Liquid metal magnetoelectric sensor and integrated additive manufacturing method thereof

Abstract

The application belongs to the technical field of flexible magnetoelectric sensor preparation, and particularly discloses a liquid metal magnetoelectric sensor and an integrated additive manufacturing method thereof, which comprises the following steps: adopting a 3D printing technology, printing a three-dimensional porous base structure according to a pre-constructed three-dimensional model of a magnetic base by using mixed powder, wherein the mixed powder comprises uniformly mixed flexible high polymer powder and strong magnetic powder; magnetizing the three-dimensional porous base structure to obtain a three-dimensional porous magnetic base; performing wetting treatment on the three-dimensional porous magnetic base, and transferring paste-shaped liquid metal to the inner and outer surfaces of the wetted three-dimensional porous magnetic base to obtain an integrated formed liquid metal magnetoelectric sensor. The application has higher efficiency in preparing the flexible magnetoelectric sensor.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of flexible magnetoelectric sensor preparation, and more particularly relates to a liquid metal magnetoelectric sensor and an integrated additive manufacturing method thereof. BACKGROUND

[0002] Flexible sensors refer to sensors made of flexible materials, which have good flexibility, ductility, and flexible and diverse structural forms, and can very conveniently detect complex measured environments. Self-powered flexible sensors have greater application potential due to their obvious advantages of being passive, small in size, low in manufacturing and maintenance cost. Flexible strain sensors mainly use piezoelectric effect, triboelectric effect or electromagnetic induction effect to convert biomechanical energy into visible electrical signals, and thus have broad application prospects in wearable devices, intelligent robots, medical monitoring devices and other fields. At present, self-powered flexible sensors based on piezoelectric effect and triboelectric effect are more common, while self-powered flexible sensors based on electromagnetic induction effect are less common. Although piezoelectric effect or triboelectric effect can rapidly convert mechanical energy into electrical energy, such sensors have considerable internal resistance, resulting in loss of electrical energy and limiting their application.

[0003] At present, there are related patent documents on the preparation of flexible magnetoelectric sensors by mold forming and assembly, for example, the patent document with application number 202210060954.6 discloses an active telescopic magnetoelectric sensor, which is assembled by an elastic member with an embedded conductive coil formed by a mold method and another elastic body with an embedded magnetic body. This assembly manufacturing method is low in efficiency. Related patent documents on the preparation of flexible magnetoelectric devices with complex structures by additive manufacturing and assembly method exist, for example, the patent document 202010158697.0 discloses a flexible piezoelectric sensor based on 4D printing and a preparation method, which combines the magnetic part and the conductive part manufactured by additive manufacturing to realize the controllable change of piezoelectric performance and sensing function of the component under external force. However, this magnetoelectric sensor forming method still has the following disadvantages: (1) the magnetic material part and the conductive part need to be manufactured separately and then assembled, which is low in production efficiency; (2) the preparation process needs to consider the matching of the stiffness and size of the magnetic material part and the conductive part, which is high in preparation difficulty; (3) the deformation direction of the magnetoelectric device that can generate obvious electrical signals is single, and the structural design freedom is low. Therefore, in view of the above problems, there is an urgent need for a new efficient preparation method of flexible magnetoelectric sensors. SUMMARY

[0004] In view of the defects of the prior art, the purpose of the present application is to provide a liquid metal magnetoelectric sensor and an integrated additive manufacturing method thereof, so as to solve the problems of low preparation efficiency and high preparation difficulty of the existing flexible magnetoelectric sensor preparation method.

[0005] To achieve the above object, the application provides a liquid metal magnetoelectric sensor and an integrated additive manufacturing method thereof, comprising the following steps:

[0006] S1, printing a three-dimensional porous base structure according to a pre-constructed three-dimensional model of a magnetic base by using mixed powder through a 3D printing technology, wherein the mixed powder comprises uniformly mixed flexible high polymer powder and strong magnetic powder;

[0007] S2, magnetizing the three-dimensional porous base structure to obtain a three-dimensional porous magnetic base;

[0008] S3, wetting treatment of the three-dimensional porous magnetic base;

[0009] S4, transferring the paste-shaped liquid metal after oxidation treatment to the inner and outer surfaces of the wet three-dimensional porous magnetic base to obtain an integrated liquid metal magnetoelectric sensor.

[0010] Further, in step S1, the mass fraction of the strong magnetic powder in the mixed powder is 20%-50%.

[0011] Further, in step S1, the flexible high polymer material is thermoplastic polyurethane powder, and the strong magnetic powder is at least one metal powder selected from neodymium iron boron powder, ferrite powder, iron-nickel powder and iron-cobalt powder.

[0012] Further, the liquid metal comprises at least a gallium metal component; preferably, the liquid metal further comprises at least one metal component selected from indium and tin.

[0013] Further, the oxidation treatment method of the paste-shaped liquid metal is as follows: the liquid metal is stirred by using a magnetic stirrer for a preset time to obtain paste-shaped liquid metal containing solid oxides.

[0014] Further, in step S1, the method for preparing the mixed powder is as follows: the flexible high polymer powder and the strong magnetic powder are dried to obtain dried powder; and the dried powder is mixed with a rheological additive to obtain the mixed powder.

[0015] Further, in step S2, the method for printing the three-dimensional porous base structure is as follows: a laser selective sintering process is adopted, and the mixed powder is laser sintered to form the three-dimensional porous base structure; or an extrusion melting process is adopted, a wire is prepared by using the mixed powder, and the wire is extrusion melted to form the three-dimensional porous base structure.

[0016] Further, in step S3, the three-dimensional porous base structure is wetted by using a binder; and the binder is preferably polyvinyl alcohol or polymethacrylate solution.

[0017] Further, in step S3, the paste liquid metal is applied multiple times on the surface of the three-dimensional porous magnetic matrix, and the paste liquid metal is immersed into the three-dimensional porous magnetic matrix from top to bottom and from outside to inside under the action of gravity, so that the surface of all the pore structures is uniformly covered with a liquid metal film of a certain thickness.

[0018] A liquid metal magnetoelectric sensor prepared by using the integrated additive manufacturing method according to any one of the preceding embodiments, comprising:

[0019] The three-dimensional porous magnetic matrix is made of a mixed powder of a flexible high polymer material and a strong magnetic powder according to a pre-constructed three-dimensional model of the magnetic matrix, and can be deformed under the action of an external force.

[0020] The conductive path is composed of the paste liquid metal transferred on the inner and outer surfaces of the three-dimensional porous magnetic matrix, and when the three-dimensional porous magnetic matrix is deformed, the conductive path also deforms along with the three-dimensional porous magnetic matrix, so that the magnetic flux passing through the conductive path changes to generate an electric signal.

[0021] Compared with the prior art, the above technical scheme has the following advantages:

[0022] 1. The three-dimensional porous matrix structure is integrally formed by using a composite material obtained by uniformly mixing a flexible high polymer powder material and a strong magnetic powder material through the 3D printing technology, so that the three-dimensional porous matrix structure has good compressive mechanical properties, and the liquid metal is transferred onto the three-dimensional porous matrix structure after magnetization to form a conductive path through the transfer technology, thereby solving the matching problem of the rigidity coefficient of the magnetic material part and the conductive part, and the three-dimensional porous matrix structure is printed according to a pre-constructed three-dimensional porous matrix model, and the three-dimensional porous matrix model can be freely designed into various shapes.

[0023] 2. The three-dimensional porous magnetic matrix is wetted by a binder in advance during the three-dimensional transfer process, which effectively solves the problem of poor wettability and difficult direct adhesion between the paste liquid metal and the 3D printed matrix, the binder not only fills the small gaps on the surface of the 3D printed matrix to increase the effective adhesion area of the liquid metal, but also forms strong hydrogen bonds with the liquid metal to promote the stable adhesion of the liquid metal, so that the prepared liquid metal magnetoelectric sensor has high integration.

[0024] 3. The paste-like liquid metal obtained by the oxidation treatment in the present application not only reduces the surface tension and fluidity of the liquid metal, but also strengthens the strong hydrogen bond between the liquid metal and the binder, so that when the three-dimensional porous magnetic matrix is mechanically deformed, the liquid metal attached to the surface of the binder exhibits the characteristics of autonomous surface coordination. After the paste-like liquid metal is coated on the three-dimensional porous magnetic matrix, the liquid metal layer can automatically reconstruct its surface according to the porous structure after compression / recovery, so that the preparation of reversible compression conductive paths is realized.

[0025] 4. The present application realizes the integrated preparation of the magnetic compressible lattice and the three-dimensional conductive path structure by using the additive manufacturing technology, thereby avoiding the assembly process of multiple components. At the same time, the conformal adhesion of the liquid metal causes the deformation of the three-dimensional porous magnetic matrix in any direction to result in the change of the magnetic flux in the conductive path, so that the liquid metal magnetoelectric sensor has high design freedom, and the three-dimensional porous structure model can be designed into different unit sizes, volume fractions and various three-dimensional lattice structure models with gradient changes in volume fraction. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structure schematic diagram of a liquid metal magnetoelectric sensor prepared by an embodiment of the present application;

[0027] Figure 2 is a principle schematic diagram of the generation of an electric signal by a liquid metal magnetoelectric sensor prepared by an embodiment of the present application;

[0028] Figure 3 is a flow chart of the integrated additive manufacturing method of the liquid metal magnetoelectric sensor in the embodiment of the present application;

[0029] Figure 4 is a schematic diagram of the forming process of the liquid metal magnetoelectric sensor in the embodiment of the present application;

[0030] Figure 5 is a comparison diagram of the three-dimensional porous magnetic matrix before and after the adhesion of the liquid metal in embodiment 1 of the present application;

[0031] Figure 6 is a schematic diagram of the voltage-time curve and the current-time curve of the electric signal collected in the force-electricity conversion performance test of embodiment 2 of the present application under the action of the cyclic external pressure. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0033] As Figure 1As shown, it is a liquid metal magnetoelectric sensor prepared by an integrated additive manufacturing method of liquid metal magnetoelectric sensor, and the structure thereof comprises:

[0034] A three-dimensional porous magnetic matrix which is made of mixed powder of flexible polymer material and strong magnetic powder according to a pre-constructed three-dimensional model of magnetic matrix by using 3D printing technology, and which can be deformed under external force;

[0035] And a conductive path which is composed of paste liquid metal transferred on the inner and outer surfaces of the three-dimensional porous magnetic matrix, as shown in Figure 2 When the three-dimensional porous magnetic matrix is deformed, the conductive path also deforms with the three-dimensional porous magnetic matrix, thereby changing the magnetic flux passing through the conductive path to generate an electric signal.

[0036] As shown in Figure 3 It is a flow chart of the integrated additive manufacturing method of the aforementioned liquid metal magnetoelectric sensor, which comprises material preparation, structure design and integrated forming, combined with Figure 4 As shown, the specific preparation steps of the liquid metal magnetoelectric sensor are as follows:

[0037] S1 uses 3D printing technology to print a three-dimensional porous matrix structure (i.e. the lattice structure in the figure) according to a pre-constructed three-dimensional model of magnetic matrix (TPMS lattice structure in the figure, i.e. triple minimal surface structure) by using mixed powder, and the mixed powder includes uniformly mixed flexible polymer powder and strong magnetic powder;

[0038] S2 magnetizes the three-dimensional porous matrix structure to obtain a three-dimensional porous magnetic matrix (i.e. the magnetic lattice matrix in the figure); specifically, the magnetizing process uses a pulse magnetizing device, and the magnetizing voltage is adjustable within the range of 1800V-2000V;

[0039] S3 wet treatment of the three-dimensional porous magnetic matrix;

[0040] S4 transfers the paste liquid metal after oxidation treatment to the inner and outer surfaces of the wet three-dimensional porous magnetic matrix to obtain an integrated formed liquid metal magnetoelectric sensor.

[0041] In the preferred embodiment, in step S1, the mass fraction of the strong magnetic powder in the mixed powder is 20%-50%, such as 20%, 25%, 30%, 45%, 50%, etc., and the mass fraction of the flexible polymer powder in the mixed powder is 20%-80%, such as 20%, 25%, 30%, 45%, 50%, 60%, 65%, 70%, 75%, 80%, etc.

[0042] In the preferred embodiment, in step S1, the flexible high polymer material is thermoplastic polyurethane powder (TPU), and the strong magnetic powder is at least one metal powder selected from the group consisting of neodymium iron boron powder, ferrite powder, iron-nickel powder and iron-cobalt powder, such as neodymium iron boron powder, such as neodymium iron boron powder and ferrite powder, such as ferrite powder, iron-nickel powder and iron-cobalt powder.

[0043] In the preferred embodiment, the aforementioned liquid metal must contain gallium metal elements; more preferably, it can also contain any one or both of indium and tin metal components; the mass fraction of each of the aforementioned metal elements can be adjusted as needed.

[0044] In the preferred embodiment, the method for oxidizing the paste-like liquid metal is to use a magnetic stirrer to stir the liquid metal for a predetermined time for oxidation treatment, thereby obtaining a paste-like liquid metal containing solid oxides; specifically, the magnetic stirrer stirs at a certain rate to significantly reduce the surface tension and flowability of the liquid metal, and make it contain solid oxides (such as Ga2O3).

[0045] In the preferred embodiment, in step S1, the method for preparing the mixed powder is to dry the flexible high polymer powder and the strong magnetic powder to obtain dried powder; then mix the dried powder with rheological additives to obtain the mixed powder; specifically, 12g of rheological additives is added to 1000g of the mixed powder of the flexible high polymer powder and the strong magnetic powder, that is, the mixing ratio of the mixed powder to the rheological additives is 250:3; more specifically, the rheological additives mainly include one or more of powdery materials such as fumed silica, castor oil derivatives and polyethylene wax.

[0046] In the preferred embodiment, in step S2, the method for printing the three-dimensional porous matrix structure is to use a laser selective sintering process to laser sinter the mixed powder to obtain the three-dimensional porous matrix structure; or to use an extrusion melting process to prepare a wire material from the mixed powder, and then use the wire material to extrusion melt to obtain the three-dimensional porous matrix structure.

[0047] In the preferred embodiment, in step S3, the three-dimensional porous matrix structure is wetted with a binder; the binder is preferably polyvinyl alcohol or polymethacrylate solution; specifically, the three-dimensional porous magnetic matrix is soaked in the binder until the inner and outer surfaces of the three-dimensional porous magnetic matrix are completely wetted, and then the three-dimensional porous magnetic matrix is dried at a specific low temperature for a specific period of time, such as 60 minutes at 50°C, and then the transfer step is performed.

[0048] In the preferred embodiment, in step S3, the paste-like liquid metal is applied multiple times to the surface of the three-dimensional porous magnetic matrix, and the paste-like liquid metal is allowed to immerse into the three-dimensional porous magnetic matrix from top to bottom and from outside to inside under the action of gravity, so that the surface of all the pore structures is uniformly covered with a liquid metal film of a certain thickness, and the three-dimensional porous magnetic matrix structure before and after the application is as shown inFigure 5 Specifically, the thickness of the liquid metal film (i.e. the three-dimensional conductive path) can be regulated by adjusting the stirring time during the oxidation of the liquid metal and the subsequent number of coating times.

[0049] In order to better illustrate the implementation details of the present application, the following examples are given to further illustrate the present application, but it should be clear that the content of the examples is not as a further limitation on the scope of protection of the present application.

[0050] Example 1

[0051] (1) Select strong magnetic neodymium iron boron (NdFeB) powder and thermoplastic polyurethane (TPU) powder and rheological additive polyethylene wax powder to prepare a mixed powder, the mass fraction of neodymium iron boron powder in this embodiment is 40%, after drying the three powders, they are mixed in a planetary ball mill at a speed of 600 revolutions per minute, to obtain a mixed powder with uniform color.

[0052] (2) Construct a TPMS lattice structure model (triple minimal surface structure), the outer contour size of the TPMS lattice structure model is 20mm x 20mm x 15mm, wherein the unit cell size is 8mm, the volume fraction is 15%, and two pins are designed on the outside of the porous structure, with a size of 5mm x 3mm x 1.5mm.

[0053] (3) According to the model constructed in step (2), the mixed powder prepared in step (1) is formed by laser selective sintering process, and the specific processing parameters are as follows: laser scanning speed is 2000mm / s, scanning interval is 0.2mm, laser power is 30W, powder layer thickness is 0.15mm, and working cavity temperature is 93℃, to obtain a three-dimensional porous matrix structure; the three-dimensional porous matrix structure is placed in a pulse magnetizing machine to be magnetized to obtain a three-dimensional porous magnetic matrix, and the magnetizing voltage is set to 1900V.

[0054] (4) Select polymethacrylate (PMA) solution as the binder, immerse the three-dimensional porous magnetic matrix in the PMA solution until all the surfaces of the matrix are wetted by the PMA solution from the inside to the outside, and then dry at 50℃ for 60 minutes.

[0055] (5) Select liquid metal gallium indium tin alloy (Ga: 68.5wt%, In: 21.5wt%, Sn: 10wt%), place it in a magnetic stirrer for stirring and oxidation, until the liquid metal solution becomes paste-like in texture.

[0056] (6) Put the wet three-dimensional porous magnetic matrix obtained in step (4) into a container, apply liquid metal on the upper surface, and let the liquid metal soak into the three-dimensional porous matrix structure under the action of gravity, then rotate the matrix with the uncoated surface facing up and repeat the coating operation until all surfaces inside and outside the matrix are adhered with liquid metal, and then the integration and forming of the magnetoelectric sensor is completed, refer to Figure 5 Comparison of the three-dimensional porous magnetic matrix formed by laser selective sintering (left) and the magnetoelectric sensor formed after adhesion of liquid metal (right).

[0057] Example 2

[0058] (1) Select strong magnetic neodymium iron boron (NdFeB) powder, thermoplastic polyurethane (TPU) powder and rheological additive fumed silica powder to prepare a mixed powder, wherein the mass fraction of neodymium iron boron powder is 50%, pour the three powders into a planetary ball mill at a speed of 600 revolutions per minute to obtain a mixed powder with uniform color.

[0059] (2) Construct a series of TPMS lattice structure models, all with an outer contour size of 20mm x 20mm x 15mm and a unit cell size of 7mm, with volume fractions of 12.5%, 15%, 17.5% and 20% respectively, and both external pins of the TPMS lattice structure model have a size of 5mm x 3mm x 1.5mm.

[0060] (3) According to the model constructed in step (2), the mixed powder prepared in step (1) is formed by laser selective sintering process, with the following parameters: laser scanning speed of 2000mm / s, scanning interval of 0.15mm, laser power of 25W, powder layer thickness of 0.15mm, and working cavity temperature of 96℃, to obtain a three-dimensional porous matrix structure; place the three-dimensional porous matrix structure in a pulse magnetizer to obtain a three-dimensional porous magnetic matrix, set the magnetizing voltage to 1800V.

[0061] (4) Select the binder polymethacrylate (PMA), immerse the three-dimensional porous magnetic matrix in the PMA solution until all surfaces inside and outside are wetted with the solution, then dry at 50℃ for 60 minutes.

[0062] (5) Select liquid metal gallium-indium eutectic alloy (Ga: 75wt%, In: 25wt%), place it in a magnetic stirrer for stirring and oxidation until the liquid metal solution becomes a paste-like texture.

[0063] (6) Put the wet three-dimensional porous magnetic matrix obtained in step (4) into a container, smear the liquid metal on the upper surface, and immerse the liquid metal into the porous structure under the action of gravity, then rotate the matrix to repeat the above smearing operation until all surfaces inside and outside the matrix are adhered with the paste-like liquid metal, and then the integrated formation of the magnetoelectric sensor is completed.

[0064] Example 3

[0065] (1) Select strong magnetic iron-cobalt powder, thermoplastic polyurethane (TPU) powder and rheological additive castor oil derivative, wherein the mass fraction of iron-cobalt powder is 30%, pour the three powders into a planetary ball mill at a speed of 600 revolutions per minute to obtain a mixed powder with uniform color.

[0066] (2) Construct a TPMS lattice structure model with an outer contour size of 10 mm x 10 mm x 15 mm, wherein the unit cell size is 6 mm and the volume fraction is 20%, and the size of the two pins on the outside of the TPMS lattice structure model is 5 mm x 3 mm x 1.5 mm.

[0067] (3) According to the model constructed in step (2), the mixed powder prepared in step (1) is formed by laser selective sintering process, and the processing parameters are as follows: laser scanning speed is 2000 mm / s, scanning interval is 0.2 mm, laser power is 25 W, powder layer thickness is 0.15 mm, and the temperature of the working cavity is 90°C. A three-dimensional porous matrix structure is obtained. The three-dimensional porous matrix structure is placed in a pulse magnetizer to obtain a three-dimensional porous magnetic matrix, and the magnetizing voltage is set to 2000V.

[0068] (4) Select the binder polyvinyl alcohol (PVA), and immerse the three-dimensional porous magnetic matrix in the PVA solution until all surfaces of the three-dimensional porous matrix structure are wetted with the PVA solution. Then, dry at 50°C for 30 minutes.

[0069] (5) Select liquid metal gallium-tin alloy (Ga: 65wt%, Sn: 35wt%), and place it in a magnetic stirrer for stirring and oxidation until the liquid metal solution has a paste-like texture.

[0070] (6) Put the wet three-dimensional porous magnetic matrix obtained in step (4) into a container, smear the paste-like liquid metal on the upper surface, and immerse the paste-like liquid metal into the porous structure under the action of gravity, then rotate the three-dimensional porous matrix structure to repeat the above operation until all surfaces inside and outside the matrix are adhered with the liquid metal, and then the integrated formation of the magnetoelectric sensor is completed.

[0071] Example 4

[0072] (1) Select strong magnetic NdFeB (NdFeB) powder and thermoplastic polyurethane (TPU) powder, the mass fraction of NdFeB powder is 20%, and a screw extruder is used to prepare a wire.

[0073] (2) Construct a TPMS lattice structure matrix with an outer contour size of 10mm x 10mm x 15mm, wherein the unit cell size is 7mm and the volume fraction is 20%, and the outer two pins of the TPMS lattice structure matrix have a size of 2mm x 2mm x 0.5mm.

[0074] (3) The wire prepared in step (1) is obtained by using an extrusion melting process to obtain a three-dimensional porous matrix structure, and the three-dimensional porous matrix structure is magnetized in a pulse type magnetizer to obtain a three-dimensional porous magnetic matrix, and the magnetizing voltage is set to 2000V.

[0075] (4) Select the binder polyvinyl alcohol (PVA), immerse the three-dimensional porous magnetic matrix in the PVA solution until all the surfaces of the three-dimensional porous magnetic matrix are wetted by the PVA solution, and then dry at 50°C for 30 minutes.

[0076] (5) Select liquid metal gallium-indium-tin alloy (Ga: 68.5wt%, In: 21.5wt%, Sn: 10wt%), and stir and oxidize it in a magnetic stirrer until the liquid metal solution has a paste-like texture.

[0077] (6) Put the three-dimensional porous magnetic matrix obtained in step (4) into a container, smear the liquid metal on the upper surface, and immerse the paste-like liquid metal into the three-dimensional porous magnetic matrix under the action of gravity, then rotate the matrix with the uncoated surface facing up, and repeat the above smearing step until the inner and outer surfaces of the three-dimensional porous magnetic matrix are adhered with liquid metal, i.e. the magnetoelectric sensor is integrated and formed.

[0078] The four liquid metal magnetoelectric sensors 7-12.5, 7-15, 7-17.5 and 7-20 prepared in Example 2 are tested for performance and function verification:

[0079] The four liquid metal sensors prepared in Example 2 are subjected to cyclic external pressure to perform periodic compression / recovery motion.

[0080] Specifically, the compression amount is constant at 5mm (device height 15mm), and the compression rate is 50mm / s. During the cycle, the voltage and current generated by each liquid metal sensor vary with time as follows: Figure 6It can be seen from the figures that all the samples can generate certain induced voltage and induced current, the sample 7-12.5 generates the largest induced voltage and induced current, the corresponding voltage peak value is 5.36 μV, and the corresponding current peak value is 588.53 pA. It can be seen that in the compression process of the liquid metal sensor, the magnetic flux in the conductive path changes to generate an induced voltage, and a corresponding current signal can be obtained by connecting a loop. In summary, the liquid metal magnetoelectric device prepared according to the technical scheme provided in the application has excellent force-electricity conversion performance and sensing function.

[0081] The above merely describes preferred embodiments of the application and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. An integrated additive manufacturing method for a liquid metal magnetoelectric sensor, characterized in that, The method comprises the following steps: S1: using 3D printing technology, printing a three-dimensional porous matrix structure according to a pre-constructed three-dimensional model of a magnetic matrix by using mixed powder, wherein the mixed powder comprises uniformly mixed flexible high polymer powder and strong magnetic powder; S2: magnetizing the three-dimensional porous matrix structure to obtain a three-dimensional porous magnetic matrix; S3: using polyvinyl alcohol or polymethacrylate solution as a binder to wet treat the three-dimensional porous magnetic matrix; S4: transferring the paste-like liquid metal after oxidation treatment to the inner and outer surfaces of the wet three-dimensional porous magnetic matrix to obtain an integrally formed liquid metal magnetoelectric sensor.

2. A method of integrated additive manufacturing of a liquid metal magnetoelectric sensor as claimed in claim 1, wherein, In step S1, the mass fraction of the strong magnetic powder in the mixed powder is 20%-50%.

3. A method of integrated additive manufacturing of a liquid metal magnetoelectric sensor as claimed in claim 1, wherein, In step S1, the flexible high polymer powder is thermoplastic polyurethane powder, and the strong magnetic powder is at least one metal powder selected from the group consisting of neodymium iron boron powder, ferrite powder, iron-nickel powder, and iron-cobalt powder.

4. A method of integrated additive manufacturing of a liquid metal magnetoelectric sensor as claimed in claim 1, wherein, The liquid metal comprises at least a gallium metal component, and further comprises at least one metal component selected from the group consisting of indium and tin.

5. A method of integrated additive manufacturing of a liquid metal magnetoelectric sensor as claimed in claim 1, wherein, The oxidation treatment method of the paste-like liquid metal comprises: using a magnetic stirrer to stir the liquid metal for a preset time to perform oxidation treatment, thereby obtaining paste-like liquid metal containing solid oxides.

6. A method of integrated additive manufacturing of a liquid metal magnetoelectric sensor as claimed in claim 1, wherein, In step S1, the method for preparing the mixed powder comprises: drying the flexible high polymer powder and the strong magnetic powder to obtain dried powder; and mixing the dried powder with a rheological additive to obtain the mixed powder.

7. A method of integrated additive manufacturing of a liquid metal magnetoelectric sensor as claimed in claim 1, wherein, In step S2, the method for printing the three-dimensional porous matrix structure comprises: using a laser selective sintering process to laser sinter the mixed powder to form the three-dimensional porous matrix structure; or using an extrusion melting process to prepare a wire from the mixed powder, and using the wire to perform extrusion melting to form the three-dimensional porous matrix structure.

8. A method of integrated additive manufacturing of a liquid metal magnetoelectric sensor as claimed in claim 1, wherein, In step S3, the paste-like liquid metal is applied multiple times on the surface of the three-dimensional porous magnetic matrix, and the paste-like liquid metal is immersed into the three-dimensional porous magnetic matrix from top to bottom and from outside to inside under the action of gravity, so that all the pore structure surfaces are uniformly covered with a liquid metal film with a certain thickness.

9. A liquid metal magnetoelectric sensor prepared by the integrated additive manufacturing method according to any one of claims 1-8. The method comprises: a three-dimensional porous magnetic matrix, which is prepared by using 3D printing technology and mixed powder formed by mixing flexible high polymer powder and strong magnetic powder according to a pre-constructed three-dimensional model of a magnetic matrix, and which can deform under the action of an external force; and a conductive path composed of paste-like liquid metal transferred to the inner and outer surfaces of the three-dimensional porous magnetic matrix, wherein when the three-dimensional porous magnetic matrix deforms, the conductive path also deforms along with the three-dimensional porous magnetic matrix, thereby changing the magnetic flux passing through the conductive path to generate an electric signal.

Images