Abstract: Methods for fabricating coiled polymer fibers and yarns (high-spring-index coiled fibers and yarns). Methods include inserting twist separately into individual fibers or yarns, plying the fibers or yarns by inserting plying twist, setting the ply structure without permanently binding together the fibers or yarns of different plies so that the ply structure is substantially stable against untwist when torsionally untethered, and then unwrapping the plied fibers or yarns so that a high-spring-index fiber or yarn can be obtained. In some embodiments, the unwrapped fibers or yarns are further set so that these are further stabilized. The methods can eliminate the need for a mandrel, and can be quickly applied for applications where high-spring-index thermally-driven artificial muscles are presently employed, such as for presently commercialized comfort-adjusting jackets.

Abstract: Improved electrochemical yarn energy harvesters that convert mechanical energy to electrical energy. These harvesters include an ionically conducting electrolyte, and an electronically conducting material, and a material that can undergo charge injection, which can also be the electronically conducting material. At least one device electrode is either twisted, twisted and coiled, or twisted and plied.

Abstract: Previous electrochemically-powered yarn muscles cannot be usefully operated between extreme negative and extreme positive potentials, since strokes during electron injection and during hole injection partially cancel because they are in the same direction. Unipolar-stroke carbon nanotube yarn muscles are described in which muscle strokes are additive between extreme negative and extreme positive potentials, and stroke increases with potential scan rate. These electrochemical artificial muscles include an electrically conducting twisted or coiled yarn and a material that dramatically shifts the potential of zero charge of the electrochemically actuated yarn.

Abstract: Actuators (artificial muscles) comprising twisted polymer fibers generate actuation when powered thermally. In some embodiments, the thermally-powered polymer fiber actuator can be incorporated into an article, such as a textile or garment.

Abstract: Sheath-run artificial muscles (or SRAMs) are described in which the dimensional changes and/or modulus changes of a sheath on the surface of a twisted or coiled host yarn or fiber drives torsional and tensile actuation. The sheath-core artificial muscle includes a sheath on a coiled core yarn or fiber that has inserted twist, in which the sheath does not include a yam, the coiled core yarn or fiber includes a core yarn or fiber, the sheath can change volume, modulus, or a combination thereof when actuated by an influence source to drive actuation, and the influence source is selected from a group consisting of absorption processes, desorption processes, changes in temperature, changes in external pressure, changes in a magnetic field, changes in an electric field, exposures to actinic radiation, electrochemical charge and discharge, chemical reactions, and combinations thereof.

Abstract: Actuators (artificial muscles) comprising twisted polymer fibers generate tensile actuation when powered thermally. In some embodiments, the thermally-powered polymer fiber tensile actuator can be incorporated into an article, such as a textile or garment.

Abstract: Methods for fabricating coiled polymer fibers and yarns (high-spring-index coiled fibers and yarns). Methods include inserting twist separately into individual fibers or yarns, plying the fibers or yarns by inserting plying twist, setting the ply structure without permanently binding together the fibers or yarns of different plies so that the ply structure is substantially stable against untwist when torsionally untethered, and then unwrapping the plied fibers or yarns so that a high-spring-index fiber or yarn can be obtained. In some embodiments, the unwrapped fibers or yarns are further set so that these are further stabilized. The methods can eliminate the need for a mandrel, and can be quickly applied for applications where high-spring-index thermally-driven artificial muscles are presently employed, such as for presently commercialized comfort-adjusting jackets.

Abstract: Sheath-run artificial muscles (or SRAMs) are described in which the dimensional changes and/or modulus changes of a sheath on the surface of a twisted or coiled host yarn or fiber drives torsional and tensile actuation. The sheath-core artificial muscle includes a sheath on a coiled core yarn or fiber that has inserted twist, in which the sheath does not include a yarn, the coiled core yarn or fiber includes a core yarn or fiber, the sheath can change volume, modulus, or a combination thereof when actuated by an influence source to drive actuation, and the influence source is selected from a group consisting of absorption processes, desorption processes, changes in temperature, changes in external pressure, changes in a magnetic field, changes in an electric field, exposures to actinic radiation, electrochemical charge and discharge, chemical reactions, and combinations thereof.

Abstract: A smart (intelligent) textile that can control its porosity, shape, texture, loft, stiffness, or color by temperature change or moisture absorption by using polymer fiber torsional and tensile actuators. This temperature change can be due to a change in ambient temperature or by an external stimulus, such as electrothermal heating.

Abstract: Cooling by a twist-untwist process, by a stretch-release process for twisted, coiled, or supercoiled yarns or fibers, and methods and systems thereof. High mechanocaloric cooling results from release of inserted twist or from stretch release for twisted, coiled, or supercoiled fibers, including natural rubber fibers, NiTi wires, and polyethylene fishing line. Twist utilization can increase cooling and cooling efficiencies. A cooler using twist insertion and release can be shorter and smaller in volume than a cooler that requires a large elastomeric elongation. The cooler system can be utilized in mechanochromic textiles and remotely readable tensile and torsional sensors.

Abstract: Previous electrochemically-powered yarn muscles cannot be usefully operated between extreme negative and extreme positive potentials, since strokes during electron injection and during hole injection partially cancel because they are in the same direction. Unipolar-stroke carbon nanotube yarn muscles are described in which muscle strokes are additive between extreme negative and extreme positive potentials, and stroke increases with potential scan rate. These electrochemical artificial muscles include an electrically conducting twisted or coiled yarn and a material that dramatically shifts the potential of zero charge of the electrochemically actuated yarn.

Abstract: Actuators (artificial muscles) comprising twist-spun nanofiber yarn or twist-inserted polymer fibers generate actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize polymer fibers non-coiled or coiled yarns and can be either neat or comprising a guest. Devices comprising these artificial muscles are also described. In some embodiments, thermally-powered polymer fiber torsional actuator has a twisted, chain-oriented polymer fiber that has a first degree of twist at a first temperature and a second degree of twist at a second temperature in which the bias angles of the first degree and second degree of twist are substantially different.

Abstract: Sheath-run artificial muscles (or SRAMs) are described in which the dimensional changes and/or modulus changes of a sheath on the surface of a twisted or coiled host yarn or fiber drives torsional and tensile actuation. The sheath-core artificial muscle includes a sheath on a coiled core yarn or fiber that has inserted twist, in which the sheath does not include a yarn, the coiled core yarn or fiber includes a core yarn or fiber, the sheath can change volume, modulus, or a combination thereof when actuated by an influence source to drive actuation, and the influence source is selected from a group consisting of absorption processes, desorption processes, changes in temperature, changes in external pressure, changes in a magnetic field, changes in an electric field, exposures to actinic radiation, electrochemical charge and discharge, chemical reactions, and combinations thereof.

Abstract: Actuators (artificial muscles) comprising twisted polymer fibers generate tensile actuation when powered thermally. In some embodiments, the thermally-powered polymer fiber tensile actuator can be incorporated into an article, such as a textile or garment.

Abstract: Actuators (artificial muscles) comprising twist-spun nanofiber yarn or twist-inserted polymer fibers generate actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize polymer fibers non-coiled or coiled yarns and can be either neat or comprising a guest. Devices comprising these artificial muscles are also described. In some embodiments, thermally-powered polymer fiber torsional actuator has a twisted, chain-oriented polymer fiber that has a first degree of twist at a first temperature and a second degree of twist at a second temperature in which the bias angles of the first degree and second degree of twist are substantially different.

Abstract: Superelastic conductive fibers, and more particularly, sheath-core fibers for superelastic electronics, sensors, and muscles, and a process for fabricating of highly stretchable sheath-core conducting fibers by wrapping fiber-direction-oriented conductive nanofiber sheets on stretched rubber fiber cores.

Abstract: Actuators (artificial muscles) comprising twist-spun nanofiber twist-inserted polymer fibers generate tensile actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize coiled polymer fibers and can be either neat or comprising a guest. In some embodiments, the coiled polymer fibers actuator can be incorporated into an article, such as a textile, braid, clothing, smart packaging, or a mechanical system, and the coiled polymer fiber in the coiled polymer fiber actuator can have a stroke amplification factor of 5 or greater.

Abstract: Actuators (artificial muscles) comprising twist-spun nanofiber yarn or twist-inserted polymer fibers generate torsional actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize coiled yarns/polymer fibers and can be either neat or comprising a guest. In some embodiments, the actuator system includes a twisted and coiled polymer fiber actuator, and at least one of (i) wire connections that enable electrical heating of the twisted and coiled polymer fiber actuator, (ii) a radiation source and radiation pathway that enables photothermal heating of the twisted and coiled polymer fiber actuator, and (iii) a delivery system for delivering chemicals whose reaction produces heating of the twisted and coiled polymer fiber actuator.

Abstract: Yarn energy harvesters containing conducing nanomaterials (such as carbon nanotube (CNT) yarn harvesters) that electrochemically convert tensile or torsional mechanical energy into electrical energy. Stretched coiled yarns can generate 250 W/kg of peak electrical power when cycled up to 24 Hz, and can generate up to 41.2 J/kg of electrical energy per mechanical cycle. Unlike for other harvesters, torsional rotation produces both tensile and torsional energy harvesting and no bias voltage is required, even when electrochemically operating in salt water. Since homochiral and heterochiral coiled harvester yarns provide oppositely directed potential changes when stretched, both contribute to output power in a dual-electrode yarn.

Abstract: A smart (intelligent) textile that can control its porosity, shape, texture, loft, stiffness, or color by temperature change or moisture absorption by using polymer fiber torsional and tensile actuators. This temperature change can be due to a change in ambient temperature or by an external stimulus, such as electrothermal heating.