American scientists have created artificial muscle fibers from ordinary fishing line

Today, February 21, the journal Science published an article about a fundamentally new way of creating artificial muscles, based on the usual fishing line and other similar polymeric threads, without using expensive or exotic materials like carbon nanotubes, vanadium dioxide or metal alloys with memory . Moreover, the method of their manufacture is completely trivial and is available at home - the line twists under load until it coils into a spiral, and then it heats up. When heated, the spiral is reduced, developing a large enough force, during cooling it is extended to its original size.



Artificial muscle fiber from nylon can be reduced by 49% relative to the initial length and raise the weight, a hundred times larger than human muscle fibers of the same thickness and length. Its specific mechanical power reaches 5.3 kilowatts per kilogram - this is comparable with jet engines of aircraft and the most advanced modern electric motors.

The speed of such a muscle depends primarily on how quickly it can cool and heat. In addition to experiments with a heat gun and passive air cooling, the scientists investigated the operation of fibers in water and in helium atmosphere (it has a very high thermal conductivity). In such conditions, it was possible to achieve a frequency of contractions of several hertz:
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Such fibers can also be woven into a fabric, or weave nets and bundles from them that can shrink in response to a control signal or a change in external conditions. This video shows how a piece of fabric with 0.45 mm nylon fibers woven into it lifts a load of 3 kg. In this experiment, the fibers were heated by passing a wire through wires inside the nylon coils, rather than using a heat gun.



The article itself with a description of technology and experiments is available on the website of Science magazine only for a fee, but you can download highly detailed additional materials and videos for free .