Method for obstacle avoidance by fusing bubbles split by super-hydrophobic tracks

Abstract

The application discloses a method for realizing obstacle avoidance by using super-hydrophobic track to split and then fuse bubbles. The Y-shaped central symmetry structure of the super-hydrophobic track and the same width and distance of the two branch tracks are used to realize the highly symmetrical splitting and fixed-point fusion of the bubbles; and the shape and distance of the left and right branches are changed to avoid obstacles. The application has the advantages of simple preparation, low cost, no need of external energy driving, realization of highly symmetrical splitting and fixed-point fusion regulation of the bubbles under the action of buoyancy and adhesion, and the like. The application can design corresponding tracks according to the shape of the obstacles to realize flexible obstacle avoidance of the bubbles in a limited height closed space. The application can change the size of the split bubbles by changing the initial bubble diameter.

Description

Technical Field

[0001] This invention belongs to the field of multiphase flow technology, specifically relating to a method for obstacle avoidance by using superhydrophobic orbits to split bubbles at fixed points and then merge them. Background Technology

[0002] Precise control of underwater bubbles is fundamental to bubble micromixing reactors. Although bubble splitting and fusion are widespread in many industrial processes such as mineral flotation, heat exchange systems, and mixing reactors, accurately controlling the size of bubble splitting and the timing of fusion remains a challenge. Current research mainly focuses on the directional transport and fusion of bubbles, with few studies focusing on manipulating the size of bubble splitting and the targeted fusion of sub-bubbles.

[0003] Bubbles split into multiple sub-bubbles, which have relatively large specific surface areas. This increases the contact area between the bubbles and reactants in physical / chemical reactions, effectively improving system heat transfer and reaction efficiency. Furthermore, the point-to-point splitting and merging of bubbles increases the movement path of numerous sub-bubbles in the liquid phase, effectively promoting mineral flotation. However, existing methods for on-demand bubble splitting and merging mainly rely on microchannel structures. Microchannel fabrication is complex, and this method requires energy input, making it prone to residue or contamination. Moreover, due to the high surface tension of water, even symmetrical branching of microchannels in microfluidic chips struggles to achieve symmetrical bubble splitting. Patterned superhydrophobic tracks for bubble manipulation are a current research hotspot and a potential solution to this problem. Superhydrophobic surfaces exhibit strong wall-normal adhesion to bubbles in water and are widely used in underwater bubble control.

[0004] In summary, the control of bubble splitting size and pinpoint fusion is crucial for many of the aforementioned industrial processes. Designing a superhydrophobic track could enable precise control of bubble splitting size and pinpoint fusion to avoid obstacles, overcoming the limitations of microchannel methods. This would allow even bubbles much larger than a confined space with obstacles to spontaneously and cleverly pass through obstacles without significant velocity decay during splitting, without external force or energy input. Furthermore, multiple sub-bubbles splitting through this track could directionally transport different reactants, catalysts, etc., without energy consumption, providing new ideas for technological innovation in fields such as bioengineering and fine chemistry. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a superhydrophobic orbit for obstacle avoidance and a corresponding obstacle avoidance method.

[0006] In one aspect, the present invention provides a superhydrophobic track that enables bubbles to split at a fixed point and then merge to achieve obstacle avoidance.

[0007] The superhydrophobic track is located on a planar substrate and includes an upstream main track, a downstream main track, a left branch track, and a right branch track;

[0008] The upstream main track splits symmetrically into a left branch track and a right branch track in a Y-shape, with the split point located at the top of the upstream main track;

[0009] The downstream main track branches into an inverted Y-shape, merging the left and right branch tracks at the starting point of the downstream main track.

[0010] The bubble moves in a straight line along the upstream main track and splits at the split point. The bubble is divided into two sub-bubbles of equal size. Each sub-bubble moves in a direction according to the preset left and right branch shapes to avoid obstacles. After passing through the inverted Y-shaped fork structure, it reaches the confluence point, merges into a single bubble, and enters the downstream main track.

[0011] Secondly, the present invention provides a method for obstacle avoidance by using superhydrophobic orbits to split bubbles at fixed points and then merge them.

[0012] The superhydrophobic Y-shaped centrally symmetric structure and the fact that the width and path of the two branch tracks are the same are used to achieve symmetrical splitting and fixed-point fusion of bubbles at height;

[0013] By changing the shape and length of the left and right side roads, obstacles can be avoided.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] (1) The present invention is simple to prepare, low in cost, and does not require external energy drive. It achieves highly symmetrical splitting and fixed-point fusion control of bubbles only under the action of buoyancy and adhesion.

[0016] (2) The present invention can design corresponding tracks according to the shape of obstacles to realize flexible obstacle avoidance of bubbles in a closed space with a limited height.

[0017] (3) The present invention can change the size of the bubble after splitting by changing the initial bubble diameter. Attached Figure Description

[0018] Figure 1 A schematic diagram of superhydrophobic orbits with various bifurcated and converging shapes for obstacle avoidance.

[0019] Figure 2 This diagram illustrates the process of bubbles splitting and merging on bifurcated and converging superhydrophobic orbits during actual experiments.

[0020] Figure 3 A schematic diagram and process diagram of obstacle avoidance in a narrow cave on a superhydrophobic orbit.

[0021] Figure 4This is a schematic diagram of a Y-shaped symmetrical superhydrophobic orbital structure and a diagram of the bubble detachment process during an actual experiment.

[0022] Figure 5 This is a comparison diagram of the volumes of the left and right branches of the bubble after it splits.

[0023] In the diagram: 1. Downstream main track; 2. Left branch track; 3. Obstacle; 4. Right branch track; 5. Upstream main track; 6. Planar base. Detailed Implementation

[0024] This invention provides a technical solution for induced bubble point symmetrical splitting and fusion to avoid obstacles without energy input. It utilizes a superhydrophobic Y-shaped central symmetric structure and two branch track widths and distances of equal length to achieve highly symmetrical splitting and point fusion of bubbles. By changing the shape and distance of the left and right branches, obstacles in various situations can be avoided.

[0025] This invention designs and fabricates on a planar substrate, where, except for the superhydrophobic orbital region, the other planar regions of the substrate are nonhydrophobic surfaces. The microstructure of the prepared superhydrophobic orbital coating is controlled at the submicron level, so that the thickness of the attached air layer is also on the same order of magnitude.

[0026] The bifurcation and merging track consists of a downstream main track, an upstream main track, a left branch track, and a right branch track. The upstream main track splits into left and right branches in a Y-shape, with the split point located at the top of the upstream main track. The downstream main track bifurcates into an inverted Y-shape, merging the two branches at the starting point of the downstream main track. The left and right branch tracks have equal width and the same length, but their shapes may differ.

[0027] The bubble can split on the superhydrophobic track and avoid obstacles as needed by changing the shape of the left and right branches. The bubble moves in a straight line along the upstream main track and splits at the split point. The bubble is divided into two sub-bubbles of equal size. Each sub-bubble moves in a direction according to the preset left and right branch shape to avoid obstacles and reaches the confluence point through the inverted Y-shaped bifurcation structure. The two branch sub-bubbles merge and merge into one bubble step by step before entering the downstream main track.

[0028] Since the height of the split sub-bubbles in the normal wall direction is less than that of the initial bubble in the normal wall direction, the large bubble can achieve fixed-point obstacle avoidance by designing a bifurcated merging track. When the initial bubble is too large to pass through the gap with obstacles quickly, it can split into smaller bubbles by using the bifurcated merging track to enter the gap. The smaller bubbles will move in a directional manner according to the designed left and right branches, pass through the obstacles, and reach the merging point to merge into a single bubble. During the obstacle avoidance process, the smaller volume of the sub-bubbles can ensure that the speed of the bubbles does not change significantly.

[0029] In this invention, the width of the left and right branch tracks is the same, thus ensuring that the size of the split bubbles is the same, and the distance of the left and right branch tracks is the same, thus ensuring that the sub-bubbles arrive at the merging point at the same time for fixed-point fusion. The shapes of the left and right branch tracks do not need to be the same, as long as the Y-shaped structure is centrally symmetrical.

[0030] The bubble can avoid obstacles as needed by changing the bifurcation angle θ of the bifurcation and merging track and the distance and shape of the left and right branches; without changing the width of the branch track, the size of the bubble after splitting can be adjusted by changing the initial bubble diameter.

[0031] The left and right branch tracks and the main track can be in the shape of broken lines, arcs, etc.;

[0032] The Y-shaped structure at the splitting and merging points is a centrally symmetric structure.

[0033] The fluid can be a Newtonian or a non-Newtonian fluid;

[0034] The superhydrophobic substrate wall can be made of glass, metal, acrylic, or other engineering materials.

[0035] This embodiment:

[0036] In this embodiment, a glass plate is used as the substrate, and a layer of superhydrophobic coating is sprayed on it with a contact angle of 160°. The boundaries of the superhydrophobic track are etched using CNC engraving technology. The superhydrophobic track consists of a downstream main track 1, a left branch track 2, a right branch track 4, and an upstream main track 5, with an obstacle 3 in the middle. The superhydrophobic track width is set to 2mm, with a bifurcation angle θ of 40°. The Y-shaped symmetrical structure is centrally symmetrical, and the shapes of the left and right branches can be different, including straight lines, arcs, and apple shapes, etc. A schematic diagram is shown below. Figure 1 As shown.

[0037] When the superhydrophobic orbitals are submerged in water, the bubble floats freely upwards under the influence of buoyancy. Due to the superaerophilicity of the superhydrophobic orbitals, the bubble moves in a straight line along the upstream main orbital under the combined effects of buoyancy and the adhesive force of the superhydrophobic orbitals. When the bubble reaches the splitting point, the initial dynamic contact line of the bubble's front end undergoes strong symmetrical bending due to the high symmetry of the Y-shaped orbital width. Shortly afterward, the dynamic contact line of the rear end also bends in a similar manner. When the combined effects of the orbital adhesion, capillary force, and buoyancy completely overcome the bubble's surface tension, the two dynamic contact lines are broken, and the bubble splits at a fixed point into two sub-bubbles of similar size.

[0038] The sub-bubbles then move directionally along left and right branch paths designed to avoid obstacles. After traveling a certain distance along these pre-defined paths, they avoid obstacles and then reach the confluence point via an inverted Y-shaped fork structure. At the confluence point, the bubbles merge into a single bubble and enter the downstream main track. Because the splitting causes the height of the sub-bubbles in the normal wall direction to be less than the height of the initial bubble in the normal wall direction, various left and right branch path patterns were designed for agile obstacle avoidance. Actual experiments show... Figure 2 As shown, when the initial bubble is too large to pass through the slits, the bifurcation and merging track can first divide the initial bubble into two smaller, identical sub-bubbles at the split point, allowing them to spontaneously pass through the slits even with obstacles. Furthermore, the bubble's speed does not significantly decrease during the obstacle avoidance process. The shapes of the left and right branch tracks do not need to be identical; only central symmetry at the Y-shaped structure is required. The sub-bubbles simultaneously reach the merging point of the track along the two different-shaped but identical branches, re-merging into a single bubble that enters the downstream main track. This demonstrates that even if the bubble is much larger than the enclosed space with obstacles, it can flexibly and cleverly pass through obstacles by designing the branch shapes and routes without external force or energy and without changing the bubble's speed throughout the process. Figure 3 As shown.

[0039] Furthermore, to further demonstrate the high symmetry of the bubbles generated by the splitting of the track, a Y-shaped symmetrical track with straight left and right branches was constructed in this example, as shown below. Figure 4 As shown, the superhydrophobic orbital has a width of 2 mm and a bifurcation angle θ of 40°. Two equal-sized sub-bubbles are obtained through splitting. The superhydrophobic orbital substrate is a TPU film covering a glass plate, which is then sprayed with a superhydrophobic coating to construct a superhydrophobic surface. After the bubble splits along the orbital, it is guided away from the orbital by two "pointed" TPU films. Quantitative analysis verifies that the size and height of the split sub-bubbles are consistent. Figure 5 As shown in the figure, the experiment verified that the volume of the split bubble is the same under the same orbital width for the left and right branches.

[0040] In summary, the present invention is simple to prepare, low in cost, requires no energy input to regulate the height of bubble splitting and fixed-point splitting and fusion, and can change the shape and path of the left and right branches according to different obstacles to achieve flexible obstacle avoidance of the bubble in a confined space with limited height.

Claims

1. A superhydrophobic orbit that induces bubble splitting and re-fusion at a fixed point to achieve obstacle avoidance, characterized in that: The superhydrophobic track is located on a planar substrate and includes an upstream main track, a downstream main track, a left branch track, and a right branch track; The upstream main track splits symmetrically into a left branch track and a right branch track in a Y-shape, with the split point located at the top of the upstream main track; The downstream main track branches into an inverted Y-shape, merging the left and right branch tracks at the starting point of the downstream main track. The bubble moves in a straight line along the upstream main track and splits at the split point. The bubble is divided into two sub-bubbles of equal size. Each sub-bubble moves in a direction according to the preset left and right branch shapes to avoid obstacles. After passing through the inverted Y-shaped fork structure, it reaches the confluence point, merges into a single bubble, and enters the downstream main track. The left and right branch tracks have the same width and the same distance. The shapes of the left and right branch tracks are matched with the obstacles.

2. A method for obstacle avoidance using superhydrophobic orbits to split bubbles at specific points and then fuse them together, employing the superhydrophobic orbits described in claim 1, characterized in that: The superhydrophobic Y-shaped centrally symmetric structure and the fact that the width and path of the two branch tracks are the same are used to achieve symmetrical splitting and fixed-point fusion of bubbles at height; By changing the shape and length of the left and right side roads, obstacles can be avoided; The left and right branch tracks have the same width to ensure that the split bubbles are the same size. The left and right branch tracks have the same distance, which is used to ensure that the sub-bubbles arrive at the merging point at the same time for fixed-point fusion.

3. The method according to claim 2, characterized in that: The superhydrophobic track is located on a planar substrate, and the other planar areas of the substrate are non-hydrophobic surfaces except for the superhydrophobic track region; the coating microstructure of the superhydrophobic track is controlled at the submicron level, so that the thickness of the attached air layer is also on the same order of magnitude.

4. The method according to claim 2, characterized in that: The bubble moves in a straight line along the upstream main track. After reaching the split point, it splits into two equal-sized sub-bubbles. Each sub-bubble moves a distance according to the preset left and right branch shapes to avoid obstacles. It reaches the confluence point through the inverted Y-shaped fork structure. The two branch sub-bubbles merge into one bubble and enter the downstream main track.

5. The method according to claim 2, characterized in that: The bubble can avoid obstacles as needed by changing the bifurcation angle θ of the bifurcation and merging tracks and the shape of the left and right branch tracks.

6. The method according to claim 3, characterized in that: Without changing the width of the branch track, the size of the bubble after splitting can be adjusted by changing the initial bubble diameter.

Images