Epidermal sensor for multiple monitoring of human motion signals and preparation method thereof

Abstract

The invention provides an epidermal sensor for multiple monitoring of human motion signals, which comprises a porous elastomer substrate, a first electrode and a second electrode, the first electrode and the second electrode are arranged at two ends of the porous elastomer substrate, an electronegative material is deposited on a half part of the porous elastomer substrate, and an electropositive material is deposited on a half part of the porous elastomer substrate. The electronegative material and the electropositive material are both located in the hole, the first electrode and the electronegative material form a first friction pair, and the second electrode and the electropositive material form a second friction pair; the potential difference generated between the first electrode and the second electrode is used for measuring electromyographic signals, induced potentials are generated between the electronegative material and the first electrode and between the electropositive material and the second electrode, and the induced potentials are used for measuring friction electric signals; according to the invention, electromyographic signals and friction electric signals of muscle motion states can be reflected at the same time, and muscle motion can be fully reflected; the whole sensor is in a film shape and can be directly attached to the human muscle surface, and the problems of constraint, air tightness and the like are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field related to human motion monitoring, and in particular to an epidermal sensor for multiple monitoring of human motion signals and a preparation method thereof. Background Art

[0002] With the rapid development of microelectronics and material technology, a large number of new microelectronic devices with multiple functions and high integration are being developed, and they have shown unprecedented application prospects in various fields of people's daily lives. With the gradual increase in health awareness, more and more people are beginning to pay attention to the health of their sports. The monitoring of human motion signals is of vital importance for scientific and reasonable fitness and rehabilitation training. However, traditional motion monitoring equipment has problems such as lack of flexibility, lack of comfort, and difficulty in fully detecting human motion status with single signal acquisition. In order to solve these problems, it is extremely important to develop wearable epidermal sensors based on multi-sensing principles. Summary of the invention

[0003] The main purpose of the present invention is to overcome the above shortcomings and deficiencies of the prior art and to provide an epidermal sensor for multiple monitoring of human motion signals.

[0004] A skin sensor for multiple monitoring of human motion signals comprises a porous elastomer substrate, a first electrode and a second electrode arranged at both ends of the porous elastomer substrate, wherein the porous elastomer substrate is in the form of a porous film, a negatively charged material is deposited on the half of the porous elastomer substrate provided with the first electrode, and a positively charged material is deposited on the half of the porous elastomer substrate provided with the second electrode, wherein both the negatively charged material and the positively charged material are located in the holes, the first electrode and the negatively charged material form a first friction pair, and the second electrode and the positively charged material form a second friction pair; when the muscle relaxes or contracts, the potential difference generated between the first electrode and the second electrode is used to measure the electromyographic signal, and an induced potential is generated between the negatively charged material and the first electrode, and between the positively charged material and the second electrode, and the induced potential is used to measure the frictional electric signal.

[0005] The epidermal sensor of the present invention has two sensing principles, one is to measure electromyographic signals through electrodes, and the other is to measure muscle movement signals based on the principle of frictional power generation, namely triboelectric signals. Electromyographic signals can distinguish muscle movements under different forces, and triboelectric signals can distinguish muscle movements under different amplitudes. The present invention combines the two signals and uses them on the same sensor, which can more fully reflect muscle movements. At the same time, the epidermal sensor of the present invention is in the form of a film as a whole and can be directly attached to the surface of human muscle. It is more comfortable than other sensors and avoids problems such as restraint and airtightness.

[0006] In one embodiment of the present invention, the porous elastomer substrate is rectangular and is an elastomer in the form of a porous sponge.

[0007] In one embodiment, the elastomer is an elastic material such as polydimethylsiloxane, fluorinated silicone rubber, polyurethane, hydrogenated styrene-butadiene block copolymer, etc.

[0008] In one embodiment, the negatively charged material may be easily obtained electronic materials such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyimide, etc.

[0009] In one embodiment, the positively charged material can be gold nanoparticles, nylon or ethyl cellulose. The elastomer can be polydimethylsiloxane, fluorinated silicone rubber, polyurethane, or hydrogenated styrene-butadiene block copolymer.

[0010] In one embodiment, two short sides of the epidermal sensor are attached to the skin via medical tape or double-sided tape.

[0011] In one embodiment of the present invention, the first electrode and the second electrode are in strip shape, and the first electrode and the second electrode are flexible and stretchable conductive composite materials.

[0012] In one embodiment of the present invention, the flexible and stretchable conductive composite material is a carbon fiber / polymer composite material, a conductive fiber / elastic material composite material, or a conductive polymer / elastic material composite material.

[0013] In one embodiment, when the muscle contracts, an action potential is generated and propagates along the direction of the muscle, passing through the first electrode and the second electrode in turn, so that a potential difference is generated between the two electrodes, and the frequency of the electromyographic signal formed by the simultaneous superposition of multiple action potentials is in the range of 50 to 150 Hz. When the muscle moves, the friction pairs in the holes of the porous elastomer substrate are under the action of external forces. After contact and separation, the negatively charged material is negatively charged and the positively charged material is positively charged. These holes jointly generate an induced potential at the first electrode and the second electrode. When the muscle contracts, the distance between the negatively charged material and the first electrode, and the positively charged material and the second electrode decreases, and the induced potential decreases; when the muscle relaxes, the distance between the negatively charged material and the first electrode, and the positively charged material and the second electrode increases, and the induced potential increases. These changing induced potentials are triboelectric signals, which reflect the movement state of the muscle. The frequency of the triboelectric signal is below 10 Hz, and the electromyographic signal and the triboelectric signal are separated by a filter.

[0014] In one embodiment, conductive paste or conductive gel is applied to the first electrode and the second electrode, and the conductive paste or conductive gel is provided to reduce the contact impedance between the first electrode and the second electrode and the skin.

[0015] A method for preparing an epidermal sensor for multiple monitoring of human motion signals comprises the following steps:

[0016] Step 1, take a polyvinyl alcohol aqueous solution with a mass fraction of 5%-15%, apply it on a clean glass sheet, then place the glass sheet on a spin coater, spin coat at a speed of 200-500 rpm for 1-3 minutes, then place the glass sheet on a hot plate, and heat at 75-95° C. for 25-35 minutes to obtain a polyvinyl alcohol layer;

[0017] Step 2, attaching a mask to the polyvinyl alcohol layer, and then scraping the paste-like conductive composite material with a scraper to make it pass through the mask and deposit on the polyvinyl alcohol layer, and then peeling off the mask to obtain a patterned conductive composite material layer as an electrode;

[0018] Step 3, 5 g of liquid elastomer is mixed with 10 g of soluble particles, and coated on the polyvinyl alcohol layer;

[0019] Step 4, placing the glass sheet in an oven and heating it at 100-130° C. for 1.5-2.5 hours to completely cure the elastomer and the conductive composite material;

[0020] Step 5, placing the glass sheet in water and heating it at 80-95° C. for 7-10 hours, so that the soluble particles in the elastomer are completely dissolved to obtain a porous elastomer substrate, and the polyvinyl alcohol layer is also dissolved in water, and peeled off from the glass sheet to obtain a sample;

[0021] Step 6, immerse the lower half of the porous elastomer substrate in the negatively charged material solution with the midpoint of the long side as the boundary, soak for 25-40 minutes, then take it out and put it into a constant temperature drying oven, heat it at 65-85° C. for 1.5-2.5 hours, so that the solvent in the negatively charged material solution is initially and slowly evaporated, and then put it on a hot plate and heat it at 110-130° C. for 25-40 minutes to completely remove the residual solvent in the negatively charged material;

[0022] Step 7, immerse the other half of the porous elastomer substrate in the positive material solution for 25-40 minutes, then take it out and put it into a constant temperature drying oven, heat it at 65-85°C for 1.5-2.5h, so that the solvent in the positive material is initially and slowly evaporated, then put it on a hot plate and heat it at 110-130°C for 25-40min to completely remove the residual solvent in the positive material, and the sensor is manufactured;

[0023] In one embodiment, in step 3, the soluble particles are sucrose particles, salt particles, sodium carbonate particles, sodium bicarbonate particles or citric acid particles. Preferably, the soluble particles are sucrose particles.

[0024] In one embodiment, in step 6, the negatively charged material solution is a polytetrafluoroethylene emulsion, wherein the mass fraction of the polytetrafluoroethylene is 60%.

[0025] In one embodiment, in step 7, the positively charged material solution is selected from nano-gold colloid, wherein the content of the nano-gold particles is 0.2 mg / mL, and the particle size of the nano-gold particles is less than 20 nm.

[0026] When the human body is exercising, the epidermal sensor of the present invention is attached to the surface of the human muscle. The electromyographic signal and the frictional electric signal work together to form an AC pulse signal output in the electrode. In addition, the muscle strength and the amplitude of muscle movement are different in different exercise states, and the measured signal amplitude is different, so the size of muscle force and the size of movement amplitude can be distinguished, and the muscle movement can be monitored more comprehensively. Compared with the prior art, the epidermal sensor provided by the present invention has the following beneficial effects:

[0027] 1. Multifunctionality: Compared with the traditional sensor, which can hardly fully detect the human body movement status by collecting a single signal, the epidermal sensor of the present invention can analyze, weight and integrate multiple signals, and can obtain more comprehensive and accurate human body movement signals;

[0028] 2. Good wearability. The epidermal sensor of the present invention is made of flexible material and is in the form of a thin film, which can achieve good fit with human skin. The sensor is transferred from the human hand to the specific forearm muscle of the human body, which removes the restriction on the normal movement of the human hand. The porous elastomer substrate used has good flexibility and air permeability. Therefore, the epidermal sensor of the present invention has good wearability and comfort.

[0029] 3. Non-invasive. Compared with other monitoring methods, epidermal sensors do not need to penetrate the skin or enter the human body, and do not require surgical operations, which can reduce side effects such as infection and pain.

[0030] 4. High sensitivity. The epidermal sensor of the present invention has high precision and can accurately monitor the weak muscle movement signals of the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of an epidermal sensor for multiple monitoring of human motion signals of the present invention;

[0032] Figure 2It is a schematic diagram of the potential induction of the epidermal sensor for multiple monitoring of human motion signals of the present invention;

[0033] Figure 3 It is a schematic diagram of the structure of the epidermal sensor used for multiple monitoring of human motion signals of the present invention;

[0034] Figure 4 for Figure 3 A cross-sectional view of an epidermal sensor for multiple monitoring of human motion signals according to the present invention;

[0035] Figure 5 It is a schematic diagram of the structure of the epidermal sensor for multiple monitoring of human motion signals of the present invention from another angle;

[0036] Figure 6 It is a signal diagram measured by the epidermal sensor for multiple monitoring of human motion signals under different gripping forces of the present invention;

[0037] Figure 7 It is a signal diagram measured by the epidermal sensor for multiple monitoring of human motion signals under different grasping amplitudes of the present invention;

[0038] Figure 8 It is a schematic diagram of a method for preparing an epidermal sensor for multiple monitoring of human motion signals according to the present invention. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0044] The present invention provides an epidermal sensor for multiple monitoring of human motion signals, comprising a porous elastomer substrate, a first electrode and a second electrode arranged at both ends of the porous elastomer substrate, wherein the porous elastomer substrate is in the form of a porous film, a negatively charged material is deposited on the half of the porous elastomer substrate provided with the first electrode, and a positively charged material is deposited on the half of the porous elastomer substrate provided with the second electrode, wherein both the negatively charged material and the positively charged material are located in the holes, the first electrode and the negatively charged material form a first friction pair, and the second electrode and the positively charged material form a second friction pair; when the muscle is relaxed or contracted, the potential difference generated between the first electrode and the second electrode is used to measure the electromyographic signal, and an induced potential is generated between the negatively charged material and the first electrode, and between the positively charged material and the second electrode, and the induced potential is used to measure the frictional electric signal.

[0045] The epidermal sensor of the present invention can simultaneously measure the electromyographic signal and the triboelectric signal that can reflect the muscle movement state, and can more fully reflect the muscle movement. At the same time, the epidermal sensor of the present invention is in the form of a film as a whole and can be directly attached to the surface of human muscle. Compared with other sensors, it is more comfortable and avoids problems such as restraint and airtightness.

[0046] Embodiment 1

[0047] See also Figures 1 to 5 The present invention provides an epidermal sensor for multiple monitoring of human motion signals, comprising a porous elastomer substrate 1, a first electrode 2 and a second electrode 3 arranged at both ends of the porous elastomer substrate 1, the porous elastomer substrate 1 is in the shape of a porous film, a negatively charged material 4 is deposited on half of the porous elastomer substrate 1 provided with the first electrode 2, in this embodiment, the negatively charged material 4 is made of polytetrafluoroethylene, a positively charged material 5 is deposited on half of the porous elastomer substrate 1 provided with the second electrode 3, the positively charged material 5 is made of nano-gold particles, the negatively charged material 4 and the positively charged material 5 are both located in the pores of the porous elastomer substrate 1, the first electrode 2 and the negatively charged material 4 form a first friction pair, and the second electrode 3 and the positively charged material 5 form a second friction pair.

[0048] When the human body's muscles relax or contract, the potential difference generated between the first electrode 2 and the second electrode 3 is used to measure the myoelectric signal, and an induced potential is generated between the negatively charged material 4 and the first electrode 2, and between the positively charged material 5 and the second electrode 3. The induced potential is used to measure the frictional electric signal.

[0049] The epidermal sensor of the present invention has two sensing principles. One is to measure the electromyographic signal through the first electrode 2 and the second electrode 3, and the other is to measure the muscle movement signal based on the principle of frictional power generation, that is, the triboelectric signal. The electromyographic signal can distinguish the movement of the muscle under different forces, and the triboelectric signal can distinguish the movement of the muscle under different amplitudes. The present invention combines the two signals and uses them on the same sensor, which can more fully reflect the movement of the muscle. At the same time, the epidermal sensor of the present invention is in the form of a film as a whole and can be directly attached to the surface of human muscle. Compared with other sensors, it is more comfortable and avoids problems such as restraint and airtightness.

[0050] More specifically, see Figure 3The porous elastomer substrate 1 is rectangular, and the porous elastomer substrate 1 is a porous sponge-like elastomer 11, and the elastomer 11 is made of polydimethylsiloxane. When in use, the epidermal sensor is attached to the human epidermis near the muscle belly, one side of the electrode contacts the human skin, its long side follows the muscle direction, and the short side is perpendicular to the muscle direction. Among them, when the present invention is in use, the two short sides of the epidermal sensor are attached to the skin through medical tape or double-sided tape. More specifically, the first electrode 2 and the second electrode 3 are coated with conductive paste or conductive gel. The purpose of providing the conductive paste or conductive gel is to reduce the contact impedance between the first electrode 2 and the second electrode 3 and the skin.

[0051] More specifically, the first electrode 2 and the second electrode 3 are in strip shape, and the first electrode 2 and the second electrode 3 are flexible and stretchable conductive composite materials. The flexible and stretchable conductive composite materials are carbon fiber / polymer composite materials, conductive fiber / elastic material composite materials, and conductive polymer / elastic material composite materials.

[0052] More specifically, see Figure 2 When the muscle contracts, an action potential is generated and propagates along the direction of the muscle, passing through the first electrode 2 and the second electrode 3 in turn, so that a potential difference is generated between the two electrodes. The frequency of the electromyographic signal formed by the simultaneous superposition of multiple action potentials is in the range of 50 to 150 Hz. When the muscle moves, the friction pairs in the holes of the porous elastomer substrate 1 are contacted and separated under the action of external forces. The negatively charged material 4 is negatively charged and the positively charged material 5 is positively charged. These holes jointly generate induced potentials at the first electrode 2 and the second electrode 3. When the muscle contracts, the distance between the negatively charged material 4 and the positively charged material 5 decreases, and the induced potential decreases; when the muscle relaxes, the distance between the negatively charged material 4 and the first electrode 2, and the distance between the positively charged material 5 and the second electrode 3 increases, and the induced potential increases. These changing induced potentials are triboelectric signals, which reflect the movement state of the muscle. The frequency of the triboelectric signal is below 10 Hz. The electromyographic signal and the triboelectric signal are separated by a filter.

[0053] The main component of the myoelectric signal is in the range of 50-150Hz, and the frequency of the triboelectric signal is below 10Hz, so the two can be separated by a filter. The myoelectric signal can distinguish the movement of muscles at different strengths (the greater the muscle strength, the larger the myoelectric signal), and the triboelectric signal can distinguish the movement of muscles at different amplitudes (the greater the amplitude of muscle movement, the larger the triboelectric signal). The combination of the two signals can more fully reflect the movement of muscles.

[0054] See also Figure 6 , Figure 6 The signal diagram is obtained by the sensor provided by the present invention under different gripping forces. Figure 6It can be seen that under different grasping forces, the amplitude of the friction electric signal remains basically unchanged, while the amplitude of the electromyographic signal changes significantly, and the greater the grasping force, the greater the amplitude of the electromyographic signal.

[0055] See also Figure 7 , Figure 7 The signal diagram is measured by the sensor provided by the present invention under different grasping amplitudes, from Figure 7 It can be seen that under different grasping amplitudes, the amplitude of the electromyographic signal remains basically unchanged, while the amplitude of the triboelectric signal changes significantly, and the larger the grasping amplitude, the larger the amplitude of the triboelectric signal.

[0056] Embodiment 2

[0057] See also Figure 8 The present invention provides a method for preparing an epidermal sensor for multiple monitoring of human motion signals, comprising the following steps:

[0058] Step 1, take a polyvinyl alcohol aqueous solution 7 with a mass fraction of 5%-15%, apply it on a clean glass sheet 6, then place the glass sheet 6 on a spin coater, and spin coat it at a speed of 200-500 rpm for 1-3 minutes, then place the glass sheet 6 on a hot plate, and heat it at 75-95° C. for 25-35 minutes to obtain a polyvinyl alcohol layer;

[0059] Preferably, the mass fraction of the polyvinyl alcohol aqueous solution 7 is 8%-12%, the glass sheet 6 is spin-coated at a speed of 250-350 rpm for 1.5-2.5 minutes, and heated at 75-85° C. for 25-30 minutes. More preferably, the mass fraction of the polyvinyl alcohol aqueous solution 7 is 10%, the glass sheet 6 is spin-coated at a speed of 300 rpm for 2 minutes, and heated at 80° C. for 30 minutes.

[0060] Step 2, attaching a mask 8 to the polyvinyl alcohol layer, and then scraping a paste of conductive composite material 10 with a scraper 9, so that it passes through the mask and is deposited on the polyvinyl alcohol layer, and then peeling off the mask to obtain a patterned conductive composite material layer as an electrode;

[0061] Step 3: Mix 5-10g of liquid elastomer 11 with 10-20g of soluble particles 12, and apply them on the polyvinyl alcohol layer; preferably, 5g of liquid elastomer 11 is mixed with 10g of soluble particles 12. The mass ratio of prepolymer to curing agent in the elastomer 11 is 10:1.

[0062] Step 4: Place the glass sheet 6 in an oven and heat it at 100-130° C. for 1.5-2.5 hours to completely cure the elastomer 11 and the conductive composite material layer; preferably, the curing is performed by heating at 120° C. for 2 hours.

[0063] Step 5: Place the glass sheet 6 in water 13 and heat it at 80-95°C for 7-10 hours to completely dissolve the soluble particles 12 in the elastomer 11 to obtain a porous elastomer substrate 1. At the same time, the polyvinyl alcohol layer is also dissolved in water and peeled off from the glass sheet. Preferably, place the glass sheet 6 in water 13 and heat it at 90°C for 8 hours.

[0064] Step 6, immerse the lower half of the porous elastomer substrate 1 in the negatively charged material solution 14 with the midpoint of the long side as the boundary, soak for 25-40 minutes, then take it out and put it into a constant temperature drying oven, heat it at a temperature of 65-85°C for 1.5-2.5h, so that the solvent in the negatively charged material solution 14 evaporates slowly and initially, then place it on a hot plate, and heat it at a temperature of 110-130°C for 25-40min to completely remove the residual solvent in the negatively charged material to obtain a negatively charged material deposition layer 4; wherein, preferably, the immersion time is 30 minutes, and the temperature is heated at 70°C for 2h, so that the solvent in the negatively charged material solution 14 evaporates slowly and initially, and then place it on a hot plate and heat it at a temperature of 120°C for 30min.

[0065] Step 7, immerse the other half of the porous elastomer substrate 1 in the positively charged material solution 15 for 25-40 minutes, then take it out and put it into a constant temperature drying oven, heat it at 65-85°C for 1.5-2.5h, so that the solvent in the positively charged material solution 15 is initially and slowly evaporated, then put it on a hot plate, and heat it at 110-130°C for 25-40min to completely remove the residual solvent in the positively charged material solution 15 to obtain the positively charged material deposition layer 5, and the sensor is manufactured; wherein, preferably, the immersion time is 30 minutes, then take it out and put it into a constant temperature drying oven, heat it at 70°C for 2h, so that the solvent in the positively charged material solution 15 is initially and slowly evaporated, then put it on a hot plate and heat it at 120°C for 30min.

[0066] In one embodiment, in step 3, the soluble particles are sucrose particles.

[0067] In one embodiment, in step 6, the negatively charged material solution 14 is a polytetrafluoroethylene emulsion, wherein the mass fraction of the polytetrafluoroethylene is 60%.

[0068] In one embodiment, in step 7, the positively charged material solution 15 is selected from nano-gold colloid, the content of nano-gold particles is 0.2 mg / mL, and the particle size of the nano-gold particles is less than 20 nm.

[0069] When the human body exercises, the epidermal sensor of the present invention is attached to the surface of the human muscle. The electromyographic signal and the frictional electric signal work together to form an AC pulse signal output in the electrode. The muscle strength and the amplitude of the muscle movement are different in different exercise states, and the measured signal amplitude is different, so the size of the muscle force and the amplitude of the movement can be distinguished, and the muscle movement can be monitored more comprehensively.

[0070] In view of the problem that it is difficult to fully detect the human body's motion status by collecting a single signal from a common sensor, the multi-sensing principle analyzes, weights and integrates multiple signals to obtain more comprehensive and accurate human motion signals. Secondly, the epidermal sensor is a sensor that can be directly attached to the skin to measure physiological signals. Compared with other sensors, it is more comfortable and avoids problems such as restraint and airtightness. At the same time, the epidermal sensor can effectively record the state of human muscle movement, and can also accurately record physiological indicators such as heart rate and breathing. Therefore, it has broad application prospects in motion monitoring. The combination of these technologies provides a technical basis for the development of multi-sensing principle epidermal sensors for human motion signal detection. In practical applications, this technology can realize efficient, accurate and convenient human motion monitoring, which is of great significance to the majority of sports enthusiasts and rehabilitation patients.

[0071] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An epidermal sensor for multiple monitoring of human motion signals, characterized in that: It includes a porous elastomer substrate, a first electrode and a second electrode arranged at both ends of the porous elastomer substrate, the porous elastomer substrate is in the shape of a porous film, half of the porous elastomer substrate provided with the first electrode is deposited with a negatively charged material, and half of the porous elastomer substrate provided with the second electrode is deposited with a positively charged material, the negatively charged material and the positively charged material are both located in the holes, the first electrode and the negatively charged material form a first friction pair, and the second electrode and the positively charged material form a second friction pair; when the muscle is relaxed or contracted, the potential difference generated between the first electrode and the second electrode is used to measure the electromyographic signal, and an induced potential is generated between the negatively charged material and the first electrode, and between the positively charged material and the second electrode, and the induced potential is used to measure the frictional electric signal.

2. The epidermal sensor for multiple monitoring of human motion signals according to claim 1, characterized in that: The negatively charged material may be polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride or polyimide.

3. The epidermal sensor for multiple monitoring of human motion signals according to claim 1, characterized in that: The positively charged material may be gold nanoparticles, nylon or ethyl cellulose.

4. The epidermal sensor for multiple monitoring of human motion signals according to claim 1, characterized in that: The porous elastic body substrate is rectangular and is an elastic body in the shape of a porous sponge.

5. The epidermal sensor for multiple monitoring of human motion signals according to claim 4, characterized in that: The elastomer is polydimethylsiloxane, fluorinated silicone rubber, polyurethane or hydrogenated styrene-butadiene block copolymer.

6. The epidermal sensor for multiple monitoring of human motion signals according to claim 1, characterized in that: The first electrode and the second electrode are in strip shape, and the first electrode and the second electrode are flexible and stretchable conductive composite materials.

7. The epidermal sensor for multiple monitoring of human motion signals according to claim 6, characterized in that: The flexible and stretchable conductive composite material is a carbon fiber / polymer composite material, a conductive fiber / elastic material composite material, or a conductive polymer / elastic material composite material.

8. The epidermal sensor for multiple monitoring of human motion signals according to claim 1, characterized in that: The frequency of the electromyographic signal is within the range of 50 to 150 Hz, the frequency of the frictional electric signal is below 10 Hz, and the electromyographic signal and the frictional electric signal are separated by a filter.

9. A method for preparing an epidermal sensor for multiple monitoring of human motion signals, characterized in that: The steps include: Step 1, take a polyvinyl alcohol aqueous solution with a mass fraction of 5%-15%, apply it on a clean glass sheet, then place the glass sheet on a spin coater, spin coat at a speed of 200-500 rpm for 1-3 minutes, then place the glass sheet on a hot plate, and heat at 75-95° C. for 25-35 minutes to obtain a polyvinyl alcohol layer; Step 2, attaching a mask to the polyvinyl alcohol layer, and then scraping the paste-like conductive composite material with a scraper to make it pass through the mask and deposit on the polyvinyl alcohol layer, and then peeling off the mask to obtain a patterned conductive composite material layer as an electrode; Step 3, mixing 5 g of liquid elastomer with 10 g of soluble particles, and coating the mixture on the polyvinyl alcohol layer; Step 4, placing the glass sheet in an oven and heating it at 100-130° C. for 1.5-2.5 hours to completely cure the elastomer and the conductive composite material; Step 5, placing the glass sheet in water and heating it at 80-95° C. for 7-10 hours, so that the soluble particles in the elastomer are completely dissolved to obtain a porous elastomer substrate, and the polyvinyl alcohol layer is also dissolved in water, and peeled off from the glass sheet to obtain a sample; Step 6, immerse the lower half of the porous elastomer substrate in a negatively charged material solution with a mass fraction of 40% to 60% at the midpoint of the long side for 25-40 minutes, then take it out and put it in a constant temperature drying oven, heat it at a temperature of 65-85° C. for 1.5-2.5 hours, so that the solvent in the negatively charged material solution is initially and slowly evaporated, and then put it on a hot plate and heat it at a temperature of 110-130° C. for 25-40 minutes to completely remove the residual solvent in the negatively charged material; Step 7, immerse the other half of the porous elastomer substrate in the positively charged material solution for 25-40 minutes, then take it out and put it into a constant temperature drying oven, heat it at 65-85 ° C for 1.5-2.5 hours, so that the solvent in the positively charged material solution evaporates slowly, and then place it on a hot plate and heat it at 110-130 ° C for 25-40 minutes to completely remove the residual solvent in the positively charged material. The sensor is manufactured.

10. The method for preparing the epidermal sensor for multiple monitoring of human motion signals according to claim 9, characterized in that: In step 3 and step 5, the soluble particles are sucrose particles, salt particles, sodium carbonate particles, sodium bicarbonate particles or citric acid particles.

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