Stretchable strain materials with robust interfaces and methods of making the same

Abstract

The application provides a stretchable strain material with a robust interface and a preparation method thereof, and the preparation method comprises the following steps: preparing a first composite material and a second composite material with different dispersion forms, providing a swelling agent, respectively swelling the first edge part and the second edge part by the swelling agent, overlapping the swollen first edge part and the second edge part under the action of a first pressure, and forming a connecting part through a third solidification treatment to obtain the stretchable strain material with the robust interface. The preparation method can realize that the stretchable strain material with the robust interface can maintain good strain, conductivity and reliability at a large stretching rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flexible electronics, in particular to a stretchable strain material with robust interface and a preparation method thereof. BACKGROUND

[0002] Traditional strain sensor devices need to integrate strain sensitive components and conductive components. When integrating components with different functional characteristics, due to the differences in the inherent physical and chemical properties (chemical polarity, surface energy, surface charge, work function and energy band, etc.) of the components, there are usually weak points on the connection interface. Moreover, even if materials with different physical and chemical properties can be integrated with each other, the bonding strength and ohmic contact at the connection interface will inevitably be weakened, thereby causing interface strength and impedance problems.

[0003] In addition, if an additional adhesive layer is introduced between the sensing component and the conductive component, it will cause a large change in the electrical properties of the strain material, and even cause the device to fail. SUMMARY

[0004] In view of the above problems, the present application provides a stretchable strain material with a robust interface and a preparation method thereof, which can realize the reliability of the stretchable strain material with a robust interface under large strain conditions.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a preparation method of a stretchable strain material with a robust interface is provided, the preparation method comprising the following steps:

[0006] A first functional filler, a first polymer material and an agglomeration aid medium are provided, the first functional filler and the first polymer material are added to the agglomeration aid medium, and a first solidification treatment is performed to form a first composite material, the first composite material comprising a first base and a first edge portion;

[0007] A second functional filler, a second polymer material and a dispersion aid medium are provided, the second functional filler and the second polymer material are added to the dispersion aid medium, and a second solidification treatment is performed to form a second composite material, the second composite material comprising a second base and a second edge portion;

[0008] A swelling agent is provided, the first edge portion and the second edge portion are respectively subjected to swelling by the swelling agent, the swollen first edge portion and the second edge portion are overlapped under the action of a first pressure, and a third solidification treatment is performed to form a connecting portion, thereby obtaining the stretchable strain material with a robust interface.

[0009] In one of the embodiments, the stretchable strain material with robust interface has an elongation at break greater than or equal to 100%, and a strain sensitivity coefficient of 10-20.

[0010] In one of the embodiments, the first polymer material and the second polymer material have the same composition, and the tensile strength of the connecting portion is greater than the first polymer material, the second polymer material, and the ratio of Young's modulus of the first base portion to the second base portion is 2:1-15:1.

[0011] In one of the embodiments, the first functional filler and the second functional filler have the same composition, and the AC impedance of the connecting portion is less than 0.5% of the DC resistance value when the vibration frequency of the strain signal is 0-1 MHz, and the ratio of electrical conductivity of the first base portion to the second base portion is 1:35-1:7000.

[0012] In one of the embodiments, the auxiliary agglomeration medium includes at least one of benzene, toluene, xylene, tetrahydrofuran, chloroform, dimethyl sulfoxide;

[0013] And / or, the auxiliary dispersion medium includes at least one of polyvinylpyrrolidone, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, hexadecylamine, triton, alkyl cellulose, polyacrylic acid.

[0014] In one of the embodiments, the first functional filler includes at least one of silver nanowire, copper nanowire, graphene, carbon black;

[0015] And / or, the second functional filler includes at least one of silver nanowire, copper nanowire, graphene, carbon black;

[0016] And / or, the first polymer material includes at least one of styrene-butadiene-styrene block copolymer, polydimethylsiloxane, copolyester;

[0017] And / or, the second polymer material includes at least one of styrene-butadiene-styrene block copolymer, polydimethylsiloxane, copolyester.

[0018] In one of the embodiments, the mass ratio of the first functional filler to the first polymer material is 1:100-55:100;

[0019] And / or, the mass ratio of the second functional filler to the second polymer material is 5:100-150:100.

[0020] In one embodiment, in the step of adding the first functional filler and the first polymer material to the agglomeration medium to form the first composite material, the first dispersion is performed by a non-invasive homogenizer;

[0021] And / or, in the step of adding the second functional filler and the second polymer material to the dispersion aid to form the second composite material, the second dispersion is carried out by a three-roll homogenizer.

[0022] In one embodiment, the swelling agent includes at least one selected from methanol, ethanol, cyclohexane, n-hexane, petroleum ether, benzene, toluene, tetrahydrofuran, chloroform, and dimethyl sulfoxide.

[0023] In one embodiment, the first pressure value is 10Pa-1000Pa;

[0024] And / or, the third curing process includes a drying process, wherein the drying process is performed at a temperature of 20°C-70°C for a duration of 0.5h-24h.

[0025] According to another aspect of the present invention, a robust interface tensile strain material is provided, which is obtained by any of the above preparation methods. The robust interface tensile strain material includes a first base, a second base, and a connecting portion, wherein the connecting portion is disposed between the first base and the second base.

[0026] In one embodiment, the elongation at break of the tensile strain material with a robust interface is greater than or equal to 100%, and the strain sensitivity coefficient of the tensile strain material with a robust interface is 10-20.

[0027] And / or, the ratio of the strain sensitivity coefficients of the first base to the second base is 3:1-50:1;

[0028] And / or, the conductivity ratio of the first base to the second base is 1:35-1:7000;

[0029] And / or, the ratio of the Young's modulus of the first base to the second base is 2:1 to 15:1.

[0030] Compared with the prior art, the beneficial effects of the preparation method of the present invention are as follows:

[0031] First, by using an agglomeration aid, the first functional filler in the first composite material can be in an active agglomeration state, thereby giving the first composite material high strain sensitivity. By using a dispersion aid, the second functional filler in the second composite material can be in a monodisperse state, thereby giving the second composite material high conductivity. This invention adjusts the dispersion morphology of the first and second functional fillers to achieve a significant adjustment of the functional properties of the tensile strain material with a robust interface, thereby giving it multifunctional characteristics.

[0032] Secondly, the swelling agent serves as a good solvent for both the first and second polymer materials. During preparation, the first and second edge portions are swollen separately, allowing them to dissolve. A first pressure is then applied to the interface between the first and second edge portions. In this pressurized liquid environment, the first and second polymer materials in the swelling agent achieve better fusion, with the polymer chains of both materials becoming entangled at the interface, forming an interlocking effect. Simultaneously, the polymer chains in the first and second materials move towards each other, further driving the first and second functional fillers to approach and permeate each other at the interface, thereby reconstructing the interfacial network of the interface. In summary, the interface exhibits good tensile strength, ensuring the reliability of the robust, stretchable strain material under tensile deformation.

[0033] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a method for preparing a robust, tensile strainable material with a robust interface, according to one embodiment.

[0035] Figure 2 This is a scanning electron microscope image of a second composite material in a monodisperse morphology, representing one embodiment.

[0036] Figure 3 A scanning electron microscope image of a first composite material exhibiting an actively aggregated morphology, as shown in one embodiment. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] According to one aspect of the present invention, a method for preparing a tensile strainable material having a robust interface is provided. Please refer to [link / reference needed]. Figure 1 As shown, Figure 1 This is a schematic diagram illustrating a method for preparing a robust, tensile strainable material with a robust interface, according to one embodiment of the present invention.

[0041] The preparation method includes the following steps:

[0042] S1: Provide a first functional filler, a first polymer material, and an agglomeration aid medium; add the first functional filler and the first polymer material to the agglomeration aid medium; and perform a first curing treatment to form a first composite material; the first composite material includes a first base and a first edge portion.

[0043] S2: Provide a second functional filler, a second polymer material, and a dispersion aid medium; add the second functional filler and the second polymer material to the dispersion aid medium; and perform a second curing treatment to form a second composite material; the second composite material includes a second base and a second edge portion.

[0044] S3: Provide a swelling agent, and use the swelling agent to swell the first edge portion and the second edge portion respectively. Under the action of a first pressure, overlap the swollen first edge portion and the second edge portion, and form a connection portion through a third curing treatment to obtain the tensile strain material with a robust interface.

[0045] The functional properties of traditional nanocomposites are mainly determined by the properties of the nanofillers. The functional properties of nanocomposites are typically adjusted by regulating the doping ratio of the nanofillers. This adjustment can alter the overall physical properties of the composite material, such as conductivity, strain sensitivity, humidity sensitivity, Young's modulus, and tensile elongation at break. However, adjusting the doping ratio can only control the functional properties within a limited range and cannot achieve significant adjustments.

[0046] The preparation method of the present invention uses an agglomeration aid medium to enable the first functional filler in the first composite material to be in an active agglomeration state, thereby giving the first composite material high strain sensitivity. Using a dispersion aid medium, the second functional filler in the second composite material can be in a monodisperse state, thereby giving the second composite material high conductivity. The present invention adjusts the dispersion morphology of the first and second functional fillers to achieve a significant adjustment of the functional properties of the tensile strain material with a robust interface, thereby possessing multifunctional characteristics.

[0047] It is understandable that the greater the difference in dispersion morphology between the first functional filler and the second functional filler, the higher the strain sensitivity and conductivity of the resulting tensile strain material with a robust interface will be.

[0048] The active agglomeration state referred to in this article means that the first functional filler in the first composite material forms multiple stable agglomeration clusters under the action of the agglomeration-aiding medium, and these multiple agglomeration clusters are dispersed in the first composite material. This active agglomeration cluster structure is different from the whole agglomeration structure caused by electrostatic adsorption force.

[0049] The swelling agent, acting as a good solvent for both the first and second polymer materials, swells the first and second edges during preparation, allowing them to dissolve. A first pressure is then applied to the interface between the first and second edges. In this pressurized liquid environment, the first and second polymer materials in the swelling agent achieve better fusion, with the polymer chains of both materials becoming entangled and interlocked at the interface. Simultaneously, the polymer chains in the first and second materials move towards each other, further driving the first and second functional fillers closer together and permeating at the interface, thus reconstructing the interfacial network. In summary, the interface exhibits good tensile strength, ensuring the reliability of the robust, strain-resistant material under tensile deformation.

[0050] Preferably, the elongation at break of the tensile strain material with a robust interface is greater than or equal to 100%, and the strain sensitivity coefficient of the tensile strain material with a robust interface is 10-20.

[0051] Typically, the strain sensitivity coefficient is the degree of change in resistance caused by a unit strain, which can be expressed as the ratio of the change in resistance to the degree of strain, where the degree of strain is the proportion of the change in length along the stress loading direction. Preferably, in this embodiment, the strain sensitivity coefficient of the tensile strain-resistant material with a robust interface is 15.

[0052] Specifically, in step S1, the first functional filler includes at least one of silver nanowires, copper nanowires, graphene, and carbon black. The first functional filler exhibits good strain sensitivity in an agglomerated state, and the higher the degree of agglomeration, the better the strain sensitivity, and the more accurate the strain sensitivity of the formed first composite material.

[0053] The first polymeric material includes at least one of styrene-butadiene-styrene block copolymer, polydimethylsiloxane, and copolyester (Ecoflex).

[0054] The agglomeration-promoting medium includes at least one of benzene, toluene, xylene, tetrahydrofuran, chloroform, and dimethyl sulfoxide. These agglomeration-promoting media are poor solvents for the first functional filler and good solvents for the first polymer material. Under the action of the agglomeration-promoting medium, the first functional filler exhibits a relatively stable active agglomeration state.

[0055] Furthermore, if the mass fraction of the first functional filler in the first composite material is too high, it will affect the signal monitoring accuracy, strain sensitivity and tensile properties of the formed first matrix. Therefore, the mass ratio of the first functional filler to the first polymer material is 1:100-55:100.

[0056] Preferably, the mass ratio of the first functional filler to the first polymer material is 1:100-20:100.

[0057] Furthermore, in the step of adding the first functional filler and the first polymer material to the agglomeration medium and forming the first composite material through the first curing treatment, the first dispersion is carried out by a non-invasive homogenizer. In this way, the first functional filler, which is in an active agglomeration state, can be more uniform and stable in the first composite material, and will not undergo deagglomeration or further agglomeration, thereby making the performance of the formed first composite material more stable and reliable.

[0058] Specifically, the first dispersion is preferably a two-stage dispersion: the initial dispersion parameters are 100rpm-500rpm, with 1-2 dispersion cycles, each lasting 5s-15s; 500rpm-1000rpm, with 1-2 dispersion cycles, each lasting 5s-15s; 1000rpm-2500rpm, with 1-2 dispersion cycles, each lasting 10s-30s; and 2500rpm-3600rpm, with 1-2 dispersion cycles, each lasting 10s-30s. The above speeds are revolution speeds, and the rotation speed is 30%-80% of the revolution speed and remains constant. The final dispersion parameters are 1000rpm-2000rpm, with 1-2 dispersion cycles, each lasting 10s-30s; and 2000rpm-3600rpm, with 3-6 dispersion cycles, each lasting 30s-60s. Multi-stage and multiple-stage dispersion can make the aggregated first functional filler more uniformly dispersed in the first polymer material without destroying the aggregated state.

[0059] Furthermore, the first curing process includes casting and heat treatment.

[0060] Furthermore, in step S2, the second functional filler includes at least one of silver nanowires, copper nanowires, graphene, and carbon black; these functional fillers have good conductivity in a monodisperse state, and the higher the degree of monodispersity, the better the conductivity and the smaller the resistance of the second base formed.

[0061] The second polymeric material includes at least one of styrene-butadiene-styrene block copolymer, polydimethylsiloxane, and copolyester (Ecoflex).

[0062] The dispersing medium includes at least one of polyvinylpyrrolidone, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecylamine, Triton, alkyl cellulose, and polyacrylic acid. These dispersing media are good solvents for the second functional filler and for the second polymer material, and the second functional filler exhibits a relatively stable monodisperse state under the action of the dispersing medium.

[0063] Considering that if the mass fraction of the second functional filler in the second composite material is too low, it will affect the electrical conductivity and Young's modulus of the formed second matrix, the mass ratio of the second functional filler to the second polymer material is 5:100-150:100.

[0064] Preferably, the mass ratio of the second functional filler to the second polymer material is 60:100-150:100.

[0065] It is understood that in this embodiment, the mass fraction of the first functional filler in the first composite material and the mass fraction of the second functional filler in the second composite material can be the same, that is, a significant performance adjustment can be achieved with the same filler mass fraction. In other embodiments, the mass fraction of the first functional filler in the first composite material and the mass fraction of the second functional filler in the second composite material can also be adaptively adjusted according to the morphology of the functional filler or the actual use requirements, thus increasing the range of performance adjustment on the original basis.

[0066] Furthermore, in the step of adding the second functional filler and the second polymer material to the dispersion aid to form the second composite material, a second dispersion is performed using a three-roll homogenizer. This makes the monodisperse second functional filler more uniform and stable in the second composite material, preventing micro-agglomeration or localized agglomeration, thereby making the formed second matrix more stable and reliable.

[0067] Specifically, the second dispersion is preferably achieved through a two-stage rolling process: first, the distance between the rollers is adjusted to 10μm-20μm, and the distance between rollers on the same side is adjusted to 5μm-15μm, with the rollers passing through 1-4 times; then, the distance between the rollers is adjusted to 5μm-15μm, and the distance between rollers on the same side is adjusted to 2μm-10μm, with the rollers passing through 1-3 times. By gradually reducing the distance between the rollers, multiple rolling passes can further improve the monodispersity of the second functional filler.

[0068] Furthermore, the second curing process includes casting and heat treatment.

[0069] It is understood that the present invention provides only limited examples of the first and second functional fillers. In addition to the above-mentioned nanofillers with good electrical conductivity, the first and second functional fillers can also be nanofillers with other properties, such as nanofillers with magnetic permeability and thermal permeability. All of these nanofillers can be used to adjust the performance of the tensile strain material with robust interface through the preparation method of the present invention, and are all within the protection scope of the present invention.

[0070] Furthermore, in the preparation method provided by the present invention, the components of the first functional filler and the second functional filler may be the same or different; the components of the first polymer material and the second polymer material may be the same or different.

[0071] In one embodiment, the first functional filler and the second functional filler have the same composition and similar physicochemical properties. Therefore, the first edge portion and the second edge portion will have a low interface impedance at the mixing interface. Specifically, the AC impedance of the connection portion is less than 0.5% of the DC resistance value, and the conductivity ratio of the first base portion to the second base portion is 1:35-1:7000.

[0072] In one embodiment, the first polymer material and the second polymer material have the same composition. Therefore, the first edge portion and the second edge portion will form a good fusion at the mixing interface, resulting in a high interfacial bonding strength for the connecting portion. Specifically, the Young's modulus of the connecting portion is greater than or equal to 100 MPa, preferably greater than or equal to 700 MPa. The ratio of the Young's modulus of the first base portion to the second base portion is 2:1 to 15:1.

[0073] In one embodiment, the first functional filler and the second functional filler have the same composition, and the first polymer material and the second polymer material have the same composition. Therefore, the first edge portion and the second edge portion not only have low interfacial resistance at the mixing interface, but also form good fusion. As a result, the connecting portion will have low interfacial resistance and high Young's modulus.

[0074] Furthermore, in step S3, the first pressure value is 10Pa-1000Pa, and the third curing process includes a drying process, the drying temperature is 20℃-70℃, and the drying time is 0.5h-24h.

[0075] The swelling agent includes at least one of methanol, ethanol, cyclohexane, n-hexane, petroleum ether, benzene, toluene, tetrahydrofuran, chloroform, and dimethyl sulfoxide. These swelling agents are all good solvents for both the first and second polymer materials, enabling the molecular chains of the first and second polymer materials at the connecting portion to swell, and achieving an interlocking structure under the action of a first pressure.

[0076] According to another aspect of the present invention, a robust interface tensile strain material is provided by any of the above-described preparation methods. The robust interface tensile strain material includes a first base, a second base, and a connecting portion, wherein the connecting portion is disposed between the first base and the second base. The elongation at break of the robust interface tensile strain material is greater than or equal to 100%, and the strain sensitivity coefficient is 10-20.

[0077] Preferably, the strain sensitivity coefficient of the tensile strainable material with a robust interface is 15.

[0078] Furthermore, the ratio of the strain sensitivity coefficients of the first matrix to the second matrix in the obtained tensile strain material with a robust interface is 3:1 to 50:1.

[0079] The conductivity ratio of the first base to the second base is 1:35 to 1:7000.

[0080] The ratio of the Young's modulus of the first base to the second base is 2:1 to 15:1.

[0081] When the vibration frequency of the strain signal is 0-1MHz, the AC impedance of the connection is less than 0.5% of the DC resistance.

[0082] The Young's modulus of the connecting part is greater than or equal to 100 MPa, preferably greater than or equal to 700 MPa.

[0083] It is known that by controlling the dispersion state of the functional filler, a huge performance difference can be generated between the first and second bases, thus significantly adjusting the functional properties of the tensile strain material with a robust interface; by adjusting the composition and content of the first and second functional fillers, the interfacial impedance of the joint can be adjusted; by adjusting the composition and content of the first and second polymer materials, the Young's modulus of the joint can be adjusted. In this way, a tensile strain material with a robust interface, possessing multifunctional properties, tensile strength, and low interfacial impedance can be obtained.

[0084] In addition, it should be noted that all the features and advantages described above for the method of preparing a robust interface tensile strain material also apply to this robust interface tensile strain material, and will not be repeated here.

[0085] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the invention in any way. It is worth mentioning that, where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0086] Example 1:

[0087] (1) The silver nanowires were impregnated with toluene solution and then transferred into benzene solution of styrene-butadiene-styrene block copolymer to obtain the first composite material, wherein the mass ratio of silver nanowires to styrene-butadiene-styrene block copolymer was 15:100.

[0088] The first composite material was mixed in a non-invasive homogenizer. The initial mixing parameters were: 500 rpm, 1 dispersion cycle, 15 seconds each; 1000 rpm, 1 dispersion cycle, 15 seconds each; 2000 rpm, 1 dispersion cycle, 15 seconds each; 3000 rpm, 1 dispersion cycle, 15 seconds each, with the rotation speed being 50% of the revolution speed. The final dispersion parameters were: 2000 rpm, 2 dispersion cycles, 30 seconds each; 3200 rpm, 3 dispersion cycles, 30 seconds each. After casting, heating and drying yielded a styrene-butadiene-styrene block copolymer material with silver nanowires in a stable aggregated state.

[0089] (2) The silver nanowires were impregnated with a polyvinylpyrrolidone solution and then transferred into a polyvinylpyrrolidone solution of styrene-butadiene-styrene block copolymer to obtain a second composite material, wherein the mass ratio of silver nanowires to styrene-butadiene-styrene block copolymer was 60:100.

[0090] The second composite material was mixed in a precision three-roll homogenizer. The first rolling parameters were 20 μm between opposite rollers and 10 μm between rollers, and the mixture was rolled once. The second rolling parameters were 10 μm between opposite rollers and 5 μm between rollers, and the mixture was rolled twice. After casting, the mixture was heated and dried to obtain a styrene-butadiene-styrene block copolymer material with silver nanowires in a monodisperse state.

[0091] (3) The edges of the two materials obtained in (1) and (2) are swollen with petroleum ether. After bonding, a pressure of 100 Pa is applied at the interface and the petroleum ether is allowed to evaporate at room temperature for 12 hours. This completes the preparation of a tensile strain material with a robust interface.

[0092] Example 2:

[0093] (1) Copper nanowires are impregnated with dimethyl sulfoxide solution and then transferred into tetrahydrofuran solution of polydimethylsiloxane to obtain the first composite material, wherein the mass ratio of copper nanowires to polydimethylsiloxane is 25:100.

[0094] The first composite material was mixed in a non-invasive homogenizer. The initial mixing parameters were: 100 rpm, 2 dispersions for 10 seconds each; 800 rpm, 2 dispersions for 10 seconds each; 1500 rpm, 1 dispersion for 20 seconds each; and 3200 rpm, 1 dispersion for 20 seconds each. The rotation speed was 60% of the revolution speed. The final dispersion parameters were: 1800 rpm, 1 dispersion for 25 seconds each; and 3000 rpm, 4 dispersions for 40 seconds each. After casting, heating and drying yielded a polydimethylsiloxane material with copper nanowires in a stable aggregated state.

[0095] (2) Copper nanowires were impregnated with tetrahydrofuran solution, and alkyl cellulose was added as a dispersant. Then the mixture was transferred into a tetrahydrofuran solution of polydimethylsiloxane to obtain a second composite material, wherein the mass ratio of copper nanowires to polydimethylsiloxane was 60:100.

[0096] The second composite material was mixed in a precision three-roll homogenizer. The first rolling parameters were 15 μm between opposite rollers and 15 μm between rollers, and the mixture was rolled twice. The second rolling parameters were 15 μm between opposite rollers and 8 μm between rollers, and the mixture was rolled once. After casting, heating and drying yielded a polydimethylsiloxane material with copper nanowires in a monodisperse state.

[0097] (3) The edges of the two materials obtained in (1) and (2) are swollen with toluene. After bonding, a pressure of 1000 Pa is applied at the interface, and the toluene is evaporated at 70 °C for 0.5 h. The preparation of the tensile strain material with robust interface is thus completed.

[0098] Example 3:

[0099] (1) Carbon black is impregnated with a chloroform and dimethyl sulfoxide solution and then transferred into a chloroform and dimethyl sulfoxide solution of polydimethylsiloxane to obtain a first composite material, wherein the mass ratio of carbon black to polydimethylsiloxane is 5:100.

[0100] The first composite material was mixed in a non-invasive homogenizer. The initial mixing parameters were: 500 rpm, 1 dispersion cycle, 15 seconds each; 500 rpm, 2 dispersion cycles, 15 seconds each; 1000 rpm, 2 dispersion cycles, 30 seconds each; 2500 rpm, 2 dispersion cycles, 30 seconds each, with the rotation speed being 80% of the revolution speed. The final dispersion parameters were: 1000 rpm, 2 dispersion cycles, 30 seconds each; 2000 rpm, 6 dispersion cycles, 60 seconds each. After casting, heating and drying yielded a polydimethylsiloxane material with carbon black in a stable agglomerated state.

[0101] (2) The carbon black is impregnated with an alkyl cellulose and polyacrylic acid solution, and then transferred into an alkyl cellulose and Triton solution of polydimethylsiloxane to obtain a second composite material, wherein the mass ratio of carbon black to polydimethylsiloxane is 25:100.

[0102] The second composite material was mixed in a precision three-roll homogenizer. The parameters for the first roll pass were 10 μm between the rollers and 5 μm between the rollers, and the mixture was passed through the rollers four times. The parameters for the second roll pass were 5 μm between the rollers and 10 μm between the rollers, and the mixture was passed through the rollers once. After casting, the mixture was heated and dried to obtain polydimethylsiloxane material with carbon black in a monodisperse state.

[0103] (3) The edges of the two materials obtained in (1) and (2) are swollen with chloroform. After bonding, a pressure of 800 Pa is applied at the interface, and the chloroform is evaporated at 40°C for 24 h. This completes the preparation of a tensile strain material with a robust interface.

[0104] Example 4:

[0105] This embodiment is basically the same as Embodiment 1, except that the second functional filler in the second composite material is graphene.

[0106] Example 5:

[0107] This embodiment is basically the same as Embodiment 1, except that the second polymer material in the second composite material is polydimethylsiloxane.

[0108] Comparative Example 1:

[0109] This embodiment is basically the same as Embodiment 1, except that: the first composite material does not use a coagulating agent, and the mixed solvent is ethanol.

[0110] Comparative Example 2:

[0111] This embodiment is basically the same as Embodiment 1, except that the first composite material is not mixed using a non-invasive homogenizer.

[0112] Comparative Example 3:

[0113] This embodiment is basically the same as Embodiment 1, except that the first pressure is 1 Pa.

[0114] The elongation at break, strain sensitivity coefficient, and conductivity of the robust interface-based tensile strain materials prepared in Examples 1-5 and Comparative Examples 1-3 were tested. The test results show that the tensile strain materials prepared in Examples 1-5 of this invention have high elongation at break, high conductivity, and strain sensitivity, while the joint has low interfacial impedance and high Young's modulus. However, in Comparative Example 1, the first composite material did not use a coagulant, resulting in poor strain sensitivity of the tensile strain material, which in turn led to poor accuracy of signal detection. In Comparative Example 2, the first composite material was not mixed using a non-invasive homogenizer, resulting in uneven distribution of the first functional filler in an actively agglomerated form, leading to significant differences in the agglomeration morphology of the first functional filler, which also resulted in poor strain sensitivity of the tensile strain material, which in turn led to poor accuracy of signal detection. In Comparative Example 3, the first pressure value was too small, resulting in a low elongation at break of the joint and easy breakage.

[0115] The first and second composite materials with robust interfaces of the tensile strain material prepared in Example 2 were subjected to SEM scanning. The second functional filler in the second composite material was monodisperse, such as... Figure 2 As shown. The first functional filler in the first composite material is in an actively agglomerated state, such as... Figure 3 As shown.

[0116] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0117] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method of making a stretchable strain material with a robust interface, characterized in that, The method comprises the following steps: providing a first functional filler, a first high polymer material and an auxiliary agglomeration medium, adding the first functional filler and the first high polymer material into the auxiliary agglomeration medium, and forming a first composite material through a first solidification treatment, the first composite material comprising a first base and a first rim, wherein the auxiliary agglomeration medium comprises at least one of benzene, toluene, xylene, tetrahydrofuran, chloroform, dimethyl sulfoxide, and the first solidification treatment comprises casting forming and heating treatment, and the step of adding the first functional filler and the first high polymer material into the auxiliary agglomeration medium to form the first composite material is performed by a non-intrusive homogenizer for first dispersion; providing a second functional filler, a second high polymer material and an auxiliary dispersion medium, adding the second functional filler and the second high polymer material into the auxiliary dispersion medium, and forming a second composite material through a second solidification treatment, the second composite material comprising a second base and a second rim, wherein the auxiliary dispersion medium comprises at least one of polyvinylpyrrolidone, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, hexadecylamine, triton, alkyl cellulose, and polyacrylic acid, and the second solidification treatment comprises casting forming and heating treatment; providing a swelling agent, swelling the first rim and the second rim by the swelling agent respectively, and forming a connecting part through a third solidification treatment under the action of a first pressure, to obtain the stretchable strain material with a robust interface, wherein the swelling agent comprises at least one of methanol, ethanol, cyclohexane, n-hexane, petroleum ether, benzene, toluene, tetrahydrofuran, chloroform, and dimethyl sulfoxide, and the third solidification treatment comprises drying treatment.

2. The method of claim 1, wherein the method further comprises: The stretchable strain material with a robust interface has an elongation at break greater than or equal to 100%, and a strain sensitivity coefficient of 10-20.

3. The method of claim 1, wherein the method further comprises: The first high polymer material and the second high polymer material have the same composition, and the tensile strength of the connecting part is greater than that of the first high polymer material and the second high polymer material, and the ratio of the Young's modulus of the first base to the second base is 2:1-15:

1. And / or, the first functional filler and the second functional filler have the same composition, and the AC impedance of the connecting part is less than 0.5% of the DC resistance value when the vibration frequency of the strain signal is 0-1 MHz, and the ratio of the electrical conductivity of the first base to the second base is 1:35-1:7000.

4. The method of claim 1, wherein the stretchable strain material having a robust interface is prepared by, The first functional filler comprises at least one of silver nanowires, copper nanowires, graphene and carbon black. And / or, the second functional filler comprises at least one of silver nanowires, copper nanowires, graphene and carbon black. And / or, the first high polymer material comprises at least one of styrene-butadiene-styrene block copolymer, polydimethylsiloxane and copolyester. And / or, the second high polymer material comprises at least one of styrene-butadiene-styrene block copolymer, polydimethylsiloxane and copolyester.

5. The method of claim 1, wherein the stretchable strain material having a robust interface is prepared by, The mass ratio of the first functional filler to the first polymer material is 1:100-55:

100. And / or, the mass ratio of the second functional filler to the second polymer material is 5:100-150:

100.

6. The method of claim 1, wherein the stretchable strain material having a robust interface is prepared by, The second dispersion is performed by a three-roll homogenizer in the step of adding the second functional filler and the second polymer material into the auxiliary dispersion medium to form a second composite material.

7. The method of claim 1, wherein the stretchable strain material having a robust interface is prepared by, The first pressure value is 10 Pa-1000 Pa. And / or, the third solidification treatment comprises a drying treatment, the temperature of the drying treatment is 20℃-70℃, and the time of the drying treatment is 0.5h-24h.

8. A stretchable strain material having robust interfaces, as obtained by the method of any one of claims 1-7, characterized in that, The stretchable strain material with robust interface comprises a first base, a second base, and a connecting part, the connecting part is arranged between the first base and the second base.

9. The stretchable strain material with robust interface of claim 8, wherein, The breaking elongation of the stretchable strain material with robust interface is greater than or equal to 100%, and the strain sensitivity coefficient of the stretchable strain material with robust interface is 10-20. And / or, the ratio of the strain sensitivity coefficients of the first base and the second base is 3:1-50:

1. And / or, the ratio of the electrical conductivities of the first base and the second base is 1:35-1:7000. And / or, the ratio of the Young's moduli of the first base and the second base is 2:1-15:1.

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