larger, while the radius of the pigment particles gradually decreases as they develop towards both sides of the center line. Two kinds of mixed pigment particles are randomly mixed at the overlapping part of two sector rings, while the rest of the part consists of pure pigment particles.

[0019] The bottom surfaces of the lower fan ring and the central white cylinder are flush with the bottom surface of the refractive layer, and their pure color pigment particles are dark brown. The pure color pigment particles of the middle fan ring are yellow, and the pure color pigment particles of the upper fan ring are red.

[0020] The lower fan ring overlaps with the middle fan ring, where dark brown and yellow mixed pigment particles are mixed; the middle fan ring overlaps with the upper fan ring, where yellow and red mixed pigment particles are mixed; and the upper fan ring overlaps with the lower fan ring, where dark brown and red mixed pigment particles are mixed.

[0021] According to a preferred embodiment of the present invention, the annular pigment layer is an open stepped ring structure composed of six congruent fan rings with an arc of 60 degrees connected together. The adjacent fan rings are arranged layer by layer upwards with a thickness of 1 / 2 fan ring, and there is a height difference of 2 fan ring thickness between the topmost fan ring and the bottommost fan ring.

[0022] Counting along the circumference, the first, third, and fifth fan rings are each assigned three base colors, while the second, fourth, and sixth fan rings are each assigned three transition colors. The transition colors are a mixture of two adjacent base colors. The bottom surfaces of the first fan ring and the central white cylinder are flush with the bottom surface of the refractive layer. Each fan ring has the same thickness, ranging from 0.4r to 0.6r.

[0023] The aforementioned "open stepped ring structure" refers to a stepped ring structure where the bottommost fan ring and the topmost fan ring are not connected, and the stepped ring structure is a non-closed-loop mode, which is different from the "closed-loop stepped ring structure" described below.

[0024] According to a preferred embodiment of the present invention, the annular pigment layer is a closed-loop stepped ring structure composed of six congruent fan rings with an arc of 60 degrees connected together. The first to fourth fan rings are arranged upwards layer by layer with a thickness of 1 / 2 fan ring, and the fourth to sixth fan rings are arranged downwards layer by layer with a thickness of 1 / 2 fan ring, so that the sixth fan ring is connected to the first fan ring with a thickness of 1 / 2 fan ring higher than the first fan ring. The first, third and fifth fan rings are respectively given three base colors, and the second, fourth and sixth fan rings are respectively given three transition colors, and the transition colors are mixed transition colors of two adjacent base colors. The bottom surfaces of the first fan ring and the central white cylinder are flush with the bottom surface of the refractive layer. The thickness of each fan ring is equal and is 0.4r-0.6r.

[0025] According to a preferred embodiment of the present invention, the annular pigment layer is a three-dimensional ring, which is obtained by processing the height difference between two adjacent fan rings in the closed-loop stepped ring structure into a gentle slope, and then further processing it into a continuous and smooth curved surface; the three-dimensional ring is divided into 6 blocks, the first, third and fifth blocks along the circumferential direction are respectively given three basic colors, and the second, fourth and sixth blocks are respectively given three gradient transition colors, the transition color being a gradient transition color between two adjacent basic colors; the three-dimensional ring forms an angle with the bottom surface of the refractive layer; the lowest position of the bottom surface of the three-dimensional ring and the bottom surface of the central white cylinder are both level with the bottom surface of the refractive layer, and the thickness of the three-dimensional ring is 0.6r-0.75r.

[0026] The model unit reaches a macroscopic size, enabling the simulation of cephalopod skin color-changing effects from a macroscopic perspective. This model unit ensures that the holographic material printed in full color by Stratasys exhibits excellent angle-changing color effects and smooth color rendering. In practical applications, the size of the entire model unit can be scaled from 2.0 mm to several centimeters as needed, while maintaining the thickness of both the pigment information layer and the central white cylinder at ≥0.4 mm. However, when the entire model unit is shrunk to a bottom diameter of less than 1.1 mm, insufficient printing precision may lead to a deterioration in the color-changing effect of the holographic material.

[0027] Secondly, the present invention provides a method for preparing a visual illusion material based on the skin color-changing mechanism of cephalopods, comprising the following steps:

[0028] Modeling was performed according to the model based on the skin color-changing mechanism of cephalopods as described in any of the above embodiments; then, the pigment information layer was printed using colored photosensitive polymer material and the refractive layer was printed using transparent photosensitive polymer material using Stratasys full-color 3D printing technology; after printing, the material was cured under UV light to obtain the visual illusion material based on the skin color-changing mechanism of cephalopods.

[0029] The refractive index of the transparent photosensitive polymer material is preferably 1.5-1.8.

[0030] Thirdly, the present invention provides a visual illusion material based on the skin color-changing mechanism of cephalopods, which is prepared by the above-mentioned preparation method.

[0031] (III) Beneficial Effects

[0032] This invention constructs a model based on the skin color change mechanism of cephalopods and combines it with Stratasys full-color 3D printing technology to prepare a visual illusion material that simulates the skin color change effect of cephalopods, thus realizing the simulation of the skin color change characteristics of cephalopods from a macroscopic perspective.

[0033] The unique convex structure of the refractive layer in the model structure of this invention can effectively amplify the refraction of light reflected from the pigment information layer. The central white cylinder at the bottom center of the pigment information layer is an abstract biomimetic representation of the leukocytes of the dermis in cephalopods, which is significantly different from previous model structure designs. The light reflected by this central white cylinder can be effectively presented in a large area at the top of the crystal after refraction. When viewed from a top-viewing angle, the central color block (white cylinder) at the bottom of the refractive layer can be observed completely without interference from other colors, forming a complete color effect; the central white cylinder can effectively broaden the effective angular range of the viewing angle of the visual illusion material.

[0034] This invention continuously optimizes the annular pigment layer of the pigment information layer, simplifying the structure of the model unit, reducing the technical difficulty of preparing the visual illusion material, and also reducing material costs. This invention uses photosensitive materials and Stratasys 3D inkjet voxel printing technology for printing, thereby enabling the preparation of a novel material that simulates the dynamic colors of cephalopod skin using readily available and inexpensive materials.

[0035] Stratasys 3D inkjet voxel printing technology elevates the two-dimensional "pixel" printing logic to the three-dimensional "voxel" production logic. By reciprocating the nozzle, photosensitive resin is sprayed onto substrate materials such as fabric in inkjet form, and then cured by a UV lamp, achieving rapid and precise one-piece printing production. This technology breaks away from the traditional photosensitive resin immersion printing method, adopting an additive manufacturing logic of inkjet curing. This allows resins with different material properties to be integrally formed in a single printing job. This technology not only ensures production accuracy and efficiency but also maximizes reproduction and color accuracy. Stratasys 3D printers also possess highly transparent resin materials (refractive index between 1.5 and 1.8) and an extremely rich color material library. These characteristics of Stratasys 3D printing technology provide all the necessary elements and possibilities for the preparation of the novel holographic material of this invention, and also provide greater scope for model design and development.

[0036] The model unit size of this invention is approximately (3-3.2) mm × (6.35-6.5) mm, allowing for printing within this range. Precise control of the material's microstructure is not required, resulting in lower operational precision requirements. Compared to current techniques for preparing single-structure color materials, this invention prepares visual illusion materials based on the skin color-changing mechanism of cephalopods without requiring extremely stable environmental conditions. The preparation process is simple, easy to control, and exhibits high repeatability and consistency. This invention enables the further promotion and application of cephalopod skin color-changing simulation materials. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a model unit in the model based on the skin discoloration mechanism of cephalopods constructed in Example 1.

[0038] Figure 2 Based on Figure 1 The model was constructed using a holographic image of material created by Stratasys full-color 3D printing.

[0039] Figure 3 This is a schematic diagram of the structure of a model unit in the model based on the skin discoloration mechanism of cephalopods constructed in Example 2.

[0040] Figure 4 This is a schematic diagram of the structure of a model unit in the model based on the skin discoloration mechanism of cephalopods constructed in Example 3.

[0041] Figure 5 Based on Figure 4 The model was constructed using a holographic image of material created by Stratasys full-color 3D printing.

[0042] Figure 6 This is a schematic diagram of the structure of a model unit in the model based on the skin discoloration mechanism of cephalopods constructed in Example 4.

[0043] Figure 7 Based on Figure 6 The model was constructed using a holographic image of material created by Stratasys full-color 3D printing.

[0044] Figure 8 This is a schematic diagram of the structure of a model unit in the model based on the skin discoloration mechanism of cephalopods constructed in Example 5.

[0045] Figure 9 Based on Figure 8 The model was constructed using a holographic image of material created by Stratasys full-color 3D printing.

[0046] Figure 10 This is the effect of slightly elongating the height of the central white cylinder 22 in the model unit of Example 3. Detailed Implementation

[0047] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Example 1

[0049] This embodiment constructs a model based on the skin color change mechanism of cephalopods, which consists of several model units arranged in an array. Each model unit includes a refractive layer 1 and a pigment information layer 2. The refractive layer 1 refracts the incident light, and the pigment information layer 2 is used to carry pigment information.

[0050] like Figure 1The figures shown are a side view (Figure a), a top view (Figure b), and a perspective view (Figure c) of the model unit of Embodiment 1. The refractive layer 1 is a continuous transparent medium (free of bubbles or voids) used to simulate the transparent cells in chameleon skin, which possess unique refractive and reflective properties. The overall shape of the refractive layer 1 is a semi-spherical structure with a circular cross-section (Prolate Spheroid: when the axis of rotation is the major axis of an ellipse, the resulting ellipsoid is a long sphere), approximating a dome covering and enveloping the entire pigment information layer 2. The pigment information layer 2 is responsible for providing rich color variations. The refractive layer 1 allows light to undergo specific refraction and reflection as it passes through, creating an optical effect similar to the upper layer of chameleon skin, achieving dynamic color changes. The pigment information layer 2 consists of a ring-shaped pigment layer 21 and a central white cylinder 22 aligned with a circular hole 210 in the middle of the ring-shaped pigment layer 21. When light passes through the upper transparent refractive layer 1 and shines on the pigment information layer 2 and is reflected, these colors are projected at specific angles, creating a stunning color effect. The refractive index of the refractive layer 1 is between 1.5 and 1.8.

[0051] In this embodiment, the annular pigment layer 21 is configured as a planar ring with a central circular hole 210. The planar ring is divided into six sector-shaped blocks. The first, third, and fifth sectors along the circumference are each assigned one of three base colors, while the second, fourth, and sixth sectors are each assigned one of three transition colors. The transition colors are mixtures of two adjacent base colors. In this embodiment, the first, third, and fifth sectors are assigned red, yellow, and black, respectively, while the second, fourth, and sixth sectors are assigned red-yellow, yellow-black, and black-red transition colors, respectively. The three base colors—red, yellow, and black—correspond to the colors of three pigment cells in the dermis of cephalopods. The transition colors formed by the fusion of two adjacent base colors correspond to the color mixing effect produced by changes in the area of ​​cephalopod pigment cells. The central white cylinder 22 below the annular pigment layer 21 is a biomimetic simulation of the white body cells at the bottom of the dermis of cephalopods. Its function is to effectively and comprehensively reflect the light incident from the top (the incident light at an angle of 90±10° with the bottom surface), so that the model can present a better overall color effect from a top-down perspective.

[0052] The three mixed transition colors formed on the annular pigment layer 21 fundamentally solve the problem of discontinuous color transitions (color transitions) that occur in existing visual illusion materials as the viewing angle changes, thereby improving the softness and smoothness of the visual experience while widening the range of viewing angles.

[0053] The radius of the circular hole 210 in the annular pigment layer 21 is r, the radius of the planar annulus is 2.9r-2.95r, and the thickness is 0.4-0.6r. The radius of the central white cylinder 22 is equal to that of the circular hole 210, and the height is 0.4-0.6r. The bottom radius of the refractive layer 1 is larger than that of the annular pigment layer 21, which can be set to 3-3.2r, and is larger than the outer radius of the annular pigment layer 21. The height of the refractive layer 1 is 6.35r-6.5r, which facilitates the complete coverage of the annular pigment layer 21 and the central white cylinder 22 within its lower part. The bottom of the central white cylinder 22 is flush with the bottom surface of the refractive layer 1, and there is a gap of 0.25-0.32r between the top surface of the central white cylinder 22 and the planar annulus. The central white cylinder 22 can effectively mask and integrate the pigment color on the planar annulus when the viewing angle changes. In this embodiment, when viewed from a top-down perspective, the annular pigment layer 21 and the central white cylinder 22 do not obstruct each other, and the annular pigment layer 21 and the fan-shaped areas of color on its surface 6 and the central white cylinder 22 can be seen.

[0054] The distance between the top surface of the central white cylinder 22 and the planar ring allows the surrounding annular pigment layers 21 to surround the central white cylinder 22, forming a three-dimensional layered structure with a certain height difference. This height difference causes the annular pigment layers 21 with rich colors to stack and obscure the central white cylinder 22, which helps to reduce the chaotic visual effect caused by seeing the central white cylinder 22 from the side viewing angle, and improves the complete sensory experience of visual observation.

[0055] When incident light enters, it is transmitted and refracted through the upper transparent refractive layer 1 before reaching different sector blocks of the lower pigment information layer 2. The pigment information layer 2 absorbs and reflects the incident light according to the set color type. Finally, the reflected light is reflected again through the refractive layer 1, forming the visual presentation of color. By utilizing the specific structure of the above model unit, and by combining variations in the array of model units, different and wondrous visual effects can be created. The refractive index and shape of the refractive layer 1, as well as the arrangement of different color blocks in the pigment information layer 2, directly affect the observation effect.

[0056] The model unit structure in this embodiment is the best simulated model of skin discoloration in cephalopods in various embodiments, based on experimental comparisons. It is the most concise, easiest to prepare with new materials through voxel 3D printing, and saves material costs.

[0057] The radius r of the circular hole 210 in the annular pigment layer 21 can be 0.95–1.1 mm. When r = 1 mm, the outer radius of the annular pigment layer 21 is 2.95 mm, the thickness of the planar ring is 0.5 mm, the radius of the central white cylinder 22 is 1 mm, the height is 0.5 mm, and there is a height gap of 0.25 mm between the top surface of the central white cylinder 22 and the bottom surface of the planar ring. The bottom radius of the refractive layer 1 is 3.0 mm, and the height is 6.35 mm. Since the refractive layer 1 is a semi-spherical, that is, a semi-spherical, is a rotational ellipsoid formed by rotating around the major axis of an ellipse, the major axis of which is 12.7 mm (6.35 mm × 2), and the minor axis is 6.0 mm (3.0 mm × 2).

[0058] Model units were constructed and arrayed according to the above specifications to obtain a model for preparing the visual illusion material. Using Stratasys full-color 3D printing technology, the annular pigment layer 21 and the central white cylinder 22 in the pigment information layer 2 were printed using a colored photosensitive polymer material, and the refractive layer 1 was printed using a transparent photosensitive polymer material with a refractive index of 1.56. After 3D printing, the material was cured and set under 500W UV light for 3 minutes, resulting in a visual illusion material based on the skin color-changing mechanism of cephalopods. A photograph of the prepared visual illusion material is shown below. Figure 2 As shown.

[0059] The illusory material prepared using the model in Example 1 exhibits a detailed and broad color gamut, as well as smooth color transition properties: the observed colors subtly change as the viewing angle shifts horizontally. Figure 2 In (a), (b), and (c), observations are taken from three different diagonals of the model unit array, with a 50° longitudinal tilt angle (the angle between the line of sight and the horizontal line) as the viewing angle. Different color changes are observed from different viewing positions. (d) shows the visual effect when the longitudinal tilt angle of the viewing angle is 90° (i.e., a top-down view), where the model units all turn white (all displaying the color of the central white cylinder). Compared with other embodiments, the model designed in this embodiment is the most streamlined model structure for preparing optical illusion materials and achieving optical illusion effects, featuring cost savings and the most delicate color rendering.

[0060] Example 2

[0061] The model constructed in this embodiment differs from that in Embodiment 1. The main difference is that the pigment information layer 2 still includes a ring-shaped pigment layer 21 and a central white cylinder 22. The difference is that, as shown in the figure... Figure 3The side view (see Figure a), top view (see Figure b), and perspective view (see Figure c) of the model unit in Embodiment 2 are shown. In this embodiment, the annular pigment layer 21 is an open stepped ring structure composed of three congruent fan rings with an arc of 150-180 degrees, with adjacent fan rings overlapping end to end. The uppermost fan ring 213 and the lowermost fan ring 211 are connected by an intermediate fan ring 212. Each fan ring is horizontally arranged, with an equal thickness of 0.9r-1.1r. The horizontal height of the three fan rings 211, 212, and 213 increases sequentially by one fan ring thickness. The arc of the three fan rings 211, 212, and 213 is 180 degrees, with each end overlapping by 60 degrees, and the remaining unoverlapped arc is also 60 degrees. Thus, the entire stepped ring structure can be divided into 6 fan ring blocks.

[0062] The three sector rings 211, 212, and 213 are each composed of pigment particles of different sizes. These pigment particles are actually short cylindrical rods perpendicular to the bottom surface of the refractive layer. The pigment particles near the circular hole 210 have smaller radii, while those near the edge of the annular pigment layer 21 have larger radii. The pigment particles in each sector ring have larger radii near the center line, and their radii gradually decrease as they develop towards both sides of the center line. Two types of mixed pigment particles are randomly mixed at the overlapping part of two adjacent sector rings, while the remaining parts are composed of pure-colored pigment particles.

[0063] like Figure 3 As shown, the bottom surfaces of the lower fan ring 211 and the central white cylinder 22 are flush with the bottom surface of the refractive layer 1, and their pure-color pigment particles are dark brown. The pure-color pigment particles of the middle fan ring 212 are yellow, and the pure-color pigment particles of the upper fan ring 213 are red. The overlapping area between the lower fan ring 211 and the middle fan ring 212 is a mixture of dark brown and yellow pigment particles; the overlapping area between the middle fan ring 212 and the upper fan ring 213 is a mixture of yellow and red pigment particles; and the overlapping area between the upper fan ring 213 and the lower fan ring 211 is a mixture of dark brown and red pigment particles. The dark brown pigment particles, the mixed dark brown and yellow pigment particles, the yellow pigment particles, the mixed yellow and red pigment particles, the red pigment particles, and the mixed dark brown and red pigment particles each occupy a 60-degree arc in the annular pigment layer 21.

[0064] This embodiment provides a relatively intuitive simulation of the color-changing principle of cephalopod skin. The three fan-shaped rings 211, 212, and 213 are constructed based on the three layers of pigment cells in the skin of cephalopods, and the three types of pure-colored pigment particles simulate the corresponding colors of these pigment cells. Because the horizontal heights of the three fan-shaped rings 211, 212, and 213 increase sequentially by one ring thickness, forming a stepped shape, the height difference between the three rings results in varying degrees of obscuring of the central white cylinder 22, which helps to subtly adjust the visible area of ​​the central white cylinder 22. The pigment particles of different radii within each fan-shaped ring 211, 212, and 213 simulate the state of the pigment cells in the skin of cephalopods during the color-changing process. In this embodiment, the larger radius pigment particles simulate the stretched state of the pigment cells in the skin of cephalopods, while the smaller radius pigment particles simulate the contracted state. Simultaneously, the overlapping areas exhibit a mixture of two types of pigment particles, simulating the color mixing effect of pigment cells. The irregular and random mixing of pigment particles of different colors can present a natural color mixing effect at the macroscopic level. Due to the inkjet principle of inkjet voxel 3D printing technology, the visual illusion material is prepared to form a natural color mixing and present a macroscopic visual effect of six color blocks.

[0065] Model units were constructed according to the above dimensions of r=1mm and three fan-ring thicknesses of 1mm, and then arrayed to obtain a model for preparing the visual illusion material. Using Stratasys full-color 3D printing technology, the annular pigment layer 21 and the central white cylinder 22 in the pigment information layer 2 were printed with a colored photosensitive polymer material, and the refractive layer 1 was printed with a transparent photosensitive polymer material with a refractive index of 1.56. After 3D printing, the material was cured and set under 500W UV light for 3 minutes, resulting in a visual illusion material based on the color-changing mechanism of cephalopod skin.

[0066] The physical photographs of the illusory material prepared using the model of Example 2 are similar in effect to those of Example 5, with clearer color changes and obvious phased changes.

[0067] Example 3

[0068] The model constructed in this embodiment differs from that in Embodiment 1. The main difference is that the pigment information layer 2 still includes a ring-shaped pigment layer 21 and a central white cylinder 22. The difference is that, as shown in the figure... Figure 4The side view (see Figure a), top view (see Figure b), and perspective view (see Figure c) of the model unit of Embodiment 3 are shown. In this embodiment, the annular pigment layer 21 is an open stepped ring structure composed of six congruent fan rings with an arc of 60 degrees. Adjacent fan rings are arranged upwards layer by layer with a height equal to 1 / 2 fan ring thickness (i.e., 0.25r). There is a height difference of 2 fan ring thickness (1.0r) between the top and bottom fan rings. The first, third, and fifth fan rings along the circumferential direction are respectively given three base colors, and the second, fourth, and sixth fan rings are respectively given three transition colors. The transition colors are mixed transition colors of two adjacent base colors. For example, in this embodiment, the first, third, and fifth fan rings are respectively given dark brown, yellow, and red, and the second, fourth, and sixth fan rings are respectively given ochre, orange, and dark red. The bottom surfaces of the first fan ring and the central white cylinder are flush with the bottom surface of the refractive layer. The radius of the circular hole 210 in the annular pigment layer 21 is r, the outer radius of the annular pigment layer 21 is 2.95r, and the thickness of each fan ring is equal, which is 0.5r. Among them, r is preferably 1.0 mm.

[0069] This embodiment is a secondary abstraction and refinement based on Embodiment 2. The annular pigment layer 21 has a six-layer fan-ring structure, each of which is assigned three base colors and three mixed transition colors. The base colors are designed based on the three layers of pigment cells in the skin of cephalopods, and the mixed transition colors are the fusion effect of adjacent base colors. The color settings of the six color blocks are very close to the macroscopic visual effect of the six color blocks presented in Embodiment 2. In this embodiment, the six fan-rings of the annular pigment layer 21 do not obstruct each other from the central white cylinder, and all parts of the pigment information layer 2 can be seen from the top surface.

[0070] An array of the aforementioned model units was formed to obtain a model for preparing the visual illusion material. Using Stratasys full-color 3D printing technology, the annular pigment layer 21 and the central white cylinder 22 in the pigment information layer 2 were printed using a colored photosensitive polymer material, while the refractive layer 1 was printed using a transparent photosensitive polymer material with a refractive index of 1.56. After 3D printing, the material was cured and set under 500W UV light for 3 minutes, resulting in a visual illusion material based on the skin color-changing mechanism of cephalopods. A photograph of the prepared visual illusion material is shown below. Figure 5 As shown.

[0071] The visual illusion material prepared using the model in Example 3 exhibits a relatively detailed and well-defined color gamut, as well as distinct color transition properties: when the viewing angle changes horizontally, the observed color also undergoes a clear, phased change. For example... Figure 5In (a), (b), and (c), observations are taken diagonally from the model unit array, with a 50° longitudinal tilt angle (the angle between the line of sight and the horizontal line) as the viewing angle. Different color changes are observed from different viewing positions. When the viewing angle is 90° longitudinal tilt angle (vertical top-down view), the observed color becomes white (the color of the central white cylinder), and the actual effect is the same as in Example 1 above. Figure 2 The effect of (d) is basically the same.

[0072] Example 4

[0073] The model constructed in this embodiment differs from that in Embodiment 1. The main difference is that the pigment information layer 2 still includes a ring-shaped pigment layer 21 and a central white cylinder 22. The difference is that, as shown in the figure... Figure 6 The side view (see Figure a), top view (see Figure b), and perspective view (see Figure c) of the model unit in Embodiment 4 are shown. In this embodiment, the annular pigment layer 21 is a closed-loop stepped ring structure composed of six congruent fan rings with an arc of 60 degrees connected together. The first to fourth fan rings are arranged upwards layer by layer with a thickness of 1 / 2 fan ring, but the fourth to sixth fan rings are arranged downwards layer by layer with a thickness of 1 / 2 fan ring, so that the sixth fan ring is 1 / 2 fan ring thicker than the first fan ring, and the tail end of the sixth fan ring is connected to the starting end of the first fan ring.

[0074] The first, third, and fifth fan rings, counting along the circumference, are each given three base colors, while the second, fourth, and sixth fan rings are each given three transition colors, which are mixtures of two adjacent base colors. For example, in this embodiment, the first, third, and fifth fan rings are given dark brown, yellow, and red, respectively, while the second, fourth, and sixth fan rings are given ochre, orange, and dark red, respectively. The bottom surfaces of the first fan ring and the central white cylinder are flush with the bottom surface of the refractive layer. The radius of the circular hole 210 in the annular pigment layer 21 is r, the outer radius of the annular pigment layer 21 is 2.95r, and each fan ring has an equal thickness of 0.5r. Preferably, r is 1.0 mm.

[0075] This embodiment is an improved model based on embodiment 3 with structural optimization. The annular pigment layer 21 has a 6-layer fan-ring structure, each fan-ring being assigned three base colors and three mixed transition colors. The base colors are designed based on the three layers of pigment cells in the skin of cephalopods, and the mixed transition colors are the fusion effect of adjacent base colors. Unlike embodiments 2 or 3, the annular pigment layer 21 in this embodiment is a closed-loop structure. Therefore, compared to embodiment 3, this embodiment can increase visual continuity, and while maintaining visual appeal, it makes the overall module shape more aesthetically pleasing. In this embodiment, all parts of the pigment information layer 2 can be seen from the top surface.

[0076] An array of the aforementioned model units was formed to obtain a model for preparing the visual illusion material. Using Stratasys full-color 3D printing technology, the annular pigment layer 21 and the central white cylinder 22 in the pigment information layer 2 were printed using a colored photosensitive polymer material, while the refractive layer 1 was printed using a transparent photosensitive polymer material with a refractive index of 1.56. After 3D printing, the material was cured and set under 500W UV light for 3 minutes, resulting in a visual illusion material based on the skin color-changing mechanism of cephalopods. A photograph of the prepared visual illusion material is shown below. Figure 7 As shown.

[0077] The illusory material prepared according to the model in Example 4 has a relatively detailed and defined color gamut, as well as a clear color-changing performance, and its color-changing effect is very close to that of Example 3. Figure 7 Images (a), (b), and (c) are all observed diagonally across the model unit array, with a 50° longitudinal tilt angle as the viewing perspective. Different color changes can be observed depending on the viewing angle. When the viewing angle is 90° longitudinal tilt (vertical top-down view), the observed color becomes white (the color of the central white cylinder), and the actual effect is the same as in Example 1 above. Figure 2 The effect of (d) is the same.

[0078] Example 5

[0079] This embodiment differs from the model constructed in Embodiment 1, primarily in that the pigment information layer 2 still includes an annular pigment layer 21 and a central white cylinder 22. However, as shown in Figure 8, the side view (see Figure a), top view (see Figure b), and perspective view (see Figure c) of the model unit in Embodiment 5, the annular pigment layer 21 in this embodiment is a three-dimensional ring. It is obtained by processing the height difference between two adjacent fan rings in the closed-loop stepped ring structure of the annular pigment layer 21 in Embodiment 4 into a gentle slope, and then further processing it into a continuous and smooth curved surface. An angle is formed between the three-dimensional ring and the bottom surface of the refractive layer, but the surface of the three-dimensional ring is not a standard inclined plane. The lowest point of the bottom surface of the three-dimensional ring and the bottom surface of the central white cylinder are both level with the bottom surface of the refractive layer. The thickness of the three-dimensional ring is 0.6r-0.75r, where r is preferably 1 mm, and the thickness of the three-dimensional ring is preferably 0.6 mm.

[0080] This embodiment is an improved model based on embodiment 4 with structural optimization. Unlike embodiment 4, this embodiment improves the closed-loop stepped ring structure of the annular pigment layer 21 in embodiment 4 into a smooth curved surface, which can be considered as an abstract refinement of the "closed-loop stepped ring structure".

[0081] The difference between this embodiment and embodiments 2-4 is that embodiments 1 and this embodiment fill the spaces between the two base colors with gradient transition colors. In this embodiment, the three-dimensional ring is divided into 6 blocks, with red, red-yellow gradient transition color, yellow, yellow-black gradient transition color, black, and black-red gradient transition color set sequentially. This minimizes the abruptness and unevenness of color transitions, resulting in a smooth and continuous visual transition of color in the visual illusion material prepared based on the model as the viewing angle changes. Furthermore, similar to embodiment 1, the integrity of the pigment information layer 2 improves the visual appeal of the design while reducing the technical difficulty of preparing the angle-changing color material and minimizing material consumption.

[0082] An array of the aforementioned model units was formed to obtain a model for preparing the visual illusion material. Using Stratasys full-color 3D printing technology, the annular pigment layer 21 and the central white cylinder 22 in the pigment information layer 2 were printed using a colored photosensitive polymer material, while the refractive layer 1 was printed using a transparent photosensitive polymer material with a refractive index of 1.56. After 3D printing, the material was cured and set under 500W UV light for 3 minutes, resulting in a visual illusion material based on the skin color-changing mechanism of cephalopods. A photograph of the prepared visual illusion material is shown below. Figure 9 As shown.

[0083] The illusory material prepared using the model of Example 5 exhibits a detailed and broad color gamut, as well as smooth color transition properties. Its color-changing performance is very close to that of Example 1, with the best purity in yellow and red. Figure 9 As shown in (a), (b), and (c), observations are taken diagonally from the model unit array, with a 50° longitudinal tilt angle as the viewing perspective. Different visual perspectives reveal different color changes. When the viewing angle is 90° longitudinal tilt (vertical top-down view), the observed color becomes white (the color of the central white cylinder). The actual effect is similar to that of Example 1 described above. Figure 2 The effect of (d) is the same.

[0084] In summary, unlike existing models of cephalopod skin, the visual illusion material model of this invention includes a long spherical refractive layer with a smooth curvature change in its outer contour. Furthermore, the structure of the pigment information layer has been optimized by adding neutral white cylinders. Based on model construction and verification with a ray tracing rendering engine, the model units of this invention enable the material to exhibit excellent visual illusion color-changing effects. All embodiments effectively simulate the color-changing effect of cephalopod skin, effectively solving the visual problems associated with visual illusion materials and improving the hue scale range of color changes.

[0085] Among them, by changing the viewing angle, Examples 3-4 can achieve switching between 6 colors; while the three-dimensional ring, pigment particle aggregation ring and planar ring of Examples 1, 2 and 5 have a softer color visual transition and do not have the visual feeling of broken color blocks, achieving a more delicate and rich color change effect. The actual effect is that the natural transition color change effect between 8 to 10 colors (theoretically countless colors) can be observed with the naked eye.

[0086] Furthermore, the proposed solution significantly expands the observation angle range of the visual illusion material, enabling the visual illusion material simulating the color-changing effect of cephalopod skin to achieve a complete color display from a top-view perspective, a function that existing similar visual illusion materials cannot achieve. Simultaneously, the invention also expands the angular range from which the color can be observed completely, with an overall angular expansion rate of approximately 40%.

[0087] This invention provides a model based on the color-changing mechanism of cephalopod skin and a method for preparing illusory materials based on this model. When the curvature, height, and radius of the refractive layer 1 are similar to, but not entirely identical to, those in the above embodiments, the color-changing effect of the prepared illusory material will be weakened, but a less complete color-changing effect can still be achieved. The type and quantity of pigments applied to the annular pigment layer 21 can be replaced to obtain different color-changing effects; while the thickness, radius, number of three-dimensionally distributed layers, and stacking method of the annular pigment layer 21 can be slightly adjusted to achieve similar color-changing effects. The central white cylinder 22 located at the bottom of the pigment information layer 2 is also variable, including minor adjustments to its radius, thickness, and longitudinal position; for example, when the position of the central white cylinder 22 undergoes a short vertical displacement or a slight increase in height (e.g., ... Figure 10 As shown, the visual illusion color-changing effect will produce subtle changes, but it can still achieve a similar visual illusion effect in general. In embodiments 3-5 of this invention, the models are all obtained by the inventors after optimization. In these embodiments, the bottom layer of the annular pigment layer 21 and the central white cylinder 22 are on the same layer. In this way, while achieving a clear and distinct top visual effect, the simplicity of the shape is improved, thereby reducing production difficulty and material consumption in the production process.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions, or combinations of technical features in the above embodiments that do not conflict with each other, can be made in accordance with the manner described in the embodiments. These modifications, substitutions or combinations do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A model based on the skin color change mechanism of cephalopods, characterized in that, include: Several model units arranged in an array, each model unit containing a refractive layer and a pigment information layer; The refractive layer refracts the incident light, and the pigment information layer carries pigment information; The pigment information layer includes an annular pigment layer with a circular hole at its center. Colors are distributed in blocks on the annular pigment layer. A central white cylinder is also provided at the circular hole aligned with the center of the pigment information layer. The central white cylinder is located below the annular pigment layer and has a gap between it and the annular pigment layer, or the central white cylinder is located in the circular hole of the annular pigment layer. The top view of the annular pigment layer of the pigment information layer is a ring, and the ring has three solid color blocks spaced apart from each other, with a mixed transition color block formed between two adjacent solid color blocks; The refractive layer is a continuous transparent medium, shaped like a hemispherical shape with a circular cross-section. The refractive layer completely covers the pigment information layer inside the refractive layer, near its bottom. The bottom surface of the central white cylinder is flush with the bottom of the refractive layer. In the top view of the annular pigment layer, the inner radius of the ring is r, the outer radius is 2.9r-2.95r, and the radius of the central white cylinder is equal to the inner radius of the ring, which is r. The bottom radius of the refractive layer is 3r-3.2r, and the height of the refractive layer is 6.35r-6.5r. The height of the central white cylinder is 0.4-0.6r; where r = 1-1.2 mm. The annular pigment layer is an open stepped ring structure composed of six congruent fan rings with an arc of 60 degrees. The adjacent fan rings are arranged layer by layer upwards with a thickness of 1 / 2 fan ring. There is a height difference of 2 fan ring thickness between the top fan ring and the bottom fan ring. The first, third, and fifth fan rings along the circumference are each assigned one of three base colors, and the second, fourth, and sixth fan rings are each assigned one of three transition colors. The transition colors are a mixture of two adjacent base colors. The bottom surfaces of the first fan ring and the central white cylinder are flush with the bottom surface of the refractive layer. Each fan ring has the same thickness, ranging from 0.4r to 0.6r.

2. A method for preparing a visual illusion material based on the skin color-changing mechanism of cephalopods, characterized in that, include: Modeling was performed according to the model based on the skin discoloration mechanism of cephalopods as described in claim 1; Then, using Stratasys full-color 3D printing technology, the pigment information layer is printed with colored photosensitive polymer material, and the refractive layer is printed with transparent photosensitive polymer material. After printing, the material is cured under UV light to obtain the visual illusion material based on the color-changing mechanism of cephalopod skin.

3. The preparation method according to claim 2, characterized in that, The refractive index of transparent photosensitive polymer materials is 1.5-1.

8.

4. A visual illusion material based on the color-changing mechanism of cephalopod skin, characterized in that, It is prepared by the preparation method described in claim 2 or 3.

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