Method for regulating the behavior of a liquid metal

Abstract

The application provides a method for regulating the behavior of liquid metal, which comprises the following steps: compounding pure liquid metal with a second phase material to form a liquid metal composite which remains flowable at room temperature or in a heated state; determining the initial wetting state of a target solid surface to the pure liquid metal, which is either a non-wetting non-spreading state or a wetting spreading state; and based on the initial wetting state, using a physical induction method or a chemical induction method to act on the liquid metal composite, specifically: if the initial state is a non-wetting non-spreading state, then making the liquid metal composite wet and spread on the solid surface; if the initial state is a wetting spreading state, then making the liquid metal composite shrink and dewet on the solid surface. The application can realize the wetting and spreading or the shrinking and dewetting of liquid metal on a solid surface which originally does not spread or spreads in a simple, low-cost and scalable manner.

Description

Technical Field

[0001] This invention relates to the field of liquid metal behavior control technology, and in particular to a method for controlling the behavior of liquid metal. Background Technology

[0002] Liquid metals, as an emerging class of functional materials, possess both metallic and fluid properties, showing broad application prospects in many fields such as energy conversion and storage, heat transfer and dissipation, flexible electronics, and biomedicine. In practical applications, the wettability of liquid metals on solid surfaces will significantly affect the realization of their functions. Therefore, the regulation of the wetting behavior of liquid metals has attracted much attention.

[0003] Current research mainly focuses on two approaches to achieve the wetting and spreading of liquid metals: controlling the solid surface structure and introducing an interface layer. For example, patent application CN104357795A describes processing multiple spherical or ellipsoidal holes with specific depths and center-to-center spacing on a non-wetting surface to achieve the spreading of liquid metals on the non-wetting surface; while patent application CN108754422A describes depositing a continuous Ga2O3 film on the surface of a non-wetting solid sheet, and then reducing and annealing the Ga2O3 film to form a composite structure film with a Ga2O3 layer / Ga-O mixed layer / metallic Ga layer structure from the inside out, to achieve the spreading of liquid metals on the solid sheet surface. The limitations of these methods are that they either require complex micro-nano fabrication on the solid surface, which is inefficient and expensive, or they require the introduction of expensive high-end instruments and equipment (such as photolithography machines, ultrafast lasers, vapor deposition furnaces, etc.), and even require the design and synthesis of chemical substances with complex structures, which are not easy to scale up.

[0004] On the other hand, previous studies have focused more on the wetting and spreading of liquid metals on solid surfaces, with less attention paid to their dewetting behavior. The invention patent with publication number CN111534841A describes the reversible wetting of liquid metal on a porous metal mesh with micro / nano structures under electric field induction. Although it involves dewetting, this method requires not only the construction of special surface microstructures but also the simultaneous introduction of an external electric field to maintain and switch the wetting state of the liquid metal, which is also unfavorable for practical applications in many scenarios. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling the behavior of liquid metal, which aims to achieve the wetting, spreading, shrinking and dewetting of liquid metal on solid surfaces that were not originally spreading or spread in a simple, low-cost, and scalable manner.

[0006] In a first aspect, the present invention provides a method for controlling the behavior of liquid metal, the method comprising:

[0007] Pure liquid metal is combined with a second-phase material to form a liquid metal composite that retains fluidity at room temperature or under heating conditions.

[0008] Determine the initial wetting state of the target solid surface to the pure liquid metal, wherein the initial wetting state is either a non-wetting and non-spreading state or a wetting and spreading state;

[0009] Based on the initial wetting state, the liquid metal composite is acted upon using a physical induction method or a chemical induction method, specifically as follows:

[0010] If the initial state is non-wetting and non-spreading, then the liquid metal composite is made to wet and spread on the solid surface;

[0011] If the initial state is a wetted and spreadable state, the liquid metal composite will shrink and dewet on the solid surface.

[0012] In some embodiments, the pure liquid metal is a metal or alloy with a melting point below 330°C, including one or more of alkali metals, zinc group metals, late transition metals and their alloys.

[0013] In some embodiments, the second phase material includes one or more of inorganic non-metallic, metallic, polymeric or composite material particles, foils, and sheets;

[0014] The inorganic non-metals include hard carbon, soft carbon, graphene, carbon nanotubes, activated carbon, and metal oxides;

[0015] The metals include aluminum, zinc, tin, bismuth, iron, nickel, and their alloys.

[0016] In some embodiments, the composite method of the pure liquid metal and the second phase material includes:

[0017] The second phase material is uniformly dispersed and mixed into the liquid metal matrix by mechanical stirring or vibration, with the mass ratio of the second phase to the liquid metal being 1%-40%:1;

[0018] Alternatively, liquid metal can be spread on the surface of the second phase material to form a layered structure, with the thickness of the liquid metal being 1-100 μm.

[0019] In some embodiments, the non-wetting and non-spreading state is when liquid metal condenses into spherical or hemispherical shapes on a solid surface due to high surface tension, and the wetting and spreading state is when liquid metal forms a continuous thin film or a flat spreading layer on a solid surface.

[0020] In some embodiments, the physical induction method includes one or more of brushing, printing, casting, scraping, magnetic traction, ultrasonic vibration, electrowetting, photothermal irradiation, or temperature gradient driving, and the physical induction method is used to achieve the transformation from a non-wetting and non-spreading state to a wetted and spreading state.

[0021] In some embodiments, the chemical induction method is to drop, spray, or immerse the liquid metal composite or the solid surface with one or more of the following: acid, alkali, salt solution, water, alcohol solution, oxidizing solution, or reducing solution.

[0022] The chemical induction method is used to achieve the transformation from a wetting and spreading state to a shrinking and dewetting state.

[0023] In some embodiments, after the shrinkage and dewetting occurs, the liquid metal composite forms discrete micron- or submillimeter-sized particles on the solid surface.

[0024] In some embodiments, the liquid metal retains its liquid properties after being combined with the second phase.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. By combining pure liquid metal with a second-phase material to form a liquid metal composite that retains its fluidity, the surface tension, interfacial energy, and rheological properties of the pure liquid metal are fundamentally altered without changing its bulk metallic properties. The introduction of the second-phase material can effectively reduce the surface tension of the liquid metal, disrupt the continuity of its surface oxide film, or provide additional physical anchoring points, thereby enabling the liquid metal, which was originally difficult to spread due to high surface tension, to acquire the ability to be induced to spread. Furthermore, this composite method is simple to operate, requiring only mechanical stirring, vibration, or simple layering, without the need for complex chemical synthesis or high-temperature, high-pressure conditions, exhibiting good process compatibility and scalability potential.

[0027] 2. The method of this invention, when initially non-wetting and non-spreading, employs physical induction methods such as brushing, printing, casting, and magnetic traction to induce rapid, uniform, and controllable wetting and spreading of the liquid metal composite on the solid surface. Physical induction methods eliminate the need for additional chemical reagents, avoiding chemical contamination and side reactions, making them particularly suitable for electronic devices or biomedical applications requiring high purity. Simultaneously, brushing and printing methods enable large-area, patterned spreading with a minimum spreading thickness as low as a few micrometers, exhibiting excellent continuity and adhesion, providing an efficient and low-cost solution for the fabrication of ultrathin liquid metal functional layers.

[0028] 3. The method of this invention, when initially in a wetted and spreading state, utilizes chemical reagents such as water, acid, alkali, or salt solutions, through dropwise or spraying, to trigger the rapid contraction and dewetting of the liquid metal composite from its spread state within seconds by utilizing the corrosion reaction between the second-phase substance and the specific solvent, forming discrete micron- or submillimeter-sized particles. This process requires no external electric field, high temperature, or complex lighting conditions; the reaction conditions are mild, and the response speed is extremely fast, making it particularly suitable for scenarios requiring rapid interruption of conductive pathways or reversible desorption of liquid metals. Compared to traditional methods that rely on micro / nano structures or continuous electric fields to maintain the dewetting state, the chemical triggering method of this invention is simpler, more reliable, and easier to integrate into automated processes.

[0029] 4. This invention achieves reversible switching between a wetting and spreading state and a shrinking and dewetting state of a liquid metal composite by alternately employing physical and chemical induction methods on the same solid surface. This reversible control capability allows the liquid metal to be repeatedly used on the same device or surface, for example, switching the conductive pattern according to the operating frequency in a reconfigurable antenna, or repeatedly repairing open circuits in a self-healing circuit. Compared to the often irreversible changes in the wetting state in existing technologies, this significantly improves the utilization efficiency of liquid metal materials and the functional flexibility of devices, providing key underlying technical support for intelligent reconfigurable electronic systems. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the method for altering the wetting behavior of liquid metal on a solid surface provided by the present invention.

[0031] Figure 2 (a) is a schematic diagram of the non-wetting spreading of molten pure lithium in contact with copper foil in Example 1. Figure 2 (b) is a schematic diagram showing the state changes of molten pure lithium before and after being combined with hard carbon. Figure 2 (c) is a schematic diagram of the spreading of molten lithium-hard carbon composite on the surface of copper foil by brushing;

[0032] Figure 3 Indium-bismuth alloy spread in Example 2 67.66 Bi 32.34 A diagram illustrating the process of shrinkage and dewetting induced by boiling water after forming a composite layer with aluminum foil;

[0033] Figure 4 (a) is a schematic diagram of a pure gallium thin film that is stably spread and does not dewetting in Example 3. Figure 4 (b) SEM and EDS images of broken aluminum foil dispersed in liquid gallium metal matrix. Figure 4 (c) is a diagram showing the process of shrinkage and dewetting of the thin layer of gallium-aluminum paste under room temperature water induction.

[0034] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0036] Example 1

[0037] Step S1: In an argon glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), pure metallic lithium (melting point 180℃) is heated to 260℃ and molten. Hard carbon particles with a particle size ≤10 μm are added to the molten lithium, with a hard carbon to lithium mass ratio of 3:10 (i.e., 30%:1). The hard carbon is uniformly dispersed by mechanical stirring (300 rpm, 15 min) to form a hard carbon-lithium liquid metal composite that still maintains fluidity.

[0038] Step S2: Take a drop of pure lithium metal (about 50 μL) and drop it onto the surface of copper foil. It is observed that the pure lithium condenses into a spherical shape due to the surface tension (~400 mN / m), with a contact angle of about 135°, and is judged to be in a "non-wetting and non-spreading state".

[0039] Step S3: Take 50 μL of the above hard carbon-lithium composite and apply it to the copper foil surface using a nylon brush (bristle diameter 0.5 mm). The brushing speed is about 5 cm / s, and the brushing is repeated 3 times. The brushing area is 2 cm × 2 cm.

[0040] Test results: Pure lithium metal exhibits a contact angle as high as 135° on the copper foil surface, displaying a spherical condensation state and being completely non-wetting; while the contact angle of the hard carbon-lithium composite is significantly reduced to 28°. After coating, a continuous lithium metal film with a thickness of approximately 15 μm and an area of ​​4 cm² can be formed on the copper foil surface, with no breaks or pinhole defects observed under an optical microscope. The spreading time from droplet addition to complete coverage is only 8 seconds, and a single coating can be extended to over 25 cm². This example fully demonstrates that the present invention, through second-phase composite and physical induction, enables the rapid, uniform, and large-area controllable spreading of originally non-wetting liquid metal on a solid surface, providing a simple and low-cost solution for the preparation of ultrathin lithium metal anodes.

[0041] Example 2

[0042] Step S1: Place the indium-bismuth alloy In on a hot plate (120°C). 67.66 Bi 32.34 (Melting point 72.5℃) Heated to a molten state. A 20 μm thick aluminum foil was used as the second phase material. Molten indium-bismuth alloy was spread onto the aluminum foil surface by brushing, forming a layered composite structure. The indium-bismuth alloy coating thickness was approximately 50 μm. In this layered structure, the liquid metal and the second phase material were in close contact, and the liquid metal maintained complete fluidity.

[0043] Step S2: Take a drop of pure indium bismuth alloy liquid and spread it on the surface of aluminum foil. Observation shows that the thin layer of pure indium bismuth alloy is in a metastable spreading state due to the presence of surface oxide film, with a contact angle of about 42°. This state is relatively stable and does not easily undergo spontaneous dewetting, and is judged as "wetting spreading state".

[0044] Step S3: Add boiling water (100°C) to the surface of the aluminum foil coated with the indium bismuth alloy thin layer and observe the surface changes. Thanks to the activation effect of the alloying elements in the indium bismuth alloy on the aluminum, the aluminum foil and water undergo a rapid chemical corrosion reaction under high temperature conditions. The resulting gas and interfacial energy changes disrupt the original spreading equilibrium.

[0045] Step S4: Collect the indium bismuth alloy microparticles formed after dewetting from the aluminum foil surface, reheat to 120°C to melt, and then coat and spread them on the new aluminum foil surface again. Add boiling water again to induce dewetting, and repeat the cycle 3 times.

[0046] Test results: The pure indium bismuth alloy thin layer spread in a metastable state on the aluminum foil surface with a contact angle of approximately 42°. Even after 30 minutes of natural cooling, no significant dewetting was observed. However, with the laminated composite structure, thanks to the activation effect of the alloying elements in the indium bismuth alloy on the aluminum, rapid dewetting was triggered in only about 4 seconds after the addition of boiling water. The spread indium bismuth alloy thin layer rapidly contracted, forming a large number of tiny particles with a particle size distribution of 10-30 μm, achieving a dewetting area coverage exceeding 95%. Obvious corrosion marks were visible on the aluminum foil surface after dewetting, confirming that the chemical corrosion reaction between aluminum and water is the key mechanism triggering dewetting. This composite material, after collection and remelting, can be spread again on the surface of new aluminum foil, and the dewetting response speed remains within 5 seconds after three reversible cycles. This embodiment fully demonstrates the effectiveness of the layered composite structure combined with the chemical induction method in this invention. Through the direct contact between liquid metal and aluminum foil and the activation effect of alloying elements on aluminum, the originally metastable indium-bismuth alloy can be rapidly and thoroughly dewetting under high-temperature water triggering, providing a feasible technical solution for applications such as thermal switches and triggerable thermal interface materials.

[0047] Example 3

[0048] Step S1: At room temperature (25℃), take 5 g of pure liquid gallium (melting point 29.8℃) in a glass dish. Crush an 18 μm thick aluminum foil into micro-flakes by mechanical grinding (grinding jar speed 400 rpm, time 20 min) and disperse it into the liquid gallium matrix. The mass ratio of aluminum to gallium is 2:10 (i.e. 20%:1), forming an aluminum-gallium liquid metal composite slurry that retains complete fluidity after composite formation.

[0049] Step S2: Spread pure gallium droplets onto a flat glass plate surface. Observation shows that the pure gallium thin layer is metastable due to the presence of the surface oxide film (Ga2O3), with a contact angle of about 45°. Even when room temperature liquid water is added, spontaneous dewetting does not occur, which is determined to be "wetting and spreading state".

[0050] Step S3: The above aluminum-gallium composite paste is spread onto the surface of a dry, flat glass slide using a casting method to form a thin layer with a thickness of approximately 30 μm. Room temperature (25°C) deionized water is dropped onto the solid surface at room temperature, and the surface changes are observed. Thanks to the activation effect of gallium on aluminum, the aluminum micro-flakes undergo a chemical corrosion reaction with water, generating hydrogen gas and disrupting the interfacial equilibrium.

[0051] Step S4: Collect the aluminum-gallium composite microparticles formed after dewetting, re-grind and disperse them mechanically, spread them on the glass plate surface again, add water again to induce dewetting, and repeat 5 times.

[0052] Test results: The pure gallium thin film spread in a metastable state on the glass surface with a contact angle of approximately 45°. Even after adding room temperature liquid water and allowing it to stand for 10 minutes, there was no significant dewetting phenomenon, indicating that the surface oxide film of gallium played a role in stabilizing the spread state. In contrast, the contact angle of the aluminum-gallium composite paste decreased slightly to approximately 38° after spreading. After adding room temperature water, rapid dewetting occurred in only about 3.5 seconds, and the spread thin film quickly contracted to form tiny particles with an average particle size of approximately 7.2 μm. Simultaneously, obvious hydrogen bubbles were observed to be generated, confirming the activation effect of gallium on aluminum and the occurrence of the aluminum-water corrosion reaction. The collected microparticles, after being re-ground and dispersed, could be spread again and dewetting induced by water again. After five reversible cycles, the response time remained within 5 seconds, and the material recovery rate exceeded 90%. This embodiment fully demonstrates the effectiveness of the present invention in enabling liquid metals to acquire chemically triggered dewetting capabilities through mechanical dispersion and composite methods. In particular, by utilizing the activation effect of gallium on aluminum, gallium-based liquid metals that are originally insensitive to water can rapidly dewet under room temperature water triggering, providing a simple and low-cost solution for applications such as humidity sensors and disposable circuit fuses.

[0053] Example 4

[0054] Step S1: At room temperature, take 5 g of pure liquid gallium and add Fe3O4 magnetic particles with an average particle size of 5 μm. The mass ratio of Fe3O4 to gallium is 1:10 (10%:1). Disperse the particles evenly by ultrasonic vibration (power 100 W, time 10 min) to form a magnetic gallium-based liquid metal composite.

[0055] Step S2: Drop pure gallium liquid onto the surface of a polyimide (PI) film with a contact angle of approximately 130°, which is determined to be a "non-wetting and non-spreading state".

[0056] Step S3: Place a neodymium magnet (surface magnetic field strength 0.3 T) under the PI film, and drop the magnetic gallium-based composite onto the surface of the PI film. Under the action of the magnetic field, the composite automatically spreads towards the magnet, and the spreading area is patterned by moving the magnet.

[0057] Step S4: After removing the magnet, the composite remains in a spread state; applying a reverse magnetic field or mechanical disturbance can induce partial contraction, achieving partial reversible control of the wetting state.

[0058] Test results: Pure gallium exhibits a contact angle of 130° on the polyimide film surface, demonstrating complete non-wetting. Without a magnetic field, the contact angle of the Fe3O4-Ga composite is approximately 125°, roughly equivalent to that of pure gallium. However, after applying a 0.3T magnetic field, the contact angle drops sharply to 22°, and the composite rapidly spreads towards the magnet within 5 seconds. Patterning with a linewidth of 0.5mm can be achieved by moving the magnet. The composite's saturation magnetization is 8.2 emu / g, and it can be reversibly controlled at least 10 times between magnetization and demagnetization without performance degradation. This embodiment fully demonstrates that by introducing a magnetic second phase and combining it with magnetic field induction, this invention enables remote, non-contact, and patternable rapid spreading of liquid metal on originally non-wetting surfaces, providing a novel control method for applications requiring dynamically adjustable liquid metal patterns, such as reconfigurable antennas and smart RF devices.

[0059] Comparative Example 1

[0060] This comparative example is basically the same as Example 1, except that only pure metallic lithium (melting point 180°C) is used, without adding any second phase material; and pure molten lithium is spread on the surface of copper foil by brushing.

[0061] Test results: Pure lithium exhibited a contact angle as high as 135° on the copper foil surface. During coating, lithium droplets rolled in a spherical shape, failing to form a spreadable film on the copper foil surface. This comparative example illustrates that without the "composite step," i.e., without using a second phase material to composite with the liquid metal, the pure liquid metal, due to its extremely high surface tension, cannot spread on a previously non-wetting solid surface even using physical operations such as coating.

[0062] Comparative Example 2

[0063] This comparative example is basically the same as Example 3, except that no induction operation is performed.

[0064] Test results: The initial contact angle of the composite after spreading was 38°, indicating good spreading. However, there was no significant change after 30 minutes, and only slight surface oxidation occurred after 24 hours, with no obvious dewetting shrinkage. This comparative example illustrates that even if the physicochemical properties of the liquid metal and the second phase are altered, the transition from the spreading state to the dewetting state cannot be actively triggered without appropriate induction methods, thus losing the core technical effect of on-demand control of wetting behavior of this invention.

[0065] In summary, this invention forms a liquid metal composite that retains its fluidity by combining pure liquid metal with a second-phase material. Based on the initial wetting state of the target solid surface to the pure liquid metal, it selectively employs physical induction methods (such as brushing, printing, magnetic traction, etc.) to achieve the transition from non-wetting to wetting and spreading, or chemical induction methods (such as adding water, acid, alkali, salt solutions, etc.) to achieve the transition from wetting and spreading to shrinkage and dewetting. Simultaneously, it supports multiple reversible cycles on the same solid surface. Test results show that: after brushing, the contact angle of the hard carbon-lithium composite decreased from 135° to 28°, forming a 15μm thick continuous lithium film within 8 seconds; the aluminum-gallium composite dewetted within 3.5 seconds after being triggered by room temperature water; the indium-bismuth alloy-aluminum foil laminate rapidly dewetted within 4 seconds after being triggered by boiling water; and the magnetic Fe3O4-Ga composite decreased from 130° to 22° under a magnetic field, completing patterned spreading within 5 seconds. All these reversible cycles can be repeated more than 5 times. Compared with traditional methods, this invention does not require complex micro-nano fabrication (no need for expensive equipment such as photolithography machines and vapor deposition furnaces), complex chemical synthesis and structural design, and the operating equipment cost is as low as several hundred yuan. It is easy to prepare on a large scale. At the same time, it is the first to achieve bidirectional reversible control of the wetting and spreading and shrinking and dewetting of liquid metal on the same solid surface. It provides a simple, low-cost and scalable technical solution for fields such as flexible electronics, reconfigurable antennas, thermal interface materials, microfluidic switches, self-healing conductive circuits and smart wearable devices.

[0066] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A method for controlling the behavior of liquid metal, characterized in that, The method includes: Pure liquid metal is combined with a second-phase material to form a liquid metal composite that retains fluidity at room temperature or under heating conditions. Determine the initial wetting state of the target solid surface to the pure liquid metal, wherein the initial wetting state is either a non-wetting and non-spreading state or a wetting and spreading state; Based on the initial wetting state, the liquid metal composite is acted upon using a physical induction method or a chemical induction method, specifically as follows: If the initial state is non-wetting and non-spreading, then the liquid metal composite is made to wet and spread on the solid surface; If the initial state is a wetted and spreadable state, the liquid metal composite will shrink and dewet on the solid surface.

2. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, The pure liquid metal is a metal or alloy with a melting point below 330°C, including one or more of alkali metals, zinc group metals, late transition metals and their alloys.

3. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, The second phase material includes one or more of the following: inorganic non-metallic materials, metallic materials, polymeric materials, or composite materials, such as particles, foils, and sheets; The inorganic non-metals include hard carbon, soft carbon, graphene, carbon nanotubes, activated carbon, and metal oxides; The metals include aluminum, zinc, tin, bismuth, iron, nickel, and their alloys.

4. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, The composite method of the pure liquid metal and the second phase material includes: The second phase material is uniformly dispersed and mixed into the liquid metal matrix by mechanical stirring or vibration, with the mass ratio of the second phase to the liquid metal being 1%-40%:1; Alternatively, liquid metal can be spread on the surface of the second phase material to form a layered structure, with the thickness of the liquid metal being 1-100 μm.

5. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, The non-wetting and non-spreading state refers to the liquid metal condensing into spherical or hemispherical shapes on the solid surface due to high surface tension, while the wetting and spreading state refers to the liquid metal forming a continuous thin film or a flat spreading layer on the solid surface.

6. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, The physical induction method includes one or more of the following: brushing, printing, casting, scraping, magnetic traction, ultrasonic vibration, electrowetting, photothermal irradiation, or temperature gradient driving. The physical induction method is used to achieve the transformation from a non-wetting and non-spreading state to a wetted and spreading state.

7. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, The chemical induction method is to drop, spray, or immerse the liquid metal composite or the solid surface with one or more of the following: acid, alkali, salt solution, water, alcohol solution, oxidizing solution, or reducing solution. The chemical induction method is used to achieve the transformation from a wetting and spreading state to a shrinking and dewetting state.

8. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, After the shrinkage and dewetting occurs, the liquid metal composite forms discrete micron- or submillimeter-sized particles on the solid surface.

9. The method for controlling the behavior of liquid metal according to claim 1, characterized in that, The liquid metal retains its liquid properties after being combined with the second phase.

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