A parallel bending soft actuator

Abstract

The present invention discloses a parallel bending soft actuator comprising at least two soft actuator components, the bottom surface of one soft actuator component being connected to the bottom surface of another soft actuator component. The soft actuator components comprise a connection port, a base structure, and a wavy non-rotating structure sequentially connected along a first direction, with a cavity formed between the connection port, the base structure, and the wavy non-rotating structure. The first direction is parallel to the axial direction of the soft actuator components. The parallel bending soft actuator of the present invention can achieve greater rigidity and output force at a given air pressure and is easy to manufacture.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible robot modules, and in particular to a parallel bending soft actuator. Background Art

[0002] At present, the number of patients with hand disabilities caused by stroke, cerebral hemorrhage, cerebral infarction, cerebral thrombosis, cerebral palsy, burns, scalds and other types of accidents in China is gradually increasing each year. Its symptoms are mostly manifested as hand twitching, spasms, weak grasping, inability to stretch normally and "hawk hook hand". Hand rehabilitation needs to be gradual, and hand rehabilitation equipment is usually used for rehabilitation training. The key to hand rehabilitation equipment is the finger part. Existing mechanical grippers often use rigid structures, which face problems such as damage to the grasped object when grasping the object and high operating noise. Therefore, improvement is urgently needed, and soft actuators (also called soft robots) are a new research direction.

[0003] In recent years, with the emergence of new materials and the improvement of processing and manufacturing technology, a wave of soft actuator research has been set off worldwide. Soft robots are a new approach to robotics research that can be applied to many fields. Inspired by nature, researchers have begun to explore the design and control of soft robots made of flexible materials.

[0004] However, the soft actuator structure in the prior art usually has the following problems: it can only bend in one direction, the tensile force caused by reverse bending is small, and the load-bearing capacity is poor; the expansion size of the soft actuator itself increases with the increase of air pressure. When the expansion is too large, the operation of the soft actuator will be restricted by itself; when a load is applied, the stress distribution inside the structure will be uneven, there will be local stress concentration, and the service life of the soft actuator will not be long; radial expansion reduces the bending conversion efficiency; the manufacturing process is complicated and cannot be formed as a whole; and a large load is required to produce a large deformation. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a parallel bending soft actuator, which is used to solve the technical problems in the prior art that when the soft actuator is loaded, the stress distribution inside the structure will be uneven, there will be local stress concentration, the soft actuator will have a short service life, radial expansion will reduce the bending conversion efficiency, the manufacturing process is complicated, it cannot be formed as a whole, the reverse force generated during stretching is small, the bearing capacity is poor, and a large load is required to produce a large deformation.

[0006] To achieve the above and other related objectives, the present invention provides a parallel bending soft actuator, comprising:

[0007] At least two soft actuation components, the bottom surface of one soft actuation component being connected to the bottom surface of another soft actuation component;

[0008] In which, the soft actuator component includes a connecting port, a base structure and a wavy non-rotating body structure connected in sequence along a first direction, a cavity structure is formed between the connecting port, the base structure and the wavy non-rotating body structure, and the first direction is parallel to the axial direction of the soft actuator component.

[0009] In an optional embodiment, the parallel bending soft actuator includes a pair of symmetrically arranged soft actuator components, and the bottom surface of one soft actuator component is arranged opposite to the bottom surface of the other soft actuator component.

[0010] In an optional embodiment, the parallel bending soft actuator further includes an intermediate connecting surface, and the bottom surface of one soft actuator component is connected to the bottom surface of another soft actuator component via the intermediate connecting surface.

[0011] In an optional embodiment, the intermediate connecting portion includes a corrugated surface or a flat surface.

[0012] In an optional embodiment, the parallel bending soft actuator is made of elastic material.

[0013] In an optional embodiment, the parallel bending soft actuator is integrally formed.

[0014] In an optional embodiment, the soft actuation component further includes a fingertip structure, wherein the fingertip structure is connected to an end of the wave-shaped non-rotating structure away from the base structure.

[0015] In an optional embodiment, the cavity of the root structure is trumpet-shaped, and the wall thickness of the root structure is greater than the wall thickness of other parts of the soft actuator component.

[0016] In an optional embodiment, the parallel bending soft actuator includes an intermediate connecting body and three soft actuator components uniformly arranged circumferentially around the intermediate connecting body, and the bottom surface of each soft actuator component is connected to the side wall of the intermediate connecting part.

[0017] In an optional embodiment, the parallel bending soft actuator further includes a middle hole penetrating the middle connecting portion along the first direction.

[0018] In an optional embodiment, the top surface of the wavy non-rotating structure is corrugated, the bottom surface of the wavy non-rotating structure is flat or corrugated, and the wavy non-rotating structure includes crest structures and trough structures alternately arranged along the first direction.

[0019] In an optional embodiment, the width of the peak structure in the first direction becomes smaller as it moves away from the bottom surface of the soft actuator component.

[0020] In an optional embodiment, on the side of the soft actuating component, the distance between the contour line of the adjacent trough structure and the contour line of the crest structure tends to increase as it moves away from the bottom surface of the soft actuating component.

[0021] A parallel bending soft actuator of the present invention includes a pair of soft actuator components, namely an upper soft actuator component and a lower soft actuator component. The bottom surfaces of the two soft actuator components are directly symmetrically connected or symmetrically connected through an intermediate connecting surface. When a load is applied to the parallel bending soft actuator of the present invention, the stress distribution inside the structure is uniform, the stress concentration is small, and the service life is long; and this structure adopts a parallel symmetrical structure, has deformation coordination, and can produce larger deformation under smaller loads.

[0022] The parallel bending soft actuator of the present invention, which includes a pair of symmetrically arranged soft actuator components, is made of elastic material. When used as the finger part of a hand rehabilitation device, the hand can be bent and stretched to different degrees by adjusting the pressure of the fluid. At the same time, it can also generate a large pulling force when performing hyperextension rehabilitation on the fingers. It will not produce rigid constraints and pressure on the blood vessels, muscles, etc. of the hand, and there will be no discomfort when used for a long time.

[0023] Another parallel bending soft actuator of the present invention includes an intermediate connector and three or more soft actuator components uniformly arranged circumferentially around the intermediate connector. The flexible movement of the three-dimensional soft arm in space is achieved through the combination of multiple modules, and it can move in a small space. It is helpful for search and rescue work in a small space caused by earthquakes, can be used for laparoscopic surgery, and can be used as a claw that can grab conches, shells and other aquatic products underwater. This structure can, for example, reduce the stiffness of the intermediate connector by setting an intermediate hole in the intermediate connector to increase the deformation of the parallel bending soft actuator.

[0024] The parallel bending soft actuator of the present invention has a simple manufacturing process, does not require pasting, and can be integrally formed in one go.

[0025] The parallel bending soft actuator of the present invention increases the bottom width of the trough structure in the radial direction while ensuring the same bending deformation, and on the side of the soft actuator component, the distance between the contour line of the adjacent trough structure and the contour line of the peak structure tends to increase as it moves away from the bottom surface of the soft actuator component as a whole, thereby increasing the overall cross-sectional area of ​​the trough structure. This not only improves the overall strength and rigidity of the parallel bending soft actuator, but also improves the lateral bending resistance of the soft actuator component. At the same time, this design can also improve the feasibility of demolding and realize the overall molding of the mold.

[0026] The peak structure of the parallel bending soft actuator of the present invention has an increasingly larger axial width near the bottom surface. Under the condition of the same bending deformation capability, the overall strength and stiffness of the parallel bending soft actuator are improved, especially the lateral bending resistance of the soft actuator assembly is improved.

[0027] The parallel bending soft actuator of the present invention has a larger deformation of the crest structure, while the bottom deformation of the trough structure is smaller, which complies with the principle of deformation coordination during inflation and deflation.

[0028] The soft actuating component of the parallel bending soft actuator of the present invention adopts a completely hollow structure, which can be produced by a mold and is easy to demould, and can also be manufactured by methods such as 3D printing.

[0029] The overall structure of the parallel bending soft actuator of the present invention has an optimal height-to-width ratio, and can have a greater gripping force when used as a claw to perform actions such as gripping.

[0030] The parallel bending soft actuator of the present invention can generate a large force whether bending or stretching, and can bear a large load.

[0031] The parallel bending soft actuator of the present invention has an appropriate air pressure-deformation relationship during the bending deformation process, and reduces unnecessary expansion during the deformation process.

[0032] The parallel bending soft actuator of the present invention adopts an integral molding structure and does not need to distinguish the length and position of the knuckle joints of different people when used as the finger part of a hand rehabilitation device.

[0033] The deformation of the parallel bending soft actuator of the present invention is mainly caused by the change of the angle between adjacent wave peaks, rather than by the expansion and extrusion deformation of the side surfaces on both sides of the wave peaks.

[0034] The parallel bending soft actuator of the present invention can also be used as a bionic gripper to realize actions such as grasping, holding and pulling. The grasping force can be changed according to the weight of the target object without causing damage to the grasped object.

[0035] The parallel bending soft actuator of the present invention can also be used as an actuator, as a driving unit.

[0036] The parallel bending soft actuator of the present invention has a simple and compact structure, is easy to manufacture, and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the three-dimensional structure of a parallel bending soft actuator of the present application.

[0038] Figure 2 This is a schematic diagram of a half-section three-dimensional structure of a parallel bending soft actuator of the present application.

[0039] Figure 3 This is a cross-sectional schematic diagram of a parallel bending soft actuator of the present application.

[0040] Figure 4 This is a right view of a parallel bending soft actuator of the present application.

[0041] Figure 5 This is a cross-sectional view of a parallel bending soft actuator of the present application along the maximum cross-section of the wave crest structure.

[0042] Figure 6 This is another cross-sectional view of a parallel bending soft actuator of the present application along the maximum cross-section of the wave crest structure.

[0043] Figure 7 This is a schematic structural diagram of another parallel bending soft actuator of the present application.

[0044] Figure 8 This is a schematic structural diagram of the third parallel bending soft actuator of this application.

[0045] Figure 9 This is a schematic structural diagram of the fourth parallel bending soft actuator of this application.

[0046] Component number description

[0047] 1 Upper soft actuator assembly

[0048] 11 Upper fingertip structure

[0049] 12 Upper peak structure

[0050] 121 Upper peak cavity

[0051] 12a Wave crest contour line

[0052] 13 Upper trough structure

[0053] 131 Upper trough cavity

[0054] 13a Trough contour line

[0055] 14 Upper foundation structure

[0056] 141 Upper foundation cavity

[0057] 15 Upper connection port

[0058] 151 upper interface through hole

[0059] 2 Lower soft actuator assembly

[0060] 21 Lower fingertip structure

[0061] 22 Lower peak structure

[0062] 221 Lower peak cavity

[0063] 23 Lower trough structure

[0064] 231 Lower trough cavity

[0065] 24 Lower foundation structure

[0066] 241 Lower foundation cavity

[0067] 25 Lower connector

[0068] 251 lower interface through hole

[0069] 3 Middle connection surface

[0070] 3' virtual middle connection surface

[0071] 3” intermediate connector

[0072] 31 middle hole

[0073] 4a-c First to third soft actuator components DETAILED DESCRIPTION

[0074] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0075] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0076] See also Figure 1-4 , Figure 1 FIG1 shows a schematic structural diagram of a parallel bending soft actuator of the present invention. Figure 2 Shown Figure 1 Schematic diagram of the half-section three-dimensional structure of the AA section, Figure 3 Shown Figure 1 In the AA section view, Figure 4 The right side view of a parallel bending soft actuator of the present invention is shown. The parallel bending soft actuator is symmetrically connected by two upper and lower soft actuator components (an upper soft actuator component 1 and a lower soft actuator component 2 respectively), and the upper soft actuator component 1 and the lower soft actuator component 2 share the same middle connecting surface 3, and the middle connecting surface 3 is respectively connected to the bottom surface of the upper soft actuator component 1 and the lower soft actuator component 2. The material of the parallel bending soft actuator can be made of elastic material or other suitable materials, for example, and can be set according to specific needs. In order to simplify the manufacturing process and improve the overall strength, the parallel bending soft actuator is, for example, manufactured by one-time integral forming. It is understandable that the parallel bending soft actuator can also not adopt the one-time integral forming process, but each component can be manufactured separately and then formed into a whole by pasting.

[0077] See also Figure 1-4In the present invention, the upper soft actuation component 1 includes an upper connection port 15, an upper base structure 14, an upper wavy non-rotating body structure and an upper fingertip structure 11 connected in sequence along a first direction (i.e., the X direction in the figure), and an upper cavity structure is formed between the upper connection port 15, the upper base structure 14, the upper wavy non-rotating body structure and the upper fingertip structure 11. The end of the upper fingertip structure 11 away from the upper wavy non-rotating body structure is closed, and the upper cavity structure includes the upper interface through hole 151, the upper base cavity 141, the upper non-rotating body cavity (the upper wave crest cavity 121 and the upper wave trough cavity 131 arranged alternately) and the upper fingertip cavity (not marked) connected in sequence, and the first direction is parallel to the axial direction of the upper soft actuation component 1. The lower soft actuator component 2 includes a lower connecting port 25, a lower base structure 24, a lower wavy non-rotating body structure and a lower fingertip structure 21 connected in sequence along a first direction (X direction in the figure), and a lower cavity structure is formed between the lower connecting port 25, the lower base structure 24, the lower wavy non-rotating body structure and the lower fingertip structure 21. The end of the lower fingertip structure 21 away from the lower wavy non-rotating body structure is closed, and the lower cavity structure includes the lower interface through hole 251, the lower base cavity 241, the lower non-rotating body cavity (the lower peak cavity 221 and the lower trough cavity 231 are alternately arranged) and the lower fingertip cavity (not marked) that are connected in sequence.

[0078] See also Figure 1-4 In the present invention, in the upper soft actuator assembly 1, the top surface of the upper wavy non-rotating structure is corrugated, and the bottom surface of the upper wavy non-rotating structure is flat or corrugated. The upper wavy non-rotating structure includes upper wave crest structures 12 and upper wave trough structures 13 alternately arranged along the first direction. The upper wave crest structures 12 and the upper wave trough structures 13 can be arranged at a certain draft angle. In the first direction, the width of the upper wave crest structures 12 decreases as it moves away from the bottom surface of the upper soft actuator assembly 1.

[0079] See also Figure 5 and Figure 6 ,like Figure 5 As shown, the peak contour line 12a is an arch with a straight line (slightly straight line) at the top, and the trough contour line 13a is an arch with an arc at the top; Figure 6 As shown, the peak contour line 12a is an arch with an arc at the top, and the trough contour line 13a is an arch with an arc at the top. Figure 5 and Figure 6), the distance between the contour line of the adjacent upper trough structure 13 (trough contour line 13a) and the contour line of the upper crest structure 12 (peak contour line 12a) tends to increase as it moves away from the bottom surface of the upper soft actuator component 1; depending on the specific shapes of the crest contour line 12a and the trough contour line 13a, this overall increasing trend can be, for example, gradually increasing, or first gradually increasing and then remaining unchanged, and of course it can also be other suitable changing trends.

[0080] See also Figure 1-4 In the present invention, in the lower soft actuator component 2, the top surface of the lower wavy non-rotating structure is corrugated, the bottom surface of the lower wavy non-rotating structure is flat or corrugated, and the lower wavy non-rotating structure includes a lower wave crest structure 22 and a lower wave valley structure 23 alternately arranged along the first direction, and the lower wave crest structure 22 and the lower wave valley structure 23 can be arranged to have a certain draft angle. Since the upper and lower soft actuator components are symmetrical structures, please refer to the relevant description of the upper wavy non-rotating structure for the structural features of the lower wavy non-rotating structure, which will not be elaborated here. Through this design, it can be ensured that the parallel bending soft actuator is easy to bend and deform in the upper and lower directions, and the bending deformation is coordinated and the stress distribution is uniform; at the same time, in the left and right directions ( Figure 1 With this design, the bending deformation is mainly caused by the change in the angle between the crests of adjacent crest structures, so that the side surfaces of the crest structure do not need to be expanded or squeezed to produce deformation.

[0081] like Figure 2 and 3As shown, in the present invention, the size (including radial size and height) of the upper fingertip structure 11 of the upper soft actuator can be the same as the peak size of the upper peak structure 12, or can be different from the size of the upper peak structure 12; as an example, the height h1 of the upper fingertip structure 11 (defined as the vertical distance from the top of the upper fingertip structure 11 to the symmetry plane) can be, for example, 1 / 2 times to 1 times the height h2 of the upper peak structure 12 (defined as the vertical distance from the top of the upper peak structure 12 to the symmetry plane), for example, 1 / 2 times, 2 / 3 times, 3 / 4 times or 1 times; the radial size of the upper fingertip structure 11 can be, for example, 1 / 2 times to 1 times the radial size of the upper peak structure 12, for example, 1 / 2 times, 2 / 3 times, 3 / 4 times or 1 times. The radial dimension and height h4 of the upper root structure 14 are the same as those of the upper crest structure 12. The cavity of the upper root structure 14 (upper root cavity 141) is trumpet-shaped. The thickness of the upper root structure 14 is thicker than other parts. The wall of the upper root structure 14 is thickened, which can enhance the stability of the upper soft actuator component 1 and the upper connection port 15. The height h3 of the upper connection port 15 (defined as the vertical distance from the top of the upper connection port 15 to the symmetry plane) is 1 / 3 to 1 times the height h4 of the upper root structure 14, for example, 1 / 3, 1 / 2, 2 / 3, 3 / 4 or 1 times; the area of ​​the cross section perpendicular to the X direction of the upper connection port 15 is 1 / 6 to 1 times the area of ​​the cross section perpendicular to the X direction of the upper root structure 14, for example, 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, 2 / 3 times, 3 / 4 times, or 1 times; the radial dimension of the cross section perpendicular to the X-direction of the upper connecting port 15 is 1 / 3 to 1 times, for example, 1 / 3, 1 / 2, 2 / 3, 3 / 4, or 1 times, of the radial dimension of the cross section perpendicular to the X-direction of the upper base structure 14; the minimum radial cross-sectional area of ​​the upper trough cavity 131 of the upper trough structure 13 is not less than 1 / 16 of the maximum radial cross-sectional area of ​​the upper peak cavity 131 of the upper peak structure 13. Since the upper and lower soft actuating assemblies are symmetrical structures, the structural features, sizes, and shape features of the lower soft actuating assembly 2 are the same as those of the upper soft actuating assembly 1, and are not further described here.

[0082] See also Figure 2 and Figure 3In the present invention, in the upper cavity structure of the upper soft actuating component 1 of the parallel bending soft actuator, the upper crest structure 12 or the upper trough structure 13 is not connected to the intermediate connecting surface 3 except for the two radial sides thereof, and the other parts of the upper crest structure 12 or the upper trough structure 13 are not connected to the intermediate connecting surface 3, and the minimum cross-sectional area of ​​the upper trough cavity 131 of the upper trough structure 13 in the radial direction is not less than 1 / 16 of the maximum cross-sectional area of ​​the upper crest cavity 121 of the upper crest structure 12 in the radial direction; similarly, the parallel bending In the lower cavity structure of the lower soft actuator component 2 of the soft actuator, the lower peak structure 22 or the lower trough structure 23 is not connected to the intermediate connecting surface 3 except for the two radial sides thereof, and other parts of the lower peak structure 22 or the lower trough structure 23 are not connected to the intermediate connecting surface 3, and the minimum cross-sectional area of ​​the lower trough cavity 231 of the lower trough structure 23 in the radial direction is not less than 1 / 16 of the maximum cross-sectional area of ​​the lower peak cavity 221 of the lower peak structure 12 in the radial direction; the advantage of such a structural design is that it is easy to demold and can be made using a mold.

[0083] See also Figure 2 and 3 In the present invention, the upper and lower surfaces of the intermediate connecting surface 3 are wavy structures, the upper surface of the intermediate connecting surface 3 is continuously connected to the bottom surface of the upper soft actuating component 1, and the lower surface of the intermediate connecting surface 3 is continuously connected to the bottom surface of the lower soft actuating component 2.

[0084] See also Figure 1-4 In the present invention, the upper connection port 15 and the lower connection port 25 of the connecting fluid are respectively connected to external equipment, and the working medium can flow into or out of the upper cavity structure (lower cavity structure) through the upper connection port 15 (lower connection port 25). The working medium can be, but is not limited to, gas, water, hydraulic oil and other fluids. The parallel bending soft actuator has an overall multi-degree-of-freedom bending deformation, and the upper interface / lower interface of the connecting fluid can be filled with fluid by a driving device, and the lower interface / upper interface of the connecting fluid can be extracted by a driving device. At this time, the distance between adjacent peak structures in the upper and lower soft actuator components changes, so that the parallel bending soft actuator is bent. It can be understood that the parallel bending soft actuator can be bent by filling or extracting fluid from any one of the upper interface and the lower interface separately.

[0085] See also Figure 1-4In the present invention, an intermediate through hole can be formed in the intermediate connecting surface 3 and penetrates the intermediate connecting surface 3 along its length direction, so that when connected in series with other soft brake modules, it can also serve as a place for placing communicating air pipes and other communication equipment; it can be understood that the intermediate through hole of the intermediate connecting surface 3 can also serve as a channel for accommodating fingers or limbs, so that the parallel bending soft actuator can be used as a rehabilitation device for fingers or limbs.

[0086] See also Figure 7 The present invention also provides a structural diagram of another parallel bending soft actuator, which is Figure 1-6 Compared with the parallel bending soft actuator shown in , the difference lies in the structure of the middle connecting surface 3 and the connection method between the middle connecting surface 3 and the bottom surface of the upper and lower soft actuating components. The other structures are the same and will not be described here. Specifically, the upper surface of the middle connecting surface 3 is a plane, and the upper surface of the middle connecting surface 3 is discontinuously connected to the bottom surface of the upper soft actuating component 1. It is connected at the bottom surface corresponding to the upper crest structure 12 of the upper soft actuating component 1, and is not connected at the bottom surface corresponding to the upper trough structure 13. The bottom surface corresponding to the upper trough structure 13 and the middle connecting surface 3 enclose a triangular hole; the lower surface of the middle connecting surface 3 is a plane, and the lower surface of the middle connecting surface 3 is discontinuously connected to the bottom surface of the lower soft actuating component 2. It is connected at the bottom surface corresponding to the lower crest structure 22 of the lower soft actuating component 2, and is not connected at the bottom surface corresponding to the lower trough structure 23.

[0087] See also Figure 8 The present invention also provides a schematic diagram of the structure of a third parallel bending soft actuator. Figure 1-6 Compared with the parallel bending soft actuator shown in , the difference is that there is no intermediate connection surface. In other words, it is equivalent to setting a virtual intermediate connection surface 3'. The bottom surfaces of the upper and lower soft actuator components are directly connected. The other structures are the same and will not be described here. Specifically, the upper and lower soft actuator components are connected at the bottom surfaces corresponding to their respective peak structures, and are not connected at the bottom surfaces corresponding to their respective trough structures, ultimately forming the following Figure 6 In the structure shown, a diamond-shaped hole is formed between the bottom surface corresponding to the upper trough structure 13 of the upper soft actuating component 1 and the bottom surface corresponding to the lower trough structure 23 of the lower soft actuating component 2 .

[0088] See also Figure 9The present invention also provides a structural schematic diagram of a fourth parallel bending soft actuator, which is composed of three soft actuator components 4a, 4b and 4c. The three soft actuator components 4a, 4b and 4c are evenly arranged around the circumference of an intermediate connector 3". The bottom surface of each soft actuator component 4a, 4b or 4c is connected to the side wall of the intermediate connector 3". The two adjacent soft actuator components (for example, soft actuator components 4a and 4b) are at an angle of 120°. The structure of each soft actuator component 4a, 4b or 4c is similar to the upper soft actuator component 1 (or lower soft actuator component 2) mentioned above, and will not be elaborated here. The parallel bending soft actuator can change its length as needed, or be used as a modular unit. The parallel bending soft actuator can be formed as a whole, or each component can be made separately and then assembled.

[0089] See also Figure 9 When the parallel bending soft actuator is in use, for example, the cavity structure of each soft actuator component 4a, 4b or 4c can be inflated and inhaled separately to achieve movement in three directions; for example, two-by-two can be inflated and inhaled (that is, the cavity structures of two soft actuator components are inflated or inhaled at the same time, or one is inflated and the other is inhaled) to achieve movement in different directions; for example, three can be inflated, inhaled at the same time, or mixed inflation and inhalation (partial inflation, the rest is inhaled), and according to the different inflation or inhalation air pressures, movement in any direction in space (bending or twisting movement) can be made. It should be noted that if inflated or inhaled at the same time, the air pressure in the cavity structure of each soft actuator component 4a, 4b or 4c cannot be the same at the same time.

[0090] Figure 9 The parallel bending soft actuator structural design shown has the following beneficial effects: it can realize arbitrary movement in all directions in a small space with multiple degrees of freedom; the bending angle is related to the pressure in the internal cavity structure, and the higher the air pressure, the greater the bending angle; it exhibits good flexibility under zero or low air pressure, and the higher the air pressure, the greater the stiffness and output force of the parallel bending soft actuator; during the bending process, the air pressure of the parallel bending soft actuator cavity structure can be adjusted according to the requirements of stiffness and force. Figure 9 The parallel bending soft actuator structure shown achieves flexible movement of a three-dimensional soft arm in space through a combination of multiple modules. It can move in a small space, which is helpful for search and rescue work in the small space caused by earthquakes. It can be used for laparoscopic surgery and can be used as a claw that can grasp conchs, shells and other aquatic products underwater.

[0091] like Figure 9As shown, an intermediate hole 31 may be provided in the middle portion 3" of the intermediate connector. The intermediate hole 31 may not only reduce the rigidity of the intermediate connector and increase the deformation of the parallel bending soft actuator, but also serve as a connecting pipe or ventilation pipe when two parallel bending soft actuators are connected in series.

[0092] In summary, a parallel bending soft actuator of the present invention includes a pair of soft actuator components, namely an upper soft actuator component and a lower soft actuator component. The bottom surfaces of the two parts of the soft actuator components are directly symmetrically connected or symmetrically connected through an intermediate connecting surface. When a load is applied to the parallel bending soft actuator of the present invention, the stress distribution inside the structure is uniform, the stress concentration is small, and the service life is long; and this structure adopts a parallel symmetrical structure, has deformation coordination, and can produce larger deformation under smaller loads. The parallel bending soft actuator of the present invention, which includes a pair of symmetrically arranged soft actuator components, is made of elastic material. When used as the finger part of a hand rehabilitation device, the hand can be bent and stretched to different degrees by adjusting the pressure of the fluid. At the same time, it can generate a large pulling force when performing hyperextension rehabilitation on the finger. It will not impose rigid constraints and pressure on the blood vessels and muscles of the hand, and will not cause discomfort when used for a long time. Another parallel bending soft actuator of the present invention includes an intermediate connector and three or more soft actuator components uniformly arranged around the circumference of the intermediate connector. By combining multiple modules, the flexible movement of the three-dimensional soft arm in space is achieved, and it can move in a small space. It is helpful for search and rescue work in the small spaces caused by earthquakes, can be used for laparoscopic surgery, and can be used as a claw capable of grabbing conchs, shells and other aquatic products underwater. This structure can, for example, reduce the rigidity of the intermediate connector by providing an intermediate hole in the intermediate connector to increase the deformation of the parallel bending soft actuator. The parallel bending soft actuator of the present invention has a simple manufacturing process, does not require gluing, and can be formed as a whole in one go. The parallel bending soft actuator of the present invention increases the bottom width of the trough structure in the radial direction while ensuring the same bending deformation, and on the side of the soft actuator component, the distance between the contour line of the adjacent trough structure and the contour line of the crest structure tends to increase as it moves away from the bottom surface of the soft actuator component as a whole, thereby increasing the overall cross-sectional area of ​​the trough structure. This not only improves the overall strength and rigidity of the parallel bending soft actuator, but also improves the lateral bending resistance of the soft actuator component. At the same time, this design can also improve the feasibility of demolding and enable the integral molding of the mold. The crest structure of the parallel bending soft actuator of the present invention has an increasingly larger axial width near the bottom surface, which improves the overall strength and rigidity of the parallel bending soft actuator under the same bending deformation capacity, especially the lateral bending resistance of the soft actuator component. The crest structure of the parallel bending soft actuator of the present invention has a larger deformation, while the bottom deformation of its trough structure is smaller, which complies with the principle of deformation coordination when inflating and deflating. The parallel bending soft actuator of the present invention utilizes a completely hollow structure. This allows for easy mold release and can also be fabricated using methods such as 3D printing. The overall structure of the parallel bending soft actuator has an optimal height-to-width ratio, enabling it to provide a strong gripping force when used as a gripper.The parallel bending soft actuator of the present invention can generate a large force whether bending or stretching, and can bear a large load. The air pressure-deformation relationship of the parallel bending soft actuator of the present invention is appropriate during the bending deformation process, and the unnecessary expansion is reduced during the deformation process. The parallel bending soft actuator of the present invention adopts an integral molding structure, and when used as the finger part of a hand rehabilitation device, there is no need to distinguish the length and position of the knuckle joints of different people. The deformation of the parallel bending soft actuator of the present invention is mainly caused by the change in the angle between adjacent wave peaks, rather than by the expansion and extrusion deformation of the sides on both sides of the wave peaks. The parallel bending soft actuator of the present invention can also be used as a bionic claw to realize actions such as grasping, holding and pulling outward. The grasping force can be changed according to the weight of the target object without causing damage to the grasped object. The parallel bending soft actuator of the present invention can also be used as an actuator, as a driving unit. The parallel bending soft actuator of the present invention has a simple and compact structure, is easy to manufacture, and has broad market prospects.

[0093] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

[0094] In the description herein, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of the embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, assemblies, methods, components, materials, parts, etc. In other cases, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of the embodiments of the present invention.

[0095] Reference throughout this specification to "one embodiment," "an embodiment," or "a specific embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the invention described and illustrated herein are possible in light of the teachings herein and are considered part of the spirit and scope of the invention.

[0096] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0097] In addition, unless otherwise expressly indicated, any marking arrows in the drawings should be regarded as illustrative only and not limiting. Furthermore, unless otherwise indicated, the term "or" as used herein is generally intended to mean "and / or." Where a term is unclear in providing separation or combination capabilities, the combination of components or steps will also be considered as indicated.

[0098] As used in the description herein and throughout the claims that follow, “a,” “an,” and “the” include plural references unless otherwise indicated. Likewise, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless otherwise indicated.

[0099] The above description of the illustrated embodiments of the present invention (including that described in the Abstract) is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, as those skilled in the art will recognize and appreciate, various equivalent modifications are possible within the spirit and scope of the present invention. As noted, modifications may be made to the present invention in light of the above description of the illustrated embodiments of the present invention, and such modifications will be within the spirit and scope of the present invention.

[0100] Systems and methods have been generally described herein in detail to facilitate understanding of the present invention. In addition, various specific details have been given to provide an overall understanding of embodiments of the present invention. However, those skilled in the relevant art will recognize that embodiments of the present invention may be practiced without one or more of these specific details, or with other devices, systems, accessories, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0101] Thus, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are intended within the foregoing disclosure, and it should be understood that in some cases, some features of the invention will be employed without the corresponding use of other features without departing from the scope and spirit of the claimed invention. Thus, many modifications may be made to adapt a particular environment or material to the true scope and spirit of the invention. The invention is not intended to be limited to the specific terminology used in the claims below and / or to the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the invention is intended to include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention will be determined solely by the appended claims.

Claims

1. A parallel bending soft actuator, characterized in that: include: At least two soft actuation components, the bottom surface of one soft actuation component being connected to the bottom surface of another soft actuation component; The soft actuation assembly includes a connection port, a base structure, and a wavy non-rotating structure sequentially connected along a first direction, a cavity structure is formed between the connection port, the base structure, and the wavy non-rotating structure, and the first direction is parallel to the axial direction of the soft actuation assembly; The wavy non-rotating structure includes crest structures and trough structures alternately arranged along the first direction, and the circumferential width of the crest structures gradually decreases from the bottom surface of the soft actuating component to the top surface away from the bottom surface of the soft actuating component; The cavity of the base structure is trumpet-shaped, and the wall thickness of the base structure is greater than the wall thickness of other parts of the soft actuator component; In a cross section of the soft actuating component, the distance between the contour lines of the adjacent trough structures and the contour lines of the crest structures tends to increase as a whole, from the bottom surface of the soft actuating component toward the top surface away from the bottom surface of the soft actuating component. The contour lines of the crest structures are arched with a straight line or arc at the top, while the contour lines of the trough structures are arched with an arc at the top. The bottom surface of the wavy non-rotating structure is corrugated, and includes alternately connected planes and concave arc surfaces, the planes are correspondingly connected to the crest structures, and the concave arc surfaces are correspondingly connected to the trough structures.

2. The parallel bending soft actuator according to claim 1, characterized in that: The parallel bending soft actuator includes a pair of symmetrically arranged soft actuator components, and the bottom surface of one soft actuator component is arranged opposite to the bottom surface of the other soft actuator component.

3. The parallel bending soft actuator according to claim 2, characterized in that: The parallel bending soft actuator further includes an intermediate connecting surface, through which the bottom surface of one soft actuating component is connected to the bottom surface of another soft actuating component.

4. The parallel bending soft actuator according to claim 3, characterized in that: The intermediate connecting surface includes a corrugated surface or a flat surface.

5. The parallel bending soft actuator according to claim 1, characterized in that: The material of the parallel bending soft actuator includes elastic material.

6. The parallel bending soft actuator according to claim 1, characterized in that: The parallel bending soft actuator is integrally formed.

7. The parallel bending soft actuator according to claim 1, characterized in that: The soft actuation component further comprises a fingertip structure, wherein the fingertip structure is connected to an end of the wave-shaped non-rotating structure away from the base structure.

8. The parallel bending soft actuator according to claim 1, characterized in that: The parallel bending soft actuator includes an intermediate connector and three soft actuating components uniformly arranged around the circumference of the intermediate connector, and the bottom surface of each soft actuating component is connected to the side wall of the intermediate connector.

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