# US 10,480,491 B2 · Coiled, twisted nanofiber yarn and polymer fiber torsional actuators

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- Number: US 10,480,491 B2
- Document ID: US10480491B2
- Status: Granted
- Kind: B2
- Application number: 15/814,941
- Filed: 2017-11-16
- Published: 2018-03-15
- Granted: 2019-11-19
- Earliest claimed: 2012-08-01
- Assignees: Board of Regents, The University of Texas System
- Applicants: Board of Regents, The University of Texas System
- Inventors: Na Li; Carter S. Haines; Marcio D. Lima; Monica Jung DeAndrade; Shaoli Fang; Jiyoung Oh; Mikhail E. Kozlov; Dongseok Suh; Ray H. Baughman
- Web page: https://patentgrep.com/patent/US10480491B2

## CPC

- H02N 11/006: {Motors}
- D01D 5/0007: {Electro-spinning (non-woven fabrics produced by electro-spinning D04H1/728)}
- D01F 6/00: Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01H 1/10: for imparting multiple twist, e.g. two-for-one twisting
- D02G 3/02: Yarns or threads characterised by the material or by the materials from which they are made
- D02G 3/26: with characteristics dependent on the amount or direction of twist
- D02G 3/448: {Yarns or threads for use in medical applications (D02G3/449 takes precedence; surgical suture materials A61L17/00)}
- D04C 1/02: made from particular materials
- F03G 7/06113: {the fluids subjected to phase change}
- F03G 7/0633: {performing a rotary movement}
- F03G 7/064: {characterised by its use}
- H02N 10/00: Electric motors using thermal effects {(motors using expansion or contraction of bodies due to heating or cooling F03G7/06)}
- D10B 2401/046: Shape recovering or form memory
- D10B 2401/061: elastic
- D10B 2509/00: Medical; Hygiene
- F03G 7/066: {Actuator control or monitoring}
- Y10T 428/249921: Web or sheet containing structurally defined element or component
- Y10T 428/2925: Helical or coiled
- H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01H: SPINNING OR TWISTING (twisting oakum D01G35/00; crimping or curling of fibres, filaments, or yarns D02G1/00)
- D02G: CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
- D04C: BRAIDING OR MANUFACTURE OF LACE, INCLUDING BOBBIN-NET OR CARBONISED LACE; BRAIDING MACHINES; BRAID; LACE (machines for making soles from strips of material A43D29/00; cane working B27J1/00)
- F03G: SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR (arrangements in connection with power supply in vehicles from force of nature B60K16/00; electric propulsion with power supply in vehicles from force of nature B60L8/00)
- D10B: INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## 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 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.

## Claims

### Claim 1

A torsional fiber actuator comprising:
(a) a first polymer fiber exhibiting a first polymer fiber diameter, the first polymer fiber configured to include
(i) a first plurality of twists in a first direction to produce a twisted polymer fiber, and
(ii) a plurality of coils in the twisted polymer fiber in a second direction each coil having a mean coil diameter, wherein
(A) the first plurality of twists and the plurality of coils in the first polymer fibers comprise a reversible torsional fiber actuating element; and
(b) a torsional return spring in communication with the first polymer fiber.

### Claim 2 (depends on 1)

The torsional fiber actuator of claim 1, wherein the first direction and the second direction are the same.

### Claim 3 (depends on 1)

The torsional fiber actuator of claim 1, wherein the first direction and the second direction are in opposite directions.

### Claim 4 (depends on 1)

The torsional fiber actuator of claim 1, wherein each coil of the plurality of coils has a mean coil diameter that is a mean of an inner coil diameter and an outer coil diameter that is no more than 1.7 times greater than the first polymer fiber diameter.

### Claim 5 (depends on 1)

The torsional fiber actuator of claim 1, wherein the torsional return spring comprises a second fiber plied with the first polymer fiber in a third direction opposite the first direction.

### Claim 6 (depends on 1)

The torsional fiber actuator of claim 1 further comprising:
(a) a second polymer fiber configured to include a second plurality of twists in the first direction, the second polymer fiber plied with the first polymer fiber in a third direction opposite the first direction to form a heterochiral plied yarn, and
(b) wherein the second polymer fiber is the torsional return spring.

### Claim 7 (depends on 1)

The torsional fiber actuator of claim 1 further comprising a conductor in contact with the first polymer fiber.

### Claim 8 (depends on 1)

The torsional fiber actuator of claim 1 further comprising a rotor connected to at least one of the first polymer fiber and the torsional return spring.

### Claim 9

A torsional nanofiber actuator comprising:
(a) a first carbon nanofiber yarn having a yarn diameter and comprising
(i) a plurality of twists in a first direction to produce a twisted carbon nanofiber yarn, and
(ii) a plurality of coils in the twisted carbon nanofiber yarn, each coil having a mean coil diameter greater than the yarn diameter, wherein
(A) the first plurality of twists and the plurality of coils in the first polymer fibers comprise a reversible torsional fiber actuating element; and
(b) a torsional return spring in communication with the first carbon nanofiber yarn.

### Claim 10 (depends on 9)

The torsional nanofiber actuator of claim 9 further comprising a guest in the first carbon nanofiber yard, the guest and the first carbon nanofiber yard forming a first hybrid yard.

### Claim 11 (depends on 10)

The torsional nanofiber actuator of claim 10, wherein
(a) the guest is capable of a volume change causing the first carbon nanofiber yarn to change from a non-actuated state to an actuated state,
(b) the volume change of the guest is at least 7.7%, and
(c) the volume change results in rotational torque of the first carbon nanofiber yarn.

### Claim 12 (depends on 10)

The torsional nanofiber actuator of claim 10, wherein the first hybrid yarn has a torsional actuation of from 71°/mm to 100°/mm.

### Claim 13 (depends on 10)

The torsional nanofiber actuator of claim 10, wherein the guest is wax.

### Claim 14 (depends on 10)

The torsional nanofiber actuator of claim 10, wherein the guest is polydiacetylene.

### Claim 15 (depends on 9)

The torsional nanofiber actuator of claim 9, wherein the torsional return spring comprises a segment of the carbon nanofiber yarn infiltrated with wax.

### Claim 16 (depends on 15)

The torsional nanofiber actuator of claim 15, wherein the torsional actuation comprises up to 30°/mm.

### Claim 17 (depends on 9)

The torsional nanofiber actuator of claim 9 further comprising a second yarn plied with the first carbon nanofiber yarn to form a two-ply heterochiral yarn.

### Claim 18 (depends on 17)

The torsional nanofiber actuator of claim 17, wherein the two-ply heterochiral yarn further comprises a wax infiltrant throughout the two-ply heterochiral yarn.

### Claim 19 (depends on 18)

The torsional nanofiber actuator of claim 18, wherein the torsional actuation is up to 30°/mm.

### Claim 20 (depends on 17)

The torsional nanofiber actuator of claim 17, wherein the two-ply heterochiral yarn further comprises a wax infiltrant within half of the two-ply heterochiral yarn.

### Claim 21 (depends on 20)

The torsional nanofiber actuator of claim 20, wherein the torsional actuation is up to 12.6°/mm.

### Claim 22 (depends on 9)

The torsional nanofiber actuator of claim 9, wherein the first carbon nanofiber yarn comprises a homochiral carbon nanofiber yarn, wherein a first half of the homochiral carbon nanofiber yarn comprises the plurality of twists and a second half of the homochiral carbon yarn is unactuated and comprises the torsional return spring.