A left ventricular assist device with an electrocardiogram-optical control switch

Abstract

The present invention belongs to the technical field of medical devices and relates to a left ventricular assist device with an electrocardiogram-light-controlled switch, comprising an electrocardiogram device, an infrared laser, a negative Poisson's ratio optical actuator, and a programmable logic controller (PLC). The negative Poisson's ratio optical actuator comprises a negative Poisson's ratio frame, a liquid crystal elastomer sleeve, and an optical fiber; the electrocardiogram device and the infrared laser are simultaneously connected to the PLC, which obtains the current electrocardiogram of the monitored subject in real time through the electrocardiogram device. Each time a new set of points P, Q, R, S, and T is obtained, the infrared laser is controlled to start after a delay of t1 corresponding to the time of the set of points S, and to continue starting for a time of t2. The present invention prepares a specific optical actuator and applies it to a left ventricular assist device, solving the problems of mechanical property mismatch of traditional heart-related devices, limited driving methods, easy blood contact complications, impact on other heart functions, and lack of personalization.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices and relates to a left ventricular assist device with an electrocardiogram-light-controlled switch. Background Art

[0002] Left ventricular assist devices (LVADs) are of great significance in the treatment of advanced heart failure, significantly improving patients' quality of life and survival rates. However, most existing commercial LVADs use a blood pump design, which directly replaces the left ventricle's pumping function rather than assisting its contraction. For example, Abbott's Heartmate 3 and Impella percutaneous heart pumps require the installation of an outflow tract in the heart's aorta, and patients need to wear these devices externally for a long time. This design not only increases the burden on patients, but may also cause a series of complications such as thrombosis and infection due to direct contact between blood and the device.

[0003] Both the literature (Soft robotic sleeve supports heart function[J].ScienceTranslational Medicine, 2017.) and (Cardioprotective effect of silicon-builtrestraint device (ASD) for left ventricular remodeling in rat heart failuremodel[J].Journal of Materials Science: Materials in Medicine, 2022, 33(5):42.) provide sleeve-type left ventricular assist devices, which put a sleeve on the outside of the heart and use air or water pressure to squeeze the heart to contract and pump blood. Although this type of device can assist the left ventricle in contraction to a certain extent, its disadvantage is that the sleeve design may affect the healthy right ventricular function, leading to an imbalance in the overall heart function. At the same time, the sleeve-type assist device is large in size and lacks personalized services, making it difficult to meet the specific needs of different patients.

[0004] In summary, existing left ventricular assist devices still have many problems, such as blood contact complications, impact on other cardiac functions, and lack of personalized treatment. These problems not only limit the widespread application of left ventricular assist devices, but also affect the treatment effect and quality of life of patients. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art and provide a left ventricular assist device with an electrocardiogram-light-controlled switch.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A left ventricular assist device with an electrocardiogram-light-controlled switch, comprising an electrocardiogram device, an infrared laser, a negative Poisson's ratio optical actuator, and a PLC;

[0008] The negative Poisson's ratio optical actuator includes a negative Poisson's ratio frame, a liquid crystal elastomer sleeve and an optical fiber;

[0009] The wall thickness of the liquid crystal elastomer sleeve is less than 100 μm;

[0010] 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;

[0011] 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;

[0012] 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;

[0013] An infrared laser is used to emit laser light toward the rear end of an optical fiber in the negative Poisson's ratio optical actuator;

[0014] The ECG device and infrared laser are connected to the PLC at the same time. The PLC obtains the current ECG of the monitored object in real time through the ECG device. Every time a new set of P points, Q points, R points, S points, and T points is obtained, the infrared laser is controlled to start after the time corresponding to the set of S points with a delay of t1 and continue to start for t2 time.

[0015] Point P is the starting point of the atrial contraction phase of the monitored subject, point Q is the mid-point of the atrial contraction phase of the monitored subject, point R is the end point of the atrial contraction phase of the monitored subject and the starting point of the ventricular contraction phase of the monitored subject, point S is the mid-point of the ventricular contraction phase of the monitored subject, and point T is the end point of the ventricular contraction phase of the monitored subject;

[0016] The process of obtaining t1 is as follows: obtain the historical electrocardiogram of the monitored object, obtain the time intervals between all adjacent S points and Q points in the historical electrocardiogram, and calculate the average value to obtain t1;

[0017] The process of obtaining t2 is as follows: obtain the historical electrocardiogram of the monitored object, obtain the time intervals between all adjacent T points and R points in the historical electrocardiogram, and calculate the average value to obtain t2;

[0018] The number of heartbeats in the historical electrocardiogram is more than 200, and the test duration is 100-200s.

[0019] The present invention can solve the problems of blood contact complications, impact on other heart functions and lack of personalization. The specific analysis is as follows:

[0020] Avoiding complications from blood contact: The device's in vitro design ensures only the negative Poisson's ratio photoactuator comes into contact with the heart, while all other components are located outside the body, significantly reducing the risk of infection and thrombosis. Non-invasive contact prevents the photoactuator from entering the heart chambers or coming into contact with blood, thus avoiding potential complications from direct contact with blood, such as thrombosis, hemolysis, and immune rejection. Biocompatible materials further reduce the risk of tissue inflammation or rejection, further reducing the risk of tissue inflammation or rejection.

[0021] Does not affect other heart functions: Precise positioning: The negative Poisson's ratio photoactuator is small in size and can be precisely bonded to the diseased part of the heart, providing mechanical support only to the diseased area without interfering with the functions of other healthy parts of the heart; Local assistance: The design of the device focuses on assisting the functional recovery of the diseased part and will not have a negative impact on the electrical activity, contraction rhythm or hemodynamics of healthy myocardium; Reversible support: The bonding of the photoactuator is reversible and can be safely removed after the diseased part recovers, without causing long-term effects on the heart.

[0022] Personalization: The left ventricular assist device has a highly personalized design and can be customized according to the patient's specific situation. Design the size of the photoactuator according to the size of the heart lesion: The device accurately measures the size of the patient's left ventricular lesion and designs a negative Poisson's ratio photoactuator that matches it. The negative Poisson's ratio structure has unique mechanical properties and can expand laterally when subjected to force, thereby better adapting to the morphological changes of the heart. This design ensures that the photoactuator can fit closely to the area of heart lesions, providing precise mechanical support while reducing damage to surrounding healthy tissue. Design the contraction frequency of the photoactuator according to the individual electrocardiogram: The device analyzes the patient's electrocardiogram signal and adjusts the contraction frequency of the photoactuator in real time to synchronize it with the natural rhythm of the patient's heart. This synchronized design not only improves the heart's pumping efficiency, but also avoids hemodynamic disorders caused by frequency mismatch, truly realizing personalized treatment.

[0023] As the preferred technical solution:

[0024] In the left ventricular assist device with an ECG-light-controlled switch as described above, the ECG device is a Bluetooth ECG device.

[0025] In the left ventricular assist device with an electrocardiogram-light-controlled switch 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.

[0026] In the left ventricular assist device with an electrocardiogram-light-controlled switch 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.

[0027] The steps for preparing the liquid crystal elastomer sleeve of the left ventricular assist device with an electrocardiogram-light-controlled switch are as follows:

[0028] (a) Preparing a liquid crystal elastomer solution;

[0029] (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;

[0030] (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;

[0031] (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.

[0032] In the left ventricular assist device with an electrocardiographic-optically controlled switch as described above, the diameter of the optical fiber is 0.25-2 mm.

[0033] In the left ventricular assist device with an electrocardiogram-light-controlled switch as described above, the length of the liquid crystal elastomer sleeve is 8-22 cm.

[0034] As described above, in a left ventricular assist device with an electrocardiogram-light-controlled switch, 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, 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.

[0035] In the left ventricular assist device with an electrocardiogram-light-controlled switch, 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.

[0036] 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.

[0037] 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;

[0038] 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.

[0039] Beneficial effects:

[0040] (1) In the left ventricular assist device of the present invention, only the negative Poisson's ratio photoactuator is in contact with the heart, and the remaining components are located outside the body. The photoactuator is only bonded to the outer surface of the heart and does not contact the blood. At the same time, the use of highly biocompatible materials greatly reduces the risk of blood contact complications such as infection and thrombosis.

[0041] (2) The left ventricular assist device of the present invention is highly personalized. The size of the photoactuator can be designed according to the size of the patient's heart disease site, so that it fits closely to the diseased area and reduces damage to surrounding healthy tissues. The photoactuator contraction frequency can also be adjusted in real time according to the individual electrocardiogram, synchronized with the patient's natural heart rhythm, thereby improving the heart's pumping efficiency, avoiding hemodynamic disorders, and truly realizing personalized treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of contraction and rebound of the negative Poisson's ratio optical actuator of Example A1;

[0043] Figure 2 Schematic diagram of the structural unit of the negative Poisson's ratio frame;

[0044] Figure 3 is the transverse and longitudinal shrinkage ratio-time curve of the negative Poisson's ratio frame in Example A3;

[0045] Figure 4 is the shrinkage time of liquid crystal elastomer sleeves with different wall thicknesses;

[0046] Figure 5 Diagram for the ECG-Program-Light Actuator. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] The following are the test methods for the relevant performance indicators in each embodiment:

[0050] 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%.

[0051] 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.

[0052] 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%.

[0053] Example A1

[0054] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0055] (1) Preparation of main materials;

[0056] Cylindrical core mold: diameter 0.35mm;

[0057] Optical fiber: diameter 0.25mm;

[0058] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0059] 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.

[0060] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0061] (a) Preparing a liquid crystal elastomer solution;

[0062] (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;

[0063] (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;

[0064] (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;

[0065] The length of the prepared liquid crystal elastomer sleeve is 12 cm 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%.

[0066] (3) Preparation of negative Poisson's ratio photoactuators;

[0067] 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;

[0068] 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.

[0069] Comparative Example 1-Comparative Example 5

[0070] A liquid crystal elastomer sleeve is basically the same as Example A1, except that the wall thickness of the liquid crystal elastomer sleeve is different. The wall thicknesses of the liquid crystal elastomer sleeves in Comparative Examples 1 to 5 are 100 μm, 200 μm, 300 μm, 400 μm, and 500 μm, respectively.

[0071] 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.

[0072] Example A2

[0073] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0074] (1) Preparation of main materials;

[0075] Cylindrical core mold: diameter 0.6mm;

[0076] Optical fiber: diameter 0.4mm;

[0077] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0078] 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.

[0079] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0080] (a) Preparing a liquid crystal elastomer solution;

[0081] (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;

[0082] (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;

[0083] (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;

[0084] The resulting liquid crystal elastomer sleeve had a length of 12.5 cm 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%.

[0085] (3) Preparation of negative Poisson's ratio photoactuators;

[0086] 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;

[0087] 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.

[0088] Example A3

[0089] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0090] (1) Preparation of main materials;

[0091] Cylindrical core mold: diameter 1.1mm;

[0092] Optical fiber: diameter 0.8mm;

[0093] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0094] 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.

[0095] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0096] (a) Preparing a liquid crystal elastomer solution;

[0097] (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;

[0098] (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;

[0099] (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;

[0100] The resulting liquid crystal elastomer sleeve had a length of 15 cm 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%.

[0101] (3) Preparation of negative Poisson's ratio photoactuators;

[0102] 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;

[0103] 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.

[0104] 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.

[0105] Example A4

[0106] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0107] (1) Preparation of main materials;

[0108] Cylindrical core mold: diameter 1.6mm;

[0109] Optical fiber: diameter 1.2mm;

[0110] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0111] 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.

[0112] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0113] (a) Preparing a liquid crystal elastomer solution;

[0114] (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;

[0115] (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;

[0116] (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;

[0117] The resulting liquid crystal elastomer sleeve had a length of 18 cm 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%.

[0118] (3) Preparation of negative Poisson's ratio photoactuators;

[0119] 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;

[0120] 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.

[0121] Example A5

[0122] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0123] (1) Preparation of main materials;

[0124] Cylindrical core mold: diameter 0.4mm;

[0125] Optical fiber: diameter 0.3mm;

[0126] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0127] 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.

[0128] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0129] (a) Preparing a liquid crystal elastomer solution;

[0130] (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;

[0131] (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;

[0132] (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;

[0133] The resulting liquid crystal elastomer sleeve had a length of 8 cm 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%.

[0134] (3) Preparation of negative Poisson's ratio photoactuators;

[0135] 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;

[0136] 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.

[0137] Example A6

[0138] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0139] (1) Preparation of main materials;

[0140] Cylindrical core mold: diameter 0.9mm;

[0141] Optical fiber: diameter 0.6mm;

[0142] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0143] 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.

[0144] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0145] (a) Preparing a liquid crystal elastomer solution;

[0146] (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;

[0147] (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;

[0148] (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;

[0149] The prepared liquid crystal elastomer sleeve had a length of 10 cm and a wall thickness of 70 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%.

[0150] (3) Preparation of negative Poisson's ratio photoactuators;

[0151] 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;

[0152] 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.

[0153] Example A7

[0154] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0155] (1) Preparation of main materials;

[0156] Cylindrical core mold: diameter 1.3mm;

[0157] Optical fiber: diameter 1mm;

[0158] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0159] 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.

[0160] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0161] (a) Preparing a liquid crystal elastomer solution;

[0162] (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;

[0163] (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;

[0164] (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;

[0165] The resulting liquid crystal elastomer sleeve had a length of 10.5 cm 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%.

[0166] (3) Preparation of negative Poisson's ratio photoactuators;

[0167] 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;

[0168] 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.

[0169] Example A8

[0170] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0171] (1) Preparation of main materials;

[0172] Cylindrical core mold: diameter 2.2mm;

[0173] Optical fiber: diameter 1.6mm;

[0174] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0175] 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.

[0176] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0177] (a) Preparing a liquid crystal elastomer solution;

[0178] (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;

[0179] (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;

[0180] (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;

[0181] The prepared liquid crystal elastomer sleeve had a length of 12 cm 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%.

[0182] (3) Preparation of negative Poisson's ratio photoactuators;

[0183] 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;

[0184] 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.

[0185] Example A9

[0186] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0187] (1) Preparation of main materials;

[0188] Cylindrical core mold: diameter 1.2mm;

[0189] Optical fiber: diameter 0.8mm;

[0190] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0191] 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.

[0192] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0193] (a) Preparing a liquid crystal elastomer solution;

[0194] (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;

[0195] (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;

[0196] (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;

[0197] The resulting liquid crystal elastomer sleeve had a length of 15 cm and a wall thickness of 70 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%.

[0198] (3) Preparation of negative Poisson's ratio photoactuators;

[0199] 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;

[0200] 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.

[0201] Example A10

[0202] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0203] (1) Preparation of main materials;

[0204] Cylindrical core mold: diameter 1.7mm;

[0205] Optical fiber: diameter 1.2mm;

[0206] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0207] 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.

[0208] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0209] (a) Preparing a liquid crystal elastomer solution;

[0210] (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;

[0211] (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;

[0212] (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;

[0213] The resulting liquid crystal elastomer sleeve had a length of 22 cm 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%.

[0214] (3) Preparation of negative Poisson's ratio photoactuators;

[0215] 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;

[0216] 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.

[0217] Example A11

[0218] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0219] (1) Preparation of main materials;

[0220] Cylindrical core mold: diameter 2.3mm;

[0221] Optical fiber: diameter 1.6mm;

[0222] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0223] 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.

[0224] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0225] (a) Preparing a liquid crystal elastomer solution;

[0226] (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;

[0227] (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;

[0228] (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;

[0229] The resulting liquid crystal elastomer sleeve had a length of 20 cm 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 44%. After the infrared laser light was removed, the longitudinal contraction ratio of the liquid crystal elastomer sleeve dropped to 0%.

[0230] (3) Preparation of negative Poisson's ratio photoactuators;

[0231] 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;

[0232] 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.

[0233] Example A12

[0234] A method for preparing a negative Poisson's ratio optical actuator, comprising the following steps:

[0235] (1) Preparation of main materials;

[0236] Cylindrical core mold: diameter 3mm;

[0237] Optical fiber: diameter 2mm;

[0238] (2) Prepare negative Poisson's ratio frame and liquid crystal elastomer sleeve respectively;

[0239] 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.

[0240] The preparation process of the liquid crystal elastomer sleeve is as follows:

[0241] (a) Preparing a liquid crystal elastomer solution;

[0242] (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;

[0243] (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;

[0244] (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;

[0245] The resulting liquid crystal elastomer sleeve had a length of 21 cm 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%.

[0246] (3) Preparation of negative Poisson's ratio photoactuators;

[0247] 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;

[0248] 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.

[0249] A left ventricular assist device with an electrocardiogram-light-controlled switch, comprising a Bluetooth electrocardiogram device, an infrared laser, a negative Poisson's ratio optical actuator, and a PLC; the negative Poisson's ratio optical actuator is any one of the negative Poisson's ratio optical actuators prepared in Examples A1 to A12; the infrared laser is used to emit laser light toward the rear end of an optical fiber in the negative Poisson's ratio optical actuator;

[0250] The Bluetooth ECG device and infrared laser are connected to the PLC at the same time. The PLC obtains the current ECG of the monitored object in real time through the Bluetooth ECG device. Every time a new set of P points, Q points, R points, S points, and T points is obtained, the infrared laser is controlled to start after the time corresponding to the set of S points with a delay of t1 and continue to start for t2 time.

[0251] like Figure 5 As shown, point P is the starting point of the atrial contraction phase of the monitored object, point Q is the mid-point of the atrial contraction phase of the monitored object, point R is the end point of the atrial contraction phase of the monitored object and the starting point of the ventricular contraction phase of the monitored object, point S is the mid-point of the ventricular contraction phase of the monitored object, and point T is the end point of the ventricular contraction phase of the monitored object;

[0252] The process of obtaining t1 is as follows: obtain the historical electrocardiogram of the monitored object, obtain the time intervals between all adjacent S points and Q points in the historical electrocardiogram, and calculate the average value to obtain t1;

[0253] The process of obtaining t2 is as follows: obtain the historical electrocardiogram of the monitored object, obtain the time intervals between all adjacent T points and R points in the historical electrocardiogram, and calculate the average value to obtain t2;

[0254] The number of heartbeats in the historical electrocardiogram is more than 200, and the test duration is 100-200s.

[0255] Example B1

[0256] A left ventricular assist therapy method based on an ECG-light-controlled switch, using the left ventricular assist device with the ECG-light-controlled switch described above, wherein the negative Poisson's ratio photoactuator in the device is the negative Poisson's ratio photoactuator prepared in Example A1, and the specific steps are as follows:

[0257] (1) Select the animal to be treated;

[0258] Animals were New Zealand white rabbits. Related information: New Zealand white rabbits were selected at 2-3 months of age and weighed 2±0.5 kg. The infarction model was a transmural left ventricular myocardial infarction, with the infarction size being a circle with a diameter of 8-10 mm. After the infarction, the LVEDV (left ventricular end-diastolic volume) decreased to 6-7 mL, the LVESV (left ventricular end-diastolic volume) decreased to 2-3 mL, the EF (left ventricular ejection fraction) decreased to 40-45%, and the FS (left ventricular fractional shortening) decreased to 20-25%.

[0259] (2) Obtain t1 and t2;

[0260] Obtain an electrocardiogram (ECG) of the animal requiring treatment (with at least 200 heartbeats and a test duration of 100-200 seconds). Obtain the time intervals between all adjacent S and Q points in the ECG and average them to obtain t1. Obtain the time intervals between all adjacent T and R points in the ECG and average them to obtain t2.

[0261] (3) Assisting the animal's left ventricle;

[0262] The negative Poisson's ratio photoactuator is glued to the left ventricle of the animal using biological glue, and the central axis of the liquid crystal elastomer sleeve in the negative Poisson's ratio photoactuator is kept parallel to the long axis of the animal's heart. At this time, a Bluetooth electrocardiogram device is activated to obtain an electrocardiogram of the animal;

[0263] The laser light frequency (4 Hz), delay time t1, and continuous start time t2 are set in the PLC program. The PLC controls the opening and closing of the laser. After the laser is turned on, the liquid crystal elastomer sleeve in the negative Poisson's ratio optical actuator contracts longitudinally, driving the negative Poisson's ratio frame to contract synchronously. After the laser is turned off, the liquid crystal elastomer sleeve returns to its original state, driving the negative Poisson's ratio frame to return to its original state synchronously. This process is repeated to synchronously assist the contraction and relaxation of the left ventricle.

[0264] By taking a video of a negative Poisson's ratio photoactuator beating on the heart with a high-speed camera, it was calculated that the longitudinal contraction of the negative Poisson's ratio photoactuator can reach 35-50%, far reaching the contraction ratio of the left ventricle of a normal heart (20-30%). Therefore, the negative Poisson's ratio photoactuator can effectively assist the contraction of the left ventricle; by taking a video of a negative Poisson's ratio photoactuator beating on the heart with a high-speed camera, it was calculated that the longitudinal contraction of the negative Poisson's ratio photoactuator can achieve the same frequency as the heart, with an error of less than 5ms; monitoring by a small animal ultrasound scanner showed that after treatment with a left ventricular assist device, the animals' LVEDV decreased by 60-80%, LVESV decreased by 70-90%, EF increased by 40-50%, and FS increased by 50-60%.

[0265] Example B2

[0266] A left ventricular assist therapy method based on an ECG-light-controlled switch, using the left ventricular assist device with the ECG-light-controlled switch described above, wherein the negative Poisson's ratio photoactuator in the device is the negative Poisson's ratio photoactuator prepared in Example A5, is performed in the following steps:

[0267] (1) Select the animal to be treated;

[0268] The animals used were Sprague-Dawley rats. Related information: Sprague-Dawley rats were 6-9 weeks old and weighed 200 ± 50 g. The infarction model was a transmural left ventricular myocardial infarction, with the infarct size being a circle with a diameter of 5-6 mm. After myocardial infarction, the LVEDV decreased to 1-1.2 mL, the LVESV decreased to 0.4-0.7 mL, the EF decreased to 35-40%, and the FS decreased to 13-20%.

[0269] (2) Obtain t1 and t2;

[0270] Obtain an electrocardiogram (ECG) of the animal requiring treatment (with at least 200 heartbeats and a test duration of 100-200 seconds). Obtain the time intervals between all adjacent S and Q points in the ECG and average them to obtain t1. Obtain the time intervals between all adjacent T and R points in the ECG and average them to obtain t2.

[0271] (3) Assisting the animal's left ventricle;

[0272] The negative Poisson's ratio photoactuator is glued to the left ventricle of the animal using biological glue, and the central axis of the liquid crystal elastomer sleeve in the negative Poisson's ratio photoactuator is kept parallel to the long axis of the animal's heart. At this time, a Bluetooth electrocardiogram device is activated to obtain an electrocardiogram of the animal;

[0273] The laser light frequency (4 Hz), delay time t1, and continuous start time t2 are set in the PLC program. The PLC controls the opening and closing of the laser. After the laser is turned on, the liquid crystal elastomer sleeve in the negative Poisson's ratio optical actuator contracts longitudinally, driving the negative Poisson's ratio frame to contract synchronously. After the laser is turned off, the liquid crystal elastomer sleeve returns to its original state, driving the negative Poisson's ratio frame to return to its original state synchronously. This process is repeated to synchronously assist the contraction and relaxation of the left ventricle.

[0274] By taking a video of a negative Poisson's ratio photoactuator beating on the heart with a high-speed camera, it was calculated that the longitudinal contraction of the negative Poisson's ratio photoactuator can reach 35-50%, far reaching the contraction ratio of the left ventricle of a normal heart (20-30%). Therefore, the negative Poisson's ratio photoactuator can effectively assist the contraction of the left ventricle; by taking a video of a negative Poisson's ratio photoactuator beating on the heart with a high-speed camera, it was calculated that the longitudinal contraction of the negative Poisson's ratio photoactuator can achieve the same frequency as the heart, with an error of less than 5ms; tests showed that after treatment with a left ventricular assist device, the animals' LVEDV decreased by 60-80%, LVESV decreased by 70-90%, EF increased by 40-50%, and FS increased by 50-60%.

Claims

1. A left ventricular assist device with an electrocardiogram-light-controlled switch, characterized in that: These include ECG devices, infrared lasers, negative Poisson's ratio optical actuators, and PLCs; The negative Poisson's ratio optical actuator 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 contracts when irradiated by infrared laser light emitted from the optical fiber, and rebounds after the infrared laser light is removed; An infrared laser is used to emit laser light toward the rear end of an optical fiber in the negative Poisson's ratio optical actuator; The ECG device and infrared laser are connected to the PLC at the same time. The PLC obtains the current ECG of the monitored object in real time through the ECG device. Every time a new set of P points, Q points, R points, S points, and T points is obtained, the infrared laser is controlled to start after the time corresponding to the set of S points with a delay of t1 and continue to start for t2 time. Point P is the starting point of the atrial contraction phase of the monitored subject, point Q is the mid-point of the atrial contraction phase of the monitored subject, point R is the end point of the atrial contraction phase of the monitored subject and the starting point of the ventricular contraction phase of the monitored subject, point S is the mid-point of the ventricular contraction phase of the monitored subject, and point T is the end point of the ventricular contraction phase of the monitored subject; The process of obtaining t1 is as follows: obtain the historical electrocardiogram of the monitored object, obtain the time intervals between all adjacent S points and Q points in the historical electrocardiogram, and calculate the average value to obtain t1; The process of obtaining t2 is as follows: obtain the historical electrocardiogram of the monitored object, obtain the time intervals between all adjacent T points and R points in the historical electrocardiogram, and calculate the average value to obtain t2; The number of heartbeats in the historical electrocardiogram is more than 200, and the test duration is 100-200s.

2. A left ventricular assist device with an electrocardiogram-light-controlled switch according to claim 1, characterized in that: The ECG device is a Bluetooth ECG device.

3. The left ventricular assist device with an electrocardiogram-light-controlled switch 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.

4. A left ventricular assist device with an electrocardiogram-light-controlled switch according to claim 3, 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.

5. The left ventricular assist device with an electrocardiogram-light-controlled switch according to claim 1, characterized in that: 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.

6. A left ventricular assist device with an electrocardiogram-light-controlled switch according to claim 5, characterized in that: The diameter of the optical fiber is 0.25-2 mm.

7. The left ventricular assist device with an electrocardiogram-light-controlled switch according to claim 1, characterized in that: The length of the liquid crystal elastomer sleeve is 8-22 cm.

8. The left ventricular assist device with an electrocardiogram-light-controlled switch according to claim 1, characterized in that: 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.

9. A left ventricular assist device with an electrocardiogram-light-controlled switch according to claim 8, 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.

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