A novel porous breathable sandwich structure intelligent bandage with electromagnetic shielding, electric heating, impact resistance and sensing performance

Abstract

The application discloses a novel porous breathable sandwich structure intelligent bandage with electromagnetic shielding, electric heating, impact resistance and sensing performance, which is a sandwich structure and comprises a conductive non-woven fabric layer as an intermediate interlayer and porous polyborosiloxane elastomers arranged on both sides of the conductive non-woven fabric layer. The intelligent bandage integrates electromagnetic shielding, electric heating, impact resistance and sensing performance, can be widely applied to human health monitoring, sports protection and personal medical care fields, can realize monitoring of electric signals generated by human activities, has electric heating performance and can relieve muscle tension through hot compress, and meanwhile, the electromagnetic shielding and impact resistance performance can provide multiple protection for the human body.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of human health monitoring and sports protection, and particularly relates to a novel porous breathable sandwich structure intelligent bandage with electromagnetic shielding, electric heating, impact resistance and sensing performance. BACKGROUND

[0002] Sports bandages are used to prevent sports injuries and protect joints and muscles, and play a crucial role in daily life. With the development of flexible wearable intelligent bandages, intelligent bandages with sports monitoring function can measure the electrical signals generated by human activities, including joint movement monitoring, body temperature measurement, etc., and can provide new opportunities for human activity monitoring, sports protection and personal health care.

[0003] Intelligent bandages with high sensitivity, wide range, fast response and recovery time have been intensively developed and widely used to monitor physiological signals such as heart rate, respiratory activity and muscle tension. Intelligent bandages that can accurately and real-time detect body movement signals have sprung up like mushrooms. The patent with publication number CN215534394U discloses a lumbar joint activity monitoring device, which includes a controller, two longitudinal patches and two transverse patches, and can measure the activity of lumbar flexion, extension, lateral bending and rotation.

[0004] In addition to sensitive performance, high wearing comfort of intelligent bandages is also essential, because long-term and continuous data collection is required in many practical scenarios. However, the sensing modules in most intelligent bandages still rely on traditional stretchable flexible substrates such as polydimethylsiloxane (PDMS), polyester (PET) and the like. They are usually bulky and sealed, which reduces the thermal and moisture comfort of the skin, further hindering their long-term usability. In order not to affect the original breathability of the bandage, breathable flexible sensing modules based on nanofiber films or textiles have been developed. Therefore, as a key research topic of next-generation medical electronics, it is urgent to develop a simple method for preparing breathable, comfortable and washable strain sensing modules. The patent with publication number CN115855323A discloses a high-performance waterproof breathable full-flexible piezoelectric tactile intelligent bandage for preparing intelligent skin, which has high pressure sensing sensitivity and will not cause discomfort after long-term contact with human skin.

[0005] In addition, the combination of multiple protection, multi-functional sensing, multi-modal sensing and diagnosis and treatment functions with bandages can broaden the application scenarios, make intelligent bandages more portable and functional, and provide new opportunities for human activity monitoring and personal healthcare. The patent with publication number CN215385074U proposes a multifunctional vest integrated with cooling, heart rate and body temperature monitoring and protection, which is low in cost, easy to use, high in reliability and light in structure, effectively integrates existing technologies and takes into account ease of use and comfort, making it more suitable for field training.

[0006] From the currently disclosed patents, intelligent bandages with motion monitoring function have high potential in human health monitoring. However, there are few new intelligent bandages that simultaneously meet the requirements of intelligence, comfort, multifunctionality, and protection. Obviously, designing a new type of porous and breathable sandwich structure intelligent bandage with electromagnetic shielding, electric heating, impact resistance, and sensing performance has a high application prospect in actual human health detection and healthcare. SUMMARY

[0007] To overcome the shortcomings of the prior art, the present application provides a new type of porous and breathable sandwich structure intelligent bandage and a preparation method thereof, which integrates electromagnetic shielding, electric heating, impact resistance, and sensing performance.

[0008] Specifically, the present application is realized by the following technical solutions:

[0009] A new type of porous and breathable sandwich structure intelligent bandage with electromagnetic shielding, electric heating, impact resistance, and sensing performance, the intelligent bandage is a sandwich structure, including a conductive non-woven fabric layer as an intermediate layer and a porous polyborosiloxane elastomer layer arranged on the inner and outer sides of the conductive non-woven fabric layer. The conductive non-woven fabric layer serves as a conductive functional layer and has electromagnetic shielding, electric heating, and sensing performance. The porous polyborosiloxane elastomer layer is a protective functional inner and outer layer that can resist external impact. Silver paste and copper foil serve as electrodes, which are soft, skin-friendly, and comfortable. The three layers of the sandwich structure intelligent bandage are all flexible porous materials, which are breathable and conformable.

[0010] Further, the conductive non-woven fabric has a conductive layer formed on the surface of the non-woven fabric by immersing a conductive material solution and drying. The non-woven fabric used is a common non-woven fabric material, including but not limited to TPU non-woven fabric, PU non-woven fabric, polyester non-woven fabric, and PE non-woven fabric, which is treated by ethanol ultrasonic to remove surface oil stains and impurities. The conductive material is MXene and AgNWs, which are nanoscale conductive materials with large specific surface area and high electrical conductivity.

[0011] Further, a conductive layer is formed on the surface of the non-woven fabric by alternately immersing the AgNWs solution and the MXene solution and drying. The structure of the AgNWs intercalated MXene reduces the contact resistance between the MXene layers to improve the conductivity of the conductive fabric. The number of immersions is 1-9; the AgNWs solution and the MXene immersion sequence includes but is not limited to one AgNWs followed by one MXene, one MXene followed by one AgNWs, two AgNWs followed by one MXene, two MXene followed by one AgNWs, and so on; and the drying temperature is 40-90℃.

[0012] Further, the porous polyborosiloxane elastomer is formed by vulcanizing polyborosiloxane and methyl vinyl silicone rubber in a hot press with benzoyl peroxide as a crosslinking agent. The polyborosiloxane resists external impact due to the rate-dependent effect, and the methyl vinyl silicone rubber has good shape retention after vulcanization. The mixture of the two has stable shape and impact resistance. Preferably, the mass ratio of the polyborosiloxane to the methyl vinyl silicone rubber is 30-70:70-30; preferably, the amount of the crosslinking agent is 4-10% of the total mass of the polyborosiloxane and the methyl vinyl silicone rubber; preferably, the hot pressing temperature for vulcanization is 90-100℃, the vulcanization pressure is 9-20kPa, and the vulcanization time is 9-15min.

[0013] Further, the porous polyborosiloxane elastomer has a thickness of 0.5-2mm, and has a hole array on the surface, with a hole diameter of 0.01-1mm and a distance between the centers of two holes of 0.02-2mm. The hole array can have a square, trapezoidal, triangular, or circular shape. The porous polyborosiloxane elastomer can be drilled by mechanical drilling or laser etching, which is simple and efficient and produces a uniform hole distribution with good air permeability.

[0014] Further, the polyborosiloxane is formed by crosslinking silicone oil and boric acid at a mass ratio of 20-30:1 at a temperature of 160-200℃.

[0015] The application also provides a preparation method of the porous air-permeable sandwich structure intelligent bandage as described above, which comprises the following steps:

[0016] Step 1, preparation of the porous polyborosiloxane elastomer

[0017] The silicone oil and boric acid are mixed at a mass ratio of 20-30:1, then heated in an oven at 160-200℃ until the system is solid, then n-octanoic acid is added and the reaction is continued for 20-30min to obtain the polyborosiloxane;

[0018] The polyborosiloxane and methyl vinyl silicone rubber with a mass ratio of 30%-70%:70%-30% and the vulcanizing agent benzoyl peroxide accounting for 4%-10% of the total mass of the polyborosiloxane and methyl vinyl silicone rubber are uniformly mixed by a rubber mixing machine, then are loaded into a mold with an inner layer thickness of 0.5-2 mm, and then are placed into a hot press, and the hot pressing temperature is set to 90-100 DEG C, the vulcanization pressure is set to 9-20 kPa, and the vulcanization time is set to 9-15 min, so that the polyborosiloxane elastomer is obtained;

[0019] The polyborosiloxane elastomer is punched by a silica gel puncher or a laser etching machine to form a hole array with a hole size of 0.01-1 mm and a distance of 0.02-2 mm between two hole centers, so that the porous polyborosiloxane elastomer is obtained;

[0020] Step 2, preparation of the conductive non-woven fabric layer

[0021] The non-woven fabric is ultrasonically cleaned with ethanol to remove impurities and oil stains on the surface of the non-woven fabric, then is alternately dipped in AgNWs solution and MXene solution and is dried at 40 DEG C-90 DEG C, so that the conductive non-woven fabric layer is obtained.

[0022] An electrode is formed on the surface of the conductive non-woven fabric by using silver paste and copper foil to form a conductive path.

[0023] Step 3, preparation of the intelligent bandage

[0024] The conductive non-woven fabric layer is adhered to the middle of the two layers of porous polyborosiloxane elastomers by using the adhesion of the porous polyborosiloxane elastomer, so that the porous and breathable sandwich structure intelligent bandage is obtained.

[0025] Compared with the prior art, the beneficial effects of the present application are as follows:

[0026] (1) The present application designs a new porous and breathable sandwich structure intelligent bandage, which integrates electromagnetic shielding, electric heating, impact resistance and sensing performance, can be widely used in human health monitoring, sports protection and personal health care fields, not only can realize the monitoring of the electrical signals generated by human activities, but also has the electric heating performance to relieve muscle tension, and at the same time, the electromagnetic shielding and impact resistance performance can provide multiple protection for the human body.

[0027] (2) The present application adopts the preparation method of alternately dipping MXene and AgNWs conductive materials on the surface of the non-woven fabric fibers, and designs a conductive fabric with electromagnetic shielding, electric heating and sensing performance.

[0028] (3) The present application adopts mechanical drilling or laser etching method to drill holes on the porous polyborosiloxane elastomer, and the drilling method is simple and efficient, and the distribution of the holes is uniform, so that the porous polyborosiloxane elastomer can meet the air permeability and resist external impact at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Optical photograph of the porous, breathable sandwich structure smart bandage (a) and its optical photographs of the application and removal on human skin (b and c). Figure 1 Figure 1

[0030] Figure 2 Optical microscope picture of the porous polyborosiloxane elastomer.

[0031] Figure 3 Appearance comparison of the polyborosiloxane elastomer and the polyborosiloxane after 4 weeks.

[0032] Figure 4 Rheological properties of the polyborosiloxane elastomer.

[0033] Figure 5 Electrical conductivity of the conductive nonwoven fabric with different alternating impregnation sequences.

[0034] Figure 6 Electromagnetic shielding properties of the conductive nonwoven fabric with different alternating impregnation sequences.

[0035] Figure 7 Electrothermal properties of the porous, breathable sandwich structure smart bandage.

[0036] Figure 8 Drop hammer impact resistance of the porous, breathable sandwich structure smart bandage and the conductive nonwoven fabric.

[0037] Figure 9 Water vapor transmission properties of the porous, breathable sandwich structure smart bandage and the conductive nonwoven fabric.

[0038] Figure 10 Sensitivity of the porous, breathable sandwich structure smart bandage.

[0039] Figure 11 Sensing properties of the porous, breathable sandwich structure smart bandage under 5%, 15%, 25%, 30% tensile strain.

[0040] Figure 12 Sensing properties of the porous, breathable sandwich structure smart bandage under 0.5 Hz, 1 Hz, 1.5 Hz, 2 Hz tensile frequency.

[0041] Figure 13 Structure schematic diagram of the porous, breathable sandwich structure smart bandage of the present application.

[0042] Figure 14 Implementation flowchart of the preparation method of the present application. DETAILED DESCRIPTION

[0043] ​​In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to examples. The following content is only an example and description of the concept of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the concept of the present application or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

[0044] The performance parameters of the samples prepared in the following examples were tested according to the following test methods, in which the conductive non-woven fabric layer corresponding to the test of the intelligent bandage is MA 1 / 1 :

[0045] A. The specific method for measuring the electrical properties of the conductive non-woven fabric layer in the porous breathable sandwich structure intelligent bandage is as follows:

[0046] The conductive non-woven fabric was connected with a copper foil with silver paste as an electrode, and an impedance meter test system (Solartron Analytical, AMETEK Advanced Measurement Technology, Inc.) was used to measure the electrical properties.

[0047] B. The specific method for measuring the rheological properties of the polysiloxane elastomer is as follows:

[0048] The polysiloxane elastomer was made into a film with a thickness of 1 mm and a diameter of 20 mm using a mold, and then a commercial rheometer (Physica MCR 302, Anton Paar Co., Austria) was used to characterize the shear hardening properties thereof.

[0049] C. The specific method for measuring the electrothermal properties of the porous breathable sandwich structure intelligent bandage is as follows:

[0050] The sample was placed on a printed sample holder, and an automatic range direct current power supply (IT8500, Aide Electronics Co., Ltd.) and a thermocouple (DT-3891G, Shenzhen Hengjia Machinery Industry Co., Ltd.) were used to collect temperature signals.

[0051] D. The specific method for measuring the protective performance of the porous breathable sandwich structure intelligent bandage under low speed impact is as follows:

[0052] The sample was placed on a force sensor (KD3005C, Yangzhou Gaoke), and a 0.55 kg hammer head was released from different heights using a drop hammer impact device (ZCJ1302-A, Meites Industry). After the sample was impacted, the force sensor amplified the signal through a charge amplifier (YE5853, Donghua Test), and finally a digital oscilloscope (Tektronix DPO 2014B) was used to collect data.

[0053] E. The specific way to measure the electromagnetic shielding performance of the new porous breathable sandwich structure intelligent bandage is as follows:

[0054] The sample was cut into a size of 3*3 cm and loaded into a vector network analyzer (AV3672, China Electronics Technology Instrument and Meter Co., Ltd.) to test the electromagnetic interference shielding performance of the sample in the 8-12 GHz region (x-band).

[0055] F. The specific way to measure the water vapor transmission performance of the new porous breathable sandwich structure intelligent bandage is as follows:

[0056] The sample was cut into a size of 2*2 cm and covered on the mouth of a glass bottle (10 mL capacity) filled with 10 mL of water. The bottle and the sample contact part were tied with an elastic band, and the edge part was sealed with paraffin to prevent gas leakage. The device was placed in a constant temperature oven at 30°C, and the weight of the whole device was measured every day. The reduced weight was the weight of water vapor evaporation.

[0057] G. The specific way to measure the sensing performance (including sensitivity, different strain stability and different frequency stability) of the new porous breathable sandwich structure intelligent bandage is as follows:

[0058] The tensile sensor used a sample of 1.5 cm x 3 cm. The sensing test was controlled by a dynamic mechanical analyzer (DMA 3200), which recorded the strain and frequency size by stretching the two ends of the sample with the dynamic mechanical analyzer clamps. The resistance signal was collected in real time by an impedance tester (ModuLab XM MTS).

[0059] Example 1

[0060] This example prepared a porous breathable sandwich structure intelligent bandage according to the following steps:

[0061] Step 1, Preparation of porous polyborosiloxane elastomer

[0062] The silicone oil and boric acid were mixed uniformly at a mass ratio of 30:1, then placed in an oven for heat treatment at 180℃ until the system was solid, then n-octanoic acid was added (silicone oil:n-octanoic acid = 100g:250μL) and the reaction was continued for 30min to obtain a polysiloxane-boron. The polysiloxane-boron and methyl vinyl silicone rubber at a mass ratio of 30%:70% and the vulcanizing agent benzoyl peroxide at 4% of the total mass of the polysiloxane-boron and methyl vinyl silicone rubber were mixed uniformly by a rubber mixer, then loaded into a mold with an inner layer thickness of 0.5mm, then placed in a hot press, set to a hot pressing temperature of 90℃, a vulcanization pressure of 18kPa, and a vulcanization time of 15min to obtain a polysiloxane-boron elastomer.

[0063] A PET film was engraved by a laser engraving machine to form a positioning template (hollow circle d = 1mm, the center distance between two adjacent circles was 3mm), then the polysiloxane-boron elastomer film was adhered to the punched PET film, and finally a silicone punching machine was used to punch holes from the polysiloxane-boron elastomer to the PET direction to obtain a porous polysiloxane-boron elastomer.

[0064] Step 2, MXene / AgNWs alternately impregnated non-woven fabric to make conductive non-woven fabric layer

[0065] Alternately impregnate MXene solution and AgNWs solution: first, the ethanol ultrasonic washed impurity non-woven fabric was immersed in a MXene solution with a concentration of 5mg / mL for 5s, and then dried in an oven at 90℃; then immersed in an AgNWs solution with a concentration of 5mg / mL for 5s, and then dried in an oven at 90℃.

[0066] The above-mentioned step of "alternately impregnating MXene solution and AgNWs solution" was repeated 4 times to obtain a conductive non-woven fabric layer alternately impregnated with MXene and AgNWs (named MA 1 / 1 ).

[0067] An electrode was formed on the surface of the conductive non-woven fabric by silver paste and copper foil to form a conductive path.

[0068] Step 3, preparation of intelligent bandage

[0069] The conductive non-woven fabric layer was placed between two layers of porous polysiloxane-boron elastomer. The size of the upper and lower porous polysiloxane-boron elastomer was slightly larger than that of the conductive non-woven fabric layer. Due to the viscosity of the porous polysiloxane-boron elastomer polymer, the conductive non-woven fabric layer could be successfully wrapped in the middle, i.e. a porous and breathable sandwich structure intelligent bandage was prepared.

[0070] Example 2

[0071] In this example, a porous and breathable sandwich structure intelligent bandage was prepared according to the following steps:

[0072] Step 1, preparation of porous polysiloxane-boron elastomer

[0073] The same as example 1.

[0074] Step 2, MXene / AgNWs alternately impregnated non-woven fabric to make conductive non-woven fabric layer

[0075] Alternately impregnate MXene twice and AgNWs once: first, impregnate the non-woven fabric washed by ultrasonic ethanol to remove impurities in the MXene solution with a concentration of 5 mg / mL for 5 s, and dry in the oven at 90°C; then, impregnate in the MXene solution with a concentration of 5 mg / mL for 5 s, and dry in the oven at 90°C; then, impregnate in the AgNWs solution with a concentration of 5 mg / mL for 5 s, and dry in the oven at 90°C.

[0076] Repeat the above "alternately impregnate MXene twice and AgNWs once" step for 3 times to obtain a conductive non-woven fabric layer alternately impregnated with MXene and AgNWs (named MA 2 / 1) .

[0077] Build electrodes on the surface of the conductive non-woven fabric through silver paste and copper foil to form a conductive path.

[0078] Step 3, preparation of the smart bandage

[0079] The same as example 1.

[0080] Example 3

[0081] This example prepares a porous breathable sandwich structure smart bandage according to the following steps:

[0082] Step 1, preparation of porous polyborosiloxane elastomer

[0083] The same as example 1.

[0084] Step 2, MXene / AgNWs alternately impregnated non-woven fabric to make conductive non-woven fabric layer

[0085] Alternately impregnate MXene once and AgNWs twice: first, impregnate the non-woven fabric washed by ultrasonic ethanol to remove impurities in the MXene solution with a concentration of 5 mg / mL for 5 s, and dry in the oven at 90°C; then, impregnate in the AgNWs solution with a concentration of 5 mg / mL for 5 s, and dry in the oven at 90°C; then, impregnate in the AgNWs solution with a concentration of 5 mg / mL for 5 s, and dry in the oven at 90°C.

[0086] Repeat the above "alternately impregnate MXene once and AgNWs twice" step for 3 times to obtain a conductive non-woven fabric layer alternately impregnated with MXene and AgNWs (named MA 1 / 2 ).

[0087] Build electrodes on the surface of the conductive non-woven fabric through silver paste and copper foil to form a conductive path.

[0088] Step 3, Preparation of the smart bandage

[0089] The same as example 1.

[0090] The electrical conductivity of the conductive non-woven fabric layer in the porous and breathable sandwich structure smart bandage prepared in examples 1-3 was tested respectively, and the test method was according to the aforementioned "A, specific way of measuring the electrical properties of the smart bandage", and the test results were as follows:

[0091] Sequence of alternating AgNWs and MXene impregnation MA 1 / 1 ]] MA 2 / 1 ]] MA 1 / 2 ]] Conductivity (S / mm 2 ) 7.66 3.77 6.57

[0092] Figure 1 It is an optical photo of the porous and breathable sandwich structure smart bandage, which shows that it has the properties of porous and breathable, soft and skin-friendly, adhesion and conformability. The polyborosiloxane elastomer is a transparent silicone gel material, and the conductive non-woven fabric is black.

[0093] Figure 2 It is an optical microscope picture of the porous polyborosiloxane elastomer, which shows that the hole cut of the porous polyborosiloxane elastomer obtained by mechanical drilling is smooth and the hole arrangement is regular.

[0094] Figure 3 It is a comparison picture of the appearance of the polyborosiloxane elastomer and the polyborosiloxane placed for 4 weeks, which shows that the polyborosiloxane elastomer has better shape retention than the polyborosiloxane, and cold flow will occur after placement.

[0095] Figure 4 It is the rheological property of the polyborosiloxane elastomer, which shows that the polyborosiloxane elastomer has a rate-dependent characteristic of shear hardening, and can be force protected.

[0096] Figure 5 It is the electrical conductivity of the conductive non-woven fabric with different alternating impregnation sequences, which shows that alternating impregnation of MXene and AgNWs can make the smart bandage have higher electrical conductivity, which is beneficial to the smart bandage to obtain electrical heating performance and electromagnetic shielding performance.

[0097] Figure 6 It is the electromagnetic shielding performance of the conductive non-woven fabric with different alternating impregnation sequences, which shows that alternating impregnation of MXene and AgNWs can make the smart bandage have high electromagnetic shielding effect.

[0098] Figure 7 It is the electrical heating performance of the porous and breathable sandwich structure smart bandage, which shows that alternating impregnation of MXene and AgNWs can make the smart bandage have high electrical heating effect.

[0099] Figure 8 It is the anti-drop hammer impact performance of the porous and breathable sandwich structure smart bandage and the conductive non-woven fabric, which shows that the porous polyborosiloxane elastomer can make the smart bandage have force protection performance.

[0100] Figure 9 The water vapor permeability of the porous breathable sandwich structure intelligent bandage and the conductive non-woven fabric shows that the intelligent bandage is porous and breathable, and has good thermal and humid comfort during wearing.

[0101] Figure 10 The sensing sensitivity of the porous breathable sandwich structure intelligent bandage shows that the alternating impregnation of MXene and AgNWs can make the intelligent bandage have high sensitivity.

[0102] Figure 11 The sensing performance of the porous breathable sandwich structure intelligent bandage under 5%, 15%, 25%, and 30% tensile strain shows that the alternating impregnation of MXene and AgNWs can make the intelligent bandage have high sensing stability.

[0103] Figure 12 The sensing performance of the porous breathable sandwich structure intelligent bandage under 0.5Hz, 1Hz, 1.5Hz, and 2Hz tensile frequency shows that the alternating impregnation of MXene and AgNWs can make the intelligent bandage have high sensing stability.

[0104] Figure 13 The structure diagram of the porous breathable sandwich structure intelligent bandage of the present application is specifically a sandwich structure of two layers of porous polyborosiloxane elastomer encapsulating conductive fabric, from the side view, the top layer and the bottom layer are porous polyborosiloxane elastomer, and the inner layer is conductive fabric; from the top view, the holes of the top layer of porous polyborosiloxane elastomer are arranged in order.

[0105] Figure 14 The implementation flowchart of the preparation method of the present application is as follows: on the one hand, the non-woven fabric is impregnated in the MXene solution and dried; then it is impregnated in the AgNWs solution and dried. The above steps are repeated to obtain the conductive non-woven fabric. On the other hand, the polyborosiloxane and methyl vinyl silicone rubber are mixed and vulcanized to obtain the polyborosiloxane elastomer, and then the mechanical drilling method is used to obtain the porous polyborosiloxane elastomer with regularly arranged holes. Finally, the porous polyborosiloxane elastomer is compounded with the conductive fabric, and the porous breathable sandwich structure intelligent bandage is made by using the adhesion of the porous polyborosiloxane elastomer itself.

[0106] Finally, it should be noted that: obviously, the above examples are only examples for clearly illustrating the present application, and are not limitations on the embodiments. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for preparing a porous breathable sandwich structure smart bandage with electromagnetic shielding, electric heating, impact resistance and sensing properties, characterized in that: The smart bandage has a sandwich structure, including a conductive non-woven fabric layer as an intermediate layer and a porous polyborosiloxane elastomer disposed on both the inner and outer sides of the conductive non-woven fabric layer. The preparation method of the smart bandage includes the following steps: Step 1: Preparation of porous polyborosiloxane elastomer Silicone oil and boric acid are uniformly mixed in a mass ratio of 20-30:1, and heat-treated in an oven at 160-200°C until the system is solid. Then, n-octanoic acid is added and the reaction is continued for 20-30 minutes to obtain polyborosiloxane. Polyborosiloxane and methyl vinyl silicone rubber in a mass ratio of 30% to 70%: 70% to 30% and a curing agent, benzoyl peroxide, accounting for 4% to 10% of the total mass of the polyborosiloxane and methyl vinyl silicone rubber, are mixed uniformly in a rubber mixer, loaded into a mold with an inner layer thickness of 0.5 to 2 mm, and then placed in a hot press. The hot pressing temperature, curing pressure, and curing time are set at 90 to 100° C., 9 to 20 kPa, and 9 to 15 minutes, to obtain a polyborosiloxane elastomer. The polyborosiloxane elastomer is made into a hole array with a pore size of 0.01-1 mm using a silicone puncher or a laser etcher, and the distance between the centers of two holes is 0.02-2 mm, thereby obtaining a porous polyborosiloxane elastomer; Step 2: Preparation of conductive non-woven fabric layer The non-woven fabric was ultrasonically removed of impurities and oil stains on the surface by ethanol, and then alternately immersed in AgNWs solution and MXene solution and dried at 40°C-90°C to obtain a conductive non-woven fabric layer. Building electrodes on the surface of the conductive non-woven fabric layer by silver paste and copper foil to form a conductive path; Step 3: Preparation of smart bandage Utilizing the adhesion of porous polyborosiloxane elastomer, a conductive non-woven fabric layer is adhered between two layers of porous polyborosiloxane elastomer to obtain a porous breathable sandwich structure smart bandage.

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