A high-speed in-situ rotational motion device driven by droplet surface energy

Abstract

The present invention provides a high-speed in-situ rotating motion device driven by the surface energy of liquid droplets, which belongs to the field of liquid droplet energy conversion technology. The high-speed in-situ rotating motion device includes a rotating main body component, a liquid droplet transport track and a rotating center component. The surface of the rotating main body component with super-hydrophobic properties is evenly distributed with a super-hydrophilic liquid droplet transport track for capturing and transporting liquid droplets. The reverse thrust generated in the process of liquid droplets being transported along the hydrophilic track with a certain spiral angle and injected into the water can drive the rotating main body component to rotate around the axis, and the continuous dripping of liquid droplets can generate continuous in-situ rotational motion. The present invention provides a new idea for the utilization of liquid droplet surface energy, especially for the surface energy of dense, large-volume, and high-speed droplets, and has the advantages of simple operation, low cost, fast response, and long life, and has broad application prospects in the field of droplet energy collection and conversion.

Description

Technical Field

[0001] The present invention belongs to the technical field of droplet energy conversion, and relates to a droplet-driven motion device capable of high-speed in-situ rotation, which realizes the utilization of droplet surface energy. Background Art

[0002] Liquid surface energy refers to the energy state of the surface layer of liquid molecules. Common droplets, such as raindrops and dewdrops, are formed by the evaporation of surface water and its cooling. As the volume increases, the surface area increases, and the surface energy increases. However, there is currently a lack of methods and means to effectively utilize the large amount of surface energy contained in droplets, and researchers have devoted considerable effort to this end. In recent years, extreme wettability surfaces, such as superhydrophobic and superhydrophilic surfaces, have shown potential application value in the field of droplet energy conversion. The paper Lab on a Chip, 2014, 14, 1538, reports a phenomenon in which a droplet dropped onto a superhydrophilic pattern surrounded by a superhydrophobic region can spontaneously transport itself, converting the droplet's surface energy into its kinetic energy or gravitational potential energy. In addition to converting the droplet's surface energy into its own mechanical energy, the droplet's surface energy can also be converted into the mechanical energy of other objects. The literature Advanced Functional Materials, 2020, 30 (16), 1910599 and Nano Energy, 2022, 101, 107543 reported a phenomenon in which when a droplet falls on a super-hydrophilic hole or gap on a super-hydrophobic surface, the droplet passes through the hole or gap to generate a jet, thereby driving the super-hydrophobic boat to move on the water surface, realizing the conversion of the droplet surface energy to the super-hydrophobic boat kinetic energy. However, this design has high requirements for the droplet droplet position, and due to the limitation of the super-hydrophilic hole or gap, the droplet surface energy is difficult to be completely released in a short time, which to a certain extent hinders the driving of large-sized droplets on the device. Furthermore, the literature Chemical Engineering Journal, 2022, 446, 136874 and Results in Engineering, 2022, 14, 100388 finally realizes the rapid conversion of droplet surface energy to boat kinetic energy by designing a super-hydrophilic wedge pattern on the surface of the super-hydrophobic boat. However, this design only enables linear motion of the boat; droplet-driven rotational motion on the water surface has not yet been reported. Furthermore, the supply of droplets to drive the boat's linear motion requires adjustment based on the boat's position, which introduces uncertainty and hinders the collection of surface energy from dense, large, and high-velocity droplets. While installing a water reservoir on the boat can alleviate this problem to some extent, an integrated design increases the boat's overall mass, thereby reducing both driving efficiency and the conversion rate of droplet surface energy. Summary of the Invention

[0003] In view of the problems existing in the existing droplet surface energy utilization, the present invention provides a device with a simple structure that can utilize the droplet surface energy to achieve high-speed in-situ rotational motion.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A high-speed in-situ rotating motion device driven by the surface energy of a liquid droplet comprises a rotating main body component 1, a liquid droplet transport track 2 and a rotating center component 3.

[0006] The rotating main body component 1 is in the shape of a circular sheet with a thickness of less than 1 mm and a small hole in the center for installing the super-hydrophobic rotating central component 3; the upper and lower surfaces of the rotating main body component 1 are super-hydrophobic, and the hole is hydrophilic.

[0007] The droplet transport track 2 is hydrophilic, with its edge curve forming an equiangular spiral extending from the center of the rotating main component 1 to the outer edge. The shape of the droplet transport track 2 can be controlled by adjusting the helix angle of the helix, which ranges from 90 degrees to 90 degrees. Simply put, a spiral hydrophilic pattern is evenly distributed on one side of the surface of the super-hydrophobic rotating main component 1, serving as the droplet transport track 2.

[0008] The rotating central component 3 is a cylinder with a super-hydrophobic surface, and the contact angle of water droplets thereon is greater than 150 degrees. The size of the rotating central component 3 is slightly smaller than the size of the central hole of the rotating main component 1.

[0009] The high-speed in-situ rotating motion device is floated on the water surface, and the droplets dripping on the rotating main body component 1 will be captured by the droplet transport track 2 in a relatively short time. Then, under the action of the unbalanced Laplace pressure before and after the droplets, they are transported along the spiral droplet transport track 2 and injected into the water at the edge of the rotating main body component 1. The rotating main body component 1 generates in-situ rotational motion under the action of the reverse thrust generated during the droplet entering the water. The entire process realizes the conversion between the surface energy of the droplets and the kinetic energy of the rotating main body component 1.

[0010] Furthermore, the helix angle of the edge helix of the droplet transport track 2 can be adjusted according to the rotation speed requirement.

[0011] Furthermore, the number of the droplet transport tracks 2 can be increased or decreased according to the droplet flow rate and density, and the preferred number is 4 to 10.

[0012] Furthermore, in order to obtain a greater driving force, the width of the end of the droplet transport track 2 is adjusted according to the size of the droplets, and the preferred size range is: 4 to 12 mm.

[0013] Furthermore, the rotating main body component 1 is made of a material with low density that can float on the water surface, including metal or non-metallic plates.

[0014] Furthermore, the rotating main body component 1 is obtained through laser processing / chemical etching / electrochemical etching and low-surface-energy modification, resulting in a water droplet contact angle greater than 150 degrees on its surface. A droplet transport track 2 is processed on one side of the rotating main body component 1 through laser processing / masked chemical etching / masked electrochemical etching, resulting in a water droplet contact angle less than 10 degrees on the droplet transport track 2.

[0015] Compared with the existing device that uses the surface energy of droplets for driving, the present invention has the following advantages:

[0016] (1) By introducing a spiral hydrophilic pattern on the disk surface, a rotational motion driven by the surface energy of the droplet is achieved.

[0017] (2) The edge of the spiral hydrophilic track is an equiangular spiral. The direction of the driving force generated by the droplet during transportation on the track is controllable, and the angle between it and the center of the circle is a constant value, which is determined by the spiral angle of the equiangular spiral.

[0018] (3) The in-situ rotational motion around the axis does not require precise droplet placement. The supply of droplets does not need to be adjusted with the movement of the device. The device can be continuously driven by continuously dripping droplets, simplifying the operation and saving space.

[0019] (4) The size of the device can be adjusted according to the dripping area of ​​the collected droplets. The hydrophilic track can be reasonably designed, which is more friendly to the collection of the surface energy of dense, large-volume, and high-speed droplets, and can improve the droplet energy collection and utilization rate.

[0020] (5) The special design of the central symmetrical distribution of the hydrophilic track and the wettability of the central axis and hole surface is conducive to reducing the friction and resistance encountered by the disk during movement, improving the maneuverability of the device while also improving the energy conversion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of a droplet-driven motion device capable of high-speed in-situ rotation according to the present invention.

[0022] Figure 2 Schematic diagram of the hydrophilic and hydrophobic regions of the sports device of the present invention.

[0023] In the figure: 1 is the rotating main body component, 2 is the droplet transport track, and 3 is the rotating center component. Specific implementation plan

[0024] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0025] Example 1

[0026] The structure of a droplet-driven, high-speed, in-situ rotating motion device is shown in the figure. It comprises a rotating main component 1, a droplet transport track 2, and a rotating center component 3. The entire device is constructed from a 0.3mm thick aluminum alloy base material. The rotating main component 1 has a diameter of 60mm. The rotating main component 1 is laser processed and modified with a low surface energy, resulting in a water droplet contact angle of 162 degrees on its surface. The droplet transport track 2 is machined onto one side of the rotating main component 1 using masked electrochemical etching, creating a water droplet contact angle of approximately 0 degrees. The machined surface of the droplet transport track 2 serves as the upper surface when the entire device floats on water. The edge curve of the droplet transport track 2 is an equiangular spiral with a helix angle of 75 degrees. There are six droplet transport tracks 2, each with an end arc length of 8mm, evenly distributed along the edge of the rotating main component 1. The surface of the rotating center component 3, with a diameter of 2mm, is chemically etched and modified with a low surface energy to impart superhydrophobicity, which allows it to interact with the 3mm hydrophilic pores in the center of the rotating main component 1 to create a fixed surface. Droplets dripping onto the device are captured and transported by the droplet transport track 2 until they are ejected into the water at the edge of the rotating main body 1. The rotating main body 1 moves in the opposite direction of the jet under the action of the jet's reverse thrust, and the device can be continuously driven by continuously dripping droplets.

[0027] Example 2

[0028] The structure of a droplet-driven, high-speed, in-situ rotating motion device is shown in the figure. It comprises a rotating main component 1, a droplet transport track 2, and a rotating center component 3. The entire device is constructed from a magnesium alloy substrate, with the rotating main component 1 having a diameter of 80 mm. The rotating main component 1 is chemically etched and modified to have a low surface energy, resulting in a water droplet contact angle of 158 degrees on its surface. The droplet transport track 2 is machined onto one side of the rotating main component 1 using laser etching, creating a water droplet contact angle of approximately 0 degrees. The machined surface of the droplet transport track 2 serves as the upper surface when the entire device floats on water. The edge curve of the droplet transport track 2 is an equiangular spiral with a helix angle of 60 degrees. There are 10 droplet transport tracks 2, each with a 6 mm end arc length, evenly distributed along the edge of the rotating main component 1. The surface of the rotating center component 3, with a diameter of 2 mm, is chemically etched and modified to have superhydrophobic properties, which interact with the 3 mm hydrophilic pores in the center of the rotating main component 1 to create a fixed surface. Droplets dripping onto the device are captured and transported by the droplet transport track 2 until they are ejected into the water at the edge of the rotating main body 1. The rotating main body 1 moves in the opposite direction of the jet under the action of the jet's reverse thrust, and the device can be continuously driven by continuously dripping droplets.

[0029] Example 3

[0030] The structure of a droplet-driven, high-speed, in-situ rotating motion device is shown in the figure. It comprises a rotating main component 1, a droplet transport track 2, and a rotating center component 3. The entire device is constructed from pure aluminum, with the rotating main component 1 having a diameter of 20 mm. The rotating main component 1 is fabricated through electrochemical etching and low-surface-energy modification, resulting in a water droplet contact angle of 160 degrees on its surface. The droplet transport track 2 is machined onto one side of the rotating main component 1 using masked chemical etching, achieving a water droplet contact angle of 2 degrees. The machined surface of the droplet transport track 2 serves as the upper surface when the entire device floats on water. The edge curve of the droplet transport track 2 is an equiangular spiral with a helix angle of 45 degrees. There are four droplet transport tracks 2, each with a terminal arc length of 4 mm, evenly distributed along the edge of the rotating main component 1. The surface of the rotating center component 3, with a diameter of 1 mm, is rendered superhydrophobic by chemical etching and low-surface-energy modification, and can interact with the 2 mm hydrophilic pores in the center of the rotating main component 1 to create a fixed surface. Droplets dripping onto the device are captured by the droplet transport track 2 and transported to the edge of the rotating main component 1, where they are then ejected into the water. The rotating main component 1 moves in the opposite direction of the jet under the reverse thrust of the jet, and the continuous dripping of droplets enables the device to be continuously driven.

[0031] The above-described embodiments merely express the implementation methods of the present invention, but should not be understood as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A high-speed in-situ rotational motion device driven by the surface energy of a liquid droplet, characterized in that: The device comprises a rotating main body component (1), a droplet transport track (2) and a rotating center component (3); The rotating main body component (1) is disc-shaped, and has a hydrophilic small hole in the center for mounting the rotating center component (3); the upper and lower surfaces of the rotating main body component (1) are super-hydrophobic; the droplet transport track (2) is super-hydrophilic, and the edge curve is an equiangular spiral extending from the center of the rotating main body component (1) to the outer edge, and the shape of the droplet transport track (2) can be controlled by adjusting the spiral angle of the spiral line; the rotating main body component (1) can freely rotate around the super-hydrophobic rotating center component (3); The high-speed in-situ rotating motion device is floated on the water surface. After the droplet transport track (2) quickly captures the droplets dripping on the surface of the device, the droplets are transported along the droplet transport track (2) to the edge of the rotating main component (1) and injected into the water. The rotating main component (1) generates a rotational motion under the action of the reverse thrust generated during the droplet entering the water. The whole process realizes the conversion between the surface energy of the droplet and the kinetic energy of the rotating main component (1).

2. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 1, characterized in that: The rotating main body component (1) is made of a material capable of floating on the water surface.

3. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 1, characterized in that: The central hole of the rotating main body component (1) is hydrophilic, and the contact angle of a water drop thereon is less than 90 degrees.

4. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 1, characterized in that: The number of the droplet transport tracks (2) is processed into different specifications according to the overall size of the device, the droplet flow rate and the droplet density.

5. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 4, characterized in that: The number of the droplet transport tracks (2) is 4 to 10.

6. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 1, characterized in that: The end width of the droplet transport track (2) is adjusted according to the size of the droplets.

7. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 6, characterized in that: The end width of the droplet transport track (2) is 4 to 12 mm.

8. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 1, characterized in that: The spiral angle of the equiangular spiral at the edge of the droplet transport track (2) is adjusted according to the rotation speed requirement and the droplet size.

9. The high-speed in-situ rotational motion device driven by droplet surface energy according to claim 1, characterized in that: The rotating central component (3) is a column with a super-hydrophobic surface, and the contact angle of a water droplet thereon is greater than 150 degrees.

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