Flexible clutch device based on surface buckling

Abstract

The invention discloses a flexible clutch device based on surface buckling, and belongs to the technical field of soft robots. The flexible clutch device comprises two functional layers, namely a flexible substrate and a flexible film. The flexible film is pre-bent into a periodic shape which can be mutually embedded, and the bottom surface of the film is bonded with the surface of the substrate to form a semi-clutch. External force is applied to stretch the flexible substrate of the semi-clutch, tensile deformation of the flexible substrate drives the flexible film bonded to the surface of the flexible substrate to stretch, the buckling shape of an inverted triangle is changed into a rectangle or a trapezoid, and separation of the semi-clutch from another semi-clutch subjected to tensile deformation is achieved; and the external force is released, the flexible substrate retracts to drive the shape of the flexible film adhered to the flexible substrate to recover, and the clutch is reengaged. According to the flexible clutch device, connection and separation are controlled by stretching and releasing the base, the structure is simple, the size is small, expandability is high, and the flexible clutch device is suitable for achieving connection and separation of two flexible components or two soft robots in the field of soft robots.

Description

Technical Field

[0001] The invention belongs to the technical field of soft robots and relates to a flexible clutch device based on surface buckling. Background Art

[0002] In mechanical structures, the transmission between the master and slave components, as well as the locking and unlocking of some components, often require the cooperation of a clutch. At present, in the field of soft robots, the body of a soft robot is often integral and cannot be disassembled, so when a limb of the robot is stuck or pressed by a heavy object, the soft robot cannot escape by "breaking a limb". In addition, when a soft robot loses power, it is difficult for other soft robots to effectively connect to it and drag it away. Therefore, soft robots also need a clutch to achieve the connection and separation between their limbs and body, or to achieve the connection and separation between multiple soft robots. Traditional clutches are mostly rigid structures made of metal materials, which are not only bulky, but also contrary to the original intention of the soft robot's flexibility. Therefore, it is very necessary to develop a flexible clutch suitable for soft robots. Summary of the invention

[0003] In order to realize the connection and separation function between flexible components or between soft robots, the present invention proposes a flexible clutch device based on surface bending, wherein a flexible film is pre-bent to form a periodic shape that can be interlocked with each other, and then it is adhered to a flexible substrate, and the bottom surface of the flexible film is bonded to the surface of the flexible substrate to form a half clutch, and two half clutches are combined to form a complete clutch. When an external force is applied to stretch the flexible substrate of the half clutch, the stretching deformation of the flexible substrate drives the flexible film bonded to its surface to stretch and deform, and the inverted triangle wave shape changes to a rectangle or a trapezoid, which can achieve separation from another half clutch that is also subjected to stretching deformation; when the external force is released, the flexible substrate retracts, driving the flexible film bonded thereon to restore to the periodic inverted triangle wave shape before stretching, and the connection of the two half clutches is achieved. The flexible clutch controls the connection and separation of the clutch by stretching and releasing the flexible substrate, has a simple structure, a small volume, good flexibility, and high scalability, and is suitable for the field of soft robots to achieve the connection and separation between two flexible components or two soft robots.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A flexible clutch device based on surface buckling comprises two functional layers, namely a flexible substrate and a flexible film, which are, from top to bottom, a first flexible substrate 1, a first flexible film 2, a second flexible film 3 and a second flexible substrate 4; the first flexible film 2 and the second flexible film 3 are pre-bent into periodic shapes that can be interlocked with each other, the first flexible film 2 is bonded to the lower surface of the first flexible substrate 1 to form a half clutch; the second flexible film 3 is bonded to the upper surface of the second flexible substrate 4 to form another half clutch; the two half clutches are combined to form a complete clutch device, the first flexible film 2 and the second flexible film 3 are separated by stretching and deforming the first flexible substrate 1 and the second flexible substrate 4; the first flexible film 2 and the second flexible film 3 are joined by releasing the stretching of the first flexible substrate 1 and the second flexible substrate 4.

[0006] The engagement strength of the clutch can be adjusted by regulating the elastic modulus, thickness, and size and number of the periodic shapes of the first flexible film 2 and the second flexible film 3 .

[0007] Preferably, the stretching and releasing of the first flexible substrate 1 and the second flexible substrate 4 are pneumatically implemented by inflating and deflating the flexible substrates containing the hollow chambers.

[0008] Preferably, the periodic shapes that can be interlocked with each other are inverted triangle waves or inverted trapezoids.

[0009] Preferably, the first flexible film 2 and the second flexible film 3 are made of polymer material by cutting into rectangular shapes and bending them.

[0010] Preferably, the flexible clutch devices of the same structure are arranged crosswise to achieve three-dimensional engagement.

[0011] Preferably, the first flexible film 2 and the second flexible film 3 are respectively bonded to the first flexible substrate 1 and the second flexible substrate 4 by adhesive materials. The first flexible substrate 1 and the second flexible substrate 4 are made of silicone rubber, which is soft and can easily realize extension and contraction movements by inflating and deflating the hollow chamber made of it.

[0012] The adhesive material is a silicone adhesive, which can firmly bond the silicone rubber with low surface energy and chemical inertness to the flexible film.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The clutch is realized by the surface buckling structure, which has simple structure, small volume and good flexibility.

[0015] 2. No external power is required to maintain the joint state by itself. Separation can be achieved by stretching the flexible substrate, which is easy to operate.

[0016] 3. The present invention has strong scalability and can cross-arrange the same structure to achieve bidirectional connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is the state of a flexible clutch device based on surface buckling when engaged according to the present invention;

[0019] Figure 2 It is the state of a flexible clutch device based on surface buckling when disengaged according to the present invention;

[0020] Figure 3 This is a physical diagram of a flexible clutch device based on surface buckling according to the present invention;

[0021] Figure 4 It is a line graph showing the change of tensile strength of the flexible clutch device with the thickness of the flexible film and the angle between the oblique edge and the straight edge of the flexible film;

[0022] Figure 5 It is a line graph showing the shear strength of the flexible clutch device as a function of the thickness of the flexible film and the angle between the bevel and the straight edge of the flexible film;

[0023] Figure 6 It is a schematic diagram of a flexible clutch device based on surface buckling of the present invention expanded into a cross-arranged structure;

[0024] Figure 7 This is a physical picture of a flexible clutch device based on surface buckling of the present invention expanded into a cross-arranged structure.

[0025] Description of reference numerals:

[0026] 1. First flexible substrate; 2. First flexible film; 3. Second flexible film; 4. Second flexible substrate. DETAILED DESCRIPTION

[0027] In order to illustrate the effect of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, and the preferred embodiment of the present invention is shown in the drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0028] See also Figure 1-3 As shown, the present invention provides a flexible clutch device based on surface bending, including two functional layers of a flexible substrate and a flexible film, which are, from top to bottom, a first flexible substrate 1, a first flexible film 2, a second flexible film 3, and a second flexible substrate 4; the first flexible film 2 is bonded to the lower surface of the first flexible substrate 1, and the second flexible film 3 is bonded to the upper surface of the second flexible substrate 4.

[0029] The first flexible film 2 and the second flexible film 3 can be separated by stretching and deforming the first flexible substrate 1 and the second flexible substrate 4; and the first flexible film 2 and the second flexible film 3 can be joined by releasing the stretching of the first flexible substrate 1 and the second flexible substrate 4.

[0030] As a preferred embodiment of the present invention, the first flexible film 2 and the second flexible film 3 are made of polymer materials. It should be understood that the flexible films may also be made of other flexible materials.

[0031] As a preferred embodiment of the present invention, the first flexible film 2 and the second flexible film 3 are bent to form a periodic inverted triangle wave shape. It should be understood that other shapes that can be interlocked with each other, such as an inverted trapezoid, can also be used.

[0032] As a preferred embodiment of the present invention, the first flexible substrate 1 and the second flexible substrate 4 are made of silicone rubber. It should be understood that the flexible substrates may also be made of other flexible materials.

[0033] As a preferred embodiment of the present invention, the first flexible film 2 and the second flexible film 3 are respectively bonded to the first flexible substrate 1 and the second flexible substrate 4 through the adhesive material 5 .

[0034] As a preferred embodiment of the present invention, the adhesive material is a silicone adhesive. It should be understood that the adhesive material may also be other adhesives as long as the flexible film and the flexible substrate can be firmly bonded.

[0035] As a preferred embodiment of the present invention, the engagement strength of the clutch can be adjusted by regulating the elastic modulus and thickness of the first flexible film 2 and the second flexible film 3 and the size and number of the periodic inverted triangle waves.

[0036] As a preferred embodiment of the present invention, the stretching and retraction of the first flexible substrate 1 and the second flexible substrate 4 can be achieved pneumatically by inflating and deflating the flexible substrate containing the hollow chamber.

[0037] In an embodiment of the present invention, the preparation process of the flexible substrate is as follows: pour component A and component B of silicone (Ecoflex 00-10) into a beaker at a volume ratio of 1:1, stir for 3 minutes to mix the two components evenly, then cast into a rectangular mold, cure at room temperature for 4 hours, and then demold.

[0038] like Figure 3 The figure shows a real clutch made according to the above instructions. Figure 6 and Figure 7 The clutch is made by arranging the same structure crosswise, Figure 7 This is a real picture, which can achieve bonding in two directions.

[0039] Embodiment 1:

[0040] The first flexible substrate 1 and the second flexible substrate 4 are selected to have a size of 55×15×3 mm. 3 The first flexible film 2 and the second flexible film are selected to have a size of 128.5×10 mm 2 The polyethylene terephthalate (PET) material has a thickness of 0.1 mm. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches, respectively. The two are interlocked to form a complete clutch, such as Figure 1 and Figure 3 Taking the second flexible film 3 as an example, from left to right, the side lengths of the film are arranged periodically as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the lengths of the straight sides; the angle between the straight side and the hypotenuse is 30°.

[0041] Embodiment 2:

[0042] The same first flexible film 2 and second flexible film 3 were prepared according to Example 1. The first flexible substrate 1 and second flexible substrate 4 were selected to have a size of 65×15×3 mm. 3Rectangular silicone rubber. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively, which are interlocked to form a complete clutch. Among them, taking the second flexible film 3 as an example, from left to right, the length of the triangle side is arranged periodically according to 10.5-5-9-5-10.5mm; wherein 5mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 45°. Periodic arrangement refers to the division of the rectangular film. After bending it, the angle between the straight side and the hypotenuse can vary in the range of 0° to 90°. The change in the angle will affect the length of the flexible substrate, so the length of the flexible substrate in Example 1 is different from that in Example 2.

[0043] Embodiment 3:

[0044] The same first flexible film 2 and second flexible film 3 were prepared according to Example 1. The first flexible substrate 1 and second flexible substrate 4 were selected to have a size of 70×15×3 mm. 3 Rectangular silicone rubber. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively, which are interlocked to form a complete clutch. Taking the second flexible film 3 as an example, from left to right, the length of the triangle side is periodically arranged as 10.5-5-9-5-10.5mm; 5mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 60°.

[0045] Embodiment 4:

[0046] The same first flexible substrate 1 and second flexible substrate 4 were prepared according to Example 1, and the first flexible film 2 and second flexible film were selected to have a size of 128.5×10 mm. 2 The polyethylene terephthalate (PET) material has a thickness of 0.15 mm. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively. The two are interlocked to form a complete clutch, as shown in FIG. Figure 1Taking the second flexible film 3 as an example, from left to right, the length of the triangle side is periodically arranged as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 30°.

[0047] Embodiment 5:

[0048] The same first flexible substrate 1 and second flexible substrate 4 were prepared according to Example 2, and the first flexible film 2 and second flexible film were selected to have a size of 128.5×10 mm. 2 The polyethylene terephthalate (PET) material has a thickness of 0.15 mm. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively. The two are interlocked to form a complete clutch, as shown in FIG. Figure 1 Taking the second flexible film 3 as an example, from left to right, the length of the triangle side is periodically arranged as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 45°.

[0049] Embodiment 6:

[0050] The same first flexible substrate 1 and second flexible substrate 4 were prepared according to Example 3, and the first flexible film 2 and second flexible film were selected to have a size of 128.5×10 mm. 2 The polyethylene terephthalate (PET) material has a thickness of 0.15 mm. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively. The two are interlocked to form a complete clutch, as shown in FIG. Figure 1 Taking the second flexible film 3 as an example, from left to right, the length of the triangle side is periodically arranged as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 60°.

[0051] Embodiment 7:

[0052] The same first flexible substrate 1 and second flexible substrate 4 were prepared according to Example 1, and the first flexible film 2 and second flexible film were selected to have a size of 128.5×10 mm. 2The polyethylene terephthalate (PET) material has a thickness of 0.2 mm. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively. The two are interlocked to form a complete clutch, as shown in FIG. Figure 1 Taking the second flexible film 3 as an example, from left to right, the length of the triangle side is periodically arranged as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 30°.

[0053] Embodiment 8:

[0054] The same first flexible substrate 1 and second flexible substrate 4 were prepared according to Example 2, and the first flexible film 2 and second flexible film were selected to have a size of 128.5×10 mm. 2 The polyethylene terephthalate (PET) material has a thickness of 0.2 mm. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively. The two are interlocked to form a complete clutch, as shown in FIG. Figure 1 Taking the second flexible film 3 as an example, from left to right, the length of the triangle side is periodically arranged as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 45°.

[0055] Embodiment 9:

[0056] The same first flexible substrate 1 and second flexible substrate 4 were prepared according to Example 3, and the first flexible film 2 and second flexible film were selected to have a size of 128.5×10 mm. 2 The polyethylene terephthalate (PET) material has a thickness of 0.2 mm. The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape. The first flexible film 2 and the second flexible film 3 have the same size. The bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches respectively. The two are interlocked to form a complete clutch, as shown in FIG. Figure 1Taking the second flexible film 3 as an example, from left to right, the length of the triangle side is periodically arranged as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 60°.

[0057] Embodiment 10:

[0058] The first flexible substrate 1 and the second flexible substrate 4 are selected as a cross-shaped rectangular silicone rubber, and the size of each branch is 55×15×3 mm. 3 The first flexible film 2 and the second flexible film 3 are selected to be cross-shaped polyethylene terephthalate (PET) materials, and the size of each branch is 128.5×10 mm 2 The first flexible film 2 and the second flexible film 3 are bent into a periodic inverted triangle wave shape, and the bent first flexible film 2 and the second flexible film 3 are respectively adhered to the first flexible substrate 1 and the second flexible substrate 4 to form two half clutches, which are interlocked to form a complete clutch. Figure 7 Taking the second flexible film 3 as an example, the length of the triangle side is arranged periodically as 10.5-5-9-5-10.5 mm; 5 mm is the length of the hypotenuse, and the other numbers are the length of the straight side; the angle between the straight side and the hypotenuse is 45°.

[0059] Performance testing:

[0060] A tensile test was carried out on the flexible clutch using a Wance electronic universal testing machine. The silicone rubber bases of the two fitted half-clutches were glued to a lightweight wooden base. The base was clamped by the clamp of the tensile machine to drive the clutch to stretch along the direction perpendicular to the plane of the flexible base (defined as the normal direction) and along the length direction of the flexible base (defined as the tangential direction). The maximum force before the clutch was damaged and failed was measured and then divided by the corresponding flexible base area to obtain the tensile strength and shear strength, respectively.

[0061] The relevant dimensional parameters of Examples 1-9 and the performance test results are summarized in the following table.

[0062]

[0063] Figure 4 is the change of the tensile strength of the flexible clutch with the thickness of the flexible film and the angle between the straight edge and the bevel edge. Figure 5 The shear strength of the flexible clutch changes with the thickness of the flexible film and the angle between the straight edge and the bevel. From the above examples 1-9, it can be seen that the tensile strength and shear strength of the flexible clutch increase with the increase of the thickness of the flexible film, and decrease with the increase of the angle between the straight edge and the bevel of the flexible film. Under the same conditions, the shear strength is greater than the tensile strength.

Claims

1. A flexible clutch device based on surface buckling, characterized in that: The invention comprises two functional layers, namely a flexible substrate and a flexible film, which are, from top to bottom, a first flexible substrate (1), a first flexible film (2), a second flexible film (3), and a second flexible substrate (4); the first flexible film (2) and the second flexible film (3) are pre-bent into a periodic shape that can be interlocked with each other, and the first flexible film (2) is bonded to the lower surface of the first flexible substrate (1) to form a semi-clutch; The second flexible film (3) is bonded to the upper surface of the second flexible substrate (4) to form another half clutch; the two half clutches are combined to form a complete clutch device, and the first flexible film (2) and the second flexible film (3) are separated by stretching and deforming the first flexible substrate (1) and the second flexible substrate (4); and the first flexible film (2) and the second flexible film (3) are joined by releasing the stretching of the first flexible substrate (1) and the second flexible substrate (4).

2. A flexible clutch device based on surface buckling according to claim 1, characterized in that: The engagement strength of the clutch is adjusted by regulating the thickness of the first flexible film (2) and the second flexible film (3) and the size of the periodic shape.

3. A flexible clutch device based on surface buckling according to claim 1, characterized in that: The stretching and releasing of the first flexible substrate 1 and the second flexible substrate 4 are achieved by pneumatic means, which is achieved by inflating and deflating the flexible substrates containing the hollow chambers.

4. A flexible clutch device based on surface buckling according to claim 1, characterized in that: The periodic shapes that can be interlocked with each other are inverted triangle waves or inverted trapezoids.

5. A flexible clutch device based on surface buckling according to claim 1, characterized in that: The first flexible film (2) and the second flexible film (3) are made of polymer material by cutting into rectangular shapes and bending them.

6. A flexible clutch device based on surface buckling according to claim 1, characterized in that: The flexible clutch devices of the same structure are arranged crosswise to achieve three-dimensional engagement.

7. A flexible clutch device based on surface buckling according to claim 1, characterized in that: The first flexible film (2) and the second flexible film (3) are respectively bonded to the first flexible substrate (1) and the second flexible substrate (4) via adhesive materials; the first flexible substrate (1) and the second flexible substrate (4) are made of silicone rubber.

8. A flexible clutch device based on surface buckling according to claim 7, characterized in that: The adhesive material is a silicone adhesive.

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