Flexible radial drive based on dielectric elastomers and flexible radial drive system

Abstract

The application discloses a flexible radial driver based on a dielectric elastomer, which comprises a shell, a dielectric elastic layer made of a dielectric elastomer material arranged in the shell, a first electrode and a second electrode connected on both sides of the dielectric elastic layer, a containing cavity formed in the middle of the dielectric elastic layer and penetrating through the upper and lower surfaces of the dielectric elastic layer, and the shell is bound to the dielectric elastic layer from the outside. The driver has good flexibility, high response speed and low energy consumption while ensuring precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flexible devices, in particular to a flexible radial driver based on dielectric elastomer and a flexible radial driving system. BACKGROUND

[0002] With the development of bionic technology, people pay more and more attention to fine mechanical equipment such as robots, and the performance of the driver, such as compliance, response speed, precision, etc., is very demanding in fine mechanical equipment.

[0003] The current driver mainly includes mechanical driving, thermal energy driving, fluid driving (hydraulic pressure, pneumatic pressure), electromagnetic driving, etc., which all have the disadvantages of high energy consumption, poor compliance, complex structure, large volume, heavy weight, slow response speed and high noise. The existing driving technology is limited in many fields of application. SUMMARY

[0004] Therefore, the present application provides a flexible radial driver based on dielectric elastomer and a flexible radial driving system, which can ensure precision while having good compliance, high response speed and low energy consumption.

[0005] The present application provides a flexible radial driver based on dielectric elastomer, which comprises a dielectric elastomer layer made of dielectric elastomer material, a shell, a first electrode and a second electrode, a receiving cavity is formed in the middle of the dielectric elastomer layer through the upper and lower surfaces of the dielectric elastomer layer, the dielectric elastomer layer is arranged in the shell, the upper and lower end walls and the inner side wall of the shell constrain the dielectric elastomer layer, and the first electrode and the second electrode are arranged on both sides of the dielectric elastomer layer.

[0006] Further, the dielectric elastomer layer is a plurality of layers, the first electrode and the second electrode are a plurality of layers, the first electrode and the second electrode are alternately arranged on the upper and lower surfaces of the dielectric elastomer layer, and two adjacent dielectric elastomer layers share one first electrode or one second electrode.

[0007] Further, the dielectric elastomer layer is a plurality of layers, the first electrode and the second electrode are a plurality of layers, the first electrode and the second electrode are alternately arranged on the upper and lower surfaces of the dielectric elastomer layer, and two adjacent dielectric elastomer layers share one first electrode or one second electrode.

[0008] Further, the flexible radial driver based on the dielectric elastomer further comprises a first conductor and a second conductor, both of which are arranged in the shell, the first conductor is connected with the first electrodes and leads the first electrodes out of the shell, and the second conductor is connected with the second electrodes and leads the second electrodes out of the shell.

[0009] Further, the shell comprises an upper end cover, a lower end cover and a mounting cylinder, the dielectric elastomer layer is arranged in the mounting cylinder, the upper end cover and the lower end cover are arranged at both ends of the mounting cylinder, and through holes are formed in the upper end cover and the lower end cover at positions corresponding to the accommodating cavity, the first conductor and the second conductor are arranged between the outer sidewall of the dielectric elastomer layer and the inner sidewall of the mounting cylinder.

[0010] The driver further comprises a first connecting terminal and a second connecting terminal, both of which are arranged on the upper end cover or the lower end cover, the first conductor connects the first electrodes with the first connecting terminal, and the second conductor connects the second electrodes with the second connecting terminal.

[0011] Further, a first gasket is arranged between the upper end cover and the uppermost dielectric elastomer layer, and a second gasket is arranged between the lower end cover and the lowermost dielectric elastomer layer.

[0012] Further, both the first gasket and the second gasket are fixed on the dielectric elastomer layer and cover the first electrodes and the second electrodes, and a lubricating layer is formed between the first gasket and the upper end cover and between the second gasket and the lower end cover.

[0013] Further, both the first conductor and the second conductor are arranged between the sidewall of the dielectric elastomer layer and the shell, both of which are in the shape of a semi-cylinder, and an insulator is filled between the first conductor and the second conductor, the first conductor, the second conductor and the insulator together form a complete cylinder and cover the outer sidewall of the dielectric elastomer layer.

[0014] Further, both the first electrodes and the second electrodes are in the shape of a circular ring, and a first radius circumferential segment and a second radius circumferential segment are formed on the outer circumference of the circular ring, the radius of the first radius circumferential segment is greater than that of the second radius circumferential segment, the first radius circumferential segment of the first electrode is connected with the first conductor, and the first radius circumferential segment of the second electrode is connected with the second conductor.

[0015] The application further provides a flexible radial driving system, which comprises a rod, a power supply, a control unit and the flexible radial driver.

[0016] In summary, the application sets the dielectric elastic layer, and sets the first electrode and the second electrode on the upper and lower sides of the dielectric elastic layer, uses the inverse piezoelectric effect of the dielectric elastic layer to exert the force on the object placed in the accommodating cavity, so that the response speed of the driver is faster; since the dielectric elastic layer itself is flexible, and the force is related to the deformation amount of itself, so the precise control of the exerted force can be realized by the control of the applied voltage.

[0017] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, and can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following preferred embodiments are described in detail, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The axial structure schematic diagram of the flexible radial driver based on the dielectric elastomer provided by the embodiment of the application is shown.

[0019] Figure 2 The side structure schematic diagram of the flexible radial driver based on the dielectric elastomer is shown. Figure 1

[0020] Figure 3 The cross-sectional structure schematic diagram of the A-A direction is shown. Figure 2

[0021] Figure 4 The cross-sectional structure schematic diagram of the B-B direction is shown. Figure 2

[0022] Figure 5 The structure schematic diagram of the first conductor is shown. Figure 3

[0023] Figure 6 The structure schematic diagram of the first electrode is shown. Figure 3 DETAILED DESCRIPTION

[0024] In order to further illustrate the technical means and effects taken by the application to achieve the predetermined purposes, the following will be described in detail in combination with the drawings and the preferred embodiments.

[0025] ​​​​​This invention provides a flexible radial actuator and a flexible radial drive system based on a dielectric elastomer. The actuator can ensure precision while also having good compliance, high response speed and low energy consumption.

[0026] Figure 1 The figure shown is an isometric structural diagram of a flexible radial actuator based on a dielectric elastomer provided in an embodiment of the present invention. Figure 2 As shown Figure 1 A side view schematic diagram of a flexible radial actuator based on a dielectric elastomer. Figure 3 As shown Figure 2 A schematic diagram of the cross-sectional structure along the AA direction. (See diagram below.) Figures 1 to 3 As shown, the flexible radial actuator based on dielectric elastomer provided in this embodiment of the invention includes a dielectric elastic layer 10, a housing 20, a first electrode 31, and a second electrode 32 made of dielectric elastomer (DE) material. A receiving cavity 11 penetrating the upper and lower surfaces is formed in the middle of the dielectric elastic layer 10. The dielectric elastic layer 10 is disposed in the housing 20. The inner walls of the upper and lower ends and the inner sidewalls of the housing 20 bind the dielectric elastic layer 10. The first electrode 31 and the second electrode 32 are respectively disposed on both sides of the dielectric elastic layer 10.

[0027] In this embodiment, since the dielectric elastomer is a typical electroactive polymer (EAP), it has a certain degree of flexibility. When a voltage is applied in the thickness direction of the dielectric elastomer, the charge on the upper and lower electrodes accumulates to generate a high-intensity electric field. The intensity of the electric field is equal to the applied voltage divided by the thickness of the dielectric elastomer. The electric field generates an electric force effect equivalent to applying a positive pressure in the thickness direction of the dielectric elastomer. When the electric force is large enough, the dielectric elastomer will produce significant changes in area and thickness. Therefore, when a voltage is applied to both ends of the dielectric elastic layer 10 made of dielectric elastomer material through the first electrode 31 and the second electrode 32, respectively, the thickness of the dielectric elastic layer 10 will decrease. Correspondingly, its area in the plane perpendicular to the thickness direction will increase. However, the upper and lower ends and the sidewalls of the outer surface of the dielectric elastic layer 10 are restricted by the shell 20, and the dielectric elastic layer 10 can only extend towards its middle part, that is, in the direction of the accommodating cavity 11. At this time, the dielectric elastic layer 10 will apply a force to the object placed in the receiving cavity 11, such as a rotating shaft or connecting rod. Preferably, the actuator can grasp the object placed in the receiving cavity 11 in its own radial direction through the dielectric elastic layer 10, and brake the object moving in the receiving cavity 11.

[0028] Since the dielectric elastic layer 10 exerts force on the object placed in the accommodating cavity 11 through the inverse piezoelectric effect, the response speed is fast, compared with the brake driven by the magnetic field force of the motor, the response speed of the driver provided by the embodiment of the application can be improved by one to two orders of magnitude, from the millisecond level of the driver of the motor to the microsecond level, so the response speed is fast; since the dielectric elastic layer 10 itself is flexible, and the force is related to the deformation amount of itself, therefore, the applied force can be precisely controlled by applying a small current to form a voltage signal. That is, the driver can ensure precision while having good compliance, high response speed and low energy consumption.

[0029] Please continue to refer to Figure 3 In the embodiment, the dielectric elastic layer 10 can be multiple, and the multiple dielectric elastic layers 10 are stacked, the first electrode 31 and the second electrode 32 are also multiple, and the first electrode 31 and the second electrode 32 are alternately arranged on the upper and lower surfaces of the dielectric elastic layer 10, that is, as shown in Figure 3 from top to bottom, it can be first electrode 31, dielectric elastic layer 10, second electrode 32, dielectric elastic layer 10, first electrode 31, dielectric elastic layer 10… Two adjacent dielectric elastic layers 10 share one first electrode 31 or one second electrode 32 to increase the force exerted by the driver to the outside.

[0030] More specifically, the dielectric elastic layer 10 is made of materials such as silicone rubber, hydrogel, 3M's VHB series, etc. The first electrode 31 and the second electrode 32 can be flexible electrodes such as graphite electrodes, gel electrodes, etc.

[0031] Please continue to refer to Figure 2 and Figure 3The shell 20 comprises an upper end cover 21, a lower end cover 22 and a mounting cylinder 23. The dielectric elastic layer 10 is in a circular ring shape and is arranged in the mounting cylinder 23. The first electrode 31 and the second electrode 32 are in a sheet shape and are alternately arranged between two adjacent dielectric elastic layers 10. The upper end cover 21 and the lower end cover 22 are respectively arranged at two ends of the mounting cylinder 23. The upper end cover 21 and the lower end cover 22 are provided with through holes at positions corresponding to the accommodating cavity 11. The driver further comprises a first conductor 33 and a second conductor 34. The first conductor 33 and the second conductor 34 are arranged in the shell 20. The plurality of first electrodes 31 are connected to the first conductor 33. The plurality of second electrodes 32 are connected to the second conductor 34. The first connecting terminal 35 and the second connecting terminal 36 are further formed on one of the upper end cover 21 and the lower end cover 22. The first conductor 33 leads the plurality of first electrodes 31 out of the shell 20 and is connected to the first connecting terminal 35. The second conductor 34 leads the plurality of second electrodes 32 out of the shell 20 and is connected to the second connecting terminal 36. The first connecting terminal 35 and the second connecting terminal 36 can be connected to an external power supply, so as to simultaneously apply the same voltage to two ends of each dielectric elastic layer 10 and finely control the force acting on all the dielectric elastic layers 10.

[0032] Please continue to refer to Figure 3 In order to prevent the upper end cover 21 and the lower end cover 22 from affecting the movement of the dielectric elastic layer 10, a first gasket 41 is arranged between the upper end cover 21 and the uppermost dielectric elastic layer 10, and a second gasket 42 is arranged between the lower end cover 22 and the lowermost dielectric elastic layer 10. Further, the first gasket 41 and the second gasket 42 are fixed to the dielectric elastic layer 10 and cover the first electrode 31 or the second electrode 32. At this time, the first gasket 41 and the second gasket 42 can deform along with the deformation of the dielectric elastic layer 10. A lubricating layer 43 is arranged between the first gasket 41 and the upper end cover 21 and between the second gasket 42 and the lower end cover 22, so as to prevent the deformation of the first gasket 41 and the second gasket 42 from being affected by the upper end cover 21 and the lower end cover 22. The lubricating layer 43 can be a lubricating layer 43 formed of molybdenum disulfide or a phosphate material.

[0033] Figure 5 As shown in Figure 3 , a structure schematic view of the first conductor in the embodiment is shown, Figure 6 As shown in Figure 3 , a structure schematic view of the first electrode in the embodiment is shown. As Figure 3 , Figure 5 and Figure 6 shown, in the embodiment, the first conductor 33 and the second conductor 34 are arranged between the side wall of the dielectric elastic layer 10 and the shell 20. The first conductor 33 and the second conductor 34 (the shape of the first conductor 33 is the same as that of the second conductor 34, Figure 5Only the shape of the first conductor 33 is shown) are semicylindrical, the arc of which is adapted to the arc of the inner side wall of the mounting cylinder 23, and the first conductor 33 is filled with an insulator 37 between the first conductor 33 and the second conductor 34, that is, the first conductor 33, the second conductor 34 and the insulator 37 together form a complete cylinder and cover the outer side wall of the dielectric elastic layer 10.

[0034] The first electrode 31 and the second electrode 32 Figure 6 Only the structure of the first electrode 31 is shown, and the shape of the first electrode 31 is the same as that of the second electrode 32) are annular electrode sheets, so as to ensure the uniformity of the voltage at each part of the dielectric elastic layer 10. Further, a first radius circumferential section 381 and a second radius circumferential section 382 are formed on the outer circumference of the annular electrode sheet, the radius of the first radius circumferential section 381 is greater than that of the second radius circumferential section 382, and the first radius circumferential section 381 of the first electrode 31 and the second electrode 32 respectively faces the first conductor 33 and the second conductor 34, that is, as shown in Figure 3 , the first radius circumferential section 381 of the plurality of first electrodes 31 all faces the right side of Figure 3 , and the first radius circumferential section 381 of the plurality of second electrodes 32 all faces the left side of Figure 3 , and the structure is such that the first electrode 31 can be connected to the first conductor 33 through the first radius circumferential section 381 thereof, and the second radius circumferential section 382 of the first electrode 31 is not connected to the second conductor 34 due to the shorter radius, and similarly, the first radius circumferential section 381 of the second electrode 32 is connected to the second conductor 34, and the second radius circumferential section 382 is spaced apart from the first conductor 33. This can ensure the contact between the first electrode 31 and the second electrode 32 and the first conductor 33 and the second conductor 34.

[0035] In use, the voltage of an external power source can be applied to the first electrode 31 and the second electrode 32 through the first conductor 33 and the second conductor 34 respectively by contacting the external power source with the first connecting terminal 35 and the second connecting terminal 36, and the dielectric elastic layer 10 will deform and extend into the accommodating cavity 11 by forming a voltage difference on the first electrode 31 and the second electrode 32, so as to form a holding force on the parts placed in the accommodating cavity 11, to grab the parts or to brake the moving parts.

[0036] In summary, the present application sets the dielectric elastic layer 10, and sets the first electrode 31 and the second electrode 32 on the upper and lower sides of the dielectric elastic layer 10, and uses the inverse piezoelectric effect of the dielectric elastic layer 10 to apply a force to the object placed in the accommodating cavity 11, so the response speed of the driver is faster, and since the dielectric elastic layer 10 itself is flexible and the force is related to the deformation amount of the dielectric elastic layer 10, so the applied force can be precisely controlled by controlling the applied voltage.

[0037] The application further provides a flexible radial driving system, comprising a rod, a power supply, a control unit and the flexible radial driver, the rod is arranged in the accommodating cavity 11, the first electrode 31 and the second electrode 32 are connected with the power supply, and the control unit controls the current or voltage transmitted by the power supply to the first electrode 31 and the second electrode 32.

[0038] The driving system can grab the rod arranged in the accommodating cavity 11 through the dielectric elastic layer 10, or brake the rod moving in the accommodating cavity 11. The control unit controls the voltage or current applied to the first electrode 31 and the second electrode 32 through the power supply, so as to control the force applied to the rod by the dielectric elastic layer 10, and more finely control the driving force.

[0039] Since the dielectric elastic layer 11 is flexible, when the rod arranged therein is controlled, the dielectric elastic layer 10 can reduce the area of the accommodating cavity 11 to contact the rod, so that the cross section of the rod can not be limited to a regular circular or polygonal shape, and the dielectric elastic layer 10 can apply stable force to the rod with irregular cross section through its own deformation.

[0040] In summary, the driving system provided by the application uses the inverse piezoelectric effect of the dielectric elastic layer 10 to apply force to the rod arranged in the accommodating cavity 11, so that the response speed of the driving system is faster; since the dielectric elastic layer 10 itself is flexible and its force is related to its deformation, the control unit can control the voltage or current to precisely control the force applied to the rod, and the energy consumption is low.

[0041] The above is only the preferred embodiment of the application, and does not limit the application in any form. Although the application has been disclosed as above, it is not intended to limit the application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the application. Any simple modification, equivalent change and modification of the above embodiments based on the technical essence of the application are still within the scope of the technical solution of the application.

Claims

1. A dielectric elastomer-based flexible radial drive, characterized by: The dielectric elastomer layer is made of a dielectric elastomer material, the shell, the first electrode and the second electrode, a middle part of the dielectric elastomer layer is formed with a receiving cavity penetrating the upper and lower surfaces of the dielectric elastomer layer, the dielectric elastomer layer is arranged in the shell, the upper and lower end walls and the inner side wall of the shell form a constraint to the dielectric elastomer layer, the first electrode and the second electrode are arranged on both sides of the dielectric elastomer layer, the dielectric elastomer layer is multiple, the multiple dielectric elastomer layers are stacked, the first electrode and the second electrode are multiple, the multiple first electrodes and the second electrodes are alternately arranged on the upper and lower surfaces of the dielectric elastomer layer, two adjacent dielectric elastomer layers share one first electrode or one second electrode, the flexible radial driver based on the dielectric elastomer further comprises a first conductor and a second conductor, the first conductor and the second conductor are arranged in the shell, the first conductor is connected with the multiple first electrodes and leads out the first electrode from the shell, the second conductor is connected with the multiple second electrodes and leads out the second electrode from the shell, the first conductor and the second conductor are arranged between the side wall of the dielectric elastomer layer and the shell, the first conductor and the second conductor are in the shape of a semi-cylinder, and an insulator is filled between the first conductor and the second conductor, the first conductor, the second conductor and the insulator together form a complete cylinder and are wrapped outside the outer side wall of the dielectric elastomer layer. The shell comprises an upper end cover, a lower end cover and a mounting cylinder, the dielectric elastomer layer is arranged in the mounting cylinder, the upper end cover and the lower end cover are arranged at both ends of the mounting cylinder, through holes are formed in the upper end cover and the lower end cover at positions corresponding to the receiving cavity, and the first conductor and the second conductor are arranged between the outer side wall of the dielectric elastomer layer and the inner side wall of the mounting cylinder. The driver further comprises a first connection terminal and a second connection terminal, the first connection terminal and the second connection terminal are arranged on the upper end cover or the lower end cover, the first conductor connects the multiple first electrodes with the first connection terminal, and the second conductor connects the multiple second electrodes with the second connection terminal.

2. The dielectric elastomer-based flexible radial drive of claim 1, wherein: The dielectric elastomer layer is in the shape of a ring, the first electrode and the second electrode are in the shape of a sheet and are alternately arranged between two adjacent dielectric elastomer layers.

3. The dielectric elastomer-based flexible radial drive of claim 1, wherein: A first gasket is arranged between the upper end cover and the uppermost dielectric elastomer layer, and a second gasket is arranged between the lower end cover and the lowermost dielectric elastomer layer.

4. The dielectric elastomer-based flexible radial drive of claim 3, wherein: The first gasket and the second gasket are fixed on the dielectric elastomer layer and cover the first electrode and the second electrode, a lubricating layer is formed between the first gasket and the upper end cover and between the second gasket and the lower end cover.

5. The dielectric elastomer-based flexible radial drive of claim 1, wherein: The first electrode and the second electrode are both circular ring-shaped sheet electrodes, a first radius circumferential section and a second radius circumferential section are formed on the outer circumferences of the circular ring-shaped sheet electrodes, the radius of the first radius circumferential section is greater than the radius of the second radius circumferential section, the first radius circumferential section of the first electrode is connected with the first conductor, and the first radius circumferential section of the second electrode is connected with the second conductor.

6. A flexible radial drive system characterized by: The flexible radial driver, the rod body, the power supply, the control unit, and the flexible radial driver in any one of claims 1 to 5 are included, the rod body is arranged in the accommodating cavity, the first electrode and the second electrode are both connected with the power supply, and the control unit controls the current or voltage transmitted by the power supply to the first electrode and the second electrode.

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