An electro-hydro-elastic wheel

Abstract

The application provides an electric liquid crystal elastomer wheel, which comprises a wheel frame, liquid crystal elastomer drivers, conductive sheets and a conductive plane; the wheel frame is made of flexible material; the wheel frame is connected with a connecting piece at the center of the wheel frame through a plurality of liquid crystal elastomer drivers; a plurality of the conductive sheets are distributed at intervals on the outside of the wheel frame, and the conductive sheets correspond to the liquid crystal elastomer drivers one by one; each conductive sheet is electrically connected with the liquid crystal elastomer drivers corresponding to the adjacent conductive sheets; the connecting piece is electrically connected with the liquid crystal elastomer drivers, and is used for providing electric energy for the deformation of the liquid crystal elastomer drivers; the conductive plane is laid under the wheel frame along the moving direction of the wheel; in the rolling process of the wheel frame, the corresponding liquid crystal elastomer drivers are deformed by the on-off of different conductive sheets and the conductive plane, so as to drive the wheel to roll. The application can realize the continuous directional motion of a soft robot.

Description

Technical Field

[0001] This invention relates to the field of flexible wheels or walking robots, and particularly to an electric liquid crystal elastomer wheel. Background Technology

[0002] Electricity, as the most common energy source in human society, offers advantages over heat or light stimulation, including convenience, cleanliness, low cost, and high adjustability, making it the preferred driving energy source for modern equipment. The direct conversion of electrical energy into mechanical work is of great significance for the practical application of electrically driven liquid crystal elastomer materials.

[0003] In recent decades, attempts have been made to obtain innovative electrically driven liquid crystal elastomer actuators. A typical strategy is to achieve indirect thermal actuation based on Joule heating by doping the liquid crystal elastomer material with inorganic conductive materials (i.e., graphite fibers and carbon nanotubes). Although inorganic conductive nanomaterials can effectively improve the conductivity of the entire liquid crystal elastomer material, they inevitably sacrifice the mechanical properties of the material and increase the cost and complexity of the fabrication scheme. Another effective method for developing electroactuators is to coat the surface of the electroactuator with a conductive layer to form a bilayer composite material. Recently, several novel electrostrictive materials have been prepared by coating the surface of the electroactuator with conductive layers using techniques such as spin coating and electron beam evaporation. In summary, indirect thermal actuation based on Joule heating has greatly promoted the development and application of liquid crystal elastomer electroactuators.

[0004] However, creating electrically driven liquid crystal elastomer soft robot systems still faces several challenges, such as durable actuator systems and continuous robot motion without human control of the excitation source. These limitations restrict the practical application of electrically driven liquid crystal elastomer materials. A particularly significant technical limitation is that electrically driven liquid crystal elastomer actuators typically achieve periodic electrical energy input by manually controlling the switching of the excitation source, thereby enabling the soft robot to generate continuous autonomous motion. This approach inevitably increases the control complexity and cost of electrically driven liquid crystal elastomer soft robots. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an electric liquid crystal elastomer wheel. The provided electric liquid crystal elastomer wheel rotates by the uneven contraction of a liquid crystal elastomer actuator, overcoming the problem of "artificial electrical energy oscillation input" control of electric-driven liquid crystal elastomer actuators, and realizing continuous directional movement of soft robots.

[0006] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0007] An electric liquid crystal elastomer wheel includes a wheel frame, a liquid crystal elastomer actuator, a conductive sheet, and a conductive plane.

[0008] The wheel frame is made of a flexible material; the wheel frame is connected to a connector located at the center of the wheel frame via a plurality of liquid crystal elastomer actuators; a plurality of conductive sheets are spaced apart on the outside of the wheel frame, and each conductive sheet corresponds one-to-one with a liquid crystal elastomer actuator; each conductive sheet is electrically connected to the liquid crystal elastomer actuator corresponding to its adjacent conductive sheet; the connector is electrically connected to the liquid crystal elastomer actuator to provide electrical energy for the deformation of the liquid crystal elastomer actuator; the conductive plane is laid under the wheel frame along the wheel movement direction.

[0009] During the rolling process of the wheel frame, different conductive sheets and conductive planes are alternately switched on and off, causing the corresponding liquid crystal elastomer actuators to deform and drive the wheel to roll.

[0010] Furthermore, the wheel frame is made of polyethylene terephthalate.

[0011] Furthermore, the liquid crystal elastomer actuator includes a liquid crystal elastomer actuation layer, a liquid metal electrothermal layer, and an encapsulation layer; one end of the liquid metal electrothermal layer is electrically connected to a connector, and the other end of the liquid metal electrothermal layer is electrically connected to the conductive sheet corresponding to the adjacent liquid crystal elastomer actuator; the liquid metal electrothermal layer is encapsulated on the liquid crystal elastomer actuation layer by the encapsulation layer, and the liquid crystal elastomer actuation layer is caused to contract and deform by electrically stimulating the liquid metal electrothermal layer.

[0012] Furthermore, the liquid metal in the liquid metal heating layer is gallium indium tin liquid metal.

[0013] Furthermore, the encapsulation layer is a polyimide encapsulation layer.

[0014] Furthermore, the conductive plane is a gold foil conductive plane.

[0015] Furthermore, the connector is a polyimide connector, and one end of the connector is connected to an external power source.

[0016] Furthermore, each conductive sheet is connected to the liquid crystal elastomer driver corresponding to its adjacent conductive sheet via a wire; the wire is disposed inside the wheel frame.

[0017] Furthermore, each conductive sheet and the liquid crystal elastomer actuator corresponding to its adjacent conductive sheet constitute an elastic actuator. By contacting the conductive plane with the conductive sheet in the elastic actuator directly below the wheel frame, a closed path is formed, causing the elastic actuator to contract and deform, driving the center of mass of the wheel frame to deflect to one side. The rotation of the wheel frame causes the conductive sheet in the elastic actuator to separate from the conductive plane, thus de-energizing and resetting the elastic actuator.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. The electric liquid crystal elastomer wheel of the present invention provides an electric liquid crystal elastomer wheel that rotates by uneven contraction of a liquid crystal elastomer actuator, which overcomes the problem of "artificial electrical energy oscillation input" control of an electric drive liquid crystal elastomer actuator and realizes continuous directional movement of a soft robot.

[0020] 2. In the electric liquid crystal elastomer wheel of the present invention, each conductive sheet is electrically connected to the liquid crystal elastomer actuator corresponding to its adjacent conductive sheet. A closed circuit is formed by the conductive plane contacting the conductive sheet in the elastic actuator directly below the wheel frame, causing the elastic actuator to contract and deform, driving the center of mass of the wheel frame to deflect to one side, thereby realizing the directional rotation of the wheel frame.

[0021] 3. The electric liquid crystal elastomer wheel of the present invention utilizes the rotation of the wheel to cause at least one elastic actuator to contract, while the remaining elastic actuators are either in their initial state or about to transform into their initial state after power failure, thereby enabling continuous directional movement. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For those skilled in the art, it is obvious that other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the electric liquid crystal elastomer wheel structure described in this invention.

[0024] Figure 2 This is a schematic diagram of the liquid crystal elastomer driver structure described in this invention;

[0025] Figure 3 This is a schematic diagram of the electric liquid crystal elastomer wheel of the present invention rotating autonomously on a conductive plane;

[0026] Figure 4 This is a schematic diagram illustrating the principle of autonomous rotation of the electric liquid crystal elastomer wheel described in this invention.

[0027] In the picture:

[0028] 10-Wheel frame; 11-Liquid crystal elastomer actuator; 111-Liquid crystal elastomer actuation layer; 112-Liquid metal electrothermal layer; 113-Encapsulation layer; 12-Conductive sheet; 13-Wire; 14-Connector; 15-Conductive plane. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] like Figure 1 As shown, the electric liquid crystal elastomer wheel of the present invention includes a wheel frame 10, a liquid crystal elastomer driver 11, a conductive sheet 12, and a conductive plane 15; the wheel frame 10 is made of a flexible material; the wheel frame 10 is a flexible material made of polyethylene terephthalate.

[0033] The wheel frame 10 is connected to the connector 14 located at the center of the wheel frame 10 via a plurality of liquid crystal elastomer actuators 11. A plurality of conductive sheets 12 are spaced apart on the outside of the wheel frame 10, and each conductive sheet 12 corresponds one-to-one with a liquid crystal elastomer actuator 11. Each conductive sheet 12 is electrically connected to the liquid crystal elastomer actuator 11 corresponding to its adjacent conductive sheet 12. This can be understood as each conductive sheet 12 being electrically connected to the liquid crystal elastomer actuator 11 corresponding to either its left or right side conductive sheet 12; that is, it can only be the left-side conductive sheet 12 or all of them are right-side conductive sheets 12. The connector 14 is electrically connected to the liquid crystal elastomer actuator 11 to provide electrical energy for the deformation of the liquid crystal elastomer actuator 11. The conductive plane 15 is laid under the wheel frame 10 along the wheel's moving direction; the conductive plane 15 is a gold foil conductive plane. During the rolling process of the wheel frame 10, different conductive sheets 12 are alternately switched on and off with the conductive plane 15, causing the corresponding liquid crystal elastomer actuator 11 to deform, thereby driving the wheel to roll.

[0034] like Figure 2 As shown, the liquid crystal elastomer actuator 11 includes a liquid crystal elastomer actuation layer 111, a liquid metal electrothermal layer 112, and an encapsulation layer 113. One end of the liquid metal electrothermal layer 112 is electrically connected to a connector 14, and the other end of the liquid metal electrothermal layer 112 is electrically connected to the conductive sheet 12 corresponding to the adjacent liquid crystal elastomer actuator 11. The liquid metal electrothermal layer 112 is encapsulated on the liquid crystal elastomer actuation layer 111 by the encapsulation layer 113. By electrically stimulating the liquid metal electrothermal layer 112, the liquid crystal elastomer actuation layer 111 is caused to contract and deform. The liquid metal in the liquid metal electrothermal layer 112 is gallium indium tin liquid metal. The encapsulation layer 113 is a polyimide encapsulation layer.

[0035] The connector 14 is a polyimide connector, and one end of the connector 14 is connected to an external power source.

[0036] To facilitate and reduce the load on the wheel frame 10, each conductive sheet 12 is connected to the liquid crystal elastomer driver 11 corresponding to its adjacent conductive sheet 12 via a wire 13; the wire 13 is disposed inside the wheel frame 10.

[0037] Each conductive sheet 12 and its adjacent liquid crystal elastomer actuator 11 constitute an elastic actuator. The conductive plane 15 contacts the conductive sheet 12 in the elastic actuator directly below the wheel frame 10 to form a closed circuit, causing the elastic actuator to contract and deform, causing the center of mass of the wheel frame 10 to deflect to one side. The rotation of the wheel frame 10 causes the conductive sheet 12 in the elastic actuator to separate from the conductive plane 15, thereby de-energizing and resetting the elastic actuator.

[0038] Example 1

[0039] like Figure 1 and Figure 2 As shown, the electric liquid crystal elastomer wheel of this embodiment includes an annular wheel frame 10 made of a 0.1mm thick polyethylene terephthalate sheet with a diameter of 80mm. A connector 14 is provided at the center of the wheel frame 10. The connector 14 is supported by polyimide material and has eight sets of connecting ends arranged circumferentially. Each set of connecting ends is provided with a liquid crystal elastomer driver 11. The other end of the liquid crystal elastomer driver 11 is connected to the inner wall of the wheel frame 10. The eight sets of liquid crystal elastomer drivers 11 are evenly spaced and arranged in a spoke-like manner. The adjacent sets of liquid crystal elastomer drivers are arranged at a 45° angle. Each set of liquid crystal elastomer drivers is approximately plate-shaped with a length and width of 40*10 mm.

[0040] In order to form a complete circuit path with the liquid crystal elastomer actuator 11, a conductive sheet 12 is provided on the outside of the wheel frame 10 corresponding to each group of liquid crystal elastomer actuators 11. The conductive sheet 12 is attached to the wheel frame. Each conductive sheet 12 is electrically connected to the adjacent group of liquid crystal elastomer actuators 11 on the right side through a wire 13. The wire 13 is located on the inside of the wheel frame. The two adjacent groups of conductive sheets 12 are not connected to each other, so that eight independent circuits are formed between the eight groups of liquid crystal elastomer actuators 11 and the corresponding conductive sheets 12 and wires 13.

[0041] The liquid crystal elastomer actuator 11 is composed of a liquid crystal elastomer actuation layer 111, a liquid metal electrothermal layer 112 and an encapsulation layer 113 arranged sequentially, wherein the liquid metal in the liquid metal electrothermal layer 112 is gallium indium tin liquid metal, and the encapsulation layer 113 is a polyimide encapsulation layer.

[0042] Connector 14 is connected to an external power supply. When the power is on, such as Figure 3 and Figure 4 As shown, the conductive plane 15 laid flat below the wheel frame 10 and the conductive sheet 12 located directly below the wheel form a complete circuit. The conductive plane 15 is made of gold foil. At this time, the liquid metal in the liquid crystal elastomer vehicle actuator 11 generates Joule heat, thereby activating the liquid crystal elastomer actuator at the lower right 45° to generate contraction deformation, causing the center of mass of the wheel frame 10 to deflect to the right and generate rotation. As the wheel frame 10 rotates, it generates a new conductive circuit. The next liquid crystal elastomer actuator is activated and contracts, while the previous one cools down and returns to its original length because the circuit is broken. This process continues, generating autonomous wheel motion without the need for human control of the excitation source dynamic input. By applying the electric liquid crystal elastomer wheel of this application to the field of soft robots, continuous directional motion of soft robots can be realized.

[0043] This embodiment provides a method for preparing a liquid crystal elastomer. 2 grams of liquid crystal mesocrystalline material (RM257) are added to 0.8 grams of toluene and heated at 80°C for 5-10 minutes to dissolve the mixture. A mixed solution of 0.4578 grams of 2,2'-(1,2-ethylenedioxydiethyl)diethylthiol (EDDET) and 0.1085 grams of pentaerythritol tetrakis(3-mercaptopropionic acid) ester (PETMP) is added and stirred with a magnetic stirrer for 2 minutes. After thorough mixing, 0.0128 grams of the photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (HHMP) is added. Dipropylamine (DPA) and toluene are diluted at a ratio of 1:10 to obtain a diluted catalyst solution. 0.284 grams of the diluted catalyst are added to the prepared solution and mixed thoroughly. The solution is placed in a vacuum chamber for 2 minutes to remove air bubbles generated during mixing. The mixture is poured into a rectangular glass mold and placed at room temperature in the dark for 12 hours. Then, the rectangular glass mold was placed in a vacuum oven at 80°C for solvent evaporation. After 24 hours, a loosely cross-linked liquid crystal elastomer film was obtained. The loosely cross-linked LCE film was pre-stretched and irradiated with ultraviolet light. After 20 minutes, the final cured liquid crystal elastomer film with internal liquid crystal media arrangement was obtained. This film is the liquid crystal elastomer actuation layer 111 in the liquid crystal elastomer actuator in Example 1.

[0044] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0045] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electric liquid crystal elastomer wheel, characterized in that, It includes a wheel frame (10), a liquid crystal elastomer actuator (11), a conductive sheet (12), and a conductive plane (15); The wheel frame (10) is made of flexible material; the wheel frame (10) and the connector (14) located at the center of the wheel frame (10) are connected by a plurality of liquid crystal elastomer actuators (11); a plurality of conductive sheets (12) are spaced apart on the outside of the wheel frame (10), and the conductive sheets (12) correspond one-to-one with the liquid crystal elastomer actuators (11); each conductive sheet (12) is electrically connected to the liquid crystal elastomer actuator (11) corresponding to its adjacent conductive sheet (12); the connector (14) is electrically connected to the liquid crystal elastomer actuator (11) to provide electrical energy for the deformation of the liquid crystal elastomer actuator (11); the conductive plane (15) is laid under the wheel frame (10) along the wheel movement direction. During the rolling process of the wheel frame (10), different conductive sheets (12) and conductive planes (15) are alternately switched on and off, causing the corresponding liquid crystal elastomer actuators (11) to deform and drive the wheel to roll.

2. The electric liquid crystal elastomer wheel according to claim 1, characterized in that, The wheel frame (10) is made of polyethylene terephthalate.

3. The electric liquid crystal elastomer wheel according to claim 1, characterized in that, The liquid crystal elastomer actuator (11) includes a liquid crystal elastomer actuation layer (111), a liquid metal electrothermal layer (112), and an encapsulation layer (113). One end of the liquid metal electrothermal layer (112) is electrically connected to a connector (14), and the other end of the liquid metal electrothermal layer (112) is electrically connected to the conductive sheet (12) corresponding to the adjacent liquid crystal elastomer actuator (11). The liquid metal electrothermal layer (112) is encapsulated on the liquid crystal elastomer actuation layer (111) by the encapsulation layer (113). By electrically stimulating the liquid metal electrothermal layer (112), the liquid crystal elastomer actuation layer (111) is caused to contract and deform.

4. The electric liquid crystal elastomer wheel according to claim 3, characterized in that, The liquid metal in the liquid metal heating layer (112) is gallium indium tin liquid metal.

5. The electric liquid crystal elastomer wheel according to claim 3, characterized in that, The encapsulation layer (113) is a polyimide encapsulation layer.

6. The electric liquid crystal elastomer wheel according to claim 1, characterized in that, The conductive plane (15) is a gold foil conductive plane.

7. The electric liquid crystal elastomer wheel according to claim 1, characterized in that, The connector (14) is a polyimide connector, and one end of the connector (14) is connected to an external power source.

8. The electric liquid crystal elastomer wheel according to claim 1, characterized in that, Each conductive sheet (12) is connected to the liquid crystal elastomer driver (11) corresponding to its adjacent conductive sheet (12) via a wire (13); the wire (13) is disposed inside the wheel frame (10).

9. The electric liquid crystal elastomer wheel according to claim 1, characterized in that, Each conductive sheet (12) and its adjacent liquid crystal elastomer actuator (11) constitute an elastic actuator. The conductive plane (15) contacts the conductive sheet (12) in the elastic actuator directly below the wheel frame (10) to form a closed circuit, causing the elastic actuator to contract and deform, causing the center of mass of the wheel frame (10) to deflect to one side. The rotation of the wheel frame (10) causes the conductive sheet (12) in the elastic actuator to separate from the conductive plane (15), thus de-energizing and resetting the elastic actuator.

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