Hand bionic nerve high-density array flexible electrode for tactile feedback

Abstract

The hand bionics nerve high-density array type flexible electrode for tactile feedback belongs to the field of electric stimulation, and aims at solving the problems of the existing tactile feedback system.The hand bionics nerve high-density array type flexible electrode for tactile feedback comprises a flexible bottom layer and a high-density electrode matrix, and the high-density electrode matrix is prepared on the flexible bottom layer; the flexible bottom layer is shaped like a hand and is divided into a palm area and a finger area; the high-density electrode matrix comprises a plurality of electrode net units, the plurality of electrode net units are distributed in the palm area and the finger area, and local electric stimulation on different areas is realized by controlling the current of different areas.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrode structure for electrical stimulation, belonging to the field of electrical stimulation. BACKGROUND

[0002] In recent years, with the rapid development of virtual reality (VR), augmented reality (AR) and robotic bionics technology, haptic feedback technology has received widespread attention. Traditional haptic feedback devices mostly rely on single haptic feedback methods such as vibration motors and piezoelectric devices, and are mainly used to simulate the hardness, vibration and touch of objects. However, this kind of technology still has many deficiencies in application, especially in the field of delicate haptics and complex motion control. The following are the main levels of existing haptic feedback technology and the problems existing in it:

[0003] Existing haptic feedback systems can be roughly divided into the following categories:

[0004] 1. Vibration feedback system: uses vibration motors to simulate haptics, widely used in mobile phones, game controllers and other devices. However, vibration feedback can only provide rough haptic information such as tapping, shaking, etc., and cannot accurately simulate the texture, shape or complex force feedback of objects.

[0005] 2. Piezoelectric feedback system: provides haptic feedback through the deformation of piezoelectric materials, which can provide relatively accurate haptic signals and is suitable for small-scale feedback such as touch screen devices. However, its physical structure limits the feedback area and complexity, making it difficult to cover a larger area of the hand.

[0006] 3. Mechanical feedback device: provides physical force feedback through external mechanical structures such as force feedback gloves or exoskeleton systems. Although this type of device can simulate more realistic force feedback, it is usually bulky and inconvenient to wear, making it difficult to achieve flexible and widespread daily applications, especially in complex virtual environment interactions.

[0007] Defects of existing technologies, although existing haptic feedback technologies have achieved preliminary success in some application scenarios, there are still obvious limitations in the following aspects:

[0008] 1. Limited coverage: Most haptic feedback devices can only focus on a small area of the palm or fingers, making it difficult to achieve fine haptic feedback for the entire hand. Delicate haptic experiences for the hand rely on large-area, multi-point electrode coverage, and existing systems usually cannot provide consistent feedback effects throughout the palm and finger area.

[0009] 2. Insufficient feedback accuracy: Existing vibration or piezoelectric feedback devices often lack the necessary precision and detail when simulating fine haptics, such as surface textures or object shapes. Especially when complex tactile changes or force feedback need to be simulated, the response capabilities of these devices are insufficient, and they cannot provide realistic haptic perception to the user.

[0010] 3. Poor dynamic adaptability: Many existing haptic feedback systems significantly degrade in response when the hand moves or changes posture. In particular, at the joints of the fingers, it is difficult to ensure high-quality electrical stimulation due to poor contact of electrodes or sensors. This problem greatly affects user experience in daily applications, especially in virtual reality applications that require flexible hand movements, and cannot provide continuous and accurate haptic feedback.

[0011] 4. Bulky and inconvenient devices: Although mechanical force feedback devices can simulate certain realistic haptics, they are too large and complex in structure to be worn comfortably and are not suitable for long-term use or high-mobility scenarios. At the same time, external mechanical force feedback cannot simulate subtle haptic perception and cannot provide detailed feedback based on neuromuscular control.

[0012] 5. Insufficient real-time feedback: Some existing haptic feedback devices have slow response speeds, especially in complex interactive environments, making it difficult to achieve real-time dynamic adjustment of haptic feedback. This limits the user's immersive experience in fast interactions and prevents them from realistically perceiving subtle changes in objects or environments.

[0013] In summary, due to the above deficiencies in existing technology, haptic feedback devices are difficult to meet the following needs in practical applications:

[0014] 1. Full-coverage fine haptic feedback for the hand: Existing technology cannot achieve full-coverage, multi-point precise electrical stimulation feedback for the hand, especially in complex parts of the fingers and palms, and cannot provide flexible and continuous haptic information.

[0015] 2. High-precision haptic perception and force feedback: Existing devices are insufficient in force transmission and fine haptic simulation, and cannot meet the needs of applications that require high-precision feedback, such as bionic hands, fine object manipulation, etc.

[0016] 3. Stable electrode contact for dynamic hand movement: Existing electrode systems are prone to poor contact and feedback signal attenuation during dynamic hand movement, and cannot guarantee continuous haptic feedback.

[0017] 4. Lightweight and portable design: Traditional force feedback gloves and mechanical devices are still too bulky in design and cannot meet the needs of portability and daily use, especially for long-term wear experience. SUMMARY

[0018] In view of the problems existing in the prior art haptic feedback system, the application provides a hand bionic nerve high-density array flexible electrode for haptic feedback. The high-density array flexible electrode system, combined with hand nerve bionic technology and full coverage design, can provide dynamic haptic feedback for the whole hand. This design ensures high-precision haptic simulation and dynamic adaptability while maintaining lightweight and portability, and solves the defects of the prior art haptic feedback system in coverage, feedback accuracy, motion adaptability and wearing comfort.

[0019] The hand bionic nerve high-density array flexible electrode for haptic feedback comprises a flexible bottom layer 100 and a high-density electrode matrix, and the high-density electrode matrix is prepared on the flexible bottom layer 100.

[0020] The flexible bottom layer 100 is in the shape of a hand and is divided into a palm area and a finger area; the high-density electrode matrix comprises a plurality of electrode mesh units, the plurality of electrode mesh units are distributed in the palm area and the finger area, and local electric stimulation of different areas is realized by controlling the current of different areas.

[0021] Preferably, the palm area comprises a heel region, a thenar region and a hypothenar region; and the finger area comprises a knuckle region and a finger pad region.

[0022] Preferably, the high-density electrode matrix is constructed by N button contact electrodes, the button contact electrode is composed of an outer electrode A and an inner electrode B, the outer electrode A is a ring structure with a notch, the notch is 1 / 4 to 1 / 3 of the whole ring, the inner electrode B is a round sheet electrode, and the outer electrode A is concentrically surrounded outside the inner electrode B.

[0023] The N outer electrodes A are connected to a first N-channel control terminal CON1, the N inner electrodes B are connected to a second N-channel control terminal CON2, and the first N-channel control terminal CON1 and the second N-channel control terminal CON2 are respectively connected to two ends of a direct current power supply, so that a potential difference is formed between the outer electrode A and the inner electrode B of each button contact to realize electric stimulation of the point.

[0024] Preferably, the first N-channel control terminal CON1 and the second N-channel control terminal CON2 are respectively connected to the positive and negative poles or the negative and positive poles of the direct current power supply.

[0025] Preferably, the switches of each channel of the first N-channel control terminal CON1 and the second N-channel control terminal CON2 are independently controlled to realize electric stimulation of any area alone.

[0026] Preferably, the flexible bottom layer 100 is a flexible printed circuit board (FPC) made of a flexible insulating substrate, specifically including a hydrogel layer 101, a PI layer 102, a copper foil layer 103, and a non-woven fabric layer 104, the non-woven fabric layer 104 is prepared with the PI layer 102, the button contact electrodes are prepared on the PI layer 102 using the copper foil layer 103, and are pasted on the human skin through the hydrogel layer 101.

[0027] Preferably, a plurality of fixing holes are further included for winding and wearing the arrayed flexible electrode on the hand.

[0028] Preferably, N = 16 ~ 256.

[0029] Preferably, each knuckle area contains at least 4 pairs of button contact electrodes, and each knuckle area contains at least 9 pairs of button contact electrodes.

[0030] The present application has the following advantages: The present application provides a haptic feedback glove system based on high-density flexible electrodes, effectively solving the problems of limited coverage, insufficient feedback accuracy, poor dynamic adaptability, and bulky equipment in the prior art, with significant technical advantages and innovative points, specifically in the following aspects:

[0031] 1. Full-hand coverage of high-density haptic feedback

[0032] The electrode system of the present application contains 193 electrodes distributed in the palm, fingers and joint areas, forming a full-hand high-density haptic feedback network. Compared with the design in the prior art which can only cover local areas, the present application can provide fine and uniform electrical stimulation throughout the hand, thereby realizing full-coverage haptic feedback experience of the hand. Through precise control of multiple point electrodes, users can perceive subtle haptic changes in different parts, such as texture, pressure and force feedback, which is particularly outstanding in virtual reality applications.

[0033] 2. High-precision, adjustable electrical stimulation parameters

[0034] The present application realizes fine adjustment of various haptic feedback through precise electrical stimulation control, which is significantly superior to the haptic feedback devices in the prior art. The main performance indicators of the electrical stimulation system are as follows:

[0035] · Current range: 0 ~ 65.536 mA, with a minimum resolution of 0.256 mA, which can provide highly adjustable current intensity according to different haptic needs. Smaller resolution allows more fine-grained electrical stimulation control, ensuring comfort and feedback accuracy in different haptic simulation scenarios.

[0036] • Frequency range: 1-255 Hz, allowing flexible adjustment of the electrical stimulation frequency to adapt to different application scenarios. For example, in high-frequency cases, the system can simulate vibrations and surface roughness; in low-frequency cases, it can provide more realistic force sensation and pressure feedback.

[0037] • Pulse width range: 0-510 μs, allowing the electrodes to conduct current at different pulse widths to simulate different types of nerve stimulation or haptic feedback. This range allows precise control of the activation time of each electrode, providing fine haptic perception.

[0038] 3. Dynamic adaptability and electrode contact stability

[0039] The present invention uses flexible electrode materials and high-density array design to ensure that the electrodes can maintain good contact during dynamic hand movement, avoiding the signal attenuation problem caused by poor electrode contact in the prior art. The flexible substrate can conform to the hand curve, maintaining the stability of the electrodes even in complex hand movements (such as gripping, finger joint bending), ensuring continuous electrical stimulation effect. Through cooperation with the control module, the system can adjust the electrical stimulation parameters in real time, achieving dynamic adaptation and feedback adjustment of different areas of the hand.

[0040] 4. Closed-loop control and personalized adjustment

[0041] The present invention has a closed-loop feedback control system that can dynamically adjust electrical stimulation parameters based on sensor feedback of hand movements or muscle signals, ensuring the real-time and effectiveness of haptic feedback. Compared with the prior art that cannot adjust the intensity and frequency of electrical stimulation in real time, the present system can provide personalized haptic experience in virtual reality, augmented reality, and rehabilitation training. For example, the system can automatically adjust the intensity of haptic feedback according to the user's grip strength, allowing the user to feel the hardness and surface characteristics of different objects.

[0042] 5. Lightweight design and portability

[0043] Compared with existing mechanical force feedback devices, the flexible electrode system of the present invention uses lightweight materials, providing good wearing comfort. Since the system eliminates complex mechanical structures, it significantly reduces the weight of the device, allowing users to wear it for a long time and making it suitable for portable applications, especially in scenarios with high mobility requirements, such as virtual reality games, remote control, and bionic hand operation.

[0044] 6. Fine haptic simulation

[0045] The application can realize fine haptic feedback according to different application requirements, covering from weak surface vibration perception to strong force feedback. Especially in bionic hand, virtual reality haptic interaction and rehabilitation training, the system can perceive various subtle haptic changes in the environment according to the real-time operation of the user, including surface texture, hardness and shape of the object, etc., so that the user can obtain a more realistic interactive experience. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is the external structure diagram of the high-density array flexible electrode for haptic feedback of the hand bionic nerve of the application;

[0047] Figure 2 is the overall schematic diagram of the high-density array flexible electrode for haptic feedback of the hand bionic nerve of the application;

[0048] Figure 3 is the structure schematic diagram of the button contact electrode;

[0049] Figure 4 is the working principle diagram of the button contact electrode;

[0050] Figure 5 is the matrix channel expansion principle diagram of the high-density electrode matrix;

[0051] Figure 6 is the flexible bottom layer distribution diagram. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0053] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0054] The application will be further described below with reference to the drawings and specific embodiments, but not as a limitation of the application.

[0055] Specific embodiment one: the following will be described with reference to the drawings Figures 1 to 6 The high-density array flexible electrode for haptic feedback of the hand bionic nerve of the application includes a flexible bottom layer 100 and a high-density electrode matrix, and the high-density electrode matrix is prepared on the flexible bottom layer 100.

[0056] The flexible bottom layer 100 is shaped like a hand and is divided into a palm area and a finger area; the high-density electrode matrix includes a plurality of electrode mesh units, which are distributed in the palm area and the finger area, and local electrical stimulation of different areas is achieved by controlling the current in different areas.

[0057] The flexible bottom layer 100 is a printed circuit board FPC made of a flexible insulating substrate, specifically including a hydrogel layer 101, a PI layer 102, a copper foil layer 103, and a non-woven fabric layer 104. The PI layer 102 is prepared on the non-woven fabric layer 104, the button-type contact electrode is prepared on the PI layer 102 using the copper foil layer 103, and the hydrogel layer 101 is used to adhere the electrode to the human skin.

[0058] The electrode array on the flexible bottom layer 100 is distributed in a high-density matrix form. The electrode arrangement of the system adopts a matrix structure, allowing precise current control of different areas of the palm and fingers. Multiple small electrodes are arranged closely to provide local electrical stimulation as needed in different positions. The high-density matrix form covers the palm area and the finger area, as shown in Figure 1 and Figure 2 :

[0059] The palm area includes a heel region, a thenar region, and a hypothenar region. The electrodes are arranged in the center and the proximal side (close to the wrist) of the palm, and the electrodes in this area are mainly used to stimulate or monitor the nerve and muscle activity of the palm. The electrodes are evenly distributed and cover the main areas of the lower part of the thumb, the heel, and the palm.

[0060] The finger area includes a knuckle region and a finger pad region. Each finger is covered with multiple pairs of electrodes, which are distributed at the joints (proximal interphalangeal joint and distal interphalangeal joint) and the finger pad of each finger, providing precise fingertip tactile feedback. Each knuckle region contains at least 4 pairs of button-type contact electrodes, and each finger pad region contains at least 9 pairs of button-type contact electrodes. The electrodes are distributed at different positions of the knuckles and the finger pads, allowing the user to perceive delicate tactile and pressure changes in the virtual environment, and achieving high-density electrode coverage in the stimulation area. Since the thumb area is a knuckle, a higher-density electrode mesh is specially designed to cover the thumb pad, the knuckle, and the palmar muscle area below it, adapting to the key role of the thumb in multidirectional movement and providing more accurate tactile feedback and force perception.

[0061] Referring to Figure 3 , the high-density electrode matrix is composed of N button-type contact electrodes, which are composed of an outer electrode A and an inner electrode B. The outer electrode A is a ring structure with a notch, and the notch is 1 / 4 to 1 / 3 of the whole ring. The inner electrode B is a round electrode, and the outer electrode A is concentrically surrounded outside the inner electrode B.

[0062] N outer layer electrodes A are connected to a first N-channel control terminal CON1, N inner layer electrodes B are connected to a second N-channel control terminal CON2, and the first and second N-channel control terminals CON1 and CON2 are respectively connected to the two ends of a direct current power supply, so that a potential difference is formed between the outer layer electrodes A and the inner layer electrodes B of each button contact to achieve electrical stimulation of the point.

[0063] Referring to Figure 4 As shown in the figure, the first and second N-channel control terminals CON1 and CON2 are respectively connected to the positive and negative poles or the negative and positive poles of the direct current power supply. The control system can switch the potential in reverse and alternately apply positive and negative voltages between the N outer layer electrodes A and the N inner layer electrodes B, thereby achieving bidirectional current stimulation.

[0064] The switches of each channel of the first and second N-channel control terminals CON1 and CON2 are independently controlled to achieve electrical stimulation of any area individually.

[0065] According to Figure 4 The arrangement of the button contact electrodes and the internal circuit connection support channel expansion, N = 16-256. The scheme can expand a 32-channel electrical stimulator to 256 channels in a matrix arrangement, enabling the number of channels to be expanded at minimal cost. Figure 1 and Figure 2 The electrode patch uses 193 channels as shown in the figure, and arranges the electrodes according to the distribution of the hand nerves on the basis of the matrix form, thereby achieving precise electrical stimulation of the entire hand.

[0066] It also includes a plurality of fixing holes for winding the array-type flexible electrode on the hand. The fixing holes are present at all positions that may require additional fixation, and the holes can facilitate the assembly of the electrode patch on the glove, or the suggested winding and wearing without a glove. The fixing holes are additionally rounded to ensure their strength and reliability, and are not easily damaged.

[0067] The material of the flexible bottom layer 100 is a printed circuit board (FPC) made of a flexible insulating substrate, and the button contacts can directly contact the human body or be pasted with hydrogel to contact the human body. It can be freely bent, wound, and folded, and can be arranged arbitrarily according to the spatial layout requirements, and can be moved and stretched arbitrarily in three-dimensional space, thereby conforming to the shape of the palm, and the corners are rounded to enhance the wear resistance of the material and improve the service life.

[0068] Through these high-density electrodes, the system can simulate various haptic feedbacks, which can be applied in virtual reality, augmented reality, or prosthetic control, helping users to perceive objects or forces in a virtual or remote environment. This may involve tactile simulation (such as texture, pressure) and force feedback.

[0069] While the application has been described with reference to particular embodiments, it is to be understood that the application is not limited to the particulars disclosed. Many modifications, variations, and applications of the application will be apparent to those skilled in the art without departing from the spirit and scope of the application as defined in the appended claims. It is therefore intended to cover all modifications and alterations that come within the scope and spirit of the application. It should be understood that all connections disclosed in the specification and drawings are exemplary. A variety of modifications and alterations can be made without departing from the scope and spirit of the application. It is intended that all such modifications and alterations be considered part of the disclosure in accordance with the appended claims.

Claims

1. A hand bionic high-density array flexible electrode for tactile feedback, characterized in that, The flexible bottom layer (100) is shaped like a hand and is divided into a palm area and a finger area; the high-density electrode matrix includes a plurality of electrode mesh units, which are distributed in the palm area and the finger area, and local electrical stimulation of different areas is realized by controlling the current of different areas. The palm area includes a heel area, a thenar area and a hypothenar area; the finger area includes knuckle areas and finger pad areas.

2. The haptics feedback oriented hand bionic nerve high-density array flexible electrode according to claim 1, wherein, The high-density electrode matrix is constructed by N button contact electrodes, which are composed of an outer electrode A and an inner electrode B; the outer electrode A is a ring structure with a notch, and the notch is 1 / 4-1 / 3 of the whole ring; the inner electrode B is a round sheet electrode; the outer electrode A is concentrically surrounded outside the inner electrode B.

3. The haptics feedback oriented hand bionic nerve high-density array flexible electrode according to claim 2, characterized in that, The N outer electrodes A are connected to a first N-channel control terminal CON1, and the N inner electrodes B are connected to a second N-channel control terminal CON2; the first N-channel control terminal CON1 and the second N-channel control terminal CON2 are respectively connected to the two ends of a direct current power supply, so that a potential difference is formed between the outer electrode A and the inner electrode B of each button contact to realize electrical stimulation of the point. The first N-channel control terminal CON1 and the second N-channel control terminal CON2 are respectively connected to the positive and negative poles or the negative and positive poles of the direct current power supply.

4. The haptics feedback oriented hand bionic nerve high-density array flexible electrode according to claim 3, characterized in that, The switches of each channel of the first N-channel control terminal CON1 and the second N-channel control terminal CON2 are independently controlled to realize electrical stimulation of any area.

5. The haptics feedback oriented hand bionic nerve high-density array flexible electrode according to claim 3, wherein, The flexible bottom layer (100) is a printed circuit board FPC made of a flexible insulating base material, specifically including a hydrogel layer (101), a PI layer (102), a copper foil layer (103) and a non-woven fabric layer (104); the PI layer (102) is prepared on the non-woven fabric layer (104), the button contact electrodes are prepared on the PI layer (102) by using the copper foil layer (103), and are pasted on the human skin through the hydrogel layer (101).

6. The haptics feedback oriented hand bionic nerve high-density arrayed flexible electrode according to claim 1, wherein, It also includes a plurality of fixing holes for winding and wearing the array type flexible electrode on the hand.

7. The haptics feedback oriented hand bionic nerve high-density arrayed flexible electrode according to claim 1, wherein, Each knuckle area contains at least 4 pairs of button contact electrodes, and each finger pad area contains at least 9 pairs of button contact electrodes.

8. The haptics feedback oriented hand bionic nerve high-density arrayed flexible electrode according to claim 3, wherein, N＝16～256。 9. The haptics feedback oriented hand bionic nerve high-density arrayed flexible electrode according to claim 2, wherein, ​

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