The humble fishing line may soon be used to provide the "muscle" for robots, prosthetic limbs and active garments thanks to a University of Wollongong breakthrough.
Researchers from the university's ARC Centre of Excellence for Electromaterials Science have worked with collaborators across six countries to turn fishing line into artificial muscles that are 100 times stronger than the real thing.
Lead Australian researcher Professor Geoff Spinks said the team had spent 15 years working on artificial muscles using sophisticated materials like carbon nanotubes.
The irony, he said, was they had now found that the best performing systems could be made from common fishing line.
"When you overtwist fishing line, with an electric drill or other motor, it starts to form tight coil structures," Prof Spinks said.
"Keep twisting and more coils form and it becomes like a spring, and then we use heat to set it. After this we cool it down and it expands, but if heat is again applied it contracts. In this way it can be used as an artificial muscle by applying heat."
Prof Spinks said applications for artificial muscles were constantly emerging.
"We're developing these materials for applications for devices where you need movement or force but you don't have much space," he said.
"If you've got plenty of space, like in a motor car, then you can have a big engine. But when you're getting into confined spaces, like portable devices you've got to carry around or clothing where you want movement, then these artificial muscles could be the replacement technology.
"Because fishing line is cheap and readily available, it's going to open up new opportunities."
As well as robotics and prosthetics, Prof Spinks said fishing line could be woven into fabric to produce active garments for use in the sports or health arenas.
"For instance, [at UOW] we are working on the lymph sleeve project as a possible treatment for people with lymphoedema.
"We are using artificial muscle to develop a massage sleeve that's comfortable and lightweight but which can constrict and expand to cause a massaging effect to drain away the lymph fluid."
Science journal has today published a paper on the breakthrough.