Coiled actuator system and method
A method of generating a coiled actuator fiber that includes twisting a fiber to generate a twisted fiber; wrapping the twisted fiber around a core yarn or fiber to generate a coil in the twisted fiber, which generates a coiled twisted fiber; setting the coiled twisted fiber by heat or chemical treatment; and removing at least a portion of the core yarn or fiber to generate a coiled actuator fiber.
1. A method of generating a coiled actuator fiber comprising:
twisting a fiber to generate a twisted fiber;
wrapping the twisted fiber around a core yarn or fiber to generate a coil in the twisted fiber, which generates a coiled twisted fiber;
setting the coiled twisted fiber by heat or chemical treatment; and
removing at least a portion of the core yarn or fiber to generate a coiled actuator fiber.
2. The method of claim 1 , wherein at least a portion of the core yarn or fiber is removed through at least one of the following:
(a) dissolution;
(b) chemical reaction; and
(c) melting.
3. The method of claim 1 , wherein the direction of the wrapping is the same as the direction of the twisting.
4. The method of claim 1 , wherein the direction of the wrapping is the opposite of the direction of the twisting.
5. The method of claim 1 , wherein setting the coiled twisted fiber is carried out prior to the removing at least a portion of the core yarn or fiber to generate the coiled actuator fiber.
6. The method of claim 1 , wherein the coiled actuator fiber comprises a coil spring index (C) greater than 1.7.
7. The method of claim 1 , wherein the coiled actuator fiber comprises a thermal expansion coefficient having a magnitude of 1000 μm/m/K or more.
8. The method of claim 1 , wherein space between neighboring coils of the coiled actuator fiber is such that thermal actuation of the coiled actuator fiber in an unloaded state brings the neighboring coils into contact with each other above 10° C.
9. A method of constructing a thermally adaptive fabric comprising the method of claim 1 and further including:
generating a thermally adaptive fabric including a plurality of coiled actuator fibers generated by at least a portion of the method of claim 1 , wherein the coiled actuator fiber is at least partially responsible for thermal adaptation of the thermally adaptive fabric.
10. The method of claim 9 , wherein the removing the at least a portion of the core yarn or fiber occurs after generating a thermally adaptive fabric including the plurality of coiled actuator fibers generated by at least the portion of the method of claim 1 .
11. The method of claim 9 , wherein a thermal adaptation of the thermally adaptive fabric causes the thermally adaptive fabric to increase insulation capability of the thermally adaptive fabric in response to a decrease in temperature of an ambient environment that the thermally adaptive fabric is present in.
12. The method of claim 9 , wherein the thermally adaptive fabric is generated through weaving or knitting.
13. The method of claim 9 , wherein the plurality of coiled actuator fibers comprise a thermal expansion coefficient having a magnitude of 1000 μm/m/K or more.
14. The method of claim 9 , wherein the plurality of coiled actuator fibers comprise a thermal expansion coefficient of having a magnitude of 2 mm/m/° C. or more.
15. A method of constructing a thermally adaptive garment comprising the method of claim 1 and further including:
generating a thermally adaptive garment including a plurality of coiled actuator fibers generated by at least a portion of the method of claim 1 , wherein the plurality of coiled actuator fibers are at least partially responsible for thermal adaptation of the thermally adaptive garment.
16. The method of claim 15 , wherein the thermal adaptation of the thermally adaptive garment causes the thermally adaptive garment to increase insulation capability of the thermally adaptive garment in response to a decrease in temperature of an ambient environment that the thermally adaptive garment is present in.
17. A method of generating a coiled actuator fiber comprising:
twisting a fiber to generate a twisted fiber;
coiling the twisted fiber to generate a coiled fiber; and
setting the coiled fiber by heat or chemical treatment to generate a coiled actuator fiber,
wherein the coiled actuator fiber comprises a thermal expansion coefficient having a magnitude of 2 mm/m/° C. or more, and
wherein the coiled actuator fiber defines space between neighboring coils of the coiled actuator fiber such that thermal actuation of the coiled fiber actuator brings the neighboring coils into contact with each other above 10° C.
18. The method of claim 17 , wherein the coiled fiber is physically constrained during the setting such that a temperature change during the setting does not physically bring the neighboring coils into contact with each other based on the physical constraint of the neighboring coils.
19. A method of generating a coiled actuator fiber comprising:
generating a coiled actuator fiber having coils that define physical space between the coils when:
a. the coiled actuator fiber is at 27.0° C. and
b. is unloaded, and
setting the coiled fiber actuator by at least one of either:
a. heat or
b. chemical treatment,
while the coiled actuator fiber is under physical constraint that prevents actuation of the coiled actuator fiber during the setting.
20. The method of claim 19 , wherein the physical constraint is provided by a core yarn or fiber that prevents actuation of the coiled actuator fiber during the setting.