Bending angle self-feedback underwater rigidity-variable soft dexterous hand and using method thereof

Abstract

The invention provides a bending angle self-feedback underwater variable-rigidity soft dexterous hand which comprises soft flexible fingers, a bending self-feedback unit and a dexterous palm, and each soft flexible finger comprises a paper folding framework, a driving skin, a variable-rigidity unit and a driving channel; the bending self-feedback unit comprises a plurality of electrode patches, a scanning circuit and an upper computer, and the electrode patches are attached to the long side of the origami skeleton joint in parallel; driving the inner surface of the skin to gild; the signal input end of the scanning circuit is connected with the electrode patch through a wire, a contact signal of the electrode patch is collected in real time and uploaded to an upper computer, and the bending state of the soft flexible finger is monitored. The dexterous palm is connected with the flexible finger connectors, and the flexible palm and the flexible fingers are integrally assembled through the flexible finger connectors. According to the invention, the load capacity of the flexible finger is enhanced while the flexibility of the flexible finger is ensured, the deformation and rigidity changing functions of the flexible finger are realized through one power source, and the bending self-feedback unit realizes bending angle self-driven monitoring without power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of soft dexterous hands, and more particularly, to a bending angle self-feedback underwater variable stiffness soft dexterous hand and a method for using the same. Background Art

[0002] The ocean is the origin of human life, supporting the sustainable development of humanity with its rich water resources, mineral resources, and biological resources. With the continuous development of technology, people's exploration of ocean resources has gradually shifted to the deep sea. Deep sea exploration is a strategic approach and an important means for humanity to achieve sustainable development at the present stage.

[0003] Manipulators are of great significance for ocean exploration, seabed resource development, seabed relic detection, etc. Traditional rigid manipulators are made of hard materials. Although they have high control precision, they have poor flexibility, low safety factor, and low adaptability. They are not easy to work in unstructured environments and are difficult to apply to the grasping of soft or fragile objects such as underwater organisms, seabed plants, and ancient substances.

[0004] In contrast, soft dexterous hands are made of flexible materials, have the ability of continuous deformation, have better flexibility and environmental adaptability, and involve fewer electronic components. Therefore, the underwater sealing requirements are lower. In recent decades, the technology of soft dexterous hands has developed rapidly, making up for many shortcomings of traditional rigid manipulators and having great application potential in the field of underwater operations.

[0005] Underwater soft dexterous hands are usually made by injection molding of flexible materials. Although they have good compliance, their load capacity is weak. Variable stiffness can greatly enhance their load capacity. The variable stiffness of soft dexterous hands is usually achieved by particle interference, layer interference, fiber interference, or special materials, and is realized by applying negative pressure, changing temperature, light, etc. Single methods have problems such as limited variable stiffness ability and slow response time. The variable stiffness part often affects the deformation of soft dexterous hands as a single component.

[0006] When a dexterous hand performs a grasping task, the monitoring of its deformation state often affects the grasping success rate and grasping efficiency, etc. And the underwater environment, as an unstructured environment, is often difficult to monitor the state of the dexterous hand. The sealing of traditional electronic sensors is a major challenge during underwater operations. Piezoelectric and piezoresistive flexible sensors utilize the characteristics of materials to achieve sensing functions, but these sensors often require an external power supply and are affected by a large hydrostatic pressure when used in the deep sea, causing them to exceed the measurement or sensing range and affecting their working performance. Therefore, a real-time monitorable underwater variable stiffness soft finger and dexterous hand and method are meaningful. Summary of the Invention

[0007] According to the above-mentioned technical problems, a variable stiffness underwater soft dexterous hand with self-feedback of bending angle is provided. The soft dexterous hand of the present invention increases the load capacity better while ensuring compliance, and its deformation and variable stiffness functions are both realized by a single power source, and the bending self-feedback unit can monitor the bending angle self-driven without power supply.

[0008] The technical means adopted by the present invention are as follows:

[0009] A variable stiffness underwater soft dexterous hand with self-feedback of bending angle, comprising: soft fingers, a bending self-feedback unit and a dexterous palm, wherein:

[0010] The soft finger includes: an origami skeleton, a driving skin, a variable stiffness unit and a driving channel, wherein:

[0011] The origami skeleton is formed by folding a flexible sheet to form an origami skeleton end and a plurality of origami skeleton joints; and each origami skeleton joint is provided with a long side and a short side;

[0012] The driving skin completely wraps and seals the origami skeleton and the variable stiffness unit, and a port is opened at the end;

[0013] The variable stiffness unit includes a plurality of single variable stiffness units, and the structure of each variable stiffness unit is the same. The plurality of variable stiffness units are placed in parallel and obliquely in the gap below the origami skeleton; each variable stiffness unit includes a variable stiffness skin, pores and particles. The pores are opened on the variable stiffness skin, and the diameter of the pores is smaller than the diameter of the particles. The variable stiffness skin is filled with particles and completely wraps the particles;

[0014] One end of the driving channel is connected to the port opened at the connection end of the driving skin, and the other end is connected to the driving device to realize the driving of the soft finger; the driving device extracts the liquid in the internal space of the soft finger through the driving channel, so that the driving skin sinks towards the origami skeleton joint and generates a pulling force on the origami skeleton, causing the soft finger to bend and deform to one side;

[0015] The bending self-feedback pole piece includes: an electrode patch, a gold-plated layer of the driving skin, a scanning circuit and a host computer, wherein:

[0016] A plurality of electrode patches are provided and are all fixedly arranged in parallel on the long side of the origami skeleton joint and are in direct contact with the filled liquid;

[0017] The gold-plated layer of the driving skin is to plate gold on the inner surface of the driving skin;

[0018] The scanning circuit and the host computer are connected to the electrode patch through a wire, and are used to receive the current signal collected by the electrode patch in real time, so as to monitor the real-time deformation state of the soft finger;

[0019] The dexterous palm, imitating the structure of the human palm, is connected to a number of flexible finger connectors, and the overall assembly with the flexible fingers is realized through the flexible finger connectors; electrode patches are fixed on the surface of the dexterous palm, and whether the dexterous hand contacts an object is judged by judging the current signal generated by the contact between the electrode patch and the object.

[0020] Further, during the bending process of the flexible finger, the driving skin is driven to sink downward, and as the bending angle increases, the sinking depth increases, and thus the contact area with the long side of the origami skeleton joint also increases. During the bending deformation process of the flexible finger, the sensing patch contacts the electrode patch one by one, and the surface of the electrode patch changes from a solid-liquid interface to a solid-solid interface, and a current signal is generated during the transformation process to realize the monitoring of the deformation state of the flexible finger.

[0021] Further, the flexible finger is used for the bending deformation of the finger. The inside of the flexible finger is filled with liquid. When the liquid inside is pumped out, the flexible finger generates a bending motion under negative pressure.

[0022] Further, when the driving device pumps the liquid in the internal space of the flexible finger through the driving channel, a negative pressure is generated inside the flexible finger. Since the variable stiffness skin surface contains pores, under the action of the negative pressure, the variable stiffness skin squeezes the internal filling particles, and the particles squeeze each other to realize particle interference variable stiffness. When an external force acts, the friction force is significantly increased, and thus the stiffness of the flexible finger is increased.

[0023] Further, when a negative pressure is generated inside the flexible finger, multiple parallel and obliquely placed variable stiffness units squeeze each other, and when an external force acts, the friction force is significantly increased to realize layer interference variable stiffness, which acts simultaneously with the particle interference variable stiffness to further increase the stiffness of the flexible finger;

[0024] Further, when a negative pressure is generated inside the flexible finger, the flexible finger is bent to realize the increase of the load capacity by hybrid interference variable stiffness. As the negative pressure increases, the bending angle of the flexible finger increases, and the stiffness of the flexible finger increases.

[0025] Further, the electrode patch is made of a conductor material or a semiconductor material.

[0026] The present invention also provides a usage method of the underwater variable stiffness soft dexterous hand based on the self-feedback of the bending angle, including:

[0027] S1. The soft dexterous hand dives underwater close to an object, and the electrode patch is in direct contact with water, and a double electric layer will be spontaneously generated on the electrode surface;

[0028] S2. The dexterous palm approaches the object to be grasped, and the electrode patch fixed on the surface contacts the object. The contact area of the solid-liquid interface changes, and the double electric layer generated at the solid-liquid interface changes dynamically, generating a current signal to determine the approach to the object;

[0029] S3. After detecting the approaching object, the soft flexible finger starts to work, and the electrode patch attached to the origami skeleton generates an electric current signal.

[0030] S4. When the soft flexible finger no longer generates an electric current signal, it indicates that the soft dexterous hand has grasped the object to be grasped. Then lift the soft dexterous hand to complete the entire grasping process.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] 1. A soft dexterous hand with self-feedback of bending angle and variable stiffness underwater provided by the present invention can detect the deformation state of the flexible finger in real time through self-perception in an underwater unstructured environment.

[0033] 2. A soft dexterous hand with self-feedback of bending angle and variable stiffness underwater provided by the present invention can effectively increase the load capacity of the soft flexible finger by means of hybrid variable stiffness, and only one driving source is required to realize the deformation and variable stiffness of the soft flexible finger, effectively reducing the number of underwater system devices.

[0034] 3. A soft dexterous hand with self-feedback of bending angle and variable stiffness underwater provided by the present invention uses liquid drive for its soft flexible finger, which can better balance the deep-sea hydrostatic pressure.

[0035] 4. A soft dexterous hand with self-feedback of bending angle and variable stiffness underwater provided by the present invention does not require external power supply, has low system power consumption, and can adapt to the deep-sea hydrostatic pressure.

[0036] 5. A soft dexterous hand with self-feedback of bending angle and variable stiffness underwater provided by the present invention is used in an underwater unstructured environment, has simple operation, and a simple grasping process.

[0037] Based on the above reasons, the present invention can be widely promoted in the fields of soft dexterous hands, etc. Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0039] Figure 1 It is a schematic structural diagram of a soft dexterous hand with self-feedback of bending angle and variable stiffness underwater according to the present invention.

[0040] Figure 2 It is a schematic structural diagram of the flexible finger of a soft dexterous hand with self-feedback of bending angle and variable stiffness underwater according to the present invention.

[0041] Figure 3 This is a schematic structural diagram of the variable stiffness unit of the present invention.

[0042] Figure 4 This is a schematic structural diagram of the bending self-feedback unit of the present invention.

[0043] Figure 5 This is a schematic diagram of the principle of the dynamic change process of the electric double layer on the surface during the detection process of the self-feedback unit of the present invention.

[0044] In the figure: 1. Soft flexible finger; 2. Bending self-feedback unit; 3. Dexterous palm; 4. Origami skeleton; 5. Driving skin; 6. Variable stiffness unit; 7. Driving channel; 8. Electrode patch; 9. Gold plating layer of the driving skin; 10. Variable stiffness skin; 11. Pore; 12. Particle; 13. Scanning circuit; 14. Host computer; 15. Wire; 16. Filling liquid; 17. Electric double layer; 17a. Electric double layer on the electrode surface in the initial state; 17b. Electric double layer on the electrode surface after contact; 18. Flexible finger connector. Specific embodiments

[0045] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0047] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0048] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary statements, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be construed as limiting the protection scope of the present invention: the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0050] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0051] In addition, it should be noted that the use of words such as "first", "second", etc. to limit components is only for the convenience of distinguishing the corresponding components. Without otherwise stating, the above words have no special meanings, and thus cannot be construed as limiting the protection scope of the present invention.

[0052] Such as Figure 1As shown in the figure, the present invention provides a variable stiffness underwater soft dexterous hand with self-feedback on bending angle, comprising: a soft finger 1, a bending self-feedback unit 2, and a dexterous palm 3, wherein:

[0053] The soft finger 1, as Figure 2 shown, comprises: an origami skeleton 4, a driving skin 5, a variable stiffness unit 6, and a driving channel 7, wherein:

[0054] The origami skeleton 4 is formed by folding a flexible sheet to form an origami skeleton end and a plurality of origami skeleton joints; and each origami skeleton joint is provided with a long side and a short side;

[0055] The driving skin 5 completely wraps and seals the origami skeleton 4 and the variable stiffness unit 6, and has a port opened at the end;

[0056] There are a plurality of variable stiffness units 6, and the structure of each variable stiffness unit 6 is the same, and the plurality of variable stiffness units 6 are placed obliquely in parallel in the gap below the origami skeleton 4; as Figure 3 shown, each variable stiffness unit 6 includes a variable stiffness skin 10, pores 11, and particles 12. The pores 11 are opened on the variable stiffness skin 10, and the diameter of the pores 11 is smaller than the diameter of the particles. The variable stiffness skin 10 is filled with particles 12 and completely wraps the particles 12;

[0057] One end of the driving channel 7 is connected to the port opened at the connection end of the driving skin 5, and the other end is connected to a driving device to realize the driving of the soft finger 1; the driving device extracts the liquid 16 in the internal space of the soft finger 1 through the driving channel 7, so that the driving skin 6 sinks into the origami skeleton joint and generates a pulling force on the origami skeleton 4, causing the soft finger 1 to bend and deform to one side;

[0058] As Figure 4 shown, the bending self-feedback unit 2 includes: electrode patches 8, a gold plating layer 9 on the driving skin, a scanning circuit 13, and a host computer 14, wherein:

[0059] A plurality of electrode patches 8 are provided and are all fixedly arranged in parallel on the long side of the origami skeleton joint and are in direct contact with the filled liquid 16;

[0060] The induction patch 9 is fixed on the inner surface of the driving skin 5 above the origami skeleton joint;

[0061] The scanning circuit 13 and the host computer 14 are connected to the electrode patches 8 through wires 15, and are used to receive in real time the current signals collected by the electrode patches 8, so as to monitor the real-time deformation state of the soft finger 1;

[0062] Continue to refer to Figure 1, the dexterous palm 3, imitating the structure of the human palm, is connected to a number of flexible finger connectors 18, and the overall assembly with the flexible finger 1 is realized through the flexible finger connectors 18; electrode patches 8 are fixed on the surface of the dexterous palm 3, and it is judged whether the dexterous hand contacts an object by judging the current signal generated by the contact between the electrode patch 8 and the object.

[0063] In order to more clearly understand the structure and operation principle of the invention, in this embodiment, the origami skeleton 4 is folded from a polyester sheet, the variable stiffness unit 6 is made by wrapping particles 12 with a TPU film with pores, and the origami skeleton 4 and the variable stiffness skin 10 with particles 12 are completely sealed with a TPU film, leaving only an interface of a driving channel 7 connected to the driving device, wherein the sealing method of the TPU is realized by a heat sealer.

[0064] During specific implementation, as a preferred implementation manner of the present invention, the flexible finger 1 is used for the bending deformation of the finger. The inside of the flexible finger 1 is filled with liquid 16. When the internal liquid 16 is pumped out, the flexible finger 1 generates a bending motion under negative pressure.

[0065] During specific implementation, as a preferred implementation manner of the present invention, during the bending process of the flexible finger 1, the driving skin 6 is depressed downward, and as the bending angle increases, the depression depth increases, and thus the contact area with the long side of the origami skeleton joint also increases accordingly.

[0066] During specific implementation, as a preferred implementation manner of the present invention, when the driving device extracts the liquid 16 in the internal space of the flexible finger 1 through the driving channel 7, a negative pressure is generated inside the flexible finger 1. Since the surface of the variable stiffness skin 10 contains pores 11, under the action of the negative pressure, the variable stiffness skin 10 squeezes the internal filling particles 12, and the particles 12 squeeze each other to realize particle interference variable stiffness. When an external force acts, the friction force is significantly increased, and thus the stiffness of the flexible finger 1 is increased.

[0067] During specific implementation, as a preferred implementation manner of the present invention, when a negative pressure is generated inside the flexible finger 1, the plurality of parallel and obliquely arranged variable stiffness units 6 will also squeeze each other, and when an external force acts, the friction force is significantly increased to realize layer interference variable stiffness, which acts simultaneously with the particle interference to further increase the stiffness of the flexible finger 1.

[0068] During specific implementation, as a preferred implementation manner of the present invention, when a negative pressure is generated inside the flexible finger 1, it will cause the flexible finger 1 to bend, realizing hybrid interference variable stiffness to increase the load capacity. As the negative pressure increases, the bending angle of the flexible finger 1 increases, and the stiffness of the flexible finger 1 increases.

[0069] During specific implementation, as a preferred implementation manner of the present invention, such as Figure 5As shown, during the bending deformation process of the soft flexible finger 1, the driving skin gold plating layer 9 contacts the electrode patches 8 one by one. The surface of the electrode patch 8 changes from a solid-liquid (electrode-water) interface to a solid-solid (electrode-metal patch) interface. During this process, a current signal is generated to realize the monitoring of the deformation state of the soft flexible finger 1.

[0070] In specific implementation, as a preferred implementation manner of the present invention, the electrode patch 8 is made of a conductor material or a semiconductor material.

[0071] The present invention also provides a usage method of the underwater variable stiffness soft dexterous hand based on the self-feedback of the bending angle, including:

[0072] S1. The soft dexterous hand dives underwater and approaches an object. The electrode patch 8 is in direct contact with water, and a double electric layer 17 will be spontaneously generated on the electrode surface, as Figure 5 shown.

[0073] S2. The dexterous palm 3 approaches the object to be grasped. The electrode patch 8 fixed on the surface contacts the object, and the contact area of the solid-liquid interface will change. The double electric layer 17 generated at the solid-liquid interface will change dynamically, generating a current signal to determine the approach to the object, as Figure 5 shown.

[0074] S3. After it is detected that the object is approached, the soft flexible finger 1 starts to work, and the electrode patch 8 attached to the origami skeleton 4 generates a current signal;

[0075] S4. When the soft flexible finger 1 no longer generates a current signal, it indicates that the soft dexterous hand has grasped the object to be grasped, and the soft dexterous hand is lifted to complete the entire grasping process.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible underwater soft hand with variable stiffness and self-feedback bending angle, characterized in that: include: A soft finger (1), a bending self-feedback unit (2) and a dexterous palm (3), wherein: The soft finger (1) comprises an origami skeleton (4), a driving skin (5), a variable stiffness unit (6) and a driving channel (7), wherein: The origami skeleton (4) is formed by folding a flexible thin sheet to form an origami skeleton end and a plurality of origami skeleton joints; and each origami skeleton joint is provided with a long side and a short side; The driving skin (5) completely wraps and seals the origami skeleton (4) and the variable stiffness unit (6), and a port is opened at the end; The variable stiffness unit (6) includes a plurality of single variable stiffness units, and each variable stiffness unit (6) has the same structure. The plurality of variable stiffness units (6) are placed in parallel and obliquely in the gap below the origami skeleton (4); each variable stiffness unit (6) includes a variable stiffness skin (10), a pore (11) and a particle (12); the pore (11) is provided on the variable stiffness skin (10), and the diameter of the pore (11) is smaller than the diameter of the particle; the variable stiffness skin (10) is filled with the particle (12), and the particle (12) is completely wrapped; One end of the driving channel (7) is connected to a port opened at the connecting end of the driving skin (5), and the other end is connected to a driving device to realize driving of the soft finger (1); the driving device extracts liquid (16) in the internal space of the soft finger (1) through the driving channel (7), so that the driving skin (6) is recessed toward the origami skeleton joint, and generates a pulling force on the origami skeleton (4), so that the soft finger (1) is bent and deformed to one side; The bending self-feedback unit (2) comprises an electrode patch (8), a driving skin gold-plated layer (9), a scanning circuit (13) and a host computer (14), wherein: A plurality of electrode patches (8) are provided, and are all fixed in parallel to the long sides of the origami skeleton joints and are in direct contact with the filling liquid (16); The driving skin gold-plated layer (9) is formed by gold-plating the inner surface of the driving skin (5); The scanning circuit (13) and the host computer (14) are connected to the electrode patch (8) via a wire (15) and are used to receive the current signal collected by the electrode patch (8) in real time, thereby monitoring the real-time deformation state of the soft finger (1); The dexterous palm (3) imitates the structure of a human palm and is connected to a plurality of smart finger connectors (18), and is integrally assembled with the soft smart fingers (1) through the smart finger connectors (18); an electrode patch (8) is fixed on the surface of the dexterous palm (3), and whether the dexterous palm is in contact with an object is determined by judging the current signal generated by the electrode patch (8) in contact with the object.

2. The bending angle self-feedback underwater variable stiffness soft dexterous hand according to claim 1 is characterized in that: During the bending process of the soft finger (1), the driving skin (6) is sunken downward, and as the bending angle increases, the depth of the sunken area increases, thereby increasing the contact area with the long side of the origami skeleton joint; during the bending deformation process of the soft finger (1), the driving skin gold-plated layer (9) contacts the electrode patches (8) one by one, and the surface of the electrode patches (8) changes from a solid-liquid interface to a solid-solid interface. During the transformation process, a current signal is generated, thereby realizing the deformation state monitoring of the soft finger (1).

3. The bending angle self-feedback underwater variable stiffness soft dexterous hand according to claim 1 is characterized in that: The soft flexible finger (1) is used for flexible finger bending and deformation. The interior of the soft flexible finger (1) is filled with liquid (16). When the internal liquid (16) is extracted, the soft flexible finger (1) is subjected to negative pressure and generates bending movement.

4. The bending angle self-feedback underwater variable stiffness soft dexterous hand according to claim 1 is characterized in that: When the driving device extracts the liquid (16) in the internal space of the soft finger (1) through the driving channel (7), negative pressure is generated inside the soft finger (1). Since the surface of the variable stiffness skin (10) contains pores (11), the variable stiffness skin (10) squeezes the particles (12) filled inside under the action of negative pressure. The particles (12) squeeze each other to achieve particle interference and variable stiffness. When subjected to external force, the friction force is significantly increased, thereby increasing the stiffness of the soft finger (1).

5. The bending angle self-feedback underwater variable stiffness soft dexterous hand according to claim 4 is characterized in that: When negative pressure is generated inside the soft finger (1), the multiple parallel and oblique variable stiffness units (6) squeeze each other, significantly increasing the friction force when subjected to external force to achieve layer interference variable stiffness, and acting simultaneously with the particle interference variable stiffness, further increasing the stiffness of the soft finger (1).

6. The bending angle self-feedback underwater variable stiffness soft dexterous hand according to claim 4 is characterized in that: When negative pressure is generated inside the soft finger (1), the soft finger (1) bends, achieving mixed interference variable stiffness to increase load capacity. As the negative pressure increases, the bending angle of the soft finger (1) increases, and the stiffness of the soft finger (1) increases.

7. The bending angle self-feedback underwater variable stiffness soft dexterous hand according to claim 1 is characterized in that: The electrode patch (8) is made of a conductive material or a semiconductor material.

8. A method for using the underwater variable stiffness soft dexterous hand with self-feedback bending angle according to any one of claims 1 to 7, characterized in that: include: S1. The soft dexterous hand goes deep into the water and approaches an object. The electrode patch (8) is in direct contact with the water, and a double electric layer (17) is spontaneously generated on the electrode surface. S2, the dexterous palm (3) approaches the grasped object, the electrode patch (8) fixed on the surface contacts the object, the contact area of ​​the solid-liquid interface changes, the double electric layer (17) generated at the solid-liquid interface changes dynamically, and a current signal is generated to determine that the object is approaching; S3, after detecting an approaching object, the soft finger (1) starts to work, and the electrode patch (8) attached to the origami frame (4) generates a current signal; S4. When the soft dexterous finger (1) no longer generates a current signal, it indicates that the soft dexterous hand has grasped the object, and the soft dexterous hand is raised to complete the entire grasping process.

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