Hollow glass bead doped silica gel based bionic flexible pectoral fin and preparation method and application thereof

Abstract

The invention discloses a hollow glass bead doped silica gel based bionic flexible pectoral fin and a preparation method and application thereof, and relates to the technical field of deep sea flexible buoyancy materials. The bionic flexible pectoral fin is prepared from, by mass, 5%-20% of hollow glass beads and 80%-91% of silica gel. The hollow glass beads are doped in the silica gel base, the flexible deformable pectoral fin which is light in weight and high in strength is prepared, active and passive large deformation is achieved while the underwater high-pressure resistance of the bionic pectoral fin is improved, and then the propulsive efficiency of the pectoral fin in the manta ray imitating submersible large-scale process is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of deep-sea flexible buoyancy materials, and in particular to a bionic flexible pectoral fin of hollow glass microspheres doped with silica gel, and a preparation method and application thereof. Background Art

[0002] With the rapid development of society, humanity's need to explore and develop marine resources has become increasingly urgent. To fully utilize these resources, various submersibles have been extensively developed and deployed. Traditional underwater vehicles offer advantages such as long range and low noise, but they suffer from low speed, weak anti-interference capabilities, and poor maneuverability. Compared to traditional underwater vehicles, bionic submersibles offer enhanced maneuverability, high stealth, and biocompatibility, representing a new generation of high-end autonomous underwater equipment.

[0003] Manta rays are large fish with both flapping and gliding abilities. Manta ray-inspired submersibles offer excellent swimming stability and serve as excellent payload platforms, capable of comprehensive capabilities such as wide-area, long-term monitoring, in-situ observations in complex terrain, and high-cover, close-range reconnaissance. To advance the practical application of manta ray-inspired submersibles and meet diverse mission requirements, future prototypes must include more cargo space to accommodate a variety of payload systems. Therefore, the increasing size of manta ray-inspired submersibles is an inevitable trend in their future development. However, as the size of each module increases, the mass of the bionic pectoral fins increases, significantly impacting their propulsion performance. Furthermore, the dramatic increase in water pressure required for deep-sea applications of large manta ray-inspired submersibles during operation places even higher demands on the bionic pectoral fins' strength and water absorption. Therefore, the development of bionic pectoral fin materials that are lightweight, high-strength, and low in water absorption is urgently needed. Currently, the main flexible and deformable materials used in deep-sea submersibles are carbon fiber reinforced plastic (CFRP) and glass fiber reinforced plastic (GFRP). Among them, CFRP has low density and high strength, but is expensive; GFRP is cheaper than CFRP, but has relatively low strength and poor wear resistance. Summary of the Invention

[0004] In response to the deficiencies in the above-mentioned background technology, the present invention provides a bionic flexible pectoral fin material and a preparation method thereof. The material is light in weight, high in strength, and low in cost, and can meet the deep-sea application requirements of large manta ray-like submersibles.

[0005] The present invention provides a bionic flexible pectoral fin of hollow glass microspheres doped with a silica gel matrix, and a preparation method and application thereof. The hollow glass microspheres used in the bionic flexible pectoral fin have the advantages of low density, high specific strength, high compression strength, good fluidity, good dispersibility, etc., and play an irreplaceable role in lightweight, high-strength, low-density composite materials, deep-sea buoyancy materials, etc. The "skin" of the bionic pectoral fin uses flexible deformable silica gel to cover the surface of the "fin ray" skeleton, which can effectively increase the interaction area between the rear edge of the pectoral fin and the water, enhance the passive deformation ability of the rear edge of the pectoral fin, and thus improve the propulsion efficiency. On this basis, hollow glass microspheres are doped in a silica gel matrix to prepare a lightweight, high-strength, flexible, deformable pectoral fin, which can achieve large active and passive deformation while improving the underwater high-pressure resistance of the bionic pectoral fin, thereby improving the propulsion efficiency of the pectoral fin during the large-scale development of the manta ray-like submersible.

[0006] The first purpose of the present invention is to provide a bionic flexible pectoral fin of hollow glass microspheres doped with silica gel. The bionic flexible pectoral fin raw material adopts the following components in mass fraction: 5-20% hollow glass microspheres, 80-91% silica gel, and a total of 100%.

[0007] Preferably, the hollow glass microspheres include borosilicate hollow glass microspheres and / or silicate hollow glass microspheres.

[0008] Preferably, the hollow glass microspheres have a diameter of 70-100 μm and a density of 0.2-0.6 g / cm 3 .

[0009] Preferably, the silica gel comprises silica gel A and silica gel B, wherein the density of silica gel A and silica gel B are both 1.015-1.2 g / cm 3 .

[0010] The second object of the present invention is to provide a method for preparing a hollow glass microsphere-doped silica gel-based biomimetic flexible pectoral fin, comprising the following steps: Stir liquid silicone A and liquid silicone B until all bubbles are exhausted; Add hollow glass microspheres to liquid silica gel A, mix well, then add liquid silica gel B and continue mixing to obtain a mixed liquid; Alternatively, hollow glass microspheres are added to liquid silica gel B, mixed evenly, and then liquid silica gel A is added and mixed evenly to obtain a mixed liquid; The mixed liquid is put into a mold imitating the pectoral fin of a manta ray and solidified at room temperature to obtain a bionic flexible pectoral fin composed of hollow glass microbeads doped with silicone.

[0011] Preferably, the mass ratio of the liquid silicone rubber A to the liquid silicone rubber B is 0.4-0.6:1.

[0012] Preferably, the room temperature curing time is 12 to 24 hours.

[0013] Preferably, the bubble exhaustion process, the mixed liquid obtaining process, and the room temperature curing process are all carried out in a vacuum environment.

[0014] The third object of the present invention is to provide a bionic flexible pectoral fin of hollow glass microspheres doped with silica gel for use in a manta ray-like submersible.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a biomimetic flexible pectoral fin containing hollow glass microspheres and a silica gel matrix, as well as its preparation method and application. The pectoral fin can be coated onto the surface of the fin ribs of a manta ray-like submersible. The addition of the hollow glass microspheres not only reduces the density of the silica gel matrix but also increases the overall underwater high-pressure strength of the pectoral fin. The result is a lightweight, high-strength, flexible, and deformable underwater biomimetic pectoral fin, enhancing the propulsion efficiency of the pectoral fin during the scale-up of manta ray-like submersibles.

[0016] The present invention incorporates hollow glass microspheres into silica gel to precisely control the density of the bionic pectoral fin to be close to 1g / cm 3 (density of water), thereby achieving static floating of the manta ray-like submersible on the water surface.

[0017] The present invention adds hollow glass microspheres into silica gel, which can effectively reduce the density of silica gel and improve the underwater compressive strength of silica gel, thereby producing a lightweight, high-strength, flexible and deformable bionic pectoral fin.

[0018] After hollow glass microbeads are added to silica gel in the present invention, the water absorption rate of the bionic pectoral fin is relatively low under all test conditions, all less than 0.15%; the water absorption rate does not exceed 0.15% in 1 hour under a hydrostatic pressure of 30MPa, meeting the deep-sea application requirements during the large-scale development of manta ray-like submersibles. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A manta ray-like submersible installed for Example 5; Figure 2 The original density is 1.02g / cm 3 The silica gel is doped with different densities (g / cm 3 ) and mass proportion (%) of hollow glass microspheres, the density change bar graph of bionic pectoral fin; Figure 3 The original density is 1.20g / cm 3 The silica gel is doped with different densities (g / cm 3 ) and mass proportion (%) of hollow glass microspheres, the density change bar graph of bionic pectoral fin; Figure 4 The graphs of water absorption of the bionic pectoral fin at 10MPa, 20MPa and 40MPa respectively as a function of hollow glass microsphere content; Figure 5 This is a schematic diagram of the main body of the manta ray-like submersible. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0021] The purpose of the present invention is to provide a bionic flexible pectoral fin with hollow glass microspheres doped with silica gel, and its preparation method and application. Hollow glass microspheres have the advantages of low density, high specific strength, high compressive strength, good fluidity, good dispersibility, etc., and play an irreplaceable role in lightweight, high-strength, low-density composite materials, deep-sea buoyancy materials, etc. The bionic pectoral fin "skin" uses flexible deformable silica gel to cover the surface of the "fin ray" skeleton, which can effectively increase the interaction area between the trailing edge of the pectoral fin and the water, enhance the passive deformation ability of the trailing edge of the pectoral fin, and thus improve the propulsion efficiency. On this basis, hollow glass microspheres are doped in a silica gel matrix to prepare lightweight, high-strength, flexible, deformable pectoral fins, which can achieve large active and passive deformations while improving the underwater high-pressure resistance of the bionic pectoral fins, thereby improving the propulsion efficiency of the pectoral fins during the large-scale development of manta ray-like submersibles.

[0022] In order to achieve the above objectives, the first aspect of the present invention provides a bionic flexible pectoral fin composed of hollow glass microspheres doped with silica gel. The bionic flexible pectoral fin raw material adopts the following components in mass fraction: 5-20% hollow glass microspheres and 80-91% silica gel, totaling 100%.

[0023] The pectoral fins provided by this invention can be coated onto the surface of the "fin ray" skeleton of a manta ray-like submersible. The inclusion of hollow glass microspheres not only reduces the density of the silica gel matrix but also increases the overall underwater high-pressure strength of the pectoral fins. The result is a lightweight, high-strength, flexible, and deformable underwater biomimetic pectoral fin, improving the propulsion efficiency of the pectoral fins during the scaling-up of manta ray-like submersibles.

[0024] Wherein, the hollow glass microspheres include borosilicate hollow glass microspheres and / or silicate hollow glass microspheres.

[0025] The hollow glass microspheres have a diameter of 70-100µm and a density of 0.2-0.6g / cm 3 .

[0026] The silica gel comprises silica gel A and silica gel B, wherein the density of silica gel A and silica gel B is 1.015-1.2 g / cm 3 .

[0027] A second aspect of the present invention provides a method for preparing a biomimetic flexible pectoral fin of hollow glass microspheres doped with silica gel, comprising the following steps: Stir liquid silicone A and liquid silicone B until all bubbles are exhausted; Add hollow glass microspheres to liquid silica gel A, mix well, then add liquid silica gel B and continue mixing to obtain a mixed liquid; Alternatively, hollow glass microspheres are added to liquid silica gel B, mixed evenly, and then liquid silica gel A is added and mixed evenly to obtain a mixed liquid; The mixed liquid is put into a mold imitating the pectoral fin of a manta ray and solidified at room temperature to obtain a bionic flexible pectoral fin composed of hollow glass microbeads doped with silicone.

[0028] Wherein, the mass ratio of the liquid silicone rubber A to the liquid silicone rubber B is 0.4-0.6:1.

[0029] The curing time at room temperature is 12~24h.

[0030] The bubble exhaust process, the mixed liquid obtaining process, and the room temperature curing process are all carried out in a vacuum environment.

[0031] In this method, hollow glass microspheres (HGMs) are premixed with liquid silica gel B (typically a low-viscosity component) to reduce microbead agglomeration and improve dispersibility. Liquid silica gel A (such as a crosslinker or high-viscosity component) is then added, and shear forces (such as stirring) are used to further uniformly disperse the microbeads, preventing them from floating or settling due to density differences. Theoretically, HGMs are uniformly embedded in the three-dimensional silica gel network as single particles, forming an "island-in-the-sea" structure with no noticeable agglomeration or porosity.

[0032] The hollow glass microspheres (HGMs) used in this invention have a density of 0.2–0.6 g / cm³, significantly lower than the 1.0–1.2 g / cm³ of silica gel. When mixed, the HGMs occupy the volume of the silica gel matrix, but contribute very little mass (volume displacement effect). Furthermore, HGMs are sealed hollow spheres filled with inert gas, preventing them from absorbing moisture or adding additional mass (closed-cell structure). These two factors contribute to a decrease in the density of the silica gel matrix after the addition of HGMs. Furthermore, the stress-dispersing and volumetric compression resistance of the HGMs enhance the overall high-pressure resistance of the pectoral fin underwater. The high compressive strength of the HGMs withstands external water pressure and evenly distributes stress through the silica gel matrix, avoiding localized stress concentrations. While silica gel itself is easily compressed by high pressure, the rigid hollow structure of the HGMs maintains volume stability and prevents overall collapse.

[0033] A third aspect of the present invention provides an application of a hollow glass microsphere-doped silica gel-based bionic flexible pectoral fin in a manta ray-like submersible.

[0034] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0035] Silicone A and Silicone B are produced by Smooth-On in the United States.

[0036] Example 1 (1) Preparation of a mixture of hollow glass microspheres and silica gel Liquid silicone A and liquid silicone B with a mass ratio of 0.4:1 were weighed and poured into two beakers respectively; liquid silicone A and liquid silicone B were stirred until all bubbles were exhausted; hollow glass microbeads accounting for 10% by mass were added to liquid silicone A and stirred until the mixture was evenly mixed; liquid silicone A and liquid silicone B doped with hollow glass microbeads were mixed and stirred until the mixture was evenly mixed. The above operations were all performed in a vacuum environment.

[0037] The density of the original silicone pectoral fin obtained by mixing liquid silicone A and liquid silicone B is 1.02g / cm 3 ; The density of hollow glass microspheres is 0.2g / cm 3 .

[0038] (2) Preparation of flexible and deformable bionic pectoral fins Using vacuum-assisted casting, a mixture of liquid silicone A and liquid silicone B doped with hollow glass microspheres was injected into a manta ray pectoral fin mold and cured at room temperature for 12 hours before being taken out.

[0039] Example 2 This embodiment is basically the same as embodiment 1, except that in this embodiment, the density of the hollow glass microspheres is 0.4 g / cm 3 .

[0040] Example 3 This embodiment is basically the same as embodiment 1, except that in this embodiment, the density of the hollow glass microspheres is 0.6 g / cm 3 .

[0041] Example 4 This embodiment is basically the same as Example 1, except that, in this embodiment, hollow glass microspheres accounting for 15% by weight are added to the liquid silica gel A.

[0042] Example 5 This embodiment is basically the same as embodiment 4, except that in this embodiment, the density of the hollow glass microspheres is 0.4 g / cm 3 .

[0043] Example 6 This embodiment is basically the same as embodiment 4, except that in this embodiment, the density of the hollow glass microspheres is 0.6 g / cm 3 .

[0044] Example 7 This embodiment is basically the same as embodiment 1, except that, in this embodiment, hollow glass microspheres accounting for 20% by weight are added to the liquid silica gel A.

[0045] Example 8 This embodiment is basically the same as embodiment 1, except that, in this embodiment, hollow glass microspheres accounting for 5% by weight are added to the liquid silica gel A.

[0046] Example 9 This embodiment is substantially the same as embodiment 1, except that, in this embodiment, hollow glass microspheres are not added to the liquid silica gel A.

[0047] Example 10 This embodiment is basically the same as embodiment 1, except that in this embodiment, the mass ratio of liquid silicone rubber A to liquid silicone rubber B is 0.6:1; wherein, the density of the original silicone pectoral fin obtained by mixing liquid silicone rubber A and liquid silicone rubber B is 1.02 g / cm 3 ; Example 11 This embodiment is basically the same as embodiment 10, except that in this embodiment, the density of the hollow glass microspheres is 0.4 g / cm 3 .

[0048] Example 12 This embodiment is basically the same as embodiment 10, except that in this embodiment, the density of the hollow glass microspheres is 0.6 g / cm 3 .

[0049] Example 13 This embodiment is basically the same as Example 10, except that, in this embodiment, hollow glass microspheres accounting for 20% by weight are added to the liquid silica gel A.

[0050] Example 14 This embodiment is basically the same as embodiment 13, except that in this embodiment, the density of the hollow glass microspheres is 0.4 g / cm 3 .

[0051] Example 15 This embodiment is basically the same as embodiment 13, except that in this embodiment, the density of the hollow glass microspheres is 0.6 g / cm 3 .

[0052] Example 16 This embodiment is basically the same as Example 1, except that, in this embodiment, the room temperature curing time of the vacuum-assisted casting method is 24 hours.

[0053] Example 17 See also Figure 5 As shown in the figure, hollow glass microbeads doped with silicone bionic pectoral fins were installed on both sides of the prototype body to form a complete manta ray submersible, and a pool test was carried out. The results are shown in the figure. Figure 1 The density of hollow glass microspheres doped with silica gel in the bionic pectoral fin is controlled at 1g / cm 3 Left and right, it can realize static floating on the water surface and propulsion by flapping the pectoral fins of the manta ray-like submersible.

[0054] In order to illustrate the relevant performances of the bionic pectoral fin provided by the present invention, it is described in conjunction with the accompanying drawings.

[0055] Figure 1 The manta ray-like submersible installed in Example 17 has hollow glass microbeads doped with silicone and flexible, deformable bionic pectoral fins on its left and right sides. Figure 1 On the left is a photo of a manta ray-like submersible floating statically on the water; Figure 1 On the right is a photo of a manta ray-like submersible switching from a surface floating state to a flapping motion mode. Figure 1 It can be seen that adding hollow glass microbeads to silicone can accurately control the density of the bionic pectoral fins to be close to the density of water, thereby realizing motion modes such as static floating on the water surface and pectoral fin flapping of the manta ray-like submersible, as well as switching between motion modes.

[0056] Figure 2 The original density of the samples provided in Examples 1 to 6 is 1.02 g / cm 3 The silica gel is doped with different densities (g / cm 3 ) and mass percentage (%) of hollow glass microspheres, the density of the bionic pectoral fin changes. Figure 2 It can be clearly seen that the density of the bionic pectoral fins decreases with the decrease in the density of the hollow glass microbeads or the increase in the mass proportion, indicating that the addition of hollow glass microbeads into silica gel can effectively regulate the density of the bionic pectoral fins.

[0057] Figure 3 The original density of the samples provided in Examples 10 to 15 is 1.20 g / cm 3 The silica gel is doped with different densities (g / cm 3 ) and mass percentage (%) of hollow glass microspheres, the density of the bionic pectoral fin changes. Figure 3 It can be clearly seen that the density of the bionic pectoral fins decreases with the decrease in the density of the hollow glass microbeads or the increase in the mass proportion, which once again shows that the addition of hollow glass microbeads to silica gel can effectively regulate the density of the bionic pectoral fins.

[0058] Figure 4The water absorption rate of the bionic pectoral fins provided in Examples 1, 4 and 7-9 at 10 MPa, 20 MPa and 40 MPa respectively varies with the content of hollow glass microspheres. Figure 4 It is clearly evident that, at the same hydrostatic pressure, the water absorption rate of the biomimetic pectoral fin increases with the mass fraction (%) of the hollow glass microspheres. This is because as the hollow glass microsphere content increases, the density of the silicone matrix decreases; at the same time, the bond between the hollow glass microspheres and the silicone becomes less tight. Therefore, under high-pressure water, water molecules more easily penetrate the interior of the biomimetic pectoral fin, resulting in an increase in the water absorption rate of the biomimetic flexible pectoral fin material. Overall, however, the water absorption rate of the biomimetic pectoral fin remained below 0.15% at all tested pressures, meeting the requirements for deep-sea applications (≥1000 km) during the large-scale development of manta ray-like submersibles.

[0059] The present invention describes preferred embodiments and their effects. However, those skilled in the art, once informed of the basic inventive concept, may make additional changes and modifications to these embodiments. Therefore, it is intended that the appended claims be interpreted to include the preferred embodiments as well as all changes and modifications that fall within the scope of the invention.

[0060] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A bionic flexible pectoral fin of hollow glass microspheres doped with silica gel, characterized in that: The bionic flexible pectoral fin material adopts the following components in mass fraction: 5-20% hollow glass microspheres, 80-91% silica gel, and a total of 100%.

2. The hollow glass microsphere-doped silica gel-based bionic flexible pectoral fin according to claim 1, characterized in that: The hollow glass microspheres include borosilicate hollow glass microspheres and / or silicate hollow glass microspheres.

3. The hollow glass microsphere-doped silica gel-based bionic flexible pectoral fin according to claim 1, characterized in that: The hollow glass microspheres have a diameter of 70-100µm and a density of 0.2-0.6g / cm 3 .

4. The hollow glass microsphere-doped silica gel-based bionic flexible pectoral fin according to claim 1, characterized in that: The silica gel comprises silica gel A and silica gel B, wherein the density of silica gel A and silica gel B is 1.015-1.2 g / cm 3 .

5. A method for preparing a biomimetic flexible pectoral fin of hollow glass microspheres doped with silica gel according to any one of claims 1 to 4, characterized in that: The following steps are involved: Stir liquid silicone A and liquid silicone B until all bubbles are exhausted; Add hollow glass microspheres to liquid silica gel A, mix well, then add liquid silica gel B and continue mixing to obtain a mixed liquid; Alternatively, hollow glass microspheres are added to liquid silica gel B, mixed evenly, and then liquid silica gel A is added and mixed evenly to obtain a mixed liquid; The mixed liquid is put into a mold imitating the pectoral fin of a manta ray and solidified at room temperature to obtain a bionic flexible pectoral fin composed of hollow glass microbeads doped with silicone.

6. The method for preparing the hollow glass microsphere-doped silica gel-based bionic flexible pectoral fin according to claim 5, characterized in that: The mass ratio of the liquid silicone rubber A to the liquid silicone rubber B is 0.4-0.6:

1.

7. The method for preparing the hollow glass microsphere-doped silica gel-based bionic flexible pectoral fin according to claim 5, characterized in that: The curing time at room temperature is 12~24h.

8. The method for preparing the hollow glass microsphere-doped silica gel-based biomimetic flexible pectoral fin according to claim 5, characterized in that: The bubble exhaust process, the mixed liquid obtaining process, and the room temperature curing process are all carried out in a vacuum environment.

9. Use of the hollow glass microspheres doped with silica gel as claimed in any one of claims 1 to 4 in a manta ray-like submersible.

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