A humidity actuator based on controllable motion of a fabric body

Abstract

The present application relates to the technical field of humidity actuator, and discloses a humidity actuator based on controllable motion form of fabric object, which comprises a humidity sensitive substrate and a humidity insensitive coating layer; the humidity sensitive substrate is a flexible fabric object; the humidity insensitive coating layer is a flexible material; the humidity insensitive coating layer is deposited on one side or both sides of the humidity sensitive substrate to form a pattern and partially cover the surface of the fiber material in the humidity sensitive substrate; the humidity expansion coefficient of the flexible fabric object is at least one order of magnitude higher than that of the flexible material. The humidity actuator can realize various motion forms, and by adjusting one or more of the weaving structure of the humidity sensitive substrate, the cutting angle of the humidity sensitive substrate and the pattern structure of the humidity insensitive coating layer, the curvature and direction controllable warping, bending and curling, and the chirality and pitch controllable spiral twisting can be realized. The preparation method of the humidity actuator is simple, the motion form is flexible and controllable, and the operability is strong.

Description

Technical Field

[0001] This invention relates to the field of humidity actuator technology, and more particularly to a humidity actuator based on a controllable motion form of fabric. Background Technology

[0002] An actuator is a device that undergoes reversible changes in response to external stimuli or disturbances, producing motion effects such as displacement, bending, curling, twisting, spiraling, stretching, expansion, and contraction. Through structural design and material selection, actuators have broad application prospects in soft robotics, sensing equipment, and wearable intelligence. Humidity, a physical quantity measuring the amount of moisture in the air, can be used to drive actuator movement. Currently, humidity actuators mainly have two structures: thin-film and fibrous.

[0003] Thin-film humidity actuators utilize the differences in the diffusion rate or hygroscopic expansion capacity of water molecules within layered thin-film materials to induce uneven deformation between the upper and lower layers, thereby generating bending motion. For example, this effect can be achieved using a bilayer humidity actuator (CN114658622B) prepared by bonding polyaspartic acid nanofiber membranes (CN109881476B) or bonito powder with an inert material. However, due to the isotropic nature of layered thin-film materials, uncontrolled bending or curling can easily occur at large scales, which also limits the shape and flexibility of the actuator.

[0004] Fibrous humidity actuators utilize a pre-twisted or spiraled approach, causing the material to expand and untwise upon absorbing moisture, thereby inducing extension, contraction, and torsional motions in the actuator. For example, this method is used in patent applications (CN109082742A and CN108588900A) for fabricating torsional actuators using sodium alginate fibers. However, this method is complex to fabricate, requiring high-precision control and high shear forces, and the motion pattern limits the actuator's shape, typically resulting in a fibrous structure.

[0005] In summary, humidity actuators can employ different structures to convert humidity changes into mechanical energy, but each structure has its unique advantages and limitations. Currently, actuators fabricated using thin-film and fiber structures typically have the advantage of simple structure, but their operability is poor and their motion patterns are limited, failing to meet diverse practical application needs. Therefore, to achieve multi-dimensional, multi-form, and controllable flexible motion, it is necessary to design and fabricate new humidity actuators. Summary of the Invention

[0006] To address the technical problem of existing humidity actuators having a single motion mode, this invention provides a humidity actuator based on controllable motion modes of fabric. This humidity actuator can achieve multiple motion modes, exhibiting warping, bending, and curling with controllable curvature and direction, as well as helical twisting with controllable chirality and pitch.

[0007] The specific technical solution of this invention is as follows: A humidity actuator based on controllable motion of a fabric body includes: Humidity-sensitive substrate; the humidity-sensitive substrate is a flexible fabric. A humidity-insensitive coating layer; the humidity-insensitive coating layer is a flexible material; the humidity-insensitive coating layer is deposited on one or both sides of a humidity-sensitive substrate to form a pattern, and partially covers the surface of the fibrous material in the humidity-sensitive substrate; the humidity expansion coefficient of the flexible fabric is at least one order of magnitude higher than that of the flexible material; The humidity actuator, under different humidity-sensitive substrate weaving structures, different humidity-sensitive substrate cutting angles, and different humidity-insensitive covering layer pattern structures, has different operating modes including warping, bending, curling, and spiral twisting, and has different curvature and direction of warping, bending, and curling, as well as different chirality and pitch of spiral twisting.

[0008] The humidity actuator of this invention employs a composite structure of a humidity-sensitive substrate and a humidity-insensitive coating layer, both made of flexible fabric and flexible material, respectively. The humidity-insensitive coating layer is deposited on the surface of the humidity-sensitive substrate to form a pattern and partially encapsulates the fibers within the substrate. In this unique structure, the weaving structure and cutting angle of the flexible fabric affect its movement under humidity stimulation. Simultaneously, the humidity-insensitive coating layer restricts the movement of the flexible fabric under humidity stimulation. Therefore, its pattern structure influences the movement of the flexible fabric under humidity stimulation (the humidity-insensitive coating layer partially encapsulates the fibers in the humidity-sensitive substrate, enabling the fibers to form a double-layer composite structure with asymmetry, thus deforming upon moisture absorption and expansion, leading to various possible movement patterns). In this way, controllable warping, bending, curling, and helical twisting can be achieved, along with adjustable curvature magnitude and direction of warping, bending, and curling, and chirality and pitch of helical twisting, making the humidity actuator capable of exhibiting more diverse movement patterns. Furthermore, the humidity actuator of the present invention can be prepared by a simple method, has flexible and highly controllable motion, and is easy to operate.

[0009] Preferably, the humidity-sensitive substrate is made by first processing textile fibers into warp and weft yarns, and then weaving the warp and weft yarns together in a cross-weave pattern.

[0010] Preferably, the motion mode control method of the humidity actuator includes one or more of the following methods one through three: Method 1: By adjusting whether the warp and weft yarns in the humidity-sensitive substrate are twisted, the movement of the humidity actuator can be controlled to be warping, bending, or curling, and the bending form (such as edge bending or diagonal bending) and the curvature of warping, bending, and curling can be controlled. Method 2: By adjusting the cutting angle of the humidity-sensitive substrate, the movement of the humidity actuator can be controlled to be bending, curling, or spiral twisting, and the chirality and pitch of the spiral twisting can be controlled. Method 3: By adjusting the angle between the warp and weft yarns in the humidity-sensitive substrate, the movement of the humidity actuator can be controlled to be bending, curling, or spiral twisting, and the curvature of bending and curling, as well as the chirality and pitch of spiral twisting can be controlled.

[0011] Furthermore, the first method is as follows: In a humidity-sensitive substrate, where the warp and weft yarns are perpendicular to each other and the cutting angle is perpendicular to either the warp or weft yarn: (1.1) If both the warp and weft yarns in the humidity-sensitive substrate are untwisted parallel yarns, then the motion of the humidity actuator will be such that the curvature is not less than 1cm. -1 The bending or curling; (1.2) If both the warp and weft yarns in the humidity-sensitive substrate are twisted spiral yarns, then the motion mode of the humidity actuator is a curvature of less than 1cm. -1 Warping or bending; (1.3) In a humidity-sensitive substrate, one of the warp and weft yarns is an untwisted parallel yarn, and the other is a twisted spiral yarn. Therefore, the motion of the humidity actuator should have a curvature of not less than 1 cm. -1 The bending or curling.

[0012] Furthermore, the twist coefficient of the twisted spiral yarn is 300-400.

[0013] Furthermore, the second method is as follows: In a humidity-sensitive substrate, where both the warp and weft yarns are untwisted parallel yarns, or one is an untwisted parallel yarn and the other is a twisted spiral yarn, and the warp and weft yarns are perpendicular to each other: (2.1) If the cutting angle of the humidity-sensitive substrate is controlled to be the same as that of the warp or weft yarn, then the motion of the humidity actuator will be bending or curling. (2.2) In a humidity-sensitive substrate, the weft yarn and the warp yarn are respectively the x-axis and y-axis, and the origin of the coordinate axis is on the cutting line. If the cutting line is controlled to be located in the first and third quadrants, the motion of the humidity actuator is a right-hand helical twist. The pitch of the helical twist is controlled by adjusting the angle between the cutting line and the x-axis. (2.3) In the humidity-sensitive substrate, the weft yarn and the warp yarn are respectively the x-axis and y-axis, and the origin of the coordinate axis is on the cutting line. If the cutting line is controlled to be located in the second and fourth quadrants, the motion mode of the humidity actuator is left-handed spiral twisting. The pitch of the spiral twisting is controlled by adjusting the angle between the cutting line and the x-axis.

[0014] Furthermore, the third method is as follows: In a humidity-sensitive substrate, both the warp and weft yarns are untwisted parallel yarns, or one is an untwisted parallel yarn and the other is a twisted spiral yarn. The warp and weft yarns are perpendicular to each other, and the cutting angle is perpendicular to either the warp or weft yarns. In the case where the humidity-insensitive covering layer has a striped pattern: (3.1) If the stripes of the humidity-insensitive coating are perpendicular to the weft yarns in the humidity-sensitive substrate, then the motion of the humidity actuator will be such that the curvature is less than 1 cm. -1 The bending or curling; (3.2) Taking the weft yarn and warp yarn in the humidity-sensitive substrate as the x-axis and y-axis respectively, with the origin of the coordinate axis on the stripes of the humidity-insensitive coating layer, and controlling the stripes to be located in the first and third quadrants, the motion mode of the humidity actuator is left-handed spiral twisting. (3.3) If the stripes of the humidity-insensitive covering layer are parallel to the weft yarns in the humidity-sensitive substrate, then the motion of the humidity actuator will be such that the curvature is not less than 1 cm. -1 The bending or curling; (3.4) Taking the weft yarn and warp yarn in the humidity-sensitive substrate as the x-axis and y-axis respectively, with the origin of the coordinate axis on the stripes of the humidity-insensitive coating layer, and controlling the stripes to be located in the second and fourth quadrants, the motion mode of the humidity actuator is a right-hand spiral twist.

[0015] The above-described methods one through three are examples of several specific ways in which the humidity actuator of the present invention achieves motion mode control. Using these methods, various motion modes can be achieved through structured and patterned control of the humidity actuator, including warping, bending, and curling with different curvatures and directions, as well as helical twisting with different chirality and pitch.

[0016] Preferably, the coefficient of humidity expansion of the flexible fabric is greater than 1×10⁻⁶. -3 / %RH, the coefficient of hygroscopic expansion of the flexible material is less than 1×10⁻⁶. -4 / %RH.

[0017] Preferably, the humidity-sensitive substrate has an equilibrium moisture regain of 10-30% at a temperature of 25°C and a humidity of 95%.

[0018] Preferably, the humidity-sensitive substrate is composed of one or more of the following: raw cotton fiber, silk, wool, hemp fiber, viscose fiber, acetate fiber, and cuprammonium fiber.

[0019] Preferably, the diameter of the textile fiber is 10-20 micrometers, the diameter of the warp and weft yarns is 100-300 micrometers, and the thickness of the humidity-sensitive substrate is 100-200 micrometers.

[0020] Preferably, the area of ​​the humidity-insensitive coating layer on the fiber surface in the humidity-sensitive substrate accounts for 20-80% of the fiber area.

[0021] Preferably, the humidity-insensitive coating layer is a flexible inorganic coating film with a thickness of 100-300 nanometers.

[0022] Preferably, the material of the flexible inorganic coating film is one or more of gold, platinum, aluminum, aluminum oxide, zinc oxide, silicon nitride, and aluminum nitride.

[0023] Preferably, the method for preparing the flexible inorganic coating film includes the following steps: after drying the humidity-sensitive substrate, a film is deposited on the surface of the humidity-sensitive substrate by magnetron sputtering or thermal evaporation to form a flexible inorganic coating film.

[0024] Compared with the prior art, the present invention has the following advantages: The humidity actuator of the present invention adopts a specific double-layer composite structure, which can realize a variety of motion forms, exhibiting warping, bending and curling with controllable curvature magnitude and positive and negative (direction), as well as helical twisting with controllable chirality and pitch. Moreover, the humidity actuator is simple to manufacture, has flexible motion forms with strong controllability, and is easy to operate. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a multi-stage structural model and motion form of the humidity actuator of the present invention.

[0026] Figure 2 These are schematic diagrams and photographs of different weaving methods and movement patterns in Examples 1-3. Figure 2 a is a schematic diagram and photograph of Example 1; Figure 2 b is a schematic diagram and photograph of Example 2; Figure 2 c is a schematic diagram and photograph of Example 3.

[0027] Figure 3 These are schematic diagrams and photographs of different cutting angles and movement patterns in Examples 4-9. Figure 3 a is a schematic diagram of different cutting angles and movement forms; Figure 3 b shows photographs of different motion patterns in Examples 4-9.

[0028] Figure 4These are schematic diagrams and photographs of different pattern coatings and motion patterns in Examples 10-13. Figure 4 a is a schematic diagram of different patterned coatings; Figure 4 b is a photograph of different pattern coatings and motion patterns in Examples 10-13. Detailed Implementation

[0029] To better illustrate the technical content of this invention, the invention will be further described below with reference to embodiments. However, this invention can still be implemented through various other different embodiments; therefore, the scope of protection of this invention is not limited to the embodiments described herein.

[0030] General Implementation Examples A humidity actuator based on controllable motion of a fabric body includes: Humidity-sensitive substrate; the humidity-sensitive substrate is a flexible fabric. A humidity-insensitive coating layer; the humidity-insensitive coating layer is a flexible material; the humidity-insensitive coating layer is deposited on one or both sides of a humidity-sensitive substrate to form a pattern, and partially covers the surface of the fibrous material in the humidity-sensitive substrate; the humidity expansion coefficient of the flexible fabric is at least one order of magnitude higher than that of the flexible material; The humidity actuator, under different humidity-sensitive substrate weaving structures, different humidity-sensitive substrate cutting angles, and different humidity-insensitive covering layer pattern structures, has different operating modes including warping, bending, curling, and spiral twisting, and has different curvature and direction of warping, bending, and curling, as well as different chirality and pitch of spiral twisting.

[0031] In one specific embodiment, the coefficient of humidity expansion of the flexible fabric is greater than 1×10⁻⁶. -3 / %RH, the coefficient of hygroscopic expansion of the flexible material is less than 1×10⁻⁶. -4 / %RH.

[0032] In one specific embodiment, the humidity-insensitive coating layer covers 20-80% of the fiber area on the fiber surface in the humidity-sensitive substrate.

[0033] In one specific embodiment, the humidity-sensitive substrate is made by first processing textile fibers into warp and weft yarns, and then weaving the warp and weft yarns together in a cross-weave pattern; the diameter of the textile fibers is 10-20 micrometers, the diameter of the warp and weft yarns is 100-300 micrometers, and the thickness of the humidity-sensitive substrate is 100-200 micrometers.

[0034] In one specific embodiment, the humidity-sensitive substrate has an equilibrium moisture regain of 10-30% at a temperature of 25°C and a humidity of 95%; the humidity-sensitive substrate is composed of one or more of the following: raw cotton fiber, silk, wool, hemp fiber, viscose fiber, acetate fiber, and cuprammonium fiber.

[0035] In one specific embodiment, the humidity-insensitive coating layer is a flexible inorganic coating film with a thickness of 100-300 nanometers; the material of the flexible inorganic coating film is one or more of gold, platinum, aluminum, aluminum oxide, zinc oxide, silicon nitride, and aluminum nitride; the preparation method of the flexible inorganic coating film includes the following steps: after drying the humidity-sensitive substrate, a film is deposited on the surface of the humidity-sensitive substrate by magnetron sputtering or thermal evaporation to form a flexible inorganic coating film.

[0036] As one specific implementation, the motion mode control method of the humidity actuator is as follows (Method 1): by adjusting whether the warp and weft yarns in the humidity-sensitive substrate are twisted, the motion mode of the humidity actuator is controlled to be warping, bending or curling, and the bending form, as well as the curvature of warping, bending and curling are controlled.

[0037] Alternatively, the above method one is as follows: In a humidity-sensitive substrate, where the warp and weft yarns are perpendicular to each other and the cutting angle is perpendicular to either the warp or weft yarn: (1.1) If both the warp and weft yarns in the humidity-sensitive substrate are untwisted parallel yarns, then the motion of the humidity actuator will be such that the curvature is not less than 1cm. -1 The bending or curling; (1.2) If both the warp and weft yarns in the humidity-sensitive substrate are twisted spiral yarns, then the motion mode of the humidity actuator is a curvature of less than 1cm. -1 Warping or bending; (1.3) In a humidity-sensitive substrate, one of the warp and weft yarns is an untwisted parallel yarn, and the other is a twisted spiral yarn. Therefore, the motion of the humidity actuator should have a curvature of not less than 1 cm. -1 The bending or curling.

[0038] Optionally, the twist coefficient of the twisted spiral yarn is 300-400.

[0039] As one specific implementation, the motion mode control method of the humidity actuator is as follows (Method 2): by adjusting the cutting angle of the humidity-sensitive substrate, the motion mode of the humidity actuator is controlled to be bending, curling or spiral twisting, and the chirality and pitch of the spiral twisting are controlled.

[0040] Alternatively, the second method described above is as follows: In a humidity-sensitive substrate, where both the warp and weft yarns are untwisted parallel yarns, or one is an untwisted parallel yarn and the other is a twisted spiral yarn, and the warp and weft yarns are perpendicular to each other: (2.1) If the cutting angle of the humidity-sensitive substrate is perpendicular to the warp or weft yarn, the motion of the humidity actuator will be bending or curling. (2.2) In a humidity-sensitive substrate, the weft yarn and the warp yarn are respectively the x-axis and y-axis, and the origin of the coordinate axis is on the cutting line. If the cutting line is controlled to be located in the first and third quadrants, the motion of the humidity actuator is a right-hand helical twist. The pitch of the helical twist is controlled by adjusting the angle between the cutting line and the x-axis. (2.3) In the humidity-sensitive substrate, the weft yarn and the warp yarn are respectively the x-axis and y-axis, and the origin of the coordinate axis is on the cutting line. If the cutting line is controlled to be located in the second and fourth quadrants, the motion mode of the humidity actuator is left-handed spiral twisting. The pitch of the spiral twisting is controlled by adjusting the angle between the cutting line and the x-axis.

[0041] As one specific implementation, the motion mode control method of the humidity actuator is as follows (Method 3): by adjusting the angle between the warp and weft yarns in the humidity-sensitive substrate, the motion mode of the humidity actuator is controlled to be bending, curling or spiral twisting, and the curvature of bending and curling, as well as the chirality and pitch of spiral twisting are controlled.

[0042] Alternatively, the third method described above is as follows: In a humidity-sensitive substrate, both the warp and weft yarns are untwisted parallel yarns, or one is an untwisted parallel yarn and the other is a twisted spiral yarn. The warp and weft yarns are perpendicular to each other, and the cutting angle is perpendicular to either the warp or weft yarns. In the case where the humidity-insensitive covering layer has a striped pattern: (3.1) If the stripes of the humidity-insensitive coating are perpendicular to the weft yarns in the humidity-sensitive substrate, then the motion of the humidity actuator will be such that the curvature is less than 1 cm. -1 The bending or curling; (3.2) Taking the weft yarn and warp yarn in the humidity-sensitive substrate as the x-axis and y-axis respectively, with the origin of the coordinate axis on the stripes of the humidity-insensitive coating layer, and controlling the stripes to be located in the first and third quadrants, the motion mode of the humidity actuator is left-handed spiral twisting. (3.3) If the stripes of the humidity-insensitive covering layer are parallel to the weft yarns in the humidity-sensitive substrate, then the motion of the humidity actuator will be such that the curvature is not less than 1 cm. -1 The bending or curling; (3.4) Taking the weft yarn and warp yarn in the humidity-sensitive substrate as the x-axis and y-axis respectively, with the origin of the coordinate axis on the stripes of the humidity-insensitive coating layer, and controlling the stripes to be located in the second and fourth quadrants, the motion mode of the humidity actuator is a right-hand spiral twist.

[0043] Figure 1 The invention demonstrates a structure of a humidity actuator, its fabrication process, and its motion under humidity stimulation, including a flexible fabric body → applying a flexible inorganic coating film to the flexible fabric body → cutting → motion under humidity stimulation.

[0044] Examples 1-3: Regulation of the motion pattern of a humidity actuator by the braided structure of a humidity-sensitive substrate The humidity actuators in Examples 1-3 all have the following structure: The humidity actuator consists of a humidity-sensitive substrate and a humidity-insensitive covering layer. The humidity-sensitive substrate is a silk fabric with moisture-absorbing and expanding capabilities, and its humidity expansion coefficient is 3 × 10⁻⁶. -3 The equilibrium moisture regain is 11% at 25°C and 95% humidity. This mulberry silk fabric has a plain weave structure, where textile fibers are first processed into warp and weft yarns, which are then woven together in a cross-weave pattern. The diameter of the textile fibers is 10 micrometers, the diameter of the warp and weft yarns is 150 micrometers, the fabric thickness is 100 micrometers, and the areal density is 70 g / m³. 2 The warp and weft yarns are perpendicular to each other at a 90° angle. The humidity-insensitive coating layer is a flexible inorganic coating film made of gold-plated material, with a humidity expansion coefficient of 5×10⁻⁶. -5 A 200 nm thick gold film, covering one side of the silk fabric with a relative humidity of 60% RH, partially coats the textile fibers beneath, covering approximately 50% of the fiber area. The humidity-insensitive coating is prepared as follows: After drying the silk fabric at 100°C for 2 hours, a thin gold film is deposited on one side of the silk fabric using magnetron sputtering. The humidity actuator is cut into a square, with two sides parallel to the warp and weft yarns, respectively.

[0045] In the humidity actuator of Example 1, the warp and weft yarns of the silk fabric are the same untwisted parallel yarns. In the humidity actuator of Example 2, the warp and weft yarns of the silk fabric are the same cylindrical twisted spiral yarns with a twist factor of 300. In the humidity actuator of Example 3, the warp yarns of the silk fabric are cylindrical twisted spiral yarns with a twist factor of 350, and the weft yarns are untwisted parallel yarns.

[0046] The motion patterns of the humidity actuators in Examples 1-3 under humidity stimulation are as follows: Figure 2 As shown. From Figure 2 It can be seen that when both the warp and weft yarns are untwisted parallel yarns, the movement of the humidity sensor after absorbing moisture is a high-curvature diagonal curl, with a curvature of approximately 2cm. -1When both warp and weft yarns are cylindrical twisted spiral yarns, the movement of the humidity sensor after absorbing moisture is a low-curvature warp, with a curvature of approximately 0.8 cm. -1 When the warp and weft yarns are cylindrical twisted spiral yarns and untwisted parallel yarns, respectively, the movement of the humidity sensor after absorbing moisture is a high-curvature edge curl, with a curvature of approximately 4cm. -1 .

[0047] Examples 4-9: Control of Motion Pattern by the Cutting Angle of the Humidity Actuator The humidity actuators in Examples 4-9 all have the following structure: The humidity actuator consists of a humidity-sensitive substrate and a humidity-insensitive covering layer. The humidity-sensitive substrate is a silk fabric with moisture-absorbing and expanding capabilities, and its humidity expansion coefficient is 3 × 10⁻⁶. -3 The equilibrium moisture regain is 11% at 25°C and 95% humidity. This mulberry silk fabric has a plain weave structure, where textile fibers are first processed into warp and weft yarns, which are then woven together in a cross-weave pattern. The diameter of the textile fibers is 10 micrometers, the diameter of the warp and weft yarns is 150 micrometers, the fabric thickness is 100 micrometers, and the areal density is 70 g / m³. 2 The warp and weft yarns are perpendicular to each other at a 90° angle. The warp yarn is a cylindrical twisted spiral yarn with a twist coefficient of 350, and the weft yarn is an untwisted parallel yarn. The humidity-insensitive coating layer is a flexible inorganic coating film made of gold-plated material with a humidity expansion coefficient of 5×10⁻⁶. -5 A 200 nm thick gold film, covering one side of the mulberry silk fabric with a relative humidity of 10% RH, partially coats the textile fibers beneath it, with a coating area of ​​approximately 50% of the fiber area. The preparation method for this humidity-insensitive coating is as follows: After drying the mulberry silk fabric at 100°C for 2 hours, a thin gold film is deposited on one side of the mulberry silk fabric by magnetron sputtering.

[0048] The humidity actuators in Examples 4-9 are all cut into rectangles. In Example 4, the cutting line (the long side of the rectangle) is parallel to the weft yarn (i.e.,...). Figure 3 In b, "Θ=0°" belongs to Figure 3 (The case shown in "0°" in section a). In Example 8, the cutting line (the long side of the rectangle) is perpendicular to the weft yarn (i.e., Figure 3 In b, "Θ=90°" belongs to... Figure 3 (The case shown in "90°" in section a). Taking the weft yarns and warp yarns in the silk fabric as the x-axis and y-axis respectively, when the cutting line (the long side of the rectangle) passes through the origin of the coordinate axes: the cutting lines (the long side of the rectangle) in Examples 5-7 are all located in the first and third quadrants, with angles of 30°, 45°, and 60° with the x-axis respectively (i.e., respectively). Figure 3 In b, "Θ=30°", "Θ=45°", and "Θ=60°" all belong to Figure 3 (The case shown in "0-90°" in section a); In Example 9, the cutting lines (the long sides of the rectangle) are all located in the second and fourth quadrants, and the angle between them and the x-axis is 135° (i.e., Figure 3 In b, "Θ=135°" all belong to Figure 3 (The case shown in "90-180°" in section a).

[0049] The motion patterns of the humidity actuators in Examples 4-9 under humidity stimulation are as follows: Figure 3 As shown. From Figure 3 It can be seen that when the cutting line (the long side of the rectangle) is parallel or perpendicular to the weft yarn, the motion of the humidity actuator after absorbing moisture is bending or curling; when the cutting line (the long side of the rectangle) is located in the first and third quadrants, the motion of the humidity actuator after absorbing moisture is a right-handed spiral twist, and the larger the angle between the cutting line and the x-axis, the larger the pitch of the spiral twist; when the cutting line (the long side of the rectangle) is located in the second and fourth quadrants, the motion of the humidity actuator after absorbing moisture is a left-handed spiral twist.

[0050] Examples 10-13: Regulation of Humidity Actuator Motion Pattern by the Graphical Structure of the Humidity-Insensitive Coating Layer The humidity actuators in Examples 10-13 all have the following structure: The humidity actuator consists of a humidity-sensitive substrate and a humidity-insensitive covering layer. The humidity-sensitive substrate is a silk fabric with moisture-absorbing and expanding capabilities, and its humidity expansion coefficient is 3 × 10⁻⁶. -3 The equilibrium moisture regain is 11% at 25°C and 95% humidity. This mulberry silk fabric employs a plain weave structure, where textile fibers are first processed into warp and weft yarns, which are then woven together in a cross-weave pattern. The diameter of the textile fibers is 10 micrometers, the diameter of the warp and weft yarns is 100 micrometers, the fabric thickness is 100 micrometers, and the areal density is 70 g / m³. 2 The warp and weft yarns are perpendicular to each other at a 90° angle. The warp yarn is a cylindrical twisted spiral yarn with a twist coefficient of 350, and the weft yarn is an untwisted parallel yarn. The humidity-insensitive coating layer is a flexible inorganic coating film with a certain striped pattern structure made of gold-plated material, and its humidity expansion coefficient is 5×10. -5A moisture-insensitive coating, with a thickness of 200 nanometers and a RH of 6%, partially coats the textile fibers of the underlying silk fabric, covering approximately 50% of the fiber area. The preparation method of the moisture-insensitive coating is as follows: After drying the silk fabric at 100°C for 2 hours, a mask with a specific pattern is placed over the silk fabric. A thin gold film is then deposited on one side of the silk fabric using magnetron sputtering. The moisture actuator is cut into a rectangle, with its long side parallel to the weft yarn.

[0051] In the striped flexible inorganic coating film of Example 10, the stripes are perpendicular to the weft yarns in the mulberry silk fabric (i.e., Figure 4 (0° in the text). In the striped flexible inorganic coating film of Example 12, the stripes are parallel to the weft yarns in the mulberry silk fabric (i.e., Figure 4 (90° in the original text). Taking the weft and warp yarns in the silk fabric as the x-axis and y-axis respectively, when the stripes pass through the origin of the coordinate axes: In the striped flexible inorganic coating film of Example 11, the stripes are located in the first and third quadrants, and the angle with the x-axis is 45° (i.e., 90°). Figure 4 The "45°" in Example 13; in the striped flexible inorganic coating film, the stripes are located in the second and fourth quadrants, and the angle with the x-axis is 135° (i.e., Figure 4 (135° in the text).

[0052] The motion patterns of the humidity actuators in Examples 10-13 under humidity stimulation are as follows: Figure 4 As shown. From Figure 4 It can be seen that when the pattern stripes of the humidity-insensitive coating are perpendicular to the weft yarns in the humidity-sensitive substrate, the movement of the humidity actuator after absorbing moisture is a low-curvature curl. Figure 4 The curvature in photo b is 0.8cm. -1 When the pattern stripes are parallel to the weft yarn, the motion is a high-curvature curl. Figure 4 The curvature in photo b is 3cm. -1 When the pattern stripes are in the first and third quadrants, the motion is a left-handed spiral twist; when the pattern stripes are in the second and fourth quadrants, the motion is a right-handed spiral twist.

[0053] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A humidity actuator based on controllable motion of a fabric, characterized in that, include: Humidity-sensitive substrate; The humidity-sensitive substrate is a flexible fabric. Moisture-insensitive coating; The humidity-insensitive coating layer is made of a flexible material; The humidity-insensitive coating layer is deposited on one or both sides of the humidity-sensitive substrate to form a pattern and partially covers the surface of the fibrous material in the humidity-sensitive substrate; the humidity expansion coefficient of the flexible fabric is at least one order of magnitude higher than that of the flexible material. The humidity actuator exhibits different operating modes, including warping, bending, curling, and spiral twisting, under different humidity-sensitive substrate weaving structures, different humidity-sensitive substrate cutting angles, and different humidity-insensitive covering layer pattern structures. It also has different curvatures and directions of warping, bending, and curling, as well as different chirality and pitch of spiral twisting. The motion mode control method includes: controlling the motion mode of the humidity actuator to warping, bending, or curling by adjusting whether the warp and weft yarns in the humidity-sensitive substrate are twisted, and controlling the bending form, as well as the curvature of warping, bending, and curling.

2. The humidity actuator as described in claim 1, characterized in that, The humidity-sensitive substrate is made by first processing textile fibers into warp and weft yarns, and then weaving the warp and weft yarns together in a cross-weave pattern.

3. The humidity actuator as described in claim 1, characterized in that, The specific methods for controlling the motion pattern are as follows: In a humidity-sensitive substrate, where the warp and weft yarns are perpendicular to each other, and the cutting angle is perpendicular to either the warp or weft yarn: (1.1) If both the warp and weft yarns in the humidity-sensitive substrate are untwisted parallel yarns, then the motion of the humidity actuator will be such that the curvature is not less than 1 cm. -1 The bending or curling; (1.2) If both the warp and weft yarns in the humidity-sensitive substrate are twisted spiral yarns, then the motion mode of the humidity actuator is a curvature of less than 1 cm. -1 Warping or bending; (1.3) In the humidity-sensitive substrate, one of the warp and weft yarns is an untwisted parallel yarn and the other is a twisted spiral yarn. Then the motion mode of the humidity actuator is a curvature of not less than 1 cm. -1 The bending or curling.

4. The humidity actuator as described in claim 1, characterized in that, The flexible fabric has a humidity expansion coefficient greater than 1×10⁻⁶. -3 The coefficient of hygroscopic expansion of the flexible material is less than 1×10⁻⁶ %RH. -4 / %RH.

5. The humidity actuator as described in claim 1, characterized in that, The humidity-sensitive substrate has an equilibrium moisture regain of 10-30% at a temperature of 25°C and a humidity of 95%.

6. The humidity actuator as described in claim 2, characterized in that, The textile fibers have a diameter of 10-20 micrometers, the warp and weft yarns have a diameter of 100-300 micrometers, and the moisture-sensitive substrate has a thickness of 100-200 micrometers.

7. The humidity actuator as claimed in claim 1, characterized in that, The humidity-insensitive coating layer is a flexible inorganic coating film with a thickness of 100-300 nanometers.

8. A humidity actuator based on controllable motion of a fabric, characterized in that, include: Humidity-sensitive substrate; The humidity-sensitive substrate is a flexible fabric. Moisture-insensitive coating; The humidity-insensitive coating layer is made of a flexible material; The humidity-insensitive coating layer is deposited on one or both sides of the humidity-sensitive substrate to form a pattern and partially covers the surface of the fibrous material in the humidity-sensitive substrate; the humidity expansion coefficient of the flexible fabric is at least one order of magnitude higher than that of the flexible material. The humidity actuator, under different humidity-sensitive substrate weave structures, different humidity-sensitive substrate cutting angles, and different humidity-insensitive covering layer pattern structures, has different operating modes, including warping, bending, curling, and spiral twisting. It also has different curvatures and directions of warping, bending, and curling, as well as different chirality and pitch of spiral twisting. The motion mode control method includes: by adjusting the cutting angle of the humidity-sensitive substrate, controlling the motion mode of the humidity actuator to be bending, curling, or spiral twisting, and controlling the chirality and pitch of spiral twisting.

9. The humidity actuator as claimed in claim 8, characterized in that, The specific methods for controlling the motion pattern are as follows: In a humidity-sensitive substrate, where both the warp and weft yarns are untwisted parallel yarns, or one is an untwisted parallel yarn and the other is a twisted spiral yarn, and the warp and weft yarns are perpendicular to each other: (2.1) If the cutting angle of the humidity-sensitive substrate is perpendicular to the warp or weft yarn, the motion of the humidity actuator will be bending or curling. (2.2) In a humidity-sensitive substrate, the weft yarn and the warp yarn are respectively the x-axis and y-axis, and the origin of the coordinate axis is on the cutting line. If the cutting line is controlled to be located in the first and third quadrants, the motion of the humidity actuator is a right-hand helical twist. The pitch of the helical twist is controlled by adjusting the angle between the cutting line and the x-axis. (2.3) In the humidity-sensitive substrate, the weft yarn and the warp yarn are respectively the x-axis and y-axis, and the origin of the coordinate axis is on the cutting line. If the cutting line is controlled to be located in the second and fourth quadrants, the motion mode of the humidity actuator is left-handed spiral twisting. The pitch of the spiral twisting is controlled by adjusting the angle between the cutting line and the x-axis.

10. A humidity actuator based on controllable motion of a fabric, characterized in that, include: Humidity-sensitive substrate; The humidity-sensitive substrate is a flexible fabric. Moisture-insensitive coating; The humidity-insensitive coating layer is made of a flexible material; The humidity-insensitive coating layer is deposited on one or both sides of the humidity-sensitive substrate to form a pattern and partially covers the surface of the fibrous material in the humidity-sensitive substrate; the humidity expansion coefficient of the flexible fabric is at least one order of magnitude higher than that of the flexible material. The humidity actuator exhibits different operating modes, including warping, bending, curling, and spiral twisting, under different humidity-sensitive substrate weaving structures, different humidity-sensitive substrate cutting angles, and different humidity-insensitive covering layer pattern structures. It also has different curvatures and directions for warping, bending, and curling, as well as different chirality and pitch for spiral twisting. The motion mode control method includes: controlling the motion mode of the humidity actuator to be bending, curling, or spiral twisting by adjusting the angle between the warp and weft yarns in the humidity-sensitive substrate, and controlling the curvature of bending and curling, as well as the chirality and pitch of spiral twisting.

11. The humidity actuator as claimed in claim 10, characterized in that, The specific methods for controlling the motion pattern are as follows: In a humidity-sensitive substrate, both the warp and weft yarns are untwisted parallel yarns, or one is an untwisted parallel yarn and the other is a twisted spiral yarn. The warp and weft yarns are perpendicular to each other, and the cutting angle is perpendicular to either the warp or weft yarns. In the case where the humidity-insensitive covering layer has a striped pattern: (3.1) If the stripes of the humidity-insensitive coating are perpendicular to the weft yarns in the humidity-sensitive substrate, then the motion of the humidity actuator will be such that the curvature is less than 1 cm. -1 The bending or curling; (3.2) Taking the weft yarn and warp yarn in the humidity-sensitive substrate as the x-axis and y-axis respectively, with the origin of the coordinate axis on the stripes of the humidity-insensitive coating layer, and controlling the stripes to be located in the first and third quadrants, the motion mode of the humidity actuator is left-handed spiral twisting. (3.3) If the stripes of the humidity-insensitive coating are parallel to the weft yarns in the humidity-sensitive substrate, then the motion of the humidity actuator will be such that the curvature is not less than 1 cm. -1 The bending or curling; (3.4) Taking the weft yarn and warp yarn in the humidity-sensitive substrate as the x-axis and y-axis respectively, with the origin of the coordinate axis on the stripes of the humidity-insensitive coating layer, and controlling the stripes to be located in the second and fourth quadrants, the motion mode of the humidity actuator is a right-hand spiral twist.

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