Flexible polymer magnetic film origami local design method and flexible force sensor

Abstract

The invention discloses a flexible polymer magnetic film paper folding local design method and a flexible force sensor, and the method comprises the steps: drawing a fold shape expected to be obtained by a flexible polymer magnetic film into a plane graph; a mold three-dimensional diagram is manufactured based on the planar graph, and 3d printing is carried out; preparing a solution of magnetic substance powder and a silica gel mixture PDMS, mixing a PDMS prepolymer and a curing agent according to a first preset proportion to obtain the silica gel mixture PDMS, then adding the magnetic substance powder and the silica gel mixture PDMS according to a second preset proportion, fully stirring, pouring the solution into one side of a mold, and carrying out mold pressing to obtain the magnetic composite material. The scraper blade scrapes the mold to uniformly distribute the magnetic material powder particles; placing the mold in a state of 80 DEG C for curing for 2 hours, after the mold is completely cured, slowly demolding from the edge to obtain a flexible polymer magnetic film with a crease, then folding the flexible polymer magnetic film, and placing the flexible polymer magnetic film in a magnetic field for magnetization to obtain a magnetic field related to a folding mode and a magnetization direction.

Description

Technical Field

[0001] The present invention relates to the fields of flexible skin, mechanical perception, soft robots and biomedical technology, and in particular to a method for origami-based local design of a flexible polymer magnetic film and a flexible force-sensitive sensor. Background Art

[0002] Flexible magnetic film refers to a soft film that is solidified by mixing hard magnetic powder and silicone. Flexible force-sensitive sensor is a flexible electronic device used to sense the distribution of surface contact stress. It has broad application prospects in the fields of robotics, biomechanics and medical measurement. It has the potential for reshaping, consistency, non-contact sensing and navigation, and is gradually gaining attention. In theory, the residual magnetic field distribution inside the magnetic film has strong programmability. Some scholars have used this to design sinusoidal magnetic fields and centripetal magnetic fields to achieve the perception and decoupling of multi-dimensional force information. For the multi-point multi-dimensional force perception of large-area flexible magnetic films, more complex magnetic field distributions need to be designed. The existing magnetic field of the magnetic film is relatively regular, but it has developed towards anisotropic magnetic fields. The existing magnetic field is mainly sinusoidal magnetization and centripetal magnetization. It can be seen that the magnetic field of the magnetic film is highly designable and has great potential in this regard. Some scholars have proposed a method of placing the magnetic film in a designed fixture to magnetize it to obtain the target magnetic field. Now another method is proposed, which can save efficiency based on the idea of ​​folding paper and also improve the tensile properties of the magnetic film.

[0003] The information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0004] In view of the shortcomings or defects of the above-mentioned prior art, a flexible polymer magnetic film origami local design method and a flexible force-sensitive sensor are provided, which change the magnetic field distribution based on the idea of ​​folding and cutting paper to obtain more available magnetic field positions for decoupling of subsequent information.

[0005] The purpose of the present invention is achieved through the following technical solutions.

[0006] A method for origami-based local design of a flexible polymer magnetic film includes: Drawing the desired crease shape of the flexible polymer magnetic film into a plane diagram; Based on the plan view, a three-dimensional drawing of the mold is produced and 3D printed, and a release agent is sprayed on the surface of the mold to facilitate subsequent demoulding; A solution of magnetic substance powder and silica gel mixture PDMS is prepared, PDMS prepolymer and curing agent are mixed in a first predetermined ratio to obtain silica gel mixture PDMS, and then magnetic substance powder and the silica gel mixture PDMS in a second predetermined ratio are added and stirred sufficiently, and then placed in a vacuum box and evacuated until bubbles disappear, and then maintained in a vacuum state for 30 minutes; Pour the solution into one side of the mold and scrape the mold with a scraper to make the magnetic substance powder particles evenly distributed; The mold was placed at 80°C for curing for 2 hours. After it was completely cured, it was slowly demolded from the edge to obtain a flexible polymer magnetic film with creases. The flexible polymer magnetic film was then folded and placed in a magnetic field for magnetization to obtain a magnetic field related to the folding method and magnetization direction.

[0007] In the method, the first predetermined ratio is 10:1, 15:1 or 20:1 to mix the PDMS prepolymer and the curing agent.

[0008] In the method, the second predetermined ratio is 1:1, 2:1 or 3:1 to mix the magnetic substance and the silica gel mixture PDMS.

[0009] In the method, the scraper and the mold are scraped at an angle of 45 degrees to ensure uniform distribution of magnetic material powder particles.

[0010] In the method, the magnetization direction is perpendicular to the flexible polymer magnetic film or parallel to the flexible polymer magnetic film.

[0011] In the method, the magnetic field for magnetization is such that the magnetic material exhibits an overall directional residual magnetic field after magnetization.

[0012] In the method described, if the direction of the magnetic field at the fold of the flexible polymer magnetic film is at an angle to the crease, then there is a magnetic field direction perpendicular to the crease at the crease, which will present a sinusoidal magnetic field distribution after unfolding.

[0013] In the method, the fold shape includes a fan shape, a cross shape or a rice shape.

[0014] A flexible polymer magnetic film has a magnetic field obtained by the method.

[0015] A flexible force-sensitive sensor comprises the flexible polymer magnetic film.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention puts a mixture of magnetic material powder and silica gel PDMS into a mold with a crease mark to obtain a magnetic film with the crease, and then magnetizes the folded magnetic film. According to different magnetization directions, the magnetic field changes regularly along the crease in the x, y and z directions, and the existence of the crease enables the magnetic film to locally withstand a larger curvature, thereby improving the designability of the magnetic film and providing a technical method for the widespread use of the magnetic film.

[0017] The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to achieve the extent that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0019] In the attached picture: Figure 1 A three-dimensional image of an origami mold with the origami configuration Miura Ori; Figure 2 A three-dimensional diagram of an origami mold having an origami configuration in the shape of a cross; Figure 3 A three-dimensional image of a six-vertex water bomb origami mold with an origami configuration of Waterbomb; Figure 4 A three-dimensional diagram of an origami mold with an origami configuration that is fan-shaped and flat; Figure 5 Three-dimensional diagram of origami mold designed for general four-vertex origami parametric design; Figure 6 This is a four-vertex origami magnetic film built in the comsol simulation software; Figure 7 The z-axis magnetic field intensity distribution on the surface of the film after magnetization simulated by comsol; Figure 8 The Y-axis magnetic field intensity distribution on the surface of the film after magnetization simulated by Comsol; Fig. 9 This is the x-axis magnetic field intensity distribution on the surface of the film after magnetization simulated by comsol.

[0020] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0022] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0023] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0024] For a better understanding, Figures 1 to 9 As shown, a method for origami-based local design of a flexible polymer magnetic film includes: Drawing the desired crease shape of the flexible polymer magnetic film into a plane diagram; Based on the plan view, a three-dimensional drawing of the mold is produced and 3D printed, and a release agent is sprayed on the surface of the mold to facilitate subsequent demoulding; A solution of magnetic substance powder and silica gel mixture PDMS is prepared, PDMS prepolymer and curing agent are mixed in a first predetermined ratio to obtain silica gel mixture PDMS, and then magnetic substance powder and the silica gel mixture PDMS in a second predetermined ratio are added and stirred sufficiently, and then placed in a vacuum box and evacuated until bubbles disappear, and then maintained in a vacuum state for 30 minutes; Pour the solution into one side of the mold and scrape the mold with a scraper to make the magnetic substance powder particles evenly distributed; The mold was placed at 80°C for curing for 2 hours. After it was completely cured, it was slowly demolded from the edge to obtain a flexible polymer magnetic film with creases. The flexible polymer magnetic film was then folded and placed in a magnetic field for magnetization to obtain a magnetic field related to the folding method and magnetization direction.

[0025] In a preferred embodiment of the method, the first predetermined ratio is 10:1, 15:1 or 20:1 to mix the PDMS prepolymer and the curing agent.

[0026] In a preferred embodiment of the method, the second predetermined ratio is 1:1, 2:1 or 3:1 to mix the magnetic substance and the silica gel mixture PDMS.

[0027] In a preferred embodiment of the method, the scraper and the mold are scraped at an angle of 45° to ensure uniform distribution of magnetic material powder particles.

[0028] In a preferred embodiment of the method, the magnetization direction is perpendicular to the flexible polymer magnetic film or parallel to the flexible polymer magnetic film.

[0029] In a preferred embodiment of the method, the magnetic field in which the magnetization is performed is of a magnitude such that the magnetic material exhibits an overall directional residual magnetic field after magnetization.

[0030] In a preferred embodiment of the method, if the direction of the magnetic field at the fold of the flexible polymer magnetic film is at an angle to the fold, then there is a magnetic field direction perpendicular to the fold at the fold, which will present a sinusoidal magnetic field distribution after unfolding.

[0031] In a preferred embodiment of the method, the fold shape includes a fan shape, a cross shape or a rice shape.

[0032] A flexible polymer magnetic film has a magnetic field obtained by the method.

[0033] The flexible force-sensitive sensor comprises the flexible polymer magnetic film.

[0034] In one embodiment, a portion of material is removed from the unmagnetized magnetic film, which is then folded and magnetized in different directions of the folded magnetic film, so that complex and regular magnetic field changes can be obtained, which will produce more zero magnetic field positions and gradient change positions. In particular, when the magnetization direction is perpendicular to the fold, a sinusoidal magnetic field distribution will appear at the fold. This design method simplifies the steps of mold design for magnetization in the traditional magnetic film magnetic field magnetization process, improves the designability of the magnetic film magnetic field, and provides the possibility of magnetic film utilization.

[0035] In one embodiment, a method for origami-based local design of a flexible polymer magnetic film includes: First, draw the desired crease shape as a plane diagram. Refer to the plane drawing to make a three-dimensional drawing of the mold, and 3D print it out, and spray the release agent on the surface of the mold to facilitate subsequent demolding.

[0036] Prepare a solution of magnetic material powder and silica gel mixture PDMS. First, mix the PDMS prepolymer and curing agent in a certain ratio, then add the magnetic material powder in a ratio of 1:1, stir thoroughly, put the beaker into a vacuum box and evacuate until the bubbles disappear, then keep the vacuum state for 30 minutes.

[0037] Pour the solution into one side of the mold, and slowly scrape it with a scraper at a 45° angle to the mold to ensure that the magnetic powder particles are evenly distributed.

[0038] The mold was placed at 80°C for 2 hours.

[0039] After it is completely solidified, slowly demould from the edge to obtain a creased magnetic film, then fold the magnetic film and place it in a larger magnetic field for magnetization. The magnetization direction can be adjusted to be perpendicular to the magnetic film or parallel to the magnetic film. A larger magnetic field means that the magnetic field size can make the magnetic material present an overall directional residual magnetic field after magnetization, rather than a local directional residual magnetic field.

[0040] Obtain the magnetic field related to the folding method and magnetization direction.

[0041] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other changes to the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0042] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for origami-based local design of a flexible polymer magnetic film, characterized in that: It includes the following steps, Drawing the desired crease shape of the flexible polymer magnetic film into a plane diagram; Based on the plan view, a three-dimensional drawing of the mold is produced and 3D printed, and a release agent is sprayed on the surface of the mold to facilitate subsequent demoulding; A solution of magnetic substance powder and silica gel mixture PDMS is prepared, PDMS prepolymer and curing agent are mixed in a first predetermined ratio to obtain silica gel mixture PDMS, and then magnetic substance powder and the silica gel mixture PDMS in a second predetermined ratio are added and stirred sufficiently, and then placed in a vacuum box and evacuated until bubbles disappear, and then maintained in a vacuum state for 30 minutes; Pour the solution into one side of the mold and scrape the mold with a scraper to make the magnetic substance powder particles evenly distributed; The mold was placed at 80°C for curing for 2 hours. After it was completely cured, it was slowly demolded from the edge to obtain a flexible polymer magnetic film with creases. The flexible polymer magnetic film was then folded and placed in a magnetic field for magnetization to obtain a magnetic field related to the folding method and magnetization direction.

2. The method according to claim 1, characterized in that Preferably, the first predetermined ratio is 10:1, 15:1 or 20:1 to mix the PDMS prepolymer and the curing agent.

3. The method according to claim 1, characterized in that The second predetermined ratio is 1:1, 2:1 or 3:1 to mix the magnetic substance and the silica gel mixture PDMS.

4. The method according to claim 1, characterized in that The scraper and the mold are scraped at a 45° angle to ensure that the magnetic material powder particles are evenly distributed.

5. The method according to claim 1, characterized in that The magnetization direction is perpendicular to the flexible polymer magnetic film or parallel to the flexible polymer magnetic film.

6. The method according to claim 1, characterized in that The magnetic field under which the magnetization is carried out is such that the magnetic material exhibits an overall directional residual magnetic field after magnetization.

7. The method according to claim 1, characterized in that If the direction of the magnetic field at the fold of the flexible polymer magnetic film is at an angle to the crease, then there is a magnetic field direction perpendicular to the crease at the crease, which will present a sinusoidal magnetic field distribution after unfolding.

8. The method according to claim 1, characterized in that: The fold shape includes a fan shape, a cross shape or a rice shape.

9. A flexible polymer magnetic film, characterized in that: It has a magnetic field obtained by the method according to any one of claims 1 to 7.

10. A flexible force-sensitive sensor, characterized in that: It comprises the flexible polymer magnetic film as claimed in claim 9.

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