Device embodying magnetocaloric effect, teaching aid, anti-counterfeiting method and information encryption method

Abstract

The application provides a device, teaching aid, anti-fake method and information encryption method embodying the magnetocaloric effect. The device comprises a multi-layer structure unit and a variable frequency magnetic field generating unit; the multi-layer structure unit comprises a base layer, an information layer and a temperature-sensitive color-changing layer in sequence; the information layer comprises graphics and texts composed of magnetic materials, and the temperature-sensitive color-changing layer is composed of temperature-sensitive color-changing materials; the variable frequency magnetic field generating unit generates a magnetic field, under the action of the magnetic field, the graphics and texts in the information layer are heated due to the magnetocaloric effect, the area of the graphics and texts in the temperature-sensitive color-changing layer is colored due to the temperature rise, and the graphic and text information is obtained. The device can be used as a teaching aid to visually display the magnetocaloric effect, and can realize anti-fake, information encryption and other applications.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetocaloric effect, and particularly relates to a device embodying magnetocaloric effect, a teaching aid, a forgery prevention method and an information encryption method BACKGROUND

[0002] Magnetocaloric effect refers to the phenomenon that the temperature of ferromagnetic or paramagnetic body changes with the change of magnetic field intensity in an adiabatic process. How to make the magnetocaloric effect intuitive and easy to understand, and how to apply the magnetocaloric effect to daily life and production are topics worth studying. SUMMARY

[0003] The present application provides a device embodying magnetocaloric effect, which can intuitively display the magnetocaloric effect, can be used as a teaching aid, an entertainment product, etc., and can realize applications such as forgery prevention and information encryption.

[0004] The technical solution of the present application is: a device embodying magnetocaloric effect, comprising a multi-layer structure unit and a variable frequency magnetic field generating unit; the multi-layer structure unit comprises a base layer, an information layer and a temperature-sensitive color-changing layer;

[0005] The base layer is composed of non-magnetic material;

[0006] The information layer is located on the surface of the base layer and comprises text or patterns, referred to as a graphic text part, the graphic text part is composed of magnetic material or composite material containing magnetic material;

[0007] The temperature-sensitive color-changing layer is located on the surface of the information layer and is composed of temperature-sensitive color-changing material, used to cover the information layer, so that the graphic text information cannot be obtained through the temperature-sensitive color-changing layer before the temperature-sensitive color-changing material changes color, i.e. the graphic text information is hidden;

[0008] The variable frequency magnetic field generating unit is used to generate a magnetic field, under the action of the magnetic field, the graphic text part in the information layer is heated due to the magnetocaloric effect, causing the area covering the graphic text part in the temperature-sensitive color-changing layer to change color due to the temperature rise, and the graphic text information is obtained intuitively through the temperature-sensitive color-changing layer.

[0009] As a preferred embodiment, a cover layer is further included, the cover layer is located between the information layer and the temperature-sensitive color-changing layer and is composed of non-magnetic material, used to cover the information layer to make the surface flat.

[0010] The base layer material is not limited, such as silica gel, resin, PVC film material.

[0011] When the graphic text part is composed of magnetic material, the magnetic material is preferably magnetic powder, and more preferably soft magnetic material powder, such as ferroferric oxide powder or metal soft magnetic powder.

[0012] When the graphic-text part is composed of a composite material containing a magnetic material, the composite material is composed of a magnetic material and a non-magnetic material, wherein the magnetic material is preferably a magnetic powder, more preferably a soft magnetic material powder, such as a ferriferrous oxide powder or a metal soft magnetic powder, and the non-magnetic material is preferably silica gel, more preferably PDMS. In the composite material, the mass ratio of the magnetic material to the non-magnetic material is not limited, and the ratio can be adjusted according to one or more of the magnetic field strength, the magnetic field frequency of the variable-frequency magnetic field generating unit, and the thickness of the text and pattern. Preferably, the mass ratio of the magnetic material to the non-magnetic material is 2:1-10:1.

[0013] The method for forming the graphic-text part on the surface of the base layer is not limited, for example, one or more of casting and curing, writing, printing, and adhering.

[0014] The temperature-sensitive color-changing material changes color with temperature, including temperature-sensitive color-changing powder, temperature-sensitive color-changing ink, temperature-sensitive color-changing paint, and temperature-sensitive emulsion. Preferably, the temperature-sensitive color-changing material changes color at a temperature in the range of 40-100°C. Preferably, the initial color of the temperature-sensitive color-changing material before color change is dark, or the same as or similar to the color of the magnetic material or the composite material of the graphic-text part in the information layer, which is conducive to hiding the graphic-text information.

[0015] The magnetic field generated by the variable-frequency magnetic field generating unit satisfies a certain magnetic heating effect, so as to cause the temperature-sensitive color-changing material to change color. Preferably, the magnetic field generated by the variable-frequency magnetic field generating unit is greater than 1000 Hz, i.e., a high-frequency magnetic field.

[0016] Preferably, the magnetic field frequency and the magnetic field size of the variable-frequency magnetic field generating unit are adjustable. The greater the magnetic field frequency, the faster the color change effect occurs. The greater the magnetic field, the faster the color change effect occurs.

[0017] As an implementation, the information layer further includes a non-graphic-text part composed of a non-magnetic material in addition to the graphic-text part, and the non-graphic-text part is connected to the graphic-text part. As an implementation, the temperature-sensitive color-changing layer covers the graphic-text part and the non-graphic-text part in the information layer, so that the graphic-text information is hidden by the temperature-sensitive color-changing layer before the temperature-sensitive color-changing material changes color, and the graphic-text information cannot be obtained through the temperature-sensitive color-changing layer.

[0018] Compared with the prior art, the device of the present application has the following advantages:

[0019] (1) The device of the present application has simple structure and is easy to realize. Firstly, an information layer including graphic text part is arranged on the base layer, then the graphic text information is hidden by the color change layer. Only when the variable frequency magnetic field generating unit generates variable frequency magnetic field, the graphic text part in the information layer, which is composed of magnetic material, is heated due to the magnetic heat effect under the action of the variable frequency magnetic field, so that the temperature of the temperature-sensitive color change material covering the graphic text part is increased to cause color change. The non-graphic text part in the information layer, which is composed of non-magnetic material, does not have magnetic heat effect, so the temperature-sensitive color change material covering the non-graphic text part does not change color. Therefore, the temperature-sensitive color change layer can directly display the graphic text information after the color change of the temperature-sensitive color change material covering the graphic text part, that is, the graphic text information is obtained.

[0020] (2) The device of the present application can be used in the fields of magnetic heat effect teaching demonstration, interesting game, anti-fake, information secret transmission, etc.

[0021] For example, when used in the teaching field, the variable frequency magnetic field generating unit generates magnetic field, and the multi-layer structure unit is located in the magnetic field. The graphic text of the information layer generates magnetic heat effect, and the graphic text information in the information layer can be displayed after the color change of the temperature-sensitive color change layer, so that students can visually perceive the magnetic heat effect, which is helpful for students to understand the magnetic heat effect and has interesting nature.

[0022] When used in the anti-fake technical field, first, anti-fake information is set, and the anti-fake information is taken as the graphic text information of the information layer in the multi-layer structure unit, that is, the multi-layer structure unit carries the anti-fake information. The multi-layer structure unit carrying the anti-fake information is arranged on the article which needs to be identified. When the anti-fake information is used to identify the authenticity of the article, the variable frequency magnetic field generating unit generates magnetic field, and the multi-layer structure unit is located in the magnetic field. The graphic text of the information layer generates magnetic heat effect. If the information displayed after the color change of the temperature-sensitive color change layer is consistent with the anti-fake information, it is verified as "true", and if it is not consistent, it is verified as "false".

[0023] When used in information secret transmission, the information to be transmitted is taken as the graphic text information of the information layer in the multi-layer structure unit, that is, the multi-layer structure unit carries the transmission information. Since the information is hidden by the temperature-sensitive color change layer, the transmission process is secret transmission. After reaching the receiving end, the variable frequency magnetic field generating unit generates magnetic field, and the multi-layer structure unit is located in the magnetic field. The graphic text of the information layer generates magnetic heat effect. The information displayed after the color change of the temperature-sensitive color change layer is the transmission information, so that the information is transmitted secretly. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the device embodying the magnetic heat effect in embodiment 1 of the present application.

[0025] Figure 2 is Figure 1 is a top view of the information layer in

[0026] Figure 3 is Figure 2 is a plan view of the surface of the information layer after covering with the thermochromic layer.

[0027] Figure 4 is a plan view of the thermochromic layer after color change under the action of a magnetic field when demonstrating the magnetocaloric effect using the device in Example 1.

[0028] Figure 5 is a plan view of the information layer in Example 2 of the present application.

[0029] Figure 6 is a structural schematic diagram of the device embodying the magnetocaloric effect in Example 3 of the present application.

[0030] Figures 1-6 The reference signs in the drawings are: multilayer structure unit 100, variable frequency magnetic field generating unit 200, base layer 10, information layer 20, thermochromic layer 30, covering layer 40, graphic text part 21, non-graphic text part 22. DETAILED DESCRIPTION

[0031] The present application will be further described in detail below in conjunction with the examples and drawings. It should be noted that the following examples are intended to facilitate the understanding of the present application and do not limit the present application in any way.

[0032] Example 1:

[0033] In this example, as shown in Figure 1 , the device embodying the magnetocaloric effect is composed of a multilayer structure unit 100 and a variable frequency magnetic field generating unit 200. The multilayer structure unit 100 includes a base layer 10, an information layer 20, and a thermochromic layer 30.

[0034] The base layer 10 is cured from PDMS. The information layer 20 is located on the surface of the base layer 10, as shown in Figure 2 , and is composed of a graphic text part 21. The graphic text part 21 is composed of a composite material of PDMS and magnetic material Fe3O4, which is cured.

[0035] In this example, the graphic text part 21 is in the shape of the number "4".

[0036] The thermochromic layer 30 is located on the surface of the information layer 20 and is composed of thermochromic ink, which is used to cover the graphic text part 21 and the part outside the graphic text part, so that the graphic text information cannot be directly obtained through the thermochromic layer before the thermochromic ink changes color, i.e., the graphic text information is hidden.

[0037] The variable frequency magnetic field generating unit 200 is used to generate a magnetic field. Under the action of the magnetic field, the graphic text portion 21 in the information layer 20 is heated due to the magnetocaloric effect, causing the area covering the graphic text portion 21 in the temperature-sensitive color-changing layer 200 to change color due to the temperature rise, and the graphic text information is obtained.

[0038] In this embodiment, the manufacturing method of the multi-layer structure unit 100 is as follows:

[0039] (1) Manufacturing the base layer

[0040] The PDMS and the curing agent are mixed in a mass ratio of 10:1 and coated on a plane. The mixture is placed in an oven and dried at 80°C to obtain a base layer with a thickness of 0.5 mm.

[0041] (2) Manufacturing the information layer

[0042] The PDMS, Fe3O4 and the curing agent are mixed in a mass ratio of 10:30:1 and stirred uniformly to obtain a mixed material. The mixed material is used to write the number "4" on the surface of the base layer. Then the mixture is placed in an oven and dried at 80°C to obtain a graphic text portion with a thickness of 2 mm.

[0043] (3) Manufacturing the temperature-sensitive color-changing layer

[0044] The temperature-sensitive color-changing ink is coated on the surface of the information layer. The temperature-sensitive color-changing ink not only completely covers the number "4" in the information layer, but also covers the remaining part except the number "4". The thickness is more than 2 mm, so that the number "4" is completely hidden and the number "4" information cannot be directly obtained through the temperature-sensitive color-changing layer.

[0045] The device can demonstrate the magnetocaloric effect as a teaching aid, as follows:

[0046] The variable frequency magnetic field generating unit 200 generates a 2000 Hz high frequency magnetic field. The multi-layer structure unit 100 is located in the magnetic field. The Fe3O4 generates hysteresis loss and starts to heat up. After 1 minute, the color change of the temperature-sensitive color-changing layer is observed, as shown in Figure 4 The temperature-sensitive color-changing layer shows the graphic text information in the information layer, i.e. the number "4". Through this demonstration, the magnetocaloric effect can be directly perceived, making the magnetocaloric effect easy to understand, and the teaching is interesting.

[0047] Example 2:

[0048] In this embodiment, the device embodying the magnetocaloric effect is basically the same as that of Example 1, except that: Figure 5 As shown in

[0049] In this embodiment, the method for manufacturing the multi-layer structure unit 100 is basically the same as that in Embodiment 1, except that steps (2) and (3) are as follows:

[0050] (2) Manufacturing the information layer

[0051] The PDMS, Fe3O4 and curing agent are mixed in a mass ratio of 10:30:1 and stirred uniformly to obtain a mixed material; a mold of the number "4" is placed on the surface of the base layer, the mixed material is filled into the mold, the part outside the mold is coated with PDMS, and then placed in an oven for drying at 80°C, and then the mold is removed to obtain the graphic part and the non-graphic part, and the height of the graphic part and the non-graphic part is 2 mm.

[0052] (3) Manufacturing the thermochromic layer

[0053] The thermochromic ink is coated on the surface of the information layer, so that the thermochromic ink not only completely covers the graphic part in the information layer, but also covers the non-graphic part, with a covering thickness of 1 mm, so that the number "4" is completely hidden and the information of the number "4" cannot be obtained through the thermochromic layer.

[0054] The device can be used for anti-counterfeiting of articles, specifically as follows:

[0055] First, set the anti-counterfeiting information, for example, in this embodiment, the anti-counterfeiting information is the number "4", and the anti-counterfeiting information is taken as the graphic of the information layer in the multi-layer structure unit, i.e. the multi-layer structure unit carries the anti-counterfeiting information; the multi-layer structure unit carrying the anti-counterfeiting information is set on the article to be identified for authenticity;

[0056] When identifying the authenticity of the article by using the anti-counterfeiting information, the variable frequency magnetic field generating unit generates a magnetic field, and the multi-layer structure unit is located in the magnetic field, wherein the graphic part of the information layer generates a magnetic heat effect, if the thermochromic layer changes color to display the graphic shape in the information layer, i.e. the number "4", it is verified as "true", if the thermochromic layer does not change color or the graphic displayed after changing color is not the number "4" in the information layer, it is verified as "false".

[0057] Embodiment 3:

[0058] In this embodiment, the device for realizing the magnetic heat effect is basically the same as that in Embodiment 1, except that: Figure 6 As shown in FIG. 4, the multi-layer structure unit 100 further comprises a covering layer 40 located between the information layer 20 and the thermochromic layer 30, which is formed by curing PDMS and is used to completely cover the information layer 20 and has a flat surface.

[0059] In this embodiment, the method for manufacturing the multi-layer structure unit 100 is basically the same as that in Embodiment 1, except that steps (3) and (4) are as follows:

[0060] (3) making the covering layer

[0061] The PDMS and the curing agent are mixed uniformly at a mass ratio of 10:1, the mixed material is coated on the surface of the information layer, so that the number "4" in the information layer is completely covered, and the part other than the number "4" is covered, and the thickness of the covered number "4" is 0.5 mm.

[0062] (4) making the thermochromic layer

[0063] The thermochromic ink is coated on the surface of the covering layer with a thickness of 1 mm.

[0064] The device can be used for secret information transmission, in the embodiment, the information to be transmitted is the number "4", the information to be transmitted is taken as the graphics and texts of the information layer in the multi-layer structure unit, that is, the multi-layer structure unit carries the information to be transmitted. After reaching the receiving end, the magnetic field generating unit generates a magnetic field, so that the multi-layer structure unit is located in the magnetic field, the graphics and texts of the information layer generate a magnetic heat effect, the thermochromic layer changes color to display the number "4" in the information layer, that is, the receiving end obtains the secret information transmission.

[0065] The above embodiments are used to describe the technical solutions of the present application in detail, and it should be understood that the above description is only a specific embodiment of the present application, and is not used to limit the present application, any modification, supplement or similar replacement within the principle range of the present application should be included in the protection range of the present application.

Claims

1. A method of displaying graphic information on a direct view display using a device exhibiting the magnetocaloric effect, characterized in that: The device embodying the magnetocaloric effect comprises a multilayer structure unit and a variable frequency magnetic field generating unit; the multilayer structure unit comprises a base layer, an information layer and a temperature-sensitive color-changing layer; The base layer is made of non-magnetic material; The information layer is located on the surface of the base layer and comprises characters or patterns, referred to as graphic text part, which is made of magnetic material or composite material containing magnetic material; the information layer further comprises a non-graphic text part made of non-magnetic material in addition to the graphic text part, and the non-graphic text part is connected with the graphic text part; The temperature-sensitive color-changing layer is located on the surface of the information layer and is made of temperature-sensitive color-changing material, which is used to cover the graphic text part and the non-graphic text part in the information layer, so that the graphic text information is hidden before the temperature-sensitive color-changing material changes color and cannot be obtained through the temperature-sensitive color-changing layer; The variable frequency magnetic field generating unit is used to generate a magnetic field, under the action of the magnetic field, the graphic text part in the information layer is heated due to the magnetocaloric effect, causing the area covering the graphic text part in the temperature-sensitive color-changing layer to change color due to the temperature rise, while the non-graphic text part in the information layer does not have the magnetocaloric effect, and the area covering the non-graphic text part does not change color, so that the graphic text information can be directly obtained through the temperature-sensitive color-changing layer.

2. The method of claim 1, wherein: It further comprises a covering layer located between the information layer and the temperature-sensitive color-changing layer, which is made of non-magnetic material and is used to cover the information layer to make its surface flat.

3. The method of claim 1 wherein: The base layer material is silica gel, resin or PVC film material.

4. The method of claim 1 wherein: The magnetic material is magnetic powder.

5. The method of claim 4 wherein: The magnetic material is soft magnetic material powder.

6. The method of claim 5 wherein: The magnetic material is ferroferric oxide powder or metal soft magnetic powder.

7. The method of claim 1 wherein: The magnetic material in the composite material is magnetic powder.

8. The method of claim 7 wherein: The magnetic powder is soft magnetic material powder.

9. The method of claim 8 wherein: The magnetic powder is ferroferric oxide powder or metal soft magnetic powder.

10. The method of claim 1 wherein: The non-magnetic material is silica gel or PDMS.

11. The method of claim 1 wherein: The temperature-sensitive color-changing material is temperature-sensitive color-changing powder, temperature-sensitive color-changing ink, temperature-sensitive color-changing paint or temperature-sensitive emulsion.

12. The method of claim 1 wherein: The color-changing temperature of the temperature-sensitive color-changing material is in the range of 40-100℃.

13. The method of claim 1 wherein: The graphic text part is formed on the surface of the base layer by one or more of pouring and curing, writing, printing and pasting.

14. The method of claim 1 wherein: The magnetic field generated by the variable frequency magnetic field generating unit is greater than 1000 Hz.

15. The method of claim 1 wherein: The frequency and size of the magnetic field of the variable frequency magnetic field generating unit are adjustable.

16. An educational aid characterized by: The method of any one of claims 1 to 15 is used to embody the magnetocaloric effect.

17. A method of preventing counterfeiting, characterized by: The method of any one of claims 1 to 15 is used; First, set the anti-counterfeit information, take the anti-counterfeit information as the graphic text information of the information layer in the multilayer structure unit, that is, the multilayer structure unit carries the anti-counterfeit information; set the multilayer structure unit carrying the anti-counterfeit information on the article to be identified for authenticity; When identifying the authenticity of the article by using the anti-counterfeit information, the variable frequency magnetic field generating unit generates a magnetic field, and the multilayer structure unit is located in the magnetic field, wherein the graphic text of the information layer generates the magnetocaloric effect, if the information displayed after the temperature-sensitive color-changing layer changes color is consistent with the anti-counterfeit information, it is verified as "true", if it is not consistent, it is verified as "false".

18. An information sending method characterized by comprising: The method of any one of claims 1 to 15 is used; The information to be transmitted is taken as the graphic information of the information layer in the multi-layer structure unit, i.e. the multi-layer structure unit carries the transmitted information; after reaching the receiving end, the magnetic field generating unit generates a magnetic field, so that the multi-layer structure unit is located in the magnetic field, wherein the graphic information of the information layer generates a magnetic heat effect, and the information displayed after the temperature-sensing color-changing layer changes color is the transmitted information.

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