Flexible self-powered muscle paste with high flexibility and capable of monitoring human body motion signals

Abstract

The invention discloses a flexible self-powered muscle paste with high flexibility and capable of monitoring human body motion signals. The flexible self-powered muscle paste is a wearable electronic sensing device of a three-layer structure. The middle layer is a ferroelectric electret, and a large number of holes which are different in size and distributed randomly are formed in the ferroelectric electret. The upper layer and the lower layer are electrode layers, so that the muscle paste has good electrical performance. According to the muscle paste capable of monitoring the human body motion signals, the ferroelectric electret containing a large number of artificial holes is prepared through the high-molecular polymer, the absolute ethyl alcohol and the flexible electrode, the piezoelectric effect is achieved after high-voltage processing, and the motion signals can be monitored and collected in a self-powered mode. The prepared muscle paste has super-strong flexibility and flexibility and can be worn on joints or muscles of a human body like electronic skin, and when an athlete begins to move, the muscle paste with the piezoelectric effect can collect movement signals and transmit the signals to a microprocessor, so that monitoring and checking of the movement signals are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of micro-electromechanical systems and wearable devices, and specifically relates to a highly stretchable, flexible, self-powered muscle patch that can monitor human motion signals. The muscle patch can be used to monitor the physical state of humans or animals during exercise, grasp real-time motion information, and provide accurate information guarantee for guiding physical movement behavior. Background Art

[0002] With the rapid development of artificial intelligence, big data and the Internet of Things, all aspects of daily life are changing, and sports are no exception. More and more sports enthusiasts and professional athletes are beginning to pay attention to the real-time sports information generated during physical exercise. By obtaining physical information during exercise, they can guide and improve standard movements, and at the same time reflect the health status of the body.

[0003] At present, the general public usually uses electronic devices such as smart bracelets and smart watches to collect information such as pulse and heart rate during exercise, which indirectly reflects the body's movement information; while professional athletes use a variety of sensor devices connected through complex circuits to monitor a single sport according to the characteristics of the sport. On the one hand, these traditional methods cannot accurately monitor body movement information and cannot provide precise guidance for sports behavior; on the other hand, with the diversification of sports types, the cost of monitoring body movement information for professional athletes is getting higher and higher, and different sports methods require the construction of different monitoring systems.

[0004] Traditional motion monitoring systems are usually composed of a number of traditional electronic sensors such as single-chip microcomputers, power modules, pedometers, heart rate monitors, GPS locators, accelerometers, etc., which monitor human motion through software programs under external power supply. Due to the large number of various sensors, the power consumption is large during operation, and the sensors are not flexible and cannot be directly attached to human skin, so the sensitivity of monitoring motion signals is not high.

[0005] Traditional sports muscle patch is a human skin patch made of waterproof elastic cotton cloth with good elasticity. It is usually attached by athletes to the joints of the body or the muscles that mainly exert force. Because of its good flexibility and elasticity, traditional sports muscle patch can effectively avoid injuries caused by muscle imbalance, incorrect posture, blood circulation and lymphatic return, incorrect exercise posture, etc.; at the same time, it can relieve muscle pain, congestion, edema, and joint effusion, so that muscles and joints can be relaxed. Although traditional sports muscle patch can be attached to the surface of the human body like human skin and will not fall off due to human movement, it cannot be used to monitor body movement information because it does not have the function of information collection and collection.

[0006] Ferroelectric electret is a non-polar material without molecular dipoles inside. These ferroelectric electrets usually contain a large number of randomly distributed holes of different sizes. These holes will form artificial dipoles after being charged in a high-voltage electric field, thereby being able to exhibit the same piezoelectric effect as piezoelectric materials. When subjected to external pressure, the ferroelectric electret with piezoelectric effect will generate a corresponding electrical signal. Due to this characteristic of ferroelectric electret, sensors made using ferroelectric polymers will have the advantages of strong piezoelectricity, self-powered, low acoustic impedance, low cost, and high sensitivity.

[0007] Based on the characteristics of the above-mentioned traditional sports muscle patches and the properties of ferroelectric electret materials, the sports muscle patches made of ferroelectric electret materials will have the advantages of strong stretchability, flexibility, environmentally friendly self-power supply, low cost, high sensitivity, etc., and can be attached to the human body surface like artificial electronic skin to monitor human movement information in real time. Summary of the invention

[0008] In order to solve the above problems, the present invention discloses a highly stretchable, flexible, self-powered muscle patch that can monitor human motion signals, which can be stably attached to muscles or joints of the human body. When the muscles or joints of the body move, it can collect motion information in real time, and the athlete can make corrections to meet the standard according to the collected data; and for people with disabilities, the muscle patch can monitor the rehabilitation status in real time, which helps to carry out rehabilitation training efficiently.

[0009] To achieve the above object, the technical solution of the present invention is as follows: The muscle patch, which is highly stretchable, flexible, self-powered and can monitor human motion signals, is a wearable electronic sensor device with a three-layer structure. The middle layer is a ferroelectric electret, which contains a large number of holes of different sizes and random distribution. The upper and lower layers are electrode layers to ensure that the muscle patch has good electrical properties.

[0010] The middle layer of the highly stretchable flexible self-powered muscle patch capable of monitoring human motion signals described in the present invention uses a high molecular polymer aliphatic aromatic random copolyester (Ecoflex) as a raw material, which is mixed with anhydrous ethanol, stirred evenly and then cured at high temperature to form a polymer ferroelectric material containing a large number of holes inside, which has super flexibility and stretchability.

[0011] The upper and lower layers of the muscle patch with strong elasticity and self-powered function for monitoring human motion signals described in the present invention are electrode layers. Since the middle layer has super flexibility and elasticity, the upper and lower electrode layers cannot use traditional electrode layer materials, and it is necessary to prepare an electrode layer that is also flexible and stretchable. Therefore, laser-induced graphene is used as the upper and lower surface electrodes of the muscle patch in the present invention. This electrode is not only flexible, but also exhibits very good electrical conductivity in a stretched state.

[0012] The highly stretchable, flexible, self-powered muscle patch that can monitor human motion signals described in the present invention needs to be polarized under the action of a high-voltage electric field. After the polarization treatment, the holes in the high-molecular polymer in the middle layer of the muscle patch will form a large number of artificial electric dipoles, which, combined with the flexible electrodes on the upper and lower surfaces of the muscle patch, will form a wearable electronic muscle patch with a significant piezoelectric effect.

[0013] The flexible self-powered muscle patch with strong elasticity and capable of monitoring human motion signals described in the present invention will have a significant piezoelectric effect after polarization is completed under the action of a high-voltage electric field. At present, traditional hard piezoelectric materials are not flexible, so they only have longitudinal piezoelectric effects; in recent years, most of the new polymers with piezoelectric effects after polarization treatment are flexible, but have poor ductility and elasticity, resulting in a small transverse piezoelectric effect and low sensitivity. Therefore, the currently common materials with piezoelectric effects cannot be used to prepare electronic muscle patches. However, the flexible self-powered muscle patch with strong elasticity and capable of monitoring human motion signals designed by the present invention uses a polymer Ecoflex as a base material, and cooperates with independently prepared laser-induced graphene as an electrode material to prepare a ferroelectric electret that is not only flexible, but also has both ductility and elasticity. It has longitudinal piezoelectric effects and transverse piezoelectric effects, and has high sensitivity. After being prepared into a muscle patch, it will deform with the joint muscles like an electronic skin, and then collect high-precision motion signals.

[0014] The muscle patch with strong stretchability, flexibility, self-power supply and the ability to monitor human motion signals described in the present invention is encapsulated with a polyurethane (PU) medical adhesive transparent waterproof film and then attached to the surface of human skin. The upper and lower electrode surfaces of the muscle patch connect the signals to the computer terminal through two leads, and real-time motion signals can be collected through a data acquisition system.

[0015] The beneficial effects of the present invention are: (1) The core technology of the highly stretchable and flexible self-powered muscle patch designed by the present invention, which can monitor human motion signals, is the use of polymer Ecoflex and laser-induced graphene to prepare a flexible and highly stretchable ferroelectric electret nanogenerator. The ferroelectric electret nanogenerator has the remarkable feature of self-power.

[0016] (2) The flexible self-powered muscle patch designed by the present invention can monitor human motion signals. Due to its strong flexibility and stretchability, the muscle patch can be adapted to the motion process of various joints of the human body, thereby accurately collecting motion information. At the same time, its self-powered feature can greatly reduce energy pollution and improve environmental adaptability and durability.

[0017] (3) The present invention is a more suitable application of the ferroelectric electret nanogenerator in the human body, but it is not limited to being used as a muscle patch that can monitor human motion signals. The present invention can be used in any application involving force change sensing, such as the collection of animal action data, monitoring of the stability of submarine equipment, and many other application scenarios.

[0018] (4) The muscle patch designed and proposed by the present invention utilizes the piezoelectric effect of the ferroelectric electret nanogenerator prepared by the polymer Ecoflex and laser-induced graphene to realize the collection of motion signals. Its piezoelectric effect is positively correlated with the number of artificial holes in the preparation process within a certain range. Since the holes inside the ferroelectric electret nanogenerator are formed by doping anhydrous ethanol in the polymer Ecoflex, the number of artificial holes can be changed by controlling the doping amount of anhydrous ethanol during the preparation process, thereby regulating the piezoelectric effect of the ferroelectric electret nanogenerator to adapt to the device sensitivity in different application scenarios.

[0019] (5) The middle layer of the highly stretchable flexible self-powered muscle patch that can monitor human motion signals proposed by the present invention is a polymer Ecoflex, which is a highly stretchable material. Since the upper and lower surfaces of the muscle patch are laser-induced graphene, through electron microscope observation, it is like a "forest" of graphene electrodes covering the surface of Ecoflex, which enhances the stretchability of the device, making the muscle patch proposed by the present invention more stretchable than the polymer Ecoflex. Therefore, it can adapt to most high-intensity exercise behaviors and improve the durability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a highly stretchable, flexible, self-powered muscle patch that can monitor human motion signals and is placed at the elbow and wrist of a human body for motion monitoring; Figure 2 It is a three-dimensional structural diagram of a muscle patch with strong stretchability, flexibility, self-power supply and the ability to monitor human motion signals; Figure 3 It is a schematic cross-sectional view of a highly stretchable, flexible, self-powered muscle patch that can monitor human motion signals; Figure 4 This is a three-dimensional structure diagram of a muscle patch with strong elasticity, self-powered, and capable of monitoring human motion signals after stretching and twisting; Figure 5 This is a schematic diagram of a muscle patch that is highly stretchable, flexible, self-powered, and can monitor human motion signals after being encapsulated using a polyurethane (PU) medical adhesive transparent waterproof film.

[0021] List of Figure Symbols: 1. Muscle patch, 2. Microprocessor, 3. Wrist signal, 4. Elbow signal, 5. Electrode layer, 6. Ferroelectric electret, 7. Holes, 8. Wires, 9. Waterproof film. DETAILED DESCRIPTION

[0022] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0023] The muscle patch with strong elasticity and self-powered function for monitoring human motion signals described in the present invention is a new type of wearable electronic sensor, which has a very similar appearance and basic functions to the traditional sports muscle patch used by athletes in daily life. Compared with the traditional sports muscle patch, the present invention can not only realize the functions of the traditional sports muscle patch - flexibility, elasticity, and relieve muscle pain, congestion, edema and other problems, but also truly realize the real-time collection of human joint and muscle motion information. For professional athletes, they can correct their movements according to the real-time collected motion information; and for people with disabilities, the muscle patch proposed by the present invention can monitor the rehabilitation situation in real time, which is helpful for efficient rehabilitation training. The realization of the present invention benefits from the excellent flexibility and elasticity of the polymer Ecoflex. A large number of artificial holes are prepared by mixing with anhydrous ethanol; the upper and lower surfaces of Ecoflex are combined with laser-induced graphene as flexible electrodes to provide good conductivity for the muscle patch sensor. Finally, the muscle patch is encapsulated by a polyurethane (PU) medical adhesive transparent waterproof film and worn on the joints or muscles of the human body to realize the collection of motion signals.

[0024] The muscle patch described in the present invention is a wearable electronic sensor device with a three-layer structure and a flexible, self-powered structure with strong stretchability and capable of monitoring human motion signals. The middle layer is a ferroelectric electret, which contains a large number of holes of different sizes and random distribution. The upper and lower layers are electrode layers to ensure that the muscle patch has good electrical properties.

[0025] When in use, the muscle patch 1 of the present invention is worn on the wrist and elbow of the human body, two wires 8 are connected to the surface electrode 5 through the carbon conductive glue, and the other end of the wire 8 is connected to the microprocessor 2. Figure 1 As shown, when the human body's wrist and elbow start to move, the muscle patch starts to collect motion signals, and the signals are transmitted to the microprocessor 2 through wires. After display processing by the microprocessor 2, the wrist signal 3 and the elbow signal 4 are displayed on the display.

[0026] The invention discloses a highly stretchable, flexible, self-powered muscle patch capable of monitoring human motion signals, and its preparation method is as follows: 1. Make one side of the electrode first According to the size of the muscle patch, a polyimide (PI) film slightly larger than the length and width of the muscle patch was selected, fixed to the center of the aluminum plate with ordinary tape and placed in a carbon dioxide laser cutting machine. The electrode shape was imported into the carbon dioxide laser cutting machine through drawing software and the polyimide (PI) film was engraved and burned at a suitable working power. At this time, a layer of "velvety" laser-induced graphene was prepared on the polyimide (PI) film on the surface of the aluminum plate.

[0027] 2. Make a half-layer ferroelectric electret (the ferroelectric electret is made in two steps) The polymer Ecoflex is mixed with liquid A and liquid B in a ratio of 1:1. After adding a certain amount of anhydrous ethanol, a blender is used for high-speed stirring (the mass ratio of the polymer Ecoflex to anhydrous ethanol is 50:1, and the stirring speed is 3000 rpm) to fully mix the anhydrous ethanol and the liquid polymer Ecoflex. Then, the mixed solution is poured into the laser-induced graphene on the polyimide (PI) film until the laser-induced graphene is completely immersed. After removing the excess mixed solution, the aluminum plate is placed on a heating table. After heating and curing at 135°C for 5 minutes, a blade is used to peel off the cured film from the aluminum plate from one corner of Ecoflex to obtain a film with an electrode on one side and artificial holes inside.

[0028] 3. Make the remaining half Repeat the above manufacturing process of laser-induced graphene, and pour the mixed solution of Ecoflex and anhydrous ethanol into the newly manufactured laser-induced graphene (to make another half layer of ferroelectric electret), place the electrode-free side of the previously prepared film on the surface of the solution, and place the whole film on a heating table. After heating and curing at 135°C for 5 minutes, peel off the sample in the same way as above to obtain the muscle patch body.

[0029] 4. Polarization treatment After the above manufacturing work is completed, because the above polymer Ecoflex is a completely non-polar material, it does not have any piezoelectric effect, and the internal artificial holes 7 do not contain any charge, so high voltage polarization is required. After the manufactured muscle patch is placed under a high voltage of 20kV for 5 minutes, a highly oriented giant dipole is formed inside the hole 7. The upper and lower surfaces of each hole 7 carry equal amounts of heterogeneous charges. At this time, the upper and lower surfaces of the muscle patch will sense the free charges in the environment and adsorb them on the surface, forming a piezoelectric effect.

[0030] Because the new muscle patch proposed by the present invention is both flexible and highly stretchable, when the muscle patch is stretched and twisted, the upper and lower surface electrodes 5 are flexible electrodes and will not be affected by the stretching and twisting to change the electrical properties. Figure 4As shown, the artificial hole 7 in the insulating layer 6 changes from a sphere to an ellipsoid under the influence of stretching and twisting, and the dipole moment in the hole changes. Because it has a piezoelectric effect, a piezoelectric signal will also be generated under stretching and twisting.

[0031] According to the requirements, the motion signal collected by the muscle patch needs to be transmitted to the microprocessor 2 for display. Therefore, two electrical wires 8 are used to connect the surface electrodes 5 through the carbon conductive glue to ensure that the signal can be output smoothly. Figure 5 As shown, since the muscle patch needs to be placed on the joints or muscles of the human body, the muscle patch 1 can be stably worn on the joints or muscles of the human body after being packaged with a polyurethane (PU) medical adhesive transparent waterproof film 9. At the same time, the stability of the electrical performance of the muscle patch can also be ensured after packaging.

[0032] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A flexible, self-powered muscle patch with strong elasticity that can monitor human motion signals, characterized by: The muscle patch is a wearable electronic sensor device with a three-layer structure; the middle layer is a ferroelectric electret, which contains a large number of holes of different sizes and random distribution; the upper and lower layers are electrode layers to ensure that the muscle patch has good electrical properties.

2. The highly stretchable, flexible, self-powered muscle patch capable of monitoring human motion signals according to claim 1, characterized in that: The outer surface of the electrode layer is covered with a polyurethane medical adhesive transparent waterproof film.

3. A method for preparing a muscle patch with strong elasticity, self-powered and capable of monitoring human motion signals, characterized in that: The specific steps are as follows: (1) First make one side of the electrode According to the size of the muscle patch, a polyimide film 1 cm larger in length and width than the muscle patch was selected, fixed to the center of the aluminum plate with ordinary tape and placed in a carbon dioxide laser cutting machine. The electrode shape was imported into the carbon dioxide laser cutting machine through drawing software and the surface of the polyimide film was engraved and burned at a suitable working power. After burning, a layer of "velvet-like" laser-induced graphene was prepared on the polyimide film. (2) Making a half-layer ferroelectret The polymer Ecoflex is prepared by mixing liquid A and liquid B in a ratio of 1:1, adding a certain amount of anhydrous ethanol and stirring at high speed with a stirrer to fully mix the anhydrous ethanol and the liquid polymer Ecoflex, then pouring the mixed solution into the laser-induced graphene on the polyimide film prepared in step (1) until the laser-induced graphene is completely immersed, removing the excess mixed solution, placing the aluminum plate on a heating table, heating and curing at 135° C. for 5 minutes, and then using a blade to peel the cured film from the aluminum plate from one corner of the Ecoflex to obtain a film having an electrode on one side and artificial holes inside; (3) Make the remaining half Repeat the above-mentioned laser-induced graphene manufacturing process, and similarly pour the mixed solution of Ecoflex and anhydrous ethanol into the newly manufactured laser-induced graphene, place the electrode-free side of the previously prepared film on the solution surface, and place the whole film on a heating table. After heating and curing at 135°C for 5 minutes, peel off the sample in the same manner as step (2) to obtain the muscle patch body. (4) Polarization treatment After the manufactured muscle patch body is polarized under a high voltage of 20kV for 5 minutes, a highly directional giant dipole is formed inside the hole. The upper and lower surfaces inside each hole carry equal amounts of opposite charges. At this time, the upper and lower surfaces of the muscle patch will sense the free charges in the environment and adsorb them on the surface, forming a piezoelectric effect.

4. The method for preparing a muscle patch with strong elasticity, self-powered and capable of monitoring human motion signals according to claim 3, characterized in that: The mass ratio of the high molecular polymer Ecoflex to anhydrous ethanol in step (2) is 50:

1.

5. The method for preparing a muscle patch with strong elasticity, self-powered and capable of monitoring human motion signals according to claim 3, characterized in that: The speed of the mixer in step (2) is 3000 rpm.

6. The method for using the muscle patch with strong elasticity, self-power supply and capable of monitoring human motion signals according to claim 1, characterized in that: The muscle patch is worn on the surface of human skin that needs to be detected during exercise. Two wires are connected to the surface electrode through carbon conductive glue, and the other end of the wire is connected to the microprocessor. When the human body starts to exercise, the muscle patch starts to collect motion signals, and the signals are transmitted to the microprocessor through the wires. After being processed by the microprocessor, the signals are displayed on the monitor.

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