# US 11,299,825 B2 · Manufacturing of artificial muscle actuators > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,825 B2 - Document ID: US11299825B2 - Status: Granted - Kind: B2 - Application number: 16/488,970 - Filed: 2018-02-27 - Published: 2020-01-02 - Granted: 2022-04-12 - Earliest claimed: 2017-02-28 - Assignees: Lintec of America, Inc. - Applicants: Lintec of America, Inc. - Inventors: Marcio Dias Lima; Sergey Li - Web page: https://patentgrep.com/patent/US11299825B2 ## CPC - D02J 13/001: {in a tube or vessel} - A61F 2/08: Muscles; Tendons; Ligaments - D01F 8/12: with at least one polyamide as constituent - D01F 8/18: from other substances - D02J 1/18: Separating or spreading - F03G 7/0121: {Electroactive polymers} - F03G 7/029: {characterised by the material or the manufacturing process, e.g. the assembly} - F03G 7/0612: {using polymers} - F03G 7/0633: {performing a rotary movement} - D02G 1/02: by twisting, fixing the twist and backtwisting, i.e. by imparting false twist - D02J: FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE (curling or crimping D02G; by treatment with liquids, gases or vapours D06B; finishing other than by liquid treatment, of yarns in warp or sheet form D06C; for chemical matters, see D06L, D06M, D06P, D06Q; treatment during rope-making, apparatus for treating ropes auxiliary to rope-making D07B) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS - 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) - D02G: CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS ## Abstract Methods and a device for the continuous manufacturing of artificial muscle actuator device fibers are disclosed. The method includes: threading an untwisted fiber along the axis of a tube and inside the tube that includes a heating means to raise the localized temperature of a cross-section of the tube to a predetermined temperature; providing a tension on the untwisted fiber; and twisting the untwisted fiber while the fiber is within the tube. ## Claims ### Claim 1 A method of manufacturing an artificial muscle actuator fiber, the method comprising: providing a tube having one or more continuous heating sections along a length of the tube; and in a continuous process, threading an untwisted fiber along the axis of the tube and inside the tube from a first end of the tube towards and passing an opposite second end of the tube; providing a tension on the untwisted fiber; twisting the untwisted fiber while the fiber is within the tube by applying a rotational force to the untwisted fiber such that the fiber is continuously twisted at a twisting point that is intermediate the first end of the tube and the opposite second end of the tube, advancing twists, formed by twisting the previously untwisted fiber, towards the opposite second end of the tube, wherein the tube is configured to prevent snarling during the twisting of the untwisted fiber, providing an inner diameter of the tube to be 10% to 20% larger than a diameter of the untwisted fiber, and wherein the tube is further provided as a heater to raise the localized temperature of a cross-section of the tube to a predetermined temperature. ### Claim 2 (depends on 1) The method of claim 1, wherein the predetermined temperature is selected to be between the glass transition temperature of the fiber and the melting temperature of the fiber. ### Claim 3 (depends on 1) The method of claim 1, wherein the untwisted fiber comprises a polymer fiber selected from the group consisting of Nylon 6, Nylon 6,6, polyethylene, polyvinylidene fluoride, Nylon 6,10, Nylon 6,12, liquid crystalline polymers, polyarylate, and combinations thereof. ### Claim 4 (depends on 1) The method of claim 1, wherein the untwisted fiber comprises carbon nanotubes (CNT). ### Claim 5 (depends on 1) The method of claim 1, further comprising: applying a coating to the twisted or untwisted fiber. ### Claim 6 (depends on 1) The method of claim 1, further comprising: applying a coating to the fiber while the fiber is inside the tube. ### Claim 7 (depends on 1) The method of claim 1, further comprising: removing moisture from the untwisted fiber prior to threading the untwisted fiber along the axis of the tube. ### Claim 8 (depends on 1) The method of claim 1, further comprising: supplying an inert gas inside the tube. ### Claim 9 (depends on 1) The method of claim 1, further comprising: supplying a lubricant inside the tube during the twisting. ### Claim 10 (depends on 1) The method of claim 1, further comprising: threading the twisted fiber along an axis of a second tube, wherein the second tube comprises a second heater to raise the temperature of a cross-sectional area of the second tube to a second predetermined temperature. ### Claim 11 (depends on 10) The method of claim 10, wherein the second predetermined temperature is greater than the predetermined temperature. ### Claim 12 (depends on 1) The method of claim 1, wherein the tube has a plurality of heating sections; and, in a direction from the first end of the tube towards the opposite second end of the tube, a diameter of a heating section of the tube is larger than a diameter of any preceding section of the tube. ### Claim 13 (depends on 12) The method of claim 12, wherein the twisting of the untwisted fiber forms a coiled fiber inside the heating section of the tube that has a larger diameter than a preceding section of the tube.