Smart soft material with deformation and color change function and preparation method thereof

Abstract

The application provides a smart soft material with a deformation and color change function and a preparation method thereof, and relates to the technical field of smart materials.The smart material comprises a closely combined color change layer and a driving layer; the color change layer is a protein stone photonic crystal film with structural color; the driving layer is a magnetic elastomer subjected to magnetic treatment; and the magnetic elastomer is an elastic material containing magnetic particles.The smart soft material provided by the application can simultaneously realize deformation, color change and movement by magnetic actuation, has a large response speed, is simple to control, can be remotely controlled wirelessly, and can meet different requirements.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of intelligent materials, and particularly relates to an intelligent soft material with deformation and color change functions and a preparation method thereof. BACKGROUND

[0002] Compared with traditional rigid robots, soft robots made of soft materials have become a research hotspot in the field of robots due to their high flexibility, adaptability, interactive safety and other advantages. Existing soft robots mainly rely on external stimuli such as light, temperature, humidity, pH and microfluids to drive them to deform or change color; however, the method of driving by using these stimuli sources has the problem of delayed response in the process of driving deformation or color change.

[0003] Therefore, there is an urgent need for an intelligent soft material that can quickly realize deformation and color change functions. SUMMARY

[0004] In view of the problems in the prior art, the present application provides an intelligent soft material with deformation and color change functions and a preparation method thereof. The intelligent soft material provided by the present application can realize deformation, color change and movement simultaneously by magnetic actuation, has a high response speed, is easy to control, can realize wireless remote control, and can meet different needs.

[0005] In a first aspect, the present application provides an intelligent soft material with deformation and color change functions, which comprises a closely combined color change layer and a driving layer.

[0006] The color change layer is a protein stone photonic crystal film with structural color.

[0007] The driving layer is a magnetically treated magnetic elastomer; and the magnetic elastomer is an elastic material containing magnetic particles.

[0008] Preferably, the preparation raw material of the protein stone photonic crystal film comprises an acrylate monomer, silica nanospheres, a photoinitiator and a crosslinking agent.

[0009] Preferably, the amount of the silica nanospheres is 20-40 vol% of the acrylate monomer, preferably 22-30 vol%.

[0010] The amount of the photoinitiator is 0.5-1.5 vol% of the acrylate monomer; and / or

[0011] The amount of the crosslinking agent is 0.25-1 vol% of the acrylate monomer.

[0012] Preferably, the particle size of the silica nanospheres is 140-230 nm.

[0013] Preferably, the raw materials for preparing the magnetic elastomer comprise a hard magnetic material, polydimethylsiloxane and a curing agent; preferably, the hard magnetic material is neodymium-iron-boron particles.

[0014] Preferably, the mass ratio of the hard magnetic material to the polydimethylsiloxane is (0.5-2):1, preferably (1-2):1; and / or

[0015] The mass ratio of the polydimethylsiloxane to the curing agent is (25-32):1.

[0016] Preferably, the thickness of the driving layer is greater than the thickness of the color-changing layer; preferably, the thickness of the color-changing layer is 50-600 μm; and the thickness of the driving layer is 0.8-1.5 mm.

[0017] In a second aspect, the present application provides a preparation method of the intelligent soft material of the first aspect, and the preparation method comprises:

[0018] Preparation of the color-changing layer: disperse silica nanospheres in a solution of acrylate monomers, add a photoinitiator and a crosslinking agent, mix uniformly, remove the solvent, and obtain a precursor; perform light curing on the precursor to obtain a thin film of opal photonic crystal with structural color, i.e. the color-changing layer;

[0019] Preparation of the driving layer: mix a hard magnetic material, polydimethylsiloxane and a curing agent, vacuum degassing and first curing to obtain a magnetic elastomer; perform magnetization treatment on the magnetic elastomer to obtain the driving layer;

[0020] Composite the color-changing layer and the driving layer: pour polydimethylsiloxane containing a curing agent on the surface of the driving layer, then attach the color-changing layer to the surface of the driving layer, and perform second curing to obtain the intelligent soft material.

[0021] Preferably, the temperature of the first curing is 100-140℃;

[0022] The magnetization treatment is to magnetize the magnetic elastomer using a pulsed magnetic field of 1-3 T; preferably, the magnetization treatment is in the form of one of cylindrical magnetization and spherical magnetization.

[0023] Preferably, the mass ratio of the polydimethylsiloxane to the curing agent is (25-32):1;

[0024] The temperature of the second curing is 100-140℃.

[0025] Compared with the prior art, the present application has at least the following beneficial effects:

[0026] The application provides a smart soft material with deformation and color change functions, which has a three-dimensional opal photonic crystal film with structural color as a color change layer, and can reversibly change color when deformed under force; and has a magnetically treated magnetic elastomer as a driving layer, which can be deformed under the action of an actuating magnetic field to realize various motion modes; since the color change layer and the driving layer are closely combined, when the driving layer is deformed to generate strain, the strain will act on the color change layer, so that the color change layer is deformed to change color.

[0027] The smart soft material provided by the application can realize various motion modes by changing the direction of the actuating magnetic field and the magnetization method, and the driving layer is deformed to generate strain during motion, which further acts on the color change layer to make the color change layer cross different colors during tension and compression, so that various color changes can be realized. The smart soft material can realize deformation, color change and motion simultaneously by magnetic actuation, has high response speed, is simple to control, can be remotely controlled wirelessly, and can meet different requirements. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0029] Figure 1 is a tensile fracture diagram of the photonic crystal film with different crosslinker contents provided by the application;

[0030] Figure 2 is a tensile fracture diagram of the driving layer with different curing agent contents provided by the application;

[0031] Figure 3 is a preparation flowchart of the smart soft material provided by the application;

[0032] Figure 4 is a magnetization treatment method schematic diagram in the preparation process of the driving layer provided by the application;

[0033] Figure 5 is a spectrum change diagram of the photonic crystal film in the tensile process provided by the application embodiment 1-2;

[0034] Figure 6 is a color change diagram of the photonic crystal film in the tensile process provided by the application embodiment 1-2;

[0035] Figure 7 is a deformation and color change diagram of the smart soft material under the action of the magnetic field provided by the application embodiment 1. DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be clearly and completely described with the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0037] In a first aspect, the present application provides a smart soft material with deformation and color change functions, which comprises a closely combined color change layer and driving layer.

[0038] The color change layer is a protein stone photonic crystal film with structural color.

[0039] The driving layer is a magnetic elastomer subjected to magnetization treatment; and the magnetic elastomer is an elastic material containing magnetic particles.

[0040] The present application provides a smart soft material with deformation and color change functions, which uses a three-dimensional protein stone photonic crystal film with structural color as the color change layer, and can change color reversibly when deformed under stress; and uses a magnetic elastomer subjected to magnetization treatment as the driving layer, which can be deformed under the action of an actuating magnetic field to realize various motion modes; since the color change layer and the driving layer are closely combined, when the driving layer is deformed to generate strain, the strain will act on the color change layer, so that the color change layer is deformed to change color.

[0041] The smart soft material provided by the present application can realize various motion modes by changing the direction of the actuating magnetic field and the magnetization method, and the driving layer is deformed to generate strain during the motion, which further acts on the color change layer to make the color change layer cross different colors during tension and compression, so that various color changes can be realized. The smart soft material can realize deformation, color change and motion simultaneously by magnetic actuation, has a high response speed, is easy to control, can be remotely controlled wirelessly, and can meet different requirements.

[0042] According to some preferred embodiments, the preparation raw materials of the protein stone photonic crystal film include acrylate monomers, silica nanospheres, a photoinitiator and a crosslinking agent.

[0043] According to some preferred embodiments, the amount of the silica nanospheres is 20-40 vol% (for example, it can be 20 vol%, 22 vol%, 25 vol%, 26 vol%, 28 vol%, 30 vol%, 32 vol%, 34 vol%, 36 vol%, 38 vol% or 40 vol%), preferably 22-30 vol% (for example, it can be 22 vol%, 25 vol%, 26 vol%, 28 vol% or 30 vol%) of the acrylate monomers; the acrylate monomers of the present application are preferably acrylates containing one carbon-carbon double bond.

[0044] The amount of the photoinitiator is 0.5-1.5 vol% (for example, it can be 0.5 vol%, 0.6 vol%, 0.8 vol%, 0.9 vol%, 1 vol%, 1.2 vol%, 1.4 vol% or 1.5 vol%) of the acrylate monomers; and / or

[0045] The amount of the crosslinking agent is 0.25-1 vol% (for example, it can be 0.25 vol%, 0.3 vol%, 0.35 vol%, 0.4 vol%, 0.45 vol%, 0.5 vol%, 0.55 vol%, 0.6 vol%, 0.65 vol%, 0.7 vol%, 0.75 vol%, 0.8 vol%, 0.85 vol%, 0.9 vol%, 0.95 vol% or 1 vol%) of the acrylate monomers. The acrylate crosslinking agent of the present application preferably contains two carbon-carbon double bonds. The present application studies the effect of different crosslinking agent contents on the mechanical properties of the photonic crystal thin film, and finds that the addition of the crosslinking agent can improve the mechanical properties of the photonic crystal thin film, and as the crosslinking agent increases, the breaking strength increases, the elongation decreases, and the elastic modulus increases. Figure 1 The tensile fracture diagram of the photonic crystal thin film with different crosslinking agent contents can obtain the elastic modulus of the photonic crystal thin film with different crosslinking agent contents, when the crosslinking agent content is 0 Vol%, the modulus is 0.0891 MPa; when the crosslinking agent content is 0.5 Vol%, the modulus is 0.17 MPa; when the crosslinking agent content is 1 Vol%, the modulus is 0.265 MPa; it should be noted that the elastic modulus is calculated from the linear change under low strain.

[0046] According to some preferred embodiments, the particle size of the silica nanospheres is 140-230 mm (for example, it can be 140 nm, 145 nm, 150 nm, 155 nm, 160 nm, 165 nm, 170 nm, 175 nm, 180 nm, 185 nm, 189 nm, 195 nm, 200 nm, 205 nm, 207 nm, 210 nm, 215 nm, 218 nm, 220 nm, 225 nm, 230 nm, or 230 nm).

[0047] The present application uses acrylate monomers, silica nanospheres, photoinitiators, and cross-linking agents as main raw materials to prepare a three-dimensional protein photonic crystal film with structural color as a color-changing layer. Preferably, the three-dimensional protein photonic crystal film with structural color is prepared using the above-mentioned amounts of raw materials. Further, under the condition that the amounts of other raw materials are the same, the structural color of the photonic crystal film is adjusted by the particle size of the silica nanospheres. For example, when the amount of silica nanospheres is 25 vol% of the acrylate monomers, the structural color of the protein photonic crystal film prepared using silica nanospheres with a particle size of 189 nm is yellow, and the structural color of the protein photonic crystal film prepared using silica nanospheres with a particle size of 207 nm is red. Similarly, photonic crystal films with other structural colors can be prepared according to actual needs.

[0048] According to some preferred embodiments, the raw materials for preparing the magnetic elastomer include hard magnetic materials, polydimethylsiloxane, and curing agents. Preferably, the hard magnetic materials are neodymium iron boron microparticles. More preferably, the particle size of the neodymium iron boron microparticles is 5-50 μm (for example, it can be 5 μm, 8 μm, 10 μm, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm), and preferably 5 μm.

[0049] According to some preferred embodiments, the mass ratio of the hard magnetic materials to the polydimethylsiloxane is (0.5-2):1 (for example, it can be 0.5:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.6:1, 1.8:1, or 2:1), and preferably (1-2):1 (for example, it can be 1:1, 1.2:1, 1.5:1, 1.6:1, 1.8:1, or 2:1).

[0050] Further, the present application uses neodymium-iron-boron microparticles (as a hard magnetic material), polydimethylsiloxane and a curing agent as main raw materials to prepare a magnetic elastomer containing magnetic particles, then uses the magnetized magnetic elastomer as a driving layer, and studies the influence of different mass ratios of neodymium-iron-boron microparticles (NdFeB) and polydimethylsiloxane (PDMS) on the magnetic properties of the driving layer, and it is found that, under the condition that the amounts of other raw materials are the same, as the content of NdFeB increases, the magnetic moment density of the magnetized sample increases, and the magnetization degree has a good linear relationship with the content of neodymium-iron-boron microparticles; when more neodymium-iron-boron microparticles are embedded, it is beneficial to obtain higher magnetic strength; when the mass ratio of neodymium-iron-boron microparticles and polydimethylsiloxane is 0.5:1, the magnetic moment density of the magnetized sample is from 35.94kAm -1 ; when the mass ratio of neodymium-iron-boron microparticles and polydimethylsiloxane is 1:1, the magnetic moment density of the magnetized sample is from 71.55kAm -1 ; when the mass ratio of neodymium-iron-boron microparticles and polydimethylsiloxane is 1.5:1, the magnetic moment density of the magnetized sample is from 98.23kAm -1 ; when the mass ratio of neodymium-iron-boron microparticles and polydimethylsiloxane is 2:1, the magnetic moment density of the magnetized sample is from 131.8kAm -1 ; and continuing to increase the content of NdFeB will make the material viscous, which will increase the difficulty of preparing the elastic material. In order to ensure that the driving layer can deform under the driving of the magnetic field and drive the color change layer to change color, the mass ratio of neodymium-iron-boron microparticles to polydimethylsiloxane in the present application is (0.5-2):1, preferably (1-2):1. and / or

[0051] The mass ratio of the polydimethylsiloxane to the curing agent is (25-32):1 (for example, it can be 25:1, 26:1, 27:1, 28:1, 29:1, 30:1, 31:1 or 32:1). In order to ensure better matching of the elastic modulus of the color change layer and the driving layer, the mass ratio of polydimethylsiloxane to curing agent is preferably (25-32):1.

[0052] The curing agent of the present application is a polydimethylsiloxane curing agent, and the influence of the mass ratio of polydimethylsiloxane (PDMS) to the curing agent on the mechanical properties of the driving layer is studied, and it is found that, under the condition that the mass ratio of neodymium-iron-boron microparticles and polydimethylsiloxane is the same, the mass ratio of PDMS to the curing agent has a great influence on the mechanical properties of the magnetic elastomer. By Figure 2The tensile fracture diagram of the driving layer with different contents of the curing agent can obtain the elastic modulus of the driving layer with different contents of the curing agent. When the mass ratio of PDMS to the curing agent is 10:1, the elastic modulus is 1.296 MPa without adding NdFeB, and the elastic modulus is 1.439 MPa with adding NdFeB; when the mass ratio of PDMS to the curing agent is 20:1, the elastic modulus is 0.344 MPa without adding NdFeB, and the elastic modulus is 0.374 MPa with adding NdFeB; when the mass ratio of PDMS to the curing agent is 30:1, the elastic modulus is 0.142 MPa without adding NdFeB, and the elastic modulus is 0.185 MPa with adding NdFeB; thus, it can be seen that the elastic modulus of the elastomer is not greatly affected after adding NdFeB under the same mass ratio of PDMS to the curing agent. It should be noted that when the neodymium iron boron particles are added, the mass ratio of neodymium iron boron particles to polydimethylsiloxane is 1.5:1, Figure 2 PDMS 10:1 PDMS 10:1 +NdFeB represents the tensile fracture diagram of PDMS with a mass ratio of 10:1 to the curing agent with adding NdFeB; and the like.

[0053] In some more preferred embodiments of the present application, the elastic modulus of the color-changing layer and the driving layer is equivalent, and the difference between the elastic modulus of the two is not more than 0.05 MPa, and under the action of the magnetic field, the driving layer and the color-changing layer will deform in a more similar manner, which can effectively reduce the stress concentration.

[0054] According to some preferred embodiments, the thickness of the driving layer is greater than that of the color-changing layer; preferably, the thickness of the color-changing layer is 50-600 μm (for example, it can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm or 600 μm); and the thickness of the driving layer is 0.8-1.5 mm (for example, it can be 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm). The driving layer of the present application is preferably a driving layer with a millimeter-level thickness, which can generate a more obvious strain effect to drive the color-changing layer to change color.

[0055] As Figure 3 shown in the second aspect, the present application provides a preparation method of the intelligent soft material of the first aspect, and the preparation method comprises:

[0056] Preparation of the color-changing layer: disperse the silica nanospheres in a solution of the acrylate monomer, and add a photoinitiator and a crosslinking agent, mix well, remove the solvent, and obtain a precursor; perform light curing on the precursor to obtain a thin film of opal photonic crystal with structural color, i.e., the color-changing layer;

[0057] Preparation of the driving layer: mix a hard magnetic material, polydimethylsiloxane, and a curing agent, vacuum-deaerate, and first cure to obtain a magnetic elastomer; perform magnetization treatment on the magnetic elastomer to obtain the driving layer;

[0058] Composite color-changing layer and driving layer: pour polydimethylsiloxane containing a curing agent on the surface of the driving layer, then attach the color-changing layer to the surface of the driving layer, and perform second curing to obtain the smart soft material.

[0059] The present application first mixes silica nanospheres, an acrylate monomer, a photoinitiator, and a crosslinking agent well, performs light curing to obtain a thin film of three-dimensional opal photonic crystal with structural color, i.e., the color-changing layer; then uses neodymium-iron-boron particles, polydimethylsiloxane, and a curing agent as main raw materials to obtain a magnetic elastomer containing magnetic particles, and performs magnetization treatment on the magnetic elastomer to obtain the driving layer; finally, the color-changing layer and the driving layer are combined to obtain the smart soft material.

[0060] In some preferred embodiments, the preparation of the color-changing layer comprises: dispersing silica nanospheres in a solution of an acrylate monomer, wherein the amount of the silica nanospheres is 20-40 vol% of the acrylate monomer, preferably 22-30 vol%; the solution of the acrylate monomer is an ethanol solution of the acrylate monomer; then adding a photoinitiator and a crosslinking agent, mixing well, and removing the solvent to obtain a precursor; wherein the amount of the photoinitiator is 0.5-1.5 vol% of the acrylate monomer; the amount of the crosslinking agent is 0.25-1 vol% of the acrylate monomer; the temperature and time for removing the solvent are not specifically limited, as long as the solvent can be removed without causing loss of the acrylate monomer; the precursor is irradiated with ultraviolet light for light curing to obtain a thin film of opal photonic crystal with structural color, i.e., the color-changing layer; the ultraviolet light intensity and irradiation time in the light curing process are not specifically limited, as long as the curing requirements can be met.

[0061] According to some preferred embodiments, the first curing temperature is 100-140℃ (for example, it can be 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃ or 140℃), and the curing time of the present application can be adjusted according to the curing temperature, and the curing time is preferably 10min-60min (for example, it can be 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min or 60min);

[0062] The magnetization treatment is to magnetize the magnetic elastomer by using a pulsed magnetic field of 1-3T; preferably, the magnetization treatment is in the form of one of cylindrical magnetization and spherical magnetization.

[0063] The magnetization method adopted by the present application is as shown in Figure 4 The specific process of cylindrical magnetization includes: winding the prepared rectangular magnetic elastomer around a cylinder by one and a half turns, magnetizing it using a pulsed magnetic field, and after unfolding it, a sinusoidal magnetization curve can be formed on the cross section in the length direction of the sample, which can be transformed into a sinusoidal shape under the action of an actuating magnetic field, so that the surface stress distribution changes in a gradient manner. For the above-mentioned cylindrical magnetization method, after applying an actuating magnetic field, during movement, the wave peak of the bending part will be subjected to tensile stress, and the corresponding color-changing layer will change from the initial yellow color to blue-green color, and the reflection wavelength will be blue-shifted; similarly, the wave valley part is subjected to compressive stress, and the corresponding color-changing layer changes from the initial yellow color to red color, and red shift occurs, and finally a colorful color change is presented. With the change of the direction of the actuating magnetic field, the intelligent soft material can crawl forward in a peristaltic manner.

[0064] The specific process of spherical magnetization in this invention includes: fixing the prepared circular magnetic elastomer onto a sphere, magnetizing it using a pulsed magnetic field, and unfolding it to form a semi-sine wave magnetization curve on each cross-section of the sample that exceeds the diameter, exhibiting a ring distribution centered on the center, resulting in a uniform strain distribution on its surface. For the above spherical magnetization method, when the applied actuating magnetic field is upward, the intelligent soft material bulges upward into a hemispherical shape. At this time, the color-changing layer is subjected to uniform tensile stress, and the strain increases with the increase of the actuating magnetic field, with the color gradually changing from yellow to green and then to blue. Conversely, when the applied actuating magnetic field is downward, the device is concave downward into a hemispherical shape. At this time, the upper surface is compressed, and the color gradually changes from yellow to red, resulting in a redshift. By changing the direction of the actuating magnetic field, the color can be changed from red to almost the entire visible light region, spanning from blue to violet. Placing four typical colors (red / yellow / green / blue) on a solid-color background provides good background matching, and because these deformations are subjected to uniform strain under a certain magnetic field, the color presented on the surface of the intelligent soft material is also uniform in an ideal environment. Compared with cylindrical magnetization, spherical magnetization results in greater strain and more uniform color.

[0065] In some preferred embodiments, the preparation of the driving layer includes: mixing neodymium iron boron microparticles, polydimethylsiloxane, and a curing agent, wherein the ratio of neodymium iron boron microparticles to polydimethylsiloxane is (0.5–2):1, preferably (1–2):1; the mass ratio of polydimethylsiloxane to curing agent is (25–32):1; then, after vacuum degassing, the mixture is placed in a mold for first curing (curing at 100–140°C) to obtain a magnetic elastomer; the elastomer is placed in a magnetizer and magnetized using a pulsed magnetic field of 1–3T to obtain the driving layer. This invention does not specifically limit the shape and thickness of the mold, which can be selected according to actual needs; the shape of the magnetic elastomer can be cut according to requirements.

[0066] According to some preferred embodiments, the mass ratio of the polydimethylsiloxane to the curing agent is (25-32):1;

[0067] The second curing temperature is 100-140℃ (for example, it can be 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃ or 140℃). The curing time of the present invention can be adjusted according to the curing temperature. The curing time is preferably 10min-60min (for example, it can be 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min or 60min).

[0068] After separately preparing the color-changing layer and the driving layer, this invention forms a layer to be cured by pouring polydimethylsiloxane containing a curing agent onto the surface of the driving layer; and then attaches the color-changing layer to the surface of the layer to be cured for a second curing, which can ensure a tighter bond between the color-changing layer and the driving layer in the obtained smart soft material.

[0069] To more clearly illustrate the technical solution and advantages of the present invention, the present invention will be further described below in conjunction with embodiments.

[0070] The materials and reagents used in this invention can all be purchased commercially or synthesized in-house, and there are no restrictions on the specific models. It should be noted that the volume of the SiO2 nanospheres in this invention is calculated from their mass and density.

[0071] Example 1

[0072] Preparation of the color-changing layer: 0.02 mL of 189 nm SiO2 nanospheres were dispersed in an ethanol solution of acrylate monomers. Then, 2-hydroxy-2-methylphenylacetone (1173) was added as a photoinitiator and PEGDA as a crosslinking agent, and the mixture was stirred to obtain a mixed solution. The volume of 2-hydroxy-2-methylphenylacetone was 1% of the total volume of the acrylate monomers, the volume of polyethylene glycol diacrylate (PEGDA) was 0.5% of the total volume of the acrylate monomers, and the ethanol solution of the acrylate monomers contained 0.03 mL of diethyl acrylate. An ethanol solution of polyethylene glycol ethyl ether acrylate (DEGEEA) and 0.03 mL of polyethylene glycol phenyl ether acrylate (PEGPEA) was prepared. The mixture was placed in an 80°C oven to completely remove the ethanol, yielding 0.08 mL of precursor. Polyimide tape was then applied to two glass slides to create a 200 μm gap, allowing the precursor to penetrate between the two glass slides. Finally, the mixture was cured under ultraviolet light for 50 s to obtain a three-dimensional opal photonic crystal film with a yellow structural color, i.e., a color-changing layer. The elastic modulus of this photonic crystal film is 0.17 MPa.

[0073] Preparation of the driving layer: Neodymium iron boron microparticles and polydimethylsiloxane (PDMS) were mixed evenly at a mass ratio of 1.5:1, and then PDMS curing agent was added. The mass ratio of PDMS to PDMS curing agent was 30:1. After stirring evenly, vacuum degassing was performed using a vacuum dryer. Then, it was poured into a mold with a thickness of 1 mm. Excess residual liquid was removed with a scraper to control the thickness. After curing, it was cured in an oven at 110℃ for 20 min. After curing, it was cut into a preset pattern. Then, the elastomer was bent and fixed into a preset shape. Finally, it was placed in a magnetizer and magnetized using a 1-3T pulsed magnetic field in a spherical magnetization method to obtain the driving layer. The elastic modulus of the driving layer is 0.185 MPa.

[0074] Composite color-changing layer and driving layer: A layer of polydimethylsiloxane (PDMS) containing PDMS curing agent is poured onto the driving layer. The mass ratio of polydimethylsiloxane (PDMS) to PDMS curing agent is 30:1. Then, the color-changing layer is attached to the surface of the PDMS layer and cured in an oven at 110°C for 20 minutes to obtain the smart soft material.

[0075] Example 2

[0076] Preparation of the color-changing layer: 0.02 mL of 207 nm SiO2 nanospheres were dispersed in an ethanol solution of acrylate monomers. Then, 2-hydroxy-2-methylphenylacetone (1173) was added as a photoinitiator and PEGDA as a crosslinking agent, and the mixture was stirred to obtain a mixed solution. The volume of 2-hydroxy-2-methylphenylacetone was 1% of the total volume of the acrylate monomers, the volume of polyethylene glycol diacrylate (PEGDA) was 0.5% of the total volume of the acrylate monomers, and the ethanol solution of the acrylate monomers contained 0.03 mL of diethyl acrylate. An ethanol solution of polyethylene glycol ethyl ether acrylate (DEGEEA) and 0.03 mL of polyethylene glycol phenyl ether acrylate (PEGPEA) was prepared. The mixture was placed in an 80°C oven to completely remove the ethanol, yielding 0.08 mL of precursor. Polyimide tape was then applied to two glass slides to create a 200 μm gap, allowing the precursor to penetrate between the two glass slides. Finally, the mixture was cured under ultraviolet light for 50 s to obtain a three-dimensional opal photonic crystal film with a red structural color, i.e., a color-changing layer. The elastic modulus of this photonic crystal film is 0.17 MPa.

[0077] Preparation of the driving layer: Neodymium iron boron microparticles and polydimethylsiloxane (PDMS) were mixed evenly at a mass ratio of 1.5:1, and then PDMS curing agent was added. The mass ratio of PDMS to PDMS curing agent was 30:1. After stirring evenly, vacuum degassing was performed using a vacuum dryer. Then, it was poured into a mold with a thickness of 1 mm. Excess residual liquid was removed with a scraper to control the thickness. After curing, it was cured in an oven at 110℃ for 20 min. After curing, it was cut into a preset pattern. Then, the elastomer was bent and fixed into a preset shape. Finally, it was placed in a magnetizer and magnetized using a 1-3T pulsed magnetic field in a spherical magnetization method to obtain the driving layer. The elastic modulus of the driving layer is 0.185 MPa.

[0078] Composite color-changing layer and driving layer: A layer of polydimethylsiloxane (PDMS) containing PDMS curing agent is poured onto the driving layer. The mass ratio of polydimethylsiloxane (PDMS) to PDMS curing agent is 30:1. Then, the color-changing layer is attached to the surface of the PDMS layer and cured in an oven at 110°C for 20 minutes to obtain the smart soft material.

[0079] The spectral changes of the photonic crystal thin films of Example 1 (structural color: yellow) and Example 2 (structural color: red) during the stretching process are as follows: Figure 5 As shown, the wavelengths of both films exhibit a blue shift during the stretching process, and the strain sensitivity Δλ / Δε is independent of the initial color, with a value of approximately 2.2 nm / % when a linear change is assumed.

[0080] The color changes of the photonic crystal thin films of Example 1 (structural color: yellow) and Example 2 (structural color: red) during stretching are as follows: Figure 6 As shown, the two films can change color across different colors during the stretching process.

[0081] The present invention describes the deformation and color change process of the intelligent soft material prepared in Example 1 under an actuating magnetic field as follows: Figure 7 As shown, under the influence of a magnetic field, this intelligent soft material deforms. Changing the direction of the magnetic field alters the material's deformation state, causing it to move forward like a caterpillar. Simultaneously, during tension and compression, the color-changing layer displays different colors, achieving a color change across almost the entire visible light spectrum, from red to blue-violet. This intelligent soft material can simultaneously deform, change color, and move under an actuating magnetic field, exhibiting fast response, simple control, and wireless remote control capabilities, thus meeting diverse needs.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A smart soft material with deformation and color-changing function, characterized in that, The intelligent software material includes a tightly bonded color-changing layer and a driving layer; The color-changing layer is an opal photonic crystal thin film with structural color; the color-changing layer undergoes a reversible color change when deformed under stress. The driving layer is a magnetized magnetic elastomer; the magnetic elastomer is an elastic material containing magnetic particles.

2. The intelligent soft material according to claim 1, characterized in that, The raw materials for preparing the opal photonic crystal thin film include acrylate monomers, silica nanospheres, photoinitiators, and crosslinking agents.

3. The intelligent soft material according to claim 2, characterized in that, The amount of the silica nanospheres used is 20-40 vol% of the acrylate monomer. The amount of the photoinitiator is 0.5~1.5 vol% of the acrylate monomer; and / or The amount of the crosslinking agent is 0.25~1 vol of the acrylate monomer.

4. The intelligent soft material according to claim 3, characterized in that, The amount of silica nanospheres used is 22-30 vol of the acrylate monomer.

5. The intelligent soft material according to claim 2, characterized in that, The silica nanospheres have a particle size of 140~230 nm.

6. The intelligent soft material according to claim 1, characterized in that, The raw materials for preparing the magnetic elastomer include hard magnetic materials, polydimethylsiloxane, and a curing agent.

7. The intelligent soft material according to claim 6, characterized in that, The hard magnetic material is neodymium iron boron microparticles.

8. The intelligent soft material according to claim 6, characterized in that, The mass ratio of the hard magnetic material to the polydimethylsiloxane is (0.5~2):1; and / or The mass ratio of the polydimethylsiloxane to the curing agent is (25~32):

1.

9. The intelligent soft material according to claim 8, characterized in that, The mass ratio of the hard magnetic material to the polydimethylsiloxane is (1~2):

1.

10. The intelligent soft material according to claim 1, characterized in that, The thickness of the driving layer is greater than the thickness of the color-changing layer.

11. The intelligent soft material according to claim 10, characterized in that, The thickness of the color-changing layer is 50~600μm; the thickness of the driving layer is 0.8~1.5mm.

12. A method for preparing the intelligent soft material according to any one of claims 1-11, characterized in that, The preparation method includes: Preparation of the color-changing layer: Silica nanospheres are dispersed in a solution of acrylate monomers, and photoinitiator and crosslinking agent are added and mixed. The solvent is removed to obtain a precursor. The precursor is photocured to obtain an opal photonic crystal film with structural color, i.e., the color-changing layer. Preparation of the driving layer: Hard magnetic material, polydimethylsiloxane, and curing agent are mixed and then subjected to vacuum degassing and first curing to obtain a magnetic elastomer; the magnetic elastomer is then magnetized to obtain the driving layer; Composite color-changing layer and driving layer: Polydimethylsiloxane containing a curing agent is poured onto the surface of the driving layer, and then the color-changing layer is attached to the surface of the driving layer for a second curing to obtain the smart soft material.

13. The preparation method according to claim 12, characterized in that, The first curing temperature is 100~140℃; The magnetization process involves magnetizing the magnetic elastomer using a pulsed magnetic field of 1-3T; the magnetization process can be performed using either cylindrical magnetization or spherical magnetization.

14. The preparation method according to claim 12, characterized in that, The mass ratio of the polydimethylsiloxane to the curing agent is (25~32):1; The second curing temperature is 100~140℃.

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