A photoactuator with negative Poisson's ratio

Abstract

The present invention belongs to the field of medical device technology and relates to a negative Poisson's ratio optical actuator, comprising a negative Poisson's ratio frame, a liquid crystal elastomer sleeve, and an optical fiber. The structural unit of the negative Poisson's ratio frame is a double-headed arrow shape, which is composed of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, and the two sides of the low V-shape are equal in length. The low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape. The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and is fixedly connected to the negative Poisson's ratio frame and located in the center of the negative Poisson's ratio frame. The central axis of the liquid crystal elastomer sleeve is collinear with the optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber. The liquid crystal elastomer sleeve contracts when irradiated by infrared laser light emitted from the optical fiber, and rebounds after the infrared laser light is removed. The present invention adopts a negative Poisson's ratio structure and a light-actuated method to match the mechanical properties of the device with the contraction characteristics of the heart.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices and relates to a light actuator with a negative Poisson's ratio. Background Art

[0002] With the in-depth study of human physiological functions and the pursuit of precision in medical monitoring and treatment methods, the development of devices that can be highly matched with human organs (such as the heart) has become an important research direction.

[0003] As one of the most vital organs in the human body, the heart's contraction and relaxation processes are complex and precise physiological events, involving coordinated movements in multiple dimensions. During contraction, cardiomyocytes not only contract longitudinally (along the heart's long axis) but also synchronously contract transversely (along the heart's circumference). This multi-dimensional coordinated contraction is crucial for maintaining the heart's normal pumping function.

[0004] However, existing cardiac actuators have many deficiencies in mechanical properties and driving methods, making it difficult to meet the requirements of high matching with the heart.

[0005] Traditional cardiac actuator devices often struggle to match the mechanical properties of the heart's contraction characteristics. For example, when a patch structure made of conventional materials is circular, its mechanical properties dictate its lateral expansion during longitudinal contraction. This conflicts with the simultaneous lateral and longitudinal contraction of the myocardium, preventing the device from properly fitting to the heart. This, in turn, hinders accurate monitoring of cardiac physiological parameters and the effective treatment of heart disease.

[0006] Furthermore, most existing cardiac actuators rely on electrical drive. For example, patent publication number CN115869531B discloses an implantable ventricular assist device, which includes a telescopic sleeve that surrounds the entire heart, a main system processing mechanism, a pressure monitoring sensor assembly, and an energy source assembly. All components are electrically connected. The sleeve's knuckle structure expands when the power is off and radially rotates from the proximal end to the distal end to squeeze the heart when the power is on. The sleeve simulates the normal contraction of the myocardium, improving pumping efficiency and reducing damage to the heart. Patent publication number CN117442867A discloses a cardiac assist device and its control method, which utilizes electrostatic attraction to drive a deformable cavity to achieve assisted contraction of different cardiac regions, offering improved safety. However, while these innovative designs have addressed some shortcomings to a certain extent, electrical drive still presents some issues, including the potential for adverse effects on human tissue. For example, electrical stimulation can cause electrical damage to local tissue, leading to serious complications such as arrhythmias. In addition, the electric drive mode also has the problem of complexity in energy transmission and control, making it difficult to achieve precise and flexible control.

[0007] In short, existing cardiac actuators struggle to meet the requirements for close heart alignment. Innovation and breakthroughs in materials science and drive technology are urgently needed to develop precise, safe, and flexible cardiac actuators that closely match the physiological characteristics of the heart. Summary of the Invention

[0008] The purpose of the present invention is to solve the problems existing in the prior art and provide an optical actuator with a negative Poisson's ratio.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] A negative Poisson's ratio optical actuator comprising a negative Poisson's ratio frame, a liquid crystal elastomer sleeve, and an optical fiber;

[0011] The wall thickness of the liquid crystal elastomer sleeve is less than 100 μm. The wall thickness of the liquid crystal elastomer sleeve must be thin enough to keep up with the beating frequency of the heart.

[0012] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame by bonding or other means;

[0013] The central axis of the liquid crystal elastomer sleeve is collinear with the optical axis of the optical fiber (i.e., the central propagation direction axis of the light after it is emitted from the end face of the optical fiber), and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber;

[0014] The liquid crystal elastomer sleeve contracts when irradiated by infrared laser light emitted from the optical fiber, and rebounds after the infrared laser light is removed;

[0015] Since the central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame by bonding or the like, and therefore the negative Poisson's ratio frame contracts as the liquid crystal elastomer sleeve contracts and recovers as the liquid crystal elastomer sleeve recovers.

[0016] As the preferred technical solution:

[0017] In the negative Poisson's ratio optical actuator as described above, the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame. Such a design is conducive to ensuring a high connection strength between the liquid crystal elastomer sleeve and the negative Poisson's ratio frame, and is also conducive to the liquid crystal elastomer sleeve to fully play its role and drive the deformation of the negative Poisson's ratio frame.

[0018] In the negative Poisson's ratio optical actuator as described above, the front and rear ends of the liquid crystal elastomer sleeve coincide with the edges of the negative Poisson's ratio frame, or extend from the negative Poisson's ratio frame.

[0019] The steps for preparing the liquid crystal elastomer sleeve of the negative Poisson's ratio optical actuator are as follows:

[0020] (a) Prepare a liquid crystal elastomer solution; the liquid crystal elastomer solution is usually composed of liquid crystal monomers, a crosslinking agent, an initiator and a solvent. The liquid crystal monomers are composed of rigid mesogens and flexible spacers. Among them, the rigid mesogens are mainly benzene ring derivatives, aromatic esters or heterocyclic compounds; the flexible spacers are mainly alkyl chains, polyether chains or siloxane chains. The role of the crosslinking agent is to crosslink the liquid crystal monomers into a three-dimensional network structure, thereby giving the liquid crystal elastomer (LCE) fiber elasticity. Commonly used crosslinking agents include bifunctional monomers, Such as divinylbenzene, ethylene glycol dimethacrylate, and multifunctional monomers such as pentaerythritol tetraacrylate and trimethylolpropane triacrylate. The initiator is used to trigger the polymerization reaction of the liquid crystal monomer and the crosslinker. Commonly used thermal initiators include benzoyl peroxide and azobisisobutyronitrile, and photoinitiators include 2-hydroxy-2-methylpropiophenone and benzophenone. The solvent is used to dissolve the liquid crystal monomer and the crosslinker and adjust the viscosity of the reaction system. Commonly used solvents include dimethylformamide, chloroform and tetrahydrofuran.

[0021] (b) immersing the cylindrical core mold in the liquid crystal elastomer solution and then withdrawing it, repeating this process multiple times (the number of times can be adjusted to adjust the wall thickness of the liquid crystal elastomer sleeve), and then allowing the cylindrical core mold to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical core mold evaporates, thereby forming a liquid crystal elastomer sleeve intermediate. The diameter of the cylindrical core mold is 1.3-1.5 times the diameter of the optical fiber. If the diameter of the cylindrical core mold is too small, its inner diameter after stretching will be smaller than the optical fiber and it will not fit over the optical fiber. If the diameter of the cylindrical core mold is too large, its inner diameter after stretching will be much larger than the optical fiber and it will be difficult to secure it after being fit over the optical fiber. The material of the cylindrical core mold is not limited and can be metal, glass, etc., as long as it is not dissolved by the solvent in the liquid crystal elastomer solution and ethanol.

[0022] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate and the cylindrical core mold are separated, and then removing the liquid crystal elastomer sleeve intermediate (without drying);

[0023] (d) First, the liquid crystal elastomer sleeve intermediate is stretched and both ends are fixed, and then ultraviolet light is irradiated to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.5-2 times.

[0024] The preparation process of the liquid crystal elastomer sleeve involves two curing steps. The first curing step occurs in step (b). After the first curing step, the liquid crystal cells in the liquid crystal elastomer sleeve intermediate are randomly arranged. The second curing step occurs in step (d). Before the second curing step, the liquid crystal elastomer sleeve intermediate is stretched. At this time, the liquid crystal cells in the liquid crystal elastomer sleeve intermediate have directionality. When irradiated with ultraviolet light, these liquid crystal cells are fixed to the shape at the time of illumination. However, when irradiated with infrared laser, due to the increase in energy, these liquid crystal cells return to their original randomly arranged state. In other words, the liquid crystal cells in the liquid crystal elastomer sleeve exist in two states: the first is a randomly arranged state, which corresponds to a "shortened" state, and the second is a "aligned" state, which corresponds to a "stretched" state. The switching between these two states is achieved by infrared laser. Normally, the liquid crystal cells are in a stretched state of "aligned arrangement". When irradiated with infrared laser, they absorb energy and transform into a contracted state of "random arrangement". After the illumination stops, they lose energy and return to the stretched state of "aligned arrangement".

[0025] Existing methods are difficult to produce liquid crystal elastomer sleeves with wall thicknesses less than 100μm. Generally, processing such materials requires high-precision mold fabrication technology. Common high-precision mold fabrication techniques include machining and 3D printing. For machining, high-precision CNC machine tools can maintain dimensional tolerances within ±0.01mm-±0.02mm. However, due to assembly accuracy and demolding difficulties, molds produced using machining methods cannot meet the required precision. Another alternative, 3D printing, uses photocurable resin as its primary material. Because the liquid crystal elastomer solution contains organic solvents such as dichloromethane during processing, these solvents are soluble in organic materials like resin and therefore cannot be used as a mold. Furthermore, when the wall thickness of the liquid crystal elastomer sleeve is less than 100μm, demolding becomes extremely difficult using this technology. This invention proposes a novel preparation method that successfully produces liquid crystal elastomer sleeves with wall thicknesses less than 100μm.

[0026] In the negative Poisson's ratio optical actuator as described above, the diameter of the optical fiber is 0.25-2 mm.

[0027] In the negative Poisson's ratio optical actuator as described above, the length of the liquid crystal elastomer sleeve is 8-22 mm.

[0028] As described above, in a negative Poisson's ratio optical actuator, the structural unit of the negative Poisson's ratio frame is in the shape of a double arrow, and the double arrow shape is composed of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, and the two sides of the low V-shape are equal in length. The low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape. Although other negative Poisson's ratio structures are also applicable to the present invention, the negative Poisson's ratio frame with a double arrow-shaped structural unit is the optimal solution after calculation.

[0029] In the negative Poisson's ratio optical actuator as described above, the vertical distance between the tip of the low V-shape and the line connecting the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the line connecting the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the line connecting the two ends of the high V-shape is recorded as the width of the structural unit;

[0030] The negative Poisson's ratio optical actuator is suitable for the heart of a New Zealand white rabbit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4-7, the total number of structural units in the longitudinal direction is 3-6, the width of the structural unit is 2-3.5 mm, the height 1 of the structural unit is 0.6-1.2 mm, the height 2 of the structural unit is 2.5-5 mm, and the wall thickness of the structural unit is 0.1-0.2 mm.

[0031] Alternatively, the negative Poisson's ratio optical actuator is suitable for the heart of a rat, the total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4-6, the total number of structural units in the longitudinal direction is 3-5, the width of the structural unit is 1.5-2.5 mm, the height 1 of the structural unit is 0.5-0.8 mm, the height 2 of the structural unit is 2-3.5 mm, and the wall thickness of the structural unit is 0.1-0.15 mm;

[0032] Alternatively, the negative Poisson's ratio optical actuator is suitable for the heart of a beagle dog, and the total number of structural units in the transverse direction of the negative Poisson's ratio frame is 5-8, the total number of structural units in the longitudinal direction is 4-7, the width of the structural unit is 2.5-4 mm, the height 1 of the structural unit is 0.8-1.5 mm, the height 2 of the structural unit is 3-6 mm, and the wall thickness of the structural unit is 0.15-0.25 mm.

[0033] For the negative Poisson's ratio structure, its transverse and longitudinal contraction ratios are independent of its material but are related to its dimensional parameters. The present invention adjusts the six parameters of the negative Poisson's ratio frame so that when the negative Poisson's ratio optical actuator is applied to the heart, the contraction ratio of the negative Poisson's ratio frame is consistent with the contraction ratio of the heart.

[0034] In the negative Poisson's ratio optical actuator as described above, the negative Poisson's ratio frame is manufactured by a 3D printing method.

[0035] Most conventional materials have a positive Poisson's ratio, meaning that when stretched in one direction, they contract perpendicularly. This mechanical response characteristic cannot meet the special requirements of cardiac contraction. However, the negative Poisson's ratio material employed in the present invention exhibits a unique mechanical response characteristic when stretched in a direction perpendicular to the direction of stretching, rather than contracting. This material's negative Poisson's ratio structure enables the device's lateral and longitudinal changes during contraction to match the direction of cardiac contraction, thereby better fitting the heart and improving device performance and application effectiveness.

[0036] The present invention uses photoactuation as the driving method. On the one hand, light has good penetrability and can achieve remote control of the device without directly contacting the human body, reducing damage to human tissue; on the other hand, photoactuation can achieve fast and precise response and can adjust the device in real time according to actual needs, which is crucial for working in coordination with a dynamically changing organ such as the heart.

[0037] Beneficial effects:

[0038] (1) The present invention uses a material with a negative Poisson's ratio structure to manufacture a photoactuator. Its lateral and longitudinal changes during contraction align with the direction of cardiac contraction, allowing it to better fit the heart. By adjusting the dimensional parameters of the negative Poisson's ratio frame, the photoactuator's contraction ratio when applied to the heart is consistent with that of the heart, effectively resolving the problem of mismatch between the mechanical properties of the device and the heart.

[0039] (2) The present invention adopts a photoactuation method. Light has good penetrability and can remotely control the photoactuator, reducing damage to human tissue. It can also achieve fast and accurate response and meet the needs of working in coordination with the heart.

[0040] (3) The negative Poisson's ratio photoactuator of the present invention is compact in size and can be precisely positioned at the site of cardiac lesions. It only provides mechanical support to the lesion area and does not interfere with the functions of other healthy parts of the heart. It will not have a negative impact on the electrical activity, contraction rhythm or hemodynamics of the healthy myocardium. In addition, the adhesion is reversible and can be safely removed after the lesion recovers, with no long-term effects on the heart. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of contraction and rebound of the negative Poisson's ratio optical actuator of Example 1;

[0042] Figure 2 Schematic diagram of the structural unit of the negative Poisson's ratio frame;

[0043] Figure 3 is the horizontal and vertical shrinkage ratio-time curve of the negative Poisson's ratio frame in Example 3;

[0044] Figure 4is the shrinkage time of liquid crystal elastomer sleeves with different wall thicknesses. DETAILED DESCRIPTION

[0045] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0046] The present invention can use infrared lasers of any wavelength. Since infrared lasers with a wavelength of 808 nm are more common, infrared lasers with a wavelength of 808 nm are used in the following embodiments.

[0047] The following are the test methods for the relevant performance indicators in each embodiment:

[0048] Longitudinal shrinkage ratio of the liquid crystal elastomer sleeve: After placing the liquid crystal elastomer sleeve horizontally, fix one end of it, and pass an infrared laser into the interior of the liquid crystal elastomer sleeve to test the longitudinal shrinkage ratio of the liquid crystal elastomer sleeve. Longitudinal shrinkage ratio = (change in length of the liquid crystal elastomer sleeve along the longitudinal direction / original length of the liquid crystal elastomer sleeve along the longitudinal direction) × 100%.

[0049] Contraction time of the liquid crystal elastomer sleeve: After placing the liquid crystal elastomer sleeve horizontally, fix one end of it, and pass an infrared laser into the interior of the liquid crystal elastomer sleeve to test the change of the longitudinal contraction ratio of the liquid crystal elastomer sleeve over time. The time when the longitudinal contraction ratio reaches 90% of the maximum longitudinal contraction ratio is taken as the contraction time of the liquid crystal elastomer sleeve.

[0050] Longitudinal / lateral shrinkage ratio of the negative Poisson's ratio frame: The assembled negative Poisson's ratio optical actuator was exposed to an infrared laser. After the infrared laser was applied, the liquid crystal elastomer sleeve contracted, driving the entire negative Poisson's ratio frame to contract. The contraction process of the negative Poisson's ratio frame was recorded with a camera. Subsequently, video processing software (such as Jianying and Format Factory) was used to measure the maximum longitudinal length and maximum lateral width of the negative Poisson's ratio frame at different moments, thereby obtaining the time-varying curves of the longitudinal and lateral shrinkage ratios of the negative Poisson's ratio frame. The power of the infrared laser was 6W. The longitudinal shrinkage ratio = (the change in the maximum longitudinal length of the negative Poisson's ratio frame / the initial value of the maximum longitudinal length of the negative Poisson's ratio frame) × 100%, and the lateral shrinkage ratio = (the change in the maximum lateral length of the negative Poisson's ratio frame / the initial value of the maximum lateral length of the negative Poisson's ratio frame) × 100%.

[0051] Example 1

[0052] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0053] (1) Preparation of main materials;

[0054] Cylindrical core mold: diameter 0.35mm;

[0055] Optical fiber: diameter 0.25mm;

[0056] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0057] The negative Poisson's ratio frame was made by 3D printing method, such as Figure 2 As shown, the structural unit of the negative Poisson's ratio frame is a double-arrow shape, which is composed of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the line connecting the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4, the total number of structural units in the longitudinal direction is 3, the width of the structural unit is 3 mm, the height 1 of the structural unit is 1 mm, the height 2 of the structural unit is 4 mm, and the wall thickness of the structural unit is 0.16 mm.

[0058] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0059] (a) Preparing a liquid crystal elastomer solution;

[0060] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0061] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0062] (d) stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.5 times;

[0063] The length of the prepared liquid crystal elastomer sleeve is 12 mm and the wall thickness is 60 μm; Figure 1 As shown, the liquid crystal elastomer sleeve shrinks when exposed to infrared laser light emitted from an optical fiber, and rebounds after the infrared laser light is removed. When the liquid crystal elastomer sleeve is exposed to the infrared laser light for the first time for 100ms, the longitudinal shrinkage ratio is 33%. After the infrared laser light is removed, the longitudinal shrinkage ratio of the liquid crystal elastomer sleeve drops to 0%.

[0064] (3) Preparation of negative Poisson's ratio photoactuators;

[0065] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0066] like Figure 1 As shown, the central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0067] Comparative Example 1-Comparative Example 5

[0068] A liquid crystal elastomer sleeve is basically the same as Example 1, except that the wall thickness of the liquid crystal elastomer sleeve is different. The wall thicknesses of the liquid crystal elastomer sleeves of Comparative Examples 1 to 5 are 100 μm, 200 μm, 300 μm, 400 μm, and 500 μm, respectively.

[0069] The shrinkage time of the liquid crystal elastomer sleeves of Comparative Examples 1 to 5 is as follows: Figure 4 As shown, it can be seen that the wall thickness of the liquid crystal elastomer sleeve must be thin enough, because it must be thin enough to keep up with the beating frequency of the heart.

[0070] Example 2

[0071] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0072] (1) Preparation of main materials;

[0073] Cylindrical core mold: diameter 0.6mm;

[0074] Optical fiber: diameter 0.4mm;

[0075] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0076] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 7, the total number of structural units in the longitudinal direction is 5, the width of the structural unit is 2 mm, the height 1 of the structural unit is 0.6 mm, the height 2 of the structural unit is 2.5 mm, and the wall thickness of the structural unit is 0.1 mm.

[0077] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0078] (a) Preparing a liquid crystal elastomer solution;

[0079] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0080] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0081] (d) stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.6 times;

[0082] The resulting liquid crystal elastomer sleeve had a length of 12.5 mm and a wall thickness of 60 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, its longitudinal contraction ratio was 37%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0083] (3) Preparation of negative Poisson's ratio photoactuators;

[0084] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0085] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0086] Example 3

[0087] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0088] (1) Preparation of main materials;

[0089] Cylindrical core mold: diameter 1.1mm;

[0090] Optical fiber: diameter 0.8mm;

[0091] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0092] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4, the total number of structural units in the longitudinal direction is 3, the width of the structural unit is 3.5 mm, the height 1 of the structural unit is 1.2 mm, the height 2 of the structural unit is 5 mm, and the wall thickness of the structural unit is 0.2 mm.

[0093] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0094] (a) Preparing a liquid crystal elastomer solution;

[0095] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0096] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0097] (d) first stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.8 times;

[0098] The prepared liquid crystal elastomer sleeve had a length of 15 mm and a wall thickness of 75 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, the longitudinal contraction ratio was 44%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0099] (3) Preparation of negative Poisson's ratio photoactuators;

[0100] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0101] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0102] When the liquid crystal elastomer sleeve of the negative Poisson's ratio optical actuator is irradiated by infrared laser, the longitudinal / lateral contraction ratio-time curve of the negative Poisson's ratio frame is as follows: Figure 3 shown.

[0103] Example 4

[0104] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0105] (1) Preparation of main materials;

[0106] Cylindrical core mold: diameter 1.6mm;

[0107] Optical fiber: diameter 1.2mm;

[0108] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0109] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 6, the total number of structural units in the longitudinal direction is 6, the width of the structural unit is 3 mm, the height 1 of the structural unit is 0.8 mm, the height 2 of the structural unit is 3 mm, and the wall thickness of the structural unit is 0.13 mm.

[0110] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0111] (a) Preparing a liquid crystal elastomer solution;

[0112] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0113] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0114] (d) first stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 2 times;

[0115] The prepared liquid crystal elastomer sleeve had a length of 18 mm and a wall thickness of 90 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, its longitudinal contraction ratio was 50%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0116] (3) Preparation of negative Poisson's ratio photoactuators;

[0117] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0118] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0119] Example 5

[0120] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0121] (1) Preparation of main materials;

[0122] Cylindrical core mold: diameter 0.4mm;

[0123] Optical fiber: diameter 0.3mm;

[0124] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0125] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4, the total number of structural units in the longitudinal direction is 4, the width of the structural unit is 2 mm, the height 1 of the structural unit is 0.5 mm, the height 2 of the structural unit is 2 mm, and the wall thickness of the structural unit is 0.1 mm.

[0126] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0127] (a) Preparing a liquid crystal elastomer solution;

[0128] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0129] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0130] (d) stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.5 times;

[0131] The prepared liquid crystal elastomer sleeve had a length of 8 mm and a wall thickness of 60 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, its longitudinal contraction ratio was 33%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0132] (3) Preparation of negative Poisson's ratio photoactuators;

[0133] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0134] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0135] Example 6

[0136] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0137] (1) Preparation of main materials;

[0138] Cylindrical core mold: diameter 0.9mm;

[0139] Optical fiber: diameter 0.6mm;

[0140] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0141] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 6, the total number of structural units in the longitudinal direction is 5, the width of the structural unit is 1.5 mm, the height 1 of the structural unit is 0.5 mm, the height 2 of the structural unit is 2 mm, and the wall thickness of the structural unit is 0.1 mm.

[0142] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0143] (a) Preparing a liquid crystal elastomer solution;

[0144] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0145] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0146] (d) stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.6 times;

[0147] The prepared liquid crystal elastomer sleeve had a length of 10 mm and a wall thickness of 70 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, the longitudinal contraction ratio was 37%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0148] (3) Preparation of negative Poisson's ratio photoactuators;

[0149] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0150] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0151] Example 7

[0152] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0153] (1) Preparation of main materials;

[0154] Cylindrical core mold: diameter 1.3mm;

[0155] Optical fiber: diameter 1mm;

[0156] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0157] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4, the total number of structural units in the longitudinal direction is 3, the width of the structural unit is 2.5 mm, the height 1 of the structural unit is 0.8 mm, the height 2 of the structural unit is 3.5 mm, and the wall thickness of the structural unit is 0.15 mm.

[0158] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0159] (a) Preparing a liquid crystal elastomer solution;

[0160] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0161] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0162] (d) first stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.8 times;

[0163] The resulting liquid crystal elastomer sleeve had a length of 10.5 mm and a wall thickness of 75 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, its longitudinal contraction ratio was 44%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0164] (3) Preparation of negative Poisson's ratio photoactuators;

[0165] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0166] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0167] Example 8

[0168] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0169] (1) Preparation of main materials;

[0170] Cylindrical core mold: diameter 2.2mm;

[0171] Optical fiber: diameter 1.6mm;

[0172] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0173] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 6, the total number of structural units in the longitudinal direction is 4, the width of the structural unit is 2 mm, the height 1 of the structural unit is 0.8 mm, the height 2 of the structural unit is 3 mm, and the wall thickness of the structural unit is 0.13 mm.

[0174] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0175] (a) Preparing a liquid crystal elastomer solution;

[0176] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0177] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0178] (d) first stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 2 times;

[0179] The prepared liquid crystal elastomer sleeve had a length of 12 mm and a wall thickness of 80 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, its longitudinal contraction ratio was 50%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0180] (3) Preparation of negative Poisson's ratio photoactuators;

[0181] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0182] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0183] Example 9

[0184] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0185] (1) Preparation of main materials;

[0186] Cylindrical core mold: diameter 1.2mm;

[0187] Optical fiber: diameter 0.8mm;

[0188] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0189] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 5, the total number of structural units in the longitudinal direction is 5, the width of the structural unit is 3 mm, the height 1 of the structural unit is 0.8 mm, the height 2 of the structural unit is 3 mm, and the wall thickness of the structural unit is 0.15 mm.

[0190] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0191] (a) Preparing a liquid crystal elastomer solution;

[0192] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0193] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0194] (d) stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.5 times;

[0195] The prepared liquid crystal elastomer sleeve had a length of 15 mm and a wall thickness of 70 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, the longitudinal contraction ratio was 33%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0196] (3) Preparation of negative Poisson's ratio photoactuators;

[0197] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0198] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0199] Example 10

[0200] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0201] (1) Preparation of main materials;

[0202] Cylindrical core mold: diameter 1.7mm;

[0203] Optical fiber: diameter 1.2mm;

[0204] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0205] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 6, the total number of structural units in the longitudinal direction is 5, the width of the structural unit is 3.6 mm, the height 1 of the structural unit is 1.1 mm, the height 2 of the structural unit is 4.4 mm, and the wall thickness of the structural unit is 0.2 mm.

[0206] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0207] (a) Preparing a liquid crystal elastomer solution;

[0208] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0209] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0210] (d) stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.6 times;

[0211] The resulting liquid crystal elastomer sleeve had a length of 22 mm and a wall thickness of 95 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, its longitudinal contraction ratio was 37%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0212] (3) Preparation of negative Poisson's ratio photoactuators;

[0213] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0214] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0215] Example 11

[0216] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0217] (1) Preparation of main materials;

[0218] Cylindrical core mold: diameter 2.3mm;

[0219] Optical fiber: diameter 1.6mm;

[0220] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0221] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 5, the total number of structural units in the longitudinal direction is 4, the width of the structural unit is 4 mm, the height 1 of the structural unit is 1.5 mm, the height 2 of the structural unit is 5 mm, and the wall thickness of the structural unit is 0.25 mm.

[0222] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0223] (a) Preparing a liquid crystal elastomer solution;

[0224] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0225] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0226] (d) first stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.8 times;

[0227] The prepared liquid crystal elastomer sleeve had a length of 20 mm and a wall thickness of 90 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, the longitudinal contraction ratio was 44%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0228] (3) Preparation of negative Poisson's ratio photoactuators;

[0229] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0230] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

[0231] Example 12

[0232] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0233] (1) Preparation of main materials;

[0234] Cylindrical core mold: diameter 3mm;

[0235] Optical fiber: diameter 2mm;

[0236] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0237] The negative Poisson's ratio frame was made by a 3D printing method. The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, the two sides of the low V-shape are equal in length, the low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape; the vertical distance between the tip of the low V-shape and the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connection between the two ends of the high V-shape is recorded as the width of the structural unit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 7, the total number of structural units in the longitudinal direction is 7, the width of the structural unit is 2.5 mm, the height 1 of the structural unit is 0.8 mm, the height 2 of the structural unit is 3 mm, and the wall thickness of the structural unit is 0.15 mm.

[0238] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0239] (a) Preparing a liquid crystal elastomer solution;

[0240] (b) immersing the cylindrical mandrel in the liquid crystal elastomer solution and then removing it, repeating this process multiple times, and then allowing the mandrel to stand until the solvent in the liquid crystal elastomer solution adhering to the surface of the cylindrical mandrel evaporates, thereby forming a liquid crystal elastomer sleeve intermediate;

[0241] (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate;

[0242] (d) first stretching the liquid crystal elastomer sleeve intermediate and fixing both ends thereof, and then irradiating the sleeve with ultraviolet light to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 2 times;

[0243] The prepared liquid crystal elastomer sleeve had a length of 21 mm and a wall thickness of 95 μm. When the liquid crystal elastomer sleeve was first irradiated with infrared laser light for 100 milliseconds, its longitudinal contraction ratio was 50%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0244] (3) Preparation of negative Poisson's ratio photoactuators;

[0245] The negative Poisson's ratio frame, the liquid crystal elastomer sleeve and the optical fiber are assembled to obtain a negative Poisson's ratio optical actuator;

[0246] The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; the liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame; the central axis of the liquid crystal elastomer sleeve is collinear with the output optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber.

Claims

1. A negative Poisson's ratio optical actuator, characterized in that: It includes a negative Poisson's ratio frame, a liquid crystal elastomer sleeve, and an optical fiber; The wall thickness of the liquid crystal elastomer sleeve is less than 100 μm; The central axis of the liquid crystal elastomer sleeve is parallel to the longitudinal direction of the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is fixedly connected to the negative Poisson's ratio frame; The central axis of the liquid crystal elastomer sleeve is collinear with the optical axis of the optical fiber, and the rear end of the liquid crystal elastomer sleeve is sleeved on the front end of the optical fiber; The liquid crystal elastomer sleeve shrinks when irradiated by infrared laser emitted from the optical fiber, and rebounds after the infrared laser irradiation is removed.

2. The negative Poisson's ratio optical actuator according to claim 1, characterized in that: The liquid crystal elastomer sleeve is located inside the negative Poisson's ratio frame, and the liquid crystal elastomer sleeve is located in the middle of the negative Poisson's ratio frame.

3. The negative Poisson's ratio optical actuator according to claim 2, characterized in that: The front and rear ends of the liquid crystal elastomer sleeve coincide with the edges of the negative Poisson's ratio frame, or extend from the negative Poisson's ratio frame.

4. The negative Poisson's ratio optical actuator according to claim 1, wherein: The steps for preparing the liquid crystal elastomer sleeve are as follows: (a) Preparing a liquid crystal elastomer solution; (b) immersing the cylindrical core mold in a liquid crystal elastomer solution and removing it, repeating this process multiple times, and allowing the cylindrical core mold to stand until the solvent in the liquid crystal elastomer solution attached to the surface of the cylindrical core mold evaporates, thereby forming a liquid crystal elastomer sleeve intermediate, wherein the diameter of the cylindrical core mold is 1.3-1.5 times the diameter of the optical fiber; (c) immersing the liquid crystal elastomer sleeve intermediate and the cylindrical core mold in an ethanol-water solution or ethanol while simultaneously subjecting the intermediate to ultrasonic vibration until the liquid crystal elastomer sleeve intermediate is separated from the cylindrical core mold, and then removing the liquid crystal elastomer sleeve intermediate; (d) First, the liquid crystal elastomer sleeve intermediate is stretched and both ends are fixed, and then ultraviolet light is irradiated to obtain the liquid crystal elastomer sleeve, wherein the stretching ratio is 1.5-2 times.

5. The negative Poisson's ratio optical actuator according to claim 4, characterized in that: The diameter of the optical fiber is 0.25-2 mm.

6. The negative Poisson's ratio optical actuator according to claim 1, characterized in that: The length of the liquid crystal elastomer sleeve is 8-22mm.

7. The negative Poisson's ratio optical actuator according to claim 1, wherein: The structural unit of the negative Poisson's ratio frame is a double-arrow shape, which consists of a high V-shape and a low V-shape. The two sides of the high V-shape are equal in length, and the two sides of the low V-shape are equal in length. The low V-shape is located inside the high V-shape, and the two ends of the low V-shape are respectively connected to the two ends of the high V-shape.

8. The negative Poisson's ratio optical actuator according to claim 7, characterized in that: The vertical distance between the tip of the low V-shape and the connecting line of the two ends of the low V-shape is recorded as the height 1 of the structural unit, the vertical distance between the tip of the high V-shape and the connecting line of the two ends of the high V-shape is recorded as the height 2 of the structural unit, and the length of the connecting line of the two ends of the high V-shape is recorded as the width of the structural unit; The negative Poisson's ratio optical actuator is suitable for the heart of a New Zealand white rabbit. The total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4-7, the total number of structural units in the longitudinal direction is 3-6, the width of the structural unit is 2-3.5 mm, the height 1 of the structural unit is 0.6-1.2 mm, the height 2 of the structural unit is 2.5-5 mm, and the wall thickness of the structural unit is 0.1-0.2 mm. Alternatively, the negative Poisson's ratio optical actuator is suitable for the heart of a rat, the total number of structural units in the transverse direction of the negative Poisson's ratio frame is 4-6, the total number of structural units in the longitudinal direction is 3-5, the width of the structural unit is 1.5-2.5 mm, the height 1 of the structural unit is 0.5-0.8 mm, the height 2 of the structural unit is 2-3.5 mm, and the wall thickness of the structural unit is 0.1-0.15 mm; Alternatively, the negative Poisson's ratio optical actuator is suitable for the heart of a beagle dog, and the total number of structural units in the transverse direction of the negative Poisson's ratio frame is 5-8, the total number of structural units in the longitudinal direction is 4-7, the width of the structural unit is 2.5-4 mm, the height 1 of the structural unit is 0.8-1.5 mm, the height 2 of the structural unit is 3-6 mm, and the wall thickness of the structural unit is 0.15-0.25 mm.

9. The negative Poisson's ratio optical actuator according to claim 1, wherein: The negative Poisson's ratio frame was made using a 3D printing method.

Images