Folding bending flexible actuator and manufacturing method and testing system thereof

Abstract

The application provides a foldable bending type flexible driver, a manufacturing method thereof and a test system thereof, which comprises a foldable structure framework as a bearing main body, the outer side of the framework is sealed and wrapped through a flexible sealing film, and the left power plate and the right power plate of the framework extend out of the outer side of the flexible sealing film, one end of a negative pressure pipe extends into the flexible sealing film, and the other end is used for connecting a negative pressure source to provide power for the flexible driver; the framework comprises the left power plate, the right power plate, a top plate located on the upper part of the left power plate and a top plate located on the upper part of the right power plate, an upper cross beam located above the two top plates, and a lower cross beam located on the lower part of the left power plate and the right power plate; at least two vertical panels are rotatably connected between the left / right power plate and the top plate, and the number and structure parameters of the vertical panels between the left / right power plate and the top plate are the same; the driver can obtain a larger deformation amplitude and output force, and can do work in the reset stage.

Description

Technical Field

[0001] The present invention relates to the technical field of robot drive equipment applications, and in particular to a foldable, curved, flexible actuator, a manufacturing method thereof, and a testing system thereof. Background Art

[0002] Rigid actuators, such as motors and hydraulic cylinders, are widely used. However, they have many disadvantages, such as complex structures, poor safety, and limited adaptability. To address this challenge, flexible actuators have been gaining attention as alternatives to rigid actuators, and various flexible actuators have been developed over the past decade. These actuators are composed of flexible materials and possess inherent flexibility and adaptability. To date, flexible actuators have been used to drive flexible robots.

[0003] From a motion perspective, there are two main types of flexible actuators: linear actuators and flexure actuators. Linear actuators can produce linear motion and have seen significant progress in their deformation amplitude, output force, and operating modes. Flexure actuators, on the other hand, can produce bending motion and are primarily driven by electric actuation and fluid dynamics.

[0004] Typical electrically driven flexible actuators are made of shape memory alloys (SMA), dielectric elastomers (DE), or ionic polymer-metal composites (IPMC). SMA actuators have slow response speeds. DE actuators require high drive voltages and suffer from poor stability. IPMCs can produce large deformations but exert very low force.

[0005] Compared to electric flexible actuators, fluid-driven soft bending actuators offer superior performance in terms of response speed, deformation, and output force, making them a research hotspot in recent years. Most existing soft bending actuators are driven by positive-pressure fluids, which can achieve considerable bending deformation and output force. However, they require a fairly high input pressure, which can lead to safety issues. In contrast, negative-pressure actuators are highly valuable because they can operate more safely. Unfortunately, few flexible bending actuators are driven by negative-pressure fluids. Furthermore, existing negative-pressure-driven bending actuators often do not perform satisfactorily.

[0006] Regardless of the materials and structures used, these bending actuators share a common characteristic: they operate in only one direction. Some actuators use negative pressure fluid to facilitate resetting, but this struggles to effectively perform work during the resetting phase. Furthermore, some actuators generate bending motion by connecting multiple cavities in parallel, but this requires controlling the actuator's motion across multiple channels, which is not easy to do.

[0007] Overall, existing flexible bending actuators have made substantial progress in deformation amplitude. However, unidirectional operation and low torque output severely limit the application of most such actuators.

[0008] On July 21, 2022, the inventor applied for a patent for an invention titled "Flexible actuator based on muscle cross-bridge structure, its manufacturing method, and testing system." The invention comprises a foldable skeleton as a load-bearing body, the outer side of the skeleton is sealed and wrapped by a flexible sealing membrane, and the left and right power plates of the skeleton extend outward from the outer side of the flexible sealing membrane. One end of the negative pressure tube extends into the flexible sealing membrane, and the other end is used to connect to a negative pressure source to provide power for the flexible actuator; the skeleton includes a left power plate, a right power plate, a top plate located above the left and right power plates, and a bottom plate located below the left and right power plates; at least two vertical panels are rotatably connected between the left / right power plates and the top / bottom plates, and the number and structural parameters of the vertical panels between the left / right power plates and the top / bottom plates are the same; two side plates are rotatably connected between the two sides of the bottom plate and the top plate, and the two side plates on the same side can also be rotatably connected. The actuator can achieve good force retention and a large output force. However, the actuator cannot be reset actively and requires the assistance of external conditions to reset. Summary of the Invention

[0009] The purpose of the present invention is to provide a foldable bending flexible actuator and its manufacturing method and testing system, so as to solve the problems in the prior art that the bending flexible actuator has a small output torque and can only perform work in one direction.

[0010] In order to achieve the above objectives, the present invention adopts the following technical solutions.

[0011] A foldable, bendable, flexible actuator comprises a deformable frame as a supporting body. The outer side of the deformable frame is sealed and wrapped by a flexible sealing membrane. The left and right power plates of the deformable frame extend outwardly from the outer side of the flexible sealing membrane. One end of a negative pressure tube extends into the flexible sealing membrane, and the other end is used to connect to a negative pressure source to provide power for the flexible actuator. The deformable frame includes a left power plate, a right power plate, a left top plate located above the left power plate, a right top plate located above the right power plate, an upper crossbeam located above the two top plates, and a lower crossbeam located below the left and right power plates. At least two vertical panels are rotatably connected between the left / right power plates and their upper top plates, and each of the vertical panels has identical structural parameters. The upper crossbeam and the lower crossbeam are made of elastically deformable materials, while the left and right power plates are made of rigid materials. Furthermore, the upper crossbeam and the lower crossbeam are made of the same material.

[0012] The folding curved flexible driver further comprises a left elastic substrate and a right elastic substrate, the left elastic substrate is formed by folding into an upper left horizontal plate, a lower left horizontal plate and at least two vertical face plates between the upper left horizontal plate and the lower left horizontal plate, a left top plate is connected to the upper left horizontal plate, and a left power plate is connected to the lower left horizontal plate; the right elastic substrate is formed by folding into an upper right horizontal plate, a lower right horizontal plate and at least two vertical face plates between the upper right horizontal plate and the lower right horizontal plate, a right top plate is connected to the upper right horizontal plate, and a right power plate is connected to the lower right horizontal plate.

[0013] The upper left horizontal plate of the left elastic substrate is connected to the left top plate by pasting, and the lower left horizontal plate of the left elastic substrate is connected to the left power plate by pasting; the upper right horizontal plate of the right elastic substrate is connected to the right top plate by pasting, and the lower right horizontal plate of the right elastic substrate is connected to the right power plate by pasting.

[0014] The application further provides a manufacturing method of the folding curved flexible driver, and the method comprises the following steps:

[0015] (1) according to the designed size, the elastic sheet is cut into an upper cross beam and a lower cross beam by a laser cutting machine for standby use;

[0016] (2) a hard sheet is cut into a left power plate, a right power plate, a left top plate and a right top plate by a laser cutting machine for standby use;

[0017] (3) the elastic sheet is cut into a left / right elastic substrate with a cutting seam by a laser cutting machine for standby use;

[0018] (4) the left / right elastic substrate is folded into a designed structure along the cutting seam to have an upper horizontal plate, a lower horizontal plate and at least two vertical face plates between the upper horizontal plate and the lower horizontal plate, and each part can rotate relative to the cutting seam;

[0019] (5) the left power plate and the left top plate are respectively pasted on specific positions of the left elastic substrate by glue, and the right power plate and the right top plate are respectively pasted on specific positions of the right elastic substrate by glue;

[0020] (6) the two ends of the upper cross beam are respectively pasted on the left top plate and the right top plate by glue, the two ends of the lower cross beam are respectively pasted on the left power plate and the right power plate by glue to obtain a skeleton of the driver, then a flexible sealing film is sealed and a negative pressure pipe is assembled to obtain the flexible driver.

[0021] Furthermore, during the manufacturing process, it is assumed that the deformed upper and lower beams are both approximately arc-shaped, and the ends of the arcs are tangent to the adjacent top plate or left / right power plates. S1 and S2 are the lengths of the elastically deformable portions of the lower and upper beams, respectively. θ is the bending angle of the actuator. d is the shortest distance between the upper and lower beams after the vertical panels on both sides simultaneously reach their maximum motion amplitude. L is the distance between the rotation axes at the two ends of the vertical panels. Δ is the difference between the length of the upper beam S2 and the length of the lower beam S1.

[0022] According to formula (1), the above design parameters are optimized to make the actuator produce the ideal bending angle θ;

[0023]

[0024] The present invention further provides a testing system for the foldable, bendable flexible actuator, comprising a tension and pressure sensor, a camera, a vacuum pressure gauge, a vacuum proportional valve, an electromagnetic reversing valve, a pressure reducing valve, and a vacuum pump; the left power plate is fixed to a bracket, the camera is mounted on a base via a camera bracket and is located directly above the actuator; the dial with a scale is mounted on the base and is located directly below the actuator, and the center position of the dial scale coincides with the center position of the lower crossbeam of the actuator; the front end of the tension and pressure sensor contacts the right power plate via a small bolt for testing the output force of the actuator; the tension and pressure sensor is mounted on an adjustable bracket, which is mounted on a base, and the position and posture of the tension and pressure sensor can be adjusted by the adjustable bracket to measure the output force of the actuator at different bending angles; the vacuum pump is connected to the negative pressure pipe of the flexible actuator via a vacuum pressure gauge, a vacuum proportional valve, an electromagnetic reversing valve, and a pressure reducing valve, and the position change of the right power plate of the actuator relative to the dial is tested by the camera to obtain the bending angle of the flexible actuator; the pressure of the flexible actuator is generated by the vacuum pump through the vacuum proportional valve and the electromagnetic valve.

[0025] Beneficial Effects: Due to its skeletal structure, which combines upper and lower beams with two parallelogram mechanisms on either side, the actuator of the present invention can generate bending motion and perform work during the reset phase. Furthermore, the actuator of the present invention exhibits a large deformation amplitude and output force. Test results show that the actuator manufactured using the assembly process generates a maximum end force of 9.6N, corresponding to a maximum torque of 1103N.mm, and achieves a maximum bending angle of 138 degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a complete structural diagram of the driver.

[0027] Figure 2 It is a schematic diagram of the driver assembly skeleton structure.

[0028] Figure 3 It is a schematic diagram of the assembled skeleton structure when the driver is deformed.

[0029] Figure 4 It is a structural diagram of the driver skeleton made using the patch process.

[0030] Figure 5 Schematic diagram of the structure of the elastic substrate, where (a) is the initial structure of the left / right elastic substrate with slits, (b) is the structure after the left elastic substrate is folded, and (c) is the structure after the right elastic substrate is folded.

[0031] Figure 6 It is a structural diagram of the flexible actuator test system. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0033] The present invention introduces a specific embodiment by taking a curved flexible actuator having an assembled frame as an example.

[0034] like Figure 1 As shown, the bending flexible actuator of the present invention includes a skeleton structure, a sealing membrane 3 and a negative pressure tube 2.

[0035] like Figure 2 As shown, the skeleton structure of the bending flexible actuator with an assembled skeleton of the present invention includes four vertical panels, one left power plate, one right power plate, one left top plate and one right top plate, one upper crossbeam and one lower crossbeam. The lower ends of the two vertical panels 5 on the left are respectively connected to the left power plate 1, and the upper ends of the two vertical panels 5 on the left are respectively connected to the left top plate 8-1. The lower ends of the two vertical panels 5 on the right are respectively connected to the right power plate 4, and the upper ends of the two vertical panels 5 on the right are respectively connected to the right top plate 8-2. The upper parts of the left top plate 8-1 and the right top plate 8-2 are fixedly connected to the upper crossbeam 7.

[0036] The two adjacent vertical panels 5 on the left, the left power plate 1, and the left top plate 8-1 form a parallelogram mechanism, while the two adjacent vertical panels 5 on the right, the right power plate 4, and the right top plate 8-2 form a parallelogram mechanism. These two parallelogram mechanisms ensure that the left power plate 1 always remains parallel to the left top plate 8-1, and the right power plate 4 always remains parallel to the right top plate 8-2.

[0037] The upper crossbeam 7 and the lower crossbeam 6 are used to bear the external pressure load, and the four vertical panels 5 are used to transmit the load. Through the movement of the two parallelogram mechanisms, the length change patterns of the upper crossbeam 7 and the lower crossbeam 6 are inconsistent. Under the synergistic effect of the two, the upper crossbeam 7 and the lower crossbeam 6 eventually undergo differentiated bending deformation to offset the external pressure load.

[0038] The driver of the present invention is driven by negative pressure fluid. A negative pressure tube 2 is provided at the connection between the skeleton structure and the sealing membrane 3. The negative pressure tube 2 connects the driver cavity with the external environment.

[0039] When the external pressure load decreases, the upper crossbeam 7 and the lower crossbeam 6 recover a part of their initial shape under their own elasticity. At this stage, the driver recovers its initial state and can do work externally.

[0040] To analyze the deformation of the actuator during motion, we assume that the deformed upper and lower beams are approximately arc-shaped, with the ends of the arcs tangent to the adjacent top plate or left / right power plates. S1 and S2 are the lengths of the elastically deformable portions of the lower and upper beams, respectively. θ is the bending angle of the actuator. d is the shortest distance between the upper and lower beams after the vertical panels on both sides reach their maximum motion amplitude simultaneously. L is the distance between the rotating axes of the vertical panels.

[0041] Analysis shows that the relationship between the length difference Δ=S1-S2 between the lower beam and the upper beam and the ideal bending angle θ generated by the driver is:

[0042]

[0043] The present invention also provides a method for manufacturing the foldable, curved, flexible actuator, comprising the following steps:

[0044] (1) According to the design size, the elastic sheet is cut into upper and lower beams using a laser cutting machine for standby use;

[0045] (2) Cut the hard thin plate into the left power plate, the right power plate, the left top plate and the right top plate using a laser cutting machine for later use;

[0046] (3) Cutting the elastic sheet into left / right elastic substrates with slits using a laser cutting machine for later use;

[0047] (4) folding the left / right elastic substrate along the slit into a designed structure having an upper horizontal plate, a lower horizontal plate, and at least two vertical panels located between the upper horizontal plate and the lower horizontal plate, wherein the parts can rotate relative to each other along the slit;

[0048] (5) Glue the left power plate and the left top plate to specific positions on the left elastic base plate, and glue the right power plate and the right top plate to specific positions on the right elastic base plate;

[0049] (6) Glue the two ends of the upper crossbeam to the left top plate and the right top plate respectively, and glue the two ends of the lower crossbeam to the left power plate and the right power plate respectively to obtain the skeleton of the driver. Then seal it with a flexible sealing film and assemble the negative pressure tube to obtain the flexible driver.

[0050] The upper left horizontal plate of the left elastic base and the left top plate are connected by adhesive bonding, and other connection methods such as bolt connection, riveting, etc. shall not be used to avoid affecting the movement of the parallelogram mechanisms on the left and right sides.

[0051] like Figure 5 As shown, the foldable bending flexible actuator of the present invention also includes a left elastic substrate 21 and a right elastic substrate 22, both of which are obtained by folding the initial structure 20 of the left / right elastic substrate with a slit, and the left elastic substrate 21 is formed by folding to form an upper left horizontal plate, a lower left horizontal plate and at least two vertical panels located between the upper left horizontal plate and the lower left horizontal plate, the upper left horizontal plate is connected to the left top plate 8-1, and the lower part of the lower left horizontal plate is connected to the left power plate 1; the right elastic substrate 22 is formed by folding to form an upper right horizontal plate, a lower right horizontal plate and at least two vertical panels located between the upper right horizontal plate and the lower right horizontal plate, the upper right horizontal plate is connected to the right top plate 8-2, and the lower part of the lower right horizontal plate is connected to the right power plate 4.

[0052] The upper left horizontal plate of the left elastic base 21 and the left top plate 8-1 are connected by gluing, and the lower left horizontal plate of the left elastic base 21 and the left power plate 1 are connected by gluing; the upper right horizontal plate of the right elastic base 22 and the right top plate 8-2 are connected by gluing, and the lower right horizontal plate of the right elastic base 22 and the right power plate 4 are connected by gluing.

[0053] In addition, the driver of the present invention can also be manufactured by assembly, wherein each component is first manufactured separately, and then all the components are assembled to obtain the driver frame. The driver frame manufactured by the assembly process is called an assembled frame.

[0054] The actuator is produced by sealing the skeleton structure produced using the above process with a flexible, airtight film of high toughness. The actuator of the present invention is driven by a negative pressure fluid and requires a negative pressure source to provide power. During operation, the flexible sealing film transmits pressure to the upper and lower crossbeams of the skeleton and the two vertical panels at the left and right ends. This pressure is then transmitted through two parallelogram mechanisms to drive the actuator's movement.

[0055] The driver is manufactured by assembly. The basic parameters of different driver frames are shown in the following table:

[0056]

[0057] Among them, L1 represents the distance between the two rotating shafts at the upper and lower ends of the vertical panel 5, L2 represents the distance between the rotating shafts connecting the two vertical panels in the left power board 1 or the right power board 4 or the top board 8, b represents the total width of the driver frame, L all Represents the total length of the drive frame.

[0058] Different manufacturing processes can be used to manufacture different actuator frames, thereby obtaining actuators with different characteristics. The present invention uses a curved flexible actuator including an assembled frame as a representative to introduce the motion process and embodiments of the actuator.

[0059] The motion of the bending flexible actuator, refer to Figure 3 .

[0060] When driven by negative pressure fluid, the upper crossbeam 7, lower crossbeam 6, and two vertical panels 5 at each end bear the external pressure load, with the pressure direction perpendicular to the contact surface and toward the inside of the actuator cavity. This causes the two vertical panels 5 on the left to rotate clockwise around the left power plate 1, and the two vertical panels 5 on the right to rotate counterclockwise around the right power plate 4. This simultaneously drives the left top plate 8-1 and the right top plate 8-2 to move horizontally.

[0061] like Figure 3 As shown, during the negative pressure fluid drive process, the left and right quadrilateral mechanisms tend to move toward the center, shortening the distance between the left top plate 8-1 and the right top plate 8-2 or lengthening the distance between the left power plate 1 and the right power plate 4. In this case, the upper crossbeam 7 connecting the left and right top plates and the lower crossbeam 6 connecting the left and right power plates become obstacles to movement because both the upper and lower crossbeams are inextensible.

[0062] Considering that the upper and lower crossbeams are made of the same material and have the same width, but the lower crossbeam 6 is longer than the upper crossbeam 7, the lower crossbeam 6 has a smaller stiffness than the upper crossbeam 7. Under the external pressure generated by the negative pressure fluid drive, the lower crossbeam 6 is the first to sag inward. Due to the structural characteristics of the parallelogram structure, the left power plate 1 and the left top plate 8-1 remain parallel, and the right power plate 4 and the right top plate 8-2 remain parallel during movement. As a result, as the lower crossbeam 6 sags inward, it drives the left and right power plates at both ends to rotate relative to each other. This, in turn, drives the left and right top plates to rotate relative to each other synchronously through the quadrilateral mechanisms on both sides, and the direction of relative rotation of the left and right top plates is the same as that of the left and right power plates. Furthermore, this causes the upper crossbeam 7 connected to the left and right top plates to bend and deform in the same direction as the lower crossbeam 6. The forces generated by the elastic deformation of the upper and lower crossbeams 7 and 6 interact with the external pressure to maintain the actuator's balance. As the upper cross beam 7 and the lower cross beam 6 are bent and deformed, relative movement occurs between the left power plate 1 and the right power plate 4, which manifests as the entire driver bending.

[0063] In summary, as driven by the negative pressure fluid, the skeleton deforms in a unique way.

[0064] When the driving negative pressure decreases, the external load on the upper beam 7 and the lower beam 6 decreases, and their deformation degree decreases. Under the action of their own elasticity, they reset, driving the relative movement between the left power plate 1 and the right power plate 4, which manifests as the overall reset of the driver.

[0065] The performance of the drive was tested on a test system. Figure 6 , structure 14 is the driver of the present invention, the left end of the driver 14 is fixed to the base 9 through the bracket 10; the camera 12 is installed on the base 9 through the camera bracket 11, and is located directly above the driver 14; the dial 13 with a scale is installed on the base 9, and is located directly below the driver 14, and the center position of the scale of the dial 13 coincides with the center position of the lower crossbeam of the driver 14; the tension and pressure sensor 16 is installed on the horizontal adjustment bracket 17, the horizontal adjustment bracket 17 is installed on the rotation adjustment bracket 18, the rotation adjustment bracket 18 is installed on the angle adjustment bracket 19, and the angle adjustment bracket 19 is installed on the base 9 and can be manually adjusted relative to the base 9; the front end of the tension and pressure sensor 16 is in contact with the right power plate of the driver 14 through a bolt 15, for testing the output force of the driver 14; the position and posture of the tension and pressure sensor 16 can be adjusted by the angle adjustment bracket 19, the rotation adjustment bracket 18, and the horizontal adjustment bracket 17 to measure the terminal output force of the driver 14 at different bending angles;

[0066] The vacuum pump is connected with the negative pressure pipe of the flexible driver through a vacuum pressure gauge, a vacuum proportional valve, an electromagnetic reversing valve and a pressure reducing valve, the pose change of the right power plate of the driver relative to the dial is tested through the camera, and then the bending angle of the flexible driver is obtained; the pressure of the flexible driver is generated by the vacuum pump through the vacuum proportional valve and the electromagnetic valve, and the above-mentioned devices form a complete performance test system.

[0067] During the test, the vacuum pump, the vacuum proportional valve and the electromagnetic valve adjust the pressure in the driver through the air pipe.

[0068] Under the driving of the negative pressure fluid, the driver generates bending motion. When the driver bends, the left power plate 1 and the right power plate 4 of the driver move relatively, drive the whole driver to bend, and output the end force or torque. The bending angle can be measured by the camera 12 and the dial 13, and the output force can be measured by the tension and pressure sensor 16. Thus, the relationship among the pressure, the angle and the output force during the bending motion of the driver can be obtained, and the performance test of the driver is completed.

[0069] Taking the bending type flexible driver containing the assembled skeleton as an example, the performance parameters of the driver made of different upper and lower beam materials obtained by the performance test system are shown in the following table:

[0070]

[0071] The test results show that the driver has a large deformation range and output force, and can do work in the reset stage. Among them, the driver made of carbon fiber plates as the upper and lower beam materials can generate a maximum end force of 9.6N, and the corresponding maximum torque is 1103N.mm; the driver made of PVC plates as the upper and lower beam materials can reach a maximum bending angle of 138 degrees.

[0072] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit the scope of protection, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: after reading the present application, those skilled in the art can make various changes, modifications or equivalent replacements to the specific embodiments of the application, but these changes, modifications or equivalent replacements are all within the scope of protection of the claims of the application.

Claims

1. A foldable bending flexible actuator, characterized in that: The flexible driver has a deformable skeleton as a bearing body, the outer side of the deformable skeleton is sealed and wrapped by a flexible sealing membrane, and the left power plate and the right power plate of the deformable skeleton extend outward from the outer side of the flexible sealing membrane, one end of the negative pressure tube extends into the flexible sealing membrane, and the other end is used to connect the negative pressure source to provide power for the flexible driver; the deformable skeleton includes a left power plate, a right power plate, a left top plate located on the upper part of the left power plate and a right top plate located on the upper part of the right power plate, as well as an upper crossbeam located above the two top plates, and a lower crossbeam located below the left power plate and the right power plate; at least two vertical panels are rotatably connected between the left and right power plates and the top plates above them, and the structural parameters of each vertical panel are the same; the upper crossbeam and the lower crossbeam are made of elastic deformable materials, and the left power plate and the right power plate are made of rigid materials; S1 and S2 are the lengths of the elastically deformable parts of the lower crossbeam and the upper crossbeam, respectively. The length of the elastically deformable portion of the upper crossbeam is shorter than the length of the elastically deformable portion of the lower crossbeam. The length of the variable section is the section between the two middle vertical panels.

2. The foldable bending flexible actuator according to claim 1, characterized in that: The foldable bending flexible actuator also includes a left elastic substrate and a right elastic substrate, wherein the left elastic substrate is folded to form an upper left horizontal plate, a lower left horizontal plate, and at least two vertical panels located between the upper left horizontal plate and the lower left horizontal plate, the upper left horizontal plate is connected to the left top plate, and the lower part of the lower left horizontal plate is connected to the left power plate; the right elastic substrate is folded to form an upper right horizontal plate, a lower right horizontal plate, and at least two vertical panels located between the upper right horizontal plate and the lower right horizontal plate, the upper right horizontal plate is connected to the right top plate, and the lower part of the lower right horizontal plate is connected to the right power plate.

3. The foldable bending flexible actuator according to claim 2, characterized in that: The upper left horizontal plate of the left elastic base and the left top plate are connected by gluing, and the lower left horizontal plate of the left elastic base and the left power plate are connected by gluing; the upper right horizontal plate of the right elastic base and the right top plate are connected by gluing, and the lower right horizontal plate of the right elastic base and the right power plate are connected by gluing.

4. The foldable bending flexible actuator according to claim 1, characterized in that: The upper and lower crossbars are made of the same material.

5. A method for manufacturing the foldable, bendable flexible actuator according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: (1) According to the design size, use a laser cutting machine to cut the elastic sheet into upper and lower beams for standby use; (2) Use a laser cutting machine to cut the hard thin plate into the left power plate, right power plate, left top plate and right top plate for standby use; (3) Cut the elastic sheet into left / right elastic substrates with slits using a laser cutting machine for later use; (4) Folding the left / right elastic substrate along the slit into a designed structure having an upper horizontal plate, a lower horizontal plate, and at least two vertical panels located between the upper horizontal plate and the lower horizontal plate, wherein each part can rotate relative to the other along the slit; (5) Glue the left power plate and the left top plate to the specific positions of the left elastic base plate, and glue the right power plate and the right top plate to the specific positions of the right elastic base plate; (6) Glue the two ends of the upper crossbeam to the left top plate and the right top plate respectively, and glue the two ends of the lower crossbeam to the left power plate and the right power plate respectively to obtain the skeleton of the driver. Then seal it with a flexible sealing film and assemble the negative pressure tube to obtain the flexible driver.

6. The method for manufacturing the foldable bending flexible actuator according to claim 5, characterized in that: During the production process, it is assumed that the deformed upper and lower beams are approximately arc-shaped, and the two ends of the arc are tangent to the adjacent top plate or left / right power plate. S1 and S2 are the lengths of the elastically deformable parts of the lower and upper beams, respectively. θ is the bending angle of the actuator, d is the shortest distance between the upper and lower beams after the vertical panels on both sides reach their maximum movement amplitude at the same time, and L is the distance between the two ends of the vertical panel’s axis. is the difference between the upper beam length S2 and the lower beam length S1; The above design parameters are optimized according to formula (1) to make the actuator produce the ideal bending angle θ: (1)。 7. A testing system for the foldable bending flexible actuator according to any one of claims 1 to 4, characterized in that: The test system includes a tension and pressure sensor, a camera, a vacuum pressure gauge, a vacuum proportional valve, an electromagnetic reversing valve, a pressure reducing valve, and a vacuum pump; the left power board is fixed on the bracket, the camera is mounted on the base through the camera bracket, and is located directly above the driver; the dial with a scale is mounted on the base, and is located directly below the driver, and the center position of the dial scale coincides with the center position of the lower crossbeam of the driver; the front end of the tension and pressure sensor contacts the right power board through a small bolt for testing the output force of the driver; the tension and pressure sensor is mounted on an adjustable bracket, and the adjustable bracket is mounted on the base. The position and posture of the tension and pressure sensor can be adjusted through the adjustable bracket to measure the output force of the driver at different bending angles; the vacuum pump is connected to the negative pressure pipe of the flexible driver through the vacuum pressure gauge, vacuum proportional valve, electromagnetic reversing valve, and pressure reducing valve, and the position change of the right power board of the driver relative to the dial is tested through the camera to obtain the bending angle of the flexible driver; the pressure of the flexible driver is generated by the vacuum pump through the vacuum proportional valve and the electromagnetic valve.

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