Preparation method of magnetoelastomer with high magnetic phase content and magnetoelastomer

Abstract

According to the preparation method of the high-magnetic-phase-content magneto-elastomer and the magneto-elastomer, in the process of preparing the magneto-elastomer through photocuring 3D printing, micron-sized light guide fibers are added, a light guide path is constructed in a magnetic powder-resin system, and the magnetic phase content gt is obtained; 50 wt.% of a magnetoelastomer; the technical effect of improving the curing thickness and interlayer bonding quality of the magnetoelastomer is achieved.

Description

Technical Field

[0001] This invention relates to the technical field of composite conductive materials, and more specifically, to a method for preparing a magnetoelastic with high magnetic phase content and the magnetoelastic itself. Background Technology

[0002] Flexible electronic devices, due to their excellent folding, bending, compression, and stretching properties, have broad application prospects in energy conversion, wearable devices, healthcare, and information display. As one type, flexible tactile sensors enable interaction between machines and their external environment and have been widely used. Currently, common flexible tactile sensors mainly include capacitive, resistive, and piezoelectric types. However, sensors based on these principles generally suffer from poor output linearity and large hysteresis, limiting their application range. Magnetic sensors, due to their simple structure, high linearity, and long lifespan, have received increasing attention in recent years. Traditional magnetic flexible sensors are mostly fabricated by combining a rigid permanent magnet block with an elastic substrate, but this method does not meet the requirements of flexible electronic devices for portability, flexibility, and stretchability. Therefore, magnetic elastomers are currently used instead of the combination of permanent magnets and magnetic films. However, the magnetic material distribution in magnetic elastomers is relatively dispersed, and the magnetic phase content is usually only about 30 wt.%, resulting in a weak overall magnetic field strength, which affects the performance of flexible tactile sensors.

[0003] Furthermore, existing methods for fabricating flexible tactile sensors primarily rely on mold forming, resulting in poor consistency and limiting their application in large-scale production. While 3D printing technology can mitigate these issues to some extent, mainstream 3D printing processes (such as DIW and FDM) generally suffer from simple structures and low production efficiency. In contrast, photopolymerization process (DLP) 3D printing offers advantages such as high printing precision, the ability to form complex microstructures, and high production efficiency, making it suitable for fabricating magnetic elastomers in magnetic sensors. However, DLP printing of magnetic elastomers has several drawbacks. The addition of light-absorbing magnetic powder (such as NdFeB) to the flexible photosensitive resin significantly reduces its light transmittance. Ultraviolet light irradiation reduces the resin's cross-linking degree, affecting the interlayer bonding quality of the magnetic elastomer and leading to printing failures due to the inability of the printed layer to effectively bond with the upper layer.

[0004] Therefore, there are still technical problems to be solved in terms of increasing the magnetic phase content of magnetoelastic materials and the DLP printing suitability of high-content magnetic phase materials in current magnetic flexible tactile sensors. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide a method for preparing a magnetoelastic with high magnetic phase content and a magnetoelastic, so as to solve at least one problem existing in the prior art.

[0006] In a first aspect, the present invention provides a method for preparing a magnetoelastic material with high magnetic phase content, comprising breaking down light-guiding raw materials to obtain light-guiding fibers with a length of less than 100 μm; The magnetic material powder, resin and optical fiber are stirred in a vacuum homogenizer for 7-15 minutes according to a preset mass ratio to obtain a well-mixed printing paste. The printing paste was photopolymerized and 3D printed to obtain a magnetoelastic body; wherein the printing parameters were 22-28 mw / cm². 2 The exposure time is 18-22 seconds.

[0007] In addition, an optional technical solution is that the light guide fiber is one or more of SiO2 fiber, glass fiber, PMMA fiber, polycarbonate fiber, polyethylene terephthalate fiber, cellulose nanofiber, polystyrene fiber and TPU fiber.

[0008] Alternatively, the magnetic material may be one of NdFeB, ferrite, SmCo, MnBi, Fe-Co, CIP, Fe-Ni, and samarium iron nitrogen.

[0009] Alternatively, the resin may be one of Agilus30, soft rubber, esun elastic resin, e600 resin, or polyurethane-acrylate elastic resin.

[0010] In addition, an optional technical solution is that when the light guiding material is silicon dioxide material with a diameter of 5μm, the mass ratio of the light guiding fiber is 3wt.%.

[0011] In addition, an optional technical solution is characterized in that the method of crushing the light-guiding raw material is to place the light-guiding raw material in a ball mill jar and perform wet ball milling for 30-40 minutes at a speed of 200-400 rpm.

[0012] Alternatively, an optional technical solution is to stir the magnetic material powder, resin, and optical fiber in a vacuum homogenizer at a stirring speed of 1500rpm-2500rpm.

[0013] In a second aspect, the present invention provides a magnetic elastomer, which is prepared by the magnetic elastomer preparation method with high magnetic phase content as described above; the magnetic phase content of the magnetic elastomer is >50 wt.%.

[0014] Thirdly, the present invention provides a magnetically sensitive sensor, comprising a magnetically elastic material prepared using the high magnetic phase content magnetically elastic material preparation method described above.

[0015] Fourthly, the present invention provides an electronic skin comprising a magnetoelastic obtained by the method for preparing a magnetoelastic with high magnetic phase content as described above.

[0016] This invention discloses a method for preparing a magnetoelastic with high magnetic phase content and the magnetoelastic itself. In the process of preparing a magnetoelastic by photopolymerization 3D printing, by adding micron-sized light-guiding fibers, a light-guiding path is constructed in the magnetic powder-resin system, thereby obtaining a magnetoelastic with a magnetic phase content >50wt.%; achieving the technical effect of improving the curing thickness and interlayer bonding quality of the magnetoelastic.

[0017] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0018] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings. In the drawings: Figure 1 This is a test graph showing the light transmittance of the light guide material according to an embodiment of the present invention; Figure 2 This is a diagram showing the effect of ball milling time on the cured thickness of silica fibers according to an embodiment of the present invention. Figure 3 This diagram illustrates the effect of the diameter of the silica material on the cured thickness according to an embodiment of the present invention. Figure 4 This is a graph showing the effect of the amount of silica fiber added on viscosity according to an embodiment of the present invention; Figure 5 This is a graph showing the effect of the amount of silica fiber added on the magnetic powder settling velocity according to an embodiment of the present invention. Figure 6 This is a comparison chart showing the effect of the amount of silica fiber added on the cured thickness according to an embodiment of the present invention. Figure 7 This is a graph showing the effect of the amount of silica fiber added on the cured thickness under fixed printing parameters according to an embodiment of the present invention. Figure 8 A photograph of a magnetoelastic obtained by curing 3D printing according to an embodiment of the present invention; Figure 9This is a test diagram of the tensile properties of a magnetoelastic body according to an embodiment of the present invention; Figure 10 This is a test diagram of the compressibility of a magnetoelastic body according to an embodiment of the present invention; Figure 11 This is a comparison diagram of the curing thickness of a light guide material with silica particles as a comparative example according to an embodiment of the present invention. In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation methods and typical parameters of the present invention, and are not intended to limit the parameter ranges described in the present invention. Reasonable variations derived therefrom are still within the protection scope of the claims of the present invention. It should be noted that the endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of various ranges, the endpoint values ​​of various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. Unless otherwise defined, all terms, symbols, and other scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In some cases, terms with a conventional understanding are defined herein for clarification or ease of reference; such definitions should not be construed as indicating a significant difference from the conventional understanding in the art. The technical methods described or referenced herein are generally well understood by those skilled in the art and have been adopted by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents, and instruments should be performed in accordance with the manufacturer's instructions and parameters.

[0020] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0021] To address the issue of insufficient curing of high-magnetic-phase-content magnetoelastics during digital light-curing (DLP) 3D printing due to their strong light absorption, attempts have been made to increase the curing thickness by adding light-guiding particles (such as SiO2 particles). However, significant limitations exist: firstly, a relatively high addition amount is required to effectively increase the curing thickness; secondly, as the content of light-guiding particles increases, the viscosity of the printing resin rises significantly, leading to a slower resin reflow rate during printing, and even situations where the resin cannot fully cover the release film after reflow, severely affecting printing continuity and molding quality. Therefore, the upper limit of printable addition of light-guiding particles is typically only 3 wt.%, under which the content of the magnetic phase (such as NdFeB) can only be increased from 30 wt.% to 40 wt.%, a limited improvement. Furthermore, attempts have been made to enhance the curing depth by extending the exposure time or increasing the exposure power, but these methods easily cause over-curing at the resin-release film interface, resulting in a significant increase in release force, which in turn leads to release film deformation, tearing, decreased sample printing accuracy, and increased internal stress, making it difficult to meet the requirements of high-precision and high-reliability printing. Therefore, existing technologies still face significant process bottlenecks and performance limitations in achieving photopolymerization 3D printing of magnetoelastics with high magnetic phase content.

[0022] Compared to existing light-guiding particles, the magnetic elastomer of this invention produces a higher curing thickness under single-layer exposure for the same mass fraction of light-guiding fiber (SiO2 fiber), while having less impact on viscosity, and can increase the magnetic phase content from 30 wt.% to 50 wt.%. Simultaneously, it prevents magnetic powder from settling within 3 hours. Furthermore, the method of adding light-guiding fibers in this invention can also improve the mechanical properties of printed materials (such as tensile strength).

[0023] Preparation Example 1 S1. Place the light-guiding raw material in a ball mill jar and wet-mill at 300 rpm for 30 minutes to obtain light-guiding fibers with a length of less than 100 μm. The light-guiding raw material is silica raw material (pure quartz fiber cotton) with a diameter of 5 μm. A planetary ball mill is used for milling.

[0024] It should be noted that in the specific implementation process, the crushing process is not limited to wet ball milling. Dry ball milling or other methods to crush long light guide fibers into short fibers can also be used. If there are ready-made light guide short fibers with a length of less than 100μm, the ready-made light guide short fibers can also be used.

[0025] S2. The magnetic material powder, resin, and optical fiber are mixed in a preset mass ratio of 50:47:3 in a vacuum homogenizer at a stirring speed of 2000 rpm for 10 minutes to obtain a homogenized printing paste 1. The magnetic material powder is 2000-mesh NdFeB powder; the resin is Agilus 30 resin.

[0026] S3. The printing paste is photocured and 3D printed to obtain a magnetoelastic body; wherein the printing parameters are 25mw / cm. 2 The exposure time was 20 seconds, and the printing layer thickness was set to 0.025 mm. Magnetoelastic material 1 was obtained.

[0027] It should be noted that printing a magnetic elastomer requires a large amount of printing paste to be placed in a cartridge, and the process involves exposure, raising the forming stage by 25 micrometers (the set layer thickness), exposure, raising the forming stage again, and so on, repeating these two processes to finally obtain the magnetic elastomer.

[0028] Preparation Example 2 S1. Place the light-guiding raw material in a ball mill jar and wet-mill at 200 rpm for 40 minutes to obtain light-guiding fibers with a length of less than 100 μm. The light-guiding raw material is PMMA raw material with a diameter of 5 μm.

[0029] S2. The magnetic material powder, resin, and optical fiber are mixed in a preset mass ratio of 500:465:35 in a vacuum homogenizer at a stirring speed of 2500 rpm for 7 minutes to obtain a homogenized printing paste 2. The magnetic material powder is 2000-mesh Fe3O4 (magnetite) nanoparticles; the resin is a soft adhesive.

[0030] S3. The printing paste is photopolymerized and 3D printed to obtain a magnetoelastic body; wherein the printing parameters are 22mw / cm². 2 The exposure time was 22 seconds, and the printing layer thickness was set to 0.025 mm. Magnetoelastic material 2 was obtained.

[0031] Preparation Example 3 S1. Place the light-guiding raw material in a ball mill jar and wet-mill at 400 rpm for 35 minutes to obtain light-guiding fibers with a length of less than 100 μm. The light-guiding raw material is TPU raw material with a diameter of 5 μm.

[0032] S2. The magnetic material powder, resin, and optical fiber are mixed in a preset mass ratio of 500:465:35 in a vacuum homogenizer at a stirring speed of 2500 rpm for 7 minutes to obtain a well-mixed printing paste 3. The magnetic material powder is 2000-mesh SmCo powder; the resin is polyurethane-acrylate elastic resin.

[0033] S3. The printing paste is photopolymerized and 3D printed to obtain a magnetoelastic body; wherein the printing parameters are 28 mw / cm². 2The exposure time was 18 seconds, and the printing layer thickness was set to 0.025 mm. Magnetoelastic material 3 was obtained. The photopolymer 3D printer was a 10-dimensional photopolymer printer.

[0034] The transmittance of silica raw materials, PMMA raw materials, and glass was measured using a spectrometer. The test results are as follows: Figure 1 As shown.

[0035] Through observation Figure 1 It is evident that both silica and PMMA raw materials have a light transmittance of over 95% for ultraviolet light; among them, silica raw materials have the best light transmittance.

[0036] Preparation Example 4 The formulation and experimental steps were the same as those in Preparation Example 1, except for the wet ball milling time; the wet ball milling time was 40 min, and no photocuring printing step was performed after obtaining printing paste 4.

[0037] Comparative Example 1 The formulation and experimental procedures were the same as in Preparation Example 4, except for the wet ball milling time, which was 50 min, yielding printing paste 5. The formulation and experimental procedures were the same as in Preparation Example 4, except for the wet ball milling time, which was 60 min, yielding printing paste 6. The formulation and experimental procedures were the same as in Preparation Example 4, except for the wet ball milling time, which was 70 min, yielding printing paste 7.

[0038] The curing thickness of printing paste 1 obtained in Preparation Example 1, printing paste 4 obtained in Preparation Example 4, printing paste 5, printing paste 6, and printing paste 7 obtained in Comparative Example 1 were compared according to the following test procedures. The test results are shown in [the table below]. Figure 2 .

[0039] Curing thickness testing procedure: First, use a micrometer thickness gauge with an accuracy of 0.001mm to measure and record the thickness of the glass slide. Then, use a dropper to apply the stirred printing paste (e.g., 0% added paste) onto the glass slide. Simultaneously, without inserting the ink cartridge into the photopolymer 3D printer, place the glass slide above the printer's exposure light source (where the ink cartridge would normally be). Start one exposure to print the curing thickness test pattern provided by the photopolymer printer. Place three curing thickness test patterns evenly on each glass slide. Then, use isopropyl alcohol to wash away excess printing paste, leaving only the cured portion. Use the thickness gauge to measure the combined thickness of the cured pattern and the glass slide. Subtract the thickness of the glass slide itself to obtain the curing thickness for a single exposure. Three curing thicknesses can be obtained from one glass slide; averaging these values ​​gives the curing thickness for a single exposure.

[0040] Figure 2This is a graph showing the effect of ball milling time on the cured thickness of silica fibers according to an embodiment of the present invention. By observing... Figure 2 It can be seen that when the ball milling time is less than 30 minutes, the fiber is not ground up; when the ball milling time is 30-40 minutes, the expected cured thickness can be achieved; among them, the optimal ball milling time is 30 minutes.

[0041] Comparative Example 2 The formulation and experimental steps are the same as in Example 1, except that the diameter of the light-guiding material is different. In Example 1, the light-guiding material is pure quartz fiber cotton with a diameter of 3 μm, resulting in printing paste 8. The formulation and experimental steps are the same as in Example 1, except that the diameter of the light-guiding material is different. In Example 2, the light-guiding material is pure quartz fiber cotton with a diameter of 8 μm, resulting in printing paste 9.

[0042] The curing thickness of printing paste 1 obtained in Preparation Example 1, printing paste 8 obtained in Comparative Example 2, and printing paste 9 were compared. The test results are shown in [Figure Number]. Figure 3 . Figure 3 This diagram illustrates the effect of the diameter of the silica material on the cured thickness according to an embodiment of the present invention. By observing... Figure 3 It can be seen that the printing paste prepared from pure quartz fiber cotton with a diameter of 5 μm in Preparation Example 1 has the best curing thickness.

[0043] Comparative Example 3 S1. Magnetic material powder and resin are mixed at a preset mass ratio of 1:1 in a vacuum homogenizer at a stirring speed of 2000 rpm for 10 minutes to obtain a homogenized printing paste. The magnetic material powder is 2000-mesh NdFeB powder; the resin is Agilus 30 resin. That is, the mass ratio of optical fiber is 0 wt.%, resulting in printing paste 10 of Comparative Example 3.

[0044] Comparative Example 4 S1. Place the light-guiding raw material in a ball mill jar and wet-mill at 300 rpm for 30 minutes to obtain light-guiding fibers with a length of less than 100 μm. The light-guiding raw material is silica raw material (pure quartz fiber cotton) with a diameter of 5 μm. A planetary ball mill is used for milling.

[0045] S2. The magnetic material powder, resin, and optical fiber are mixed in a preset mass ratio of 50:49:1 in a vacuum homogenizer at a stirring speed of 2000 rpm for 10 minutes to obtain a homogenized printing paste 11. The magnetic material powder is 2000-mesh NdFeB powder; the resin is Agilus 30 resin. That is, the mass ratio of the optical fiber is 1 wt.%, resulting in the printing paste 11 of Comparative Example 4.

[0046] Comparative Example 5 S1. Place the light-guiding raw material in a ball mill jar and wet-mill at 300 rpm for 30 minutes to obtain light-guiding fibers with a length of less than 100 μm. The light-guiding raw material is silica raw material (pure quartz fiber cotton) with a diameter of 5 μm. A planetary ball mill is used for milling.

[0047] S2. The magnetic material powder, resin, and optical fiber are mixed in a preset mass ratio of 50:48:2 in a vacuum homogenizer at a stirring speed of 2000 rpm for 10 min to obtain a homogenized printing paste 12. The magnetic material powder is 2000-mesh NdFeB powder; the resin is Agilus 30 resin. That is, the mass ratio of the optical fiber is 2 wt.%, resulting in the printing paste 12 of Comparative Example 5.

[0048] Comparative Example 6 S1. Place the light-guiding raw material in a ball mill jar and wet-mill at 300 rpm for 30 minutes to obtain light-guiding fibers with a length of less than 100 μm. The light-guiding raw material is silica raw material (pure quartz fiber cotton) with a diameter of 5 μm. A planetary ball mill is used for milling.

[0049] S2. The magnetic material powder, resin, and optical fiber are mixed in a preset mass ratio of 50:46:4 in a vacuum homogenizer at a stirring speed of 2000 rpm for 10 minutes to obtain a homogenized printing paste 13. The magnetic material powder is 2000-mesh NdFeB powder; the resin is Agilus 30 resin. That is, the mass ratio of the optical fiber is 4 wt.%, resulting in the printing paste 13 of Comparative Example 6.

[0050] The viscosities of printing paste 1 obtained in Preparation Example 1, printing paste 10 obtained in Comparative Example 3, printing paste 11 obtained in Comparative Example 4, printing paste 12 obtained in Comparative Example 5, and printing paste 13 obtained in Comparative Example 6 were compared. The test results are as follows: Figure 4 As shown. Figure 4 This is a graph showing the effect of the amount of silica fiber added on viscosity according to an embodiment of the present invention. By observing... Figure 4 It can be seen that the printing paste 10 of Comparative Example 3, the printing paste 11 of Comparative Example 4, and the printing paste 12 of Comparative Example 5 have relatively low viscosity, while the printing paste 13 of Comparative Example 6 has too high viscosity, resulting in difficulty in reflowing the printing paste prepared by magnetic powder-resin. The printing paste 1 obtained in Preparation Example 1 has a moderate viscosity.

[0051] The sedimentation properties of printing paste 1 obtained in Preparation Example 1, printing paste 10 obtained in Comparative Example 3, printing paste 11 obtained in Comparative Example 4, printing paste 12 obtained in Comparative Example 5, and printing paste 13 obtained in Comparative Example 6 were compared. The test results are as follows: Figure 5 As shown. Figure 5 This is a graph showing the effect of the amount of silica fiber added on the settling velocity of magnetic powder according to an embodiment of the present invention. By observing... Figure 5 As can be seen, adding light guide fiber (SiO2) not only increases the curing thickness by improving the light transmittance of the printing paste, but also adjusts the rheological properties of the paste, appropriately increases the viscosity of the paste, thereby improving the stability of the paste and slowing down the settling speed of the magnetic powder; the magnetic powder settling time is increased from 0.5 hours to 3 hours.

[0052] The curing thickness of printing paste 1 obtained in Preparation Example 1, printing paste 10 obtained in Comparative Example 3, printing paste 11 obtained in Comparative Example 4, printing paste 12 obtained in Comparative Example 5, and printing paste 13 obtained in Comparative Example 6 were compared. The test results are as follows: Figure 6 As shown. Figure 6 This is a comparison chart showing the effect of the amount of silica fiber added on the cured thickness according to an embodiment of the present invention.

[0053] Specifically, the curing thickness process can be carried out with a fixed printing power of 25mw / cm. 2 The prepared printing paste (e.g., 0% added paste) is dropped onto a glass slide. The slide is placed above the printer's exposure light source, and the exposure time is set to 2 seconds. After exposure, the slide is removed, the curing thickness is measured, and the result is recorded. Figure 6 Find a point on a curve, then prepare another glass slide, drop the same printing paste onto it, and follow the same exposure power and operating steps, only changing the exposure time to 6 seconds. Then test the cured thickness to obtain the second point on the curve... Repeat this step, changing only the exposure time each time, for a total of 8 times, to obtain the desired result. Figure 6 Curing thickness curve with 0% addition.

[0054] The curing thickness of printing paste 1 obtained in Preparation Example 1, printing paste 10 obtained in Comparative Example 3, printing paste 11 obtained in Comparative Example 4, printing paste 12 obtained in Comparative Example 5, and printing paste 13 obtained in Comparative Example 6 were compared. The test results are as follows: Figure 7 As shown. Figure 7 This is a graph showing the effect of the amount of silica fiber added on the cured thickness under fixed printing parameters according to an embodiment of the present invention. By observing... Figure 6 and Figure 7 It is evident that, through a comprehensive comparison of the effects of the addition amount on the cured thickness and viscosity, a silica optical fiber addition amount of 3 wt.% was selected. Specifically, although Figure 6The results show that a 4 wt.% curing thickness is higher than that of 3 wt.%, but the viscosity is too high at 4 wt.%. Experimental tests revealed that the printing paste prepared from magnetic powder and resin was difficult to reflow. Therefore, a 3 wt.% addition of silica optical fiber resulted in the best curing thickness. Compared to the unadded case, adding optical fiber (SiO2) increased the curing thickness by 37% in a single exposure under the same parameters, enabling successful printing with a magnetic phase content of 50 wt.%.

[0055] The magnetoelastic body 1 obtained in Preparation Example 1 was photographed to obtain... Figure 8 . Figure 8 This is a physical image of a magnetoelastic body obtained by curing 3D printing according to an embodiment of the present invention. (By observing...) Figure 8 As can be seen from the perspective of cured thickness after a single exposure, the added silica fiber, which does not react with either the magnetic powder or the resin, significantly increases the cured thickness after a single exposure. This indicates that the addition of light-guiding fiber increases the light transmittance of the printing paste, proving that the light-guiding fiber constructs a light-guiding path in the magnetic powder-resin system. The tensile properties of the sample of magnetoelastic 1 obtained in Preparation Example 1 (GB / T528-2009 standard tensile test part) were tested using an Instron universal testing machine at a speed of 5 mm / min. The test results are shown below. Figure 9 . Figure 9 This is a test diagram of the tensile properties of a magnetoelastic body according to an embodiment of the present invention. By observation... Figure 9 As can be seen, the elastic modulus of the printed standard tensile specimen is 0.98 MPa, and the elongation at break is 51%. The compressive properties of the sample (a cylinder 10 mm high and 13 mm in diameter) of the magnetoelastic body 1 obtained in Example 1 were tested using an Instron universal testing machine at a compression rate of 1 mm / min; the test results are shown in [Figure number missing]. Figure 10 . Figure 10 This is a test diagram of the compressibility properties of a magnetoelastic body according to an embodiment of the present invention. By observation... Figure 10 As can be seen, the recovery rate was 94% and the hysteresis was 18.7% when compressed by 30%. The elastomers obtained in Preparation Examples 2-4 were all subjected to the above tests, and the test results all met the design expectations. The magnetic elastomer preparation method of the present invention completely solves the problems of excessive curing at the resin-release film interface, which leads to a significant increase in release force, causing release film deformation or even tearing, low sample printing accuracy, and high internal stress.

[0056] Comparative Example 7 S1. Magnetic material powder, resin, and silica particles are mixed in a preset mass ratio of 50:49:1 in a vacuum homogenizer at a stirring speed of 2000 rpm for 10 minutes to obtain a homogenized printing paste. The silica particles have a particle size of 5 micrometers, the magnetic material powder is 2000-mesh NdFeB powder, and the resin is Agilus 30 resin. That is, the mass ratio of silica particles is 1 wt.%, resulting in printing paste 14 of Comparative Example 7.

[0057] Comparative Example 8 The formulation and experimental steps were the same as those of Comparative Example 7. Magnetic material powder, resin and silica particles were mixed in a preset mass ratio of 50:48:2, that is, the mass ratio of silica particles was 2wt.%, to obtain printing paste 15.

[0058] Comparative Example 9 The formulation and experimental steps were the same as those of Comparative Example 7. Magnetic material powder, resin and silica particles were mixed in a preset mass ratio of 50:47:3, that is, the mass ratio of silica particles was 3 wt.%, to obtain printing paste 16.

[0059] The curing thickness of printing paste 1 obtained in Preparation Example 1, printing paste 10 obtained in Comparative Example 3, printing paste 14 obtained in Comparative Example 7, printing paste 15 obtained in Comparative Example 8, and printing paste 16 obtained in Comparative Example 9 were compared. The test results are as follows: Figure 11 As shown. Figure 11 This is a comparison diagram of the curing thickness of a light guide material using silica particles as a light guide material, according to an embodiment of the present invention. By observation... Figure 11 It is evident that the cured thickness of the printing paste obtained by using silica particles as a light guide material did not meet expectations. This indicates that adding silica fibers obtained through wet ball milling as light guide fibers enhances the resin's light transmittance, allowing ultraviolet light to penetrate deeper during printing and thus improving the resin's cross-linking degree.

[0060] Example 1 Using the magnetoelastic material 1 obtained in Example 1, a magnetic sensor is fabricated. The improved magnetoelastic material exhibits greater remanence, resulting in a larger magnetic field change during deformation, thus enhancing its sensitivity. Furthermore, achieving the same magnetic field change requires a smaller volume, facilitating miniaturization and thinner designs. Additionally, the increased remanence allows the Hall effect sensor in the magnetic tactile sensor to detect deformation over a larger area, promoting a wider detection range.

[0061] Specifically, the magnetoelastic material 1 obtained in Example 1 is combined with a magnetic sensor (Hall sensor, giant magnetoresistive sensor GMR, tunneling magnetoresistive sensor TMR, etc.) to form a magnetically sensitive tactile (pressure) sensor. When the magnetoelastic material deforms, it generates a change in magnetic field, which is detected by the magnetic sensor and converted into force data. The fabricated magnetically sensitive tactile (pressure) sensor can be applied to various scenarios requiring pressure detection, such as on the fingers of humanoid robots and on medical prostheses.

[0062] The magnetoelastic material obtained using this invention can also be used in magnetically sensitive electronic skin and flexible permanent magnets, with improved technical effects.

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0064] Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within the invention. No appended diagram markings in the claims should be construed as limiting the scope of the claims.

[0065] Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or systems stated in a system claim may also be implemented by a single unit or system through software or hardware.

[0066] However, those skilled in the art should understand that various modifications can be made to the method for preparing high magnetic phase content magnetoelastics and the magnetoelastics proposed in this invention without departing from the scope of this invention. Therefore, the scope of protection of this invention should be determined by the content of the appended claims.

Claims

1. A method of preparing a magnetoelastic body having a high content of magnetic phase, characterized in that, The method comprises the following steps: The light guide raw material is broken to obtain light guide fibers with a length of less than 100 microns; The magnetic material powder, the resin and the light guide fibers are stirred in a vacuum homogenizer for 7-15 minutes at a predetermined mass ratio to obtain a mixed printing paste; The printing paste is subjected to photocuring 3D printing to obtain a magnetoelastic body; wherein the printing parameters are 22-28 mw / cm 2 and the exposure time is 18-22 s.

2. The method for preparing a magnetoelastic body with a high content of magnetic phase according to claim 1, characterized in that The light guide fibers are one or more of SiO2 fibers, glass fibers, PMMA fibers, polycarbonate fibers, polyethylene terephthalate fibers, cellulose nanofibers, polystyrene fibers and TPU fibers.

3. The method for preparing a magnetoelastic body with a high content of magnetic phase according to claim 1, characterized in that The magnetic material is one of NdFeB, ferrite, SmCo, MnBi, Fe-Co, CIP, Fe-Ni and samarium iron nitride.

4. The method of claim 1, wherein the magnetoelastic material has a high magnetic phase content. The resin is one of Agilus30, soft glue, esun elastic resin, e600 resin, polyurethane-acrylate elastic resin.

5. The method of claim 1, wherein the magnetoelastic material has a high magnetic phase content. When the light guide raw material is silica raw material with a diameter of 5 microns, the mass ratio of the light guide fibers is 3 wt.%.

6. The method of claim 1, wherein the magnetoelastic material has a high magnetic phase content. The method for breaking the light guide raw material is to place the light guide raw material in a ball mill tank for wet ball milling for 30-40 minutes at a rotation speed of 200-400 rpm.

7. The method of claim 1, wherein the magnetoelastic material has a high magnetic phase content. During the stirring of the magnetic material powder, the resin and the light guide fibers in the vacuum homogenizer, the stirring speed is 1500 rpm-2500 rpm.

8. A magnetoelastic body having a high content of magnetic phase, characterized in that, The method for preparing a magnetoelastic body with a high content of magnetic phase according to claim 1, characterized in that 9. A magnetic sensor, characterized by The method comprises the following steps:

10. An electronic skin, characterized by, The method comprises the following steps:

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