Light-driven liquid crystal elastomer tumbler and nonlinear dynamic control method thereof

Abstract

The invention relates to the technical field of intelligent materials and structural dynamics, solves the technical problems that an existing tumbler structure is lack of self-continuous motion ability and depends on external energy, and particularly relates to a light-driven liquid crystal elastomer tumbler and a nonlinear dynamics control method thereof. Self-continuous swinging under illumination of certain intensity is realized by utilizing light response design of the liquid crystal elastomer and coupling of nonlinear restoring force, and application is performed by utilizing regular movement of the liquid crystal elastomer. The tumbler structure can generate a state alternating process from swinging out of an illumination area to swinging back to the illumination area under the condition of specific light source intensity, and the change amplitude of standing and inclining alternation can be changed by adjusting illumination parameters. According to the tumbler structure, the limitation problem of a traditional tumbler can be solved, the tumbler structure can achieve self-continuous movement under the condition that the tumbler structure does not depend on external periodic stimulation, and the application of the tumbler structure is expanded.

Description

Technical Field

[0001] This invention relates to the field of smart materials and structural dynamics, and in particular to a light-driven liquid crystal elastomer roly-poly toy and its nonlinear dynamic control method. Background Technology

[0002] The roly-poly toy, an ancient Chinese children's toy, swings back and forth around its equilibrium position and gradually comes to rest when subjected to external disturbances. This structure is highly sensitive to low-frequency excitations and also possesses the core function of "anti-tipping." However, its use is often limited by its existing design, requiring additional electrical energy or power-generating components to maintain continuous movement. Furthermore, traditional roly-poly toys lack scalability; while some electronic improvements (such as the addition of lights and music) exist, they are essentially passive responses to physical shaking and cannot actively perform tasks or be applied to other fields to solve other problems. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a light-driven liquid crystal elastomer roly-poly toy and its nonlinear dynamic control method, solving the technical problems of existing roly-poly structures relying on external energy sources and lacking self-sustaining motion capabilities. This invention achieves self-sustaining oscillation under certain intensity light illumination through photoresponse design and nonlinear restoring force coupling, and utilizes its regular motion to develop various applications.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a light-driven liquid crystal elastomer roly-poly toy, comprising a cylindrical limiting base containing a concave arc surface track and a shell covering the limiting base. The front of the shell is provided with a light-illuminating window. A hollow space is formed between the shell and the limiting base to accommodate a motion control component disposed on the limiting base. The motion control component corresponds to the light-illuminating window and is on the same vertical axis of symmetry as the light-illuminating window when there is no light source. The light intensity in the current light adjustment system is determined by monitoring the swing amplitude of the motion control component in a self-continuous swing state. The motion control component includes a contact base placed on a concave arc track and a column vertically fixed at the center of the top of the contact base. A counterweight box with a through hole in its center is provided on the column and slides through the through hole to form a sliding fit with the column. A liquid crystal elastomer is provided between the counterweight box and the top of the column, which drives the counterweight box to slide up and down along the column by telescopic movement. The two ends of the liquid crystal elastomer are respectively connected to the counterweight box and the top of the column to form a suspension structure.

[0005] This invention utilizes the property of liquid crystal elastomer materials to contract and deform along their length under light stimulation, constructing a novel roly-poly structure. This roly-poly structure can alternate between "swinging out of the illuminated area" and "swinging back into the illuminated area" under specific light source intensities, and the amplitude of this alternation between standing and tilting can be changed by adjusting the light parameters. Furthermore, this invention reduces the limitations of the limited applicability caused by the single motion mode of traditional materials. Therefore, the design method and concept proposed in this invention can overcome the complexity and cost limitations of traditional light environment monitoring systems, and is expected to promote the development of environmental monitoring, agricultural production, and other fields.

[0006] Furthermore, the motion control component's motion state under illumination or non-illumination conditions is as follows: When the motion control component is illuminated by the light window, the liquid crystal elastomer gradually contracts and pulls the counterweight box to slide upward to raise the center of mass of the motion control component and drive it to swing to one side until the motion control component swings out of the light window and is in a non-illuminated environment. When the motion control component is in a non-light environment, the liquid crystal elastomer gradually recovers its contraction, and at the same time, the counterweight box slides down under the action of gravity to lower the center of mass of the motion control component. As the motion control component continues to swing to the farthest point on one side, it gradually swings back to the light window and is illuminated again. When the motion control component is exposed to light again, the liquid crystal elastomer contracts again and pulls the counterweight box to slide upward to raise the center of mass of the motion control component. Due to inertia, the motion control component continues to swing to the other side and moves out of the light window, and is once again in a non-light environment. When the motion control component is in a non-light environment again, the liquid crystal elastomer resumes contraction, and the counterweight box slides down again under the action of gravity to lower the center of mass of the motion control component. After swinging to the farthest point on the other side, the motion control component gradually swings back to the light window and is illuminated again, thereby realizing the self-continuous swing of the motion control component under constant light conditions.

[0007] Furthermore, the top of the column extends into the housing and is fixedly connected to a lower pressure plate. An upper pressure plate, which is superimposed on the lower pressure plate, is adjustablely connected above the lower pressure plate by a wing screw. The upper end of the liquid crystal elastomer extends between the lower pressure plate and the upper pressure plate and is fixed to the top of the column by clamping.

[0008] Furthermore, the top of the counterweight box is adjustablely connected to an adjusting pressure plate via wing screws. The adjusting pressure plate has through holes on both sides corresponding to the diameter of the liquid crystal elastomer, and the lower end of the liquid crystal elastomer extends to the counterweight box through the through holes and is clamped and fixed by the adjusting pressure plate.

[0009] Furthermore, the light window on the front of the outer casing is an inverted triangular opening, and a transparent plate is installed at the opening. The front and back sides of the outer casing are opaque, while the left and right sides are transparent. The upper edge of the limiting base is provided with a shallow groove that fits into the outer shell.

[0010] The technical solution also provides a closed space environment monitoring and alarm device, which utilizes the light-driven liquid crystal elastomer tumbler to automatically control the working status of external devices by autonomously controlling the continuous swing of its internal motion control components, so as to intuitively monitor and judge the current lighting conditions in the closed space. The monitoring and alarm device includes a spring-loaded electric gate installed on a limit base or housing, and a power supply and a buzzer alarm electrically connected to the spring-loaded electric gate to form a circuit. When the motion control component is exposed to light of a preset intensity, the liquid crystal elastomer contracts and pulls the counterweight box upward to change the center of mass position of the motion control component, thereby driving it to swing to one side to trigger the spring electric gate and activate the buzzer alarm to remind people in the enclosed space to make adjustments. When the environment changes and the light and heat decrease, the contraction of the liquid crystal elastomer begins to recover, the motion control component is pulled back to the center by the counterweight box, the spring electric gate is automatically opened, and the buzzer alarm stops working.

[0011] The technical solution also provides a self-continuous roly-poly toy, which utilizes the light-driven liquid crystal elastomer roly-poly toy to generate a bell sound by autonomously controlling the self-continuous swing of its internal motion control components and achieving reciprocating impact; the self-continuous roly-poly toy includes a bell installed on the outer shell.

[0012] By employing the above technical solution, the present invention provides a light-driven liquid crystal elastomer roly-poly toy and its nonlinear dynamic control method, which has at least the following beneficial effects: 1. This invention enables a roly-poly toy to alternate between "swinging out of the illuminated area" and "swinging back into the illuminated area" under specific light source intensity conditions, and the amplitude of the alternation between standing and tilting can be changed by adjusting the structural parameters of the roly-poly toy. This overcomes the limitations of the complexity and high cost of traditional lighting environment monitoring systems and is expected to promote the development of environmental monitoring, agricultural production, and other fields.

[0013] 2. This invention, through its self-stabilizing tumbler structure, offers several advantages. First, its stable state simplifies placement during operation, reducing the impact of the installation environment on structural design. This means the tumbler structure can be easily deployed in outdoor environments, allowing for more diverse installation methods to meet different needs. This flexibility enables the tumbler structure to adapt to various environments, providing more placement options to satisfy diverse requirements.

[0014] 3. This invention can overcome the limitations of traditional roly-poly toys, enabling the roly-poly structure to achieve self-continuous movement without relying on external power sources and external control circuits, and also freeing it from the limitation of only being able to passively respond to physical shaking. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is an internal cross-sectional view of the structure of the light-driven liquid crystal elastomer roly-poly toy in its initial state in Embodiment 1 of the present invention; Figure 2 This is a front view of the light-driven liquid crystal elastomer roly-poly toy in Embodiment 1 of the present invention; Figure 3 This is Embodiment 1 of the present invention. Figure 1 Enlarged view of region A in the middle; Figure 4 This is Embodiment 1 of the present invention. Figure 1 Enlarged view of region B in the middle; Figure 5 This is a side cross-sectional view of the structure of the light-driven liquid crystal elastomer roly-poly toy in its initial state in Embodiment 1 of the present invention; Figure 6 This is an internal cross-sectional view of the structure of the light-driven liquid crystal elastomer roly-poly toy in Embodiment 1 of the present invention, showing its movement under certain lighting conditions; Figure 7 This is a schematic diagram showing the swing angle in a stable state in Embodiment 2 of the present invention; Figure 8 This is a schematic diagram of the swing angle in the swing state in Embodiment 2 of the present invention; Figure 9 This is a schematic diagram illustrating the effect of light intensity on amplitude and frequency in Embodiment 2 of the present invention; Figure 10 This is a schematic diagram illustrating the effect of the counterweight box mass on amplitude and frequency in Embodiment 2 of the present invention; Figure 11 This is a schematic diagram of the environmental monitoring equipment in Embodiment 3 of the present invention; Figure 12 This is Embodiment 3 of the present invention. Figure 8 Enlarged view of region C in the middle; Figure 13 This is a schematic diagram of the structure of the self-sustaining roly-poly toy in Embodiment 4 of the present invention.

[0016] In the picture: 1. Outer shell; 2. Motion control components; 20. Contact base; 21. Counterweight box; 211. Adjusting pressure plate; 22. Column; 221. Lower pressure plate; 222. Upper pressure plate; 23. Liquid crystal elastomer; 3. Limiting base; 4. Shallow grooves and recesses; 5. Transparent panel; 6. Power supply; 61. Spring-loaded electric switch; 62. Buzzer alarm; 7. Bell; 8. Lighting window. Detailed Implementation

[0017] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This will allow for a full understanding of how the present application uses technical means to solve technical problems and achieve technical effects, and to facilitate its implementation.

[0018] In this embodiment, liquid crystal elastomers, as photosensitive smart materials, can achieve reversible deformation through light stimulation. They have attracted considerable attention in the field of soft robotics in recent years, combining the light / thermal responsiveness of liquid crystals with the high elasticity of rubber. Their shape-changing property in response to temperature stimulation can be utilized to achieve periodic autonomous control of structural motion. The self-sustaining characteristic of liquid crystal elastomers is one of their most disruptive capabilities, meaning that the material can generate autonomous, continuous periodic motion under a constant external energy input, thus eliminating the need for external control circuits.

[0019] Therefore, this embodiment utilizes the elasticity of liquid crystal to design a new optical drive structure, which can overcome the problems of the traditional roly-poly structure, enabling the roly-poly structure to achieve its own continuous movement without relying on external power supply and external control circuit, and also getting rid of its limitation of only being able to passively respond to physical shaking.

[0020] Example 1 This embodiment proposes a light-driven liquid crystal elastomer roly-poly toy. Through photoresponse design and coupling with nonlinear restoring force, it achieves self-sustaining oscillation under a certain intensity of light illumination, and utilizes its inherent regular motion for various applications. For example... Figures 1-6As shown, the proposed light-driven liquid crystal elastomer roly-poly toy consists of a shell 1, a motion control component 2, a limiting base 3, and a light-illuminating window 8, among other core structures. The motion control component 2 comprises a contact base 20, a counterweight box 21, an adjusting pressure plate 211, a column 22, a lower pressure plate 221, an upper pressure plate 222, and a liquid crystal elastomer 23. A shallow groove 4 is provided on the upper edge of the limiting base. The front and back surfaces of the shell 1 are opaque, while the left and right surfaces are transparent. The light-illuminating window 8 on the front of the shell 1 is an inverted triangular opening, with a transparent plate 5 installed at the opening. Figure 2 As shown.

[0021] In this embodiment, the outer shell 1 is fixed to the limiting base 3 by engaging with the shallow groove 4. The internal space formed between the outer shell 1 and the limiting base 3 is used to accommodate the motion control component 2, such as... Figure 1 As shown.

[0022] In this embodiment, the column 22 of the motion control component 2 is vertically fixed to the center of the contact base 20, and the bottom of the column 22 is rigidly connected to the contact base 20 by welding to form a whole. A counterweight box 21 with a central through hole is sleeved on the column 22, and the counterweight box 21 slides against the column 22 through the through hole, allowing relative sliding between the column 22 and the counterweight box 21. The top of the column 22 is connected to the upper end of the liquid crystal elastomer 23, and the lower end of the liquid crystal elastomer 23 is connected to the upper end of the counterweight box 21. After connection, the counterweight box 21 can move autonomously up and down under the extension and retraction of the liquid crystal elastomer 23.

[0023] In this embodiment, the top of the column 22 is connected to the upper end of the liquid crystal elastomer 23 via an upper pressure plate 222 and a lower pressure plate 221. The top of the column 22 extends and is welded to the lower pressure plate 221, with the liquid crystal elastomer 23 only passing around the outer surface of the column 22. The lower pressure plate 221 is connected to the upper pressure plate 222 via wing screws, and the pressure can be adjusted via the wing screws. The upper pressure plate 222 has a threaded through hole corresponding to the thread of the lower pressure plate 221. The upper end of the liquid crystal elastomer 23 is clamped and fixed to the top of the column 22 after being tightened by the lower pressure plate 221 and the upper pressure plate 222 with wing screws. After the upper pressure plate 222 and the lower pressure plate 221 are connected, they form a whole with the column 22. Because the upper end of the liquid crystal elastomer 23 is clamped, the upper end of the liquid crystal elastomer 23 can withstand the tension below. Figure 3 As shown.

[0024] In this embodiment, the adjusting pressure plate 211 has through holes on both sides, the diameter of which corresponds to the liquid crystal elastomer 23, allowing the liquid crystal elastomer 23 to extend directly to the counterweight box 21. The counterweight box 21 has internally recessed threads on both sides of its upper surface for connection and fixation with the adjusting pressure plate 211. The adjusting pressure plate 211 has two threaded tube through holes on both sides corresponding to the threads of the counterweight box. The adjusting pressure plate 211 is connected to the counterweight box 21 via wing screws, and the pressure can be adjusted using these screws. The lower end of the liquid crystal elastomer 23 is clamped and fixed to the bottom of the counterweight box 21 by the adjusting pressure plate 211 and the counterweight box 21 using wing screws. Figure 4 As shown. The adjusting plate 211 and the counterweight box 21 are connected to form a whole. Because the liquid crystal elastomer 23 is clamped, the expansion and contraction of the liquid crystal elastomer 23 can drive the counterweight box 21 to move up and down along the column 22. The two ends of the liquid crystal elastomer 23 are respectively connected to the bottom of the counterweight box 21 and the top of the column 22 to form a suspension structure. The deformation of the light-responsive liquid crystal elastomer 23 under light is directly transmitted to the counterweight box 21 to change the position of the center of mass of the structure.

[0025] In this embodiment, the limiting base 3 and the contact base 20 of the motion control component 2 cooperate to form a limiting structure, that is, the upper surface of the limiting base 3 is a concave arc track surface, and the contact base 20 is a semi-cylinder with a convex bottom, such as... Figure 1 As shown. The convex semi-cylindrical contact base 20 sits on the concave arc track surface of the limiting base 3 to form point contact. This not only helps maintain the continuous reciprocating motion of the motion control component 2, but also reduces friction during autonomous motion control. The counterweight box 21 can be driven to slide up and down to change the overall center of gravity position simply by utilizing the contraction and deformation of the liquid crystal elastomer 23 under external light stimulation. Furthermore, it can limit the swing angle of the contact base 20, such as... Figure 6 As shown.

[0026] In this embodiment, the liquid crystal elastomer 23 has photothermal response characteristics. When stimulated by external light and heat, it will shrink and deform. The light window 8 can realize the light environment of the inverted triangle area, while the other areas are non-light environment.

[0027] In this embodiment, the motion control component 2 corresponds to the illumination window 8 and is on the same vertical axis of symmetry as the illumination window 8 when there is no light source.

[0028] In this embodiment, the liquid crystal elastomer 23 and the column 22 are arranged in parallel, and the liquid crystal elastomer 23 and the column 22 do not intersect each other during operation.

[0029] In this embodiment, the counterweight box 21 is symmetrically inserted through the column 22 and makes smooth contact. During operation, the counterweight box 21 can slide freely back and forth along the column 22 through the central through hole, where friction is negligible.

[0030] The working principle of the light-driven mechanism in this embodiment is as follows: In the initial state, the liquid crystal elastomer 23 is in a relaxed state, and the counterweight box 21 pulled by the liquid crystal elastomer 23 is at a specific height. At this time, the structure is in a state of static equilibrium, and the motion control component 2 is self-stabilized in a stationary position. When the light source shines on the roly-poly structure through the light window 8, the motion control component 2 is illuminated by the light window 8, and the liquid crystal elastomer 23 gradually contracts and pulls the counterweight box 21 to slide upward to raise the center of mass position of the motion control component 2 and drive it to swing to one side until the motion control component 2 swings out of the light window and is in a non-illuminated environment.

[0031] When the motion control component 2 is in a non-light environment, the liquid crystal elastomer 23 gradually recovers its contraction, and at the same time, the counterweight box 21 slides down under the action of gravity to lower the center of mass of the motion control component. As the motion control component 2 continues to swing to the farthest point on one side, it gradually swings back to the light window 8 and is illuminated again.

[0032] When the motion control component 2 is illuminated again, the liquid crystal elastomer 23 contracts again and pulls the counterweight box 21 upward to raise the center of mass of the motion control component 2. Due to inertia, the motion control component 2 continues to swing to the other side, moving out of the illumination window 8 and returning to a non-illuminated environment. When the motion control component 2 is in a non-illuminated environment again, the liquid crystal elastomer 23 contracts again, and the counterweight box 21 slides downward again under gravity to lower the center of mass of the motion control component 2. After swinging to the farthest point on the other side, the motion control component 2 gradually swings back to the illumination window 8 and is illuminated again. This swinging motion and alternation of illumination and non-illumination states are repeated, forming a continuous, periodic, and autonomous alternation of illumination and non-illumination states under constant illumination conditions, thus obtaining a self-moving light-driven liquid crystal elastomer tumbler structure. If the threshold of illumination intensity is reduced or the size of the illumination window is changed, the self-moving light-driven liquid crystal elastomer tumbler structure will eventually stop moving due to damping dissipation.

[0033] In this embodiment, since the degree of contraction of the liquid crystal elastomer 23 is related to the photothermal intensity, the photothermal intensity and duration can be determined by monitoring the offset amplitude of the roly-poly structure. Furthermore, because its movement is a self-continuous oscillation, it can continuously obtain updated information about its current state without manual correction, making it more suitable for determining the photothermal intensity and duration in the current temperature or light regulation system.

[0034] Example 2 This embodiment, based on the light-driven liquid crystal elastomer tumbler proposed in Embodiment 1, proposes a nonlinear dynamic control method. Based on the control equations for the tumbler's periodic motion, the frequency of its periodic motion can be adjusted by controlling the light intensity. This method is used to control the autonomous motion of the light-driven liquid crystal elastomer tumbler under constant light intensity. The method includes the following steps: S1. Prepare and assemble the roly-poly structure, and measure the vertex angle of the illumination window. When exposed to light of a certain intensity, the temperature difference of the liquid crystal elastomer 23 increases due to the photothermal effect. It gradually rises, and undergoes contraction deformation, moving along the top of column 22.

[0035] S2. Measure the mass of counterweight box 21 based on S1. Mass of contact base 20 Moment of inertia of motion control component 2 Length of column 22 The length of the liquid crystal elastomer 23 in its initial state and the rotational damping coefficient of motion control component 2 The rolling friction resistance torque of the contact base 20 The radius of the concave arc track surface on the upper surface of the limiting base 3 is... The radius of the contact base 20 And thus determine the dynamic control equations of motion control component 2.

[0036] In this embodiment, the motion control component 2 is initially in an equilibrium position. When there is external disturbance or the center of mass deviates from the geometric center, the motion control component 2 will revolve around the equilibrium position. The motion control component 2 oscillates and swings. During the oscillation process, the motion control component 2 is subjected to a gravitational torque. Support force Rotational damping torque and rolling friction torque Therefore, the dynamic control equation of motion control component 2 can be calculated according to formula (1), which is as follows: (1) in, It represents angular acceleration, which is angular displacement. Regarding time The second derivative of the rotational damping torque. It is generally related to the rotational angular velocity. To simplify the calculation, it is assumed that the rotational friction torque is linearly related to the angular velocity and can be calculated according to formula (2). Formula (2) is as follows: (2) in, It represents angular velocity, which is angular displacement. Regarding time The first derivative of gravitational torque. The length of the liquid crystal elastomer 23 Angular displacement of motion control component 2 and the position located on the limiting base 3 Decision made. It's important to note that, for simplicity, we assume there is no slippage during the rolling process. Through geometric analysis, the gravitational torque... It can be calculated according to formula (3), which is as follows: (3) in, It is the angle between the track radius corresponding to the contact point of the contact base 20 on the limiting base 3 and the vertical direction. This is the acceleration due to gravity. Based on the condition that the arc lengths are equal in a no-slip condition, the position... It can be calculated according to formula (4), which is as follows: (4) In this embodiment, due to the length of the liquid crystal elastomer 23 It varies with temperature difference and is determined by light-driven strain, which can be calculated according to formula (5), as follows: (5) in, It is the light-driven strain of the liquid crystal elastomer 23.

[0037] Combining formulas (1)–(5), the dynamic control equations of motion control component 2 can be further calculated according to formula (6), which is as follows: (6) S3. Measure the specific heat capacity of the liquid crystal elastomer 23. Thermal conductivity and shrinkage coefficient Light intensity Record the ambient temperature at room temperature This allows for the determination of the dynamic response of the liquid crystal elastomer 23, thereby enabling the determination of the roly-poly structure at a certain angular displacement. Time-driven strain .

[0038] The light-driven strain in this embodiment The temperature of the liquid crystal elastomer 23 With ambient temperature temperature difference Decision. Assuming light-driven strain. With temperature difference Linear correlation can be calculated according to formula (7), which is as follows: (7) in, It is the coefficient of thermal shrinkage of the liquid crystal elastomer 23.

[0039] Because the light-irradiated area is an inverted triangle, the liquid crystal elastomer 23 as a whole can simultaneously enter or leave the light-irradiated area. Furthermore, the photothermally responsive liquid crystal elastomer 23 rapidly exchanges heat with its surrounding environment, ensuring a uniform temperature distribution across its relatively thin structure. Therefore, at any given moment, the instantaneous temperature difference is considered uniform across the entire liquid crystal elastomer 23.

[0040] When exposed to light, the liquid crystal elastomer 23 converts light energy into heat energy. According to the second law of thermodynamics, heat is transferred unidirectionally from a high-temperature substance to a low-temperature substance; the temperature difference in the liquid crystal elastomer 23... Calculated according to formula (8), formula (8) is as follows: (8) In addition, there is a relative temperature difference Formula (8) can be rewritten as formula (9), which is as follows: (9) in, It is the thermal conductivity coefficient. It is specific heat capacity. It is further parameterized using two characteristic thermal scales: steady-state temperature difference. (Maximum achievable temperature difference) and inherent relaxation time constant Equation (9) can be further expressed as calculation formula (10), which is as follows: (10) in, The relaxation dynamics govern the thermal equilibrium between the photothermally responsive liquid crystal elastomer and its surrounding environment. Relaxation time constant. The shorter the length, the faster the thermal response, and such a system can reach thermal equilibrium with minimal delay.

[0041] When the motion control component 2 moves from the non-illuminated area (with instantaneous temperature difference) When moved to the illuminated area, the temperature difference of the liquid crystal elastomer 23 The temperature difference during illumination can be determined by solving equation (10). It can be calculated according to formula (11), which is as follows: (11) It should be noted that in the continuous non-illuminated area, the temperature of the liquid crystal elastomer 23 is the same as the ambient temperature, i.e., the initial transient temperature difference. When the liquid crystal elastomer 23 is subjected to a transient temperature difference... When the illuminated area moves to the non-illuminated area, the temperature difference It can be calculated according to formula (12), which is as follows: (12) in, and These represent the duration of the current process.

[0042] S4. Based on the dynamic control equations and the dynamic response of the liquid crystal elastomer, establish a motion control component to characterize angular displacement in the illuminated or unilluminated areas. and time The motion control equations relating the nonlinear relationships between them.

[0043] In equation (6), the torque balance equation of motion control component 2 varies with the light-driven strain. By combining equations (7), (11), and (12), the motion control equations of motion control component 2, determined by calculation formulas (13) and (14), can be obtained. The motion control equation for the illuminated area is calculated according to formula (13), which is as follows: (13) The motion control equations for the non-illuminated area are calculated according to formula (14), which is as follows: (14) Therefore, the mass of the counterweight box 21 is selected. Mass of contact base 20 Moment of inertia of motion control component 2 The length of column 22 and the length of the liquid crystal elastomer 23 in its initial state Measure the rotational damping coefficient of motion control component 2 Rolling friction resistance torque of contact base 20 The upper surface of the selected limiting base 3 is a concave circular arc track surface with a radius of... and the radius of the contact base 20 The specific heat capacity of liquid crystal elastomer 23 was selected. and heat transfer coefficient Under the condition of a fixed ambient temperature In the process, the self-control state of motion control component 2 is only related to the light intensity. This is relevant. When the light intensity is high, the heat absorbed by the liquid crystal elastomer 23 is insufficient to maintain the self-control process of the roly-poly structure.

[0044] S5. Based on the motion control equation, the swing amplitude and frequency of the self-sustaining oscillation of the roly-poly structure are adjusted by controlling the light intensity, and the automatic transition between the static mode and the self-sustaining oscillation mode is controlled.

[0045] Based on the nonlinear dynamic control method proposed in this embodiment, an optical drive structure is designed. In order to simplify the problem, improve numerical stability, and realize parameter comparison and universality, the parameters and calculation formulas in the above steps are dimensionless and numerical simulation calculations are performed using MATLAB software.

[0046] Define the following dimensionless parameters: , , , , , , , , , , , , and The motion control equations (13) and (14) of the motion control component 2 can be rewritten as calculation formulas (15) and (16). The motion control equations under illumination are calculated according to formula (15), which is as follows: (15) The dynamic control equations under non-illuminated conditions are calculated according to formula (16), which is as follows: (16) The temperature evolution calculation formulas (11) and (12) can be rewritten as calculation formulas (17) and (18). The calculation for illumination is based on formula (17), which is as follows: (17) When there is no light, the calculation is performed according to formula (18), which is as follows: (18) To investigate the influence of parameters on the structural state of the roly-poly toy, this embodiment takes photothermal intensity as an example to study the effect of the magnitude of photothermal intensity on the structural state of the roly-poly toy, given the dimensionless mass of the counterweight box 21. The length of the liquid crystal elastomer in its initial state Column length 22 radius of concave circular arc track surface Moment of inertia Rotational damping coefficient Rolling friction resistance torque The shrinkage coefficient of liquid crystal elastomers Angle of the vertex of the lighting window Initially, motion control component 2 is stationary, and the light intensity is adjusted. Starting from 0 and gradually increasing, the influence of light intensity on the working state of the roly-poly structure can be obtained by solving according to formulas (15)-(18).

[0047] When the light intensity is too low, the energy input to the system is insufficient to maintain the system's continuous oscillation, and eventually, due to damping dissipation, it reaches a stable stationary state, such as... Figure 7 As shown. When the light intensity is sufficiently high, the energy input to the system can sustain the system's continuous oscillating motion, eventually leading to a self-sustaining oscillation state, as... Figure 8 As shown.

[0048] The example selects dimensionless light intensity. A demonstration was conducted, and the analysis results under dimensionless parameter combinations with different light intensity values ​​showed that, with increasing light intensity... With the increase of light intensity, the motion control components gradually transition from a static mode to a self-continuous oscillation mode, where the critical light intensity... .when At that time, insufficient light intensity would cause the roly-poly structure to fail to maintain its self-sustaining motion. At that time, the roly-poly structure can swing continuously. Simultaneously, under the condition that the roly-poly structure can form a self-sustaining swing, as the light intensity increases, the swing amplitude of the motion control component 2 increases. With frequency Continuously increasing, such as Figure 9 As shown. Therefore, given that other parameters are fixed, the light intensity can be adjusted. This controls the swing amplitude and frequency of the motion control component 2, and also adjusts the light intensity. The self-righting structure is controlled to stop working.

[0049] Figure 9 The results are only obtained under the condition that the materials and structure are determined, taking into account the light intensity. The impact on the roly-poly structure. If the materials and structure are uncertain, the influence of various parameters on the roly-poly structure can be considered from multiple perspectives. For example, the mass of the counterweight box 21. Mass of contact base 20 Moment of inertia of motion control component 2 Column length 22 and the length of the liquid crystal elastomer 23 in its initial state The rotational damping coefficient of motion control component 2 Rolling friction resistance torque of contact base 20 The upper surface of the limiting base 3 is a concave arc track surface with a radius of... and the radius of the contact base 20 These conditions can all be used to control the amplitude of the roly-poly toy's oscillation. and frequency This allows it to be suitable for various scenarios with different needs. For example, Figure 10 The weight of the counterweight box was demonstrated. The amplitude of the tumbler's oscillation and frequency The diagram illustrates the effect of the weight box's mass. With other dimensionless parameters fixed, the effect varies with the mass of the weight box. As the mass of the counterweight box increases, both the amplitude and frequency continuously increase. When the amplitude is small, the system's oscillation becomes zero. This means that the amplitude and frequency of the self-oscillating roly-poly toy, as well as its motion pattern, can be adjusted by changing the mass of the counterweight.

[0050] Example 3 This embodiment provides a design scheme based on Embodiments 1 and 2, namely, a monitoring and alarm device for enclosed spaces (such as inside a vehicle). A buzzer alarm 62 is installed by intermittently drilling holes from the center to the edge of the limiting base 3. To connect the buzzer alarm 62 to the power supply 6, the device generates a feedback effect when exposed to a certain level of light, thus providing a direct monitoring and judgment of the current lighting conditions in the space. The monitoring and alarm device in this embodiment is placed on a platform, and the buzzer alarm 62 can be replaced with other electrical components such as a vibrator as needed.

[0051] like Figure 11 and Figure 12 As shown, in the initial state without light, the liquid crystal elastomer 23 is in a relaxed state, and the counterweight box 21 pulled by the liquid crystal elastomer 23 is in a specific position. At this time, the structure is in a state of static equilibrium. When exposed to light, the liquid crystal elastomer 23 begins to contract, and the counterweight box 21 is pulled upward by it, causing the center of mass of the structure to rise, thus causing the roly-poly toy to swing continuously until the liquid crystal elastomer 23 contracts to a certain extent. At this point, the spring-loaded electric gate 61 is triggered, the circuit becomes closed, and the buzzer alarm 62 is activated to alert personnel in the environment to make adjustments.

[0052] When the environment changes and the light intensity decreases, the liquid crystal elastomer 23 recovers its contraction, and the roly-poly structure begins to return to its upright position. When the roly-poly structure returns to its upright position to a certain extent, the spring-loaded gate 61 automatically opens, and the buzzer alarm 62 stops working. When the equipment is not exposed to light or the offset caused by light does not reach the alarm threshold, the alarm cannot be triggered, but the structure can still continuously swing. Therefore, the structure's normal operating status can be determined based on its swing, achieving self-detection of the structure's working status. When it is necessary to adjust the activation conditions of the buzzer alarm 62, the installation position of the buzzer alarm 62 can be adjusted through multiple small holes to meet the sensing alarm requirements under different light intensity conditions.

[0053] Furthermore, this system can be connected to a temperature control or lighting control system to achieve coordinated operation of the two systems. This embodiment utilizes the characteristic of the self-righting structure to autonomously control the movement of its internal components, thereby achieving automatic control of the operating status of external equipment. The automatic control process is as follows: When the motion control component changes from a static state to a moving state, the self-control state of the tumbler structure is triggered, and the tumbler generates a periodic reciprocating motion process. When the tumbler moves to a certain degree of offset state, the external device connected to it is triggered to work. As the tumbler structure returns to its upright position, the external device circuit also returns to the open circuit state, and the external device is in a non-working state. Under the control of the tumbler, the external device generates a continuous, periodic alternation between working and non-working states.

[0054] Example 4 This embodiment provides a design scheme based on Embodiments 1 and 2, namely a self-contained roly-poly toy. By adding a bell 7 to the outer shell 1, the device shakes to a certain extent and then hits the bell to produce a sound.

[0055] like Figure 13 As shown, when illuminated within a specific range of natural light intensity, the liquid crystal elastomer 23 begins to contract, causing the counterweight box 21 to move upwards under its pull. This raises the center of gravity of the motion control component, resulting in the roly-poly toy continuously swinging and colliding with the bell during its movement. This continues until the liquid crystal elastomer 23 contracts to a certain extent, at which point it is no longer exposed to light. At this point, the roly-poly toy begins to return to its upright position, colliding with the bell 7 again during its return-to-right movement, thus continuously triggering the bell sound. Based on this, a toy that continuously moves under a certain light intensity environment can be obtained.

[0056] The working principle of the self-continuous roly-poly toy in this embodiment is as follows: Based on the continuously reciprocating motion state autonomously controlled by the light-driven liquid crystal elastomer roly-poly toy in Embodiment 1, the self-continuous roly-poly toy is designed accordingly. Initially, the motion control component is in a static equilibrium state and does not move. When it is exposed to light of a certain intensity and thus moves, the motion control component moves to the bell 7 and impacts it, causing the bell 7 to ring. Upon returning to the upright state, it impacts the bell 7 again, producing a ringing sound. In this way, the reciprocating motion continuously triggers the ringing sound.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Since the above embodiments are substantially similar to the method embodiments, their descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0058] The above embodiments provide a detailed description of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A light-driven liquid crystal elastomer roly-poly toy, comprising a limiting base (3) having a concave arc-shaped track and a housing (1) covering it, wherein the front of the housing (1) is provided with a light-illuminating window (8), characterized in that, The outer shell (1) and the limiting base (3) form a hollow space to accommodate the motion control component (2) that is movably set on the limiting base (3). The motion control component (2) corresponds to the light window (8) and is on the same vertical axis of symmetry with it when there is no light source. The light intensity in the current light adjustment system is determined by monitoring the swing of the motion control component (2) in the self-continuous swing state. The motion control component (2) includes a contact base (20) placed on a concave arc surface track and a column (22) vertically fixed at the center of the top of the contact base (20). The column (22) is provided with a counterweight box (21) with a through hole in its center, and a sliding fit is formed between the counterweight box (21) and the column (22) through the through hole. A liquid crystal elastomer (23) is provided between the counterweight box (21) and the top of the column (22) to drive the counterweight box (21) to slide up and down along the column (22) by its extension and retraction. The two ends of the liquid crystal elastomer (23) are respectively connected to the counterweight box (21) and the top of the column (22) to form a suspension structure.

2. The light-driven liquid crystal elastomer roly-poly toy according to claim 1, characterized in that, The motion control component (2) has the following motion states under both illuminated and non-illuminated environments: When the motion control component (2) is illuminated by the light window (8), the liquid crystal elastomer (23) begins to contract and pulls the counterweight box (21) to move upward to raise the center of mass of the motion control component (2) and drive it to swing to one side until the motion control component (2) moves out of the light window (8) and is in a non-illuminated environment. When the motion control component (2) is in a non-light environment, the liquid crystal elastomer (23) begins to recover and contract. At the same time, the counterweight box (21) moves downward under the action of gravity to lower the center of mass of the motion control component (2), and the motion control component (2) gradually swings back to the light window (8) after swinging to the farthest point on one side and is illuminated again. When the motion control component (2) is exposed to light again, the liquid crystal elastomer (23) contracts again and pulls the counterweight box (21) to move upward to raise the center of mass of the motion control component (2). Under the action of inertia, the motion control component (2) continues to swing to the other side until the motion control component (2) moves out of the light window (8) and is in a non-light environment again. When the motion control component (2) is in a non-light environment again, the liquid crystal elastomer (23) resumes contraction, and the counterweight box (21) moves downward under the action of gravity to lower the center of mass of the motion control component (2), and the motion control component (2) gradually swings back to the light window (8) after swinging to the farthest point on the other side and is illuminated again, so as to realize the self-sustaining swing of the motion control component (2) under constant light conditions.

3. The light-driven liquid crystal elastomer roly-poly toy according to claim 1, characterized in that, The top of the column (22) extends into the outer shell (1) and is fixedly connected to a lower pressure plate (221). An upper pressure plate (222) is connected above the lower pressure plate (221) by means of wing screws. The upper end of the liquid crystal elastomer (23) extends to the lower pressure plate (221) and is fixed to the top of the column (22) by clamping between it and the upper pressure plate (222).

4. The light-driven liquid crystal elastomer roly-poly toy according to claim 1, characterized in that, The top of the counterweight box (21) is connected to an adjusting pressure plate (211) by means of wing screws. The adjusting pressure plate (211) has through holes on both sides corresponding to the diameter of the liquid crystal elastomer (23). The lower end of the liquid crystal elastomer (23) extends to the counterweight box (21) through the through holes and is clamped and fixed by the adjusting pressure plate (211).

5. The light-driven liquid crystal elastomer roly-poly toy according to claim 1, characterized in that, The light window (8) located on the front of the outer shell (1) is an inverted triangle, and a transparent plate (5) is installed at the opening. The front and back sides of the outer shell (1) are opaque, and the left and right sides are transparent (5). The upper edge of the limiting base (3) is provided with a shallow groove (4) that fits into the outer shell (1).

6. A closed-space environment monitoring and alarm device, utilizing the light-driven liquid crystal elastomer roly-poly toy as described in any one of claims 1-5, characterized in that, The automatic control of the working status of external equipment is achieved by autonomously controlling the self-continuous swing of its internal motion control component (2), so as to intuitively monitor and judge the light and heat situation in the current enclosed space. The monitoring and alarm device includes a spring-loaded electric gate (61) installed on the limiting base (3) or the housing (1), and a power supply (6) and a buzzer alarm (62) electrically connected to the spring-loaded electric gate (61) to form a circuit. When the motion control component (2) is exposed to light of a preset intensity, the liquid crystal elastomer (23) is used to contract and pull the counterweight box (21) upward to change the position of the center of mass of the motion control component (2), so as to drive it to swing to one side to trigger the spring electric gate (61) and activate the buzzer alarm (62) to remind people in the enclosed space to make adjustments. When the enclosed space environment is changed, resulting in a decrease in light and heat, the contraction of the liquid crystal elastomer (23) begins to recover, the motion control component (2) is pulled back to center by the counterweight box (21), causing the spring electric gate (61) to automatically open, and the buzzer alarm (62) to stop working.

7. A self-sustaining roly-poly toy, utilizing a light-driven liquid crystal elastomer roly-poly toy as described in any one of claims 1-5, characterized in that, The bell is generated by the reciprocating impact through the self-continuous swing of its internal motion control component (2); The self-sustaining roly-poly toy includes a bell (7) mounted on the outer shell (1).

8. A nonlinear dynamic control method for realizing the light-driven liquid crystal elastomer tumbler as described in any one of claims 1-5, characterized in that, The method includes the following steps: S1. Prepare and assemble the roly-poly structure, and measure the vertex angle of the illumination window. The temperature difference of liquid crystal elastomer when exposed to light It gradually rises and undergoes contraction deformation, moving along the top of the column; S2. Measure the mass of the counterweight box. The quality of the contact base Moment of inertia of motion control components Length of the column Length of the liquid crystal elastomer in its initial state Rotational damping coefficient of motion control components Rolling friction resistance torque of the contact base The radius of the concave circular arc track surface and the radius of the contact base Therefore, the dynamic control equations of the motion control component are established, and the expression is: ； In the formula, It represents angular acceleration, which is angular displacement. Regarding time The second derivative; It represents angular velocity, which is angular displacement. Regarding time The first derivative; It is gravitational acceleration; It is the light-driven strain of the liquid crystal elastomer; It is the angular displacement of the motion control component; It is the angle between the track radius corresponding to the contact point of the contact base on the limiting base and the vertical direction; S3. Measure the specific heat capacity of the liquid crystal elastomer. Thermal conductivity Shrinkage coefficient and light intensity Record the ambient temperature at room temperature. This allows for the determination of the dynamic response of the liquid crystal elastomer, enabling the assessment of the roly-poly structure at any angular displacement. Time-driven strain ; S4. Based on the dynamic control equations and the dynamic response of the liquid crystal elastomer, establish a motion control component to characterize angular displacement in the illuminated or unilluminated areas. and time The motion control equations relating the nonlinear relationships between them; S5. Based on the motion control equation, the swing amplitude and frequency of the self-sustaining oscillation of the roly-poly structure are adjusted by controlling the light intensity, and the automatic transition between the static mode and the self-sustaining oscillation mode is controlled.

9. The nonlinear dynamics control method according to claim 8, characterized in that, In step S3, the specific process includes: When the motion control component is from a source with an instantaneous temperature difference When the non-illuminated area moves to the illuminated area, the temperature difference of the liquid crystal elastomer is determined. ,Right now: ； When the motion control component is from a source with a transient temperature difference When the illuminated area moves to the non-illuminated area, the temperature difference of the liquid crystal elastomer is determined. ,Right now: ； in, The steady-state temperature difference; The relaxation time constant; and These are the durations of the current process; The dynamic response of the liquid crystal elastomer as it moves from an unlit region to an illuminated region or vice versa is determined, i.e.: ； in, It is the coefficient of thermal shrinkage of liquid crystal elastomers.

10. The nonlinear dynamics control method according to claim 9, characterized in that, The motion control equation for the motion control component in the illuminated area is: ； The motion control equation for the motion control component in the non-illuminated area is: ； in, The instantaneous temperature difference of the liquid crystal elastomer when it switches from the non-illuminated area to the illuminated area; The instantaneous temperature difference of the liquid crystal elastomer when it switches from the illuminated area to the non-illuminated area.

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