A stretchable flexible liquid metal pattern with antibacterial ability prepared based on laser technology and a preparation method and use thereof

Abstract

This invention provides a stretchable flexible liquid metal pattern with antibacterial properties prepared using laser technology, along with its preparation method and applications, belonging to the field of flexible sensors. The preparation method includes the following steps: Step 1: Prepare a suspension containing liquid metal / laser sensitizer, uniformly coat it onto the surface of a flexible polymer film, and activate the film surface using a laser to form an activated pattern in the activated area; Step 2: Rinse the film with a solvent, followed by chemical plating to obtain a polymer film with a metal pattern deposited in the activated area; then chemically plate the film with silver again; Step 3: Immerse the film in an acidic or alkaline solution, and coat the metal pattern with liquid metal to obtain the flexible liquid metal pattern. The flexible liquid metal pattern prepared using this invention exhibits good flexibility, excellent conductivity under bending and stretching conditions, and excellent antibacterial properties, showing promising application prospects in the field of flexible sensors.

Description

Technical Field

[0001] This invention belongs to the field of flexible sensors, specifically relating to a stretchable flexible liquid metal pattern with antibacterial capabilities prepared based on laser technology, its preparation method, and its applications. Background Technology

[0002] With the rapid development of electronics and nanoscience in my country, there is a growing demand for simplified, refined, and environmentally friendly manufacturing processes for electronic components. Acquiring potential signals in electronic components requires robust and stable electrode materials for long-term, precise acquisition and transmission. Traditional rigid circuit boards, which support and connect electronic components, crack when stretched, inevitably increasing their resistance. Therefore, they cannot simultaneously meet the requirements of high conductivity and high ductility, ultimately dictating the non-deformability of electronic devices. Stretchable flexible electrodes can create new interface structures during stretching, solving the problem of non-conductivity after stretching. They can also achieve precise and stable biosignal detection in complex environments, maintaining excellent and stable conductivity even under conditions of body deformation, temperature changes, and sweat immersion. Therefore, with societal development, lightweight and miniaturized flexible wearable devices are poised to become the next generation of electronic products.

[0003] Fabrication of flexible circuits is a prerequisite for the fabrication of flexible integrated circuits. Generally, conductive lines are created on a flexible substrate using copper plating or printing processes to complete the fabrication of the flexible circuit. The process flow for fabricating flexible circuits at low cost and high efficiency has been continuously optimized and explored. Liquid metals are safe and non-toxic, have high boiling points, good conductivity, and negligible vapor pressure, exhibiting properties as high as 10... 6 Liquid metals possess orders-of-magnitude conductivity and self-healing capabilities that allow for arbitrary deformation at room temperature. They can also be integrated into elastic substrates without altering the substrate's mechanical properties. Through selective wetting of the substrate, liquid metals can be used to fabricate various patterns to diversify electrode structures. The adhesion of liquid metals is crucial for obtaining stable electrodes. However, liquid metals exhibit a certain degree of fluidity and oxidize immediately in air. The high surface tension of the oxide layer makes it difficult to wet non-reactive surfaces, thus hindering patterning. In practical research, liquid metal circuit fabrication mainly falls into four categories: direct writing, parallel printing, molding and microfluidic injection, and intermetallic bond-assisted patterning. Intermetallic bond-assisted patterning, a reactive wetting behavior, is simpler and more convenient than the other three methods. It refers to the formation of intermetallic bonds between the liquid metal and another pre-patterned metal substrate, resulting in strong wetting behavior. Specifically, firstly, acid or alkaline solutions are used to remove surface oxides, then direct contact between the liquid metal and other metals is induced, leading to an intermetallic alloying reaction and obtaining highly adhesive liquid metal patterns.

[0004] Laser-activated selective metallization (LAM) is a micro / nano-fabrication tool that combines digital control, imaging recognition, and precision stages. It has gained widespread attention due to its mask-free operation, high precision, high efficiency, small heat-affected zone, selective sintering capability, and ability to reduce thermal damage to substrates. This technique involves first preparing a pre-patterned metal substrate using LAM, then patterning liquid metal onto the substrate using intermetallic bonding. This method overcomes many shortcomings of traditional liquid metal patterning methods and is of great significance for the large-scale fabrication of flexible electronic devices based on liquid metals.

[0005] The literature (Development of Flexible Circuits and Sensors Based on Patterned Liquid Metal, Master's Thesis, Guangdong University of Technology, 2021) reports a process for fabricating patterned liquid metal circuits based on laser technology. A CO2 infrared laser is used to ablate porous graphene on commercial polyimide (PI) film tape. Utilizing the rough microstructure of porous graphene, liquid metal can only be deposited on the relatively smooth, untreated areas, and cannot adhere to the PI-ablated graphene surface. The deposited pattern is then transferred to a flexible substrate and encapsulated to complete the fabrication of the flexible circuit. Demonstration with embedded surface-mount LEDs verifies that the fabricated flexible circuit exhibits good bending fit and stretchability.

[0006] However, liquid metal circuits fabricated using this process cannot achieve high precision; the resulting patterns or circuits have low resolution and cannot be used to create complex designs. Furthermore, the transfer of liquid metal to a flexible substrate using this process relies on the adhesion of the liquid metal to the substrate via oxides on the liquid metal surface—a physical adhesion with weak bonding. Therefore, conductivity decreases or even disappears under significant tensile strain, leading to circuit breaks. Thus, there is an urgent need to develop a flexible metal pattern that exhibits excellent conductivity under arbitrary bending conditions and large tensile strain conditions, and whose excellent antibacterial properties offer a potential application as a flexible bioelectronic sensor. Summary of the Invention

[0007] The purpose of this invention is to provide a stretchable flexible liquid metal pattern with antibacterial properties prepared based on laser technology, as well as its preparation method and applications.

[0008] This invention provides a method for preparing stretchable flexible liquid metal patterns with antibacterial properties based on laser technology, which includes the following steps:

[0009] Step 1: Add liquid metal to a solvent and disperse it evenly to obtain a liquid metal dispersion. Then add a laser sensitizer and mix evenly to obtain a liquid metal / laser sensitizer suspension. Coat the suspension evenly on the surface of a flexible polymer film and use a laser to activate the surface of the flexible polymer film coated with the suspension to form an activated pattern in the activated area.

[0010] Step 2: Rinse the flexible polymer film obtained in Step 1 after laser activation with solvent, and then perform chemical plating to obtain a polymer film with a metal pattern deposited in the activated area; then perform chemical silver plating on the film again to obtain a polymer film with a silver layer deposited on the metal pattern.

[0011] Step 3: Immerse the polymer film containing the metal pattern obtained in Step 2 into an acidic or alkaline solution, and coat the metal pattern with liquid metal to obtain a flexible liquid metal pattern.

[0012] Furthermore,

[0013] In step 1, the liquid metal gallium element and gallium-based alloy are one or both.

[0014] And / or, in step 1, the solvent is selected from one or more of the following: water, alcohol solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, chlorinated hydrocarbon solvents, phenolic solvents, acid solvents, ester solvents, amine solvents, ketone solvents, and ether solvents;

[0015] And / or, in step 1, the laser sensitizer is selected from one or more of the following: copper salts, copper oxides, copper hydroxides, organic copper complexes, chromium salts, chromium oxides, chromium hydroxides, manganese salts, manganese oxides, manganese hydroxides, iron salts, iron oxides, iron hydroxides, molybdenum salts, molybdenum oxides, molybdenum hydroxides, aluminum salts, aluminum oxides, aluminum hydroxides, bismuth salts, bismuth oxides, bismuth hydroxides, tin salts, tin oxides, tin hydroxides, antimony salts, antimony oxides, antimony hydroxides, zinc salts, zinc oxides, zinc hydroxides, tungsten salts, tungsten oxides, tungsten acids, neodymium salts, neodymium oxides, and neodymium hydroxides.

[0016] And / or, in step 1, the flexible polymer is one or more of the following: styrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, diene-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, ethylene-vinyl acetate copolymers, ethylene-acrylate copolymers, ionomers, acrylate-based thermoplastic elastomers, natural rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, brominated butyl rubber, silicone rubber, ethylene propylene diene monomer (EPDM) rubber, nitrile rubber, hydrogenated nitrile rubber, and chloroprene rubber.

[0017] And / or, in step 2, the solvent is selected from one or more of the following: water, alcohol solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, chlorinated hydrocarbon solvents, phenol solvents, acid solvents, ester solvents, amine solvents, ketone solvents, and ether solvents;

[0018] And / or, in step 2, the metal used in the electroless plating is a conductive metal;

[0019] And / or, in step 3, the liquid metal is one or both of elemental gallium and gallium-based alloys.

[0020] Furthermore,

[0021] In step 1, the gallium-based alloy is an alloy formed by gallium and at least one of the elements selected from indium, tin, zinc, and bismuth; preferably, it is one or more of the following: gallium-indium alloy, gallium-tin alloy, gallium-zinc alloy, gallium-indium-tin alloy, gallium-indium-zinc alloy, gallium-indium-tin-zinc alloy, or gallium-indium-tin-bismuth alloy.

[0022] And / or, in step 1, the alcohol solvent is one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, tert-butanol, and pentanol; and / or, the aromatic hydrocarbon solvent is one or more of toluene, xylene, butyltoluene, and vinyltoluene; and / or, the aliphatic hydrocarbon solvent is one or more of ethane, propane, butane, pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, heptane isomers, octane, and 2,2,4-trimethylpentane; and / or, the chlorinated hydrocarbon solvent is one or more of chloroform, dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene, trichloropropane, and dichloroethane; and / or, the phenolic solvent is phenol, cresol, ortho-... The solvent is selected from one or more of cresol, m-cresol, p-cresol, xylenol, and p-tert-butylphenol; and / or, the acid solvent is selected from one or more of formic acid, acetic acid, oxalic acid, propionic acid, acrylic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid; and / or, the ester solvent is selected from one or more of methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, and isoamyl formate; and / or, the amine solvent is selected from one or more of ethylenediamine, isopropylamine, ethanolamine, diethanolamine, butylamine, and dimethylethanolamine; and / or, the ketone solvent is selected from one or more of cyclohexanone, toluenecyclohexanone, acetone, methyl butyl ketone, and methyl isobutyl ketone; and / or, the ether solvent is selected from one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether.

[0023] And / or, in step 1, the styrene-based thermoplastic elastomer is selected from styrene-butadiene-styrene copolymer (SBS), polystyrene-isoprene-polystyrene copolymer (SIS), styrene-ethylene / propylene copolymer-styrene block copolymer (SEPS), or styrene-hydrogenated butadiene-styrene block copolymer (SEBS); and / or, the polyolefin-based thermoplastic elastomer is selected from polyolefin elastomer (POE) or thermoplastic vulcanizate (TPV); and / or, the diene-based thermoplastic elastomer is selected from trans-1,4-polybutadiene (TPB) or trans-... -1,4-Polyisoprene (TPI); and / or, the vinyl chloride thermoplastic elastomer is selected from polyvinyl chloride thermoplastic elastomer (TPVC) or chlorinated polyethylene elastomer (TCPE); and / or, the polyurethane thermoplastic elastomer is thermoplastic polyurethane elastomer (TPU); and / or, the polyester thermoplastic elastomer is thermoplastic polyester elastomer (TPEE); and / or, the polyamide thermoplastic elastomer is thermoplastic polyamide elastomer (TPAE); and / or, the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer (EVA);

[0024] And / or, in step 2, the alcohol solvent is one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, tert-butanol, and pentanol; and / or, the aromatic hydrocarbon solvent is one or more of toluene, xylene, butyltoluene, and vinyltoluene; and / or, the aliphatic hydrocarbon solvent is one or more of ethane, propane, butane, pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, heptane isomers, octane, and 2,2,4-trimethylpentane; and / or, the chlorinated hydrocarbon solvent is one or more of chloroform, dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene, trichloropropane, and dichloroethane; and / or, the phenolic solvent is phenol, cresol, ortho-... The solvent is selected from one or more of cresol, m-cresol, p-cresol, xylenol, and p-tert-butylphenol; and / or, the acid solvent is selected from one or more of formic acid, acetic acid, oxalic acid, propionic acid, acrylic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid; and / or, the ester solvent is selected from one or more of methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, and isoamyl formate; and / or, the amine solvent is selected from one or more of ethylenediamine, isopropylamine, ethanolamine, diethanolamine, butylamine, and dimethylethanolamine; and / or, the ketone solvent is selected from one or more of cyclohexanone, toluenecyclohexanone, acetone, methyl butyl ketone, and methyl isobutyl ketone; and / or, the ether solvent is selected from one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether.

[0025] And / or, in step 2, the conductive metal is selected from one or more of copper, silver, gold, chromium or nickel;

[0026] And / or, in step 3, the gallium-based alloy is an alloy formed by gallium and at least one of the elements selected from indium, tin, zinc, and bismuth; preferably, it is one or more of gallium-indium alloy, gallium-tin alloy, gallium-zinc alloy, gallium-indium-tin alloy, gallium-indium-zinc alloy, gallium-indium-tin-zinc alloy, or gallium-indium-tin-bismuth alloy.

[0027] Preferably,

[0028] The solvents used in steps 1 and 2 can be the same or different;

[0029] And / or, the liquid metals used in steps 1 and 3 can be the same or different.

[0030] Further, in step 3, the alkaline solution is one or more aqueous solutions of lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium hydroxide, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, hexamethylenediamine, decanediamine, diethylenetriamine, hexamethylenediamine, sodium methoxide, potassium ethoxide, potassium tert-butoxide, pyridine, triethylenetetramine, tetraethylenepentamine, urea, and ammonia.

[0031] The acidic solution is an aqueous solution of one or more of the following: hydrogen chloride, hydrogen bromide, hydrogen iodide, hydrogen fluoride, sulfuric acid, sulfurous acid, phosphoric acid, nitric acid, formic acid, acetic acid, propionic acid, acrylic acid, sulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, nitrous acid, pyruvic acid, oxalic acid, succinic acid, adipic acid, hydrobromic acid, boric acid, oxalic acid, tartaric acid, ascorbic acid, benzoic acid, salicylic acid, and citric acid.

[0032] Furthermore,

[0033] In step 1, the liquid metal / laser sensitizer suspension contains 0.3-10 wt% liquid metal and 0.3-10 wt% laser sensitizer by mass.

[0034] And / or, in step 3, the concentration of the alkaline solution is 0.01 mol / L to 5 mol / L; the concentration of the acidic solution is 0.01 mol / L to 5 mol / L.

[0035] Furthermore,

[0036] In step 1, the liquid metal is added to the solvent and then sonicated to ensure that the liquid metal is evenly dispersed.

[0037] And / or, in step 1, stir when adding the laser sensitizer;

[0038] And / or, in step 1, the wavelength of the laser is 190–1200 nm;

[0039] And / or, in step 2, the electroless plating temperature is 30–100°C and the time is 1–120 min;

[0040] And / or, in step 3, the method of coating the metal pattern with liquid metal is to brush the liquid metal onto the metal pattern.

[0041] Furthermore,

[0042] In step 1, the wavelength of the laser is 192nm, 355nm or 1064nm, the laser power is 1-10W, the laser scanning speed is 500-3000mm / s, and the laser frequency is 50-200kHz.

[0043] And / or, in step 3, the pattern includes circuits, decorative patterns, or graphics.

[0044] The present invention also provides a flexible liquid metal pattern, which is prepared by the aforementioned method.

[0045] The present invention also provides the use of the aforementioned flexible liquid metal pattern in the fabrication of flexible electronic devices.

[0046] The present invention also provides a flexible electronic device comprising the aforementioned flexible liquid metal pattern.

[0047] The flexible liquid metal pattern described in this invention can be a circuit diagram in a flexible electronic device, or it can be a decorative pattern or graphic.

[0048] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows:

[0049] (1) The preparation method of the present invention is simple and convenient. In traditional manufacturing methods, the flatbed printing method requires mask manufacturing and has weak adhesion to the substrate; the microfluidic injection patterning method also has limitations in mask design, template manufacturing and chip manufacturing. However, the preparation method of the present invention does not require mask manufacturing. The pattern can be designed directly by computer software. During the operation, the laser scans along the computer-designed route, which has high precision, is convenient to operate, and the reaction process and cost are easy to control, and has the prospect of large-scale industrial application.

[0050] (2) In the preparation method of the present invention, the liquid metal has a strong bonding force with the substrate. The patterning of the liquid metal is achieved by chemically reacting with the metal. Compared with the traditional flatbed printing method and transfer method, the liquid metal has a stronger adhesion force.

[0051] (3) The laser required by the preparation method of the present invention has low cost, is easy to maintain and operate.

[0052] (4) The liquid metal flexible pattern (or circuit) obtained by the preparation method of the present invention still has excellent conductivity under stretching and arbitrary bending angle, and can even light up a small light bulb under stretching deformation of 500%.

[0053] (5) The liquid metal flexible pattern (or circuit) obtained by the preparation method of the present invention is made by reacting with a metal substrate. When the metal substrate is copper or silver with antibacterial ability, it can endow the liquid metal flexible circuit with a certain antibacterial ability, thus making it better used as a biological flexible sensor.

[0054] In summary, this invention provides a stretchable flexible liquid metal pattern with antibacterial properties prepared using laser technology. The laser technology used in the preparation method of this invention features maskless operation, high precision, high efficiency, and a small heat-affected zone. The flexible liquid metal pattern prepared using this method exhibits good flexibility, can be bent and stretched at will, and displays excellent electrical conductivity under bending and stretching conditions, as well as excellent antibacterial properties, showing broad application prospects in the field of flexible biosensors.

[0055] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0056] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Detailed Implementation

[0057] The raw materials and equipment used in this invention are all known products, obtained by purchasing commercially available products.

[0058] The styrene-ethylene / propylene copolymer-styrene triblock copolymer (SEPS) was purchased from Kuraray Ltd. under the brand name HYBRAR. TM 7311F. Styrene-hydrogenated butadiene block copolymer (SEBS) was purchased from Sinopec Baling Petrochemical Company, grade YH-506. Thermoplastic polyurethane elastomer rubber (TPU) was purchased from BASF (China) Co., Ltd., grade 3096. Thermoplastic polyester elastomer (TPEE) was purchased from DuPont, USA, grade 4096. Polyolefin elastomer (POE) was purchased from ExxonMobil Chemical Company, USA, grade 6202.

[0059] Copper oxalate was purchased from Dazhan Jiyuan New Materials Technology Co., Ltd., tin dioxide was purchased from Xi'an Chemical Reagent Company, copper pyrophosphate was purchased from Dazhan Jiyuan New Materials Technology Co., Ltd., and basic copper phosphate was purchased from Dazhan Jiyuan New Materials Technology Co., Ltd.

[0060] Hydroiodic acid, acrylic acid, citric acid, phosphoric acid, hydrochloric acid, sodium carbonate, triethanolamine, ammonia, sodium bicarbonate, and sodium hydroxide were purchased from Chengdu Kelong Chemical Reagent Factory.

[0061] The electroless copper plating solution was purchased from Dazhan Jiyuan New Material Technology Co., Ltd., and the concentration of anhydrous copper sulfate in the solution was 6-12 g / L. The electroless silver plating solution was purchased from Weilan Technology Co., Ltd.

[0062] Various liquid metals, such as elemental gallium, gallium-indium alloy, gallium-tin alloy, gallium-indium-tin alloy, and gallium-indium-tin-zinc alloy, were purchased from Shenyang Jiabei Trading Co., Ltd.

[0063] Flatbed laser marking machine, model MF-EA, pulsed laser, maximum laser power 20W, laser wavelength 1064nm, Guangdong Han's Yueming Laser Group Co., Ltd.

[0064] Planar laser marking machine, model MUV-ER, pulsed laser, maximum laser power 5W, laser wavelength 355nm, Guangdong Han's Yueming Laser Group Co., Ltd.

[0065] Flat laser marking machine, model MV-U, pulsed laser, maximum laser power 2W, laser wavelength 192nm, Peak International Laser Company.

[0066] 3D laser marking machine, model MF-DA, pulsed laser, maximum laser power 20W, laser wavelength 1064nm, Guangdong Han's Yueming Laser Group Co., Ltd.

[0067] 3D laser marking machine, model MUV-E-3DR, pulsed laser, maximum laser power 5W, laser wavelength 355nm, made by Dida Laser Equipment Co., Ltd.

[0068] 3D laser marking machine, model MV-U3D, pulsed laser, maximum laser power 2W, laser wavelength 192nm, Peak International Laser Company.

[0069] Example 1

[0070] First, 3 wt.% liquid gallium was added to 100 mL of anhydrous ethanol and sonicated to obtain a uniform liquid metal dispersion. Then, 9 wt.% of basic copper phosphate, a laser sensitizer, was added while stirring, and the mixture was thoroughly mixed to obtain a suspension. This suspension was then uniformly coated onto the surface of a flexible TPU polymer film. The surface of the flexible polymer film coated with the liquid metal / basic copper phosphate suspension was activated using a near-infrared pulsed laser (wavelength 1064 nm) according to the desired pattern. The laser power was 10 W, the laser scanning speed was 3000 mm / s, and the laser frequency was 200 kHz. The sensitizer in unactivated areas of the film was washed away with anhydrous ethanol. The laser-activated flexible polymer was then immersed in a chemical copper plating solution and plated with copper at 60°C for 5 min to obtain a conductive copper pattern. Finally, the flexible polymer containing the copper pattern was immersed in a chemical silver plating solution and plated with silver at 50°C for 5 min to obtain a conductive copper / silver pattern. Finally, liquid gallium was brushed onto a flexible polymer film with a copper / silver pattern using a nylon brush in a 0.01 mol / L hydroiodic acid solution (acidic solution) to cover the pattern, thus obtaining a flexible liquid metal pattern.

[0071] Example 2

[0072] The liquid metal in the suspension is elemental gallium with a content of 6 wt.% and basic copper phosphate with a content of 6 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-indium alloy. The acidic solution is a 0.5 mol / L acrylic acid solution. Other conditions are the same as in Example 1.

[0073] Example 3

[0074] The liquid metal in the suspension is elemental gallium with a content of 4 wt.% and a basic copper phosphate content of 8 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-tin alloy. The acidic solution is a 1 mol / L citric acid solution. Other conditions are the same as in Example 1.

[0075] Example 4

[0076] The liquid metal in the suspension is elemental gallium with a content of 8 wt.% and a basic copper phosphate content of 4 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium indium tin alloy. The acidic solution is a 5 mol / L phosphoric acid solution. Other conditions are the same as in Example 1.

[0077] Example 5

[0078] The liquid metal in the suspension is elemental gallium with a content of 9 wt.% and a basic copper phosphate content of 3 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium indium tin zinc alloy. The acidic solution is a 1 mol / L hydrochloric acid solution. Other conditions are the same as in Example 1.

[0079] Example 6

[0080] First, 3 wt.% gallium-indium alloy was added to 100 mL of acetic acid and sonicated to obtain a uniform liquid metal dispersion. Then, 9 wt.% tin dioxide, a laser sensitizer, was added while stirring, and the mixture was thoroughly mixed to obtain a suspension. This suspension was then uniformly coated onto the surface of a flexible SEBS polymer film. The flexible polymer film coated with the liquid metal / tin dioxide suspension was activated using a near-infrared pulsed laser (wavelength 1064 nm) according to the desired pattern. The laser power was 6 W, the laser scanning speed was 1000 mm / s, and the laser frequency was 80 kHz. The sensitizer in unactivated areas of the film was washed away with acetic acid. The laser-activated flexible polymer was then immersed in a chemical copper plating solution and copper was plated at 65°C for 8 min to obtain a conductive copper pattern. Finally, the flexible polymer film containing the copper pattern was immersed in a chemical silver plating solution and silver was plated at 50°C for 10 min to obtain a conductive copper / silver pattern. Liquid gallium was brushed onto a flexible polymer film with a copper / silver pattern using a nylon brush in a 0.01 mol / L sodium carbonate solution (alkaline solution) to cover the pattern, thus obtaining a flexible liquid metal pattern.

[0081] Example 7

[0082] The liquid metal in the suspension is a gallium-indium alloy with a content of 6 wt.% and a tin dioxide content of 6 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-indium alloy. The alkaline solution is a 0.5 mol / L triethanolamine solution. Other conditions are the same as in Example 6.

[0083] Example 8

[0084] The liquid metal in the suspension is a gallium-indium alloy with a content of 4 wt.% and a tin dioxide content of 8 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-tin alloy. The alkaline solution is a 1 mol / L ammonia solution. Other conditions are the same as in Example 6.

[0085] Example 9

[0086] The liquid metal in the suspension is a gallium-indium alloy with a content of 8 wt.% and a tin dioxide content of 4 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-indium-tin alloy. The alkaline solution is a 5 mol / L sodium bicarbonate solution. Other conditions are the same as in Example 6.

[0087] Example 10

[0088] The liquid metal in the suspension is a gallium-indium alloy with a content of 9 wt.% and a tin dioxide content of 3 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-indium-tin-zinc alloy. The alkaline solution is a 1 mol / L sodium hydroxide solution. Other conditions are the same as in Example 6.

[0089] Example 11

[0090] First, 3 wt.% gallium-tin alloy was added to 100 mL of phenol and sonicated to obtain a uniform liquid metal dispersion. Then, 9 wt.% of the laser sensitizer, copper pyrophosphate, was added while stirring, and the mixture was thoroughly mixed to obtain a suspension. This suspension was then uniformly coated onto the surface of a flexible TPEE polymer film. The flexible polymer film coated with the liquid metal / copper pyrophosphate suspension was activated using a UV pulsed laser (wavelength 355 nm) according to the desired pattern. The laser power was 3 W, the laser scanning speed was 500 mm / s, and the laser frequency was 50 kHz. The sensitizer in the unactivated areas of the film was washed away with phenol. The laser-activated flexible polymer was then immersed in a chemical copper plating solution and copper was plated at 50°C for 20 min to obtain a conductive copper pattern. Finally, the flexible polymer containing the copper pattern was immersed in a chemical silver plating solution and silver was plated at 50°C for 15 min to obtain a conductive copper / silver pattern. Liquid gallium was brushed onto a flexible polymer film with a copper / silver pattern using a nylon brush in a 0.01 mol / L hydroiodic acid solution (acidic solution) to cover the pattern, thus obtaining a flexible liquid metal pattern.

[0091] Example 12

[0092] The liquid metal in the suspension was a gallium-tin alloy with a content of 6 wt.% and a copper pyrophosphate content of 6 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns was a gallium-indium alloy. The acidic solution was a 0.5 mol / L acrylic acid solution. Other conditions were the same as in Example 11.

[0093] Example 13

[0094] The liquid metal in the suspension is a gallium-tin alloy with a content of 4 wt.% and a copper pyrophosphate content of 8 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-tin alloy. The acidic solution is a 1 mol / L citric acid solution. Other conditions are the same as in Example 11.

[0095] Example 14

[0096] The liquid metal in the suspension is a gallium-tin alloy with a content of 8 wt.% and a copper pyrophosphate content of 4 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is a gallium-indium-tin alloy. The acidic solution is a 5 mol / L phosphoric acid solution. Other conditions are the same as in Example 11.

[0097] Example 15

[0098] The liquid metal in the suspension was a gallium-tin alloy with a content of 9 wt.% and a copper pyrophosphate content of 3 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns was a gallium-indium-tin-zinc alloy. The acidic solution was a 1 mol / L hydrochloric acid solution. Other conditions were the same as in Example 11.

[0099] Example 16

[0100] First, 3 wt.% gallium indium tin alloy was added to 100 mL of formic acid and sonicated to obtain a uniform liquid metal dispersion. Then, 9 wt.% of laser sensitizer copper oxalate was added while stirring, and the mixture was thoroughly mixed to obtain a suspension. This suspension was then uniformly coated onto the surface of a flexible POE polymer film. The flexible polymer film coated with the liquid metal / copper oxalate suspension was activated using a pulsed laser (wavelength 192 nm) according to the desired pattern. The laser power was 1.5 W, the laser scanning speed was 2000 mm / s, and the laser frequency was 100 kHz. Formic acid was used to wash away the sensitizer in the unactivated areas of the film. The laser-activated flexible polymer was then immersed in a chemical copper plating solution and plated with copper at 40°C for 110 min to obtain a conductive copper pattern. Finally, the flexible polymer containing the copper pattern was immersed in a chemical silver plating solution and plated with silver at 50°C for 20 min to obtain a conductive copper / silver pattern. Finally, liquid gallium was brushed onto a flexible polymer film with a copper / silver pattern using a nylon brush in a 0.01 mol / L sodium carbonate solution (alkaline solution) to cover the pattern, thus obtaining a flexible liquid metal pattern.

[0101] Example 17

[0102] The liquid metal in the suspension was gallium indium tin alloy with a content of 6 wt.% and copper oxalate content of 6 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns was gallium indium alloy. The alkaline solution was a 0.5 mol / L triethanolamine solution. Other conditions were the same as in Example 16.

[0103] Example 18

[0104] The liquid metal in the suspension is gallium indium tin alloy with a content of 4 wt.% and copper oxalate content of 8 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is gallium tin alloy. The alkaline solution is a 1 mol / L ammonia solution. Other conditions are the same as in Example 16.

[0105] Example 19

[0106] The liquid metal in the suspension is gallium indium tin alloy with a content of 8 wt.% and copper oxalate content of 4 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns is gallium indium tin alloy. The alkaline solution is a 5 mol / L sodium bicarbonate solution. Other conditions are the same as in Example 16.

[0107] Example 20

[0108] The liquid metal in the suspension was gallium indium tin alloy with a content of 9 wt.% and copper oxalate content of 3 wt.%. The liquid metal brushed onto the flexible polymer film with copper / silver patterns was gallium indium tin zinc alloy. The alkaline solution was a 1 mol / L sodium hydroxide solution. Other conditions were the same as in Example 16.

[0109] The following is the method for preparing the control sample.

[0110] Comparative Example 1

[0111] Only the laser sensitizer, basic copper phosphate, was added to the suspension; no liquid metal was added. Other conditions were the same as in Example 1.

[0112] Comparative Example 2

[0113] Only liquid metal was added to the suspension, without adding basic copper phosphate, and other conditions were the same as in Example 1.

[0114] Comparative Example 3

[0115] No liquid metal or basic copper phosphate was added to the suspension, and other conditions were the same as in Example 1.

[0116] Comparative Example 4

[0117] The amount of elemental gallium added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 1.

[0118] Comparative Example 5

[0119] The amount of basic copper phosphate added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 1.

[0120] Comparative Example 6

[0121] The amount of elemental gallium added to the suspension was 11 wt.%, and other conditions were the same as in Example 1.

[0122] Comparative Example 7

[0123] The amount of basic copper phosphate added to the suspension was 11 wt.%, and other conditions were the same as in Example 1.

[0124] Comparative Example 8

[0125] Only the laser sensitizer tin dioxide was added to the suspension, without adding liquid metal, and other conditions were the same as in Example 9.

[0126] Comparative Example 9

[0127] Only liquid metal was added to the suspension, without adding tin dioxide, and other conditions were the same as in Example 9.

[0128] Comparative Example 10

[0129] No liquid metal or tin dioxide was added to the suspension, and other conditions were the same as in Example 9.

[0130] Comparative Example 11

[0131] The amount of gallium-indium alloy added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 9.

[0132] Comparative Example 12

[0133] The amount of tin dioxide added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 9.

[0134] Comparative Example 13

[0135] The amount of gallium-indium alloy added to the suspension was 12 wt.%, and other conditions were the same as in Example 9.

[0136] Comparative Example 14

[0137] The amount of tin dioxide added to the suspension was 12 wt.%, and other conditions were the same as in Example 9.

[0138] Comparative Example 15

[0139] Only the laser sensitizer copper pyrophosphate was added to the suspension, without adding liquid metal, and other conditions were the same as in Example 12.

[0140] Comparative Example 16

[0141] Liquid metal was added to the suspension, but copper pyrophosphate was not added. Other conditions were the same as in Example 12.

[0142] Comparative Example 17

[0143] No liquid metal or copper pyrophosphate was added to the suspension, and other conditions were the same as in Example 12.

[0144] Comparative Example 18

[0145] The amount of gallium-tin alloy added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 12.

[0146] Comparative Example 19

[0147] The amount of copper pyrophosphate added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 12.

[0148] Comparative Example 20

[0149] The amount of gallium-tin alloy added to the suspension was 12 wt.%, and other conditions were the same as in Example 12.

[0150] Comparative Example 21

[0151] The amount of copper pyrophosphate added to the suspension was 12 wt.%, and other conditions were the same as in Example 12.

[0152] Comparative Example 22

[0153] Only the laser sensitizer copper oxalate was added to the suspension, without adding liquid metal, and other conditions were the same as in Example 18.

[0154] Comparative Example 23

[0155] Liquid metal was added to the suspension, but copper oxalate was not added. Other conditions were the same as in Example 18.

[0156] Comparative Example 24

[0157] No liquid metal or copper oxalate was added to the suspension, and other conditions were the same as in Example 18.

[0158] Comparative Example 25

[0159] The amount of gallium indium tin alloy added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 18.

[0160] Comparative Example 26

[0161] The amount of copper oxalate added to the suspension was 0.2 wt.%, and other conditions were the same as in Example 18.

[0162] Comparative Example 27

[0163] The amount of gallium indium tin alloy added to the suspension was 15 wt.%, and other conditions were the same as in Example 18.

[0164] Comparative Example 28

[0165] The amount of copper oxalate added to the suspension was 15 wt.%, and other conditions were the same as in Example 18.

[0166] Comparative Example 29

[0167] The final step involves brushing liquid metal into deionized water, with other conditions consistent with Example 1.

[0168] Comparative Example 30

[0169] The final step involves brushing liquid metal into deionized water, with other conditions consistent with Example 7.

[0170] Comparative Example 31

[0171] The final step involves brushing liquid metal into deionized water, with other conditions consistent with Example 13.

[0172] Comparative Example 32

[0173] The final step involves brushing liquid metal into deionized water, with other conditions consistent with Example 20.

[0174] Comparative Example 33

[0175] The final step involves brushing liquid metal into the air, with other conditions consistent with Example 1.

[0176] Comparative Example 34

[0177] The final step involves brushing liquid metal into the air, with other conditions consistent with Example 7.

[0178] Comparative Example 35

[0179] The final step involves brushing liquid metal into the air, with other conditions consistent with Example 13.

[0180] Comparative Example 36

[0181] The final step involves brushing liquid metal into the air, with other conditions consistent with Example 20.

[0182] Comparative Example 37

[0183] After silver plating, liquid metal is not brushed on, and other conditions are the same as in Example 1.

[0184] Comparative Example 38

[0185] After silver plating, liquid metal is not brushed on, and other conditions are the same as in Example 7.

[0186] Comparative Example 39

[0187] After silver plating, liquid metal was not brushed on, and other conditions were the same as in Example 13.

[0188] Comparative Example 40

[0189] After silver plating, liquid metal is not brushed on, and other conditions are the same as in Example 20.

[0190] Comparative Example 41

[0191] After copper plating, liquid metal was applied directly without silver plating, and other conditions were the same as in Example 1.

[0192] Comparative Example 42

[0193] After copper plating, liquid metal was applied directly without silver plating, and other conditions were the same as in Example 7.

[0194] Comparative Example 43

[0195] After copper plating, liquid metal was applied directly without silver plating, and other conditions were the same as in Example 13.

[0196] Comparative Example 44

[0197] After copper plating, liquid metal was applied directly without silver plating, and other conditions were the same as in Example 20.

[0198] The following specific experimental examples demonstrate the beneficial effects of the present invention.

[0199] Experimental Example 1: Bending resistance, tensile resistance and antibacterial properties test

[0200] 1. Experimental Methods

[0201] Bending resistance test: Connect the obtained flexible liquid metal pattern to a circuit with a small light bulb (rated voltage 2.5V; rated power approximately 0.6W). Test whether the light bulb lights up when the flexible liquid metal pattern is bent from 0° to 360°. If the light bulb goes out, it indicates poor conductivity of the circuit during bending; conversely, if the light bulb does not go out, it indicates good conductivity of the circuit during bending.

[0202] Tensile resistance test: Connect the obtained flexible liquid metal pattern to a circuit with a small light bulb (rated voltage 2.5V; rated power approximately 0.6W). Test whether the light bulb lights up when the flexible liquid metal pattern is stretched from 0% to 500%. If the light bulb goes out, it indicates poor conductivity during the stretching process; conversely, if the light bulb does not go out, it indicates good conductivity during the stretching process.

[0203] Antibacterial properties test: The "disc diffusion method" was used. The obtained flexible liquid metal pattern was cut into small discs with a diameter of 8 mm and placed in a petri dish coated with Escherichia coli or Staphylococcus aureus. After 24 hours, if no transparent inhibition zone was formed around the disc, it indicated that it had no antibacterial properties or weak antibacterial properties. Conversely, if a transparent inhibition zone was formed around the disc, it indicated that it had antibacterial properties. The larger the diameter of the transparent zone, the better the antibacterial performance.

[0204] In this experimental example, all liquid metal patterns used to test bending resistance are rectangular patterns with a length of 50 mm and a width of 2 mm, and the liquid metal patterns used to test stretching resistance are rectangular patterns with a length of 2 mm and a width of 1.5 mm.

[0205] 2. Experimental Results

[0206] The test results are shown in Table 1.

[0207] In the adhesion test: "Yes" indicates that the liquid metal can adhere to the substrate; "No" indicates that the liquid metal cannot adhere to the substrate at all.

[0208] In the selective test: "Yes" means that liquid metal can only selectively adhere to metal areas; "No" means that liquid metal can adhere to both areas with and without metal patterns, that is, it cannot selectively adhere to areas with metal and cannot form liquid metal patterns.

[0209] In bending / stretching resistance: "Yes" means the light bulb can be lit; "No" means the light bulb cannot be lit; "Weak" means the light bulb can be lit, but the light is weak due to the increased resistance.

[0210] In the antibacterial test: "Yes" indicates that a transparent inhibition zone is formed around the sample and is clearly visible to the naked eye, indicating a good antibacterial effect; "No" indicates that there is no transparent inhibition zone around the sample, indicating a poor or no antibacterial effect. In the adhesion test, "No" indicates that the liquid metal cannot adhere to the substrate and cannot form a liquid metal pattern, so the antibacterial test cannot be performed. In the selectivity test, "No" indicates that the liquid metal can adhere to both areas with and without metal patterns, that is, it cannot selectively adhere to areas with metal and cannot form a liquid metal pattern, so the antibacterial test was not performed.

[0211] In Table 1, the "-" in the performance test results indicates that liquid metal coating was not performed, or that liquid metal did not have the ability to selectively adhere to the polymer film surface, so no further testing was conducted.

[0212] Table 1. Performance test results of various liquid metal patterns

[0213]

[0214]

[0215]

[0216]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223] As shown in Table 1, Examples 1 to 20 all achieved the fabrication of flexible liquid metal patterns on the surface of a flexible polymer film coated with a laser absorber by using various polymers, different types of laser sensitizers, suspensions prepared in different proportions, acidic or alkaline solutions, and liquid metal. Furthermore, the resulting flexible liquid metal patterns exhibited good conductivity under bending conditions, enabling the small light bulb to light up. Under tensile conditions, although different materials had different elongations at break, the light bulb maintained high brightness throughout the stretching process. In the antibacterial test, a transparent antibacterial ring appeared near the disc, indicating that the flexible liquid metal pattern possesses antibacterial capabilities.

[0224] Comparative Examples 1–28 investigated the effects of the laser sensitizer and liquid metal content on the final results, demonstrating that the laser sensitizer plays a major role as a laser absorber in the laser-induced electroless plating process. When the laser sensitizer content was below 0.3 wt.%, laser activation could not generate sufficient active seeds to induce copper electroless plating, resulting in the inability to deposit metal patterns. When the content of either the liquid metal or the laser sensitizer was above 10 wt.%, a thick coating would form on the polymer surface, preventing the laser from reaching the substrate surface, leading to poor adhesion between the metal and the substrate and the inability to form a complete metal pattern. In the case of pure liquid metal and without the addition of a laser absorber, after laser activation, metal patterns could not be deposited during electroless copper and silver plating, and selective adhesion of liquid metal was also unsuccessful. While using a single laser sensitizer or liquid metal with a content below 0.3 wt.% can successfully allow liquid metal to adhere, the adhesion is weak, leading to increased resistance during stretching and a decrease in the brightness of the bulb. However, when using both a laser sensitizer and liquid metal, the adhesion between the liquid metal and the metal substrate is much stronger, allowing the bulb to maintain high brightness throughout the stretching process. Therefore, adding liquid metal to the laser sensitizer to enhance its laser activation effect is essential in the method of this invention.

[0225] Comparative Examples 29-32 involved brushing liquid metal into deionized water, while Comparative Examples 33-36 involved brushing liquid metal into air. It can be seen that when brushing liquid metal into air and deionized water, the liquid metal can adhere simultaneously to both metallic and non-metallic areas of the polymer film surface, lacking selective adhesion characteristics; therefore, the liquid metal cannot be patterned. However, in acidic or alkaline solutions, the liquid metal can only selectively adhere to areas with metallic patterns on the polymer film surface, and cannot adhere to non-metallic areas. Therefore, acidic or alkaline solutions are essential in the method of this invention.

[0226] Comparative Examples 37-40, after silver plating without brushing with liquid metal, revealed that although silver has a certain conductivity, as a solid metal, bending causes the silver layer to break, leading to increased resistance and reduced brightness of the light bulb. Under stretching, the high tensile strength directly causes the silver layer to break, breaking the circuit and preventing the light bulb from lighting up. At the same time, due to the presence of the silver layer, the samples were still able to form a transparent inhibition zone in the petri dish during the antibacterial experiment, indicating that it has good antibacterial ability.

[0227] Comparative Examples 41-44 show that after copper plating, liquid metal was applied directly without silver plating. Even without a silver layer, the liquid metal selectively adhered to the copper layer. However, the circuit obtained without silver plating did not produce a clear transparent inhibition zone in the antibacterial experiment, indicating that the sample lacked antibacterial ability or had weak antibacterial ability. This also proves the presence of the silver layer, which is an essential component for applying this metal pattern or circuit to antibacterial biosensors.

[0228] In summary, this invention provides a stretchable flexible liquid metal pattern with antibacterial properties fabricated using laser technology. The laser technology used in the fabrication method of this invention features maskless operation, high precision, high efficiency, and a small heat-affected zone. The flexible liquid metal pattern prepared using this method exhibits good flexibility, can be bent and stretched at will, and displays excellent electrical conductivity under bending and stretching conditions, as well as excellent antibacterial properties, showing broad application prospects in the field of flexible biosensors.

Claims

1. A method for preparing stretchable flexible liquid metal patterns with antibacterial properties based on laser technology, characterized in that: It includes the following steps: Step 1: Add liquid metal to a solvent and disperse it evenly to obtain a liquid metal dispersion. Then add a laser sensitizer and mix evenly to obtain a liquid metal / laser sensitizer suspension. Coat the suspension evenly on the surface of a flexible polymer film and use a laser to activate the surface of the flexible polymer film coated with the suspension to form an activated pattern in the activated area. The liquid metal is one or two of elemental gallium and gallium-based alloys; the laser sensitizer is selected from one or more of the following: copper salts, copper oxides, copper hydroxides, organic copper complexes, chromium salts, chromium oxides, chromium hydroxides, manganese salts, manganese oxides, manganese hydroxides, iron salts, iron oxides, iron hydroxides, molybdenum salts, molybdenum oxides, molybdenum hydroxides, aluminum salts, aluminum oxides, aluminum hydroxides, bismuth salts, bismuth oxides, bismuth hydroxides, tin salts, tin oxides, tin hydroxides, antimony salts, antimony oxides, antimony hydroxides, zinc salts, zinc oxides, zinc hydroxides, tungsten salts, tungsten oxides, tungsten acid, neodymium salts, neodymium oxides, and neodymium hydroxides; in the liquid metal / laser sensitizer suspension, the mass percentage of the liquid metal is 0.3~10 wt%, and the mass percentage of the laser sensitizer is 0.3~10 wt%. Step 2: Rinse the laser-activated flexible polymer film obtained in Step 1 with a solvent, and then perform chemical plating to obtain a polymer film with a metal pattern deposited in the activated area; then perform chemical plating on the film again to obtain a polymer film with a silver layer deposited on the metal pattern; the metal used in the chemical plating is a conductive metal; the conductive metal is selected from one or more of copper, silver, gold, chromium or nickel; Step 3: Immerse the polymer film containing the metal pattern obtained in Step 2 into an acidic or alkaline solution, and coat the metal pattern with liquid metal to obtain a flexible liquid metal pattern; the concentration of the alkaline solution is 0.01 mol / L-5 mol / L; the concentration of the acidic solution is 0.01 mol / L-5 mol / L; the liquid metal is one or both of elemental gallium and gallium-based alloys.

2. The method according to claim 1, characterized in that: In step 1, the solvent is selected from one or more of the following: water, alcohol solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, chlorinated hydrocarbon solvents, phenol solvents, acid solvents, ester solvents, amine solvents, ketone solvents, and ether solvents. And / or, in step 1, the flexible polymer is one or more of the following: styrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, diene-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, ethylene-vinyl acetate copolymers, ethylene-acrylate copolymers, ionomers, acrylate-based thermoplastic elastomers, natural rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, brominated butyl rubber, silicone rubber, ethylene propylene diene monomer (EPDM) rubber, nitrile rubber, hydrogenated nitrile rubber, and chloroprene rubber. And / or, in step 2, the solvent is selected from one or more of the following: water, alcohol solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, chlorinated hydrocarbon solvents, phenol solvents, acid solvents, ester solvents, amine solvents, ketone solvents, and ether solvents.

3. The method according to claim 2, characterized in that: In step 1, the gallium-based alloy is an alloy formed by gallium and at least one element selected from indium, tin, zinc, and bismuth; And / or, in step 1, the alcohol solvent is one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, tert-butanol, and pentanol; and / or, the aromatic hydrocarbon solvent is one or more of toluene, xylene, butyltoluene, and vinyltoluene; and / or, the aliphatic hydrocarbon solvent is one or more of ethane, propane, butane, pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, heptane isomers, octane, and 2,2,4-trimethylpentane; and / or, the chlorinated hydrocarbon solvent is one or more of chloroform, dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene, trichloropropane, and dichloroethane; and / or, the phenolic solvent is phenol, cresol, ortho-... The solvent is selected from one or more of cresol, m-cresol, p-cresol, xylenol, and p-tert-butylphenol; and / or, the acid solvent is selected from one or more of formic acid, acetic acid, oxalic acid, propionic acid, acrylic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid; and / or, the ester solvent is selected from one or more of methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, and isoamyl formate; and / or, the amine solvent is selected from one or more of ethylenediamine, isopropylamine, ethanolamine, diethanolamine, butylamine, and dimethylethanolamine; and / or, the ketone solvent is selected from one or more of cyclohexanone, toluenecyclohexanone, acetone, methyl butyl ketone, and methyl isobutyl ketone; and / or, the ether solvent is selected from one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether. And / or, in step 1, the styrene-based thermoplastic elastomer is selected from styrene-butadiene-styrene copolymer, polystyrene-isoprene-polystyrene copolymer, styrene-ethylene / propylene copolymer-styrene block copolymer, or styrene-hydrogenated butadiene-styrene block copolymer; and / or, the polyolefin-based thermoplastic elastomer is selected from polyolefin elastomers or thermoplastic vulcanizates; and / or, the diene-based thermoplastic elastomer is selected from trans-1,4-polybutadiene or trans-1,4-polyisoprene; and / or, the vinyl chloride-based thermoplastic elastomer is selected from polyvinyl chloride thermoplastic elastomers or chlorinated polyethylene elastomers; and / or, the polyurethane-based thermoplastic elastomer is a thermoplastic polyurethane elastomer; and / or, the polyester-based thermoplastic elastomer is a thermoplastic polyester elastomer; and / or, the polyamide-based thermoplastic elastomer is a thermoplastic polyamide elastomer; and / or, the ethylene-vinyl acetate copolymer is an ethylene-vinyl acetate copolymer. And / or, in step 2, the alcohol solvent is one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, tert-butanol, and pentanol; and / or, the aromatic hydrocarbon solvent is one or more of toluene, xylene, butyltoluene, and vinyltoluene; and / or, the aliphatic hydrocarbon solvent is one or more of ethane, propane, butane, pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, heptane isomers, octane, and 2,2,4-trimethylpentane; and / or, the chlorinated hydrocarbon solvent is one or more of chloroform, dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene, trichloropropane, and dichloroethane; and / or, the phenolic solvent is phenol, cresol, ortho-... The solvent is selected from one or more of cresol, m-cresol, p-cresol, xylenol, and p-tert-butylphenol; and / or, the acid solvent is selected from one or more of formic acid, acetic acid, oxalic acid, propionic acid, acrylic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid; and / or, the ester solvent is selected from one or more of methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, and isoamyl formate; and / or, the amine solvent is selected from one or more of ethylenediamine, isopropylamine, ethanolamine, diethanolamine, butylamine, and dimethylethanolamine; and / or, the ketone solvent is selected from one or more of cyclohexanone, toluenecyclohexanone, acetone, methyl butyl ketone, and methyl isobutyl ketone; and / or, the ether solvent is selected from one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether. And / or, in step 3, the gallium-based alloy is an alloy formed by gallium and at least one element selected from indium, tin, zinc, and bismuth.

4. The method according to claim 3, characterized in that: In step 1, the gallium-based alloy is one or more of gallium-indium alloy, gallium-tin alloy, gallium-zinc alloy, gallium-indium-tin alloy, gallium-indium-zinc alloy, gallium-indium-tin-zinc alloy, or gallium-indium-tin-bismuth alloy.

5. The method according to claim 3, characterized in that: In step 3, the gallium-based alloy is one or more of gallium-indium alloy, gallium-tin alloy, gallium-zinc alloy, gallium-indium-tin alloy, gallium-indium-zinc alloy, gallium-indium-tin-zinc alloy, or gallium-indium-tin-bismuth alloy.

6. The method according to claim 3, characterized in that: The solvents used in steps 1 and 2 can be the same or different; And / or, the liquid metals used in steps 1 and 3 can be the same or different.

7. The method according to claim 1, characterized in that: In step 3, the alkaline solution is one or more aqueous solutions of lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium hydroxide, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, hexamethylenetetramine, sodium methoxide, potassium ethoxide, potassium tert-butoxide, pyridine, triethylenetetramine, tetraethylenepentamine, urea, and ammonia. The acidic solution is an aqueous solution of one or more of the following: hydrogen chloride, hydrogen bromide, hydrogen iodide, hydrogen fluoride, sulfuric acid, sulfurous acid, phosphoric acid, nitric acid, formic acid, acetic acid, propionic acid, acrylic acid, sulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, nitrous acid, pyruvic acid, oxalic acid, succinic acid, adipic acid, hydrobromic acid, boric acid, oxalic acid, tartaric acid, ascorbic acid, benzoic acid, salicylic acid, and citric acid.

8. The method according to any one of claims 1 to 7, characterized in that: In step 1, the liquid metal is added to the solvent and then sonicated to ensure that the liquid metal is evenly dispersed. And / or, in step 1, stir when adding the laser sensitizer; And / or, in step 1, the wavelength of the laser is 190~1200nm; And / or, in step 2, the temperature of the electroless plating is 30~100℃ and the time is 1~120min; And / or, in step 3, the method of coating the metal pattern with liquid metal is to brush the liquid metal onto the metal pattern.

9. The method according to claim 8, characterized in that: In step 1, the wavelength of the laser is 192 nm, 355 nm or 1064 nm, the laser power is 1-10W, the laser scanning speed is 500-3000 mm / s, and the laser frequency is 50-200 kHz. And / or, in step 3, the pattern includes circuits, decorative patterns, or graphics.

10. A flexible liquid metal pattern, characterized in that: It is prepared by the method described in any one of claims 1 to 9.

11. Use of the flexible liquid metal pattern of claim 10 in the fabrication of flexible electronic devices.

12. A flexible electronic device, characterized in that: It comprises the flexible liquid metal pattern as described in claim 10.

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