Artificial muscles have been recently getting a lot more effective thanks to a small but significant addition.

Over the past 15 years, engineers around the world have developed artificial muscles from a range of materials – some high-tech and expensive and some as simple as yarn or fishing line.

Now, researchers from the University of Wollongong (UOW) have started encasing them in sheaths – a simple change that gives the technology 40 times more flex than a human muscle.

“Previously, we were applying energy to the entire muscle, but only the outer part of the fibre was responsible for actuation,” said Senior Professor Geoffrey Spinks, who worked on the technology at UOW’s Intelligent Polymer Research Institute.

“By placing a sheath on the muscle, we can focus only that energy on the outer part of the fibre and convert this input energy more quickly and efficiently.”

This allows the technology to be used for a wide variety of applications, from responsive garments to artificial hearts.

“Or, for example, drug delivery applications,” suggested Senior Research Fellow Dr Javad Foroughi, who led the research in Australia.

“We can utilise this muscle as a smart drug delivery system for controlled delivery of chemotherapeutic drugs locally to the tumour sites. You have some encapsulated drugs inside the body, and we need some time to open it to release the drug … we can implant it with this sort of muscle, [and it] has the ability to control or program this device.”

The same approach can be adopted to control an artificial heart that can be used during surgery, Foroughi told create.