Integrated strain sensing insole and method of manufacturing the same

Abstract

The application belongs to the technical field of intelligent medical treatment, and specifically discloses an integrated strain sensing insole and a preparation method thereof. The preparation method comprises the following steps: immersing an elastomer prepolymer into a porous base material and performing solidification; patterning the porous base material embedded with the elastomer and fixing the porous base material in an insole mold, injecting the elastomer prepolymer, and performing solidification; taking out the insole from the insole mold and dissolving the porous base material in the insole, so as to obtain an insole embedded with a foamed elastomer; attaching a conductive material to the inside of the foamed elastomer and attaching electrodes to the upper and lower surfaces, so as to obtain the integrated strain sensing insole. The insole has good wearing comfort, good long-term working cycle stability, good plantar stress recognition capability, and long-term stability far superior to that of an assembled pressure insole and other types of insoles, and can accurately monitor the plantar pressure distribution and change process in different standing postures and different motion states.

Description

Technical Field

[0001] This invention discloses an integrated strain-sensing insole and its preparation method, belonging to the field of smart medical technology. Background Technology

[0002] Wearable electronic systems have shown potential applications in disease prevention and health monitoring. Continuous monitoring of plantar pressure and its changes is of great value for the diagnosis and prevention of foot diseases, as well as for assessing stress on the lower limbs and lumbar structures and correcting movement postures.

[0003] Most existing technologies involve attaching pressure sensors to the surface of insoles to collect foot pressure and gait data. However, existing sensors lack flexibility; under continuous pressure and bending, they are prone to damage or detachment from the insole, leading to sensing failure. Consequently, they suffer from poor stability, low integration, and strong invasiveness to the foot, making it impossible for foot pressure sensors to accurately diagnose and prevent diseases and movement conditions. Summary of the Invention

[0004] The purpose of this application is to provide an integrated strain-sensing insole and its manufacturing method, so as to solve the technical problems of existing foot pressure sensors, such as poor flexibility, poor stability, low degree of integration, and strong foot invasiveness, which make it impossible to make accurate diagnosis and prevention of diseases and exercise status.

[0005] The first aspect of the present invention provides a method for preparing an integrated strain-sensing insole, comprising:

[0006] The elastomer prepolymer is impregnated into a porous substrate and then cured.

[0007] The porous substrate with embedded elastomer is patterned and fixed in the insole mold, the elastomer prepolymer is injected and cured;

[0008] The insole is removed from the insole mold and its porous substrate is dissolved to obtain an insole embedded with a foam-like elastomer;

[0009] Conductive material is uniformly attached inside a foam-like elastomer, and electrodes are attached to the upper and lower surfaces to obtain an integrated strain-sensing insole.

[0010] Preferably, the elastomer prepolymer is impregnated into a porous substrate and then cured, specifically including:

[0011] Prepare an elastomer prepolymer solution;

[0012] The porous substrate is placed in the solution, and after the porous substrate is fully immersed in the solution, it is cured.

[0013] The porous substrate is a material that is easily soluble.

[0014] Preferably, the elastomer prepolymer is at least one of PDMS, Ecoflex, polyethylene, and polyurethane.

[0015] Preferably, when the elastomer prepolymer is PDMS, the mass ratio of the PDMS stock solution to the curing agent used is 5:1 to 20:1.

[0016] Preferably, the substrate is a sugar cube, a block of salt, or a foamed metal.

[0017] Preferably, the substrate with embedded elastomer is patterned and fixed in the insole mold, the elastomer prepolymer is injected, and then cured, specifically including:

[0018] Prepare an insole mold with multiple fixing holes;

[0019] Based on the number and size of the fixing holes in the insole mold, the porous substrate with embedded elastomer is cut to obtain a patterned substrate;

[0020] Each of the patterned substrates is embedded in the fixing hole;

[0021] An elastomer prepolymer solution is injected into an insole mold to which the patterned substrate is fixed, so that the current elastomer prepolymer solution cross-links and cures with the already cured elastomer in the porous substrate.

[0022] Preferably, the material of the insole mold is a polymer or stainless steel, specifically including at least one of PMMA (polymethyl methacrylate, commonly known as acrylic), PET (polyethylene terephthalate), HDPE (high-density polyethylene), LDPE (low-density polyethylene), PS (polystyrene), polyimide (PAI), polyamide (PA), thermoplastic polyamide (TPI), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and acrylonitrile-butadiene-styrene copolymer (ABS).

[0023] Preferably, the insole is removed from the insole mold and the porous substrate therein is dissolved to obtain an insole embedded with a foam-like elastomer, specifically including:

[0024] Remove the insoles from the insole mold;

[0025] The removed insole is placed in a solvent such as water, alcohol, acetone or hydrochloric acid to dissolve the substrate, resulting in an insole embedded with a foam-like elastomer.

[0026] Preferably, a conductive material is uniformly attached inside the foam-like elastomer and electrodes are attached to the upper and lower surfaces to obtain an integrated strain-sensing insole, specifically including:

[0027] Preparation of conductive material dispersions;

[0028] The insole embedded with foam elastomer is immersed in the conductive material dispersion and subjected to ultrasonic treatment so that the conductive material is uniformly attached inside each foam elastomer.

[0029] Electrodes are attached to the upper and lower surfaces of each foam-like elastomer coated with conductive material to obtain an integrated strain-sensing insole.

[0030] A second aspect of the present invention provides an integrated strain-sensing insole prepared using the above-described preparation method.

[0031] The integrated strain-sensing insole and its preparation method of the present invention have the following advantages compared with the prior art:

[0032] This invention relates to an integrated strain-sensing insole, which offers excellent comfort due to its flexibility, high degree of integration, and minimal invasiveness to the foot. It also exhibits good long-term operational cycle stability and superior plantar pressure recognition capabilities, demonstrating significantly better long-term stability than assembled pressure insoles and other types of insoles. It can be applied to plantar pressure monitoring, accurately monitoring the distribution and changes in plantar pressure under different standing postures and movement states. This makes it suitable for the diagnosis and prevention of foot, lower limb, and lumbar diseases, as well as for posture correction during exercise. Attached Figure Description

[0033] Figure 1 This is a flowchart of the preparation method of the integrated strain-sensing insole of the present invention;

[0034] Figure 2 This is an exploded view of the integrated strain-sensing insole of the present invention.

[0035] Figure 3 These are SEM images of a single flexible foam resistive strain sensor in the integrated strain sensing insole obtained in Embodiment 5 of the present invention at different magnifications, wherein (a) is a scan image at 100 μm; and (b) is a scan image at 500 μm.

[0036] Figure 4 The resistance response curves of a single flexible foam resistive strain sensor in the integrated strain sensing insole obtained in Embodiment 5 of the present invention at different frequencies are shown.

[0037] Figure 5 The image shows the long-term cyclic stability curve of a single flexible foam resistive strain sensor in the integrated strain sensing insole obtained in Embodiment 5 of the present invention.

[0038] In the diagram, 1 is a foam-shaped sensing electrode; 2 is a shoe insole; and 3 is an electrode. Detailed Implementation

[0039] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0040] The first aspect of the present invention provides a method for preparing an integrated strain-sensing insole, such as... Figure 1 and Figure 2 As shown, it includes:

[0041] Step 1: Impregnate the elastomer prepolymer into a porous substrate and cure it, specifically including:

[0042] Step 1.1: Prepare the elastomer prepolymer solution.

[0043] In this embodiment of the invention, the elastomer prepolymer is at least one of PDMS, Ecoflex, polyethylene, and polyurethane.

[0044] For example, when the elastomer prepolymer is PDMS, the mass ratio of the PDMS stock solution to the curing agent used is from 5:1 to 20:1, for example, it can be 5:1, 8:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 20:1, etc., preferably 15:1.

[0045] For example, when the elastomer prepolymer is PDMS, the original solution of the elastomer prepolymer is Dow Corning SYGARD184 silicone rubber.

[0046] In this embodiment of the invention, the PDMS stock solution and the curing agent are mixed evenly to obtain an elastomer prepolymer solution.

[0047] Step 1.2: Place the porous substrate in the elastomer prepolymer solution. After the porous substrate is fully immersed in the solution, cure it. The substrate is a porous material that is easily dissolved and removed.

[0048] The substrate used in the embodiments of the present invention can be a sugar cube, a block of salt, or a foamed metal. Since the porosity of a sugar cube is more uniform, it is preferred to use a sugar cube as the substrate in the embodiments of the present invention.

[0049] For example, step 1.2 specifically involves: placing the sugar cube in the elastomer prepolymer solution prepared in step 1.1, and then placing it in a vacuum chamber for vacuum extraction and maintaining this position for a certain period of time. This allows the elastomer prepolymer solution to completely penetrate the naturally formed void structure of the sugar cube under pressure. The sugar cube completely immersed in the elastomer prepolymer solution is then cured at 50-60°C. The purpose of vacuum extraction is to allow the elastomer prepolymer solution to fully penetrate the microstructure of the sugar cube and to expel internal air.

[0050] Step 2: Pattern the substrate with embedded elastomer and fix it in the insole mold, inject the elastomer prepolymer, and cure it;

[0051] Step 2 of this embodiment of the invention specifically includes:

[0052] Step 2.1: Prepare an insole mold with multiple fixing holes.

[0053] For example, a shoe insole mold with pre-arrayed perforations is tightly bonded to a shoe insole mold with a central perforated shoe insole pattern to form a complete shoe insole mold. The shoe insole mold can be made of polymer or stainless steel, specifically at least one of PMMA (polymethyl methacrylate, commonly known as acrylic), PET (polyethylene terephthalate), HDPE (high-density polyethylene), LDPE (low-density polyethylene), PS (polystyrene), polyimide (PAI), polyamide (PA), thermoplastic polyamide (TPI), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and acrylonitrile-butadiene-styrene copolymer (ABS). The number of perforations on the shoe insole mold can be 2-50, and the size can range from 0.1cm*0.1cm to 3cm*3cm.

[0054] Step 2.2: Cut the substrate with embedded elastomer according to the number and size of the fixing holes in the insole mold to obtain a patterned substrate;

[0055] Step 2.3: Embed each patterned substrate into the fixing hole. The number of patterned substrates can be 2-50, and the size can range from 0.1cm*0.1cm*0.1cm to 3cm*3cm*3cm. Their number and size are the same as the number and size of the holes in the insole mold.

[0056] Step 2.4: Pour an elastomer prepolymer solution into the insole mold with a fixed patterned substrate, so that the current elastomer prepolymer solution cross-links and cures with the elastomer already cured in the porous substrate.

[0057] The elastomer prepolymer solution used in this step may have the same or different composition as the solution used to fill the porous substrate.

[0058] Step 3: Remove the insole from the insole mold and dissolve the porous substrate therein to obtain insole 2 with embedded foam elastomer;

[0059] Step 3 of this embodiment of the invention specifically includes:

[0060] Step 3.1: Remove the insole mold and take out the insole from the insole mold.

[0061] Step 3.2: Place the removed insole in a solvent to dissolve the substrate, resulting in an insole embedded with a foam-like elastomer.

[0062] The solvent used in the embodiments of the present invention can be water, alcohol, acetone, or hydrochloric acid, etc. For example, the removed insole is immersed in deionized water until the porous substrate is completely dissolved, thus obtaining an insole embedded with a foam-like elastomer.

[0063] Step 4: Uniformly attach conductive material inside the foam elastomer and attach electrodes to the upper and lower surfaces to obtain an integrated strain-sensing insole, specifically including:

[0064] Step 4.1: Prepare a conductive material dispersion.

[0065] For example, the conductive material is ultrasonically dispersed in an ethanol solution for 10-60 minutes to obtain an ethanol dispersion of the conductive material, wherein the concentration of the dispersion is from 0.1 mg / ml to 100 mg / ml.

[0066] The conductive material in the embodiments of the present invention may be at least one of carbon nanotubes, acetylene black, graphene, MXene, silver nanowires, and copper nanowires.

[0067] Step 4.2: Immerse the insole embedded with foam elastomer into a conductive material dispersion and perform ultrasonic treatment to ensure that the conductive material is uniformly attached inside each foam elastomer, thus obtaining the foam sensing electrode 1.

[0068] In this embodiment of the invention, the purpose of ultrasonic treatment is to allow the conductive material to adhere uniformly to the inner wall of the foam elastomer, thereby forming a flexible foam resistive strain sensor with excellent performance.

[0069] Step 4.3: Attach electrode 3 to the upper and lower surfaces of each foam elastomer with conductive material to obtain an integrated strain-sensing insole.

[0070] A second aspect of the present invention provides an integrated strain-sensing insole prepared using the above-described preparation method.

[0071] The integrated strain-sensing insole prepared using the above method has excellent wearing comfort, good long-term working cycle stability, and good plantar pressure recognition capability. It has a long-term stability performance that is far superior to assembled pressure insoles and other types of insoles. It can be applied to plantar pressure monitoring to accurately monitor the distribution and changes of plantar pressure under different standing postures and different exercise states. It is suitable for the diagnosis and prevention of foot, lower limb and waist diseases, as well as exercise posture correction.

[0072] The preparation method of the present invention will be described in detail below with more specific embodiments.

[0073] Example 1

[0074] a. Immerse the block salt in the elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 15:1) and completely impregnate it under a negative pressure vacuum of 10 Pa for 3 hours;

[0075] b. Place the block salt completely impregnated with the elastomer prepolymer solution in a 60°C oven for 3 hours to allow it to fully cure, thus obtaining the filled substrate;

[0076] c. Cut the fully impregnated and cured filled substrate into 22 cuboids of a certain size (0.3cm*0.3cm*0.8cm) and embed them in an array into a pre-drilled polymethyl methacrylate insole mold. Then, fully fill the insole-shaped mold containing the 22 filled foam elastomers with an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 10:1) and cure it at 70°C for 2 hours until it is completely cured. Then, remove the insole mold and immerse the insole in deionized water for 2 hours to completely dissolve the blocky salt, thus obtaining an insole containing 22 foam elastomers.

[0077] d. Carbon nanotubes and acetylene black were ultrasonically dispersed in an ethanol solution for 40 min, with a mass ratio of carbon nanotubes to acetylene black of 1:1, to obtain a carbon nanotube / acetylene black ethanol dispersion with a concentration of 10 mg / ml. The insole containing the above-mentioned 22-channel foam elastomer was immersed in the dispersion and ultrasonically treated to ensure that the carbon nanotubes and acetylene black nanoparticles were completely immersed in the pores of the foam elastomer, forming conductive pathways.

[0078] e. Finally, dry the insole containing 22-channel foam elastomer to remove the ethanol from the foam elastomer, attach copper / polyethylene terephthalate electrodes to the upper and lower sides of the foam elastomer, and connect them externally with copper wire.

[0079] Using block salt as a skeletal template, the flexible porous skeletal foam structure in the prepared one-piece insole is relatively loose. The resulting one-piece insole exhibits an average decrease of 18% in multi-channel resistance after 5000 pressing cycles.

[0080] Example 2

[0081] a. Immerse the sugar cube in an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 10:1) and completely impregnate it under a negative pressure vacuum of 12 Pa for 2 hours;

[0082] b. Place the sugar cube, which is completely impregnated with the elastomer prepolymer solution, in a 50°C oven for 4 hours to allow it to fully solidify, thus obtaining the filled substrate;

[0083] c. Cut the fully impregnated and cured sugar cube substrate into 22 cuboids of a certain size (0.3cm*0.3cm*0.8cm) and embed them in an array into a pre-drilled polymethyl methacrylate insole mold. Then, fully fill the insole-shaped mold containing the 22 filled foam elastomers with an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 10:1) and cure it at 65°C for 3 hours until it is completely cured. Then, remove the insole mold and immerse the insole in deionized water for 3 hours to completely dissolve the sugar cubes, thus obtaining an insole containing 22 foam elastomers.

[0084] d. Carbon nanotubes and acetylene black were ultrasonically dispersed in an ethanol solution for 40 min, with a mass ratio of carbon nanotubes to acetylene black of 2:1, to obtain a carbon nanotube / acetylene black ethanol dispersion with a concentration of 15 mg / ml. The insole containing the above-mentioned 22-channel foam elastomer was immersed in the dispersion and ultrasonically treated to ensure that the carbon nanotubes and acetylene black nanoparticles were completely immersed in the pores of the foam elastomer structure, forming conductive pathways.

[0085] e. Finally, dry the insole containing 22-channel foam elastomer to remove the ethanol from the foam elastomer, attach copper / polyethylene terephthalate electrodes to the upper and lower sides of the foam elastomer, and connect them externally with copper wire.

[0086] Using sugar cubes as a scaffold template, the integrated insole prepared with a PDMS stock solution to curing agent ratio of 10:1 has a high modulus and can accurately identify the stress signal corresponding to large stress deformation, but cannot accurately identify the stress signal of small stress (<0.2Pa) that increases or decreases under large stress deformation.

[0087] Example 3

[0088] a. Immerse the sugar cube in an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 15:1) and completely impregnate it under a negative pressure vacuum of 15 Pa for 2.5 h;

[0089] b. Place the sugar cubes, which are completely impregnated with the elastomer prepolymer solution, in a 55°C oven for 3.5 hours to allow them to fully cure, thus obtaining the filled substrate;

[0090] c. Cut the fully impregnated and cured sugar cube substrate into 22 cuboids of a certain size (0.3cm*0.3cm*0.8cm) and embed them in an array into a pre-drilled polymethyl methacrylate (PMMA) insole mold. Then, fully fill the insole-shaped mold containing the 22 filled foam elastomers with an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 10:1) and cure it at 70°C for 2.5 hours until fully cured. After that, remove the insole mold and immerse the insole in deionized water for 2 hours to completely dissolve the sugar cubes, thus obtaining an insole containing 22 foam elastomers.

[0091] d. Carbon nanotubes were ultrasonically dispersed in an ethanol solution for 40 min to obtain a carbon nanotube / ethanol dispersion with a concentration of 15 mg / ml. The insole containing the above-mentioned 22-channel foam elastomer was immersed in the dispersion and ultrasonically treated to completely immerse the carbon nanotube nanoparticles into the pores of the foam elastomer structure, forming conductive pathways.

[0092] e. Finally, dry the insole containing 22-channel foam elastomer to remove the ethanol from the foam elastomer, attach copper / polyethylene terephthalate electrodes to the upper and lower sides of the foam elastomer, and connect them externally with copper wire.

[0093] The stability of the integrated insole prepared by using sugar cubes as the skeleton template and carbon nanotubes as the conductive filler at the pixel foam is worse than that of the integrated insole prepared by using a combination of carbon nanotubes and acetylene black as the conductive filler. Under 5000 cycles, the average resistance of the multi-channel pixels decreased by 5%. This is because carbon nanotubes have a negative resistance effect to temperature. As the pixel foam is compressed and deformed in the closed space for a long time, the temperature of the insole increases, which interferes with the basic resistance and sensitivity of the sensor.

[0094] Example 4

[0095] a. Immerse the sugar cube in an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 15:1) and completely impregnate it under a negative pressure vacuum of 10 Pa for 3 hours;

[0096] b. Place the sugar cube, which is completely impregnated with the elastomer prepolymer solution, in a 60°C oven for 3 hours to allow it to fully solidify, thus obtaining the filled substrate;

[0097] c. Cut the fully impregnated and cured filled substrate into 22 cuboids of a certain size (0.3cm*0.3cm*0.8cm) and embed them in an array into a pre-drilled polymethyl methacrylate insole mold. Then, fully fill the insole-shaped mold containing the 22 filled foam elastomers with an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 15:1) and cure it at 68°C for 2.5 hours until it is completely cured. Then, remove the insole mold and immerse the insole in deionized water for 2 hours to completely dissolve the sugar cubes, thus obtaining an insole containing 22 foam elastomers.

[0098] d. Carbon nanotubes and acetylene black were ultrasonically dispersed in an ethanol solution for 40 min, with a mass ratio of carbon nanotubes to acetylene black of 1:1, to obtain a carbon nanotube / acetylene black ethanol dispersion with a concentration of 20 mg / ml. The insole containing the above-mentioned 22-channel foam elastomer was immersed in the dispersion and ultrasonically treated to ensure that the carbon nanotubes and acetylene black nanoparticles were completely immersed in the pores of the foam elastomer structure, forming conductive pathways.

[0099] e. Finally, dry the insole containing 22-channel foam elastomer to remove the ethanol from the foam elastomer, attach copper / polyethylene terephthalate electrodes to the upper and lower sides of the foam elastomer, and connect them externally with copper wire.

[0100] Using sugar cubes as a scaffold template, the integrated insole prepared with a PDMS stock solution to curing agent ratio of 15:1 has a low modulus and a weakened ability to identify large strains. In addition, the insole exhibits resistance signal drift after 3 hours of dynamic operation. This is because the external electrode and the overall modulus of the insole are mismatched, and a reliable physical connection cannot be formed during long-cycle dynamic operation.

[0101] Example 5

[0102] a. Immerse the sugar cube in an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 15:1) and completely impregnate it under a negative pressure vacuum of 10 Pa for 3 hours;

[0103] b. Place the sugar cube, which is completely impregnated with the elastomer prepolymer solution, in a 60°C oven for 3 hours to allow it to fully solidify, thus obtaining the filled substrate;

[0104] c. Cut the fully impregnated and cured sugar cube substrate into 22 cuboids of a certain size (0.3cm*0.3cm*0.8cm) and embed them in an array into a pre-perforated polymethyl methacrylate insole mold. Then, the insole mold containing the 22 filled foam elastomers is fully filled with an elastomer prepolymer solution (PDMS stock solution: curing agent ratio of 10:1) and cured at 80°C for 2 hours until fully cured. Then, the insole mold is removed and the insole is immersed in deionized water for 2 hours to completely dissolve the sugar cubes, thus obtaining an insole containing 22 foam elastomers.

[0105] d. Carbon nanotubes and acetylene black were ultrasonically dispersed in an ethanol solution for 40 min, with a mass ratio of carbon nanotubes to acetylene black of 1:1, to obtain a carbon nanotube / acetylene black ethanol dispersion with a concentration of 50 mg / ml. The aforementioned integrated prefabricated insole containing 22 channels of foam elastomer was immersed in this dispersion and ultrasonically treated to ensure that the carbon nanotubes and acetylene black nanoparticles were completely immersed in the pores of the foam elastomer structure, forming conductive pathways.

[0106] e. Finally, dry the insole containing 22-channel foam elastomer to remove the ethanol from the foam elastomer, attach copper / polyethylene terephthalate electrodes to the upper and lower sides of the foam elastomer, and connect them externally with copper wire.

[0107] Using sugar cubes as the skeletal template, with a PDMS stock solution to curing agent ratio of 15:1 in the porous areas and 10:1 in the insole body, and CNT / ACET as the conductive filler at the pixel foam, the integrated insole exhibits reliable modulus. The modulus is slightly lower in the porous areas, resulting in strong dynamic stress recognition capabilities at the porous areas. No significant difference in signal recognition and extraction was observed during long-term wear (30 days). Furthermore, the integrated insole of this invention demonstrates good stability; after 10,000 long cycles, the resistance of a single pixel sensor showed no significant decline (<1%). Figures 3 to 5 .

[0108] This invention designs an integrated insole incorporating multiple foam-like resistive strain sensors, which significantly improves the stability of foot pressure sensing signals, thereby enhancing the accuracy of diagnosis and prevention of foot, lower limb, and lumbar diseases. It can also be applied to posture correction during exercise. This integrated insole can accurately monitor the distribution and changes in plantar pressure under different exercise conditions. This invention significantly improves the accuracy and stability of sensing signals through a rational structural design of the sensing elements and the adoption of an integrated assembly strategy.

[0109] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing an integrated strain-sensing insole, characterized in that, include: The elastomer prepolymer is impregnated into a porous substrate and then cured. The porous substrate with embedded elastomer is patterned and fixed in the insole mold, the elastomer prepolymer is injected and cured; The insole is removed from the insole mold and its porous substrate is dissolved to obtain an insole embedded with a foam-like elastomer; By attaching conductive material inside a foam-like elastomer and attaching electrodes to the upper and lower surfaces, an integrated strain-sensing insole is obtained.

2. The method of claim 1, wherein the one-piece strain sensing insole is prepared by the steps of: The process involves impregnating an elastomer prepolymer into a porous substrate and then curing it, specifically including: ​ Prepare an elastomer prepolymer solution; The porous substrate is placed in the solution, and after the porous substrate is fully immersed in the solution, it is cured. The porous substrate is a material that is easily soluble.

3. The method for preparing the integrated strain-sensing insole according to claim 2, characterized in that, The elastomer prepolymer is at least one of PDMS, Ecoflex, polyethylene, and polyurethane.

4. The method for preparing the integrated strain-sensing insole according to claim 3, characterized in that, When the elastomer prepolymer is PDMS, the mass ratio of the PDMS stock solution to the curing agent used is 5:1 to 20:

1.

5. The method for preparing the integrated strain-sensing insole according to claim 1, characterized in that, The porous substrate is a sugar cube, a block of salt, or a foamed metal.

6. The method for preparing the integrated strain-sensing insole according to claim 1, characterized in that, The substrate with embedded elastomer is patterned and fixed in an insole mold, then the elastomer prepolymer is injected and cured. Specifically, this includes: Prepare an insole mold with multiple fixing holes; Based on the number and size of the fixing holes in the insole mold, the porous substrate with embedded elastomer is cut to obtain a patterned substrate; Each of the patterned substrates is embedded in the fixing hole; An elastomer prepolymer solution is injected into an insole mold to which the patterned substrate is fixed, so that the current elastomer prepolymer solution cross-links and cures with the already cured elastomer in the porous substrate.

7. The method for preparing the integrated strain-sensing insole according to claim 6, characterized in that, The material of the insole mold is at least one of high molecular polymer and stainless steel.

8. The method for preparing the integrated strain-sensing insole according to claim 1, characterized in that, The insole is removed from the insole mold, and the porous substrate within it is dissolved to obtain an insole embedded with a foam-like elastomer, specifically including: Remove the insoles from the insole mold; The removed insole is placed in a solvent to dissolve the porous substrate, resulting in an insole embedded with a foam-like elastomer.

9. The method for preparing the integrated strain-sensing insole according to claim 1, characterized in that, By attaching conductive material inside a foam-like elastomer and attaching electrodes to its upper and lower surfaces, an integrated strain-sensing insole is obtained, specifically comprising: Preparation of conductive material dispersions; The insole embedded with foam elastomer is immersed in the conductive material dispersion and subjected to ultrasonic treatment so that the conductive material is uniformly attached inside each foam elastomer. Electrodes are attached to the upper and lower surfaces of each foam-like elastomer coated with conductive material to obtain an integrated strain-sensing insole.

10. An integrated strain sensing insole, characterized by, The integrated strain-sensing insole is prepared using the method described in any one of claims 1-9.

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