Bionic pressure-resistant cylinder based on cuttlebone and application

Abstract

The invention discloses a bionic pressure-resistant cylinder based on cuttlebone, the bionic pressure-resistant cylinder sequentially comprises a central cylinder and a plurality of layers of laminates in concentric circle configuration from inside to outside, each layer of laminates is provided with an inner wall, the inner wall is an asymmetric S-shaped wave wall, and the inner wall is provided with a plurality of grooves. A cavity defined by the laminates and the asymmetric S-shaped wave walls extends in the axial direction of the cylinder. The invention further discloses application of the bionic pressure-resistant cylinder to an underwater lighting module, a deep-sea unmanned underwater vehicle AUV / ROV shell, a conveying pipeline or a buried pipeline. The space stability and the omnidirectional water pressure resistance of the bionic pressure-resistant cylinder are remarkably enhanced, and the problem that light weight and high pressure resistance are difficult to consider due to the fact that a cylindrical material is prone to buckling is solved.

Description

Technical Field

[0001] This invention belongs to the field of biomimetic deep-sea pressure-resistant technology, and specifically relates to a biomimetic pressure-resistant cylinder based on cuttlebone and its application. Background Technology

[0002] Currently, in applications such as deep-sea equipment, submarine pressure hulls, and transportation systems (e.g., buried oil and gas pipelines), closed pipe structures made of metal or polymer materials are commonly used to resist external hydrostatic or gravitational pressure. Typical structural forms include: on the one hand, stainless steel or titanium alloy hulls, due to their high strength and pressure-bearing capacity, are often used in deep-sea submersibles and high-pressure vessels. However, these materials have high density, resulting in a high overall structural mass, which is not conducive to achieving system lightweighting, and also increases manufacturing and maintenance costs. On the other hand, polyvinyl chloride (PVC) or other polymer pipes are widely used in transportation systems due to their light weight and low cost. However, these materials have weak mechanical properties, especially prone to instability and collapse under large deformation or external pressure conditions, making them unsuitable for high-pressure bearing requirements in extreme environments. In summary, existing pressure hull and pipe materials generally suffer from problems of "high mass and high cost" or "insufficient pressure-bearing capacity," and most structures rely on a single material or configuration, lacking a multi-scale collaborative design mechanism, making it difficult to simultaneously meet multiple performance requirements such as "lightweight, high strength, and buckling resistance."

[0003] Organisms often utilize simple, low-density materials to adapt to extreme environments through complex multi-scale structural designs. For example, cuttlefish bone is composed only of brittle materials such as calcium carbonate and protein, with a density of only 0.2-0.6 g / cm³. 3 It can withstand hydrostatic pressure at depths of 100-800 meters, demonstrating exceptional pressure resistance. This superior performance is primarily attributed to its unique multi-stage structure, which allows it to maintain its lightweight properties while possessing outstanding pressure resistance.

[0004] Inspired by this, researchers have recently begun to explore the creation of artificial materials with a cuttlebone-like structure for applications such as impact resistance, heat insulation, and noise reduction. However, most current biomimetic research employs flat-plate designs, primarily producing pressure-resistant plate-like specimens under uniaxial loading conditions. For instance, Chinese patent CN113561472A discloses a method for preparing a lightweight, high-strength cuttlebone-like material with shape memory function: a three-dimensional model of a cuttlebone-like structure is designed and constructed, and the cuttlebone-like structure is 3D printed using photosensitive resin with shape memory function; the cuttlebone-like structure includes a layered porous structure composed of upper and lower plates and sinusoidal wave plates; multiple sinusoidal wave plates are evenly distributed parallel to each other between the upper and lower plates and perpendicular to them; the sinusoidal wave plates are arranged asymmetrically. Chinese Patent CN118998238A discloses a spiral impact-resistant structure with biomimetic gradient sinusoidal wave walls and its preparation method, comprising: at least two porous structural layers; each porous structural layer includes an upper plate, a lower plate, and a biomimetic gradient sinusoidal wave wall disposed between the upper plate and the lower plate; wherein the upper plate and the lower plate are arranged in parallel; the biomimetic gradient sinusoidal wave walls are perpendicular to the upper plate and the lower plate, and are arranged at equal intervals along the length direction and parallel along the width direction inside the space between the upper plate and the lower plate, while the amplitude and period of the sinusoidal wave wall vary gradiently along the height direction; each biomimetic gradient sinusoidal wave wall is a biomimetic gradient sinusoidal wave wall that imitates the gradient of a cuttlebone.

[0005] The limitations of this two-dimensional planar structure design make it difficult to directly apply to complex three-dimensional pressure scenarios, limiting its application in actual working conditions such as underwater lighting modules, deep-sea unmanned underwater vehicle (AUV / ROV) hulls, and delivery pipelines. Summary of the Invention

[0006] The purpose of this invention is to provide a biomimetic pressure-resistant cylinder based on cuttlebone. This biomimetic pressure-resistant cylinder has significantly enhanced spatial stability and resistance to omnidirectional water pressure, solving the problem that cylindrical materials are prone to buckling, making it difficult to achieve both lightweight and high pressure resistance.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A biomimetic pressure-resistant cylinder based on cuttlebone, the biomimetic pressure-resistant cylinder comprising, from the inside out, a central cylinder and several layers of concentric circular plates, each layer of plates having an inner wall, the inner wall being an asymmetrical S-shaped wave wall, the cavity formed by the plates and the asymmetrical S-shaped wave wall extending along the cylinder axis.

[0008] Preferably, the biomimetic pressure-resistant cylinder has a porosity of 65-90%.

[0009] The compressive strength of porous materials varies significantly with density: At the upper limit, cuttlebone's natural porosity ranges from 90% to 93%, enabling it to survive in the deep sea at extremely low densities. According to biomimetic principles, this represents the highest porosity condition for maintaining good structural stability. At the lower limit, even using the lightest 3D-printed alloy (aluminum alloy) to prepare the material, the overall density in water is ≤1 g / cm³. 3 It requires a porosity of at least 65%.

[0010] Preferably, the inner walls of each layer are evenly distributed, and the walls of adjacent layers are staggered.

[0011] This arrangement effectively avoids local instability caused by overlapping stress paths in multi-story structures. By dispersing external loads and delaying buckling and local failure, it significantly improves the overall stability and compressive strength of the structure. Simultaneously, this staggered structure design enhances the gradual and robust nature of the failure process, contributing to improved safety and service reliability in high-pressure environments such as deep seas. Furthermore, based on hydrostatic simulation results of staggered arrangements and models at the same location, the staggered arrangement exhibits higher compressive strength.

[0012] Preferably, in two adjacent layers, the number of inner walls on the outer layer is twice that on the inner layer.

[0013] As the cylinder diameter increases, the circumference of the outer shell increases significantly. If the increase in the number of walls is insufficient, each wall must bear a longer circumferential support, leading to local instability and structural softening. When the number of walls increases by more than twice, the exponential increase in the number of walls per layer results in: increased manufacturing complexity; reduced thickness of individual walls due to limited overall material usage; and insufficient stiffness, even buckling risk, due to thinner walls. Therefore, "twice" is considered a balance point between structural efficiency, manufacturing complexity, and mechanical performance.

[0014] Preferably, in two adjacent layers, the ratio of the inner layer height to the outer layer height is 0.9-1.5.

[0015] To facilitate actual manufacturing and control of biomimetic effects, a layer height gradient coefficient (γ = h) is introduced. n / h n-1 The ratio of the height of the inner layer to the height of the outer layer in two adjacent layers is defined as being within the range mentioned above.

[0016] Further preferably, the spacing between the layers has a gradient that increases from the outside to the inside. That is, 1 < γ ≤ 1.5.

[0017] First, this invention simulates the gradient configuration of "gradually increasing layer height from the outside to the inside" based on the biomimetic principle of natural cuttlebone structure: the cross-section of natural cuttlebone shows that the outer layer near the ventral side is a compact structure with low layer height and high density, while the inner layer transitions to a loose structure with high layer height and low density; this invention embodies the wisdom of biomechanical evolution. Second, from the perspective of structural stability, the outer cylindrical radius is larger, and the total water pressure load it bears is also greater, making it more prone to instability; if a smaller layer height (i.e., smaller interlayer spacing) is used, the structural compactness of this area can be enhanced, the local buckling threshold of the outer layer can be increased, and the deformation concentration caused by water pressure can be reduced; the inner area can use a larger interlayer spacing: reducing material usage, providing more usable cavity space, facilitating the installation of electronic devices, buoyancy modules, etc.; therefore, overall, the gradient layer height of dense outer layer and sparse inner layer can achieve a comprehensive balance between "mechanical performance" and "functional space". Finally, finite element simulation analysis shows that, under the same material and overall mass conditions, the interlayer spacing design with smaller outer layers and larger inner layers has a higher buckling load threshold and overall compressive stability. Compared with the equal spacing design, it exhibits better load uniformity and failure delay in hydrostatic pressure environment. This verifies that the biomimetic gradient design is not only reasonable, but also can improve the overall pressure resistance performance in engineering implementation.

[0018] Preferably, the biomimetic pressure-resistant cylinder comprises 1-4 layers of plates.

[0019] Preferably, the density of the biomimetic cylinder is 0.15-1 g / cm³. 3 .

[0020] If the structural density is greater than 1.0 g / cm³ 3 If this occurs, negative buoyancy will be generated in the water, requiring external auxiliary floats for balance, increasing system complexity; if the structural density is significantly less than 0.15 g / cm³... 3 If the structure is not sufficiently mechanically intact, it will be prone to local buckling or overall collapse. Therefore, this invention ensures that the biomimetic pressure-resistant cylinder still has buoyancy control capability in the deep-sea environment by limiting the density of the biomimetic pressure-resistant cylinder, thereby greatly reducing the complexity of additional pontoon systems or structural supports.

[0021] The present invention features a multi-chamber cylindrical structure with high design flexibility. Its density can be adjusted to achieve 0.2-1 g / cm³. 3 The continuous density range allows for adaptation to different working conditions. Furthermore, load distribution can be controlled by adjusting design parameters such as the mass distribution between the panels and walls, the period length of the corrugated wall, and the number of periods, thereby improving material utilization and structural efficiency.

[0022] As an example, the general mathematical description of the constructed asymmetric wave wall is a parametric curve, specifically a sine curve, expressed as follows:

[0023] Here, t is a variable varying between 0 and 1, 360 × t constitutes one complete period of the sine function, the diameter of the central column of the model is 1.5, and A = 0-0.8 represents the curve amplitude. Theoretically, the model can extend infinitely along its axis; here, L = 30 mm is chosen to represent the total length of the model, and P = 2 represents the number of curve periods, i.e., 15 periods. The optimized ratio of wall thickness to layer thickness is 0.346.

[0024] In this invention, the periods of the upper and lower ends of the asymmetrical S-shaped wave wall are the same, but the amplitudes are not necessarily equal. The end facing the outer wall of the cylinder has a larger amplitude than the end facing the central column.

[0025] The biomimetic cylinder can be fabricated using various 3D printing technologies such as stereolithography (SLA), fused deposition modeling (FDM), digital light processing (DLP), two-photon polymerization (TPP), powder bed fusion (PBF), or selective laser sintering (SLS).

[0026] In addition to resin materials, the biomimetic pressure-resistant cylinder provided by this invention can also be made of metal, ceramic or materials of different stiffness through multi-material printing or composite preparation.

[0027] The present invention also provides the application of the above-mentioned biomimetic pressure-resistant cylinder in underwater lighting modules, deep-sea unmanned underwater vehicle (AUV / ROV) shells, delivery pipelines or buried pipelines.

[0028] When the biomimetic pressure-resistant cylinder is made of 3D-printed high-strength and high-toughness resin, the material selection has good formability and pressure resistance, facilitating engineering application deployment. The biomimetic pressure-resistant cylinder provided by this invention, while meeting the requirements of lightweight and pressure resistance, also features an internal hollow cavity that can be used to embed electronic components or optical devices, achieving integrated structure and function, making it suitable for applications such as deep-sea equipment or buried pipelines.

[0029] Compared with existing technologies, the biomimetic pressure-resistant cylinder provided by this invention has achieved excellent technical effects in terms of structural configuration, mechanical properties, and functional adaptability. Specifically: (1) Structural configuration differences: The flat plate is transformed into a multi-layered cylindrical shell. Existing imitation squid bone structural materials mostly adopt a two-dimensional flat plate configuration, which is only suitable for unidirectional compression testing and cannot withstand three-dimensional complex loads, thus limiting their application in complex scenarios such as underwater. The structure proposed in this invention significantly enhances the spatial stability and resistance to omnidirectional water pressure, while also possessing the usability of internal space and meeting functional requirements such as adapter encapsulation and fluid conduction.

[0030] (2) Performance differences: Compression tests show that the peak load-bearing capacity of this invention is 1.57 times that of steel pipes of similar diameter and weight, and nearly 4 times that of PVC pipes. Furthermore, its unit strength at 5% strain is also superior to both. This significantly improves the structure's pressure resistance limit, deformation stability, and energy dissipation capacity, suppressing buckling instability and delaying structural failure in critical stress areas. If metal printing is used, this invention can achieve lightweight pressure resistance performance far exceeding that of existing pressure-resistant shells.

[0031] (3) The structure of the present invention has a closed or connected cavity space, which is not only used for weight reduction and buoyancy adjustment, but also for encapsulating functional devices such as sensors, light sources, and power systems, realizing the leap from structural carrier to multifunctional integrated system, and improving the miniaturization, integration and intelligence level of underwater equipment. Attached Figure Description

[0032] Figure 1 A schematic diagram of the design parameters of a single-layer structure of a biomimetic pressure-resistant cylinder based on cuttlebone, provided in Example 1; Figure 2 This is a schematic diagram of a biomimetic pressure-resistant cylindrical structure design based on cuttlebone, provided in Example 2. Figure 3 Photographs of the biomimetic pressure-resistant cylinder based on cuttlebone provided in Examples 1-3; Figure 4 The water pressure resistance test performance diagrams of the biomimetic pressure-resistant cylinder based on cuttlebone provided in Examples 1-3 and the traditional single-shell cylinder are shown. Figure 5 The pressure resistance diagram shows the pressure resistance performance of the cuttlebone-based biomimetic pressure-resistant cylinder used for buried pipelines in Example 3. Figure 6 This is a schematic diagram of the application of the biomimetic pressure-resistant cylinder based on cuttlebone provided in Example 3 in deep-sea lighting applications in Application Example 1; Figure 7 The water pressure test performance diagram for the biomimetic pressure-resistant cylinder based on cuttlebone provided in Example 3, which is used in underwater lighting applications, is shown in Application Example 1. Explanation of reference numerals in the attached diagram: 1. Central column; 2. S-shaped wave wall; 3. Shelf; 31. First shelf; 32. Second shelf; 33. Third shelf; 34. Fourth shelf. Detailed Implementation

[0033] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0034] Example 1 This embodiment provides a biomimetic pressure-resistant single-layer cylinder based on cuttlebone. Its fabrication includes the following steps: A cuttlebone-like cylinder model is created using Creo Parametric software. Considering the complexity of the parametric surface model, the model size is set to φ10*10mm. Once the three-dimensional geometric model is completed, the structure is scaled and extended using the 3D printing model processing software MaterialiseMagics to achieve large-size applications or pipes.

[0035] The same 3D geometry was built for both simulation and 3D printing to minimize discrepancies between experiments and simulations. All embodiment models had a porosity of 83.5%, close to that of natural cuttlebone.

[0036] These models are cylindrical structures oriented along the z-axis, with an internal multi-layered concentric circular structure supported by asymmetric S-shaped wave walls between layers, consisting of one layer. The central column 1 is a solid cylinder with a diameter of 1.5 mm. Layer 3 has a diameter of 10 mm and a thickness of 0.346 mm. For wave wall 2, a general mathematical description of the asymmetric S-shaped wave wall is constructed, with its parameterized curve being a sine curve, expressed as follows:

[0037] Where t is a variable varying between 0 and 1, and 360 × t constitutes a complete period of the sine function. 2 represents the curve period of 2 mm, and 30 represents the total length of the model of 30 mm. For the outer curve A = 0.7, and for the inner curve A = 0.6, the curve amplitude is represented. By projecting the parameterized curves on the xz plane along the y-axis onto the inner surface of the layer plate and the outer surface of the central column, respectively, the graphics at both ends of the asymmetric wave wall are obtained. The boundary between the two projection lines is merged to form a central surface, which is then given a thickness of 0.1038 mm, forming a parameterized asymmetric S-shaped wave wall. Using the generated wave wall 2 and the axis of the central column as the rotation axis, one wave wall is replicated every 72°, forming a circle of 5 asymmetric S-shaped wave walls. The central column, layer plate, and wave wall of the component are merged into a whole to complete the modeling of the biomimetic pressure-resistant single-layer cylinder. Figure 1 ).

[0038] The printed model was magnified 12 times and its length was increased by 1 time through an array method. The overall dimensions are φ120*240 mm, and the density is 0.19 g / cm³. 3 .

[0039] A biomimetic, pressure-resistant single-layer cylindrical material was fabricated using SLA 3D printing technology. The steps included: using commercially available photocurable resin C-UV 9400EF and a commercial 3D printer (SLA 600, JG MAKER, China), the resin was cured layer by layer via stereolithography during printing. To achieve higher print quality, the laser wavelength, laser power, spot diameter, printing speed, and layer thickness were set to 355 nm, 3 W, 0.2 mm, 10 mm / s, and 0.1 mm, respectively.

[0040] After printing, the model was immersed in ethanol for 3 minutes to remove uncured precursor solution and soften the support structure. The support was then carefully removed using tweezers to prevent damage to the model's thin-walled structure. Finally, the model underwent post-curing in a UV curing oven (J-600, JG MAKER, China) under the following conditions: 365 nm UV irradiation and an energy density of 3.5 mW / cm². 2 Exposure time was 15 min. All models were prepared under the same conditions.

[0041] The model used for the hydrostatic test had a 1 mm wide square strip and a rounded corner added around the outer edge of its end face. This was to enhance the sealing between the sample and the end caps during the hydraulic test and to prevent stress concentration. A 1 mm thick thin steel plate was bonded to both ends of the hydrostatic test model using high-strength epoxy adhesive to achieve a waterproof seal. The hydrostatic test was conducted using a hydrostatic testing apparatus. This apparatus consists of three parts: a pressure vessel, a pressurization system, and a monitoring system. The main components include a 500 mm diameter, 1500 mm long test chamber (using water as the medium), a plunger booster pump, an underwater camera, and pressure gauges. To reduce the influence of buoyancy, all samples were submerged in the test chamber with counterweights attached, ensuring complete submersion. At least three samples were tested for each group. The booster pump maintained a 3 Hz operating frequency throughout the venting and pressurization process. After venting, the pressure in the test chamber was maintained for 1 minute to ensure airtightness. The booster pump gradually increased the pressure at a rate of 0.5 MPa / min, while the pressure-time curve inside the chamber was recorded. The point of the first sudden drop in pressure was used as the basis for judging the pressure resistance stability of the material.

[0042] Example 2 This embodiment shares the same design, preparation, and experimental steps as Embodiment 1. The difference lies in that this embodiment has a 4-layer structure, thus the model has different overall dimensions, and the layer thickness and corrugated wall thickness are different, while other parameters remain the same.

[0043] From the inside out, the structure consists of a central column 1 and four concentric circular layers 3. The first layer 31, closest to the central column, has five asymmetrical S-shaped wave walls 2 evenly distributed; the second layer 32 has ten asymmetrical S-shaped wave walls evenly distributed; the third layer 33 has twenty asymmetrical S-shaped wave walls evenly distributed; and the fourth layer 34 has forty asymmetrical S-shaped wave walls evenly distributed. The asymmetrical S-shaped wave walls of adjacent layers are arranged alternately. Figure 2 The layer thickness is 0.4883 mm, and the asymmetric corrugated wall thickness is 0.10743 mm. The overall dimensions are φ30 mm * 10 mm, with a porosity of 83.5% and a density of 0.19 g / cm³. 3 .

[0044] The multi-layer model in this embodiment has the same layer spacing, and the distance between the center surfaces of adjacent layers is 10.

[0045] Example 3 This embodiment shares the same multilayer design, fabrication, and experimental steps as Embodiment 2. The difference lies in the layer height gradient of the 4-layer structure in this embodiment; the height of the inner layer relative to the outer layer between adjacent layers is constant, at 1.2. Therefore, the model has different layer spacing, and the layer thickness and corrugated wall thickness differ, while other parameters remain the same. Figure 3 ).

[0046] The distance between the central column 1 and the innermost layer 31 is 12.88 mm, the distance between the center surfaces of the innermost layer 31 and the second layer 32 is 10.73 mm, the distance between the center surfaces of the second layer 32 and the third layer 33 is 8.94 mm, and the distance between the center surfaces of the third layer 33 and the outermost layer 34 is 7.45 mm.

[0047] The layer thickness is 0.475 mm, and the asymmetric corrugated wall thickness is 0.1045 mm. The overall dimensions are φ30 mm * 10 mm, with a porosity of 83.5% and a density of 0.19 g / cm³. 3 .

[0048] Hydrostatic tests compared four configurations, including a traditional single-shell design and the three embodiments described above. The results showed that the average critical failure pressures for the four models were 0.64 MPa (single-shell), 1.59 MPa (single-layer biomimetic), 2.40 MPa (four-layer homogeneous), and 4.13 MPa (four-layer gradient), corresponding to equivalent diving depths of 64 m, 159 m, 240 m, and 413 m, respectively. Figure 4 ).

[0049] It is important to emphasize that, under the same density, the four-layer gradient model not only has the best pressure resistance, but also the actual load-bearing capacity of the four-layer gradient configuration is 6.45 times that of the traditional monolithic shell, which also shows that biomimetic design is a design with higher mechanical efficiency.

[0050] Example 4 The compression test of the biomimetic pressure-resistant cylinder based on cuttlebone provided in Example 3 was conducted under quasi-static compression conditions on a universal testing machine at a speed of 1 mm / min. Figure 5 As shown, the peak load capacity is 1.57 times that of steel pipes of similar diameter and weight, and nearly 4 times that of PVC pipes. At the same time, the unit strength at 5% strain is also better than both.

[0051] Application Example 1 Using the biomimetic pressure-resistant cylinder provided in Example 3 as the outer shell, the internal cavity can be used to load LED light sources, thus forming an underwater light source, such as... Figure 6 As shown, the constructed underwater light source can adjust its buoyancy according to the load to achieve neutral buoyancy, thus enabling constant-depth suspension. It can also be integrated as an external module into deep-sea submersibles for remote light source deployment. Furthermore, other equipment such as cameras and power supplies can also be housed within the chamber.

[0052] A 10 mm thick PMMA sheet was bonded using epoxy adhesive to allow the light source to pass through. The effect of pressure on the underwater light source's illumination performance was observed using an underwater camera.

[0053] The results show that the underwater light source maintained stable illumination performance before the cylinder in Example 3 ruptured, until the pressure-resistant cylinder ruptured under 450 m water pressure, causing water to enter the underwater light source and the LED to short-circuit and fail. Figure 7 ).

[0054] Furthermore, the continuous and independent multi-cavity system in this structure provides a novel technological approach for underwater pipeline transportation. Its main advantages include: 1) Significant buckling resistance: Maintaining structural stability even under high hydrostatic pressure is crucial for ensuring the safe operation of deep-sea equipment; 2) Support for efficient parallel transport of multiple media: The open-cavity structure facilitates the stable flow of multiphase media such as oil and gas-hydrates, while the non-interconnected nature of the cavities allows for the separate transport of different fluids, avoiding cross-contamination, making it particularly suitable for the efficient development and distributed transmission of seabed oil and gas resources; 3) Lightweight and high-strength structure: Thanks to its biomimetic porous design, the structure maintains high mechanical strength while possessing extremely low mass density, reducing material consumption and overall deployment costs without sacrificing pressure resistance. This design, integrating superior pressure resistance, material efficiency, and multifunctionality, not only provides an innovative solution for subsea pipeline systems but also demonstrates broad application prospects in engineering fields such as marine platform anchor chains and deep-sea probe shells, marking a significant breakthrough in deep-sea equipment technology.

Claims

1. A biomimetic pressure-resistant cylinder based on cuttlebone, characterized in that, The biomimetic pressure-resistant cylinder comprises, from the inside out, a central cylinder and several layers of concentric circular plates. Each layer has an inner wall, which is an asymmetrical S-shaped wave wall. The cavity formed by the layers and the asymmetrical S-shaped wave wall extends along the cylinder axis.

2. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 1, characterized in that, The biomimetic pressure-resistant cylinder has a porosity of 65-90%.

3. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 1, characterized in that, The inner walls of each layer are evenly distributed, and the inner walls of adjacent layers are staggered.

4. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 1, characterized in that, In two adjacent layers, the number of inner walls on the outer layer is twice that on the inner layer.

5. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 1, characterized in that, In two adjacent layers, the ratio of the inner layer height to the outer layer height is 0.9-1.

5.

6. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 5, characterized in that, The spacing between the layers has a gradient that increases from the outside in.

7. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 1, characterized in that, The biomimetic pressure-resistant cylinder comprises 1-4 layers of plates.

8. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 1, characterized in that, The density of the biomimetic cylinder is 0.15-1 g / cm³. 3 .

9. The biomimetic pressure-resistant cylinder based on cuttlebone according to claim 1, characterized in that, The biomimetic cylinder is prepared by 3D printing technology, which is selected from stereolithography (SLA), fused deposition modeling (FDM), digital light processing (DLP), two-photon polymerization (TPP), powder bed fusion (PBF), or laser selective sintering (SLS).

10. The application of the biomimetic pressure-resistant cylinder according to any one of claims 1-9 in underwater lighting modules, deep-sea unmanned underwater vehicle (AUV / ROV) hulls, transport pipelines, or buried pipelines.

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