Liquid metal conductive film and preparation method thereof, and liquid metal conductive pattern and preparation method thereof

Abstract

The invention discloses a liquid metal conductive film and a preparation method thereof, and a liquid metal conductive pattern and a preparation method thereof. The preparation method of the liquid metal conductive film specifically comprises the following steps: S1, carrying out ultrasonic atomization treatment on liquid metal to obtain metal liquid drops; s2, continuously dripping metal liquid drops on the substrate to finally obtain a liquid metal conductive thin film; the preparation method of the liquid metal conductive pattern comprises the following steps: S1, carrying out ultrasonic atomization treatment on liquid metal to obtain metal liquid drops; and S2, a mask plate method, a 3D multi-axis printing method or a direct-writing printing method is adopted, the metal liquid drops are continuously dropped on the substrate, and finally the liquid metal conductive pattern is obtained. Compared with the prior art, the preparation method can greatly improve the surface tension of the liquid metal, and the wettability of the liquid metal and various substrates is kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid metal preparation, and particularly relates to a liquid metal conductive film and a preparation method thereof, a liquid metal conductive pattern and a preparation method thereof. Background Art

[0002] Due to its excellent high conductivity, low toxicity, flow deformation and other characteristics, liquid metal has become a reliable choice for a new generation of functional materials. More and more researchers have started to use liquid metal to manufacture flexible and elastic wearable and implantable electronic devices. However, liquid metal has a high surface tension and poor wettability with common flexible and elastic substrates, and it is difficult to directly pattern. Using the microchannel method is an effective way to solve this problem. However, under large deformations (especially in the extrusion state), the microchannels are easily damaged, resulting in discontinuity of the liquid metal in the microchannels, thus leading to failure. In addition, due to the fluidity characteristics of liquid metal, the encapsulation process also needs to be considered to prevent the liquid metal from leaking out of the microchannels. In addition, the following methods are mainly adopted to pattern liquid metal: mixing with other materials, selecting surface wetting, ultrasonic and stirring dispersion, etc. The purpose of these methods is to change the surface tension of liquid metal so that it can better adhere to the substrate and achieve patterning. However, almost all the liquid metal patterns prepared by these methods require additional conductive activation, and at the same time, the conductivity is reduced, which is also a challenge restricting the application of liquid metal. Summary of the Invention

[0003] The purpose of the present invention is to provide a liquid metal conductive film and a preparation method thereof, a liquid metal conductive pattern and a preparation method thereof. By using the ultrasonic atomization method of liquid metal, the surface tension of liquid metal is changed, and a high-conductivity liquid metal pattern is rapidly prepared, effectively overcoming the problem that it is difficult to directly pattern due to the large surface tension of liquid metal.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a preparation method of a liquid metal conductive film, the preparation method specifically includes the following steps:

[0005] S1. Perform ultrasonic atomization treatment on liquid metal to obtain metal droplets;

[0006] S2. Continuously drop the metal droplets on the substrate, and two adjacent metal droplets are fused to obtain a conductive unit. Multiple conductive units are connected to obtain a conductive short chain, and multiple conductive short chains are fused and connected to finally obtain a liquid metal conductive film.

[0007] In the preparation process of the liquid metal conductive film of the present invention, under the action of ultrasonic waves, the liquid metal is torn from the initial liquid flow state into countless droplets. Since the external force received exceeds the surface tension of the liquid metal, these droplets will further break into tiny droplets. At the same time, ultrasonic waves have dual characteristics of wave and energy. The energy transmitted by them will give the droplets great speed and acceleration, causing them to fall rapidly and adhere to the substrate. In addition, the sharp rise in temperature or the applied air pressure also helps the rapid fusion between liquid metal droplets, thereby forming a highly conductive film.

[0008] Preferably, in the step S1, the liquid metal is composed of a main component and a balance component. The main component is selected from one of cesium, gallium, rubidium, potassium, sodium, indium, lithium, tin, bismuth, thallium, cadmium, lead, zinc, antimony, magnesium, aluminum and their alloys, and the balance component is selected from at least one of iron-based single metals, cobalt-based single metals, nickel-based single metals, copper-based single metals, silver-based single metals, multi-component magnetic metals, multi-component non-magnetic metals and solid non-metals.

[0009] Preferably, the step S1 specifically includes the following operations: After connecting the ultrasonic nozzle with the generator to output ultrasonic energy, the liquid metal is injected into the ultrasonic nozzle through an injection pump, and metal droplets are obtained after ultrasonic atomization treatment.

[0010] Preferably, the microscopic morphology of the metal droplets is dumbbell-shaped or spindle-shaped.

[0011] When the liquid metal particles after ultrasonic atomization (spraying) reach the substrate, these micron-sized particles are scattered on the substrate, with a small content and independent of each other. At this time, the particle shape is similar to a spindle. Since their quantity is small and isolated from each other, the entire substrate cannot conduct electricity. As time goes by, the number of particles deposited on the elastic substrate gradually increases, causing them to quickly fuse with the particles that have been previously deposited on the substrate, forming conductive units one by one. The interconnection between these conductive units constitutes the conductive short chains of the liquid metal. As the time for depositing atomized liquid metal particles on the elastic substrate further increases, the number of these particles will also gradually increase. At the same time, since a large amount of energy is released during the atomization of the liquid metal into particles, resulting in a temperature rise, or by choosing to pass gas, this also promotes the further fusion between conductive chains, forming a perfect conductive network.

[0012] Preferably, the frequency of the generator is 1 - 200 KHz, the power is 1 - 100 W; the flow rate of the injection pump is 0.01 - 20 ml / s, and the time for ultrasonic atomization is 0.1 - 5 h.

[0013] Preferably, in the step S2, the material of the substrate is one of flexible materials, elastic materials and hard materials, and the contact surface of the substrate is a plane or a curved surface.

[0014] Preferably, the flexible material is selected from one of cloth-based materials, paper-based, PI film, plastic film, PET film, PVA, animal, and plant epidermis; the elastic material is selected from one of PDMS, silica gel, Ecoflex, SBS elastomer, POE elastomer, aliphatic aromatic random copolyester, rubber, resin, hydrogel, polyurethane, styrene block copolymer, PVC, polyimide, poly(terephthalic acid) plastics, polyethylene octene coelastomer, and thermoplastic elastomer; the rigid material is selected from one of wood, PCB, FR4, polytetrafluoroethylene, silicon wafer, glass, and ITO.

[0015] Preferably, in the step S2, the dripping method is selected from gravity dripping or gas blowing, and the parameters of the gas blowing are as follows: the gas is selected from one of air, nitrogen, and argon, and the air pressure is 0.1 KPa - 5 MPa.

[0016] The second object of the present invention is to provide a liquid metal conductive film prepared by any of the above preparation methods.

[0017] The third object of the present invention is to provide a preparation method of a liquid metal conductive pattern, and the preparation method specifically includes the following steps:

[0018] S1. Perform ultrasonic atomization treatment on liquid metal to obtain metal droplets;

[0019] S2. Adopt a mask method, a 3D multi-axis printing method, or a direct writing printing method to drop the metal droplets on a substrate, and two of the metal droplets are fused with each other to obtain a conductive unit, multiple of the conductive units are connected with each other to obtain a conductive short chain, and after multiple of the conductive short chains are fused and connected with each other, a liquid metal conductive pattern is finally obtained.

[0020] During the preparation process of the liquid metal pattern of the present invention, under the action of ultrasonic waves, the liquid metal is torn from the initial liquid flow state into countless droplets. Since the external force received exceeds the surface tension of the liquid metal, these droplets will further break into tiny droplets. At the same time, ultrasonic waves have dual characteristics of wave motion and energy. The energy transmitted by it will give the droplets great speed and acceleration, making them quickly fall and adhere to the substrate. In addition, the sharp rise in temperature or the applied air pressure also helps the rapid fusion between liquid metal droplets, thereby forming a liquid metal pattern. There is no need to activate the circuit by means of mechanical sintering (pressing, scratching) or using the phase change of liquid metal (freezing), but a highly conductive liquid metal pattern can be directly obtained, and this pattern can be used as various single-layer and multi-layer flexible / elastic electronic devices such as electrodes, capacitors, sensors, antennas, and inductors.

[0021] Preferably, in the step S1, the liquid metal is composed of a main component and a balance component. The main component is selected from one of cesium, gallium, rubidium, potassium, sodium, indium, lithium, tin, bismuth, thallium, cadmium, lead, zinc, antimony, magnesium, aluminum and their alloys, and the balance component is selected from at least one of iron-based single-metal, cobalt-based single-metal, nickel-based single-metal, copper-based single-metal, silver-based single-metal, multi-component magnetic metals, multi-component non-magnetic metals and solid non-metals.

[0022] Preferably, the step S1 specifically includes the following operations: Connect the ultrasonic nozzle to the generator to output ultrasonic energy, inject the liquid metal into the ultrasonic nozzle through an injection pump, and obtain metal droplets after ultrasonic atomization treatment.

[0023] Preferably, the microscopic morphology of the metal droplets is dumbbell-shaped or spindle-shaped.

[0024] When the liquid metal particles after ultrasonic atomization (spraying) reach the substrate, these micron-sized particles are scattered on the substrate, with a small content and being independent of each other. At this time, the particle shape is similar to a spindle shape. Since their quantity is small and they are isolated from each other, the entire substrate cannot conduct electricity. As time goes by, the number of particles deposited on the elastic substrate gradually increases, causing them to quickly fuse with the particles that have been previously deposited on the substrate, forming conductive units one by one. The interconnection between these conductive units constitutes the conductive short chains of the liquid metal. As the time for depositing atomized liquid metal particles on the elastic substrate further increases, the number of these particles also gradually increases. At the same time, since a large amount of energy is released during the atomization of the liquid metal into particles, resulting in a temperature rise, or by choosing to pass gas, this also promotes the further fusion between the conductive chains, forming a complete conductive network.

[0025] Preferably, the frequency of the generator is 1 - 200 KHz, and the power is 1 - 100 W; the flow rate of the injection pump is 0.01 - 20 ml / s, and the ultrasonic atomization time is 0.1 - 5 h.

[0026] Preferably, in the step S2, the material of the substrate is one of flexible materials, elastic materials and hard materials, and the contact surface of the substrate is a plane or a curved surface.

[0027] Preferably, the flexible material is selected from one of cloth-based materials, paper-based, PI film, plastic film, PET film, PVA, animal, and plant epidermis; the elastic material is selected from one of PDMS, silica gel, Ecoflex, SBS elastomer, POE elastomer, aliphatic aromatic random copolyester, rubber, resin, hydrogel, polyurethane, styrene block copolymer, PVC, polyimide, poly terephthalic acid plastics, polyethylene octene coelastomer, and thermoplastic elastomer; the rigid material is selected from one of wood, PCB, FR4, polytetrafluoroethylene, silicon wafer, glass, and ITO.

[0028] Preferably, in step S2, the dripping method is selected from gravity dripping or gas blowing, and the parameters of the gas blowing are as follows: the gas is selected from one of air, nitrogen, and argon, and the air pressure is 0.1 KPa - 5 MPa.

[0029] The fourth object of the present invention is to provide a liquid metal conductive pattern prepared by the above preparation method.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] 1. The preparation method of the present invention can greatly improve the surface tension of liquid metal and keep its wettability with various substrates;

[0032] 2. The present invention discovers a new mechanism for the fusion of liquid metal particles to form a conductive path and adjusts the conductivity by controlling the atomization time;

[0033] 3. The liquid metal conductive pattern obtained by atomization (spraying) of the present invention has high conductivity directly without mechanical pressing or scratching and without freezing activation;

[0034] 4. The preparation cost of the present invention is low, the recovery rate is high, and large-area patterning and large-scale promotion can be carried out. Description of the Drawings

[0035] Figure 1 is the microscopic morphology diagram of liquid metal particles after ultrasonic atomization of liquid metal in Example 1 of the present invention;

[0036] Figure 2 is the microscopic morphology diagram during the fusion process of liquid metal particles in Example 1 of the present invention;

[0037] Figure 3 is the patterning of various substrates in Example 2 of the present invention;

[0038] Figure 4 is the resistance change of the conductive film in Example 1 of the present invention when the tensile strain is 0 - 700%;

[0039] Figure 5The stretchable circuit integrated with multiple circuit elements obtained in Embodiment 1 of the present invention. Detailed implementation manners

[0040] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the accompanying drawings.

[0041] It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0042] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the description of the present invention, which are obvious to those skilled in the art. Other implementation manners obtained from the description of the present invention are obvious to those skilled in the art. The description and embodiments of this application are only exemplary.

[0043] The specific implementation manners of the present invention provide a preparation method for a liquid metal conductive film, and the preparation method specifically includes the following steps:

[0044] S1. Perform ultrasonic atomization treatment on the liquid metal to obtain metal droplets. Specifically, after connecting the ultrasonic nozzle to the generator to output ultrasonic energy, inject the liquid metal into the ultrasonic nozzle through an injection pump, and obtain metal droplets after ultrasonic atomization treatment; the liquid metal is composed of a main component and a remaining component, and the main component is selected from one of cesium, gallium, rubidium, potassium, sodium, indium, lithium, tin, bismuth, thallium, cadmium, lead, zinc, antimony, magnesium, aluminum and their alloys, and the remaining component is selected from at least one of iron-based single metals, cobalt-based single metals, nickel-based single metals, copper-based single metals, silver-based single metals, multi-component magnetic metals, multi-component non-magnetic metals and solid non-metals;

[0045] S2. Continuously drop the metal droplets onto the substrate, and two metal droplets fuse with each other to obtain a conductive unit. Multiple conductive units are connected to each other to obtain a conductive short chain. After multiple conductive short chains are fused and connected to each other, a liquid metal conductive film is finally obtained. The material of the substrate is one of a flexible material, an elastic material and a hard material, and the contact surface of the substrate is a plane or a curved surface.

[0046] In the specific implementation manner, the frequency of the generator in step S1 is 1 - 200 KHz, and the power is 1 - 100 W; the flow rate of the injection pump is 0.01 - 20 ml / s, and the ultrasonic atomization time is 0.1 - 5 h.

[0047] In a specific embodiment, the microscopic morphology of the metal droplets is dumbbell-shaped or spindle-shaped.

[0048] In a specific embodiment, in step S2, the flexible material is selected from one of cloth-based materials, paper-based, PI film, plastic film, PET film, PVA, animals, and plant epidermis; the elastic material is selected from one of PDMS, silica gel, Ecoflex, SBS elastomer, POE elastomer, aliphatic aromatic random copolyester, rubber, resin, hydrogel, polyurethane, styrene block copolymer, PVC, polyimide, poly(terephthalic acid) plastics, polyethylene octene coelastomer, and thermoplastic elastomer; the rigid material is selected from one of wood, PCB, FR4, polytetrafluoroethylene, silicon wafer, glass, and ITO.

[0049] In a specific embodiment, in step S2, the method of dripping is selected from gravity dripping or gas blowing. The parameters of gas blowing are as follows: the gas is selected from one of air, nitrogen, and argon, and the air pressure is 0.1 KPa - 5 MPa.

[0050] The second object of the specific embodiment of the present invention is to provide a liquid metal conductive film prepared by the above preparation method.

[0051] The third object of the specific embodiment of the present invention is to provide a method for preparing a liquid metal conductive pattern. The preparation method specifically includes the following steps:

[0052] S1. Ultrasonic atomization treatment is performed on the liquid metal to obtain metal droplets. Specifically: after connecting the ultrasonic nozzle to the generator to output ultrasonic energy, the liquid metal is injected into the ultrasonic nozzle through an injection pump, and metal droplets are obtained after ultrasonic atomization treatment; the liquid metal consists of a main component and a remaining component. The main component is selected from one of cesium, gallium, rubidium, potassium, sodium, indium, lithium, tin, bismuth, thallium, cadmium, lead, zinc, antimony, magnesium, aluminum, and their alloys, and the remaining component is selected from at least one of iron-based single metals, cobalt-based single metals, nickel-based single metals, copper-based single metals, silver-based single metals, multi-component magnetic metals, multi-component non-magnetic metals, and solid non-metals.

[0053] S2. Using a mask template method, a 3D multi-axis printing method, or a direct writing printing method, the metal droplets are continuously dripped onto the substrate. Two metal droplets are fused with each other to obtain a conductive unit, multiple conductive units are connected to each other to obtain a conductive short chain, and multiple conductive short chains are fused and connected to finally obtain a liquid metal conductive pattern.

[0054] In a specific embodiment, in step S1, the frequency of the generator is 1 - 200 KHz, and the power is 1 - 100 W; the flow rate of the injection pump is 0.01 - 20 ml / s, and the time of ultrasonic atomization is 0.1 - 5 h.

[0055] In a specific embodiment, the microscopic morphology of the metal droplets is dumbbell-shaped or spindle-shaped.

[0056] In a specific embodiment, in step S2, the flexible material is selected from one of cloth-based materials, paper-based materials, PI films, plastic films, PET films, PVA, animal and plant epidermis; the elastic material is selected from one of PDMS, silica gel, Ecoflex, SBS elastomer, POE elastomer, aliphatic-aromatic random copolyester, rubber, resin, hydrogel, polyurethane, styrene block copolymer, PVC, polyimide, poly(terephthalic acid) plastics, polyethylene octene coelastomer, and thermoplastic elastomer; the rigid material is selected from one of wood, PCB, FR4, polytetrafluoroethylene, silicon wafers, glass, and ITO.

[0057] In a specific embodiment, in step S2, the dripping method is selected from gravity dripping or gas blowing. The parameters of gas blowing are as follows: the gas is selected from one of air, nitrogen, and argon, and the air pressure is 0.1 KPa - 5 MPa.

[0058] The fourth object of the specific embodiment of the present invention is to provide a liquid metal conductive pattern prepared by the above preparation method.

[0059] The technical effects of the present invention will be described below in conjunction with specific embodiments.

[0060] Example 1

[0061] This example provides a preparation method of a liquid metal conductive thin film. The preparation method specifically includes the following steps:

[0062] S1. Ultrasonic atomization treatment is performed on the liquid metal to obtain metal droplets. Specifically, after connecting the ultrasonic nozzle to the generator to output ultrasonic energy, the liquid metal is injected into the ultrasonic nozzle through a syringe pump. After ultrasonic atomization treatment, metal droplets are obtained. Under the action of ultrasonic waves, the liquid metal is broken into small droplets (spindle-shaped / dumbbell-shaped). As Figure 1 shown, the liquid metal is composed of a gallium-indium-tin ternary alloy;

[0063] S2. The metal droplets are continuously dripped onto the substrate. Two metal droplets fuse with each other to obtain a conductive unit. Multiple conductive units are connected to each other to obtain a conductive short chain. After multiple conductive short chains are fused and connected to each other, a liquid metal conductive thin film is finally obtained. The material of the substrate is silica gel.

[0064] In step S1, the frequency of the generator is 40 KHz and the power is 50 W; the flow rate of the syringe pump is 0.2 ml / s, and the ultrasonic atomization time is 04 h;

[0065] In step S2, the dripping method is gas blowing, and the parameters of gas blowing are as follows: the gas is air, the air pressure is 0.5 KPa, and the deposition time is 5 s. At this time, the liquid droplets will form a conductive network with the deposition of time, as Figure 2 shown.

[0066] Example 2

[0067] This example provides a method for preparing a liquid metal conductive pattern. The preparation method specifically includes the following steps:

[0068] S1. Ultrasonic atomization treatment is performed on the liquid metal to obtain metal droplets. Specifically, after connecting the ultrasonic nozzle to the generator to output ultrasonic energy, the liquid metal is injected into the ultrasonic nozzle through an injection pump, and metal droplets are obtained after ultrasonic atomization treatment. Under the action of ultrasonic waves, the liquid metal is broken into small droplets (spindle-shaped / dumbbell-shaped), as Figure 1 shown. The liquid metal is composed of a gallium-indium-tin ternary alloy;

[0069] S2. The metal droplets are dropped on the substrate by direct writing printing. The material of the substrate is silica gel to obtain a liquid metal conductive pattern.

[0070] In step S1, the frequency of the generator is 40 KHz and the power is 20 W; the flow rate of the injection pump is 0.2 ml / s, and the ultrasonic atomization time is 2 h;

[0071] In step S2, the dripping method is gas blowing, and the parameters of gas blowing are as follows: the gas is air, the air pressure is 0.5 KPa, and the deposition time is 5 s. At this time, the liquid droplets will form a conductive network with the deposition of time, as Figure 2 shown.

[0072] Example 3

[0073] The difference from Example 1 is only that in this example, the gallium-based liquid metal is a gallium-indium alloy, and the substrate types are human skin and leaves. Others are the same as Example 1 and will not be elaborated here, as Figure 3 shown.

[0074] Example 4

[0075] The difference from Example 1 is only that in this example, the gallium-based liquid metal is pure gallium, and the substrate type is cotton cloth. Others will not be elaborated here.

[0076] Example 5

[0077] The difference from Example 1 is only that the set ultrasonic frequency in this example is 60 KHz, and others are the same as Example 1 and will not be elaborated here.

[0078] Example 6

[0079] The difference from Example 1 is only that the ultrasonic frequency set in this example is 80 KHz, and the others are the same as those in Example 1, which will not be elaborated here.

[0080] Example 7

[0081] The difference from Example 1 is only that the ultrasonic frequency set in this example is 100 KHz, and the others are the same as those in Example 1, which will not be elaborated here.

[0082] Example 8

[0083] The difference from Example 1 is only that the ultrasonic frequency set in this example is 120 KHz, and the others are the same as those in Example 1, which will not be elaborated here.

[0084] In order to verify the conductivity of the liquid metal conductive film deposited after atomization (spraying) and whether it is conductive and stable under large tensile deformation, the liquid metal film prepared in Example 1 was tested, and the test results are as Figure 4 shown. When the prepared liquid metal conductive film was stretched by 0 - 700% respectively, the resistance change was small. When the circuit integrating multiple electronic components was stretched, etc., the light remained on (as Figure 5 shown), and the results showed that the prepared liquid metal conductive film had good conductivity and stable conductivity during stretching.

[0085] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A method for preparing a liquid metal conductive thin film, characterized in that, The preparation method specifically includes the following steps: S1. Perform ultrasonic atomization treatment on the liquid metal to obtain metal droplets; S2. Continuously drop the metal droplets onto the substrate. Two of the metal droplets fuse with each other to obtain a conductive unit. Multiple conductive units are connected to each other to obtain a conductive short chain. After multiple conductive short chains fuse and connect with each other, a liquid metal conductive thin film is finally obtained.

2. The method for preparing a liquid metal conductive thin film according to claim 1, characterized in that, In step S1, the liquid metal consists of a main component and a remaining component. The main component is selected from one of cesium, gallium, rubidium, potassium, sodium, indium, lithium, tin, bismuth, thallium, cadmium, lead, zinc, antimony, magnesium, aluminum and their alloys, and the remaining component is selected from at least one of iron-based single-metal, cobalt-based single-metal, nickel-based single-metal, copper-based single-metal, silver-based single-metal, multi-component magnetic metals, multi-component non-magnetic metals and solid non-metals.

3. The method for preparing a liquid metal conductive thin film according to claim 1, characterized in that, Step S1 specifically includes the following operations: Connect the ultrasonic nozzle to the generator and output ultrasonic energy. Inject the liquid metal into the ultrasonic nozzle through an injection pump, and obtain metal droplets after ultrasonic atomization treatment; and / or, the microscopic morphology of the metal droplets is dumbbell-shaped or spindle-shaped.

4. The method for preparing a liquid metal conductive thin film according to claim 3, characterized in that, The frequency of the generator is 1 - 200 KHz, and the power is 1 - 100 W; the flow rate of the injection pump is 0.01 - 20 ml / s, and the ultrasonic atomization time is 0.1 - 5 h.

5. The method for preparing a liquid metal conductive thin film according to claim 1, characterized in that, In step S2, the material of the substrate is one of a flexible material, an elastic material and a hard material, and the contact surface of the substrate is a plane or a curved surface.

6. The method for preparing a liquid metal conductive thin film according to claim 5, characterized in that, The flexible material is selected from one of a cloth-based material, a paper-based material, a PI film, a plastic film, a PET film, PVA, an animal, and a plant epidermis; the elastic material is selected from one of PDMS, silica gel, Ecoflex, SBS elastomer, POE elastomer, aliphatic aromatic random copolyester, rubber, resin, hydrogel, polyurethane, styrene block copolymer, PVC, polyimide, poly terephthalic acid plastics, polyethylene octene coelastomer, and thermoplastic elastomer; the hard material is selected from one of wood, PCB, FR4, polytetrafluoroethylene, silicon wafer, glass, and ITO.

7. The method for preparing a liquid metal conductive thin film according to claim 1, characterized in that, In step S2, the dropping method is selected from gravity dropping or gas blowing. The parameters of the gas blowing are as follows: the gas is selected from one of air, nitrogen, and argon, and the air pressure is 0.1 KPa - 5 MPa.

8. A liquid metal conductive thin film, characterized in that, Prepared by using any one of the preparation methods of claims 1 - 7.

9. A method for preparing a liquid metal conductive pattern, characterized in that, The preparation method specifically includes the following steps: S1. Perform ultrasonic atomization treatment on the liquid metal to obtain metal droplets; S2. Adopt a mask plate method, a 3D multi-axis printing method or a direct writing printing method to continuously drop the metal droplets onto the substrate. Two of the metal droplets fuse with each other to obtain a conductive unit. Multiple conductive units are connected to each other to obtain a conductive short chain. After multiple conductive short chains fuse and connect with each other, a liquid metal conductive pattern is finally obtained.

10. The method for preparing a liquid metal conductive pattern according to claim 9, characterized in that, In the step S1, the liquid metal is composed of a main component and a balance component. The main component is selected from one of cesium, gallium, rubidium, potassium, sodium, indium, lithium, tin, bismuth, thallium, cadmium, lead, zinc, antimony, magnesium, aluminum and their alloys, and the balance component is selected from at least one of iron-based single-metal, cobalt-based single-metal, nickel-based single-metal, copper-based single-metal, silver-based single-metal, multi-component magnetic metals, multi-component non-magnetic metals and solid non-metals.

11. The method for preparing a liquid metal conductive pattern according to claim 9, characterized in that, The step S1 specifically includes the following operations: Connect the ultrasonic nozzle to the generator to output ultrasonic energy, inject the liquid metal into the ultrasonic nozzle through a syringe pump, and obtain metal droplets after ultrasonic atomization treatment.

12. The method for preparing a liquid metal conductive pattern according to claim 9, characterized in that, The frequency of the generator is 1 - 200 KHz, and the power is 1 - 100 W; the flow rate of the syringe pump is 0.01 - 20 ml / s, and the ultrasonic atomization time is 0.1 - 5 h.

13. The method for preparing a liquid metal conductive pattern according to claim 9, characterized in that, In the step S2, the material of the substrate is one of a flexible material, an elastic material and a hard material, and the contact surface of the substrate is a plane or a curved surface.

14. The method for preparing a liquid metal conductive pattern according to claim 9, characterized in that, The flexible material is selected from one of cloth-based materials, paper-based, PI film, plastic film, PET film, PVA, animals, and plant epidermis; the elastic material is selected from one of PDMS, silica gel, Ecoflex, SBS elastomer, POE elastomer, aliphatic aromatic random copolyester, rubber, resin, hydrogel, polyurethane, styrene block copolymer, PVC, polyimide, poly terephthalic acid plastics, polyethylene octene co-elastomer, and thermoplastic elastomer; the hard material is selected from one of wood, PCB, FR4, polytetrafluoroethylene, silicon wafer, glass, and ITO.

15. The method for preparing a liquid metal conductive pattern according to claim 9, characterized in that, In the step S2, the dripping method is selected from gravity dripping or gas blowing. The parameters of the gas blowing are as follows: the gas is selected from one of air, nitrogen, and argon, and the air pressure is 0.1 KPa - 5 MPa.

16. A liquid metal conductive pattern, characterized in that, Prepared by using the preparation method according to any one of claims 9 - 15.

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