Bionic coupled texture inspired by fish scale and phyllotaxis and its design method and application

Abstract

This invention discloses a biomimetic coupled texture inspired by both fish scales and foliage, along with its design method and application. The biomimetic coupled texture comprises multiple fish scale structural units arranged in a 137.508° golden spiral pattern resembling plant foliage. The fish scale structural units in each layer form a circumferential array, satisfying the polar coordinate equations ρ=ds, φ=n*α, and H=n*h, where: ds is the radius of the foliage base circle, n is the ordinal number of the fish scale structural unit, α is the angle between the nth and (n+1)th fish scale structural units (α=137.508°), and h is the distance between two adjacent fish scale structural units along the column direction. Its significant advantage is that the above scheme, by referencing the shape of fish scales to design the friction pattern and considering leaf arrangement, achieves friction-thermal performance optimization through a complete process of parametric modeling, friction-thermal coupling simulation, multi-objective optimization screening, and experimental verification.

Description

Technical Field

[0001] This invention relates to the field of biomimetic coupled texture technology, specifically to a fish-scale-leaf sequence dual-inspired biomimetic coupled texture and its design method and application. Background Technology

[0002] Friction and wear are common problems in mechanical systems. Statistics show that approximately 50% of failures and 30% of energy losses worldwide originate from friction and wear. Traditional surface treatment technologies often focus on optimizing a single performance aspect, making it difficult to achieve synergistic coordination between friction and temperature control. However, biological organisms in nature have evolved multi-level structures that balance drag reduction, wear resistance, and heat dissipation. For example, the interlocking arrangement of fish scales weakens adhesion vortices, and plant leaf arrangement conforms to a 137.5° golden spiral to optimize ventilation and light penetration, providing inspiration for biomimetic structural design. However, existing research often focuses on single-factor morphology or single operating conditions, lacking a systematic multi-scale parameter framework and mechanistic quantification. Furthermore, it suffers from problems such as a disconnect between simulation and experiment, and low optimization efficiency. For example:

[0003] Single biomimetic texture design technology: By mimicking the microstructure of shark skin, a rhomboid biomimetic texture is designed and applied to gear-rack mechanisms to improve tribological performance under insufficient lubrication conditions. [1] Alternatively, a double-layered double-helix concrete structure based on the double-helix structure of coelacanth scales can be fabricated to improve fracture toughness. [2] This type of technology typically selects a single biological structure as a biomimetic prototype, determines a single-dimensional texture parameter, and fabricates it on the surface of mechanical parts through methods such as laser processing, then tests its tribological properties experimentally. However, this type of technology only focuses on single-factor morphology design, without constructing a multi-scale parameter framework, and cannot comprehensively consider the coupled effects of multiple factors, making it difficult to achieve comprehensive optimization of friction-thermal performance. In addition, this type of technology is mostly designed for single working conditions, such as insufficient lubrication, and lacks system adaptability to both dry and wet typical working conditions, limiting its application scenarios. At the same time, this type of technology has not established a systematic "simulation optimization-experimental verification" process, resulting in many repetitive experiments during the research and development process, high research and development costs, long cycles, and difficulty in accurately quantifying the correlation mechanism between structure and performance.

[0004] Traditional tribo-thermal optimization techniques improve the friction, wear, and heat dissipation performance of mechanical components through surface coatings or simple texturing. For example, laser cladding of a 316L / dual-scale SiC composite coating can optimize tribo-wear performance. [3] Or improve engine friction performance through different textures. [4]This type of technology typically involves determining the parameters of a specific coating material or texture and then experimentally testing its frictional performance. However, it fails to draw inspiration from the multi-level optimization structures of organisms in nature, resulting in a lack of targeted design and difficulty in achieving a synergistic improvement in friction reduction and heat dissipation. Furthermore, this technology is poorly adapted to the friction-thermal coupling problem under high-speed, heavy-load conditions, and cannot effectively reduce the combined negative impacts of friction coefficient, wear rate, and temperature rise, making it difficult to meet the performance requirements of high-end mechanical components.

[0005] [1]Zhang, L.; Chen, Q.; Yin, Y.; Song, H.; Tang, J. Effects and optimization of bionic texture parameters on the tribological behavior ofline contacts under starved lubrication conditions. Industrial Lubricationand Tribology 2024, 76, 241–251.

[0006] [2]Prihar, A.; Gupta, S.; Esmaeeli, HS; Moini, R. Tough double-bouligand architected concrete enabled by robotic additive manufacturing. Nature communications 2024, 15, 7498.]

[0007] [3] Ruan Wenlian, Zhang Jianrun, Jiao Renqiang. Methods for improving engine lubrication and friction performance based on different concave textures (English) [J]. Journal of Southeast University (English Edition), 2021, 37(04): 365-371.

[0008] [4] Li Pengyu, Dong Hui, Zhang Yongjie, et al. Structure and tribological properties of laser-clad 316L / dual-scale SiC composite coating [J]. Heat Treatment of Metals, 2025, 50(09):39-47. DOI:10.13251 / j.issn.0254-6051.2025.09.007.

[0009] To address the aforementioned issues, this application develops a multi-parameter collaborative optimization biomimetic texture design method to achieve a comprehensive improvement in friction-thermal performance, meet the application requirements of high-speed heavy-duty machinery, and provide theoretical and engineering support for high-end bearings, brake pads, and aerospace rotors. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the purpose of this invention is to provide a biomimetic coupled texture inspired by fish scales and leaf arrangement, along with its design method and application. By drawing inspiration from the shape of fish scales to design friction pattern shapes and referencing leaf arrangement, the invention achieves friction-thermal performance optimization through a complete process of parametric modeling, friction-thermal coupling simulation, multi-objective optimization screening, and experimental verification.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] In a first aspect, the present invention provides a biomimetic coupled texture inspired by both fish scale and foliage, the key of which is: it includes multiple fish scale structural units, which are arranged in a 137.508° golden spiral following the foliage pattern of plants. The fish scale structural units in each layer form a circumferential array, satisfying the polar coordinate equations ρ=ds, φ=n*α, H=n*h, where: ds is the radius of the foliage base circle, n is the ordinal number of the fish scale structural unit, α is the angle between the nth and (n+1)th fish scale structural units, α=137.508°, and h is the distance between two adjacent fish scale structural units along the column direction.

[0013] Furthermore, the number of layers after arranging the multiple fish scale structural units is 1 to 4.

[0014] Furthermore, the number of fish-scale structure units in each of the circumferential arrays is 12 to 28.

[0015] Furthermore, the misalignment angle between two adjacent layers of the circumferential array is 1 / 2α.

[0016] Furthermore, the arc length of the fish scale structure unit is 0.8~1.6mm.

[0017] Furthermore, the exposed arc surface of the fish scale structure unit adopts a three-centered circular curve with a width-to-height ratio of 2:1 and an inclination angle of 45°.

[0018] In a second aspect, the present invention provides a design method for a biomimetic coupled texture inspired by the fish scale-foliage dual-inspiration method as described in the first aspect, comprising the following steps:

[0019] Step 1: Use drafting software to perform parametric modeling of the biomimetic coupled texture;

[0020] Step 2: Using the COMSOL software, establish a linear elastic contact model and perform friction-thermal coupling simulation.

[0021] Step 3: Process the simulation data using the entropy-linear weighting method, and combine it with orthogonal experiments to analyze the influence of each parameter and determine several optimal parameter combination schemes;

[0022] Step 4: Based on multiple optimal parameter combinations, prepare multiple test samples and conduct friction experiments and dry and wet condition tests;

[0023] Step 5: Determine the optimal parameter combination scheme based on the results of friction experiments and dry and wet working condition tests.

[0024] Furthermore, in step 4, experimental samples are prepared using photopolymerization 3D printing technology, laser processing technology, and mechanical engraving technology.

[0025] Furthermore, in step 4, a friction tester is used to conduct friction experiments, and a pin-disc testing machine is used to conduct dry and wet condition tests.

[0026] Thirdly, the present invention provides an application of the fish scale-leaf sequence dual-inspired biomimetic coupling texture as described in the first aspect in high-speed heavy-duty mechanical components.

[0027] The significant effects of this invention are:

[0028] 1. Multi-factor coupled optimization, significantly improving overall performance: This invention achieves multi-factor synergistic optimization by constructing a four-dimensional parameter matrix of "circumferential quantity-scale-hierarchy-dislocation". Under the optimal parameter combination, the friction coefficient decreases by 11.7% in dry friction, the wear depth decreases by 54.4%, and the temperature rise decreases by 36.7%; under wet friction, the friction coefficient is as low as 0.098, and the wear depth and temperature rise are reduced by 60.2% and 29.1% respectively, effectively solving the problem of incomplete performance optimization in existing technologies.

[0029] 2. Adaptable to multiple working conditions and wide range of applications: Through system testing and optimization under both dry and wet working conditions, the texture of this invention exhibits excellent performance under different friction environments. It can be widely used in a variety of high-speed heavy-duty mechanical components such as high-end bearings, brake pads, and aerospace rotors, overcoming the shortcomings of existing technologies that are only adaptable to a single working condition.

[0030] 2. High R&D efficiency and low cost: This invention establishes a collaborative process of "simulation optimization-experimental verification" and uses COMSOL simulation to initially screen the optimal solution, reducing the number of repeated experiments. The simulation and experimental error is less than 10%, the model has high reliability, significantly shortens the R&D cycle, reduces R&D costs, and solves the problem of traditional technology relying on experience and trial and error.

[0031] 2. Clear mechanism and strong reproducibility: This invention clearly defines the dominant load dispersion and oil film maintenance by the texture scale, and adopts the "wear reduction-heat dissipation" synergistic mechanism of multi-level eddies induced by misaligned layers and thermal channels. The proposed design method and parameter framework can be replicated and applied to the biomimetic texture design of other mechanical parts, and has important engineering promotion value. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the biomimetic coupling texture described in this invention;

[0033] Figure 2 This is a schematic diagram of the fish scale structure unit body described in this invention;

[0034] Figure 3 This is a biomimetic biological prototype diagram of the biomimetic coupling texture described in this invention;

[0035] Figure 4 This is a schematic diagram of 3*3*4 samples modeled by this invention;

[0036] Figure 5 These are images of 11 samples observed under an optical microscope before any friction was applied.

[0037] Figure 6 This is an image showing the results of observing 11 samples after dry rubbing using an optical microscope.

[0038] Figure 7 This is an image showing the results of observing 11 samples after wet rubbing using an optical microscope. Detailed Implementation

[0039] The specific embodiments and working principles of the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] Example:

[0041] Definitions of abbreviations and key terms in this embodiment

[0042] COMSOL COMSOL Multiphysics Multiphysics simulation software STL Stereolithography Stereolithography file format μ Friction Coefficient coefficient of friction α Spiral Angle of Phyllotaxis Leaf spiral angle N Number of Patterns per Circle Number of patterns per circle S Scale Arc Length Scale arc length scale L Number of Layers Number of layers X Displacement Parameter Misaligned parameters

[0043] Over long periods of evolution, organisms in nature have developed multi-level structures that balance drag reduction, wear resistance, and heat dissipation. For example, the interlaced arrangement of fish scales can weaken attachment vortices, and the foliage arrangement of plants conforms to a 137.5° golden spiral to optimize ventilation and light penetration, providing inspiration for biomimetic structural design. However, existing research often focuses on single-factor morphology or single operating conditions, lacking a systematic multi-scale parameter framework and mechanistic quantification, and suffers from problems such as a disconnect between simulation and experiment, and low optimization efficiency. Therefore, this embodiment proposes a biomimetic coupled texture inspired by both fish scales and foliage arrangement, along with its design method and application, to address the following technical problems:

[0044] 1. To address the problem that existing single biomimetic morphology texture design technologies do not consider the coupling effects of multiple factors and cannot achieve comprehensive optimization of friction-thermal performance;

[0045] 2. Overcome the shortcomings of existing technologies that are only suitable for a single working condition and have limited application scenarios, and achieve simultaneous improvement of the tribological performance of mechanical components under two typical working conditions: dry and wet.

[0046] 3. To address the problems of repetitive experiments, high costs, and long cycles in traditional technology research and development, establish a precise and efficient multi-scale collaborative design process of "parameter-mechanism-performance";

[0047] 4. Improve the wear resistance and heat dissipation performance of high-speed heavy-duty mechanical components, reduce friction and wear and energy loss, extend equipment life and improve energy efficiency.

[0048] like Figures 1-3 As shown, this embodiment of the invention provides a biomimetic coupled texture inspired by fish scales and leaf arrangement. The biomimetic coupled texture mainly imitates fish scales and leaves commonly found in nature. It draws inspiration from the shape of fish scales to design the friction pattern shape and also refers to the arrangement of leaves to design a staggered pattern arrangement. Specifically, it includes multiple fish scale structural units 1. The exposed arc surface of the fish scale structural unit 1 adopts a three-centered circular curve with a width-to-height ratio of W0∶H0=2:1 and an inclination angle of 45° to facilitate the discharge of wear debris and the storage of lubricating oil.

[0049] Arrangement pattern: Multiple fish-scale structural units 1 follow the golden spiral arrangement of plant phyllotaxis at 137.508°. The fish-scale structural units 1 in each layer form a circumferential array, satisfying the polar coordinate equations ρ=ds, φ=n*α, H=n*h, where: ds is the radius of the base circle of the phyllotaxis, n is the ordinal number of the fish-scale structural unit 1, α represents the angle between two adjacent phyllotaxis points, which is the angle between the nth fish-scale structural unit 1 and the (n+1)th fish-scale structural unit 1, α=137.508°, and h is a coefficient that measures the sparseness of the phyllotaxis arrangement, which is the distance between two adjacent fish-scale structural units 1 along the column direction.

[0050] In this example, the number of layers after arranging the multiple fish scale structure units 1 is 1 to 4, the misalignment angle between two adjacent layers of the circumferential array is 1 / 2α, and the number of fish scale structure units 1 in each circumferential array is 12 to 28.

[0051] As a preferred embodiment, the arc length of the fish scale structure unit 1 is 0.8~1.6mm.

[0052] In this embodiment, the fish scale structure unit 1 is arranged on the sample surface in a leaf sequence. In order to obtain an optimal pattern, the number of patterns, pattern size, and number of arrangement layers (including staggered patterns) of the sample are distinguished as follows;

[0053] Parameter matrix construction: A parameter matrix containing 4 factors was constructed, including the number of patterns per ring N (15, 20, 25), scale arc length S (0.9, 1.2, 1.5 mm), number of layers L (1, 2, 3 layers), and misalignment parameter X (adjacent layers rotate at an angle of 1 / 2α or are arranged concentrically), resulting in a total of 36 parameter combinations. An additional sample without patterns was set up as a control.

[0054] Optimal parameters: The optimal combination is determined through multi-objective optimization.

[0055] This embodiment also proposes a design method for biomimetic coupled texture inspired by the fish scale-foliage dual inspiration described above, including the following steps:

[0056] Step 1, Parametric Modeling:

[0057] SolidWorks software was used to model 36 parameter combinations and control samples, generating 37 STL models. The models must ensure that the textured surface is flat and without tilt.

[0058] Step 2, Friction-Thermal Coupling Simulation:

[0059] The STL model was imported into COMSOL software to establish a linear elastic contact model. The sample material was set to steel, and the stiffness of the friction pin disk material was one order of magnitude lower than that of the sample. The specific material properties of the sample and the friction pin disk are shown in Table 1 below.

[0060] Table 1 Material properties of the sample and friction pin in COMSOL software friction and wear simulation.

[0061] property sample Friction pin plate Young's modulus (GPa) 210 10 Poisson's ratio 0.3 0.1 Density (kg / m3) 7850 2000

[0062] Wear depth is predicted based on Archard's wear law (Equation (1)), and temperature rise is calculated using transient heat transfer equation. The minimum mesh element is set to 0.05 mm to ensure an error of <2%.

[0063] (1)

[0064] Where V represents the wear volume (unit: m³); k represents the dimensionless wear coefficient, characterizing the effects of material pairing and environment (usually determined experimentally); L represents the normal load (unit: N); s represents the sliding distance (unit: m); and H represents the hardness of the softer material (unit: Pa, commonly Vickers hardness or Brinell hardness).

[0065] Step 3: Multi-objective optimization screening:

[0066] The entropy-linear weighting method was used to process the simulation data (wear depth, maximum wear depth, temperature rise).

[0067] First, the negative index (the smaller the value, the better the performance) is normalized using formula (2):

[0068] (2)

[0069] Then, the proportion of the i-th sample under the j-th indicator is calculated using formula (3):

[0070] (3)

[0071] The entropy value of the j-th index is calculated using formula (4):

[0072] (4)

[0073] The value of K is calculated using formula (5):

[0074] K=1 / ln(n) (5)

[0075] Where n is the number of samples, the coefficient of difference for the j-th indicator is calculated using the following formula (6):

[0076] (6)

[0077] The weights of the evaluation indicators are calculated using the following formula (7):

[0078] (7)

[0079] The overall score is then calculated using a linear weighting method (Formula (8)):

[0080] (8)

[0081] Finally, by combining orthogonal experiments to analyze the influence of each parameter, nine optimal parameter combination schemes were selected from 36 parameter combinations.

[0082] Step 4, Experimental Verification:

[0083] Using photopolymer 3D printing technology, several sets of experimental samples were first printed using the school's photopolymer printer. Nine sets of samples with optimal parameter combinations and control samples were prepared using photosensitive resin as the printing material. Figure 4As shown, samples with smooth, undamaged surfaces were selected for the experiment. The friction experiment was conducted using a laboratory tribometer. After the wear tester and sample were installed, the test force, friction torque, friction type, friction time, and set rotation speed needed to be input. The tribometer has a built-in thermometer for temperature measurement during the friction process. A 1mm diameter hole was drilled 3mm below the patterned surface of the sample to facilitate thermometer insertion.

[0084] After the experiment, the tribometer will output the friction coefficient, thermometer readings, and wear values ​​of the samples at different time steps. Dry and wet tests were conducted using a pin-disc testing machine: dry friction condition (test force 100N, rotation speed 200r / min, time 10min); wet friction condition (test force 180N, sample surface coated with lubricating oil, other parameters consistent with dry friction). During the tests, the friction coefficient, temperature rise, and wear depth were recorded. After the experiment, the wear morphology was observed using an optical microscope, and the oil film thickness was measured using a white light interferometer.

[0085] The results of optical microscopy observation of 11 samples before and after dry and wet friction are as follows: Figure 5 , Figure 6 as well as Figure 7 As shown.

[0086] Step 5: Determine the optimal parameter combination scheme based on the friction experiment and dry and wet working condition test results. Specifically, the number of patterns per circle is N=20, the scale arc length is S=1.5mm, the number of layers is three, and the misalignment parameter x is 1 / 2α, denoted as 1-20-1.5-x.

[0087] It should be noted that in step 2, in addition to COMSOL software, other software with multiphysics coupling simulation capabilities such as ANSYS can be used to establish a friction-thermal coupling model. By adjusting simulation parameters (such as mesh generation accuracy and boundary condition settings), the reliability of the simulation results can be ensured, thereby completing parameter selection. In step 3, in addition to the entropy-linear weighted method, other multi-objective optimization algorithms such as genetic algorithms and particle swarm optimization algorithms can be used to process the simulation data and select the optimal texture scheme, which can also achieve comprehensive optimization of friction coefficient, wear rate, and temperature rise. In step 4, in addition to photopolymerization 3D printing, biomimetic coupled textures can be prepared by laser processing, mechanical engraving, etc. Laser processing is suitable for metal material parts, while mechanical engraving is suitable for ceramic matrix composite parts with high hardness, both of which can achieve the same texture structure and performance.

[0088] In summary, this invention employs a fish-scale-leaf sequence dual biomimetic coupling structure design to construct a four-dimensional parameter matrix of circumferential quantity, scale, hierarchy, and misalignment, achieving multi-factor synergistic control. Simultaneously, through a multi-scale synergistic design framework of parameters, mechanisms, and performance, combined with COMSOL friction-thermal coupling simulation and entropy-orthogonal experimental multi-objective optimization, the optimal parameter combination scheme is precisely selected. Finally, through the "friction reduction-heat dissipation" synergistic mechanism induced by texture scale and misalignment hierarchy, the influence of each parameter on friction-thermal performance is clarified.

[0089] Therefore, the design method of the biomimetic coupled texture proposed in this invention includes a complete process of parametric modeling, friction-thermal coupling simulation, multi-objective optimization screening and experimental verification. The biomimetic coupled texture obtained by the design can be applied to high-speed heavy-duty mechanical components (such as bearings, brake pads, aircraft rotors, etc.), and has achieved the technical effect of improving friction-thermal performance under both dry and wet conditions.

[0090] The technical solution provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A biomimetic coupled texture inspired by both fish scales and foliage, characterized in that: It includes multiple fish-scale structural units, which are arranged in a 137.508° golden spiral according to the phyllotaxis of plants. The fish-scale structural units in each layer form a circumferential array, satisfying the polar coordinate equations ρ=ds, φ=n*α, H=n*h, where: ds is the radius of the base circle of the phyllotaxis, n is the ordinal number of the fish-scale structural unit, α is the angle between the nth and (n+1)th fish-scale structural units, α=137.508°, and h is the distance between two adjacent fish-scale structural units along the column direction.

2. The biomimetic coupling texture inspired by both fish scales and foliage as described in claim 1, characterized in that: The number of layers after arranging multiple fish scale structural units is 1 to 4.

3. The biomimetic coupling texture inspired by both fish scales and foliage as described in claim 1, characterized in that: The number of fish-scale structure units in each of the aforementioned circumferential arrays is 12 to 28.

4. The biomimetic coupling texture inspired by both fish scales and foliage as described in claim 1, characterized in that: The misalignment angle between two adjacent layers of the circumferential array is 1 / 2α.

5. The biomimetic coupling texture inspired by the fish scale-foliage dual-inspiration method according to any one of claims 1-4, characterized in that: The arc length of the fish scale structure unit is 0.8~1.6mm.

6. The biomimetic coupled texture inspired by the fish scale-foliage dual-inspiration method according to any one of claims 1-4, characterized in that: The exposed arc surface of the fish scale structure unit adopts a three-centered circular curve with a width-to-height ratio of 2:1 and an inclination angle of 45°.

7. A design method for a biomimetic coupled texture inspired by fish scales and foliage as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Use drafting software to perform parametric modeling of the biomimetic coupled texture; Step 2: Using the COMSOL software, establish a linear elastic contact model and perform friction-thermal coupling simulation. Step 3: Process the simulation data using the entropy-linear weighting method, and combine it with orthogonal experiments to analyze the influence of each parameter and determine several optimal parameter combination schemes; Step 4: Based on multiple optimal parameter combinations, prepare multiple test samples and conduct friction experiments and dry and wet condition tests; Step 5: Determine the optimal parameter combination scheme based on the results of friction experiments and dry and wet working condition tests.

8. The design method for biomimetic coupled texture inspired by fish scales and foliage as described in claim 7, characterized in that, In step 4, experimental samples are prepared using photopolymerization 3D printing technology, laser processing technology, and mechanical engraving technology.

9. The design method for biomimetic coupled texture inspired by fish scales and foliage as described in claim 7, characterized in that, In step 4, a friction tester is used to conduct friction experiments, and a pin-disc testing machine is used to conduct dry and wet condition tests.

10. The application of a fish-scale-leaf sequence dual-inspired biomimetic coupling texture as described in any one of claims 1-6 in high-speed heavy-duty mechanical components.

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