Flexible drive

Abstract

The application discloses a flexible driver, which is knitted by liquid crystal fibers with preset deformation orientation, and comprises a first area and a second area connected with each other, the first area comprises a plurality of first columns arranged along a first direction, each first column comprises a plurality of first loops arranged along a second direction, the second area comprises a plurality of second columns arranged along the first direction, the plurality of second columns comprises a plurality of first sub-columns and a plurality of second sub-columns arranged alternately along the first direction, the first sub-columns and the second sub-columns respectively comprise a plurality of first loops and a plurality of second loops arranged along the second direction, the first loops and the second loops are arranged in opposite directions, the first direction intersects the second direction, and the first area is bent in opposite directions and the second area is inwards contracted in the first direction and the second direction under certain physical or chemical stimulation. The flexible driver has high production efficiency, recycling efficiency and good deformation capacity.

Description

Technical Field

[0001] This application belongs to the field of liquid crystal elastomer technology, and particularly relates to a flexible actuator. Background Technology

[0002] Liquid crystal elastomers (LCEs) are cross-linked polymer networks that exhibit both the anisotropy of liquid crystals (LCs) and the flexibility of polymers. Among the many smart materials used to construct flexible actuators, LCEs stand out due to their ability to undergo significant reversible deformation in response to external stimuli. This deformation originates from the change in the orderliness of the liquid crystal (LC) building blocks caused by the liquid crystal phase-isotropic phase transition. Therefore, LCE actuators with predetermined geometries and customized deformation capabilities require inducing specific orientations of the LC building blocks within the LCE to perform specific functions.

[0003] Among existing methods for manufacturing LCE actuators, additive manufacturing demonstrates significant advantages in the controllability of LC orientation and actuator molding, enabling the attribution of complex structures and deformation capabilities to LCE actuators. For example, Direct Ink Writing (DIW) technology orients LC building blocks through shear forces during molding, and the local orientation direction and actuator structure can be precisely controlled by adjusting printing parameters. However, current common processing methods for LCE actuators employ chemical crosslinking to fix the LC base orientation and actuator structure, resulting in their non-recyclability. While introducing dynamic covalent bonds can partially reshape the orientation and shape of LCE actuators, the activation temperature of these dynamic covalent bonds typically needs to be set very high to avoid interference with the LCE's driving temperature and to accelerate the dynamic bond exchange rate. This design leads to a time-consuming and demanding process for reshaping orientation and shape, and the reshaping process can cause high-temperature aging of the material.

[0004] Therefore, how to make LCE actuators have high production efficiency, diverse deformation capabilities and good recyclability has become an important issue in this field. Summary of the Invention

[0005] This application provides a flexible actuator with high production efficiency, recycling efficiency, good deformation capability, and scalability of structure and function.

[0006] This application provides a flexible actuator, which is knitted from liquid crystal fibers. The liquid crystal fibers are linear liquid crystal elastomers with a preset deformation orientation. The flexible actuator includes a first region and a second region connected to each other. The first region includes a plurality of first columns arranged along a first direction, and each first column includes a plurality of first coils arranged along a second direction. The second region includes a plurality of second columns arranged along the first direction, and the plurality of second columns include a plurality of first sub-columns and a plurality of second sub-columns arranged alternately along the first direction. Each first sub-column includes a plurality of first coils arranged along the second direction, and each second sub-column includes a plurality of second coils arranged along the second direction. The knitting directions of the first coils and second coils are opposite, and the first direction intersects the second direction. Under specific physical or chemical stimulation, the first region of the flexible actuator bends in opposite directions in the first and second directions, and the second region contracts inward in the first and second directions.

[0007] In some embodiments, in the first region, each first column includes an equal number of first coils, and the first coils of adjacent first columns are aligned in a first direction.

[0008] In some embodiments, in the second region, the number of first coils in each first sub-column and the number of second coils in each second sub-column are equal, and the first and second coils of adjacent first and second sub-columns are aligned in a first direction.

[0009] In some embodiments, in the first region, each first column includes a plurality of first coils of equal number, the first region includes a plurality of first sub-regions arranged along a first direction, each first sub-region includes at least one first column, in each first sub-region, the first coils of adjacent first columns are aligned in the first direction, and the plurality of first sub-regions are staggered in the second direction at a distance of at least one first coil.

[0010] In some embodiments, a plurality of first regions and a plurality of second regions are arranged alternately along a second direction.

[0011] In some embodiments, in the second direction, each first column corresponds one-to-one with each second column and is connected to each other.

[0012] In some embodiments, the second region includes an end region located at both ends of the flexible actuator along a second direction, with one end connected to the first region and the other end being a free end; in the end region, along the first direction from the center of the flexible actuator to the outside of the flexible actuator, the size of the second column gradually decreases in the second direction, and the first coils and second coils of adjacent first sub-columns and second sub-columns are aligned and arranged in the first direction.

[0013] In some embodiments, under specific physical or chemical stimuli, the greater the number of first coils in the first column, the greater the bending angle of the first region.

[0014] In some embodiments, under specific physical or chemical stimuli, the greater the distance between the multiple first sub-regions staggered in the second direction, the smaller the bending angle of the first region.

[0015] In some embodiments, the flexible actuator has a centrosymmetric structure.

[0016] The flexible actuator of this application embodiment is knitted from liquid crystal fibers of a linear liquid crystal elastomer with a preset deformation orientation. Liquid crystal fibers are easy to prepare, have high production efficiency, and the flexible actuator can be easily disassembled back into liquid crystal fibers for recycling. During the knitting process of the flexible actuator, different knitting methods are used in the interconnected first and second regions. Each of the multiple first columns arranged along a first direction in the first region includes multiple first coils arranged along a second direction. The multiple second columns arranged along the first direction in the second region include multiple first sub-columns and multiple second sub-columns arranged alternately along the first direction. Each first sub-column and each second sub-column respectively includes multiple first coils and second coils arranged along the second direction. The first coils and second coils have opposite knitting directions, and the first and second directions intersect. Under specific physical or chemical stimuli, the first region can bend along the first direction, and the second region can contract inward. By setting first and second regions with different deformation modes under specific physical or chemical stimuli, the flexible actuator can have multiple deformation modes as needed, exhibiting good deformation capability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the first region of a flexible actuator according to some embodiments of this application;

[0019] Figure 2 This is a schematic diagram of the structure of the second region of the flexible actuator in some embodiments of this application;

[0020] Figure 3 : Figure 3 a is a schematic diagram of the first coil; Figure 3 b is a schematic diagram of the second coil;

[0021] Figure 4 : Figure 4 a is Figure 1 A schematic diagram of the shape of the first region under normal temperature conditions; Figure 4 b is Figure 1 A schematic diagram of the shape of the first region under specific physical or chemical stimuli;

[0022] Figure 5 : Figure 5 a is Figure 2 A schematic diagram of the shape of the second region under normal temperature conditions; Figure 5 b is Figure 2 A schematic diagram of the shape of the second region under specific physical or chemical stimuli;

[0023] Figure 6 : Figure 6 a is a schematic diagram of the structure of a first example of a flexible actuator according to some embodiments of this application; Figure 6 b is Figure 6 A schematic diagram of the flexible actuator at room temperature; Figure 6 c is Figure 6 A schematic diagram of the shape of a flexible actuator under specific physical or chemical stimuli; Figure 6 d is Figure 6 The curve showing the change of the first angle of the flexible actuator in the first column with the number of the first coils in the first column under normal temperature conditions and specific physical or chemical stimuli;

[0024] Figure 7 : Figure 7 a is a schematic diagram of the structure of a second example of a flexible actuator according to some embodiments of this application; Figure 7 b is Figure 7 A schematic diagram of the flexible actuator at room temperature; Figure 7 c is Figure 7 A schematic diagram of the shape of a flexible actuator under specific physical or chemical stimuli;

[0025] Figure 8 : Figure 8 a is a structural schematic diagram of a third example of a flexible actuator according to some embodiments of this application; Figure 8 b is Figure 8 A schematic diagram of the flexible actuator at room temperature; Figure 8 c is Figure 8 A schematic diagram of the shape of a flexible actuator under specific physical or chemical stimuli; Figure 8 d is Figure 8 The curve showing the change of the first angle of the flexible actuator in a with the number of the first column under normal temperature and specific physical or chemical stimuli;

[0026] Figure 9 : Figure 9a is a structural schematic diagram of a fourth example of a flexible actuator according to some embodiments of this application; Figure 9 b is Figure 9 A schematic diagram of the flexible actuator at room temperature; Figure 9 c is Figure 9 A schematic diagram of the shape of a flexible actuator under specific physical or chemical stimuli; Figure 9 d is Figure 9 The curve showing the change of the first angle of the flexible actuator in the first column with the number of the first coils in the first column under normal temperature conditions and specific physical or chemical stimuli; Figure 9 e is Figure 9 A schematic diagram of the shape of the flexible actuator from another perspective under normal temperature conditions; Figure 9 f is Figure 9 A schematic diagram of the shape of a flexible actuator under specific physical or chemical stimuli from another perspective; Figure 9 g is Figure 9 The curve showing the change of the second angle of the flexible actuator in column a with the number of first coils in the first column under normal temperature conditions and specific physical or chemical stimuli.

[0027] Figure 10 : Figure 10 a is a structural schematic diagram of a fifth example of a flexible actuator according to some embodiments of this application; Figure 10 b is Figure 10 A schematic diagram of the flexible actuator at room temperature; Figure 10 c is Figure 10 A schematic diagram of the shape of a flexible actuator under specific physical or chemical stimuli;

[0028] Figure 11 : Figure 11 a is a structural schematic diagram of a sixth example of a flexible actuator according to some embodiments of this application; Figure 11 b is Figure 11 A schematic diagram of the flexible actuator at room temperature; Figure 11 c is Figure 11 A schematic diagram of the shape of a flexible actuator under specific physical or chemical stimuli;

[0029] Figure 12 : Figure 12 a is a structural schematic diagram of a seventh example of a flexible actuator according to some embodiments of this application; Figure 12 b is a schematic diagram of the external shape of an eighth example of a flexible actuator according to some embodiments of this application at room temperature; Figure 12 c is a schematic diagram of the shape of an eighth example of a flexible actuator according to some embodiments of this application under specific physical or chemical stimuli.

[0030] Figure label:

[0031] 100. Flexible actuator; 1. First region; 10. First sub-region; 11. First column; a. First coil; 2. Second region; 20. End region; 21. Second column; 221. First sub-column; 222. Second sub-column; b. Second coil. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0034] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, "and / or B" can represent: existing alone, existing with both B, or existing with B alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0037] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0038] In this application, "multiple" means two or more (including two).

[0039] In this application, the term "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0040] In related technologies, the fabrication methods of LCE actuators can be summarized as follows: First, the external force-induced orientation method, which involves first molding the liquid crystal elastomer using a mold, then aligning the liquid crystal cells along the stretching direction using external force, and finally fixing the liquid crystal orientation of the liquid crystal elastomer through secondary cross-linking; Second, the surface-induced method, which involves constructing a surface chemical / topological orientation layer with specific interactions with the liquid crystal cells inside the liquid crystal cell, using the anchoring effect of the liquid crystal cells' inner surface to induce the liquid crystal cells to align along a specific direction, and then cross-linking the system to fix the liquid crystal orientation of the liquid crystal elastomer; Third, the field-induced method, which involves applying an external electric or magnetic field to induce the liquid crystal cells to oriented, and then cross-linking the system to fix the liquid crystal orientation of the liquid crystal elastomer; Fourth, the ink printing writing method, which uses molten liquid crystal oligomers as printing ink, generates shear and tensile stress through a nozzle to align the liquid crystal cells along the printing direction, and then fixes the liquid crystal orientation of the liquid crystal elastomer through photocuring.

[0041] However, the applicant noted that these four methods have inherent drawbacks: In the external force-induced orientation method, the liquid crystal elastomer is oriented by external force, making it difficult to achieve diversified and high-precision control of the liquid crystal orientation, resulting in a single flexible actuator structure and deformation mode; in the surface-induced method, although it can control the complex and precise spatial orientation of liquid crystal cells, the preparation of the orientation layer is cumbersome, leading to low processing efficiency, and the thickness of the prepared flexible actuator is limited, restricting its application range; in the field-induced method, since achieving the orientation of liquid crystal cells usually requires the application of a strong electric or magnetic field, the requirements for the production environment and experimental equipment are quite stringent, and the size and structure of the prepared flexible actuator are also greatly limited; in the ink printing writing method, due to the layer-by-layer printing processing characteristics of the printing device and the low viscosity of the liquid crystal oligomers used as ink, the production efficiency is low. In addition, all of the above methods use chemical cross-linking to fix the LCE actuator structure, making it difficult to reshape the orientation and structure of the LCE actuator after processing, and thus impossible to recycle and reuse.

[0042] In addressing the aforementioned problems, fabric-based LCE actuators using fabric manufacturing technology offer a novel perspective. Fabric manufacturing technology is an additive manufacturing technique based on the physical entanglement of fibers. Utilizing axially oriented LCE fibers as building blocks, this strategy completely separates the orientation and shaping processes, thus providing high controllability over the geometry and deformation capabilities of the LCE actuator and allowing for efficient recycling and reprocessing after molding. To date, LCE fibers have been used to construct fabric-based LCE actuators through weaving and stitching. However, the deformation in these works is primarily limited to in-plane shrinkage. Transforming the one-dimensional (1D) shrinkage of LCE fibers into the more diverse three-dimensional (3D) deformation of fabric-based LCE actuators remains a challenge.

[0043] In view of this, this application provides a flexible actuator knitted from liquid crystal fibers of a linear liquid crystal elastomer with a preset deformation orientation. Liquid crystal fibers are easy to prepare, have high production efficiency, and the flexible actuator can be easily disassembled into liquid crystal fibers for recycling. During the knitting process of the flexible actuator, different knitting methods are used in the interconnected first and second regions. Each of the multiple first columns arranged along a first direction in the first region includes multiple first coils arranged along a second direction. The multiple second columns arranged along the first direction in the second region include multiple first sub-columns and multiple second sub-columns arranged alternately along the first direction. Each first sub-column and each second sub-column respectively includes multiple first coils and second coils arranged along the second direction. The first coils and second coils have opposite knitting directions, and the first and second directions intersect. Under specific physical or chemical stimuli, the first region can bend along the first direction, and the second region can contract inward. By setting first and second regions with different deformation modes under specific physical or chemical stimuli, the flexible actuator can have multiple deformation modes as needed, exhibiting good deformation capability.

[0044] This application provides a flexible actuator 100, which is made of knitted liquid crystal fibers, and the liquid crystal fibers are linear liquid crystal elastomers with a preset deformation orientation.

[0045] The liquid crystal orientation of a liquid crystal elastomer can be viewed as a change in phase or molecular structure of the liquid crystal units within the elastomer when stimulated by external factors. At the microscopic level, the liquid crystal units change their arrangement in a specific way, which in turn changes the shape of the liquid crystal elastomer at the macroscopic level, causing it to deform in accordance with a predetermined liquid crystal orientation. Optionally, the external stimulus can be a change in one or more other parameters, such as temperature or electromagnetic fields. After liquid crystal orientation, the liquid crystal elastomer can possess intrinsic mechanical anisotropy, meaning that it can have different mechanical properties in different directions. For example, it may have stronger deformation capacity in one direction and weaker deformation capacity in another, or other possible configurations.

[0046] Therefore, when the flexible actuator 100 is knitted from a liquid crystal elastomer with a preset liquid crystal orientation, applying external stimulation to the flexible actuator 100 can cause the liquid crystal elastomer to undergo a preset deformation according to its different mechanical properties in different directions, thereby deforming the flexible actuator 100. Specific physical or chemical stimulation can be applied to the flexible actuator 100. In some examples, physical stimulation of the flexible actuator 100 can be achieved by thermal stimulation, for example, heating the flexible actuator 100 from room temperature to 120 degrees Celsius. In other examples, chemical stimulation of the flexible actuator 100 can be achieved by light stimulation or humidity stimulation. It should be understood that the liquid crystal elastomer of the flexible actuator 100 capable of responding to chemical stimulation typically has a specific molecular structure at the microscopic level, that is, the liquid crystal units inside the liquid crystal elastomer possess groups capable of reacting to chemical stimulation. For example, when the liquid crystal cells inside the liquid crystal elastomer have photoresponsive groups, these groups can undergo isomerization in response to light stimulation. Similarly, when the liquid crystal cells inside the liquid crystal elastomer have hydrophilic groups, these groups can bind to water molecules in response to humidity stimulation, thereby changing the shape of the liquid crystal elastomer at a macroscopic level and causing the flexible actuator 100 to deform. Optionally, any other specific physical or chemical stimulation can be applied to the flexible actuator 100; this embodiment does not limit this application.

[0047] In some optional embodiments, the flexible actuator 100 can be knitted from a single liquid crystal fiber or from multiple liquid crystal fibers. In at least one liquid crystal fiber, the fibers can have the same liquid crystal orientation. For example, the liquid crystal units can be arranged along the axial direction of the liquid crystal fiber so that the liquid crystal fiber undergoes the same type of deformation at any position when stimulated by external forces, thereby achieving the preset function of the flexible actuator 100. Optionally, the length of the liquid crystal fiber can be determined according to the size requirements of the flexible actuator 100, and the diameter of the liquid crystal fiber can be between 1 μm and 5 mm.

[0048] The flexible actuator 100 includes a first region 1 and a second region 2 connected to each other. Liquid crystal fibers can be knitted in different ways within the first region 1 and the second region 2. Optionally, during the knitting process, the liquid crystal fibers to be used can be wound around a rod to facilitate knitting with knitting needles, or other equipment such as a knitting machine can be used to knit the liquid crystal fibers to form the flexible actuator 100; this embodiment does not limit the scope of the application.

[0049] Figure 1 This is a schematic diagram of the structure of the first region 1 of a flexible actuator 100 according to some embodiments of this application. Figure 1 As shown, the first region 1 includes a plurality of first columns 11 arranged along a first direction, and each first column 11 includes a plurality of first coils a arranged along a second direction.

[0050] The first direction may intersect with the second direction. For ease of explanation, in the following description, the first direction and the second direction will be referred to as the X direction and the Y direction, respectively. In some optional embodiments, the first direction and the second direction are perpendicular to each other. It should be understood that when the angle between the first direction and the second direction is 85°-95°, the first direction and the second direction can be considered perpendicular to each other. Optionally, the first direction and the second direction may also be other intersecting directions.

[0051] During the knitting process of the first region 1, the rows can be defined by the first direction X and the columns by the second direction Y. The liquid crystal fibers need to knit multiple first loops a in the first row along the first direction X, from the first first column 11 to the last first column 11. Then, they need to fold back along the first direction X from the last first column 11 to the first first column 11 and knit multiple first loops a in the second row, and so on, until each first column 11 includes a predetermined number of first loops a. That is, the first region 1 can be knitted according to the number of first loops a in each row. If multiple first columns 11 may be misaligned in the second direction Y, then the knitting is performed along the first direction X from one end of the first region 1 to the other, based on the number of first columns 11 with first loops a in that row.

[0052] Figure 2 This is a schematic diagram of the structure of the second region 2 of the flexible actuator 100 according to some embodiments of this application. For example... Figure 2 As shown, the second region 2 includes a plurality of second columns 21 arranged along the first direction X. The plurality of second columns 21 include a plurality of first sub-columns 221 and a plurality of second sub-columns 222 arranged alternately along the first direction X. Each first sub-column 221 includes a plurality of first coils a arranged along the second direction Y. Each second sub-column 222 includes a plurality of second coils b arranged along the second direction Y.

[0053] Similar to the first region 1, during the knitting process in the second region 2, the first direction X can be used as the row and the second direction Y as the column. The liquid crystal fiber needs to knit multiple loops in the first row from the first second column 21 to the last second column 21 along the first direction X. Since the first sub-column 221 and the second sub-column 222 are arranged alternately in the second region 2, the first sub-column 221 includes a first loop a and the second sub-column 222 includes a second loop b, within a row, the liquid crystal fiber needs to knit alternately with one first loop a and then one second loop b. After the first row is knitted, the liquid crystal fiber needs to fold back along the first direction X from the last second column 21 to the first second column 21, and according to the loop type of the first row, knit the second row again with one first loop a and then one second loop b... until each second column 21 includes a preset number of first loops a or second loops b.

[0054] Figure 3 a is a schematic diagram of the structure of the first coil a. Figure 3 b is a schematic diagram of the structure of the second coil b. For example... Figure 3 As shown in ab, the knitting directions of the first loop a and the second loop b are opposite.

[0055] The first loop a can be a knitted loop and the second loop b a purlted loop. When knitting the same row of loops, a knitted loop is a knitting method in which the loop of the current row passes through the loop of the previous row from below, while a purlted loop is a knitting method in which the loop of the current row passes through the loop of the previous row from above.

[0056] Optionally, the dimensions of the first coil a and the second coil b can be 2 to 10 times the diameter of the liquid crystal fiber. Preferably, the dimensions of the first coil a and the second coil b can be 2 to 5 times the diameter of the liquid crystal fiber. Within this range, the flexible actuator can be guaranteed to have good deformation capability.

[0057] Figure 4 a is Figure 1 A schematic diagram of the shape of the first region 1 under normal temperature conditions. Figure 4 b is Figure 1 A schematic diagram of the shape of region 1 under specific physical or chemical stimuli. (e.g.) Figure 4 As shown in ab, when the first region 1 is knitted with a straight needle, at room temperature, the first region 1 has arcs that are opposite to each other in the first direction X and the second direction Y, that is, it has an arc facing away from each other in the first direction X and an arc facing forward in the second direction Y.

[0058] Under specific physical or chemical stimuli, the first region 1 bends in opposite directions in the first direction X and the second direction Y. The first region 1 bends in opposite directions in the first direction X and the second direction Y. For example, the first region 1 may bend in the opposite direction in the first direction X and bend in the positive direction in the second direction Y, thereby increasing the curvature of the first region 1 in opposite directions in the first direction X and the second direction Y.

[0059] Figure 5 a is Figure 2 A schematic diagram of the shape of the second region 2 under normal temperature conditions. Figure 5 b is Figure 2 A schematic diagram of the shape of region 2 in the middle under specific physical or chemical stimuli. (e.g.) Figure 5 As shown in ab, when the second region 2 is knitted with alternating knit and purl stitches in each column, at room temperature, the second region 2 is approximately located on the same plane.

[0060] Under specific physical or chemical stimuli, the second region 2 contracts inward in the first direction X and the second direction Y, resulting in a tighter knitted structure in the second region 2.

[0061] It should be understood that the first region 1 and the second region 2 are connected to each other, and the first region 1 and the second region 2 can be knitted using the same liquid crystal fiber. That is to say, during the knitting of the same row, the knitting method can be used as the basis for distinguishing the first region 1 and the second region 2. For example, the first loop a can be used for knitting in the same row, and / or the first loop a and the second loop b can be knitted alternately. Optionally, the first region 1 and the second region 2 can also be knitted in other ways, as long as there is a difference in the knitting method. When different knitting methods are used, the first region 1 and the second region 2 can also have different deformation modes, depending on the functional requirements of the flexible actuator. This application embodiment does not limit this.

[0062] Figure 6 a is a structural schematic diagram of a first example of a flexible actuator 100 according to some embodiments of this application. Figure 6 As shown in Figure a, in the first example, along the second direction Y, two second regions 2 are connected to the two ends of the first region 1.

[0063] In some embodiments of this application, in the first region 1, each first column 11 includes an equal number of first loops a, and the first loops a of adjacent first columns 11 are aligned in the first direction X. In a first example, where each first column 11 includes an equal number of first loops a, each row within the first region 1 includes the same number of first loops a. That is, during the knitting process of the first region 1, the same number of first loops a are knitted in the same row.

[0064] In some embodiments of this application, in the second region 2, the number of first loops a in each first sub-column 221 and the number of second loops b in each second sub-column 222 are equal, and the first loops a and second loops b of adjacent first sub-columns 221 and second sub-columns 222 are aligned in the first direction X. Corresponding to the first region 1, in the first example, each row in the second region 2 includes the same number of loops. That is, when alternating the knitting of first loops a and second loops b, the total number of first loops a and second loops b in each row of the second region 2 is equal.

[0065] Optionally, in the second direction Y, each first column 11 corresponds one-to-one with each second column 21 and is connected to each other. That is, in the first example, the number of first columns 11 and second columns 21 is the same, and the first region 1 and the second region 2 have the same number of coils in the first direction X. When two second regions 2 are provided at both ends of the first region 1 along the second direction Y, each first column 11 is connected to one second column 21 at both ends, so that the flexible actuator is formed into a rectangular block.

[0066] Figure 6 b is Figure 6 A schematic diagram of the flexible actuator 100 under normal temperature conditions. Figure 6 c is Figure 6 A schematic diagram of the shape of the flexible actuator 100 under specific physical or chemical stimuli. (See diagram for example.) Figure 6 As shown in bc, in the first example, since the first region 1 itself has a certain bending angle, under normal temperature conditions, the second regions 2 located at both ends of the first region 1 have an angle that folds towards each other, with the folding angle being the first angle α. Under specific physical or chemical stimuli, the flexible actuator undergoes further bending at the first region 1 and contraction at the second region 2, causing the two second regions 2 of the flexible actuator to fold towards each other further, and the first angle α also increases accordingly.

[0067] 6d is Figure 6 The curve showing the change of the first angle of the flexible actuator 100 in column a with the number of first coils a in column 11 under normal temperature conditions and specific physical or chemical stimuli. (See figure) Figure 6 As shown in d, in some embodiments of this application, under specific physical or chemical stimuli, the more first coils a in the first column 11 there are, the greater the bending angle of the first region 1.

[0068] Figure 6In diagram d, square dots represent the variation of the first angle α with the number of first coils a in the first column 11 under normal temperature conditions, while circular dots represent the variation of the first angle α with the number of first coils a in the first column 11 under specific physical or chemical stimuli. With the vertical axis representing the first angle α and the horizontal axis representing the number C of first coils a in the first column 11 of the first region 1, the first angle α increases with the increase of the number C of first coils a in the first column 11 of the first region 1. That is, the larger the size of the first region 1 in the second direction Y, the more severe the deformation of the flexible actuator under specific physical or chemical stimuli. This allows control of the first angle α to achieve a preset deformation of the flexible actuator. Optionally, the first angle α can be located between 0 and 180°.

[0069] Figure 7 a is a structural schematic diagram of a second example of a flexible actuator 100 according to some embodiments of this application. Figure 7 b is Figure 7 A schematic diagram of the flexible actuator 100 under normal temperature conditions. Figure 7 c is Figure 7 A schematic diagram of the shape of the flexible actuator 100 under specific physical or chemical stimuli. (See diagram for example.) Figure 7 As shown in ac, in some optional embodiments, a plurality of first regions 1 and a plurality of second regions 2 are arranged alternately along the second direction Y.

[0070] Compared to the first example, the second example includes more first regions 1 and second regions 2, causing the flexible actuator to be formed as a larger rectangular block in the second direction Y. At room temperature, the flexible actuator exhibits a bent shape, but under specific physical or chemical stimuli, it bends further at the first region 1 and contracts at the second region 2, resulting in a more pronounced degree of bending. Similar to the first example, the degree of bending of the flexible actuator can be controlled by adjusting the number of first coils a in the first column 11 of each first region 1, allowing the flexible actuator to undergo a predetermined deformation.

[0071] Figure 8 a is a structural schematic diagram of a third example of the flexible actuator 100 according to some embodiments of this application. For example... Figure 8As shown in Figure a, in the third example, along the first direction X, two second regions 2 are connected to the two ends of the first region 1. In the first region 1, each first column 11 includes an equal number of first coils a, and the first coils a of adjacent first columns 11 are aligned in the first direction X. In the second region 2, the number of first coils a in each first sub-column 221 and the number of second coils b in each second sub-column 222 are equal, and the first coils a and second coils b of adjacent first sub-columns 221 and second sub-columns 222 are aligned in the first direction X. Specifically, the number of first coils a or second coils b in each first column 11 and each second column 21 is equal, meaning that each row of coils in the first region 1 and the second region 2 corresponds one-to-one.

[0072] Figure 8 b is Figure 8 A schematic diagram of the flexible actuator 100 under normal temperature conditions. Figure 8 c is Figure 8 A schematic diagram of the shape of the flexible actuator 100 under specific physical or chemical stimuli. (See diagram for example.) Figure 8 As shown in bc, the first angle α is defined as the folding angle at which the second regions 2 located at both ends of the first region 1 fold towards each other. Under specific physical or chemical stimuli, the flexible actuator bends further at the first region 1 and contracts at the second region 2, causing the two second regions 2 of the flexible actuator to fold towards each other further, and the first angle α increases accordingly.

[0073] Figure 8 d is Figure 8 The curve showing the change of the first angle of the flexible actuator 100 in column a with the number of columns 11 under normal temperature conditions and specific physical or chemical stimuli. (Example) Figure 9 As shown in d, in this embodiment of the application, under specific physical or chemical stimulation, the more the number of the first column 11, the greater the bending angle of the first region 1.

[0074] Figure 8 In diagram d, square dots represent the variation of the first angle α with the number of first columns 11 at room temperature, while circular dots represent the variation of the first angle α with the number of first columns 11 under specific physical or chemical stimuli. With the vertical axis representing the first angle α and the horizontal axis representing the number W of first columns 11 in the first region 1, the first angle α increases with the increase of the number W of first columns 11 in the first region 1. That is, the larger the size of the first region 1 in the first direction X, the more severe the deformation of the flexible actuator under specific physical or chemical stimuli. This can also be used to control the size of the first angle α, causing the flexible actuator to undergo a predetermined deformation.

[0075] Optionally, the third example may also be similar to the second example, having more first regions 1 and second regions 2 in the first direction X, such that the multiple first regions 1 and multiple second regions 2 are arranged alternately along the first direction X. The embodiments of this application will not be described in detail here.

[0076] Figure 9 a is a structural schematic diagram of a fourth example of the flexible actuator 100 according to some embodiments of this application. For example... Figure 9 As shown in Figure a, in some embodiments of this application, in the first region 1, each first column 11 includes a plurality of first coils a of equal number, the first region 1 includes a plurality of first sub-regions 10 arranged along the first direction X, each first sub-region 10 includes at least one first column 11, in each first sub-region 10, the first coils a of adjacent first columns 11 are aligned in the first direction X, and the plurality of first sub-regions 10 are staggered in the second direction Y at a distance of at least one first coil a.

[0077] In the fourth example, the first region 1 includes a plurality of first sub-regions 10, which are arranged along a first direction X and staggered sequentially along a second direction Y. The size of each first sub-region 10 may be equal or unequal, and the stagger distance of each first sub-region 10 may be equal or unequal. The first coil a located in each first sub-region 10 is aligned with each other in the first direction X and the second direction Y.

[0078] Optionally, two second regions 2 can still be set at both ends of the first region 1 along the second direction Y. The second regions 2 can be matched with the shape of the first region 1, so that each first column 11 corresponds one-to-one with each second column 21 and is connected to each other. That is to say, when the multiple first sub-regions 10 of the first region 1 are misaligned with each other, the second region 2 can also include multiple second sub-regions corresponding to each other and be set in conjunction with the first sub-regions 10. The embodiments of this application will not be described in detail here.

[0079] Figure 9 b is Figure 9 A schematic diagram of the flexible actuator 100 under normal temperature conditions. Figure 9 c is Figure 9 A schematic diagram of the shape of the flexible actuator 100 under specific physical or chemical stimuli. (See diagram for example.) Figure 9 As shown in bc, the first angle α is defined as the folding angle at which the second regions 2 located at both ends of the first region 1 fold towards each other. Under specific physical or chemical stimuli, the flexible actuator bends further at the first region 1 and contracts at the second region 2, causing the two second regions 2 of the flexible actuator to fold towards each other further, and the first angle α increases accordingly.

[0080] Figure 9 d is Figure 9The curve showing the change of the first angle of the flexible actuator 100 in column a with the number of first coils a in column 11 under normal temperature conditions and specific physical or chemical stimuli. (See figure) Figure 9 As shown in d, in some embodiments of this application, under specific physical or chemical stimulation, the greater the distance between the multiple first sub-regions 10 staggered in the second direction Y, the smaller the bending angle of the first region 1.

[0081] Figure 9 In diagram d, square dots represent the variation of the first angle α with the number of first coils a in the first column 11 under normal temperature conditions, while circular dots represent the variation of the first angle α with the number of first coils a in the first column 11 under specific physical or chemical stimuli. With the vertical axis representing the first angle α and the horizontal axis representing the number C of first coils a in the first column 11 of the first region 1, the first angle α decreases as the number C of first coils a in the first column 11 of the first region 1 increases. That is, the greater the misalignment of the multiple first sub-regions 10 in the second direction Y, the smoother the deformation of the flexible actuator under specific physical or chemical stimuli. This allows control of the first angle α to achieve a predetermined deformation of the flexible actuator. Optionally, the first angle α can be between 0 and 180°.

[0082] Figure 9 e is Figure 9 A schematic diagram of the flexible actuator 100 from another perspective under normal temperature conditions. Figure 9 f is Figure 9 A schematic diagram of the shape of the flexible actuator 100 under specific physical or chemical stimuli from another perspective. (See diagram for example.) Figure 9 As shown in ef, based on the misalignment distance of multiple first sub-regions 10 in the second direction Y and the size of the first region 1 in the first direction X, the misalignment angle of the first sub-region 10 relative to the first direction X is obtained, and the misalignment angle is taken as the second angle β.

[0083] Figure 9 g is Figure 9 The curve showing the variation of the second angle β of the flexible actuator 100 in column a with the number of first coils a in column 11 under normal temperature conditions and specific physical or chemical stimuli. Figure 9 As shown in Figure g, square dots represent the variation of the second angle β with the number of first coils a in the first column 11 under normal temperature conditions, while circular dots represent the variation of the second angle β with the number of first coils a in the first column 11 under specific physical or chemical stimuli. With the misalignment distance of the multiple first sub-regions 10 remaining constant, the second angle β increases with the increase of the number C of first coils a in the first column 11. Under normal temperature conditions and under specific physical or chemical stimuli, the second angle β remains essentially unchanged.

[0084] Figure 10 a is a structural schematic diagram of a fifth example of a flexible actuator 100 according to some embodiments of this application. Figure 10 b is Figure 10 A schematic diagram of the flexible actuator 100 under normal temperature conditions. Figure 10 c is Figure 10 A schematic diagram of the shape of the flexible actuator 100 under specific physical or chemical stimuli. (See diagram for example.) Figure 10 As shown in Figure ac, in the fifth example, multiple first regions 1 and multiple second regions 2 are arranged alternately along the first direction X. Similar to the fourth example, each first region 1 includes multiple first sub-regions 10, which are arranged along the first direction X and staggered sequentially along the second direction Y. The second regions 2 are configured to match the shape of the first regions 1.

[0085] Compared to the fourth example, the fifth example includes more first regions 1 and second regions 2. Since the first region 1 itself has a certain bending angle, the flexible actuator is curled up at room temperature. Under specific physical or chemical stimuli, the flexible actuator bends further in the first region 1 and contracts in the second region 2, making the curling of the flexible actuator more intense. Similar to the fourth example, the degree of bending of the flexible actuator can be controlled by controlling the number of first coils a in the first column 11 of each first region 1, so that the flexible actuator undergoes a preset deformation.

[0086] Figure 11 a is a structural schematic diagram of a sixth example of the flexible actuator 100 of some embodiments of this application; Figure 11 b is Figure 11 A schematic diagram of the external shape of the flexible actuator 100 under normal temperature conditions; Figure 11 c is Figure 11 A schematic diagram of the shape of the flexible actuator 100 under specific physical or chemical stimuli. (See diagram for example.) Figure 11 As shown in ac, in the sixth example, the arrangement method of the first region 1 can be combined with, for example, the first example and the fourth example, to set up the sixth example so that the flexible actuator undergoes a preset deformation. This application embodiment does not limit this.

[0087] Figure 12 Figure a is a structural schematic diagram of a seventh example of a flexible actuator 100 according to some embodiments of this application. In some embodiments of this application, the second region 2 includes an end region 20, which is located at both ends of the flexible actuator along the second direction Y, with one end connected to the first region 1 and the other end being a free end. In the end region 20, along the first direction X from the center of the flexible actuator to the outside of the flexible actuator, the size of the second column 21 gradually decreases in the second direction Y, and the first coil a and second coil b of adjacent first sub-columns 221 and second sub-columns 222 are aligned and arranged in the first direction X.

[0088] In some optional embodiments, a plurality of first regions 1 and a plurality of second regions 2 are arranged alternately along a second direction Y. The second region 2 located at the end of the flexible actuator in the second direction Y has a shape that converges inward from both sides of the flexible actuator in the first direction X, compared to the other second regions 2. This second region 2 located at the end can be considered as the end region 20. That is, in the first direction X, the number of coils gradually increases in each second column 21 from the edge to the center of the flexible actuator, while in the second direction Y, the number of coils gradually decreases in each row from the edge to the center of the flexible actuator.

[0089] At room temperature, the end regions 20 located at both ends of the flexible actuator 100 fold towards the center of the flexible actuator 100 along the second direction Y. Under specific physical or chemical stimuli, the flexible actuator bends further at the first region 1 and contracts at the second region 2, causing the end regions 20 to fold further inward into the flexible actuator, with the two ends of the flexible actuator 100 facing each other.

[0090] Figure 12 b is a schematic diagram of the external shape of an eighth example of a flexible actuator 100 according to some embodiments of this application at room temperature. Figure 12 c is a schematic diagram of the shape of an eighth example of a flexible actuator 100 according to some embodiments of this application under specific physical or chemical stimuli. Figure 12 As shown in bc, in some embodiments of this application, the flexible actuator 100 has a centrally symmetric structure.

[0091] In the eighth example, multiple settings such as Figure 12 The flexible actuator 100 of the seventh example shown in figure a is such that the end regions 20 of a plurality of flexible actuators 100 are connected to each other to form a centrosymmetric structure. In a plurality of flexible actuators such as the seventh example, at room temperature, the end region 20 of each flexible actuator folds towards the center, and under specific physical or chemical stimulation, the end regions 20 of the plurality of flexible actuators fold further towards the center, and can be connected to each other to achieve a preset deformation function.

[0092] Alternatively, in other embodiments of this application, the flexible actuator 100 may also be a non-centrosymmetric structure, and this application does not limit this.

[0093] In the above examples, the diameter of the liquid crystal fiber is 580 μm, and the diameters of the first coil a and the second coil b are 2.2 mm. The diameters of the first coil a and the second coil b are approximately 3.8 times the diameter of the liquid crystal fiber. Optionally, this size can be appropriately adjusted according to the actual application requirements, and the embodiments of this application do not impose any limitations on this.

[0094] It should be understood that the above examples are all made of liquid crystal fibers knitted together. By utilizing the different knitting methods of the liquid crystal fibers in the first region 1 and the second region 2, the first region 1 and the second region 2 have different deformation modes, so that the flexible actuator 100 undergoes a predetermined deformation. That is to say, the flexible actuator 100 is obtained by knitting liquid crystal fibers in different ways or sequences. During the manufacturing process of the flexible actuator 100, the liquid crystal fibers are deformed from a linear shape into coils arranged along the first direction X and the second direction Y. It is conceivable that after the flexible actuator 100 has performed its function, the liquid crystal fibers can be restored from the arranged coils to a linear shape to recycle the used liquid crystal fibers. Therefore, the flexible actuator 100 of the present application embodiment has good reprocessing performance. After being recycled, the liquid crystal fibers can be knitted again to form other flexible actuators 100. The present application embodiment does not limit this.

[0095] Furthermore, in some optional embodiments, multiple flexible actuators 100 can be combined with each other. For example, in the eighth embodiment, multiple flexible actuators 100 of the seventh embodiment are included, and the end regions 20 of the multiple flexible actuators 100 are joined together. In this case, the joining of the ends of adjacent flexible actuators 100 can be achieved by a knitting method or by joining the ends of adjacent flexible actuators 100 together with other liquid crystal fibers. Similarly, in other embodiments, flexible actuators 100 knitted in different ways can be combined according to specific production needs. For example, in the sixth embodiment, flexible actuators 100 of the first and fourth embodiments are included, which will not be described in detail in this application embodiment. Thus, the flexible actuators 100 of this application embodiment have good structural and functional scalability. It is conceivable that flexible actuators 100 of different structures or other functional fibrous materials and fabric materials can be combined in any feasible manner, and this application embodiment does not limit this.

[0096] In summary, the flexible actuator provided in this application embodiment is made of liquid crystal fibers knitted from linear liquid crystal elastomers with a preset deformation orientation. Liquid crystal fibers are easy to prepare, have high production efficiency, and are chemically stable, allowing for long-term storage. In the process of knitting the flexible actuator, different knitting methods are used in the interconnected first region 1 and second region 2. Each of the multiple first columns 11 arranged along the first direction X in the first region 1 includes multiple first loops a arranged along the second direction Y. The multiple second columns 21 arranged along the first direction X in the second region 2 include multiple first sub-columns 221 and multiple second sub-columns 222 arranged alternately along the first direction X. Each first sub-column 221 and each second sub-column 222 respectively includes multiple first loops a and second loops b arranged along the second direction Y. The first loops a and second loops b have opposite knitting directions, and the first direction X intersects the second direction Y. Under specific physical or chemical stimuli, the first region 1 can bend along the first direction X, and the second region 2 can contract inward. By setting the first region 1 and second region 2 to have different deformation modes under specific physical or chemical stimuli, the flexible actuator can have multiple deformation modes as needed, exhibiting good deformation capability. Furthermore, since the knitted structure is composed of physical entanglement between fibers, the flexible actuator can be easily disassembled into liquid crystal fibers for recycling. Furthermore, the porous structure of the fabric allows the LCE actuator to be further combined with functional fibers or fabrics through embroidery, knitting, weaving, and other methods, thereby further expanding its structure and function.

[0097] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A flexible driver, characterized by, The flexible actuator is made of knitted liquid crystal fibers, which are linear liquid crystal elastomers with a preset deformation orientation. The flexible actuator includes a first region and a second region connected to each other: The first region includes a plurality of first columns arranged along a first direction, and each first column includes a plurality of first coils arranged along a second direction; The second region includes a plurality of second columns arranged along the first direction, the plurality of second columns including a plurality of first sub-columns and a plurality of second sub-columns arranged alternately along the first direction, each first sub-column including a plurality of first loops arranged along the second direction, each second sub-column including a plurality of second loops arranged along the second direction, the knitting directions of the first loops and the second loops being opposite, and the first direction being orthogonal to the second direction; Under specific physical or chemical stimulation, the first region of the flexible actuator bends in opposite directions in the first and second directions, and the second region contracts inward in the first and second directions. Physical stimuli include thermal stimuli, while chemical stimuli include light stimuli or humidity stimuli.

2. The flexible driver of claim 1, wherein, In the first region, each of the first columns includes an equal number of the first coils, and the first coils of adjacent first columns are aligned in the first direction.

3. The flexible driver of claim 2, wherein, In the second region, the number of first coils in each first sub-column and the number of second coils in each second sub-column are equal, and the first coils and second coils of adjacent first sub-columns and second sub-columns are aligned in the first direction.

4. The flexible driver of claim 1, wherein, In the first region, each first column includes an equal number of first coils, the first region includes a plurality of first sub-regions arranged along the first direction, each first sub-region includes at least one first column, in each first sub-region, the first coils of adjacent first columns are aligned in the second direction, and the plurality of first sub-regions are staggered in the second direction at a distance of at least one first coil.

5. The flexible drive of claim 3 or 4, wherein, Multiple first regions and multiple second regions are arranged alternately along the second direction.

6. The flexible driver of claim 5, wherein, In the second direction, each of the first columns corresponds one-to-one with each of the second columns and is connected to each other.

7. The flexible driver of claim 2, wherein, The second region includes an end region located at both ends of the flexible actuator along the second direction, with one end connected to the first region and the other end being a free end; In the end region, along the first direction from the center of the flexible actuator to the outside of the flexible actuator, the size of the second column gradually decreases in the second direction, and the first coils and second coils of adjacent first sub-columns and second sub-columns are aligned in the first direction.

8. The flexible driver of claim 5, wherein, Under specific physical or chemical stimuli, the more first coils in the first column the flexible actuator has, the greater the bending angle of the first region.

9. The flexible driver of claim 4, wherein, Under specific physical or chemical stimulation, the greater the distance by which the multiple first sub-regions are misaligned in the second direction, the smaller the bending angle of the first region.

10. The flexible actuator according to claim 1, characterized in that, The flexible actuator has a centrosymmetric structure.

Images