Curl actuator system and method

Abstract

A system and method of producing a crimped actuator fiber. The method includes: twisting a fiber to produce a twisted fiber; winding the twisted fiber on the core to produce a roll in the twisted fiber; and removing at least a portion of the core to produce the crimped actuator fiber. In some aspects, the fiber may be a yarn having one or more fibers, or a fiber including a single elongate element. In some aspects, a portion of the core includes a removable sacrificial portion. The removable sacrificial portion may be soluble in a solvent, or may be physically removable. In some aspects, the core further includes an insoluble non-soluble portion, and creating the crimp actuator may include removing the sacrificial portion by treating twisted fibers on the core to remove the sacrificial portion and leave the non-soluble portion.

Description

[0001] This application is a divisional application of the patent application with application number 201880024236.5, application date April 10, 2018, and name “Curling Actuator System and Method”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 483,839, filed on April 10, 2017, entitled “COILED ACTUATOR SYSTEM AND METHOD,” which is hereby incorporated by reference in its entirety and for all purposes.

[0003] This application is also related to PCT application PCT / US2018 / 026941, filed on April 10, 2018, entitled “COILED ACTUATOR SYSTEM AND METHOD” and having agent case number 0105198-019US0, and is also related to U.S. application 15 / 160,439, filed on May 20, 2016, entitled “SYSTEM AND METHOD FOR THERMALLY ADAPTIVE MATERIALS,” which are hereby incorporated by reference in their entirety and for all purposes.

[0004] Government Rights This invention was made with government support under DE-AR0000536 awarded by the U.S. Department of Energy. The government has certain rights in this invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 is a diagram of twisted fibers, filaments or yarns showing the fiber deviation angle (α 纤维 ).

[0006] Figure 2 is a diagram of a twisted and coiled fiber or yarn showing the fiber deviation angle (α 纤维 ), roll angle (α 卷 )、Roll diameter( D ) and fiber diameter ( d ).

[0007] Figure 3a and Figure 3b are illustrations of two example coiled fibers or yarns having different coil bias angles.

[0008] Figure 4a and Figure 4b is an illustration of another example of a twisted fiber or yarn produced by removing a sacrificial layer to increase the distance or spacing between windings.

[0009] Figure 5a and Figure 5b Additional examples of both coiled fibers or yarns produced by winding a twisted fiber or yarn around a mandrel or core material (such as another fiber or yarn), and released coiled fibers or yarns produced after removal of the mandrel or central core material are illustrated.

[0010] Figure 6a and Figure 6b Still further examples of coiled fibers or yarns produced by winding twisted fibers or yarns around a core material including a central core covered with a removable material are illustrated, as well as example coiled fibers or yarns produced after causing the removable material to dissolve or react leaving the central material at the center of the coiled fibers or yarns.

[0011] Figure 7a and Figure 7b Illustrated are examples of twisted fibers or yarns coiled on a mandrel or central core in such a manner that the fibers or yarns are not in contact with their nearest neighbors, and further illustrated are examples of the resulting coiled fibers or yarns after the mandrel or central core is removed.

[0012] Figure 8a and Figure 8b Another example of a twisted fiber or yarn is illustrated, which is curled on a mandrel or center core next to a second fiber or yarn that serves as a spacer for the twisted fiber or yarn, and the curled fiber or yarn produced by removing the mandrel or center core and the spacer fiber or yarn.

[0013] Figure 9a The diagram shows two twisted fibers or yarns coiled around a mandrel or center core.

[0014] Figure 9b Illustration of removing Figure 9a The two curled fiber or yarn actuators produced after the mandrel or center core. The two curled actuators are shown nested within each other.

[0015] Fig.10 An example production process for twisted fibers including process monitoring and feedback is illustrated.

[0016] Fig.11a An example of a fiber take-up system is illustrated that includes a fiber source spool that feeds fiber to an uptake spool that receives and winds the fiber.

[0017] Fig.11b Pictured Fig.11a The fiber crimping system, which Fig.11aIn contrast, the coil nucleation region has propagated towards the take-up spool.

[0018] Fig.11c Picture shows Fig.11a The fiber crimping system, which Fig.11a In contrast, the coil nucleation region has propagated towards the source axis.

[0019] Fig.12a is a graphic representation of a kink or general tangle that can be created in a fiber or yarn by twist insertion.

[0020] Figure 12b is a graphic representation of the cylindrical tangles that can be produced in a fiber or yarn by twist insertion.

[0021] Fig.13 and Fig.14 Two environmentally responsive coiled fiber actuators are shown. Microscope images show coils with similar geometry produced by two different methods. The length of the scale bar is 0.5 mm.

[0022] Fig.15a , Fig.15b , Fig.16a , Fig.16b , Fig.17a , Fig.17b and Fig.18 An example embodiment of a bimorph including one or more coiled fiber actuators is illustrated.

[0023] Fig.19 Presented are graphs with various volume index values ​​( C ) for more than 200 examples of twisted and coiled homochiral fiber actuators.

[0024] It should be noted that the drawings are not drawn to scale, and throughout the drawings, for illustrative purposes, elements of similar structure or function are generally represented by similar reference numerals. It should also be noted that the drawings are intended only to facilitate the description of preferred embodiments. The drawings do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure. DETAILED DESCRIPTION

[0025] In various embodiments, a curling actuator ("artificial muscle") can be created by a twist insertion process. For example, a fiber can be twisted to the point of curling. In another example, the fiber can be twisted almost to the point of curling and then wrapped around a mandrel or fiber or yarn core. Although the various embodiments discussed herein relate to fibers, it should be clear that the various embodiments may include any suitable elongated element, including fibers, filaments, ribbons, yarns, threads, and the like. Additionally, as used herein, "fiber" may encompass any such elongated element, including: a yarn comprising one or more fibers or other elements, a fiber comprising a single elongated element, and the like. Therefore, unless the context dictates otherwise, the term "fiber" should be interpreted as broadly encompassing any such one or more elongated elements.

[0026] In some embodiments, the curled actuator fibers discussed herein can be used to actuate textiles. For example, such textiles can be used to produce clothing that responds to various types of environmental conditions, including temperature, moisture, humidity, and the like. In some embodiments, there may be a minimum load on the textile and / or the textile may need to operate close to body temperature, and various embodiments may be configured to perform desired operations under such operating conditions. Additional embodiments may be configured for various other suitable purposes or applications, and thus the examples involving configurations for use with human or animal users should not be construed as limitations on the numerous applications of the actuators disclosed herein.

[0027] Various embodiments may have numerous advantages for some uses or implementations. For example, some embodiments of the actuator may include greater thermal response values ​​for actuators produced using manufacturing-friendly techniques, wherein the actuator has a controlled coil contact temperature and thermal response range.

[0028] According to various embodiments, the coiled thermal fiber or yarn actuator can be made via the moment of coiling from twisting to twisting or tangling (self-coiling or coiling by twisting), via coiling on a mandrel or other suitable material used as a core around which one or more fibers can be coiled (coiling by winding), or other suitable methods. In various examples, such a core can be partially or fully removable, including removal via dissolution, as discussed in more detail herein.

[0029] In some examples, conventional yarn production machinery (such as spinning or twisting machines) are not able to reliably produce the desired controlled geometry fiber or yarn actuators of the type of curling by twisting. The production of such yarns can be highly sensitive to variables such as ambient temperature and humidity, input filament crystallinity and orientation, friction, defects in the input filaments, variations in spindle speed, feed rate or take-up speed, input filament diameter, yarn tension, etc.

[0030] However, as discussed in more detail herein, in various embodiments, a careful balance between yarn tension, yarn feed rate, number of inserted twists / m, package take-up rate, flyer (or ring and wire traveler) rotation rate during yarn production, and the like can produce a highly twisted or curled actuator with controllable geometry. One or more of these parameters may need to be changed or adjusted during production to account for fluctuations in the above variables; however, some conventional production machines may not allow such parameters to be changed during production. In addition, parameters for one position or spindle may need to be changed in a different manner than parameters in another position or spindle, and some systems may not be able to perform a task if a common drive is used to drive several positions. Therefore, a new machine that provides such functionality is disclosed herein.

[0031] Example methods for inserting twist into filament yarn or fiber (monofilament or multifilament) may include ring twisting, friction spinning, double twisting, and the like. Ring spinning may be a process utilizing the movement of a guide member called a wire ring, which freely circulates around a steel ring to insert twist and simultaneously wind the formed yarn onto a bobbin. In a production environment, a common belt drive system may be used to drive the spindle. The amount of twist inserted into the fiber may be determined by the speed of the yarn disengaged from the feed roller and the rotation rate of the spindle. Due to friction and tension, the rotation speed of the wire ring (also referred to as a follower) lags behind the rotation speed of the spindle. The difference in rotation speed between the wire ring and the spindle may cause the yarn to be wound onto the bobbin. Wing spinning and spun spinning may follow similar principles to ring spinning, in which the wing spindle rotates around a rotating spindle at different speeds, resulting in twist insertion and yarn winding. In double twisting, the twist level can be controlled by setting the yarn feed rate and the spindle rotation speed or the take-up reel rotation speed and the spindle rotation speed. For economic or other purposes, a common belt drive system can be used to drive the motors that control the yarn feed, spindle and / or take-up reel for different positions on the production machine.

[0032] In some embodiments, winding a highly twisted fiber on a mandrel or other core material (such as, another fiber or yarn) can provide a route to a more open coil of a larger diameter with a larger coil spring index value, thereby providing a method for solving thermal response. However, in some examples, winding around a mandrel may not be very suitable for mass production due to the challenge of removing the mandrel from the resulting coiled fiber or yarn actuator. In some examples, if the process includes a short mandrel, it is possible to be tapered at one end, which can be fixed on one side (one or more fibers or yarns are fed to be wound on the mandrel on this side), then the mandrel winding can be more suitable for large-scale manufacturing. When the fiber is coiled around the mandrel and advances, the fiber can fall off from the end of the mandrel and can be wound on a cone or barrel. For a fiber or yarn actuator, in some embodiments, the twisted fiber, fiber or yarn used in the winding or winding process has been shaped (by heating, steam or chemical or mechanical treatment) before winding or winding, and in some embodiments can be shaped after the winding or winding process. In some examples, as described in more detail herein, the sacrificial material can be used as a core during the process of winding or wrapping the fiber or yarn around the sacrificial material, and the sacrificial material can be removed later by physical means, dissolution, melting, washing, chemical methods, etc.

[0033] One approach that can address coil geometry (e.g., thermal response) and / or coil spacing (e.g., active temperature range) can include the use of sacrificial materials. In one such embodiment, a coextruded multicomponent fiber (such as a core-sheath structure, etc.) can be twisted and coiled (e.g., due to twist insertion or by winding on a mandrel or other core material, and optionally the coil actuator can be untwisted) to form a thermal actuator. By dissolving or chemically reacting the sheath so that the sheath is removed, the spring index of the coil can be increased while increasing the coil spacing of some examples. In some examples, the sheath material (or materials) can be removed before or after heat setting.

[0034] Due to the need to rotate the yarn or fiber packaging, some twisting and spinning technologies and machines are limited in their rotation rate. False twist technology can overcome these actual rotation speed limitations by spinning out a smaller mass; however, in various examples, such methods may not insert true twist, and may not allow the production of highly twisted and curled fibers and yarns with desired properties. In some examples, if the imparted twist is released on one side of the fiber or yarn being fed into the twisting machine, the high rotation rate of some false twist technologies can be utilized in the twisting or curling process, so that the other side of the twisting unit can impart true twist, and the twist imparted on the opposite side of the twisting unit may not be simply removed. Twist can be released on the feeding side of the machine by two similar methods. One method is to feed a separate staple fiber into the unit and form yarn at the position of the twisting unit, which is similar to open-end spinning. In various examples, the machine does not need to spin out a large mass and may not have false twist because the yarn can be formed at the rotating position. The second method is to twist the extruded fibers as part of an in-line process where the twist is released due to molecular slip near the extrusion site of the melt, gel or solution.

[0035] Figure 1 An example 100A of a twisted fiber 100 is shown, which shows the fiber bias angle (α 纤维 ). In this example, the twist level in the fiber 100 is represented by the dotted lines 105 twisted on the fiber 100. In various embodiments, the twist level can be directly observed and determined from the fiber 100 by microscopic inspection. Figure 1 As shown in FIG, the fiber deviation angle α can be determined by measuring the angle between the twist observed at the fiber surface and the axial direction of the fiber 100. 纤维 For untwisted fibers, the fiber bias angle will be 0° in various examples.

[0036] During processing and in end-use applications, fibers, filaments, and yarns may be twisted. The fiber and yarn actuators described herein may have so-called "high twist levels" (or "highly twisted"), which in some examples may include sufficient to bring about a fiber deflection angle α of 20° or greater in some embodiments. 纤维 and in other embodiments, the fiber deviation angle α is between 25° and 50°. 纤维 In some examples, "highly twisted" or having a "high twist level" may include producing a fiber bias angle α greater than or equal to 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, or 55°. 纤维The amount of twist in a fiber or yarn. When twist is inserted into a fiber or yarn and the fiber deviation angle increases, the fiber or yarn has a tendency to tangle. The onset of this tangle depends on many variables, including environmental conditions, materials, the material's processing history, and the tension on the fiber or yarn. 纤维 Above 40°, in some cases about 45°, the fibers or yarns often become tangled. 纤维 Highly twisted fibers or yarns between 30° and 40° are advantageous, thereby reducing the likelihood of inducing entanglements while still producing highly twisted filaments that can be used to create coiled fiber actuators by winding around a core material.

[0037] The conditions for producing such highly twisted fibers 100 may vary with environmental conditions, material identity, material processing history, and fiber diameter, with larger diameters in some examples requiring less twist to produce a given fiber bias angle α. 纤维 In the yarn, the effective fiber deviation angle α 纤维 It can be understood as the angle of the filaments at the surface of a twisted or highly twisted yarn.

[0038] For fiber materials like nylon, polyester, etc., the coefficient of thermal expansion (CTE) value can be about 0.05 mm / m / °C in some examples, and no more than about 0.1 mm / m / °C in other examples. In stretched fibers or sheets, the ordering of polymer chains can produce anisotropic properties, and the CTE value can drop ten times or more along the stretching direction in some examples, or become negative in other examples. However, in some examples, the thermomechanical response of the fiber 100 can be effectively amplified by using a coil or spring structure. Commercial fibers and yarns can be coiled or "cylindrically entangled" by inserting high twist levels, thereby producing a coiled fiber thermal actuator according to some embodiments, which can be described as an "artificial muscle", essentially the fiber or yarn has been coiled like a spring so that they have huge or exaggerated thermal expansion properties.

[0039] Figure 2 is a diagram of an example 100B of a twisted and curled fiber 100 showing the fiber bias angle (α 纤维 ), roll angle (α 卷 )、Roll diameter( D ) and fiber diameter ( d ). Figure 1Fiber 100 of the present invention is shown in a coiled configuration that defines a cavity 220 extending within the coiled fiber 100. In this example, adjacent coil portions 240 of the coiled fiber 100 are spaced apart to define a space 260 between the adjacent coil portions 240. For example, a first coil portion 240A and a second coil portion 240B of the coiled fiber 100 define a first space 260A, and a second coil portion 240B and a third coil portion 240C of the coiled fiber 100 define a second space 260B. In this example, the first space 260A and the second space 260B define a continuous space 260 extending within the coiled fiber 100. In additional examples as described in more detail herein, the coil portions 240 of the coiled fiber 100 can be joined such that some or more of the spaces 260 between the portions 240 of the coiled fiber 100 become non-existent (e.g., Figure 3b ).

[0040] The twisted fiber 100 may have a fiber bias angle α 纤维 ,like Figure 1 and Figure 2 In the fiber 100 at the moment of twisting to curling, the fiber deviation angle α can be determined by the material and process conditions used to form the coil. 纤维 However, in some embodiments, this may not result in an optimal or desired fiber bias angle α for a particular target temperature response. 纤维 Roll formation by winding or wrapping around a mandrel or other core may enable the formation of a roll produced from one or more fibers 100 that have been highly twisted to produce a desired fiber bias angle α 纤维 In some embodiments, the desired fiber bias angle α 纤维 It may be between 30° and 50°, and in some examples more preferably between 35° and 45°.

[0041] Roll diameter ( D ) and fiber diameter ( d ) can be used to calculate the coil spring index ( C ). For example, the spring index ( C ) can be defined in spring mechanics as C = D / d ,in d is the fiber diameter and D is the nominal coil diameter as measured through the fiber centerline, as Figure 2 As shown in the figure. With a large spring index ( C ) can be more open, have a larger diameter, and have a small spring index ( C) can more closely resemble a tight coil with a small diameter. Properties such as the effective coefficient of thermal expansion (CTE) and stiffness (e.g., modulus) of the curled actuator can depend on the geometry of the coil (e.g., spring index C and roll angle α 卷 , where the fiber structure also contributes, including the fiber deflection angle α 纤维 In some embodiments, by changing the spring index ( C ), the actuation stroke and / or stress can be tunable to the desired parameters.

[0042] In various embodiments, the thermal response of the coiled fiber 100 may be controlled by the geometry of the coil 100. In some applications, it may be advantageous to maximize the thermal response of the coiled fiber 100, which may require a large coil diameter ( D ) (e.g., relative to the fiber diameter ( d In some examples, the coiled fiber 100 formed without being wound around a mandrel, yarn, fiber, or other core may be limited to a small coil diameter ( D ) and a small coil spring index ( C ) value. In order to break through this limitation of fiber and yarn actuators generated by self-curling to achieve large coil diameter ( D ) and a coil spring index substantially above about 1.7, above 2.0, or above 2.5 ( C ), and an effective coefficient of thermal expansion (CTE) of -2 mm / m / K or greater, the as-spun (as-formed) coils of some embodiments may be untwisted (i.e., twisted in a direction opposite to the direction of twist insertion that caused the coil) to remove excess residual twist and residual compressive mechanical stresses. This untwisting may change the geometry of the coils, increasing their diameter, but in various embodiments need not be performed to the point of coil removal to achieve the desired result. In some embodiments, the maximum coil diameter ( D ) is not achieved by implementing controlled untwisting under a tensile load suitable for the coiling process, but is achieved under a small load (e.g., ≤50% of the load used during the coiling step) or even close to zero load (e.g., ≤10% of the load used during the coiling step, negligible tensile load, etc.). In some embodiments, untwisting can be used to affect the coil spring index (C) and / or geometry of the coil produced by the winding process.

[0043] Roll angle (α 卷 ) can be determined by measuring the angle between the axial direction of the twisted fiber 100 and an imaginary line perpendicular to the direction along which the coiled fiber 100 extends. When the coiled fiber 100 is stretched like a spring, the coil deflection angle (α) 卷) can be increased, and for a given crimped fiber 100, when the crimped fiber 100 is fully compressed to the point where the crimped portions 240 of the fiber 100 contact each other, the crimp deflection angle (α 卷 ) can reach its minimum value.

[0044] In addition to the coil spring index ( C ) (which can reflect the relative fiber diameter ( d ) of the overall roll diameter ( D )) In addition, the roll angle α 卷 may be a measure of the coil structure, which is related to the nature of the coil. When the coil is formed, under the influence of excessive or high twist, the portions 240 of the coiled fiber 100 (coiled by twisting) may be in physical contact with each other, with each coil portion 240 touching its adjacent coil portion 240. Optimal stacking of such coils may result in a coil bias angle α 卷 If the coiled fiber 100 is physically stretched and the coils are pulled apart to create spaces 260 between the coil portions 240, then in some examples the coil bias angle α 卷 The temperature response can be increased and can be decreased.

[0045] Although various coiled fiber actuators that are coiled by twist insertion (a coiling type by twisting) can form a coil with a minimum coil deflection angle α for this size 卷 However, when the roll is formed by winding on a core material (by winding type), in some examples as described herein, there may be a roll bias angle α 卷 Some additional control of the winding angle α is possible because the wound fibers or yarns can be spaced in such a way that the winding angle α 卷 For the coil spring index ( C ) is at its minimum value (adjacent rolls touch each other), or the roll deflection angle α 卷 Greater (with a certain amount of spacing 260 between adjacent roll portions 240). In some applications, it may be advantageous to maximize the thermal response of the actuator, thereby requiring a smaller roll deflection angle α 卷 . Rolling angle α 卷 Control of may also be related to control of the roll-to-roll contact temperature and the environmental response range of the actuator.

[0046] and Figure 1 Likewise, the twist level in fiber 100 is represented by the dotted lines 105 that are twisted on fiber 100. Figure 2 At the bottom of the illustration of FIG. 1 , the twisted fiber 100 is shown in cross section, and the dotted arrows indicate the direction of twist in the twisted fiber 100. Figure 2In the illustrated example of , the twist is in the Z direction, as is the curling, and thus the coiled fiber 100 can be defined as homochiral. Additional examples of coiled fiber 100 can have any suitable chirality. Near the top of the illustration, the fibers or coils are shown by dashed lines as an indication that the fiber 100 coils can continue to have any length. Therefore, in various embodiments, the coiled fiber 100 as discussed herein can have any suitable length. The shaded section of the twisted fiber represents the portion of the coiled fiber 100 that is set back into the illustration page.

[0047] Figure 3a and Figure 3b Two different configurations with different roll angles are shown. Figure 2 Example crimped fiber 100B. Figure 3a The spring index of the curled fiber 100 ( C )and Figure 3b The spring index of the curled fiber 100 ( C ). In various examples, by mechanical stress, by temperature changes that produce expansion, etc. Figure 3b The curled fiber 100B can be stretched to produce a similar Figure 3a Similarly, by mechanical stress, by temperature changes that produce compression, etc., Figure 3a The curled fiber 100B can be compressed to produce a similar Figure 3a In some embodiments, Figure 3a and Figure 3b The example coiled fiber 100 is homochiral, and a decrease in temperature causes a linear expansion of the coiled fiber 100.

[0048] Figure 4a and Figure 4b The use of sacrificial material 410 in controlling the coil geometry of coiled fiber 100 is shown. For example, Figure 4a A core crimped fiber 100 is illustrated having a shell 410 (or islands in the sea), wherein the shell 410 may be a removable material. For example, in some embodiments, the shell 410 may be removable (e.g., via washing, chemical dissolution, etc.), and as Figure 4b As shown in the example of , the resulting curled fiber 100 can have additional spacing between the curls of the fiber 100 and / or have different curl index values. Figure 4b As shown in FIG. 1 , a space 260 may be created between the respective portions 240 of the crimped fiber 100. Figure 4a and Figure 4b The coiled fiber 100 of FIG. 1 does not depict twist in the fiber 100 , but in further embodiments, the coiled fiber 100 may include any suitable amount of twist.

[0049] Figure 5a and Figure 5b The use of a sacrificial core 510 in the control of coil geometry is shown, which shows a twisted fiber 100 wrapped around a core 510, which can define the inner diameter of the coiled fiber 100. The dashed line of the core 510 indicates that the core 510 can have any suitable length. The core 510 can be placed within the cavity 220 of the coiled fiber 100 and can include elements including a mandrel, a filament, a yarn, etc. In various embodiments, the twisted fiber 100 can be removed. Figure 5a 510 (e.g., physically, chemically, or in another suitable manner) to produce Figure 5b In one embodiment, the central core 510 may include a filament or yarn that includes a soluble polymer (such as polyvinyl alcohol, ethylene vinyl alcohol, etc.) that can be dissolved in water or other solvents, including at any suitable temperature (such as room temperature, 40°C, 60°C, 80°C, or higher or lower temperatures).

[0050] For production methods that wrap one or more twisted fibers 100 around a sacrificial core 510, it is not necessary to completely remove the core 510, and in some cases, it may be desirable to retain a portion of the core 510. Leaving a portion of the core 510 in the cavity 220 of the curled actuator fiber 100 can be advantageous in many other ways, including situations where the remaining material is conductive (e.g., metal, composite material, organic material, etc.) and can allow heating of the material, and situations where the material is extensible (e.g., due to its chemical nature, mechanical structure, etc.) allowing for easy linear extension but increasing the strength of the material with respect to bending or flexing.

[0051] As an illustration, a water-soluble fiber may be used as the core 510 in a covered yarn, wherein the covered fiber or fibers are twisted prior to or during the winding that constitutes the core 510 wrap, and the core 510 may be removed by a washing step after setting the wound fiber 100. Many materials are suitable for use as the central sacrificial core 510, such as water-soluble polymer filaments or yarns, organic-soluble polymer filaments or yarns, or filaments or yarns that are easily dissolved or degraded in the presence of acids or bases, oxidizing or reducing agents, or other chemical agents.

[0052] As a non-limiting example, an "island in the sea" yarn can be used as a sacrificial core 510, and when the "sea" component of the yarn is washed away, the fine fiber yarn can remain within the cavity 220 of the coil actuator. These fibers can be used for moisture management or to limit the range of motion of the fiber actuator. In the case of a pure chiral fiber actuator, an effective minimum length can be achieved at the coil contact temperature (i.e., some or all portions 240 of the coiled fibers 100 are in contact, such that the space 260 is partially or completely absent; a pure chiral fiber actuator will have a physical space between its coils at temperatures below the coil contact temperature), but as the temperature drops and the coils expand, the range of motion of the coiled fiber 100 will be limited by the presence of one or more fibers extending through the cavity 220 of the coiled fiber 100. "Islands in the sea" yarns can be made of multi-component extruded fibers, at least one of which can be soluble or otherwise removable, thereby enabling the formation of fine features (including "islands") of non-sacrificial material in a "sea" of sacrificial material. At some point in the process, the sacrificial material may be removed, leaving behind “islands” that may be fibers with fine features that would be difficult to process at high speeds on some machines if they were not protected by the sacrificial “sea” of material.

[0053] For example, Figure 6a and Figure 6b Another example 100E of a coiled fiber 100 is shown, which may be produced by winding a twisted fiber 100 around a core 510 that includes a removable sheath material 610 and an inner material 620. Figure 6a In an example of a core 510, the core 510 may include an outer layer or shell material 510 that may be soluble or otherwise removable, and after the twisted fibers 100 are wound around the core 510, the removable shell material 610 may be dissolved or otherwise removed, thereby allowing the twisted fibers 100 to move freely while leaving a smaller central core inner material 620, such as Figure 6b Although the remaining core material is illustrated as a single material in a single strand, in some embodiments it may include multiple materials and / or multiple strands.

[0054] By controlling the number of twists per meter or wraps around the core 510, the winding spacing of an actuator including one or more coiled fibers 100 produced by winding (including coiled fibers 100 with or without spaces 260 between portions 240 of the coiled fibers 100) can be controlled. For example, Figure 7a Another example 100F of a twisted fiber 100 is illustrated, which is coiled on a core 510 (e.g., a mandrel or central core having one or more materials as discussed herein) in such a manner that each fiber yarn coil portion 240 does not contact the nearest adjacent coil portion 240, thereby creating a space 260 within the coiled fiber 100. Figure 7b When core 510 is removed as shown in FIG. 5 (eg, via dissolution, physical removal, etc.), crimped fibers 100 can become free for unimpeded movement in response to changing environmental conditions (eg, temperature, moisture, etc. as discussed herein).

[0055] The spacing between the coil sections 240 can also be controlled by using spacer fibers 830, such as Figure 8a For example, Figure 8a As shown in example 100G of the invention, the twisted fiber 100 can be coiled on a core 510 (e.g., a mandrel, a mandrel having one or more materials as described herein, or a center core) and can be wound alongside a spacer fiber 830 that serves as a spacer for the twisted fiber 100. The spacer fiber 830 can be positioned between corresponding coil portions 240 and prevent the coil portions 240 from contacting each other. This method can provide a way to control the coil-to-coil spacing in the coiled fiber 100. Figure 8b Shown are the remaining crimped fibers 100 after removal of the spacer fibers 830 and the core 510. As discussed herein, the spacer fibers 830 and the core 510 can be removable in various suitable ways, including dissolution via a solvent, physical removal, and the like.

[0056] Figure 9a A first twisted fiber 1001 and a second twisted fiber 1002 are illustrated coiled on a core 510 (eg, a mandrel), wherein the two twisted fibers 1001 , 1002 are seated beside each other. Figure 9a A structure 900 is shown comprising two fibers 1001, 1002 wound around a removable core 510, and Figure 9b The structure 900 of two nested coiled actuator fibers 1001, 1002 after being released from the core 510 is illustrated. The two fibers 1001, 1002 are illustrated to show the twist, and both coils are shown as homochiral coils. Figure 9a and Figure 9b In the example structure 900, the second fiber 1002 is shown as having a smaller size, which is about 80% of the first fiber 1001. In other examples, the two fibers 1001, 1002 can be the same size, or can be and adapt to different sizes or diameters. In some embodiments, when exposed to changes in environmental conditions (such as, temperature reduction), the two nested coiled fibers 1001, 1002 (in Figure 9a and Figure 9b The structures 900 (shown as being in physical contact with each other in FIG) can expand accordingly, and the linear length of the nested structures 900 can increase. As with other illustrations, a portion of an example actuator is shown, but such fiber or yarn material can have any length.

[0057] Partial or complete removal of the sacrificial core 510 can provide a free coiled fiber actuator on the spool or in-line during the process, but the sacrificial core can also be removed at the fabric or finished product stage. As a non-limiting example, a soluble sacrificial core can be used to coil highly twisted filaments, and the sacrificial core can be removed after knitting or weaving a fabric including a wound structure. In such cases, the sacrificial core can provide dimensional stability and facilitate ease of handling during fabric production and processing.

[0058] The coiled fiber 100 can be manufactured in a variety of suitable ways. For example, a coiling machine can be used to produce coils in a linear fiber 100, as discussed in more detail herein. In some embodiments, such coiling machines can include sensors to monitor the coiling of the fiber 100 and modify the parameters of the coiling machine based on data from such sensors. For example, in some embodiments, it can be advantageous to monitor fiber properties and use real-time information to control production. The output of the sensor can be used in a feedback loop to adjust machine parameters to produce a highly twisted yarn with desired geometric and mechanical properties and minimal failure. One or more portions of the coiling machine can be individually controllable.

[0059] At the moment when the fiber 100 is twisted to coil, it may be desirable to know where the yarn has been coiled along the feed path so that parameters such as yarn tension, yarn feed rate, number of twist insertions / m, package take-up rate, or flyer spindle rotation rate can be adjusted to prevent a malfunction. Examples of malfunctions may include yarn breakage, yarn hooking, or undesirable or uncontrolled entanglement. Some sensors can detect a malfunction (e.g., yarn breakage) and output a signal to stop the machine or alert a technician that a malfunction has occurred.

[0060] An example strategy for producing a coiled fiber 100 with controllable geometry is to determine the twist level along the length of the fiber 100 and adjust the spindle speed, the flyer speed and / or the take-up reel speed to take up the highly twisted (and possibly coiled) yarn onto a bobbin or spool. In some examples, if the twisted or coiled fiber 100 is not properly taken up onto the bobbin, it can cause a malfunction. The twist level along the length of the fiber 100 can be determined by adding one or more sensors along the fiber path 100. The sensor output can be used in a feedback loop to adjust machine parameters to prevent malfunctions and / or produce a coiled fiber 100 with a desired geometry. Such sensors include optical sensors (e.g., CCD or camera systems, encoders, laser micrometers, optical micrometers, laser interferometers, etc.), mechanical sensors (such as, spring-loaded mechanical switches, etc.) and / or electrical sensors (such as, potentiometers, strain sensors, piezoelectric sensors, etc.).

[0061] The geometry of the twisted fiber 100 can be measured during production either directly (e.g., by measuring the diameter of the twisted fiber 100) or indirectly (e.g., by measuring other properties related to the geometry of the twisted fiber 100). The sensor output can be used in a feedback loop to adjust machine parameters (e.g., tension, twist speed, feed rate, take-up rate, etc.) in real time until the desired twist level and geometry are produced.

[0062] Properties that may be related to the twist level and geometry of the active fiber 100 may include, but are not limited to, filament hue / reflectivity, gloss, filament or fiber diameter ( d ), impedance, strain, fiber smoothness or texture, local fiber speed, etc. For example, the speed of a highly twisted area of ​​fiber 100 can be much lower than the speed of an area where low twist levels exist. In some embodiments, if the conductive filament or fiber 100 is twisted, a Hall effect sensor can be used.

[0063] In various embodiments, one or more tension sensors or feeders may be placed along the fiber path, and data from such sensors may be used to control the geometry of the twisted fiber during manufacturing. Highly twisted fiber 100 may experience axial contraction, which in some examples may increase tension in the fiber 100 unless the feed rate is adjusted to compensate for the axial contraction. Sensors and / or associated process control systems that measure roll geometry (either directly or indirectly) may be added to machines that impart false twist, or to machines that impart true twist in the fiber 100.

[0064] The sensor output (such as the size of the fiber 100 at a given location along the fiber path) can be fed back into the process control of the machine and can inform the take-up speed, tension, twist rate, feed rate, or other process variables. In some embodiments, it may be advantageous to consider the output of multiple sensors along the fiber path and / or the output from one or more process measurements, such as fiber size, fiber speed, tension, and environmental conditions (such as temperature and moisture). Some sensors (such as cameras) can provide more than one piece of information, such as an indication of fiber diameter ( d ) and fiber speed.

[0065] As a non-limiting example, the sensor may be used to monitor and control twist levels in the production of highly twisted filaments, yarns or fibers 100. Fiber deflection angle α 纤维 The performance properties of the fiber or yarn actuator can be contributed to, and the twist level in a filament, one or more fibers, or a yarn can be monitored during production and provide information for controlling the twisting process and the resulting fiber deflection angle α. 纤维For example, twist information can be used to change the take-up rate or tension on the fiber. A camera is an example of a sensor that can provide information about the twist level of a filament, which can be measured by determining the fiber diameter ( d ) (Fiber diameter ( d ) can become thicker when twisted), by directly measuring the fiber deflection angle α 纤维 , or by other suitable method.

[0066] In another non-limiting example, sensors can be used to monitor the coiling of the environmentally responsive actuator fiber 100 and can provide information for controlling the production of the coiled fiber 100. For example, a camera or other suitable vision system can provide information about the twist level of the fiber 100 and can be used to monitor the twist level of the fiber 100 before coiling; can be used to monitor the coiling rate or coiling position along the fiber 100, and such information can be used to determine the appropriate take-up rate for the coiled fiber 100 and / or for adjusting the tension. In some embodiments, such a system can determine the coil diameter ( D ), in some examples, the roll diameter ( D ) can be important in the final properties of the fiber 100, and such a system can provide roll diameter information to the machine's control system to increase or decrease tension, which can directly affect the roll diameter ( D ).

[0067] Various information from sensors (either directly monitoring the process or monitoring environmental conditions) can be integrated into the control system of the crimping machine. As a non-limiting example, ambient humidity, temperature measurements, etc. can be correlated with the roll diameter ( D ) to provide information regarding the control of the tension and / or take-up rate of the fiber 100 being processed.

[0068] For example, Fig.101 is a diagram of a production method 1000, which in some embodiments can be monitored and controlled by sensors to automate the process partially or entirely, so that user interaction is not necessary for some or all parts of the method 1000. At 1010, a fiber or yarn from a source is tensioned and fed into a position so that at 1020, the material is twisted at the position. Then, at 1030, the twisted and possibly curled fiber or yarn can be taken up onto a bobbin or spool. The three stages 1010, 1020, 1030 are illustrated in boxes and surrounded by solid lines, and the material transfer from tensioning to twisting to taking up is shown by solid arrows. Process sensors 1040 and environmental sensors 1050 are represented in boxes with dashed edges, and the dashed arrows shown between the various boxes illustrate feedback for controlling the stages 1010, 1020, 1030.

[0069] As an example of how sensors (e.g., sensors 1040, 1050) can affect process conditions and controls, environmental sensors that monitor temperature and moisture can inform the set point of the tension of the fiber, and if the tension becomes too great, the feeder can allow more material to enter the twisting zone. In other words, in some examples, data from one or both of sensors 1040, 1050 can be used to determine and implement the tension setting and / or feed rate of the fiber, which can include increasing or decreasing the tension and / or increasing or decreasing the feed rate. Such feed rates can include feeding from the fiber source and / or feeding to the twisting zone. For example, under some environmental conditions, it may be desirable to increase or decrease the twisting rate, and therefore the temperature and / or relative humidity data from environmental sensor 1050 can inform the twisting rate.

[0070] In some embodiments, sensors (e.g., cameras) monitoring the process 1040 can provide information for controlling the tension 1010 and the take-up rate 1030. As a non-limiting example, the process sensor(s) 1040 can include a vision system (such as a camera) that can be used to monitor the formation of coils in the fiber during the process of the highly twisted fiber being further twisted to induce curling. Before curling, the fiber or yarn can have a certain thickness, which the vision system can view and measure as part of the image analysis through pixel counting or other suitable processes. Twist insertion can change the thickness of the fiber, but curling can significantly change the effective thickness of the fiber, thereby increasing the pixel count across the width of the material.

[0071] If the coil nucleates during the twisting process, additional twist insertion can cause the coil to grow and propagate through the twisted fiber or yarn. Within the field of view of the vision system, image analysis can be used to determine the presence of the coil, and by comparing frames in the video, the speed at which the coil advances or retreats can be determined. When the coiled fiber or yarn is taken up onto a spool or bobbin at 1030, if the take-up rate is too high, the coil may move out of the field of view of the process sensor 1040 (e.g., outside the field of view of the vision system). Alternatively, if the take-up rate is too low, the propagation of the coil may be carried out throughout the field of view of the process sensor 1040, and the coil structure may move backward in the system toward the tension feeder. The backward migration of the coil propagation toward the tension feeder and the forward migration of the coil propagation toward the take-up bobbin may be undesirable. Therefore, information from the process sensor 1040 (e.g., image or video analysis of data from a camera or other vision system) can be used to control the process to keep it stable. In other words, data from process sensors 1040 may be used to control variables such as tension, feed rate, twist rate, take-up rate, etc., to maintain the roll nucleation point at a desired location or within a desired range of locations.

[0072] For example, Fig.11a An example of a fiber take-up system 1100 is illustrated, which includes a fiber source spool 1102 that feeds fiber 100 to a take-up spool 1104 that receives and winds the fiber 100. Note that Fig.11a The configuration of fiber crimping system 1100 is merely an example of one configuration of such fiber crimping system 1100 , and any other suitable fiber sources, fiber take-ups, and tensioning elements are within the scope and spirit of the present disclosure.

[0073] like Fig.11a As further shown in FIG. 1 , the fiber 100 may include a linear portion 1110 that is detached from the source spool 1102 and a coiled portion 1120 that is wound onto the take-up spool 1104. The coil nucleation region 1130 separates the linear portion 1110 and the coiled portion 1120 and is the location where the linear portion 1110 of the fiber 100 becomes the coiled portion 1120 when the fiber moves from the source spool 1102 to the take-up spool 1104. Additionally, Fig.11a A roll nucleation window 1140 is shown, which may be detected by one or more process sensors 1040 (such as Fig.11a The camera 1150 shown in the example system 1100 is used to monitor the volume nucleation window.

[0074] The roll nucleation window 1140 may include a desired location in which the roll nucleation region 1130 should be positioned. When the fiber 100 moves between the source spool 1102 and the take-up spool 1104 and becomes curled at the roll nucleation region 1130 on the fiber 100, the roll nucleation region 1130 may propagate toward the take-up spool 1104 (e.g., as Fig.11b ) and can propagate toward the source spool 1102 (e.g., as Fig.11c ), which can potentially move the roll nucleation region 1130 outside the roll nucleation window 1140 (e.g., as shown in Fig.11b and Fig.11c ). Thus, the system 1100 can monitor the position and movement of the roll nucleation region 1130 via one or more process sensors 1040, and adjust the operating configuration of the system 1100 in real time to maintain the roll nucleation region 1130 within the roll nucleation window 1140 and / or move the roll nucleation region back into the roll nucleation window 1140.

[0075] As an example, if the propagating roll portion 1120 moves toward the take-up bobbin or spool 1104, the take-up rate at the update spool 1104 may be decreased to move the roll nucleation region 1130 toward the source spool 1102. In another example, if the propagating roll portion 1120 moves toward the fiber feeder spool 1102, the take-up rate at the take-up spool 1104 may be increased. By monitoring the speed of the roll nucleation region 1130 rather than just the position of the roll nucleation region 1130, it may be possible to adjust the take-up rate at the take-up spool 1104 based on the propagation rate of the roll nucleation region 1130. However, in other embodiments, sufficient process stability may be achieved by only identifying the position of the propagating roll nucleation region 1130. In some embodiments, the take-up rate at the take-up spool 1104 can be maintained at a constant value, and changes in the position and / or rate of propagation of the roll nucleation region 1130 during production can be fed back to control the twist rate of the fiber 100, which can increase the twist to coil faster, thereby causing the roll nucleation region 1130 to propagate away from the take-up spool 1104 and toward the fiber source spool 1102. In other embodiments, reducing the twist rate of the fiber 100 can reduce the coiling rate and can cause the propagation of the roll nucleation region 1130 to move away from the fiber source spool 1102 and toward the take-up spool 1104.

[0076] As another example, Fig.10 The process sensors 1040 in the production method 1000 illustrated in FIG. 1000 can provide information to the control system to affect the geometry of the crimped fiber 100 produced by the system 1100. As an example, image or video analysis of data from a camera 1150 or the like can be used to determine the geometry of the crimped fiber 100 by reference to the fiber diameter ( d) and roll diameter ( D )(See Figure 1 and Figure 2 ) to determine the coil spring index of the coiled material ( C ), fiber diameter ( d ) and roll diameter ( D ) can be measured in any suitable manner (e.g., by counting pixels across an image or frame of the material during processing). In some embodiments, the coil spring index ( C ) can be a relative measure rather than an absolute measure, so the reference pixel count can be used to determine the coil spring index ( C ) and partially understands a simple way of the geometry of the as-spun coil portion 1120. Therefore, in some examples, calibration may not be required. In various embodiments, if the monitored or determined coil spring index ( C ) is too small or below a defined minimum coil spring index threshold, the tension of the fiber 100 may be reduced. Alternatively, if the monitored or determined coil spring index ( C ) is too large or above a defined maximum coil spring index threshold, the tension in fiber 100 may be increased.

[0077] In some embodiments, it may be desirable to increase the productivity of the twist roll actuator. However, in some examples, high twisting speeds may increase the risk of fibers forming undesirable kinks or general tangles (see Fig.12a ) rather than forming a cylindrical tangle that produces a coil (see Figure 12b In some examples, higher tension on fiber 100 can reduce the likelihood of kinking due to twist instability (forming common tangles), but higher tension can increase the chances of kinking in fibers with smaller spring indices ( C ) to produce a tighter coil in the fiber 100.

[0078] An alternative exemplary approach may be to limit the physical space provided to the twisted fibers 100 so that the fibers 100 do not have the opportunity to experience and form kinks or general entanglements (see Fig.12a ) associated with the physical space required for the deformation associated with the cylindrical entanglement. In some embodiments, both ordinary entanglement and cylindrical entanglement may require the fiber 100 to undergo physical deformation, but the kink or ordinary entanglement may be orthogonal to the stretching direction of the fiber, which in some examples requires more space. By limiting the space provided to entangle the fibers or yarns (e.g., by using a restraining tube, etc.), in some examples, it may be possible to maintain sufficient physical space for cylindrical entanglement to occur while removing the space that would be required to form a kink or ordinary entanglement.

[0079] For example, in some embodiments, the crimper 100 may include a constraining tube through which the fiber 100 extends, wherein the inner diameter of the constraining tube is greater than or equal to the desired crimp diameter (D ) or maximum coil diameter and is less than or equal to the diameter or width of a kink or ordinary tangle that may be alternately produced by the fiber 100.

[0080] As discussed herein, for various embodiments of the actuator, the coil geometry and / or coil spacing can affect the properties of the twisted and curled actuator. However, control of the coil geometry and / or spacing can be achieved in various suitable ways. For example, one approach can be to control the production temperature and / or moisture content during production. Just as in some examples it can be advantageous to utilize different tensile loads during twisting and untwisting, in some examples it can be advantageous to utilize different temperatures (or moisture contents) during the twisting and untwisting steps. Alternatively, it can be advantageous to modify the tension in response to temperature.

[0081] In various embodiments, one or more coiled fibers 100 as discussed herein may define a coiled fiber actuator that may respond to environmental conditions such as temperature, humidity, moisture, etc. For practical use of such coiled fiber actuators, in some embodiments, it may be desirable to control the range or limits of the thermal response (e.g., stroke, ∆length / ∆temperature) and / or the temperature response. For a given fiber material, the magnitude of the thermal response may be affected by the geometry or structure of the coil, including the coil bias angle α. 卷 and roll diameter ( D ) or the openness of the roll (e.g., a larger roll diameter ( D ) can produce a large coil spring index ( C ), and such rolls may have a greater thermal response). Additionally, one end of the temperature response range may be controlled by the spacing of the rolls (e.g., once the roll portions 240 are in contact with each other, contraction of the curl actuator requires compression of the material and may greatly attenuate the magnitude of the thermal response).

[0082] For practical use of curling actuators, in some examples, it may be desirable for such curling actuators to have a desired thermal response (e.g., amount of actuation for a given temperature change, ∆strain / ∆T), and it may be desirable for such curling actuators to respond over a temperature range relevant to the application. In some cases, it may be advantageous to control the range of motion as well as a minimum effective length (e.g., at a particular temperature) and a maximum length (e.g., at another temperature), where actuation occurs effectively only between these two temperatures and two lengths.

[0083] For some embodiments of thermal actuators with negative thermal expansion coefficients, these thermal actuators have fibers and coils twisted in the same direction (e.g., homochiral coils), at and above a certain temperature, the coils can contact each other (coil contact temperature), thereby reaching the effective minimum length of the actuator. In various examples, the homochiral coiled fiber actuator will have physical space between its coils when its temperature is below its coil contact temperature. Artificial muscles can be used in robotic applications, in which they can move mass. In these applications, the initially loaded coiled actuator can stretch the coils of the actuator and can pull them apart, allowing the load to be lifted when the actuator contracts. However, in applications where the actuator is not pre-stretched or pre-loaded, in some embodiments, it may be necessary to actuate the coiled fiber within the temperature range of interest. For applications in clothing and other fields where actuation close to body temperature may be desired, in some examples, the actuator may not reach a compressed state in which the coils are in contact with their neighbors until the temperature exceeds the desired range of activity, thereby allowing movement within the entire range of interest. However, some existing methods for producing coiled actuators produce actuators that require extended cold temperatures (e.g., less than 10°C) when the actuator is unloaded, as they may be in some apparel examples. Controlling the physical spacing between coils and coil contact temperature (where adjacent coils are in contact and have a large response drop to temperature) can be important for producing coiled fiber actuators that are practical for actuating textiles, particularly apparel and bedding.

[0084] In various embodiments, controlling the spacing 260 between the coil portions 240 can be used to control the coil contact temperature, above which some of the coil actuators can be effectively inactive. To increase the spacing 260 between the coil portions 240, the residual excess twist and compressive stress in the as-produced coil can be reduced or removed by untwisting as described above. The coiled fiber actuator can be heat set (e.g., annealed), and the setting conditions can also contribute to the spacing between the coils. The coils can be temperature responsive by design and can respond to large temperatures applied during heat setting, which in some examples can exceed 200° C. depending on the material. In some examples, depending on the specific annealing conditions (e.g., time, temperature, presence of any accelerators such as water, etc.), some amount of residual compressive stress in the material can be removed. In various embodiments, any portion retained or produced by heat setting will affect the coil spacing.

[0085] Heat setting can be performed at various suitable temperatures for various suitable times. For example, in some embodiments, heat setting can be performed at 140°C, 170°C, or 200°C. In other examples, heat setting can be performed at a temperature less than or equal to 150°C, 140°C, or 130°C, etc. In yet another example, heat treatment can be performed at a temperature greater than 100°C, 110°C, 120°C, 130°C, or 140°C. The temperature range for such heat treatment can be within the range between any of these example temperatures. In some examples, the curling actuator can be heat treated within the desired temperature range for various suitable time periods, including 15 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, or 4 hours. Additionally, heat treatment can be performed within a suitable range limited by any of these example time periods.

[0086] For the same heat setting conditions, three non-limiting example cases are described herein. The first example is a case where the fiber actuator is free to move during the setting procedure. The high temperature of the process causes the roll to compress, and the actuator can then be set in this compressed position. Coming out of the heat setting procedure, as the temperature cools, the roll will have a tendency to expand, but in some examples any residual compression may be detrimental to the expansion of the roll, and the rolls can still contact each other at room temperature or a temperature range of interest for the intended application.

[0087] The second example heat setting procedure physically constrains the fiber actuator during the annealing process so that the temperature increase does not physically bring the coils into closer contact with each other. There are many ways to apply such constraints, for example, one embodiment includes winding the fiber actuator onto a spool and constraining the entire batch of fibers during the setting procedure, such as by wrapping the spool with a sheet or tape that can withstand the conditions of the setting procedure. After the setting process, in some embodiments, the cooled actuator coils will have a tendency to expand and separate to a greater extent than the heat-set actuators are free to shrink during the setting process. The coil contact temperature value of the fiber actuator constrained during the heat setting process can be higher than the coil contact temperature value of a similar actuator heat-set without physical constraints, and the higher coil contact temperature can enable the use of an unloaded actuator at room temperature and body temperature or at other desired temperatures. As discussed herein, body temperature may include temperatures including about 37.0°C, 38.0°C, 39.0°C, etc., as well as temperatures typically found at the skin or in the environment surrounding the skin (including about 27.0°C, 28.0°C, 29.0°C, 30.0°C, 31.0°C, 32.0°C, 33.0°C, 34.0°C, 35.0°C, 36.0°C, etc.). As discussed herein, room temperature may include temperatures including about 10.0°C, 15.0°C, 20.0°C, 25.0°C, 30°C, etc.

[0088] The third example heat setting procedure may be similar to the second example in that the third example constrains the fiber actuator during the heat setting process, but it does so by intentionally stretching the actuator during the process. In some embodiments, this may further shift the roll contact temperature to a higher value. For each of these three cases, temperature, time, and the presence of any chemical agents that promote material setting may be additional factors.

[0089] For environmentally responsive twisted and coiled fiber and yarn actuators, in some embodiments, if the setting procedure is modified to shift the coil contact temperature to a higher value, the coil can become more extended at a lower temperature (e.g., a larger coil bias angle α 卷 For some example applications in the field of apparel and textiles, it may be desirable to have a large thermal response (e.g., |CTE| ≥ 2 mm / m / K) and a high coil contact temperature (e.g., 20°C, more preferably 40°C in some cases).

[0090] For curling produced by winding, in some embodiments, untwisting can be used to reduce the roll diameter ( D ) expands and can affect the roll spacing 260. In addition, the spacing 260 between the roll portions 240 of some embodiments can be controlled by winding the twisted active fiber 100 on a mandrel or other core material 510 with some spacing 260 between the roll portions 240 (see Figure 7a ) and / or winding the active fiber 100 sacrificial fiber 830 together on a mandrel or other core material 510 so that the sacrificial fiber 830 acts as a physical spacer between the roll portions 240 (see Figure 8a ). The sacrificial material 830 can be physically removed (e.g., unwound from a coil), dissolved, removed by chemical means, etc. The diameter or size of the sacrificial material can be comparable to the diameter or size of the twisted fiber 100 being coiled, or the sacrificial material 830 can be larger or smaller as a way to control the spacing 260 between coils in the final actuator fiber 100.

[0091] In some embodiments, the coil contact temperature can be used to limit the range of motion of the actuator. In some applications, it may be advantageous to limit the minimum length of the actuator, and by controlling the coil contact temperature, the minimum length can be set to that temperature and any higher temperature. While there will be some variation as the temperature continues to increase in some examples, this variation will be much smaller because the coils are not free to move (this description assumes that the coil actuator expands as the temperature decreases, which is the case for homochiral coils; heterochiral coils, where the coil direction is opposite to the twist direction, may have the opposite behavior and may shrink to a minimum size as the temperature decreases and coil-coil contact is created, and once a coil portion 240 is in direct contact with an adjacent coil portion 240 (see Figure 3b ), the coil portion 240 can have greatly reduced thermal shrinkage at a temperature below the coil contact temperature).

[0092] Control of the coil contact temperature can provide one type of control over the stiffness (eg, effective modulus) of the actuator. In various embodiments, when the coil portions 240 are in contact, the actuator can become more rigid, which can be useful in designs incorporating fiber actuators.

[0093] In some examples, the extension of the actuator can be controlled by winding the fiber around the actuator so that the actuator is an environmentally responsive core protected in the yarn. As the actuating core is extended, the outer fiber (e.g., continuous filaments, staple fibers, etc.) can be pulled into an increasingly linear orientation, and the outer fiber can be straight enough to resist tensile extension. At this moment, in various examples, the actuator can enter the thermal response zone, where the winding fiber greatly hinders additional extension, thereby effectively producing the maximum length for the actuator. In some embodiments, winding or covering the curling actuator can bring many other benefits, including improved feel, appearance, anti-hook yarn, control wicking, moisture treatment, chemical resistance, the total volume of the actuated yarn, etc. Winding can also be used to balance the torque of the fiber actuator. For example, the actuator can be constrained at both ends to convert the twisting action of the coil into a linear dimensional change that changes with temperature. If the actuator is wound with fibers or plying with fibers along the opposite twist direction (e.g., a Z-shaped twisting actuator can be wound with fibers or plying with fibers along the S direction), this constraint requirement can be eliminated.

[0094] While various examples disclosed herein relate to thermal response of the curl actuator, the materials may be moisture sensitive and / or chemically sensitive, in addition or in the alternative, and where temperature or environmental response or adaptation is involved, moisture sensitivity, water sensitivity, and / or chemical sensitivity is meant to be included.

[0095] Various embodiments described herein may include monofilament or multifilament yarn. However, in another example, staple yarn may be used to generate a curled thermal actuator. In some embodiments, the individual fibers in such yarns may be cross-linked by surface-surface interactions, or the yarn in an extended form in which the coil is separated may be impregnated with a cross-linking agent or a polymerizing agent to improve the long-term integrity of the thermally responsive yarn. In some examples, the yarn itself may be used as a medium for dispensing a liquid polymerizing agent by wicking. Similarly, a material may be used as a coating on a staple or multifilament yarn to be used as a filler or glaze. Such materials may include a sizing agent applied as a solution, or may include a polymer applied by a melting process. In some embodiments, the protective material may be removed after the twisting and curling of the fiber or yarn actuator, and the protective material may be used as a sacrificial material to assist in generating the actuator.

[0096] Produce a spring with the desired geometry (e.g., high spring index C 、Low roll angle α 卷 An example method of forming a coil (e.g., a coil portion 240 with controlled spacing 260 between coil portions 240, etc.) may include braiding one or more pre-twisted (but in some examples not curled) fibers 100 with one or more sacrificial fibers. The braiding may be done with or without a core 510. The braid may be heat set, and the sacrificial fibers and core may be removed by physical means, dissolving, melting, washing, chemical methods, etc.

[0097] Produce a spring with the desired geometry (e.g., high spring index C 、Low roll angle α 卷 Another example method of forming a roll (such as a roll having a controlled spacing 260 between roll portions 240, etc.) can include wrapping or winding one or more pre-twisted (but in some examples not curled) fibers 100 around one or more sacrificial fibers or yarns. The one or more sacrificial fibers can define the geometry of the central cavity 220 of the roll formed around the one or more sacrificial fibers. The wrapped or covered fibers or yarns can be heat set, and one or more sacrificial fibers can be removed by physical means, dissolving, melting, washing, chemical methods, etc., thereby releasing the wrapped fiber roll from the core. In this example method of actuator generation, the sacrificial core can be used as a template or structure, and the fibers can be wound thereon. The fibers or yarns used to be wound around the core can be monofilaments, continuous filament yarns, or can be staple yarns, which are optionally prepared with removable sizes and / or lubricants to facilitate the formation of a curled structure.

[0098] In some examples (including thin yarns that may have a high spring index), the effective modulus may be too low to achieve the desired thermal or mechanical properties. To increase the effective modulus, the rolls may be wound on an elastic or non-elastic core during production, which may retain a portion of the yarn in the final product. In some examples, the rolls may also be wound on a multi-component core, where a portion of the core may be removed after winding / heat setting, by chemical or physical means, etc.

[0099] The winding of one or more fibers 100 on the sacrificial core 510 can also be used for cross-yarn covering (wherein a first group of one or more fibers 100 are wound on the core 510 in one direction (S or Z)), followed by additional covering (wherein a second group of one or more fibers 100 are wound on the core 510 and the first winding in the opposite direction (Z or S), which first winding may include the first group of one or more fibers 100). In some embodiments, both the first and second groups of fibers 100 can be highly twisted, thereby producing a nested curl actuator in which an outer homochiral roll with Z twist surrounds an inner homochiral roll with S twist, or an outer homochiral roll with S twist surrounds an inner homochiral roll with Z twist, which can produce a balanced or partially balanced actuated yarn. In some embodiments, only one of the first or second groups of fibers is highly twisted, and the other group of fibers may be present for support, suppression, protection, capacity enhancement, or other suitable purposes.

[0100] For fibers or yarns with smaller diameters (e.g., less than 0.25 mm), commercially available winding or covering machinery may not be able to provide the appropriate twist or curl level per linear length to produce a yarn with minimized curl angle α. 卷 A compact curling actuator. In a non-limiting example, a winding machine capable of curling <5000 rolls per meter can wind a central sacrificial fiber or yarn with a highly twisted 100 micron filament, thereby leaving a space of >100 microns between each roll. Such intervals can be left in the curled material, but alternatively, a second highly twisted filament (or a second and a third, or a second and a third and a fourth, etc.) can be wound on the central core material at the same time, thereby forming two rolls, each of which is nested inside another roll. Although in some examples, the environmental response will not change due to the presence of nested rolls, one or more nested rolls can have some differences in nature. For example, due to the presence of a second roll, the contraction range can be reduced. In another example, the total combined stiffness of the nested rolls can be higher than the combined stiffness of a single roll. In terms of production, in various examples, adding a second filament may not increase the processing time of the curling step, but can improve reliability, because two (or more) filaments can be settled against each other during the production process and effectively constrain each other.

[0101] In some embodiments, it may not be necessary to apply heat to shape the roll in the desired geometry. For example, mechanical shaping by plastic deformation may be used. In some examples, chemical methods may also be used to remove residual mechanical stresses and shape the roll in the desired geometry.

[0102] Fibers with special cross-sections (including hollow core precursor fibers, etc.) can be used to increase the insulation value and reduce the weight of some actuators produced by the fibers. In various embodiments, non-circular cross-sections can increase the surface area of ​​the fiber 100, thereby providing enhancements in wicking, dryness, feel, etc.

[0103] A curling actuator or artificial muscle including one or more curling fibers 100 as discussed herein can have various suitable applications in clothing, bedding, curtains, insulation, etc. For example, in some embodiments, clothing such as coats, sweaters, etc. can include an adaptive fabric, which includes a plurality of curling actuators, which include a plurality of curling fibers 100, wherein a first layer of adaptive fabric is configured to surround and face the wearer's body, and a second layer is configured to face the wearer's external environment. Such a configuration can include a lining and / or an outside, and the adaptive fabric can be placed in the lining and / or the outside. In other embodiments, only a single adaptive layer can be used in clothing or other products.

[0104] In various embodiments, garments including adaptive fabrics can be configured to change configuration based on the wearer's body temperature and / or the temperature of the external environment, which can include lofting or flattening to provide increased or decreased insulation based on temperature. For example, in the case where the ambient temperature is cooler than the desired comfort temperature of the user's immediate environment (e.g., approximately 27° C.), the outer and / or inner layers of the adaptive fabric can be configured to loft to provide improved insulation to protect the user from the cold, with greater loft and insulation at lower temperatures. Alternatively, in the case where the ambient temperature is warmer than a comfortable temperature for the user, the outer and / or inner layers of the adaptive fabric can be configured to flatten, thereby providing reduced insulation to the user.

[0105] Additionally, the adaptive fabric of the garment can be configured to change configuration based on moisture associated with the wearer's body and direct such moisture away from the wearer's body. For example, as a user sweats and generates moisture while wearing a garment including the adaptive fabric, the adaptive fabric can be configured to become more porous and / or flatten to allow such moisture to escape from within the garment toward the exterior of the garment and away from the user.

[0106] Adaptive fabrics or textiles including multiple curling actuators can be produced in various suitable ways and can have various suitable properties. For example, the difference in coefficient of thermal expansion (ΔCTE) between two materials is a term that can indicate the range of motion or deflection of a structure (such as a bimorph or other structure having multiple curling actuators). For some example materials, the ΔCTE term can be 100 to 200 μm / m / K, which may be undesirable for some embodiments. Thus, various embodiments of bimorphs can include highly twisted curling actuators as described herein (e.g., Fig.15a , Fig.15b , Fig.16a , Fig.16b , Fig.17a , Fig.17b and Fig.18 ), which in some embodiments may have an effective CTE value of 1000 μm / m / K or greater, thereby providing a ∆CTE value of the same magnitude. In some examples, such CTE values ​​may be used for bimorphs and bilayer structures having desired deflection or bending characteristics.

[0107] In various embodiments, the curling actuator can be used as a thermally responsive tensile actuator (linear motion) and / or a torsion actuator (rotational motion). In further embodiments, by using supplementary materials, the structures described herein can convert the linear motion of the curling actuator into motion in an orthogonal direction. Such embodiments may be desirable for use in thermally responsive yarns, padding, felts, fabrics, and the like, which may include garments and other articles that thicken when exposed to low temperatures.

[0108] In various embodiments, it may be desirable to pair materials where the difference between the CTE values ​​of the two paired materials (∆CTE) is large. Thus, curling actuators 1210 having large CTE values ​​may be desirable for use in bimorphs and structures including bimorphs. In some embodiments, the curling actuators may have positive CTE characteristics (e.g., expansion with increasing temperature, heterochiral curls with opposite twist and roll directions) or large negative CTE characteristics (e.g., contraction with increasing temperature, homochiral curls with the same twist and roll directions). In various embodiments, and as described herein, pairing together opposing curling actuators comprising the same filament material may produce a larger ∆CTE.

[0109] In various embodiments, the bimorph may include a twist-coil actuator, wherein linear displacement of the actuator due to temperature changes may induce out-of-plane or orthogonal deflections in the bimorph, resulting in an effective change in the height or thickness of the bimorph.

[0110] Fig.15a and Fig.15bOne example 1500A of a bimorph 1500 is illustrated that includes a curled actuator fiber 100 and a filament 1520 coupled at a first end 1530 and a second end 1540. The curled actuator fiber 100 and filament 1520 may be coupled only at the first end 1530 and the second end 1540 and / or may be coupled along a portion of their length.

[0111] In various embodiments, the curled actuator fiber 100 can expand or contract lengthwise in response to temperature changes. For example, the curled actuator fiber 100 can contract when cooled (heterochiral fiber actuator, twist and roll directions are opposite) or expand when cooled (homochiral fiber actuator, twist and roll directions are the same). In various embodiments, the filament 1520 can expand, contract, or exhibit no substantial change lengthwise.

[0112] Fig.15a The bimorph 1500A is illustrated in two configurations: a flat configuration at a first temperature on the left, and a first contracted configuration caused by a change in temperature on the right. Fig.15b The diagram shows the following two configurations: Fig.15a The bimorph 1500A: the left one is in a flat configuration at a first temperature, and the right one is in a flat configuration at a first temperature. Fig.15a The second contraction configuration is caused by a temperature change different from the temperature change shown in FIG. Fig.15a Configuration changes based on negative temperature changes can be illustrated, and Fig.15b Configuration changes based on positive temperature changes can be illustrated.

[0113] In various embodiments, the curled actuator fiber 100 and the filament 1520 can be configured to both bend, such as Fig.15a and Fig.15b , where the lengths of the curled actuator fiber 100 and the filament 1520 are adjacent in both curved and straight configurations. In other embodiments, the curled actuator fiber 100 and the filament 1520 may be configured to bend in different ways, and the curled actuator fiber 100 and the filament 1520 may not be adjacent in the flat and / or curved configurations.

[0114] For example, Fig.16a An example embodiment 1500B of a bimorph 1500 is illustrated having a coiled actuator fiber 100 and filaments 1620, wherein the coiled actuator fiber 100 maintains a linear configuration when the bimorph 1500 is in a flat configuration (left) and a bent configuration (right). In this example, the coiled actuator fiber 100 is shown to contract due to a temperature change, which causes the filaments 1620 to bend away from the coiled actuator fiber 100.

[0115] Similarly, Fig.16bAnother example 1500C of a bimorph 1500 is illustrated, which includes a first filament 1620A and a second filament 1620B, with a coiled actuator fiber 100 between the first filament 1620A and the second filament 1620B. In this example, the bimorph 1500C is shown to contract due to temperature changes, which causes the filaments 1620A, 1620B to bend away from the coiled actuator fiber 100, which remains in a linear configuration.

[0116] Fig.17a and Fig.17b Two examples 1500D, 1500E of bimorphs 1500 are illustrated that include a first crimped actuator fiber 100A1 and a second crimped actuator fiber 110B1 coupled at a first end 1530 and a second end 1540. In some embodiments, the crimped actuator fibers 100A1, 110B1 may be coupled along a portion of their length. Fig.17a An example embodiment 1500D is illustrated in which the curled actuator fibers 100A1, 110B1 have opposite thermal responses and remain contiguous in both flat (left) and bent (right) configurations. Fig.17b An example embodiment 1500E is illustrated in which crimped actuator fibers 100A1 , 110B1 are abutted in a flat configuration (left) and can be separated in a bent configuration (right).

[0117] Fig.18 An example embodiment of a bimorph 1500F is illustrated having a curled actuator fiber 100 and a filament 1520, wherein the filament 1520 maintains a linear configuration when the bimorph 1500 is in a flat configuration (left) and a bent configuration (right). In this example 1500F, the curled actuator fiber 100 is shown to contract due to a temperature change, which causes the curled actuator fiber 100 to bend away from the filament 1520.

[0118] In various embodiments, one or more twisted coil actuator fibers 100 can be coupled to one or more rigid reverse filaments 1520, which can serve as a fixed structure against which the actuator fiber 100 can be orthogonally displaced to form a structure with minimal linear expansion that still changes its effective thickness. Fig.18 An example of such a structure is shown in the figure.

[0119] In addition to the desired effective CTE value, the coiled actuator fiber 100 may also provide some processing or manufacturing advantages, such as mechanical connection routes not available with sheet structures and the advantages of producing both positive and negative CTE coils from the same length of material as discussed herein. When the spring constant of the coiled actuator fiber 100 is large, the effective CTE value of the coiled actuator fiber 100 can be maximized, leaving an open cavity 220 at the center of the coil. The coiled actuator fiber 100 may also be desirable due to the porosity, density, and air permeability that may exist in such a structure, among other things.

[0120] In various embodiments, one or more curled actuator fibers 100 and / or bimorphs 1500 may be woven or stitched through a fabric or film to produce a bimorph sheet structure having a large effective ∆CTE value and a corresponding large deflection. In other embodiments, one or more curled actuator fibers 100 may be stitched or bonded to a sheet to form a bimorph sheet. In some embodiments, one or more curled actuators may be stitched or bonded to the surface of a sheet or fabric, the curled actuators having alternating curl segments having alternating expansion and contraction segments of opposite chirality. A sheet structure may be formed in which the sheet or ribbon exhibits a sinusoidal curve as the temperature changes (due to the positive and negative thermal response regions within the alternating chirality curled actuator fibers 100). Embodiments of the alternating chirality curled actuator may have applications in a variety of fields. For example, various embodiments can be configured to create thermally adaptive clothing, where alternating chiral coils can be used in a conventional lockstitch to create alternating positive and negative CTE regions on the surface of the fabric, thereby inducing undulations in the fabric as temperature changes. In some embodiments, the second yarn or fiber in the lockstitch need not be a large CTE or twisted coil actuator material.

[0121] In some embodiments, multiple curled actuator fibers 100 can be laid side by side and woven or stitched together to produce a sheet or layer with a desired CTE in a single direction. In still other embodiments, such sheets with different CTEs (e.g., a sheet with a large positive CTE and a sheet with a large negative CTE) can be paired to produce a flat bimorph sheet with a desired thermal expansion difference and a desired radius of curvature.

[0122] In further embodiments, the curled actuator fiber 100 can be sewn to a film, membrane, or fabric, which can impart thermally responsive properties to such film, membrane, or fabric. Thus, various embodiments can eliminate the need for more in-depth integration of the selected material with the insulation material or fabric. In such embodiments, additionally, the thermally responsive material can be part of a woven fabric, it can be the primary body of insulation, it can be a substrate, or it can be bonded to another material by an adhesive or thermal bonding.

[0123] Additionally, the curled actuator fiber 100 can be used to create a branching structure similar to the branching structure in goose down. For example, in some embodiments, in the context of variable thermal insulation, by dragging the twisted fiber 100 through a layer of fine fibers during the curling process, the fine fibers can be captured or trapped in the coil, thereby forming a branching structure with advantageous thermal insulation, tactile and structural properties.

[0124] The curled actuator fiber 100 can be used as a linear or torsional actuator. In various embodiments, as discussed herein, pairing two different materials can produce out-of-plane or orthogonal motion. In some embodiments, a woven or knitted structure that unfavorably pairs twisted coils with different CTE characteristics can include a thermally responsive bimorph 1500. In some embodiments, a variety of materials can be woven together in various suitable ways to produce an overall physical structure of a woven fabric that changes in response to temperature. Such woven structures can include the curled actuator fiber 100, or other suitable materials or structures that change configuration or length in response to temperature.

[0125] In various embodiments, a woven or knitted structure can act as a constraint by aligning the fibers so that the overall motion is cohesive and not characterized by random individual creeping of different groups of fibers, which can be desirable for thermally adaptive materials and to maximize their deflection or their effective thickness change.

[0126] In further embodiments, the temperature sensitive structure may include non-adaptive constraints, such as fibers, yarns, or fabrics that the active material is not favored, wherein the non-adaptive material remains linear, straight, or flat and the active material lofts due to expansion, or wherein the active material remains linear, straight, or flat and the non-adaptive material lofts due to contraction of the active material. Appropriate constraints may produce the desired temperature response in such structures, either by weaving, knitting, or using adhesives. In some embodiments, it may be advantageous to employ constraints that limit the range of motion of the material.

[0127] In other embodiments, the curled actuator fiber 100 or an artificial muscle including one or more curled fibers 100 can be used in various suitable ways, including one or more of the following: (i) textiles or woven fabrics; (ii) mechanical mechanisms for opening and closing blinds or roller blinds to adjust light transmission or airflow; (iii) mechanical actuators for medical devices or toys; (iv) macro- or micro-sized pumps, valve actuators, or fluid mixers; (v) mechanical relays for opening and closing electronic circuits or opening and closing locks; (vi) torsional actuators for rotating electrodes used in high-sensitivity electrochemical analyte analysis; (vii) mechanical actuators for optical devices; (viii) mechanical actuators for optical devices that open and close optical shutters, translate or rotate lenses or light diffusers, provide deformations that change the focal length of compliant lenses, or rotate or translate pixels on a display to provide changing images on the display; (ix) mechanical actuators that provide tactile information; (x) mechanical actuators for surgeon gloves or Braille displays. (xi) Mechanical actuators for providing tactile information to tactile devices in displays; (xi) Mechanical actuator systems for smart surfaces that enable changes in surface structure; (xii) Mechanical actuator systems for exoskeletons, prostheses or robots; (xiii) Mechanical actuator systems for providing realistic facial expressions to humanoid robots; (xiv) Smart packaging for temperature-sensitive materials that respond to ambient temperature to open and close vents or change porosity; (xv) Mechanical systems that respond to ambient temperature or temperature generated by photothermal heating to open or close valves; (xvi) Mechanical actuators using photothermal heating or electrical heating to control the orientation of solar cells relative to the direction of the sun; (xvii) Photothermally actuated microdevices; (xviii) Thermal or photothermally actuated energy harvesters that use temperature fluctuations to generate mechanical energy that is harvested as electrical energy; (xix) Tight clothing, where thermal actuation is used to facilitate entry into clothing; (xx) Devices for providing adjustable compliance, where the adjustable compliance is provided by electrothermal actuation; (xxi) Translational or rotational positioners, etc.

[0128] The described embodiments are susceptible to various modifications and alternative forms, but specific examples thereof have been shown by way of example and are described in detail herein. However, it should be understood that the described embodiments will not be limited to the specific forms or methods disclosed, but on the contrary, the present disclosure will cover all modifications, equivalents and alternatives.

[0129] First and second examples Fig.13 and Fig.14 Two environmentally responsive coiled fiber actuators produced according to the methods described herein are shown. Fig.13 and Fig.14Microscope images showing volumes with geometry produced by two different methods. The scale bar is 0.5 mm in length.

[0130] exist Fig.13 In the invention, a highly twisted fiber coil was made from 0.1 mm polyamide filaments by twisting under tension to the point of inducing coiling, twisting the coil in the opposite direction under reduced load (untwisting), and heat setting. The coil index was measured and found to be about 2.9, and the linear thermal expansion coefficient in the axial direction of the fiber actuator was measured and found to be -4.2 mm / m / K.

[0131] exist Fig.14 In the present work, a highly twisted fiber coil was made from 0.1 mm polyamide filaments by twisting under tension before the moment of inducing curling, then winding around a sacrificial fiber core, and then heat setting and removing the core. The coil index was measured and found to be about 2.8, and the linear thermal expansion coefficient in the axial direction along the fiber actuator was measured and found to be -4.6 mm / m / K. Both coiled fiber actuators were made from the same polyamide filament, and both coils were homochiral, with a negative thermal expansion coefficient, expanding when cooled rather than heated. The twisted coiled material ( Fig.13 ) shows small spaces between each other, while the coiled material ( Fig.14 ) are touching or nearly touching.

[0132] Additional Examples Using the techniques described above, thermal actuators with CTE values ​​above 5 mm / m / K have been produced (for coils with negative thermal expansion, the average value of the negative thermal expansion is less than -5 mm / m / K or -0.005 / K), and actuators with values ​​above 2 mm / m / K have also been produced. All of these example embodiments are close to body temperature actuation and enable the production of responsive textiles suitable for apparel applications.

[0133] Fig.19 Presented are graphs with various volume index values ​​( C ) for more than 200 twisted and coiled homochiral fiber actuators. The dashed line represents the linear fit of the data ( R 2 = 0.7). No data are for mandrel-wound or core-wound actuators; all data represent coils produced by twisting to the point of inducing coiling. To achieve coil index values ​​above approximately 1.75, the as-spun coils are partially untwisted, thereby increasing the coil index value and the magnitude of the linear expansion coefficient. In general, coils with larger coil spring indexes ( C) have coil contact temperatures high enough to allow expansion and contraction close to body temperature. These coils have larger spring indices, are made of different materials, and are placed under different conditions. They also exhibit variability in the spacing between coils and the coil deflection angles, explaining the C The data represent rolls produced from fibers in the polyamide, polyester, and polyolefin families, with the diameter sizes of the various fibers or yarns ranging from 0.05 mm to greater than 0.3 mm. The data also represent rolls that were heat set under a range of conditions.

[0134] Table 1 summarizes the coefficient of thermal expansion data measured from a series of twisted and coiled polyester fiber actuators heat set at different temperatures. Six (6) fiber actuators were produced for annealing at each of 140°C, 170°C, and 200°C, for a total of 18 fiber actuators. These actuators were all produced under similar conditions and were nominally identical prior to the annealing step. At each temperature, half of the fiber actuators annealed were S-twisted homochiral actuators and half were Z-twisted homochiral actuators. All three heat setting conditions were suitable for producing large-stroke thermally responsive materials, but the lower temperatures of 140°C and 170°C produced fiber actuators with significantly larger thermal response amplitudes. Each heat setting procedure was implemented for two (2) hours.

[0135] Table 1: Summary data of twisted and coiled polyester fiber actuators heat set at different temperatures Even for materials with high melting points, lower temperature heat setting conditions can be used. For example, autoclave conditions (121°C saturated and pressurized steam for 15 to 20 minutes) can be sufficient to moderate some twist instabilities in highly twisted polyamides, which can reduce the tension required to reliably handle highly twisted and / or curled materials. Generally, it is desirable to heat set at a temperature above the glass transition temperature of the material, which is typically less than 100°C for common polymers used in textiles (such as polyesters and polyamides). For polyolefin materials, the glass transition temperature can be much lower, often below 0°C, and heat setting temperatures of less than 100°C are often sufficient.

[0136] Using the techniques described herein, it has been shown that twisting the fiber to the point of inducing coiling can produce homochiral coiled fiber actuators with effective linear thermal expansion coefficient values ​​greater than -9 mm / m / K. Additional optimizations are possible, and such values ​​are not an upper limit on performance. Furthermore, methods of winding the twisted fiber around a core can produce similar results and can enable excellent control over the coil structure produced in some examples, thereby providing a path to better performance.

[0137] Embodiments of the present disclosure may be described in terms of the following: 1. A method of constructing a thermally adaptive garment configured to be worn on a user's body and to at least partially surround a portion of the user's body, the thermally adaptive garment comprising: Producing a plurality of coiled actuator fibers, wherein each of the plurality of coiled actuator fibers is produced by: The fiber is twisted to produce a highly twisted fiber having a fiber deflection angle α 纤维 between 25° and 50°; winding the highly twisted fiber around a sacrificial core to create a coil in the highly twisted fiber; setting the highly twisted fiber roll by applying heat or a chemical setting agent to the highly twisted fiber roll disposed on the sacrificial core; and The sacrificial core is removed by dissolving it in a solvent to produce a coiled actuator fiber having the following properties: Coil spring index greater than or equal to 2.0 ( C ), The coil part contact temperature is greater than or equal to 20°C, Thermal response with |CTE| ≥ 2 mm / m / K, and Fiber deviation angle α between 25° and 50° 纤维 ; producing a thermally adaptive fabric comprising the produced plurality of crimped actuator fibers; Producing a garment body defined by the thermally adaptive fabric, the garment body comprising: an inner portion having an inner surface configured to face toward the body of a wearing user; and an outer portion having an outer face configured to face an environment external to the wearing user, wherein the thermally adaptive fabric is configured to assume a base configuration in response to a first ambient temperature range, and wherein the thermally adaptive fabric is configured to assume a lofted configuration in response to a second ambient temperature range separate from the first ambient temperature range.

[0138] 2. A method according to clause 1, wherein the fiber comprises one of: a yarn comprising one or more fibers, or a fiber comprising a single elongated element.

[0139] 3. A method according to clause 1 or 2, wherein the sacrificial core is removed by dissolving in water.

[0140] 4. A method according to any one of clauses 1 to 3, wherein the sacrificial core comprises a water-soluble polymer monofilament, filament yarn or staple fiber yarn.

[0141] 5. A method according to any one of clauses 1 to 4, wherein the sacrificial core is removed after the crimped actuator fibers have been incorporated into a fabric.

[0142] 6. A method of producing a plurality of curled actuator fibers, wherein each of the plurality of curled actuator fibers is produced by: The fiber is twisted to produce a twisted fiber, wherein the fiber deviation angle α of the twisted fiber is 纤维 between 25° and 50°; winding the twisted fiber around a sacrificial core to create a coil in the twisted fiber; setting the highly twisted fiber roll by applying heat or a chemical setting agent to the twisted fiber roll disposed on the sacrificial core; and The sacrificial core is removed by dissolving the sacrificial core in a solvent to produce a coiled actuator fiber having two or more of the following properties: Coil spring index greater than or equal to 2.0 ( C ), The coil part contact temperature is greater than or equal to 20°C, Thermal response with |CTE| ≥ 2 mm / m / K, and Fiber deflection angle α between 25º and 50º 纤维 .

[0143] 7. A method according to clause 6, wherein the fiber comprises one of: a yarn comprising one or more fibers or other elements, or a fiber comprising a single elongated element.

[0144] 8. A method of producing a curled actuator fiber, the method comprising: twisting the fibers to produce twisted fibers; winding the twisted fiber around a core to create a coil in the twisted fiber; and At least a portion of the core is removed to produce a crimped actuator fiber.

[0145] 9. A method according to clause 8, wherein the fiber comprises one of: a yarn comprising one or more fibers, or a fiber comprising a single elongated element.

[0146] 10. The method according to clause 8 or 9, further comprising: shaping the curled actuator fiber by heating or chemical treatment.

[0147] 11. The method of clause 10, wherein shaping the twisted fiber roll is performed prior to partially or completely removing the core.

[0148] 12. A method according to clause 10, wherein shaping of the twisted fiber coil is performed on a bobbin of the curl actuator fiber.

[0149] 13. A method according to any one of clauses 8 to 12, wherein the coiled actuator fiber comprises a coil spring index ( C ).

[0150] 14. The method of any one of clauses 8 to 13, wherein the coiled actuator fiber comprises a coil portion contact temperature greater than or equal to 10°C.

[0151] 15. A method according to any one of clauses 8 to 14, wherein the curled actuator fiber comprises a thermal response of |CTE| ≥ 2 mm / m / K.

[0152] 16. A method according to any one of clauses 8 to 15, wherein the method further comprises: winding at least two twisted fibers around a core to create a coil in the twisted fibers.

[0153] 17. A method according to any one of clauses 8 to 16, wherein the core is removed by: a. dissolve; b. Chemical reaction; c. or a combination thereof.

[0154] 18. The method of clause 17, wherein the core further comprises a non-removable portion that is insoluble or chemically non-reactive under the same conditions as the removable portion, thereby leaving a portion of the core.

[0155] 19. A method according to any one of clauses 8 to 18, wherein twisting the fiber to produce the twisted fiber comprises: twisting the fiber to have a fiber bias angle α greater than 25° 纤维 .

[0156] 20. A method according to any one of clauses 8 to 19, wherein twisting the fiber to produce the twisted fiber comprises twisting the fiber to have a fiber bias angle α between 30° and 40° 纤维 .

[0157] 21. A method for making a coiled fiber actuator having physical spaces between coils thereof when: a. said curly fibers are at body temperature, and b. No load, Wherein, the crimped fiber actuator is shaped by at least one of the following: a. Heat, or b. Chemical treatment While being under physical constraints that prevent substantial expansion or contraction of the crimped fiber actuator during the shaping process.

[0158] 22. The method of clause 21, wherein the coiled actuator fiber comprises a coil spring index ( C ).

[0159] 23. A method according to clause 21 or 22, wherein the curled fiber actuator comprises a thermal response of |CTE| ≥ 2mm / m / K.

[0160] 24. A method according to any one of clauses 21 to 23, wherein the physical constraint applied during shaping is applied to the bobbin of the coiled fiber actuator.

[0161] 25. A method according to any of clauses 21 to 24, wherein the physical constraints applied during shaping: a. preventing substantial expansion or contraction of the curled fiber actuator during the shaping process, and b. Holding the coiled fiber actuator in a position where there is physical space between its coils.

[0162] 26. The method of any one of clauses 21 to 25, wherein the crimped fiber actuator is heat set at a temperature greater than or equal to 121°C.

[0163] 27. A method according to any one of clauses 21 to 26, wherein the crimped fiber actuator has a physical space between its coils when: a. The curled fibers are at room temperature, and b. No load.

[0164] 28. A method for making a coiled fiber actuator having physical spaces between coils thereof when: a. said curly fibers are at body temperature, and b. No load, wherein, after initial formation of the coil, the coiled fiber actuator is twisted under the following conditions: a. in a direction opposite to the twist direction used to form the roll, b. being under a tension less than the tension applied to the fibers during initial roll formation, c. and only to the extent that a substantial portion of said initially formed coil remains intact, and wherein the partially untwisted coiled fiber actuator is shaped by at least one of: a. Heat, or b. Chemical treatment.

[0165] 29. The method of clause 28, wherein the coiled actuator fiber comprises a coil spring index ( C ).

[0166] 30. A method according to clause 28 or 29, wherein the curled fiber actuator comprises a thermal response of |CTE| ≥ 2mm / m / K.

[0167] 31. The method of any one of clauses 28 to 30, wherein the crimped fiber actuator is heat set at a temperature greater than or equal to 121°C.

[0168] 32. A method according to any one of clauses 28 to 31, wherein the crimped fiber actuator has a physical space between its coils when: c. the curled fibers are at room temperature, and d. No load.

[0169] 33. A method for making a coiled fiber actuator having physical spaces between coils thereof when: e. said curled fibers are at body temperature, and f. No load, Wherein, the curled fiber actuator is produced by the following method: a. twisting the fibers to produce twisted fibers, b. winding the twisted fiber around a sacrificial core to create a coil in the twisted fiber, and c. removing at least a portion of the sacrificial core to produce a curled actuator fiber, and wherein the crimped fiber actuator is shaped by at least one of: a. Heat, or b. Chemical treatment.

[0170] 34. A method according to clause 33, wherein the core is removed by dissolution.

[0171] 35. A method according to clause 33 or 34, wherein the core is completely removed.

[0172] 36. A method according to any of clauses 33 to 35, wherein the twisted fibres are shaped to produce a roll before being wound onto a core.

[0173] 37. A method according to any one of clauses 33 to 36, wherein the twisted fiber has a fiber bias angle equal to or greater than 20°.

[0174] 38. A method according to any one of clauses 33 to 37, wherein the curled fiber actuator comprises a thermal response of |CTE| ≥ 2 mm / m / K.

[0175] 39. A method according to any one of clauses 33 to 38, wherein the curled fiber actuator is heat set prior to removing the core.

[0176] 40. A method according to any one of clauses 33 to 39, wherein the crimped fiber actuator has a physical space between its coils when: g. The curled fibers are at room temperature, and h. No load.

[0177] 41. A coiled fiber or yarn actuator made from a highly twisted fiber or yarn wrapped or coiled around a sacrificial core, wherein the sacrificial core has been partially or completely removed.

[0178] 42. A curled fiber or yarn actuator according to claim 41, wherein the fiber bias angle is between 25° and 45°.

[0179] 43. A curled fiber or yarn actuator according to claim 41 or 42, wherein the sacrificial core has been removed by dissolution.

[0180] 44. A coiled fiber or yarn actuator as described in any of clauses 41 to 43, wherein the sacrificial core has been removed by dissolution in water.

[0181] 45. A coiled fiber or yarn actuator according to any one of clauses 41 to 44, wherein the sacrificial core is a water soluble polymer monofilament, filament yarn or staple yarn.

[0182] 46. ​​A coiled fiber or yarn actuator according to any one of clauses 41 to 45, wherein the coiled fiber or yarn actuator is shaped by thermal or chemical means prior to removal of the sacrificial core.

[0183] 47. A method of producing a coiled fiber or yarn actuator, the method comprising: a. to twist the fibers or yarns, b. winding or curling the twisted fibers or yarns around a sacrificial core material, and c. Partially or completely removing the sacrificial core material.

[0184] 48. A method of changing coil geometry in a coiled fiber or yarn actuator, the method comprising: a. applying a tension equal to or less than the tension applied during formation of the roll, and b. untwisting the coil to increase the coil index of the coiled fiber or yarn actuator.

[0185] 49. A method according to claim 48, wherein the tension applied during untwisting is less than 50% of the tension applied during forming the roll.

[0186] 50. A method according to clause 48 or 49, wherein the diameter of the roll is monitored during untwisting and the diameter data is used to control at least one of the following process parameters: a. Tension, b. Retrieval rate, or c. Twisting rate.

[0187] 51. A coiled fiber or yarn actuator made from a highly twisted fiber or yarn that has been coiled by inserting twist under a first tension and untwisting under a second tension that is sufficient to change the coil index of the coiled fiber or yarn actuator.

[0188] 52. A coiled fiber or yarn actuator according to claim 51, wherein a second coiled fiber or yarn actuator produced under the same twisting, coiling and shaping conditions but without an untwisting step has a lower coil contact temperature than a coil produced by the same process including the untwisting step.

[0189] 53. A coiled fiber or yarn actuator according to clause 51 or 52, having at least one of the following: a. A volume index greater than or equal to 2.0, or b. Coil contact temperature above room temperature.

[0190] 54. A method of producing a coiled fiber or yarn actuator, the method comprising: a. twisting the fiber or yarn under a first tension, b. curling the twisted fiber or yarn by one of the following: ⅰ. The moment when the twist is inserted and curled, or ii. winding or curling the twisted fiber or yarn around a sacrificial core or mandrel, and c. untwisting the roll under a second tension.

[0191] 55. A method according to claim 54, wherein the second tension is less than the first tension.

[0192] 56. A method according to clause 54 or 55, wherein the second tension is 10% or less of the first tension.

[0193] 57. A coiled fiber or yarn actuator having physical spaces between its coils under the following conditions: a. the curling actuator is above room temperature, and b. No load, and wherein the coiled fiber or yarn actuator is shaped by at least one of: a. Heat, or b. Chemical treatment While being under physical constraints which prevent substantial expansion or contraction during the shaping process.

[0194] 58. A coiled fiber or yarn as described in claim 57, wherein, prior to setting, the coiled fiber or yarn actuator has a coil in contact with an adjacent coil at room temperature.

[0195] 59. A curled fiber or yarn according to claim 57 or 58, wherein, prior to setting, the curled fiber or yarn actuator is under minimum tension.

[0196] 60. A sensor comprising a camera and image analysis, the image analysis determining at least one from the following list: a. Relative or absolute fiber or yarn diameter, b. Fiber or yarn speed, and c. the location of the fiber or yarn entanglement, and providing production control information to at least one process variable from the following list: a. Tension, b. Retrieval rate, and c. Twisting rate, The production control information is used to produce or process fibers or yarns.

[0197] 61. A fiber actuator produced in a process using a sensor according to clause 60.

[0198] 62. A fiber actuator having a coil index value equal to or greater than 2.0, wherein the coil is produced by inserting twist to the point of inducing cylindrical entanglement.

[0199] 63. A fiber actuator according to clause 62, having a coil contact temperature greater than 20°C.

Claims

1. A method for producing a curled actuator fiber, the method comprising: twisting the fibers to produce twisted fibers; winding the twisted fiber around a core to create a coil in the twisted fiber; as well as At least a portion of the core is removed to produce a crimped actuator fiber.

2. The method according to claim 1, wherein: The fiber comprises one of: a yarn comprising one or more fibers, or a fiber comprising a single elongated element.

3. The method according to claim 1, further comprising: The curled actuator fibers are shaped by heating or chemical treatment.

4. The method according to claim 3, wherein: Shaping the twisted fiber roll is performed prior to partial or complete removal of the core.

5. The method according to claim 3, wherein: Forming of the twisted fiber coil is performed on a spool of the crimp actuator fiber.

6. The method according to claim 1, wherein: The coiled actuator fiber comprises a coil spring index greater than or equal to 2.0 ( C ).

7. The method according to claim 1, wherein: The crimped actuator fiber includes a crimp portion contact temperature greater than or equal to 10°C.

8. The method according to claim 1, wherein: The curled actuator fiber includes a thermal response of |CTE| ≥ 2 mm / m / K.

9. The method according to claim 1, wherein: The method also includes winding at least two twisted fibers around a core to create a coil in the twisted fibers.

10. The method according to claim 1, wherein: Remove the core by: a. dissolve; b. Chemical reaction; c. or a combination thereof.

11. The method according to claim 10, wherein: The core also includes a non-removable portion that is insoluble or chemically non-reactive under the same conditions as the removable portion, thereby leaving a portion of the core.

12. The method according to claim 1, wherein: Twisting the fiber to produce the twisted fiber includes twisting the fiber to have a fiber bias angle α greater than 25°. 纤维 .

13. The method according to claim 1, wherein: Twisting the fiber to produce the twisted fiber includes twisting the fiber to have a fiber bias angle α between 30° and 40° 纤维 .

14. A method for making a coiled fiber actuator having physical spaces between coils thereof when: a. said curly fibers are at body temperature, and b. No load, in, The crimped fiber actuator is shaped by at least one of: c. Heat, or d. Chemical treatment While being under physical constraints that prevent substantial expansion or contraction of the crimped fiber actuator during the shaping process.

15. The method according to claim 14, wherein: The coiled actuator fiber comprises a coil spring index greater than or equal to 2.0 ( C ).

16. The method according to claim 14, wherein: The coiled fiber actuator includes a thermal response with |CTE| ≥ 2 mm / m / K.

17. The method according to claim 14, wherein: The physical constraints applied during shaping are applied to the bobbin of the coiled fiber actuator.

18. The method according to claim 14, wherein: The physical constraints applied during shaping: a. preventing substantial expansion or contraction of the curled fiber actuator during the shaping process, and b. Holding the coiled fiber actuator in a position where there is physical space between its coils.

19. The method according to claim 14, wherein: The crimped fiber actuator is heat set at a temperature greater than or equal to 121°C.

20. The method according to claim 14, wherein: The coiled fiber actuator has physical spaces between its coils when: a. The curled fibers are at room temperature, and b. No load.

21. A method for making a coiled fiber actuator having physical spaces between coils thereof when: a. said curly fibers are at body temperature, and b. No load, in, After initial formation of the coil, the coiled fiber actuator is twisted under the following conditions: a. in a direction opposite to the twist direction used to form the roll, b. being under a tension less than the tension applied to the fibers during initial roll formation, c. and only to the extent that a substantial portion of said initially formed coil remains intact, and wherein the partially untwisted coiled fiber actuator is shaped by at least one of: a. Heat, or b. Chemical treatment.

22. The method according to claim 21, wherein: The coiled actuator fiber comprises a coil spring index greater than or equal to 2.0 ( C ).

23. The method according to claim 21, wherein: The coiled fiber actuator includes a thermal response with |CTE| ≥ 2 mm / m / K.

24. The method according to claim 21, wherein: The crimped fiber actuator is heat set at a temperature greater than or equal to 121°C.

25. The method according to claim 21, wherein: The coiled fiber actuator has physical spaces between its coils when: c. the curled fibers are at room temperature, and d. No load.

26. A method for making a coiled fiber actuator having physical spaces between coils thereof when: e. said curled fibers are at body temperature, and f. No load, The coiled fiber actuator is produced by: a. twisting the fibers to produce twisted fibers, b. winding the twisted fiber around a sacrificial core to create a coil in the twisted fiber, and c. removing at least a portion of the sacrificial core to produce a curled actuator fiber, and wherein the crimped fiber actuator is shaped by at least one of: a. Heat, or b. Chemical treatment.

27. The method according to claim 26, wherein: The core is removed by dissolution.

28. The method according to claim 26, wherein: The core is completely removed.

29. The method according to claim 26, wherein: The twisted fibers are shaped before being wound onto a core to create a roll.

30. The method of claim 26, wherein: The twisted fibers have a fiber bias angle equal to or greater than 20°.

31. The method of claim 26, wherein: The coiled fiber actuator includes a thermal response with |CTE| ≥ 2 mm / m / K.

32. The method of claim 26, wherein: The crimped fiber actuator is heat set prior to removal of the core.

33. The method of claim 26, wherein: The coiled fiber actuator has physical spaces between its coils when: g. The curly fibers are at room temperature, and h. No load.

34. A coiled fiber or yarn actuator made from a highly twisted fiber or yarn wrapped or coiled around a sacrificial core, wherein the sacrificial core has been partially or completely removed.

35. The crimped fiber or yarn actuator of claim 34, wherein the fiber bias angle is between 25° and 45°.

36. The coiled fiber or yarn actuator of claim 34, wherein the sacrificial core has been removed by dissolution.

37. The coiled fiber or yarn actuator of claim 34, wherein the sacrificial core has been removed by dissolving in water.

38. The coiled fiber or yarn actuator of claim 34, wherein the sacrificial core is a water soluble polymer monofilament, filament yarn, or staple yarn.

39. The coiled fiber or yarn actuator of claim 34, wherein the coiled fiber or yarn actuator is set by thermal or chemical means prior to removing the sacrificial core.

40. A method of producing a crimped fiber or yarn actuator, the method comprising: a. to twist the fibers or yarns, b. winding or curling the twisted fibers or yarns around a sacrificial core material, and c. Partially or completely removing the sacrificial core material.

41. A method of changing coil geometry in a coiled fiber or yarn actuator, the method comprising: a. applying a tension equal to or less than the tension applied during formation of the roll, and b. untwisting the coil to increase the coil index of the coiled fiber or yarn actuator.

42. The method of claim 41, wherein the tension applied during untwisting is less than 50% of the tension applied during forming the roll.

43. The method of claim 41, wherein the diameter of the roll is monitored during untwisting and the diameter data is used to control at least one of the following process parameters: a. Tension, b. Retrieval rate, or c. Twisting rate.

44. A coiled fiber or yarn actuator made from a highly twisted fiber or yarn that has been coiled by twist insertion under a first tension and untwisting under a second tension sufficient to change the coil index of the coiled fiber or yarn actuator.

45. A coiled fiber or yarn actuator according to claim 44, wherein a second coiled fiber or yarn actuator produced under the same twisting, coiling and shaping conditions but without an untwisting step has a lower coil contact temperature than a coil produced by the same process including the untwisting step.

46. ​​The crimped fiber or yarn actuator of claim 44, having at least one of the following: a. a volume index greater than or equal to 2.0, or b. Coil contact temperature above room temperature.

47. A method of producing a crimped fiber or yarn actuator, the method comprising: a. twisting the fiber or yarn under a first tension, b. curling the twisted fiber or yarn by one of the following: ⅰ. The moment when the twist is inserted and curled, or ii. winding or curling the twisted fiber or yarn around a sacrificial core or mandrel, and c. untwisting the roll under a second tension.

48. The method of claim 47, wherein: The second tension is less than the first tension.

49. The method of claim 47, wherein: The second tension is 10% or less of the first tension.

50. A coiled fiber or yarn actuator having physical spaces between its coils under the following conditions: a. the curling actuator is above room temperature, and b. No load, and wherein the coiled fiber or yarn actuator is shaped by at least one of: a. Heat, or b. Chemical treatment While being under physical constraints which prevent substantial expansion or contraction during the shaping process.

51. The crimped fiber or yarn of claim 50, wherein: Prior to setting, the coiled fiber or yarn actuator has coils in contact with adjacent coils at room temperature.

52. The crimped fiber or yarn of claim 50, wherein: Prior to setting, the coiled fiber or yarn actuator is under minimum tension.

53. A sensor comprising a camera and image analysis, the image analysis determining at least one from the following list: a. Relative or absolute fiber or yarn diameter, b. Fiber or yarn speed, and c. the location of the fiber or yarn entanglement, and providing production control information to at least one process variable from the following list: a. Tension, b. Retrieval rate, and c. Twisting rate, The production control information is used to produce or process fibers or yarns.

54. A fiber actuator produced in a process using the sensor according to claim 53.

55. A fiber actuator having a coil index value equal to or greater than 2.0, wherein the coil is produced by inserting twist to the point of inducing cylindrical entanglements.

56. The fiber actuator of claim 55 having a coil contact temperature greater than 20°C.

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