The University of Texas System

Industry-university Cooperation Foundation Hanyang University

Shaoli Fang

Ray H Baughman

Carter Sebastian Haines

Anvar A Zakhidov

Na Li

Marcio Dias Lima

Mikhail E Kozlov

Ali E Aliev

Mei Zhang

Sergey Li

Chris Williams

Kenneth Ross Atkinson

Jiyoung Oh

Dongseok Suh

Monica Jung DeAndrade

Raquel Ovalle-Robles

Mohammad H Haque

Jiuke Mu

Xavier N Lepro-Chavez

Javier Carretero-Gonzalez

Monica Jung De Andrade

Elizabeth Castillo-Martinez

David Michael Novitski

Chihye Lewis-Azad

Hongbing Lu

Zhong Wang

Zunfeng Liu

Jiangtao Di

Seon Jeong Kim

Shi Hyeong Kim

Changsoon Choi

Keon Jung Kim

Tae Jin Mun

Marco D Lima

Dong Qian

Run Wang

Fatma Göktepe

Özer Göktepe

Hetao Chu

Francisco A Moura

Jinsong Leng

Xinghao Hu

Fatma Goktepe

Nan Jiang

Xavier N Lepro

Ozer Goktepe

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.

Thermally-powered polymer fiber actuators and articles including same

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.

Unipolar artificial muscles and methods of use thereof

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.

Thermally-powered polymer fiber tensile actuators and articles including same

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. These sheath-run muscles can be used for diverse applications, such as robots, robotic devices, energy harvesters, muscles that enable electrical energy harvesting, comfort-adjusting textiles, comfort-adjusting clothing, bio-powered intelligent muscles that control the release of drugs, muscles for appropriate drug delivery, intelligent muscles that sense their environment and actuate in response, muscles for artificial limbs and orthotic gloves, muscles for haptic applications, muscles that can perform in extreme environments, and muscles for intelligent solar panel positioning.

Sheath-run artificial muscles and methods of use thereof

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. Mechanisms to accomplish this include (a) direct actuation (contraction or expansion) of polymer fiber actuators in a textile structure (b) rotation of polymer fiber actuators helically wrapped around warp and/or weft yarns in a textile structure; (c) rotation of chenille type or ribbon-like warp (or weft) ends by polymer fiber torsional actuators; (d) contraction or expansion of piles or loops in a chenille type fancy yarn produced by using mandrel actuators as pile or loop part of the yarn; (e) buckling of warp (or weft) yarns by contraction of tensile polymer fiber actuators; (f) decrease in yarn diameter by a twisting effect of polymer fiber actuators; (g) contraction or expansion of segmented mandrel actuators with core filament, wire or yarns; or (h) rotation of differentially dyed polymer fiber actuators for color changing textiles.

Actuating textiles containing polymer fiber muscles

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.

Methods for torsional refrigeration by twisted, coiled, and supercoiled fibers and systems thereof

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.

Polymer fiber actuators

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.

Sheath-core fibers for superelastic electronics, sensors, and muscles

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.

Thermally-powered coiled polymer fiber tensile actuator system and method

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.

Coiled and twisted nanofiber yarn and polymer fiber actuators

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. These energy harvesters were used in the ocean to harvest wave energy, combined with thermally-driven artificial muscles to convert temperature fluctuations to electrical energy, sewn into textiles for use as self-powered respiration sensors, and used to power a light emitting diode and to charge a storage capacitor.

Coiled and twisted nanofiber yarns for electrochemically harvesting electrical energy from mechanical deformation

The described incandescent tension annealing processes involve thermally annealing twisted or coiled carbon nanotube (CNT) yarns at high-temperatures (1000&#xb0; C. to 3000&#xb0; C.) while these yarns are under tensile loads. These processes can be used for increasing yarn modulus and strength and for stabilizing both twisted and coiled CNT yarns with respect to unwanted irreversible untwist, thereby avoiding the need to tether torsional and tensile artificial muscles, and increasing the mechanical loads that can be moved by these muscles.

Incandescent tension annealing processes for strong, twist-stable carbon nanotube yarns and muscles

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 torsional fiber actuator includes a first polymer fiber (exhibiting a first polymer fiber diameter) and a torsional return spring in communication with the first polymer fiber. The first polymer fiber is configured to include a first plurality of twists in a first direction to produce a twisted polymer fiber. The first polymer fiber is further configured to include a plurality of coils in the twisted polymer fiber in a second direction each coil having a mean coil diameter. In some embodiments, the torsional nanofiber actuator includes a first carbon nanofiber yarn (having a yarn diameter) and a torsional return spring in communication with the first carbon nanofiber yarn. The first carbon nanofiber yarn includes a plurality of twists in a first direction to produce a twisted carbon nanofiber yarn. The first carbon nanofiber yarn further includes a plurality of coils in the twisted carbon nanofiber yarn, with each coil having a mean coil diameter greater than the yarn diameter.

Coiled, twisted nanofiber yarn and polymer fiber torsional actuators

A nanofiber yarn that includes a plurality of nanofibers twisted into a yarn along an alignment axis. The nanofibers of the plurality of nanofibers have a ratio of nanofiber length to nanofiber circumference of at least 50. The yarn has a helix angle measured relative to the alignment axis of from 5&#xb0; to 30&#xb0;. The yarn has tensile strength of at least 280 MPa. A nanofiber fabric that includes a first sheet of multiwalled nanotubes and a second sheet of multiwalled nanotubes on the first sheet of multiwalled nanotubes. The multiwalled nanotubes of the first sheet are aligned in a first direction. The multiwalled nanotubes of the second sheet are aligned in the first direction. The first sheet and the second sheet are aligned so that the multiwalled nanotubes of the first sheet and the second sheet are both aligned in the first direction.

Fabrication and application of nanofiber ribbons and sheets and twisted and non-twisted nanofiber yarns

A process of producing a yarn, ribbon or sheet that includes nanofibers in which the process includes forming a yarn, ribbon or sheet comprising nanofibers, and applying an enhancing agent comprising a polymer to the yarn, ribbon or sheet.

Growing community of inventors

Richardson, TX, United States of America

Shaoli Fang