A skin friction nano-power generation sensor and method for human motion intention recognition

Abstract

The present invention belongs to the technical field related to human motion monitoring and intention recognition. It discloses a skin friction nano-power generation sensor and method for human motion intention recognition. The sensor is a flexible and stretchable structure, comprising a cavity cover, an upper friction layer, a lower friction layer, an encapsulation layer, an electrode layer, a substrate, and an adhesion layer. The lower friction layer, the encapsulation layer, the electrode layer, the substrate, and the adhesion layer are stacked from top to bottom. The cavity cover is cylindrical, with a receiving groove at one end. The upper and lower friction layers are both located within the receiving groove, and the upper friction layer is disposed on the bottom surface of the receiving groove. The open end of the receiving groove is disposed on the encapsulation layer, and the groove wall of the receiving groove is a hollow structure. The present invention enhances the voltage signal output, effectively improving the minimum detection strain and sensitivity of the sensor.

Description

Technical Field

[0001] The present invention belongs to the technical field related to human motion monitoring and intention recognition, and more specifically, relates to an epidermal friction nano-power generation sensor and method for human motion intention recognition. Background Art

[0002] With the advancement of technology, smart devices are becoming increasingly integrated into people's daily lives. Their increasingly powerful capabilities also come with increasingly complex operations, leading to a growing emphasis on the development and improvement of human-computer interaction systems. Traditional human-computer interaction is often complex, requiring people to adapt to the devices, which can be challenging to learn. Furthermore, the information provided by the interactions is increasingly difficult to adapt to the demands of more intelligent operations. To address these issues, wearable devices are being used to collect signals such as human posture and movement, providing richer control information and further improving the dexterity and stability of interactions.

[0003] Most existing wearable devices are shaped like gloves, bracelets, or armbands, similar to clothing. Their comfort needs to be improved, and they also restrict the normal movement of the human hand and arm, distorting the collected signals and limiting the development of natural and refined human-computer interaction. Therefore, if a new type of wearable epidermal sensor could be designed that can be directly attached to the skin without the need for auxiliary equipment such as tape or bandages, thereby removing the restrictions on normal arm and hand movement, it would further promote the development of comfortable and natural human-computer interaction systems and their application in daily life. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvements in the existing technology, the present invention provides a sensor and method for identifying human motion intentions using a triboelectric nanoelectricity sensor. The sensor senses muscle deformation during hand movements and converts it into electrical signals. The greater the muscle deformation, the higher the sensor's output voltage, which is then used to identify human motion intentions. Furthermore, the sensor is thin and can be attached directly to the arm like skin, virtually ignoring human motion. This improves the wearability and comfort of the device while ensuring the naturalness and authenticity of the collected signals, thereby improving the recognition rate of human motion intentions.

[0005] To achieve the above-mentioned objectives, according to one aspect of the present invention, a skin friction nano-power generation sensor for identifying human motion intention is provided. The sensor is a flexible and stretchable structure, which includes a cavity cover, an upper friction layer, a lower friction layer, a packaging layer, an electrode layer, a substrate and an adhesion layer. The lower friction layer, the packaging layer, the electrode layer, the substrate and the adhesion layer are stacked from top to bottom; the cavity cover is cylindrical, and a receiving groove is opened at one end thereof. The upper friction layer and the lower friction layer are both located in the receiving groove, and the upper friction layer is arranged on the bottom surface of the receiving groove; the open end of the receiving groove is arranged on the packaging layer, and the groove wall of the receiving groove is a hollow structure.

[0006] Furthermore, a separable contact is formed between the upper friction layer and the lower friction layer.

[0007] Furthermore, the modulus of the material of the upper friction layer is greater than the modulus of the material of the lower friction layer.

[0008] Furthermore, the material of the packaging layer is consistent with the material of the cavity cover.

[0009] Furthermore, the sensor is in the form of a thin film, the packaging layer, the electrode layer, the substrate and the adhesion layer are square, and the side length is 5 to 10 mm larger than the diameter of the upper friction layer and the lower friction layer; the thickness of the sensor is 200 to 600 microns.

[0010] Furthermore, the cavity cover, the packaging layer, and the substrate are made of flexible and stretchable materials; the upper friction layer is made of a positive polarity friction electrode sequence material; and the lower friction layer is made of a negative polarity friction electrode sequence material.

[0011] Furthermore, the sensor is conformally attached to human skin via an adhesive layer, and can deform synchronously with the human skin.

[0012] The present invention also provides a method for identifying human body movement intention, the method comprising the following steps:

[0013] (1) The above-mentioned skin friction nano-power generation sensor for human motion intention recognition is attached to the muscle part of the human forearm to collect multi-channel signals of various human gestures;

[0014] (2) Extract signal features and use classification algorithms for training to establish corresponding training recognition models;

[0015] (3) Use the trained recognition model to identify and classify the new multi-channel signals to determine the correct human gesture intention.

[0016] Furthermore, the number of the sensors is 4 to 8.

[0017] In general, compared with the prior art, the above technical solutions conceived by the present invention have the following beneficial effects:

[0018] 1. The sensor provided by the present invention is a wearable epidermal sensor made of a flexible, stretchable material in the form of a thin film. The modulus of the base and adhesive layer is similar to that of human skin, allowing for precise adhesion to the skin without the need for bandages, tape, or other auxiliary fixation. It does not interfere with the normal movement of the human hand and arm and is virtually unnoticeable. The sensor provided by the present invention is stretchable and can conformally adhere to the skin and deform synchronously, providing improved wearability and comfort, thereby ensuring the collection of natural and authentic muscle movement signals.

[0019] 2. The upper friction layer is made of a material with a larger modulus, while the lower friction layer is made of a material with a smaller modulus. This ensures that when the sensor is subjected to external force, the deformation of the lower friction layer is large, while the deformation of the upper friction layer is small. This makes the contact and separation effect between the two more obvious, enhances the voltage signal output, and effectively improves the minimum detection strain and sensitivity of the sensor.

[0020] 3. The groove wall of the cavity cover adopts a hollow design. This not only improves the elasticity of the groove wall, making it easier to deform; on the other hand, it also facilitates the discharge of gas in the receiving groove without affecting the deformation of the receiving groove.

[0021] 4. The sensors of the present invention are arranged at multiple muscle positions related to human gesture movements. They have large deformation when gestures are working, which in turn leads to an increase in the effective contact area between the upper and lower friction layers and an increase in the transferred charge. Therefore, they have a higher output and can better distinguish different gestures.

[0022] 5. The sensor provided by the present invention has two friction layers, upper and lower. The materials of the two friction layers are stable and are basically not affected by environmental changes, ensuring the uniformity of the device and the consistency of the output signal.

[0023] 6. The electrode layer of the sensor is completely encapsulated and will not fail due to oxidation. Compared with other sensors, it has excellent durability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a skin friction nano-power generation sensor for human motion intention recognition provided by the present invention;

[0025] Figure 2 yes Figure 1 Schematic diagram of the cavity cover of the epidermal friction nano-power generation sensor for human motion intention recognition;

[0026] Figure 3abcd in Figure 1 Schematic diagram of the working principle of the epidermal friction nano-power generation sensor for human motion intention recognition when it is subjected to pressure;

[0027] Figure 4 abcd in Figure 1 Schematic diagram of the working principle of the epidermal friction nano-power generation sensor for human motion intention recognition when subjected to stretching deformation;

[0028] Figure 5 yes Figure 1 The signal diagram of the epidermal friction nano-power generation sensor for human motion intention recognition changes with external pressure;

[0029] Figure 6 Figure 1 Single channel signal diagram of the epidermal friction nanopower generation sensor for human motion intention recognition as the human body moves.

[0030] In all drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1 - cavity cover, 2 - upper friction layer, 3 - lower friction layer, 4 - packaging layer, 5 - electrode layer, 6 - substrate, 7 - adhesion layer. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0032] See also Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The present invention provides an epidermal friction nano-power generation sensor for human motion intention recognition. The sensor is used for muscle motion measurement and human motion intention recognition. A plurality of the sensors are placed on the muscle positions on the human forearm that are related to gesture movements, and the human body's motion intention can be effectively recognized. Among them, by collecting multi-channel induced voltage signals of different gesture movements and using a classification algorithm to establish a corresponding classification model, the corresponding gesture movement type is identified. The present invention transfers the sensor from the human hand to the specific forearm muscle of the human body, removing the restriction on the normal movement of the human hand. At the same time, by adding an adhesive layer, the device is more closely attached to the arm muscle, is basically not perceived by the human body, and remains stable during movement, which greatly improves the wearability, comfort and practicality of the human motion intention recognition sensor.

[0033] The sensor includes a cavity cover 1, an upper friction layer 2, a lower friction layer 3, an encapsulation layer 4, an electrode layer 5, a substrate 6, and an adhesion layer 7. The substrate 6 is disposed on the adhesion layer 7, the electrode layer 5 is disposed on the substrate 6, and the encapsulation layer 4 is disposed on the electrode layer 5. The lower friction layer 3 is disposed on the encapsulation layer 4 and is located within a receiving groove formed by the cavity cover 1. The open end of the receiving groove is disposed on the encapsulation layer 4. The upper friction layer 2 is disposed on the bottom surface of the receiving groove and is in detachable contact with the lower friction layer. When the sensor is not in operation, the upper friction layer 2 and the lower friction layer 3 are spaced apart.

[0034] The groove wall of the receiving groove is a hollow structure. On the one hand, this improves the elasticity of the groove wall and makes it easier to deform; on the other hand, it also facilitates the discharge of gas in the receiving groove without affecting the deformation of the receiving groove. In this embodiment, the cavity cover 1 is basically cylindrical, which includes a circular cover plate and a plurality of arc-shaped protrusions arranged at one end on the circumferential edge of the cover plate. The other end of the arc-shaped protrusion is tightly attached to the packaging layer through van der Waals force. The two can also be attached before the packaging layer 4 is cured, and they can be combined more tightly after curing. Among them, the plurality of arc-shaped protrusions are evenly spaced around the central axis of the cover plate to form the cylindrical receiving groove; the cover plate and the arc-shaped protrusions are integrally molded from a flexible polymer material.

[0035] The modulus of the material of the upper friction layer 2 is much greater than the modulus of the material of the lower friction layer 3, and the modulus of the two materials is quite different. The material of the encapsulation layer 4 is consistent with the material of the cavity cover 1. The modulus of the material of the lower friction layer 3, the material of the encapsulation layer 4, the material of the substrate 6 and the material of the adhesion layer 7 are all relatively small.

[0036] The muscles on the human forearm that are related to gesture movements refer to the hand muscles that produce more obvious deformation and larger changes in amplitude when the human body gestures. There are 19 muscles in the human forearm, distributed on the front and back sides, arranged in layers, and overlapping with each other. The anterior group of muscles is located on the front of the forearm and is mainly composed of flexor muscles, which are responsible for the flexion of the wrist, elbow and fingers; while the posterior group of muscles is located on the back of the forearm and is mainly composed of extensor muscles, which are responsible for the extension of various joints. The pronation and supination movements of the arm rely on the pronator dorsi and supinator muscles of the forearm. The flexion and extension movements of the thumb are respectively controlled by separate muscles in the forearm; while the flexion of the index finger, middle finger, ring finger and little finger relies on the superficial flexor digitorum or the deep flexor digitorum, and extension relies on the extensor digitorum communis. This embodiment selects the relevant muscles according to the selected gesture movement to achieve higher sensing performance. The muscles related to gesture movements are selected from the flexor pollicis longus, flexor digitorum profundus, flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum minimi, extensor digitorum, abductor pollicis longus, extensor index finger, extensor pollicis brevis, extensor pollicis longus, pronator teres, and supinator.

[0037] The cavity cover 1, encapsulation layer 4, and substrate 6 are made of insulating, flexible, and stretchable materials. The electrode layer 5 is made of a conductive material. The upper friction layer 2 is made of a positive triboelectric material with a large modulus; the lower friction layer 3 is made of a negative triboelectric material with a small modulus. The adhesion layer 7 is made of a viscous material. The conductive material is selected from stretchable conductive materials such as silver nanowires, conductive hydrogels, carbon nanotubes, PEDOT:PSS, and polypyrrole. The insulating, flexible, and stretchable material is selected from rubber, polydimethylsiloxane (PDMS), platinum-catalyzed silicone rubber, Ecoflex, polyurethane (PU), thermoplastic polyurethane (TPU), styrene-butadiene-styrene block copolymer (SBS), and styrene-ethylene-butylene-styrene block copolymer (SEBS).

[0038] The positive triboelectrode sequence material with a larger modulus is selected from polyvinyl acetate, ethyl cellulose, nylon-66, paper, aluminum foil, copper foil, nickel foil, and polyvinyl alcohol. The negative triboelectrode sequence material with a smaller modulus is selected from polystyrene, polyethylene, polypropylene, polydiphenylpropane carbonate, polyethylene terephthalate, polyimide, polyvinyl chloride, polydimethylsiloxane, polychlorotrifluoroethylene, and polytetrafluoroethylene. The adhesive material is selected from adhesive polydimethylsiloxane, double-sided tape, and adhesive hydrogel.

[0039] Each sensor's cavity cover 1, upper friction layer 2, and lower friction layer 3 are all circular. The inner diameter of the cavity cover 1 is the same as the diameters of the upper and lower friction layers 2 and 3, ranging from 8 to 12 mm. The wall thickness of the cavity cover 1 is 0.5 to 1.5 mm, resulting in an outer diameter of the cavity cover 1 that is 1 to 3 mm larger than the inner diameter. The encapsulation layer 4, electrode layer 5, substrate 6, and adhesion layer 7 are square, with side lengths 5 to 10 mm larger than the diameters of the upper and lower friction layers. The geometric centers of these layers lie on the same axis. The combined thickness of the cavity cover 1 and upper friction layer 2 is 50 to 100 microns, with a groove height of 100 to 400 microns. The combined thickness of the adhesion layer 7, substrate 6, encapsulation layer 4, and lower friction layer 3 is 50 to 100 microns, resulting in an overall sensor thickness of 200 to 600 microns.

[0040] The sensor adheres tightly to human skin via an adhesive layer 7. When the hand moves, muscle movement causes skin deformation, which in turn causes deformation of the sensor. This changes the volume of the receiving groove, leading to friction and surface charge transfer between the upper and lower friction layers 2 and 3, generating a voltage signal. This signal is then output through the electrode layer 5. The greater the amplitude of the human movement, the more intense the skin deformation, and the larger the triboelectric signal generated by the sensor. The lower friction layer 3, encapsulation layer 4, electrode layer 5, substrate 6, and adhesive layer 7 exhibit large deformation due to their thinness and low modulus. However, the cavity cover 1 and upper friction layer 2 exhibit smaller deformation due to their larger modulus. This further causes the upper and lower friction layers of the device to contact and separate, generating friction. Simultaneously, the friction area changes depending on the magnitude and direction of the force applied to the upper and lower friction layers caused by different hand movements. This voltage signal, which varies with hand movement, is then output to the external circuit via the electrode layer 5, enabling muscle movement measurement and intention recognition.

[0041] The present invention also provides a method for recognizing human motion intentions, comprising the following steps: S1: attaching 4 to 8 epidermal sensors to the muscles of the human forearm to collect multi-channel signals of various human gestures; S2: extracting signal features and training them using a classification algorithm to establish a corresponding training recognition model; S3: using the established model to identify and classify the new multi-channel signals to determine the correct human gesture intention. A single sensor can perform gesture recognition, but the recognition rate and number of recognized types will be reduced. The number of sensors can be determined based on actual needs. Using 8 channels, 26 gestures were recognized with an average recognition rate exceeding 95%. Fewer channels result in a lower recognition rate.

[0042] The sensor is attached to the skin of the human forearm muscle. When the human hand moves, the muscle at the sensor location is deformed, and the sensor is acted upon by force, causing the upper and lower friction layers to come into contact and separate. This can form a voltage signal output in the electrode. Different gestures have different muscle deformation amplitudes at different locations, so the epidermal sensor is subjected to different forces and signal amplitudes. Therefore, the size of muscle movement signals at different locations can be used to identify the human gesture and determine the human intention.

[0043] See also Figure 3 and Figure 4 When the sensor is attached to the muscle belly, the muscle belly bulges when the muscle contracts, and the sensor is approximately subjected to pressure; when the sensor is attached to the tendon, the tendon relaxes when the muscle relaxes, and the sensor is approximately subjected to tensile deformation.

[0044] When the device is attached to the muscle belly, Figure 3 a in the figure is the state of the device when the muscle is relaxed, and the upper friction layer 2 and the lower friction layer 3 are separated. When the muscle contracts, the muscle belly expands, pressing the sensor so that the receiving groove shrinks, and the upper friction layer 2 and the lower friction layer 3 are brought closer, as shown in FIG. Figure 3 As shown in b in the figure. At this time, the induced charge in the electrode layer 5 decreases, and the external free electrons flow in, and the generated voltage signal decreases. When the muscle contracts to the limit, the receiving groove is compressed to the minimum, and the voltage is also reduced to the lowest, as shown in Figure 3 As shown in c in the figure. Then the muscle begins to relax, the muscle belly shrinks, the pressure on the sensor decreases, the receiving groove expands, and the upper friction layer 2 and the lower friction layer 3 move away from each other, as shown in the figure. Figure 3 As shown in d in the figure. At this time, the induced charge in the electrode layer 5 increases, free electrons flow out, and the generated voltage signal increases. When the muscle is completely relaxed, the receiving groove also returns to Figure 3 The voltage returns to the initial position shown in a, completing a cycle.

[0045] Figure 4 In a to d, the device is attached to the tendon. Figure 4 a in the figure is the state of the device when the muscle is relaxed, and the upper friction layer 2 and the lower friction layer 3 are separated. When the muscle relaxes, the tendon relaxes, causing the sensor to be stretched and deformed, and the receiving groove deforms accordingly, so that the upper friction layer 2 and the lower friction layer 3 are close together, as shown in the figure. Figure 4 As shown in b in the figure. At this time, the induced charge in the electrode layer 5 decreases, and the external free electrons flow in, and the generated voltage signal decreases. When the muscle is stretched to the limit, the receiving groove is deformed to the maximum, the distance between the upper friction layer 2 and the lower friction layer 3 becomes the minimum, and the voltage is reduced to the lowest, as shown in Figure 4 As shown in c in the figure. Then the muscle begins to contract, and the tendon contracts accordingly, the tensile deformation of the sensor is reduced, the receiving groove is restored, and the upper friction layer 2 and the lower friction layer 3 are also separated, as shown in Figure 4As shown in d in the figure. At this time, the induced charge in the electrode layer 5 increases, free electrons flow out, and the generated voltage signal increases. When the muscle is completely relaxed, the receiving groove also returns to Figure 4 The voltage returns to the initial position shown in a, completing a cycle.

[0046] Figure 5 This diagram shows the signal of the wearable epidermal sensor proposed in the present invention as it changes with external pressure. When external pressure is applied to the wearable epidermal sensor, it generates an electrical signal. When the external pressure is removed, the signal returns to its resting potential, demonstrating the sensor's excellent sensing performance for external pressure.

[0047] Figure 6 This is a single-channel signal diagram of a wearable epidermal sensor for human intention recognition according to the present invention, as it moves with the body. When the hand moves, muscle deformation generates force on the wearable epidermal sensor, which generates an electrical signal. When the hand relaxes, the signal returns to its resting potential, enabling the wearable epidermal sensor to detect the start and end points, amplitude, and duration of human movement.

[0048] The present invention is further described in detail below with reference to several specific embodiments.

[0049] Example 1:

[0050] This embodiment uses Figure 1 The wearable epidermal sensor configuration shown in Figure 1 is constructed from Ecoflex. The electrode layer 5 is made of silver nanowires (AgNWs) sprayed onto the substrate 6. The adhesion layer 7 is made of viscous polydimethylsiloxane. The cavity cover 1 and the encapsulation layer 4 are both made of polydimethylsiloxane (PDMS). The upper friction layer 2 is made of polyvinyl acetate (PVAc), and the lower friction layer 3 is made of polytetrafluoroethylene (PTFE). Van der Waals forces tightly bond the upper friction layer 2 to the cavity cover 1, and the lower friction layer 3 to the encapsulation layer 4. The substrate 6 has a side length of 18 cm, the upper friction layer 2 has a diameter of 10 cm, the groove wall thickness is 1 mm, and the initial (unstressed) height of the receiving groove is 0.3 mm.

[0051] Eight sensors are attached to the skin corresponding to the muscles of the human forearm. When the hand moves, the muscles drive the skin, further deforming the sensor's receiving groove. This causes the upper friction layer 2 and lower friction layer 3 to contact and separate, leading to surface charge transfer and generating induced charge on the electrode layer 5. The silver nanowire film on the electrode layer 5 is connected to the analog-to-digital acquisition card via wires. One wire leads from each sensor, collecting a total of eight channels of signal. As the hand gesture posture and amplitude change, the induced charge on the electrode layer 5 changes, and the voltage signal collected by the acquisition card also changes accordingly. Features from the eight-channel signals are extracted and trained using a support vector machine (SVM) classification algorithm to establish a corresponding training recognition model. Finally, this model is used to identify and classify the new multi-channel signals to determine the correct human gesture intention.

[0052] Example 2:

[0053] This embodiment uses Figure 1 The configuration of the wearable epidermal sensor shown in the figure. The substrate 6 is made of polydimethylsiloxane (PDMS) with a low curing agent ratio, the electrode layer 5 is made of carbon nanotubes and is sprayed on the substrate 6, the adhesion layer 7 is made of double-sided tape, the cavity cover 1 and the packaging layer 4 are both made of polydimethylsiloxane (PDMS) with a normal ratio, the upper friction layer 2 is made of aluminum foil, and the lower friction layer 3 is made of polydimethylsiloxane. The upper friction layer 2 and the cavity cover 1, and the lower friction layer 3 and the packaging layer 4 are tightly bonded by van der Waals forces. The side length of the substrate 6 is 15 cm, the diameter of the upper friction layer 2 is 8 cm, the groove wall thickness is 1 mm, and the height of the receiving groove in the initial state (no force) is 0.3 mm.

[0054] Eight sensors are attached to the skin corresponding to the muscles of the human forearm. When the hand moves, the muscles drive the skin, further deforming the sensor's receiving groove. This causes the upper friction layer 2 and lower friction layer 3 to separate and contact, leading to surface charge transfer and generating induced charge on the electrode layer 5. The carbon nanotube film on the electrode layer 5 is connected to the analog-to-digital acquisition card via wires. Each sensor leads to one wire, collecting a total of eight channels of signal. As the hand gesture posture and amplitude change, the induced charge on the electrode layer 5 changes, and the voltage signal collected by the acquisition card also changes accordingly. Features of the eight-channel signals are extracted and trained using the linear discriminant analysis (LDA) classification algorithm to establish a corresponding training recognition model. Finally, this model is used to identify and classify the new multi-channel signals to determine the correct human gesture intention.

[0055] Example 3:

[0056] This embodiment uses Figure 1The wearable epidermal sensor configuration shown in Figure 1 is constructed from polydimethylsiloxane (PDMS) with a low curing agent ratio. The electrode layer 5 is made of PEDOT:PSS, sprayed onto the substrate 6. The adhesion layer 7 is a viscous hydrogel. The cavity cover 1 and the encapsulation layer 4 are both made of Ecoflex. The upper friction layer 2 is made of nylon-66, and the lower friction layer 3 is made of polytetrafluoroethylene (PTFE). The upper friction layer 2 and the cavity cover 1, as well as the lower friction layer 3 and the encapsulation layer 4, are tightly bonded by van der Waals forces. The substrate 6 has a side length of 16 cm, the upper friction layer 2 has a diameter of 10 cm, the groove wall thickness is 0.5 mm, and the initial (unstressed) height of the receiving groove is 0.3 mm.

[0057] Eight sensors are attached to the skin corresponding to the muscles of the human forearm. When the hand moves, the muscles drive the skin, further deforming the sensor's receiving groove. This causes the upper friction layer 2 and lower friction layer 3 to separate, leading to surface charge transfer and generating induced charge on the electrode layer 5. The PEDOT:PSS film in electrode layer 5 is connected to an analog-to-digital acquisition card via wires. One wire leads from each sensor, collecting a total of eight channels of signal. As the hand gesture posture and amplitude change, the induced charge on electrode layer 5 changes, and the voltage signal collected by the acquisition card also changes accordingly. Features from the eight-channel signals are extracted and trained using the K-nearest neighbor classification algorithm to establish a corresponding training recognition model. Finally, this model is used to identify and classify the new multi-channel signals to determine the correct human gesture intention.

[0058] The wearable epidermal sensor of the present invention is mainly used for human motion intention recognition, such as measuring human gestures, movement amplitude, duration, etc. It can serve as a good supplement in the field of human-computer interaction and has great application value and broad development prospects.

[0059] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A skin friction nano-power generation sensor for human motion intention recognition, characterized by: The sensor is a flexible and stretchable structure, comprising a cavity cover, an upper friction layer, a lower friction layer, an encapsulation layer, an electrode layer, a substrate, and an adhesion layer, wherein the lower friction layer, the encapsulation layer, the electrode layer, the substrate, and the adhesion layer are stacked from top to bottom; the cavity cover is cylindrical, with a receiving groove formed at one end, the upper friction layer and the lower friction layer both being located within the receiving groove, and the upper friction layer being disposed on the bottom surface of the receiving groove; the open end of the receiving groove is disposed on the encapsulation layer, and the groove wall of the receiving groove is a hollow structure; The upper friction layer and the lower friction layer form a separable contact.

2. The skin friction nano-power generation sensor for human motion intention recognition according to claim 1, characterized in that: The modulus of the material of the upper friction layer is greater than the modulus of the material of the lower friction layer.

3. The skin friction nano-power generation sensor for human motion intention recognition according to claim 2, characterized in that: The material of the packaging layer is consistent with the material of the cavity cover.

4. The epidermal friction nano-power generation sensor for human motion intention recognition according to any one of claims 1 to 3, characterized in that: The sensor is in the form of a thin film. The packaging layer, the electrode layer, the substrate and the adhesion layer are square, and the side length is 5 to 10 mm larger than the diameter of the upper friction layer and the lower friction layer. The thickness of the sensor is 200 to 600 microns.

5. The epidermal friction nano-power generation sensor for human motion intention recognition according to any one of claims 1 to 3, characterized in that: The cavity cover, the packaging layer, and the substrate are made of flexible and stretchable materials; the upper friction layer is made of a positive-polarity friction electrode sequence material; and the lower friction layer is made of a negative-polarity friction electrode sequence material.

6. The epidermal friction nano-power generation sensor for human motion intention recognition according to any one of claims 1 to 3, characterized in that: The sensor is conformally attached to human skin via an adhesive layer and can deform synchronously with the human skin.

7. A method for identifying human motion intention, characterized in that: The method comprises the following steps: (1) The skin friction nano-power generation sensor for human motion intention recognition according to any one of claims 1 to 6 is attached to the muscle part of the human forearm to collect multi-channel signals of various human gestures; (2) Extract signal features and use classification algorithms for training to establish corresponding training recognition models; (3) Use the trained recognition model to identify and classify the new multi-channel signals to determine the correct human gesture intention.

8. The method for recognizing human body movement intention according to claim 7, wherein: The number of the sensors is 4 to 8.

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