A soft drive and soft robot thereof

Abstract

The present invention discloses a soft actuator comprising an actuation layer and a pressure chamber. The actuation layer comprises a wrapping layer made of a deformable material, the interior of the wrapping layer forming a cavity-shaped structure, and the cavity containing an insulating liquid medium. The wrapping layer is a flat structure, with at least one pair of flexible electrodes bonded to two opposing flat surfaces of the wrapping layer. The pressure chamber is a cavity-shaped structure having at least one opening. The actuation layer is bonded to the opening of the pressure chamber, forming a sealed cavity with the pressure chamber, wherein a gas at a preset pressure is contained within the sealed cavity. The soft actuator disclosed by the present invention has a simple structure, is easy to prepare, and the selected materials are readily available. The manufactured soft actuator can be made into any desired shape, has strong adaptability, and has a fast response speed.

Description

Technical Field

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

[0002] With the development of science and technology, flexible drives are increasingly used in bionic robots, soft grippers, and medical rehabilitation. Existing rigid drives are heavy and bulky, with regular and single shapes, complex drive structures and control methods, and poor compatibility with soft robots. There are many problems in practical applications.

[0003] Most current soft actuators are made of soft materials such as shape memory alloys, dielectric elastomers, and hydrogels, and are driven by electricity, gas, temperature, and chemistry. However, gas drive requires rigid gas source equipment and complex valves for inflation and deflation, temperature drive requires both heating and cooling devices, and chemical drive is limited by chemical reactions, has limited speed, and cannot be carried out for a long time.

[0004] Therefore, how to solve the problems of slow driver response time, single driving mode and complex structure in the prior art has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In order to solve one of the above technical problems, the present invention discloses a soft driver with a simple structure, easy preparation, and easy-to-obtain selected materials. The manufactured soft driver can be made into any required shape, has strong adaptability, and fast response speed.

[0006] The software driver disclosed in the present invention is realized by the following technical solutions:

[0007] A soft driver comprises an actuation layer and a pressure chamber; the actuation layer comprises a wrapping layer made of a deformable material, the interior of the wrapping layer being a cavity-shaped structure, and the cavity containing an insulating liquid medium; the wrapping layer is a flat structure, and at least one pair of flexible electrodes is bonded to two opposing flat surfaces of the wrapping layer; the pressure chamber is a cavity-shaped structure having at least one opening; the actuation layer is bonded to the opening of the pressure chamber, forming a sealed cavity with the pressure chamber, and the sealed cavity is provided with gas at a preset pressure.

[0008] On the basis of the above technical solution, the present invention can also be further improved as follows.

[0009] Furthermore, the wrapping layer is made of silicone material, and the liquid medium is vegetable oil or transformer oil.

[0010] Furthermore, the pressure chamber has a plurality of openings, the plurality of openings are opened in preset directions, and one of the actuating layers is bonded to each of the openings.

[0011] Furthermore, there are multiple pressure chambers, each of which has an opening, and multiple soft drivers are connected end to end to form a soft driver group.

[0012] Furthermore, the pressure chamber includes two oppositely arranged supporting side walls, and multiple insulating layers are arranged at circumferential intervals between the two supporting side walls. The multiple insulating layers and the two supporting side walls form a cavity-shaped structure with multiple openings, and the actuating layer is bonded to the multiple openings to seal the cavity-shaped structure.

[0013] Furthermore, the supporting sidewall is made of a soft material having a harderness greater than that of the actuating layer.

[0014] Furthermore, the number of the plurality of open structures is 5 to 10, and they are evenly spaced and distributed along the circumference of the pressure chamber.

[0015] Furthermore, the software driver further includes a control module, which is in control connection with the actuation layer.

[0016] Furthermore, the control module includes a capacitance detection device, which is connected to the actuation layer circuit and is used to detect the distance between the flexible electrode pairs on the actuation layer in real time and provide real-time feedback to the control module. The entire control loop is closed-loop control.

[0017] The soft actuator provided by this invention is primarily a closed-loop soft actuator based on electrical control under fixed air pressure. This overcomes the problems of existing actuators, such as heavy weight and bulk, regular and monotonous shapes, complex drive structures and control methods, and poor integration with soft robots. The basic scheme uses the Maxwell force between flexible electrodes to compress the actuation layer, generating strain and achieving output displacement under fixed air pressure.

[0018] The present invention also discloses a soft robot, including a soft driver of any of the above-mentioned methods. Due to the beneficial technical effects of the above-mentioned soft driver, the soft robot also has corresponding beneficial technical effects, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of a specific embodiment of the actuation layer of the present invention;

[0020] Figure 2 A schematic diagram of the structure of a software driver provided by the present invention before and after power-on;

[0021] Figure 3 A schematic structural diagram of another specific implementation of a software driver provided by the present invention;

[0022] Figure 4 A schematic structural diagram of another specific implementation of a software driver provided by the present invention;

[0023] Figure 5 A schematic structural diagram of another specific implementation of a software driver provided by the present invention;

[0024] Figure 6 for Figure 5 A schematic diagram illustrating the working principle of a specific embodiment of the software driver shown;

[0025] Figure 7 This is a schematic diagram of the control principle of the software driver provided by the present invention.

[0026] The part numbers in the figure are represented as follows:

[0027] 1. Actuation layer, 4. Pressure chamber, 5. Soft actuator group, 11. Wrapping layer, 12. Fluid medium, 13. Flexible electrode pair, 7. Insulation layer, 8. Support side wall. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. The principles and features of the present invention will be described below in conjunction with the accompanying drawings. It should be noted that the embodiments and features of the embodiments in this application may be combined with each other unless there is a conflict. The examples provided are intended only to illustrate the present invention and are not intended to limit the scope of the invention.

[0029] like Figures 1 to 7 , Figure 1 Schematic diagram of the structure of a specific embodiment of the actuation layer of the present invention; Figure 2 A schematic diagram of the structure of a software driver provided by the present invention before and after power-on; Figure 3 A schematic structural diagram of another specific implementation of a software driver provided by the present invention; Figure 4 A schematic structural diagram of another specific implementation of a software driver provided by the present invention; Figure 5 A schematic structural diagram of another specific implementation of a software driver provided by the present invention; Figure 6 for Figure 5 A schematic diagram illustrating the working principle of a specific embodiment of the software driver shown; Figure 7 This is a schematic diagram of the control principle of the software driver provided by the present invention.

[0030] In the embodiment 1, in a specific implementation of a software driver disclosed in the present invention, as Figure 1 、 Figure 2 As shown, the soft actuator comprises an actuation layer 1 and a pressure chamber 4. The actuation layer 1 comprises a wrapping layer 11 made of a deformable material, such as silicone. The interior of the wrapping layer 11 is a cavity-shaped structure filled with an insulating liquid medium. The wrapping layer 11 is a flat structure, with at least one pair of flexible electrodes 13 bonded to its two opposing flat surfaces. The pressure chamber 4 is a cavity-shaped structure with an opening. The actuation layer 1 is bonded to the opening of the pressure chamber 4, forming a sealed cavity with the pressure chamber 4. Gas at a preset pressure is contained within the sealed cavity.

[0031] The flexible electrode pair 13 may be made by applying carbon paste on silicone, or by ion spraying on silicone, or by mixing carbon nanotubes and silicone.

[0032] The actuating layer 1 is a layered film (such as Figure 1 (As shown, however, the diagram is merely an enlarged schematic and may differ from the actual structure.) The structure is essentially a multi-layered, fully deformable structure. The middle layer is filled with a fluid medium 12, which can be an insulating liquid such as insulating, high-voltage-resistant vegetable oil or high-voltage transformer oil. This makes the entire actuation layer 1 resistant to breakdown and capable of recovering function after breakdown. Flexible electrode pairs 13 are coated on both sides. When voltage is applied, the Maxwell force compresses the actuation layer 1, generating strain.

[0033] The pressure chamber 4 described above can be a hollow cavity made of a soft material, or a cavity-shaped structure with a certain degree of rigidity, such as plastic or resin, with a single opening for sealingly bonding with the actuation layer 1 to form a sealed cavity. The pressure chamber 4 can be cylindrical in shape or can be designed as a special shape as needed.

[0034] In this specific embodiment, the soft driver can achieve unidirectional linear actuation by applying voltage to the flexible electrode pair 13 on both sides of the actuation layer 1. The two layers of flexible electrodes attract each other due to the Maxwell force, thereby squeezing the wrapping layer 11, causing the actuation layer 1 to produce strain and increase its area. Since a certain pressure of gas is preset in the closed cavity, after the voltage is applied, the actuation layer 1 will bulge a certain height on the original basis, thereby achieving the purpose of unidirectional linear actuation.

[0035] In the second embodiment, the pressure chamber 4 is made into a cavity open to a specific direction, and the actuation layer 1 is sealed and bonded to the pressure chamber 4 in a specific direction to form a sealed structure with a certain pressure inside. By applying voltage to the actuation layer 1 in a specific direction, the actuation layer 1 is raised in that direction to achieve actuation. At the same time, by applying voltages of different magnitudes to the actuation layer 1 in multiple directions, the driver can generate actuation displacements of different magnitudes in different directions at the same time. Drivers can also be superimposed in multiple directions to increase the actuation displacements in multiple directions. By selectively applying voltages to different numbers of drivers in different directions, actuation displacements of different magnitudes in different directions can be achieved. Figure 4 In the illustrated embodiment of the actuator, there are two oppositely opened pressure chambers 4 , to which two opposite actuating layers 1 are bonded respectively.

[0036] Example 3, as Figure 3 As shown, based on the first embodiment, the soft driver of the first embodiment is used as a driving unit, and multiple such driving units are connected end to end. The connection method can be bonding or other forms. For example, the actuating layer 1 of one driver can be bonded to the bottom of the pressure chamber 4 of another driver to form a soft driver group 5. The actuating layer 1 of each soft driver unit is controlled by applying voltage separately. When multiple brake units all generate brakes, linear actuation with a larger displacement can be achieved. If each driving unit is controlled according to certain rules in different control methods, movements similar to caterpillar walking can also be achieved.

[0037] Example 4, as Figure 5 、 Figure 6As shown, the pressure chamber 4 comprises two opposing supporting sidewalls 8, with six insulating layers 7 spaced circumferentially between the two supporting sidewalls 8. These six insulating layers 7 and the two supporting sidewalls 8 form a cavity-shaped structure with six openings. The actuation layer 1 is bonded to each of the six openings, sealing the cavity-shaped structure and forming a hexagonal prism-like structure. The six insulating layers 7 not only provide insulation but also support. The supporting sidewalls 8 are made of a soft material with a harder hardness than the actuation layer. A preferred embodiment is that the insulating layer 7 and the supporting side wall 8 are both made of silicone with a hardness greater than that of the actuating layer 1. In this way, since the silicone itself is also flexible, when it is not inflated, the entire device can be compressed to a very small size, which is convenient for the installation and use of the soft robot. After inflation (the air pressure does not need to be too high, just slightly higher than the external air pressure), a certain air pressure is formed inside, which can inflate the driver. Since the insulating layer 7 and the supporting side wall 8 are made of silicone material, its hardness is greater than that of the actuating layer 1, so at the same air pressure, the actuating layer 1 will produce a larger deformation, and when the actuating layer 1 is alternately applied with voltage, the deformation of the insulating layer 7 and the supporting side wall 8 is very small, and its hardness is sufficient to play a supporting role, truly realizing the effect of soft drive, which is more suitable for soft robots.

[0038] Specifically, the number of the open structures is preferably 5 to 10, and they are evenly spaced along the circumference of the pressure chamber 4, so that better control can be achieved.

[0039] Specifically, such as Figure 5 As shown, six actuation layers 1 are bonded to each other to form a ring-shaped actuation layer 1. Adjacent actuation layers 1 are bonded with an insulating layer 7, and both sides are sealed and bonded by supporting side walls 8 to form a sealed cavity with a certain pressure inside. Figure 6 The individual actuation layer 1 units 1a, 1b, 1c, 1d, 1f, and 1e shown are insulated from each other and can be controlled individually. When voltage is applied to a single actuation layer 1 unit 9 in contact with the ground, the actuation layer 1 unit 1a bulges, causing the center of gravity of the rolling drive to shift forward and roll a certain angle. Voltage is applied to multiple actuation layer 1 units in sequence, thereby realizing rolling actuation of the brake.

[0040] In the various embodiments described above, the soft driver includes a control module, which is in control connection with each actuation layer 1 and can control each actuation layer 1 individually.

[0041] Most existing drivers operate in an open-loop output mode, meaning they only control the driver's operation and are unable to determine the magnitude of the driver's output displacement and make real-time adjustments. To address this issue, the present invention provides a closed-loop control solution for the driver. This allows for sensing the output displacement, determining its magnitude, and making real-time adjustments, thereby increasing output accuracy.

[0042] Specifically, the control module further includes a capacitance detection device, which is connected to the circuit of the actuation layer 1 and is used to detect the distance between the flexible electrode pairs 13 on the actuation layer 1 in real time and provide real-time feedback to the control module. The entire control circuit is a closed-loop control. It will be appreciated that when there are multiple actuation layers 1, the control module is connected to each actuation layer 1 to achieve independent closed-loop control for each actuation layer 1.

[0043] The method for achieving closed-loop control actuation is as follows: the actuation layer 1 and the flexible electrodes on both sides form a capacitor structure. When voltage is applied to the electrodes on both sides of the actuation layer 1, the actuation layer 1 generates strain, and the distance between the flexible electrode pairs 13 changes. At the same time as the driver outputs displacement, the capacitance of the capacitor changes accordingly. Based on the capacitance change, the displacement output is obtained in real time using a capacitance detection device.

[0044] Control principle such as Figure 7 As shown, when the output displacement is given, the external high-voltage discharge device applies the corresponding voltage, the driver actuation layer 1 is strained, the capacitance changes, and the output displacement is output. The capacitance detection device in the external circuit can measure the capacitance in real time, and the measured capacitance is converted into displacement and compared with the original value to achieve closed-loop precise control of the output displacement.

[0045] In combination with the above technical solutions, the software driver disclosed in the present invention has the following beneficial effects:

[0046] (1) The soft actuator disclosed in the present invention uses voltage to control the strain of the actuation layer to generate actuation, and has a fast response speed; at the same time, the structure is soft and simple, and is easy to arrange and process.

[0047] (2) The soft driver disclosed in the present invention can be made into various required shapes, can adapt to driving in various environments, and has better applicability.

[0048] (3) The actuating layer of the soft actuator disclosed in the present invention is composed of a simple deformation layer and a liquid cavity layer. It does not require rigid material fixation and does not require pre-stretching in advance, and has a simple structure.

[0049] (4) The soft actuator actuation layer structure disclosed in the present invention is a multi-layer structure in which an insulating liquid is filled inside the deformation layer. It can play the functional characteristics of other dielectric elastomer materials, and is relatively resistant to breakdown, can recover after breakdown, and can be reused.

[0050] (5) When voltage is applied to the actuating layer of the soft driver disclosed in the present invention, a variable capacitor is formed. By detecting the capacitance of the actuating layer, the size of the drive output displacement can be known, and thus adjustment can be made to form a closed-loop drive.

[0051] (6) The soft actuator disclosed in the present invention is composed only of a sealed cavity with an actuation layer and a corresponding power supply and control circuit, with a simple structure and various actuation modes.

[0052] The present invention further provides a soft robot comprising any of the soft actuators described above. Regarding specific application and connection methods, the soft actuator provided by the present invention can have a variety of application and connection methods, in combination with existing technologies, which will not be described in detail here.

[0053] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0054] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0055] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0056] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0057] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A soft driver for a soft robot, characterized in that: It includes an actuation layer, a pressure chamber, a high-voltage discharge device, and a control module; The actuation layer includes a wrapping layer made of a deformable material, the interior of the wrapping layer is a cavity-shaped structure, and the cavity is filled with an insulating liquid medium; the wrapping layer is a flat structure, and at least one pair of flexible electrodes is bonded to two opposite flat surfaces of the wrapping layer; The pressure chamber is a cavity-shaped structure having at least one opening; The actuating layer is bonded to the opening of the pressure chamber to form a sealed cavity with the pressure chamber, and a gas at a preset pressure is provided in the sealed cavity; By applying voltage to the flexible electrode pair on both sides of the actuation layer, the two layers of flexible electrodes attract each other due to Maxwell force, thereby squeezing the wrapping layer, causing the actuation layer to generate strain, and achieving output displacement under a fixed air pressure; The high-voltage discharge device is used to apply voltage to the flexible electrode pair; The control module includes a capacitance detection device, which is connected to the actuation layer circuit and is used to detect the distance between the flexible electrode pairs on the actuation layer in real time and provide real-time feedback to the control module. The entire control loop is closed-loop control.

2. A soft driver for a soft robot according to claim 1, characterized in that: The wrapping layer is made of silica gel, and the liquid medium is vegetable oil or transformer oil.

3. The soft driver for a soft robot according to claim 1, characterized in that: The pressure chamber has a plurality of openings, which are opened in preset directions, and each of the openings is bonded with an actuating layer.

4. The soft driver for a soft robot according to claim 1, characterized in that: There are multiple pressure chambers, each of which has an opening, and multiple soft drivers are connected end to end to form a soft driver group.

5. The soft driver for a soft robot according to claim 3, characterized in that: The pressure chamber includes two oppositely arranged supporting side walls, and multiple insulating layers are arranged at circumferential intervals between the two supporting side walls. The multiple insulating layers and the two supporting side walls form a cavity-shaped structure with multiple openings. The actuating layer is bonded to the multiple openings to seal the cavity-shaped structure.

6. The soft driver for a soft robot according to claim 5, characterized in that: The supporting sidewall is made of a soft material having a harderness than that of the actuating layer.

7. The soft driver for a soft robot according to claim 6, characterized in that: The number of the open structures is 5 to 10, and they are evenly spaced along the circumference of the pressure chamber.

8. A soft robot, characterized in that: The invention comprises a soft driver for a soft robot according to any one of claims 1 to 7.

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