A magnetothermal driven soft robot based on liquid crystal elastomer and its driving method

Abstract

A magnetothermal-driven soft robot based on liquid crystal elastomer and a driving method thereof include two relatively arranged soft elastic substrates, each of which has a bending zone at the center. The bending zone evenly divides the soft elastic substrate into two magnetized units. Each magnetized unit is divided into two magnetized zones by a vertical plane perpendicular to its center. Magnetic particles are evenly distributed in each magnetized zone. Both ends of the two soft elastic substrates are connected by liquid crystal elastomers to form a closed structure. The liquid crystal elastomers are bent 90 degrees when heated or illuminated, thereby driving the two magnetized units connected thereto to deflect and bending the bending zone until the magnetized units on both sides of the bending zone are at 90 degrees. The present invention realizes the rolling of the soft robot by periodically cutting off and applying the magnetic field, and the operation is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of soft robots, and in particular to a magnetothermal driven soft robot based on liquid crystal elastomer and a driving method thereof. Background Art

[0002] Soft robots use soft materials as a base and are equipped with various driving methods to achieve specific deformation of the base, thereby achieving movements such as movement, swinging, and grasping. Small-scale soft robots, as an important branch of the robotics field, are of great significance in biological hospitals, environmental protection, and disaster rescue scenarios. In the existing technology, there are many small-scale soft robots, and the driving methods of most soft robots are relatively simple. For example, Chinese patent CN117182872A discloses a soft robot, including a magnetic soft deformable structure and a temperature-responsive coating formed on its surface. The temperature-responsive coating drives the magnetic soft deformable structure to gather into a three-dimensional cage shape or unfold into a planar cross state through photothermal conversion; first, the material to be transported is placed in the magnetic soft deformable structure and made into a three-dimensional cage shape, and a rotating magnetic field of constant size is generated by continuously changing the uniform magnetic field to drive the continuous rolling of the robot. When the robot reaches the set position, it is irradiated with near-infrared light to unfold it into a planar cross state. In order to achieve the rotation of the robot, a rotating magnetic field needs to be applied to it. Summary of the Invention

[0003] The present invention provides a magnetothermal driven soft robot based on liquid crystal elastomer and a driving method thereof, which realizes the rolling of the soft robot by periodically cutting off and applying the magnetic field, and is easy to operate.

[0004] In order to achieve the above-mentioned purpose, the specific scheme adopted by the present invention is: a magnetothermal driven soft robot based on liquid crystal elastomer, comprising two relatively arranged soft elastic matrices, each soft elastic matrix having a bending zone at the center position, the bending zone evenly dividing the soft elastic matrix into two magnetized units, the magnetized unit is divided into two magnetized zones by a vertical plane perpendicular to its center position, and each magnetized zone is evenly distributed with magnetic particles; both ends of the two soft elastic matrices are connected by liquid crystal elastomers to form a closed structure, and the liquid crystal elastomer is bent 90° when heated or illuminated, so as to drive the two magnetized units connected thereto to deflect and bend the bending zone until the magnetized units on both sides of the bending zone are at 90°.

[0005] As an optimization solution for the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer: a groove is opened at the center position of the soft elastic matrix, so that a bending area is formed at the center position.

[0006] As another optimization scheme for the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer: a connecting portion is provided at the end of the soft elastic substrate, and the liquid crystal elastomer is bent to form an installation space with an open end, and the connecting portion extends into the installation space and is connected to its inner wall.

[0007] As another optimization solution for the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer: the connecting portion is connected to the inner wall of the installation space by gluing or thermal bonding.

[0008] As another optimization solution for the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer: the length ratio of the connecting portion to the magnetized region is 1:5-8.

[0009] As another optimization scheme for the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer: when the two soft elastic substrates are parallel, the two magnetization units on both sides of the connection part have the same magnetization direction, and the two magnetization units on both sides of the bending area have opposite magnetization directions.

[0010] As another optimization solution for the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer: the mass ratio of the soft elastic matrix to the magnetic particles is 1:0.1-0.5.

[0011] As another optimization solution for the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer: the length ratio of the bending zone to the magnetized zone is 1:10-15.

[0012] A driving method for a magnetocaloric driven soft robot based on liquid crystal elastomer is used to drive the above-mentioned magnetocaloric driven soft robot. The magnetocaloric driven soft robot is placed in a co-directional magnetic field. The two magnetized regions in each magnetization unit perpendicular to the magnetic field direction have opposite magnetization directions. The magnetic field is periodically cut off and applied, so that the magnetocaloric driven soft robot rolls along the direction perpendicular to the magnetic field with a certain angle as the fulcrum.

[0013] As an optimization scheme for the driving method of the above-mentioned magnetothermally driven soft robot based on liquid crystal elastomer, the cycle of cutting off and applying the magnetic field is 0.2-1s.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention provides a magnetothermal driven soft robot based on liquid crystal elastomer. The temperature is changed to deform the liquid crystal elastomer, which in turn drives the deformation of the soft elastic matrix, thereby bending the bending zone. Finally, the liquid crystal elastomer and the soft elastic matrix form a square, i.e., a square soft robot is formed. The square soft robot is placed in a co-directional magnetic field. The two magnetized regions in each magnetized unit perpendicular to the magnetic field have opposite magnetization directions. The magnetic field is periodically cut off and applied. When the magnetic field is applied, the square soft robot is subjected to a clockwise or counterclockwise torque, causing the square soft robot to roll along the direction perpendicular to the magnetic field with a certain corner as a particle. When the square soft robot rolls 45° clockwise or counterclockwise, the magnetic field is cut off. The square soft robot continues to roll due to inertia, thereby achieving continuous rolling. The square soft robot has a wide range of applications and is simple to drive. It can adapt to complex external environments and can work in narrow spaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the shape of the soft robot when two soft elastic substrates are parallel;

[0017] Figure 2 Schematic diagram of the distribution of the magnetized regions of the soft elastic matrix in Example 1;

[0018] Figure 3 and Figure 4 This is a schematic diagram of the peristaltic state of the soft robot in Example 3;

[0019] Figure 5 This is a schematic diagram of the soft robot in the first gait;

[0020] Figure 6 is a schematic diagram of the soft robot in the second gait;

[0021] Figure numerals: 1. soft elastic matrix, 101. bending region, 102. connecting portion, 103. magnetized region, 2. liquid crystal elastomer. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further elaborated in detail below in conjunction with specific embodiments. The parts that are not described and disclosed in detail in the following embodiments of the present invention should be understood as existing technologies known or should be known to those skilled in the art, such as how to combine a soft robot with a micro sensor module.

[0023] Example 1

[0024] A magnetothermal driven soft robot based on liquid crystal elastomer, such as Figure 1As shown, it includes two relatively arranged soft elastic matrices 1. The soft elastic matrix 1 is initially in a long strip structure, and the shape of the longitudinal section of the soft elastic matrix 1 is a rectangle or a square. In this embodiment, the shape of the longitudinal section of the soft elastic matrix 1 is a square; the soft elastic matrix 1 is composed of soft material and magnetic particles, and the mass ratio of the soft elastic matrix 1 to the magnetic particles is 1:0.1-0.5. In this embodiment, the mass ratio of the soft elastic matrix 1 to the magnetic particles is 1:0.2. Each soft elastic matrix 1 has a bending zone 101 at its center, and the bending zone 101 evenly divides the soft elastic matrix 1 into two magnetized units. If magnetic particles are not set at the center of the soft elastic matrix 1 to form the bending zone 101, and magnetic particles are set at the magnetized units, then the strength of the magnetized units is greater than that of the bending zone 101, and the soft elastic matrix 1 first bends at the bending zone 101; or a groove is opened at the center of the soft elastic matrix 1, so that the bending zone 101 is formed at the center; in this embodiment, a groove is opened at the center of the soft elastic matrix 1, so that the bending zone 101 is formed at the center.

[0025] The magnetization unit is divided into two magnetization zones 103 by a vertical plane perpendicular to its center position, and magnetic particles are evenly distributed in each magnetization zone 103. Both ends of the two soft elastic matrices 1 are connected by a liquid crystal elastomer 2 to form a closed structure. The length ratio of the bending zone 101 to the magnetization zone 103 is 1:10-15. In this embodiment, the length ratio of the two is 1:13. When the two soft elastic matrices 1 are parallel, the two magnetization units on both sides of the liquid crystal elastomer 2 have the same magnetization direction, and the two magnetization units on both sides of the bending zone 101 have opposite magnetization directions. That is, each soft elastic matrix 1 has four magnetization zones 103, the magnetization directions of the two magnetization zones 103 in each magnetization unit are opposite, the magnetization directions of the magnetization zones 103 on both sides of the bending zone 101 are opposite, and the magnetization directions of the corresponding magnetization zones 103 in the two soft elastic matrices 1 are the same. In this embodiment, as Figure 2 As shown, the soft elastic matrix 1 located at the top has four magnetization zones 103 from left to right, and the magnetization directions of the four magnetization zones 103 from left to right are vertically upward, vertically downward, vertically upward, and vertically downward, respectively; the soft elastic matrix 1 located at the bottom has four magnetization zones 103 from left to right, and the magnetization directions of the four magnetization zones 103 from left to right are vertically upward, vertically downward, vertically upward, and vertically downward, respectively.

[0026] The connection method between the soft elastic substrate 1 and the liquid crystal elastomer 2: the end of the soft elastic substrate 1 is provided with a connecting portion 102, such as Figure 1As shown, the lower surface of the connecting portion 102 located on the upper soft elastic base 1 is flush with the lower surface of the magnetized unit, and there is a height difference between the upper surface of the connecting portion 102 and the upper surface of the magnetized unit, so that a step is formed between the connecting portion 102 and the magnetized unit; the upper surface of the connecting portion 102 located on the lower soft elastic base 1 is flush with the upper surface of its magnetized unit, and there is a height difference between the lower surface of the connecting portion 102 and the lower surface of the magnetized unit, so that a step is formed between the connecting portion 102 and the magnetized unit. The liquid crystal elastomer 2 is bent to form an installation space with an open end, and the connecting portion 102 extends into the installation space and is connected to its inner side wall. The connecting portion 102 is connected to the inner side wall of the installation space by gluing or thermal bonding, as shown in FIG. Figure 1 As shown, the liquid crystal elastomer 2 is U-shaped, and the outer wall of the liquid crystal elastomer 2 is flush with the surface of the corresponding magnetized unit. The length ratio of the connecting portion 102 to the magnetized region 103 is 1:5-8. In this embodiment, the length ratio between the two is 1:7.

[0027] The liquid crystal elastomer 2 is bent 90° by heat or light, so as to drive the two magnetized units connected to it to deflect and bend the bending area 101 until the magnetized units on both sides of the bending area 101 are at 90°. Figure 5 As shown, a square soft robot is formed.

[0028] Example 2

[0029] A driving method for a magnetothermal driven soft robot based on liquid crystal elastomer is used to drive the magnetothermal driven soft robot in Example 1, that is, the square soft robot formed in Example 1. The square soft robot is placed in a magnetic field in the same direction. The two magnetized regions 103 in each magnetized unit perpendicular to the magnetic field have opposite magnetization directions. The magnetic field is periodically cut off and applied to make the square soft robot roll along the direction perpendicular to the magnetic field with a certain corner as a fulcrum. Specifically, the rolling process of the directional soft robot is decomposed into two gaits, wherein the first gait is as follows: Figure 5 As shown, the square soft robot is placed in a magnetic field with the magnetic field direction pointing vertically downward. At this time, the two magnetized units of the square soft robot are perpendicular to the magnetic field direction, and the force on the square soft robot is decomposed into force and torque. Specifically, the torques on the two magnetized units parallel to the magnetization direction are equal in magnitude and opposite in direction, and are balanced with each other; the forces on each magnetized unit perpendicular to the magnetization direction are opposite, forming a clockwise torque. Therefore, the square soft robot will roll with the corner at the bottom right as the fulcrum, rolling 45°, that is, entering the second gait, as shown in FIG. Figure 6As shown, at this point, the overall force on the square soft robot is balanced, and no torque is generated. Therefore, when the magnetic field is disconnected, the square soft robot continues to roll to the first gait under the action of inertia, and then begins the next cycle of movement. The rolling state enables the soft robot to move quickly, improving its working efficiency. At the same time, the liquid crystal elastomer 2 in the square robot deforms due to heat or light, enabling it to grasp or release objects.

[0030] Example 3

[0031] A method for driving a magnetothermally driven soft robot based on liquid crystal elastomers. When two soft elastic substrates (1) are parallel to each other, i.e., the soft robot is flat, an alternating magnetic field directed perpendicular to the soft elastic substrates (1) is applied to it, causing it to peristalsis. In this case, the soft robot can be combined with a microsensor module and, under the influence of the external magnetic field, peristalse into narrow spaces such as cracks in the ground or pipes for exploration. Alternatively, drugs can be attached to the inside of the soft robot, and peristalsis can be used to achieve targeted drug delivery within the body.

[0032] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A magnetothermal-driven soft robot based on liquid crystal elastomer, characterized by: The invention comprises two soft elastic substrates (1) arranged opposite to each other, each soft elastic substrate (1) having a bending zone (101) at its center, the bending zone (101) evenly dividing the soft elastic substrate (1) into two magnetized units (103), the magnetized unit (103) being divided into two magnetized zones by a vertical plane perpendicular to its center, and each magnetized zone having magnetic particles evenly distributed therein; both ends of the two soft elastic substrates (1) are connected by a liquid crystal elastomer (2) to form a closed structure, the liquid crystal elastomer (2) being bent by 90° when heated or irradiated with light, so as to drive the two magnetized units (103) connected thereto to deflect and bend the bending zone (101), until the magnetized units (103) on both sides of the bending zone (101) are at 90°; A groove is provided at the center of the soft elastic base (1), so that a bending area (101) is formed at the center; The end of the soft elastic base (1) is provided with a connecting portion (102), the liquid crystal elastomer (2) is bent to form an installation space with an open end, and the connecting portion (102) extends into the installation space and is connected to the inner side wall thereof; When the two soft elastic substrates (1) are parallel, the two magnetized units (103) on both sides of the connecting portion (102) have the same magnetization direction, and the two magnetized units (103) on both sides of the bending region (101) have opposite magnetization directions.

2. The magnetothermal driven soft robot based on liquid crystal elastomer according to claim 1, characterized in that: The connecting portion (102) is connected to the inner wall of the installation space by gluing or thermal bonding.

3. The magnetothermal driven soft robot based on liquid crystal elastomer according to claim 1, characterized in that: The length ratio of the connecting portion (102) to the magnetized region is 1:5-8.

4. The magnetothermal driven soft robot based on liquid crystal elastomer according to claim 1, characterized in that: The mass ratio of the soft elastic matrix (1) to the magnetic particles is 1:0.1-0.

5.

5. The magnetothermal driven soft robot based on liquid crystal elastomer according to claim 1, characterized in that: The length ratio of the bending region (101) to the magnetized region is 1:10-15.

6. A method for driving a magnetocaloric soft robot based on a liquid crystal elastomer, for driving the magnetocaloric soft robot according to any one of claims 1 to 5, characterized in that: The magnetocaloric driven soft robot is placed in a magnetic field in the same direction, and the two magnetized regions in each magnetization unit (103) perpendicular to the magnetic field have opposite magnetization directions. The magnetic field is periodically cut off and applied, so that the magnetocaloric driven soft robot rolls along the direction perpendicular to the magnetic field with a certain angle as a fulcrum.

7. The driving method of a magnetothermal driven soft robot based on liquid crystal elastomer according to claim 6, characterized in that: The cycle of cutting off and applying the magnetic field is 0.2-1s.

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