Variable-stiffness soft claw and variable-stiffness soft gripper based on electrorheological elastomer

Abstract

The invention discloses a variable-rigidity soft claw and a variable-rigidity soft gripper based on electrorheological elastomers, and relates to the technical field of soft grippers, the variable-rigidity soft claw comprises a driving structure and a plurality of electrorheological elastomers, each electrorheological elastomer is fixedly connected to the driving structure, and the electrorheological elastomers are fixedly connected to the driving structure. The electrorheological elastomers are used for being connected with an external power source, and the driving structure can drive the electrorheological elastomers to make contact with or be separated from a grabbed object. The variable-rigidity soft claw and the variable-rigidity soft gripper based on the electrorheological elastomer are higher in adaptability and better in matching degree with a gripped object.

Description

Technical Field

[0001] The present invention relates to the technical field of soft grippers, and particularly to a variable-stiffness soft claw and a variable-stiffness soft gripper based on electrorheological elastomers. Background Art

[0002] Current mechanical grippers are usually made of rigid materials with a fixed shape and relatively low flexibility. They can generally only adapt to objects of specific shapes and sizes, and are likely to damage the grasped objects when gripping fragile or soft objects. To address the above problems, some mechanical grippers with variable-stiffness functions have gradually emerged, which make the gripper and the grasped object more compatible by changing the stiffness of the gripper. However, the current variable-stiffness grippers still have poor adaptability and cannot fit well with the grasped objects. Therefore, there is an urgent need for a variable-stiffness soft claw and a variable-stiffness soft gripper based on electrorheological elastomers with stronger adaptability and better fit with the grasped objects. Summary of the Invention

[0003] The purpose of the present invention is to provide a variable-stiffness soft claw and a variable-stiffness soft gripper based on electrorheological elastomers to solve the problems existing in the above-mentioned prior art, with stronger adaptability and better fit with the grasped objects.

[0004] To achieve the above purpose, the present invention provides the following solutions:

[0005] The present invention provides a variable-stiffness soft claw, including: a driving structure and a plurality of electrorheological elastomers, each of the electrorheological elastomers is fixedly connected to the driving structure, each of the electrorheological elastomers is used to connect to an external power source, and the driving structure can drive the electrorheological elastomers to contact or separate from the grasped object.

[0006] In some embodiments, the driving structure is a pneumatic deformation layer, the pneumatic deformation layer can deform, there is a sealed deformation cavity inside the pneumatic deformation layer, and a deformation air port communicating the deformation cavity and the outside is provided on the pneumatic deformation layer. Inflating or deflating the deformation cavity can make the pneumatic deformation layer bend or straighten.

[0007] In some embodiments, it further includes an air pipe, one end of the air pipe is connected and communicated with the deformation air port, and the other end is used to connect to an air pump.

[0008] In some embodiments, it further includes a first electrode and a plurality of second electrodes. The first electrode is fixedly connected to one side of the pneumatic deformation layer, each of the electrorheological elastomers is fixedly connected to the first electrode in sequence, and each of the second electrodes is fixedly connected to the side of each of the electrorheological elastomers away from the first electrode.

[0009] In some embodiments, the pneumatic deformation layer is made of fabric material.

[0010] In some embodiments, both the first electrode and the second electrode are flexible electrodes.

[0011] In some embodiments, the electrorheological elastomer includes an elastic polymer matrix and conductive particles, and the conductive particles are embedded in the elastic polymer matrix.

[0012] The present invention also provides a variable stiffness soft gripper, which includes a base and a plurality of the above-mentioned variable stiffness soft claws, and each of the variable stiffness soft claws is fixedly connected to one side of the base.

[0013] In some embodiments, each of the variable stiffness soft claws is arranged at equal intervals along a first circumferential trajectory.

[0014] In some embodiments, the driving structure is a pneumatic deformation layer, and a sealed deformation cavity is formed in the pneumatic deformation layer. Inflating or deflating the deformation cavity can cause the pneumatic deformation layer to bend or straighten; each of the variable stiffness soft claws is fixedly connected to the installation side of the base. The end of each variable stiffness soft claw close to the base is the first end, and the end of each variable stiffness soft claw far from the base is the second end. A straight line passing through the center of the first circumferential trajectory and perpendicular to the installation side is the first straight line. When the pneumatic deformation layer bends, each of the second ends is closer to the first straight line than each of the first ends.

[0015] The present invention has achieved the following technical effects compared with the prior art:

[0016] The variable stiffness soft claw provided by the present invention can control the contact or separation between the variable stiffness layer and the object to be grasped through a driving structure to grasp the object. When grasping an object, after the variable stiffness layer contacts the object to be grasped, an electric field is applied to the electrorheological elastomer through a flexible electrode, and the conductive particles will rearrange under the action of the electric field to form a chain-like or columnar structure. This change in structure will cause an increase in the stiffness of the electrorheological elastomer. When it is necessary to release the grasped object, the electric field is removed, and the stiffness of the electrorheological elastomer decreases. At the same time, different magnitudes of current can be introduced into different electrorheological elastomers to make different electrorheological elastomers have different stiffnesses, so that the variable stiffness soft claw can fit better with the object to be grasped and the applicability of the variable stiffness soft claw is stronger. Description of the Drawings

[0017] 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 in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 This is a three-dimensional structure diagram of a variable stiffness soft gripper in some embodiments of the present invention;

[0019] Figure 2 This is a three-dimensional structure diagram of a variable stiffness soft claw in some embodiments of the present invention;

[0020] Figure 3 This is a three-dimensional structure diagram of the first mold in the third embodiment;

[0021] In the figure: 1, electrorheological elastomer; 2, pneumatic deformation layer; 3, air pipe; 4, first electrode; 5, second electrode; 6, base; 7, first end; 8, second end; 9 - first mold. Specific embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying 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. 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.

[0023] The purpose of the present invention is to provide a variable stiffness soft claw and a variable stiffness soft gripper based on electrorheological elastomers to solve the problems existing in the above-mentioned prior art, with stronger flexibility and a wider application range.

[0024] To make the above objects, features, and advantages of the present invention more clearly understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Embodiment 1

[0026] This embodiment provides a variable stiffness soft claw, as Figure 2 shown, including a driving structure and a plurality of electrorheological elastomers 1. Each electrorheological elastomer 1 is fixedly connected to the driving structure, and each electrorheological elastomer 1 is used to connect to an external power supply. The driving structure can drive the electrorheological elastomer 1 to contact or separate from the object to be grasped.

[0027] In the variable stiffness soft gripper of this embodiment, the variable stiffness layer can be controlled by a driving structure to contact or separate from the object to be grasped, so as to grasp the object. When grasping an object, after the variable stiffness layer contacts the object to be grasped, an electric field is applied to the electrorheological elastomer 1 through the first electrode 4 and the second electrode 5. The conductive particles will rearrange under the action of the electric field to form a chain-like or columnar structure. This change in the structure will cause the stiffness of the electrorheological elastomer 1 to increase. When it is necessary to release the grasped object, the electric field is removed, and the stiffness of the electrorheological elastomer 1 decreases. At the same time, different magnitudes of current can also be passed into different electrorheological elastomers 1, so that different electrorheological elastomers 1 have different stiffnesses, thereby enabling the variable stiffness soft gripper to fit better with the object to be grasped and making the variable stiffness soft gripper more applicable.

[0028] In an implementation manner of this embodiment, the driving structure is a pneumatic deformation layer 2. The pneumatic deformation layer 2 can deform. There is a sealed deformation cavity inside the pneumatic deformation layer 2. A deformation air port communicating the deformation cavity and the outside is provided on the pneumatic deformation layer 2. Inflating or deflating the deformation cavity can make the pneumatic deformation layer 2 bend or straighten. By inflating the deformation cavity through the deformation air port, the pneumatic deformation layer 2 can bend and make the electrorheological elastomer 1 contact the object to be grasped. After releasing the gas in the deformation cavity through the deformation air port, the pneumatic deformation layer 2 can straighten and make the electrorheological elastomer 1 away from the object to be grasped.

[0029] It should be noted that in addition to the pneumatic deformation layer 2, electronic devices such as a linear motion module and a robotic arm can also be used to replace the pneumatic deformation layer 2. For example, each electrorheological elastomer 1 can be fixedly connected to the free end of the linear motion module, and then the position of the electrorheological elastomer 1 can be controlled by the free end of the linear motion module to make the electrorheological elastomer 1 contact or separate from the object to be grasped.

[0030] In order to facilitate the ventilation of the pneumatic deformation layer 2, in an implementation manner of this embodiment, the variable stiffness soft gripper of this embodiment further includes an air pipe 3. One end of the air pipe 3 is connected and communicated with the deformation air port, and the other end is used to connect to an air pump.

[0031] In order to facilitate the energization of the electrorheological elastomer 1, in an implementation manner of this embodiment, the variable stiffness soft gripper of this embodiment further includes a first electrode 4 and a plurality of second electrodes 5. The first electrode 4 is fixedly connected to one side of the pneumatic deformation layer 2. Each electrorheological elastomer 1 is fixedly connected to the first electrode 4 in sequence. Each second electrode 5 is fixedly connected to the side of each electrorheological elastomer 1 away from the first electrode 4. Both the first electrode 4 and the second electrode 5 are used to connect to an external power supply.

[0032] In an implementation manner of the first embodiment, the pneumatic deformation layer 2 is made of fabric. The fabric material is a lightweight flexible material, which can reduce the overall weight of the variable stiffness soft gripper. At the same time, it has good tensile strength, wear resistance and high load-bearing capacity, and has good waterproof and dustproof performance, suitable for a variety of working environments.

[0033] In an implementation manner of the first embodiment, both the first electrode 4 and the second electrode 5 are flexible electrodes. The shape of the flexible electrode can be changed without affecting its conductivity, and it can deform together with the electrorheological elastomer 1 while being connected to an external circuit.

[0034] In an implementation manner of the first embodiment, the electrorheological elastomer 1 includes an elastic polymer matrix and conductive particles, and the conductive particles are embedded in the elastic polymer matrix. Compared with electrorheological fluid, the electrorheological elastomer has a low leakage risk, better mechanical strength and stability, and is easier to achieve local control.

[0035] Embodiment Two

[0036] This embodiment provides a variable stiffness soft gripper, as Figure 1 shown, including a base 6 and a plurality of variable stiffness soft grippers in the first embodiment, and each variable stiffness soft gripper is fixedly connected to one side of the base 6.

[0037] In the variable stiffness soft gripper of this embodiment, the electrorheological elastomer 1 can quickly respond to the change of the electric field, and then change its own stiffness. By passing different magnitudes of current into different electrorheological elastomers 1, the adaptability of the variable stiffness soft gripper is improved, so that the variable stiffness soft gripper can adapt to more objects to be grasped.

[0038] In order to make the force exerted by the variable stiffness soft gripper on the object to be grasped more uniform, in an implementation manner of this embodiment, each variable stiffness soft gripper is arranged in sequence at equal intervals along a circular trajectory.

[0039] In an implementation manner of the first embodiment, the driving structure is a pneumatic deformation layer 2. There is a sealed deformation cavity inside the pneumatic deformation layer 2. Inflating or deflating the deformation cavity can cause the pneumatic deformation layer 2 to bend or straighten. Each variable stiffness soft claw is fixedly connected to the installation side of the base 6. The end of each variable stiffness soft claw close to the base 6 is the first end 7, and the end of each variable stiffness soft claw far from the base 6 is the second end 8. The straight line passing through the center of the first circular trajectory and perpendicular to the installation side is the first straight line. When the pneumatic deformation layer 2 bends, each second end 8 is closer to the first straight line than each first end 7. When grasping an object, place the object between the variable stiffness soft claws, and inflate the pneumatic deformation layer 2. When the pneumatic deformation layer 2 bends, each second end 8 is closer to the first straight line than each first end 7 and contacts the object to be grasped, thereby grasping the object. When it is necessary to release the object, discharge the gas in the pneumatic deformation layer 2. Each second end 8 is farther from the first straight line and away from the object than each first end 7, and the object is separated from the variable stiffness soft gripper.

[0040] Embodiment Three

[0041] This embodiment provides a method for manufacturing the pneumatic deformation layer 2 in some implementation manners of the first embodiment:

[0042] Use 3D printing technology to print the first mold 9 as shown in Figure 3 The material of the first mold 9 is water-soluble polyvinyl alcohol (PVA);

[0043] Cover the fabric on all outer sides of the first mold 9, use an electric soldering iron to weld the adjacent fabrics together, and then inject 60°C water into the first mold 9 to dissolve the first mold 9;

[0044] After the first mold 9 is dissolved, air-dry the fabric, then use an electric soldering iron to supplement the welding of the joints where the fabrics are not completely sealed, trim the excess fabric with scissors, and finally test the airtightness of the fabric to obtain the pneumatic deformation layer 2.

[0045] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A variable stiffness soft claw based on electrorheological elastomer, characterized by: include: A driving structure and a plurality of electrorheological elastomers, each of which is fixedly connected to the driving structure, each of which is connected to an external power source, and the driving structure can drive the electrorheological elastomer to contact or separate from the grasped object.

2. The variable stiffness soft claw based on electrorheological elastomer according to claim 1, characterized in that: The driving structure is a pneumatic deformation layer, which is deformable and has a sealed deformation cavity therein. The pneumatic deformation layer is provided with a deformation air port connecting the deformation cavity and the outside world. Inflating or deflating the deformation cavity can bend or straighten the pneumatic deformation layer.

3. The variable stiffness soft claw based on electrorheological elastomer according to claim 2, characterized in that: It also includes an air pipe, one end of which is connected to and communicated with the deformed air port, and the other end of which is used to connect to an air pump.

4. The variable stiffness soft claw based on electrorheological elastomer according to claim 2, characterized in that: It also includes a first electrode and multiple second electrodes, the first electrode is fixedly connected to one side of the pneumatic deformation layer, each electrorheological elastomer is fixedly connected to the first electrode in turn, and each second electrode is fixedly connected to the side of each electrorheological elastomer away from the first electrode.

5. The variable stiffness soft claw based on electrorheological elastomer according to claim 2, characterized in that: The pneumatic deformation layer is made of fabric.

6. The variable stiffness soft claw based on electrorheological elastomer according to claim 4, characterized in that: The first electrode and the second electrode are both flexible electrodes.

7. The variable stiffness soft claw based on electrorheological elastomer according to claim 1, characterized in that: The electrorheological elastomer includes an elastic polymer matrix and conductive particles embedded in the elastic polymer matrix.

8. A variable stiffness soft gripper based on electrorheological elastomer, characterized by: It comprises a base and a plurality of variable-rigidity soft claws according to any one of claims 1 to 7, wherein each of the variable-rigidity soft claws is fixedly connected to one side of the base.

9. The variable stiffness soft gripper based on electrorheological elastomer according to claim 8, characterized in that: The variable-rigidity soft claws are arranged in sequence at equal intervals along the first circular trajectory.

10. The variable stiffness soft gripper based on electrorheological elastomer according to claim 9, characterized in that: The driving structure is a pneumatic deformation layer, which has a sealed deformation cavity. Inflating or deflating the deformation cavity can bend or straighten the pneumatic deformation layer; each of the variable stiffness soft claws is fixedly connected to the installation side of the base, and the end of each of the variable stiffness soft claws close to the base is a first end, and the end of each of the variable stiffness soft claws away from the base is a second end. A straight line passing through the center of the first circular trajectory and perpendicular to the installation side is a first straight line. When the pneumatic deformation layer is bent, each of the second ends is closer to the first straight line than each of the first ends.

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