A method of manufacturing a magnetic resonance enhancing metamaterial

Abstract

The application relates to a manufacturing method of a magnetic resonance enhanced metamaterial, which comprises the following steps: providing a prefabricated metamaterial unit array comprising a plurality of prefabricated unit structures; each prefabricated unit structure comprises a three-dimensional flow channel structure; filling the three-dimensional flow channel structure with liquid metal to obtain a plurality of semi-finished metamaterials; and processing each semi-finished metamaterial to obtain a magnetic resonance enhanced metamaterial. By using the prefabricated three-dimensional flow channel structure and filling the liquid metal, the electromagnetic performance of the metamaterial can be effectively improved. The liquid metal filling method can simplify the manufacturing process of the metamaterial, compared with the traditional process, the number of processing and assembling links is reduced, thereby improving the production efficiency, ensuring the processing precision and consistency, and reducing the manufacturing cost. The semi-finished metamaterial is processed to ensure the stability and reliability of the liquid metal in the three-dimensional flow channel structure. The closed processing can prevent the liquid metal from leaking and ensure the performance stability of the metamaterial in the long-term use.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic resonance imaging, and in particular to a manufacturing method of a magnetic resonance enhancement metamaterial. BACKGROUND

[0002] MRI (Magnetic Resonance Imaging) technology is widely used in clinical medicine, and its advantages are non-invasive, no ionizing radiation, high tissue contrast and multi-parameter imaging capability, so it has attracted widespread attention. In the MRI system, the signal-to-noise ratio (SNR) is a key factor to determine the image quality, which directly affects the resolution, imaging efficiency and diagnostic accuracy of the image. Therefore, improving the signal-to-noise ratio to enhance the imaging performance of MRI has always been an important direction of research in this field.

[0003] In recent years, electromagnetic metamaterials have shown significant potential in improving the signal-to-noise ratio of MRI systems. Metamaterials can interact with the radio frequency magnetic field of the MRI system in a specific way, shaping, focusing and enhancing the radio frequency magnetic field without changing the existing hardware configuration of the MRI device. By improving the signal-to-noise ratio in the local area, it is usually placed as additional hardware in the imaging area of the subject to optimize the radio frequency field distribution and thus improve the image quality.

[0004] However, the preparation process of traditional MRI enhancement metamaterials cannot guarantee the processing precision and consistency. SUMMARY

[0005] Therefore, it is necessary to provide a manufacturing method of a magnetic resonance enhancement metamaterial capable of improving the processing precision and consistency in view of the above technical problems.

[0006] In a first aspect, the present application provides a manufacturing method of a magnetic resonance enhancement metamaterial, which comprises:

[0007] providing a pre-prepared metamaterial unit array; the pre-prepared metamaterial unit array comprises a plurality of pre-prepared unit structures, each pre-prepared unit structure comprising a three-dimensional flow channel structure;

[0008] filling each three-dimensional flow channel structure with liquid metal to obtain a plurality of semi-finished metamaterials;

[0009] processing each semi-finished metamaterial to obtain a magnetic resonance enhancement metamaterial.

[0010] In one of the embodiments, the above-mentioned filling each three-dimensional flow channel structure with liquid metal to obtain a plurality of semi-finished metamaterials comprises:

[0011] resin removal and curing treatment is performed on each three-dimensional flow channel structure;

[0012] Injecting liquid metal into each three-dimensional flow channel structure by using a first injector to obtain a semi-finished product metamaterial.

[0013] In one embodiment, the resin removal and curing treatment of each three-dimensional flow channel structure includes:

[0014] Injecting anhydrous ethanol into each three-dimensional flow channel structure by using a second injector; the anhydrous ethanol is used to remove residual resin in the three-dimensional flow channel structure.

[0015] Performing light curing and heat curing treatment on each three-dimensional flow channel structure.

[0016] In one embodiment, the processing of each semi-finished product metamaterial to obtain a magnetic resonance enhanced metamaterial includes:

[0017] Processing each semi-finished product metamaterial with a predetermined material to obtain a magnetic resonance enhanced metamaterial; the processing includes one of silicone sealing treatment and circuit connection treatment.

[0018] In one embodiment, the predetermined material includes silicone, and the processing of each semi-finished product metamaterial with the predetermined material to obtain a magnetic resonance enhanced metamaterial includes:

[0019] Injecting silicone into the flow channel opening of each semi-finished product metamaterial to perform silicone sealing treatment and obtain a magnetic resonance enhanced metamaterial.

[0020] In one embodiment, the predetermined material includes metal wires, and the processing of each semi-finished product metamaterial with the predetermined material to obtain a magnetic resonance enhanced metamaterial includes:

[0021] Inserting metal wires into the flow channel opening of each semi-finished product metamaterial to perform circuit connection treatment and obtain a magnetic resonance enhanced metamaterial.

[0022] In one embodiment, the preparation process of the three-dimensional flow channel structure includes:

[0023] Placing liquid resin in a resin tank;

[0024] Performing light curing treatment on the liquid resin based on a predetermined pattern to obtain a three-dimensional flow channel structure.

[0025] In one embodiment, the number of turns of the three-dimensional flow channel structure corresponds to the static magnetic field strength of magnetic resonance imaging.

[0026] In one embodiment, the static magnetic field strength of magnetic resonance imaging includes low field, high field and ultra-high field, and the method further includes:

[0027] Resonance response measurement and processing of the magnetic resonance enhancement metamaterial under the conditions of low-field magnetic resonance, high-field magnetic resonance and ultra-high-field magnetic resonance, obtaining measurement results, and adjusting the number of turns or structure of the three-dimensional flow channel according to the measurement results to process the magnetic resonance enhancement metamaterial under different magnetic resonance field strengths.

[0028] In one of the embodiments, the method further comprises:

[0029] The magnetic resonance enhancement metamaterial is subjected to radio frequency magnetic field enhancement factor simulation processing to obtain simulation results, and the simulation results include a two-dimensional distribution graph and a one-dimensional line graph of the radio frequency magnetic field enhancement factor.

[0030] The manufacturing method of the magnetic resonance enhancement metamaterial includes providing a pre-prepared metamaterial unit array including a plurality of pre-prepared unit structures; each pre-prepared unit structure includes a three-dimensional flow channel structure; filling the three-dimensional flow channel structure with liquid metal to obtain a plurality of semi-finished metamaterials; and processing each semi-finished metamaterial to obtain a magnetic resonance enhancement metamaterial. By using the pre-prepared three-dimensional flow channel structure and filling it with liquid metal, the electromagnetic performance of the metamaterial can be effectively improved. The use of liquid metal filling can simplify the manufacturing process of the metamaterial, reduce multiple processing and assembly steps compared to traditional processes, improve production efficiency, ensure processing precision and consistency, and reduce manufacturing costs. Processing the semi-finished metamaterial ensures the stability and reliability of the liquid metal in the three-dimensional flow channel structure. The sealing process prevents liquid metal leakage and ensures the stability of the metamaterial performance during long-term use. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Flowchart of the manufacturing method of the magnetic resonance enhancement metamaterial in one embodiment;

[0032] Figure 2 Example diagram of the metamaterial unit array obtained in one embodiment;

[0033] Figure 3 Front view of the pre-prepared unit structure in one embodiment;

[0034] Figure 4 Sectional view of the pre-prepared unit structure in one embodiment;

[0035] Figure 5 Flowchart of the process of obtaining the semi-finished metamaterial in one embodiment;

[0036] Figure 6 Flowchart of the resin removal and curing process in one embodiment;

[0037] Figure 7 Flowchart of the preparation process of the three-dimensional flow channel structure in one embodiment;

[0038] Figure 8 Simulation of resonance characteristics for one embodiment;

[0039] Figure 9 Measurement results of resonance response experiments for one embodiment;

[0040] Figure 10a One of the simulation results of magnetic resonance enhanced metamaterial for one embodiment;

[0041] Figure 10b Another of the simulation results of magnetic resonance enhanced metamaterial for one embodiment;

[0042] Figure 10c Third of the simulation results of magnetic resonance enhanced metamaterial for one embodiment;

[0043] Figure 11 Overall process flow chart for fabricating metamaterial unit mold for one embodiment. DETAILED DESCRIPTION

[0044] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0045] First, before specifically introducing the technical solutions of the embodiments of the present application, the technical background on which the embodiments of the present application are based is introduced.

[0046] Magnetic resonance imaging (MRI) technology is widely used in clinical medicine, and its advantages are non-invasive, no ionizing radiation, high tissue contrast and multi-parameter imaging capability, so it has attracted widespread attention. In the MRI system, signal-to-noise ratio (SNR) is a key factor to determine the image quality, which directly affects the resolution, imaging efficiency and diagnostic accuracy of the image. Therefore, improving the signal-to-noise ratio to enhance the imaging performance of MRI has always been an important direction of research in this field.

[0047] In recent years, electromagnetic metamaterials have shown significant potential in improving the signal-to-noise ratio of MRI systems. Metamaterials are spatially periodic resonant structures designed by humans, which can interact with the radio frequency magnetic field of the MRI system in a specific way. By shaping, focusing and enhancing the radio frequency magnetic field, the signal-to-noise ratio of the local area can be improved without changing the existing hardware configuration of the MRI device. Usually, such metamaterials are placed in the imaging area of the subject as additional hardware to optimize the radio frequency field distribution and thus improve the image quality.

[0048] However, as an artificial material, the performance of metamaterials is highly dependent on the design of the structure. The preparation process of traditional MRI-enhancing metamaterials mainly includes copper wire winding, copper foil cutting, and printed circuit board (PCB) processing technologies. These traditional processes face multiple challenges when processing complex or irregular three-dimensional structures, including difficulty in ensuring processing accuracy and consistency, and the need to consume more time or manpower. These limitations directly limit the flexibility of structure design and the potential for performance optimization of metamaterials in MRI applications.

[0049] Based on this, the application provides a manufacturing method of a magnetic resonance-enhancing metamaterial, aiming to solve the above technical problems.

[0050] In an exemplary embodiment, as shown in Figure 1 The application provides a manufacturing method of a magnetic resonance-enhancing metamaterial, comprising the following steps:

[0051] S101, providing a pre-prepared metamaterial unit array.

[0052] As shown in Figure 2 , the pre-prepared metamaterial unit array includes a plurality of pre-prepared unit structures 1010, as shown in Figure 3 and Figure 4 Each pre-prepared unit structure 1010 includes a three-dimensional flow channel structure 1011. The three-dimensional flow channel structure 1011 is filled with liquid metal 1012.

[0053] In the application, the pre-prepared metamaterial unit array is an ordered arrangement composed of a plurality of pre-prepared unit structures. Each pre-prepared unit structure contains a three-dimensional flow channel structure. The three-dimensional flow channel structure here is a channel with a specific shape and size for containing liquid metal. The three-dimensional flow channel structure can be made by precise 3D printing. By precisely controlling the size and shape of the flow channel, the distribution of liquid metal can be precisely controlled, thereby optimizing the electromagnetic properties of the metamaterial.

[0054] Further, according to the requirements of magnetic resonance imaging, the shape, size and arrangement of the pre-prepared unit structure are designed. Computer-aided design software can be used for design, and a pre-prepared metamaterial unit mold can be manufactured by microfabrication technology.

[0055] S102, filling the three-dimensional flow channel structure with liquid metal to obtain a plurality of semi-finished metamaterials.

[0056] The liquid metal is a metal or alloy that is in a liquid state at room temperature, with good electrical conductivity and flowability.

[0057] In the embodiments of the present application, a suitable liquid metal is selected and filled into the three-dimensional flow channel structure of the prefabricated unit structure by capillary action or pressure injection, etc. The filling process needs to ensure that the liquid metal completely fills the flow channel and there are no bubbles or impurities. The prefabricated unit structure after filling becomes a semi-finished metamaterial, and the liquid metal structure generates a specific induced magnetic field under electromagnetic excitation, providing a basis for magnetic resonance enhancement.

[0058] Further, according to the requirements of magnetic resonance enhancement, a suitable liquid metal is selected. Considering factors such as electrical conductivity, fluidity, stability, etc., the prefabricated metamaterial unit mold is placed in a vacuum environment to remove air and impurities in the flow channel. Then, the liquid metal is filled into the three-dimensional flow channel structure using capillary action or pressure injection, etc. The filling process needs to be slow to ensure that the liquid metal completely fills the flow channel and no bubbles are generated. X-ray or CT or other detection equipment can be used to monitor the filling process to ensure the filling quality.

[0059] S103, processing each semi-finished metamaterial to obtain a magnetic resonance enhancement metamaterial.

[0060] The processing is to ensure the stability and reliability of the liquid metal in the metamaterial. Encapsulation materials such as polymers, ceramics, etc. can be used to seal the semi-finished metamaterial. The encapsulation material needs to have good insulation, mechanical strength and chemical stability to prevent liquid metal leakage and oxidation. Processing can use injection molding, spraying, deposition, etc. according to the specific material and process requirements. The final magnetic resonance enhancement metamaterial has good electromagnetic properties and stability, which can effectively enhance the magnetic resonance signal and improve the imaging quality.

[0061] Further, a suitable encapsulation material such as polymer or ceramic is selected. The encapsulation material is heated to a molten state, and then covered on the semi-finished metamaterial by injection molding, spraying or deposition, etc. to form a sealed shell. The encapsulation material needs to have good insulation, mechanical strength and chemical stability to prevent liquid metal leakage and oxidation. The encapsulated metamaterial can be further processed and treated, such as polishing, etc. to improve its surface quality and appearance.

[0062] The manufacturing method of the above-mentioned magnetic resonance enhancement metamaterial comprises the following steps: providing a prefabricated metamaterial unit array comprising a plurality of prefabricated unit structures; each prefabricated unit structure comprises a three-dimensional flow channel structure; filling the three-dimensional flow channel structure with liquid metal to obtain a plurality of semi-finished metamaterials; and processing each semi-finished metamaterial to obtain a magnetic resonance enhancement metamaterial. By using prefabricated three-dimensional flow channel structures and filling them with liquid metal, the electromagnetic performance of the metamaterial can be effectively improved. The use of liquid metal filling can simplify the manufacturing process of the metamaterial, reduce the number of processing and assembly steps compared to traditional processes, improve production efficiency, ensure processing precision and consistency, and reduce manufacturing costs. Processing the semi-finished metamaterial ensures the stability and reliability of the liquid metal in the three-dimensional flow channel structure. Sealing treatment can prevent liquid metal leakage and ensure the stability of the performance of the metamaterial during long-term use.

[0063] In one exemplary embodiment, based on the above embodiment, see Figure 5 The embodiment of the present application relates to the process of metal filling treatment of each prefabricated unit structure to obtain a semi-finished metamaterial, comprising the following steps:

[0064] S201, resin removal and curing treatment of the three-dimensional flow channel structure.

[0065] Three-dimensional flow channel structure: It is a key part of the prefabricated unit structure, which is a channel with a specific shape and size for containing liquid metal to achieve specific electromagnetic properties. It is usually manufactured by microfabrication techniques such as photolithography, etching, etc. to form three-dimensional flow channels on the substrate material. These flow channels can be complex in shape to meet different magnetic resonance enhancement requirements.

[0066] Resin removal: During the manufacturing of prefabricated unit structures, resin materials may be used for auxiliary processing or support. Before metal filling, these resins need to be removed completely to ensure that the liquid metal can fill the flow channel smoothly and not be affected by resin impurities. Chemical solvent cleaning, high-temperature baking, etc. can be used to remove the resin.

[0067] Curing treatment: After resin removal, the three-dimensional flow channel structure is subjected to curing treatment to improve its mechanical strength and stability. Curing can be done by heating, ultraviolet irradiation, etc. to make the flow channel structure material more solid, which can withstand subsequent metal filling and processing.

[0068] Specifically, if heating curing method is used, the prefabricated unit structure can be placed in an oven and heated at a certain temperature for a period of time. The heating temperature and time are determined according to the material of the flow channel structure and the curing requirements. For materials that can be cured by ultraviolet light, the prefabricated unit structure can be irradiated by ultraviolet light to make the material cure quickly.

[0069] S202, using a first syringe, injecting liquid metal into the three-dimensional flow channel structure to obtain a semi-finished super material.

[0070] First syringe: a tool specially used for precise injection of liquid metal. It usually has a high-precision injection control mechanism, which can accurately control the amount and speed of injected liquid metal. The needle of the first syringe needs to match the inlet of the three-dimensional flow channel structure to ensure that the liquid metal can be smoothly injected into the flow channel without leakage.

[0071] Liquid metal: in this embodiment, liquid metal is a metal or alloy that is in liquid state at room temperature, with good electrical conductivity and flowability. For example, gallium-indium alloy is selected to fill the three-dimensional flow channel structure to achieve the specific electromagnetic properties of the magnetic resonance enhanced super material. When injecting liquid metal, it needs to be done slowly and uniformly to avoid generating bubbles or uneven filling.

[0072] Specifically, a suitable first syringe is selected to ensure that its needle matches the size of the inlet of the three-dimensional flow channel structure. The liquid metal is sucked into the first syringe, and the needle is inserted into the inlet of the three-dimensional flow channel structure. Slowly push the piston of the syringe to uniformly inject the liquid metal into the flow channel. The generation of bubbles and uneven filling can be avoided by controlling the injection speed and pressure. Observe the filling of the liquid metal to ensure that the flow channel is completely filled with liquid metal.

[0073] The resin removal and curing process of the three-dimensional flow channel structure in the embodiments of the present application ensures the cleanliness and stability of the three-dimensional flow channel structure, providing a good foundation for the uniform filling of liquid metal. Using the first syringe to inject liquid metal can achieve precise control and uniform filling, improving the quality and performance stability of the semi-finished super material.

[0074] In an exemplary embodiment, based on the above embodiments, see Figure 6 The embodiments of the present application relate to the process of removing and curing resin from the three-dimensional flow channel structure, comprising the following steps:

[0075] S301, using a second syringe, injecting anhydrous ethanol into the three-dimensional flow channel structure.

[0076] Among them, the second syringe: similar to the first syringe in the previous embodiment, the second syringe is also a tool for precise injection of liquid. It can be selected in different specifications and models according to different processing needs. In the embodiments of the present application, the second syringe is used to inject anhydrous ethanol to remove residual resin in the three-dimensional flow channel structure.

[0077] Anhydrous ethanol: A commonly used organic solvent with good solubility and volatility. In this embodiment, anhydrous ethanol is used to dissolve and remove residual resin in the three-dimensional flow channel structure. Since anhydrous ethanol is easily volatile at room temperature, it can be quickly removed after treatment without adversely affecting subsequent process steps.

[0078] During the manufacturing process of the pre-unit structure, some residual resin may remain in the three-dimensional flow channel structure. These residual resins will affect the filling effect of liquid metal and the performance of metamaterials, so they need to be removed. Residual resin may come from auxiliary materials or incomplete removal of resin components during the manufacturing process.

[0079] In the embodiments of the present application, a suitable second syringe is selected to ensure that its needle can be smoothly inserted into the inlet of the three-dimensional flow channel structure. Anhydrous ethanol is sucked into the second syringe, and the needle is inserted into the inlet of the three-dimensional flow channel structure. Slowly push the piston of the syringe to inject anhydrous ethanol into the flow channel. The pre-unit structure can be gently shaken during the injection process to ensure that the anhydrous ethanol can fully contact and dissolve the residual resin. Wait for a period of time to allow the anhydrous ethanol to fully dissolve the residual resin. Then, tilt or invert the pre-unit structure to allow the anhydrous ethanol dissolved with residual resin to flow out of the flow channel. The injection and outflow process can be repeated until the residual resin in the flow channel is completely removed.

[0080] S302, the three-dimensional flow channel structure is subjected to light curing and heat curing treatment.

[0081] Light curing: A method that uses ultraviolet light or other specific wavelength light to initiate chemical reactions, allowing materials to quickly solidify. In this embodiment, light curing can be used to preliminarily solidify the three-dimensional flow channel structure, improving its mechanical strength and stability. Light curing usually requires the use of specific light curing equipment and photoinitiators to ensure the solidification effect.

[0082] Heat curing: A method of achieving solidification by heating to cause chemical reactions in materials. Heat curing can further improve the solidification degree of the three-dimensional flow channel structure, enhancing its mechanical properties and durability. The temperature and time of heat curing need to be adjusted according to the characteristics of the material and the solidification requirements.

[0083] In the embodiments of the present application, the pre-unit structure treated with anhydrous ethanol is placed in a light curing device. The light curing device usually includes ultraviolet light source, reflector and sample stage, etc. Turn on the ultraviolet light source and irradiate the pre-unit structure. The irradiation time and intensity need to be adjusted according to the characteristics of the material and the solidification requirements. During the irradiation process, the position of the pre-unit structure can be adjusted appropriately to ensure that the ultraviolet light can uniformly irradiate all parts of the flow channel structure.

[0084] Place the pre-fabricated unit structure that has undergone light curing into an oven for thermal curing. The temperature and time of the oven need to be adjusted according to the characteristics of the material and the curing requirements. Generally speaking, the temperature of thermal curing will be higher than that of light curing to ensure that the material can be fully cured. During the process of thermal curing, the degree of curing of the pre-fabricated unit structure can be checked periodically to determine whether the curing time needs to be extended or the curing temperature needs to be adjusted.

[0085] The application embodiment adopts anhydrous ethanol injection treatment, which can effectively remove residual resin in the three-dimensional flow channel structure, improve the filling effect of liquid metal and the performance of the metamaterial. The light curing and thermal curing treatment can further improve the curing degree of the three-dimensional flow channel structure, enhance its mechanical strength and durability, and thus improve the stability and reliability of the metamaterial.

[0086] In one exemplary embodiment, based on the above embodiment, the application embodiment relates to a process of processing each semi-finished metamaterial to obtain a magnetic resonance enhanced metamaterial, specifically comprising: processing each semi-finished metamaterial with a preset material to obtain a magnetic resonance enhanced metamaterial.

[0087] Among them, the processing includes one of silica gel sealing treatment and circuit connection treatment.

[0088] The preset material refers to a specific material specially used for sealing the semi-finished metamaterial. These materials should have good sealing property, mechanical strength and chemical stability to ensure that they can effectively prevent the leakage of liquid metal in the magnetic resonance environment, while not affecting the electromagnetic performance of the metamaterial. For example, high molecular polymers, ceramic materials, metal alloys, etc. can be selected as the preset material. Different preset materials have different characteristics and application ranges, which can be selected according to specific needs.

[0089] Processing process: first, clean and pretreat the semi-finished metamaterial to remove impurities and contaminants on the surface. Then, according to the characteristics of the preset material and the processing requirements, select the appropriate sealing processing method. Common sealing processing methods include injection molding, spraying, deposition, welding, etc. For example, if a high molecular polymer is selected as the preset material, the polymer can be injected around the semi-finished metamaterial by injection molding to form a sealed shell. If a ceramic material is selected, a ceramic coating can be formed on the surface of the semi-finished metamaterial by spraying or deposition. If a metal alloy is selected, metal alloy sheets or wires can be welded at the flow channel openings of the semi-finished metamaterial. During the sealing processing, processing parameters such as temperature, pressure, speed, etc. need to be strictly controlled to ensure that the preset material can uniformly cover the surface of the semi-finished metamaterial to form a complete and sealed structure.

[0090] Selecting the preset material:

[0091] According to the performance requirements and use environment of the magnetic resonance enhanced metamaterial, a suitable preset material is selected. For example, if the metamaterial needs to have good flexibility and impact resistance, a high molecular polymer such as polyurethane, silicone rubber, etc. can be selected. If the metamaterial needs to have high mechanical strength and high temperature resistance, a ceramic material such as alumina, zirconia, etc. can be selected. If the metamaterial needs to have good electrical conductivity and electromagnetic shielding performance, a metal alloy such as copper alloy, aluminum alloy, etc. can be selected.

[0092] Pre-treatment of semi-finished metamaterial:

[0093] The semi-finished metamaterial is cleaned to remove surface dirt, dust and other impurities. Solvent cleaning and other methods can be used for cleaning.

[0094] The semi-finished metamaterial is surface treated to improve the bonding force between the preset material and the semi-finished metamaterial. For example, plasma treatment, chemical etching and other methods can be used to activate the surface of the semi-finished metamaterial.

[0095] Select the closed processing process: according to the characteristics and processing requirements of the preset material, select the appropriate closed processing method. For example, if a high molecular polymer is selected as the preset material, an injection molding method can be used. The high molecular polymer particles are heated and melted, and then the melted polymer is injected into the mold through the injection molding machine. The shape of the mold matches the shape of the semi-finished metamaterial. During the injection molding process, the injection pressure, temperature and speed parameters need to be controlled to ensure that the polymer can uniformly fill around the semi-finished metamaterial to form a sealed shell.

[0096] If a ceramic material is selected as the preset material, a spraying or deposition method can be used. The spraying method is to mix the ceramic powder with the binder, and then spray the mixed powder on the surface of the semi-finished metamaterial through the spray gun to form a ceramic coating. The deposition method is to form a ceramic film on the surface of the semi-finished metamaterial by physical vapor deposition or chemical vapor deposition. During the spraying or deposition process, parameters such as powder particle size, spraying distance, deposition temperature, etc. need to be controlled to ensure the quality and performance of the ceramic coating or film.

[0097] The preset material is used to process and treat the semi-finished metamaterial in the embodiments of the present application, which can effectively prevent the leakage of liquid metal and improve the stability and reliability of the metamaterial. Different preset materials can endow the metamaterial with different properties and characteristics to meet different application requirements.

[0098] In an exemplary embodiment, based on the above embodiment, the preset material of the embodiment of the application includes silica gel, and the preset material is used to process each semi-finished metamaterial to obtain a magnetic resonance enhanced metamaterial, specifically including: injecting silica gel into the flow channel opening of each semi-finished metamaterial to perform silica gel sealing treatment, thereby obtaining a magnetic resonance enhanced metamaterial.

[0099] In the embodiment, a suitable silica gel material is selected, which should have good fluidity and curing performance, so as to be able to be smoothly injected into the flow channel opening of the semi-finished metamaterial and cured to form a sealing structure under certain conditions.

[0100] The processing process is as follows: first, the semi-finished metamaterial to be sealed is prepared, and the flow channel opening thereof is ensured to be clean and free of impurities. Then, a suitable silica gel injection device such as a syringe, a glue filling machine, etc. is selected. The silica gel material is loaded into the injection device, and the injection parameters such as injection pressure, speed, etc. are adjusted. Then, the needle of the injection device is aimed at the flow channel opening of the semi-finished metamaterial, and the silica gel is slowly injected into the flow channel opening. During the injection process, the filling condition of the silica gel is observed to ensure that the silica gel can fully fill the flow channel opening and there is no bubble and gap. When the flow channel opening is completely filled with silica gel, the semi-finished metamaterial is placed in a suitable environment for curing according to the curing characteristics of the silica gel. The curing time and conditions can be adjusted according to the type and use instructions of the silica gel. After curing, the magnetic resonance enhanced metamaterial is obtained.

[0101] In the embodiment of the application, the silica gel has good flexibility and sealing performance, can effectively prevent liquid metal leakage, and improves the stability and reliability of the metamaterial. The injection process of the silica gel is simple and easy to operate, and can be operated by using a syringe, a glue filling machine, etc., and is suitable for large-scale production and application. The curing time and conditions of the silica gel can be adjusted as needed to meet different production process requirements. The magnetic resonance enhanced metamaterial processed by the silica gel has good mechanical strength and high temperature resistance, and can work stably for a long time in a magnetic resonance environment.

[0102] In an exemplary embodiment, based on the above embodiment, the preset material of the embodiment of the application includes metal wires, and the preset material is used to process each semi-finished metamaterial to obtain a magnetic resonance enhanced metamaterial, specifically including: inserting the metal wires into the flow channel opening of each semi-finished metamaterial to perform circuit connection treatment, thereby obtaining a magnetic resonance enhanced metamaterial.

[0103] Metal wires are typically made of highly conductive metal materials such as copper, aluminum, and silver. In this embodiment, a suitable metal wire is selected, with a diameter that matches the size of the flow channel opening of the semi-finished metamaterial to ensure a tight insertion and a good seal. The metal wire should also possess a certain degree of flexibility and mechanical strength to resist breakage during insertion.

[0104] Processing process: First, prepare the semi-finished metamaterial that needs to be sealed, ensuring that its flow channel opening is clean and free of impurities. Then, select a suitable metal wire and cut or bend it according to the size and shape of the flow channel opening so that it can be smoothly inserted into the flow channel opening. Next, use a tool to carefully insert the metal wire into the flow channel opening of the semi-finished metamaterial, ensuring the insertion depth is appropriate and that the metal wire is in close contact with the inner wall of the flow channel. After the metal wire is inserted, further fixing and sealing can be performed as needed, such as using glue, welding, etc. to fix the metal wire to the semi-finished metamaterial to prevent the metal wire from falling off. Finally, the magnetic resonance enhanced metamaterial is obtained.

[0105] In the embodiment of the present application, the opening of the flow channel is sealed by silicone, or copper wires are inserted into the inlet and outlet of the flow channel to connect the liquid metal to the external copper structure or copper circuit, thereby completing the final processing of the metamaterial unit.

[0106] In an exemplary embodiment, based on the above embodiment, see Figure 7 The preparation process of the three-dimensional flow channel structure of the embodiment of the present application includes the following steps:

[0107] S401, placing liquid resin in a resin tank.

[0108] Liquid resin: Liquid resin is a material with specific chemical composition and physical properties that solidifies under specific conditions to form a solid structure. In this embodiment, the selected liquid resin should have good fluidity, photocurability, and mechanical strength. For example, a photocurable resin can be selected that rapidly solidifies under ultraviolet light or light of a specific wavelength.

[0109] Resin tank: A container for liquid resin. Its material should be chemically stable and non-reactive. The shape and size of the resin tank can be designed based on the desired three-dimensional flow channel structure.

[0110] In the embodiments of the present application, a suitable liquid resin is selected, and factors such as the flowability, curing speed, and mechanical strength of the resin are considered according to the performance requirements of the three-dimensional flow channel structure. Some preliminary tests can be performed to determine the optimal resin type and parameters. A resin tank is prepared, and a suitable material such as glass or stainless steel is selected to ensure that the resin tank is clean and dry. The size and shape of the resin tank are determined according to the size of the three-dimensional flow channel structure to be prepared. The liquid resin is slowly injected into the resin tank to avoid the generation of bubbles and impurities. An injector, funnel, or other tool can be used for injection, and the liquid level of the resin is appropriately adjusted to facilitate the photocuring process.

[0111] S402, performing photocuring treatment on the liquid resin based on the preset pattern to obtain a three-dimensional flow channel structure.

[0112] The preset pattern is a specific pattern designed according to the required three-dimensional flow channel structure. It can be designed using computer-aided design software and converted into a format that can be recognized by the photocuring equipment. The preset pattern should include information such as the shape, size, and connection method of the flow channel.

[0113] Photocuring treatment: Photocuring treatment is a process that uses light of a specific wavelength to irradiate liquid resin, causing it to undergo a chemical reaction and solidify. In the embodiments of the present application, photocuring equipment such as ultraviolet lithography machines or digital light processing equipment can be used to perform photocuring treatment on the liquid resin. The photocuring equipment emits light of a specific wavelength based on the preset pattern, irradiating the liquid resin so that the resin in the irradiated area rapidly solidifies, while the unirradiated area remains in a liquid state. By performing photocuring treatment point by point or layer by layer, a three-dimensional flow channel structure can be gradually constructed.

[0114] In the embodiments of the present application, the preset pattern is imported into the photocuring equipment, and the settings and adjustments are made according to the operation instructions of the equipment. The light source intensity, exposure time, resolution, and other parameters of the photocuring equipment are ensured to meet the requirements. The photocuring equipment is started to perform photocuring treatment on the liquid resin. Based on the preset pattern, the photocuring equipment irradiates the liquid resin point by point or layer by layer, causing the resin in the irradiated area to solidify. The precision and quality of the three-dimensional flow channel structure can be adjusted by controlling parameters such as the movement speed and exposure frequency of the photocuring equipment. During the photocuring process, the curing of the resin should be observed, and the parameters should be adjusted in a timely manner to ensure the integrity and accuracy of the three-dimensional flow channel structure.

[0115] The embodiments of the present application use photocuring treatment to achieve high-precision three-dimensional flow channel structure preparation, meeting the precision requirements of the magnetic resonance enhancement metamaterial for flow channel structures. Photocuring treatment is fast, which can greatly shorten the preparation time and improve production efficiency.

[0116] In an example embodiment, based on the above embodiment, the number of turns of the three-dimensional flow channel structure of the embodiment of the application has a corresponding relationship with the static magnetic field strength of magnetic resonance imaging.

[0117] As shown in Figure 8 , the process structure design of the metamaterial unit under multiple static magnetic field strengths and the simulation of the resonant characteristics thereof. According to the demand for resonant frequency under different static magnetic field strengths, the flow channel design is optimized to match the hydrogen nuclear Larmor frequency under a specific static magnetic field. By adjusting the number of turns of the flow channel while keeping the overall size of the metamaterial unit unchanged, the resonant frequency of the metamaterial can be matched with the Larmor frequency of the hydrogen nucleus under a given static magnetic field condition. Specifically, the design features of the metamaterial unit include: the main radius of the precisely 3D-printed flow channel 1011 torus is 15 mm, and the tube radius is 1.6 mm; the number of turns of the liquid metal flow channel around the main radius is between 2 and 12 turns. This design enables the metamaterial flow channel to cover the hydrogen nuclear Larmor frequency under different static magnetic field strengths, including the following cases:

[0118] 1) Low-field MRI: the static magnetic field strength ranges from 0.25 to 1.0 Tesla (T), and the hydrogen nuclear Larmor frequency ranges from 10.6 to 42.6 megahertz (MHz). Under the design features of the above metamaterial unit, the number of turns of the liquid metal flow channel is about 9 to 12 turns.

[0119] 2) High-field MRI: the static magnetic field strength ranges from 1.0 to 4.0 Tesla (T), and the hydrogen nuclear Larmor frequency ranges from 42.6 to 170.4 megahertz (MHz). Under the design features of the above metamaterial unit, the number of turns of the liquid metal flow channel is about 4 to 8 turns.

[0120] 3) Ultra-high-field MRI: the static magnetic field strength is greater than 4.0 Tesla (T), and the hydrogen nuclear Larmor frequency is greater than 170.4 megahertz (MHz). Under the design features of the above metamaterial unit, the number of turns of the liquid metal flow channel is about 2 to 3 turns.

[0121] By determining the corresponding relationship between the number of turns of the three-dimensional flow channel structure and the static magnetic field strength of magnetic resonance imaging, the embodiment of the application can optimize the design of the three-dimensional flow channel structure according to the specific application requirements to obtain the best magnetic resonance enhancement effect.

[0122] In an example embodiment, based on the above embodiment, the static magnetic field strength of magnetic resonance imaging of the embodiment of the application includes low field, high field and ultra-high field, and the method of the embodiment of the application further comprises the following steps: under the conditions of low-field magnetic resonance, high-field magnetic resonance and ultra-high-field magnetic resonance, respectively, the resonant response measurement of the magnetic resonance enhancement metamaterial is processed to obtain the measurement results, and the number of turns or the structure of the three-dimensional flow channel is adjusted according to the measurement results to process the magnetic resonance enhancement metamaterial under different magnetic resonance field strengths.

[0123] The measurement results include resonance characteristics of the metamaterial samples under different field strengths, as shown in Figure 9 The results can reflect that the MRI-enhancing metamaterials suitable for different MRI field strengths can be processed by adjusting the number of turns or the structure of the three-dimensional flow channel.

[0124] The embodiment of the application first prepares a series of metamaterial samples with different numbers of three-dimensional flow channel structures. A vector network analyzer and a test antenna device are prepared and calibrated and debugged. Computer simulation is performed to simulate the magnetic resonance response of the three-dimensional flow channel structure with different numbers of turns under different field strengths. The metamaterial samples with different numbers of turns are tested using a vector network analyzer and a test antenna. According to the predetermined measurement scheme, the resonance response of each sample is measured, and the measurement results are recorded.

[0125] In the embodiment of the application, the measurement results are sorted and analyzed, and the relationship curve between the resonance response and the number of turns under different field strengths is drawn. By comparing the measurement results and the simulation results, the number of turns with the best magnetic resonance enhancement effect under different field strengths is found. According to the specific application requirements, the cost, performance and other factors are considered to determine the final number of turns of the three-dimensional flow channel structure.

[0126] In an exemplary embodiment, based on the above embodiment, the process of the method of the application specifically includes: performing radio frequency magnetic field enhancement factor simulation processing on the magnetic resonance enhancement metamaterial to obtain simulation results; as shown in Figure 10a , 10b and 10c. The simulation results include a two-dimensional distribution map of the radio frequency magnetic field enhancement factor and a corresponding one-dimensional line graph along the red line in the two-dimensional graph. The results show that the radio frequency magnetic field in the region of interest near the metamaterial is significantly enhanced by about 20 to 25 times. This enhancement effect ensures that the metamaterial unit can significantly improve the signal strength in low-field, high-field and ultra-high-field MRI applications, thereby optimizing the imaging effect.

[0127] In an exemplary embodiment, based on the above embodiment, the overall process flow chart for manufacturing the metamaterial unit mold is as shown in Figure 11 The method of the embodiment of the application specifically includes the following steps:

[0128] Step 1: Determine the number of turns of the three-dimensional flow channel structure;

[0129] Step 2: Place the liquid resin in the resin tank; perform light curing treatment on the liquid resin based on a predetermined pattern to obtain a three-dimensional flow channel structure; provide a prefabricated metamaterial unit mold including the three-dimensional flow channel structure;

[0130] Step 3: using the second syringe, each three-dimensional flow channel structure is treated with ethanol injection; ethanol is used to remove residual resin in the three-dimensional flow channel structure; each three-dimensional flow channel structure is treated with light curing and heat curing;

[0131] Step 4: using the first syringe, liquid metal is injected into each three-dimensional flow channel structure to obtain each semi-finished product super material;

[0132] Step 5: silica gel is injected into the flow channel opening of each semi-finished product super material for silica gel sealing treatment to obtain a magnetic resonance enhanced super material; or a metal wire is inserted into the flow channel opening of each semi-finished product super material for circuit connection treatment to obtain a magnetic resonance enhanced super material.

[0133] It should be understood that, although each step in the flowchart involved in each embodiment as described above is displayed in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, there is no strict order limitation for the execution of these steps, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in each embodiment as described above can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least part of other steps or steps or stages in other steps.

[0134] Each technical feature of the above embodiments can be combined arbitrarily, and in order to make the description concise, not all possible combinations of each technical feature in the above embodiments are described, however, as long as the combination of these technical features does not exist contradictory, it should be considered as the scope of the present application.

[0135] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A method for manufacturing a magnetic resonance enhanced metamaterial, characterized in that: The method comprises: Providing a prefabricated metamaterial unit array; the prefabricated metamaterial unit array includes a plurality of prefabricated unit structures, each of the prefabricated unit structures includes a three-dimensional flow channel structure; Liquid metal is used to fill each of the three-dimensional flow channel structures to obtain a plurality of semi-finished metamaterials; the number of turns of the three-dimensional flow channel structure corresponds to the static magnetic field strength of magnetic resonance imaging; the static magnetic field strength of magnetic resonance imaging includes low field, high field and ultra-high field; Resonant response measurements are performed on the magnetic resonance enhanced metamaterial under low-field magnetic resonance, high-field magnetic resonance, and ultra-high-field magnetic resonance conditions, obtaining measurement results, and adjusting the number of turns or structure of the three-dimensional flow channel according to the measurement results to produce magnetic resonance enhanced metamaterials under different magnetic resonance field strengths; Processing each of the semi-finished metamaterials to obtain a magnetic resonance enhanced metamaterial; The radio frequency magnetic field enhancement multiple simulation process is performed on the magnetic resonance enhanced metamaterial to obtain a simulation result; the simulation result includes a two-dimensional distribution diagram and a one-dimensional line diagram of the radio frequency magnetic field enhancement multiple.

2. The method according to claim 1, characterized in that The three-dimensional flow channel structures are filled with liquid metal to obtain a plurality of semi-finished metamaterials, including: performing resin removal and curing treatment on each of the three-dimensional flow channel structures; A first syringe is used to inject liquid metal into each of the three-dimensional flow channel structures to obtain each of the semi-finished metamaterials.

3. The method according to claim 2, characterized in that The resin removal and curing treatment of each of the three-dimensional flow channel structures includes: Using a second syringe, injecting anhydrous ethanol into each of the three-dimensional flow channel structures; the anhydrous ethanol is used to remove residual resin in the three-dimensional flow channel structure; Performing light curing and heat curing treatment on each of the three-dimensional flow channel structures.

4. The method according to claim 1, wherein The processing of each of the semi-finished metamaterials to obtain a magnetic resonance enhanced metamaterial comprises: The semi-finished metamaterials are processed with preset materials to obtain magnetic resonance enhanced metamaterials; the processing includes one of a silicone sealing process and a circuit connection process.

5. The method according to claim 4, characterized in that The preset material includes silica gel, and the semi-finished metamaterials are processed using the preset material to obtain the magnetic resonance enhanced metamaterial, including: The silica gel is injected into the flow channel opening of each semi-finished metamaterial to perform silica gel sealing treatment to obtain the magnetic resonance enhanced metamaterial.

6. The method according to claim 4, characterized in that The preset material includes a metal wire, and the semi-finished metamaterials are processed using the preset material to obtain the magnetic resonance enhanced metamaterial, including: The metal wire is inserted into the flow channel opening of each semi-finished metamaterial to perform circuit connection processing to obtain a magnetic resonance enhanced metamaterial.

7. The method according to claim 2, characterized in that The preparation process of the three-dimensional flow channel structure includes: Place liquid resin in the resin tank; The liquid resin is photocured based on a preset pattern to obtain the three-dimensional flow channel structure.

8. The method according to claim 1, characterized in that The liquid metal includes: a metal or alloy that is liquid at room temperature.

9. The method according to claim 1, characterized in that The method of filling each of the three-dimensional flow channel structures with liquid metal includes: The liquid metal is filled into each of the three-dimensional flow channel structures by capillary action or pressure injection.

10. The method according to claim 1, characterized in that The processing of each of the semi-finished metamaterials includes: Each of the semi-finished metamaterials is sealed with a packaging material; the packaging material includes a polymer or a ceramic.

Images