Artificial muscles no longer at arms length

Researchers from Monash University and The University of Woollongong have developed salt-based liquids that improve the performance of artificial muscles by thousands of times.

The discovery has progressed the development of artificial muscles to such an extent that simple prosthetic devices containing artificial muscles could be available within three years, said Professor Doug MacFarlane, from Monash University's chemistry department.

The researchers have spent five years developing 'ionic liquids' - salts that are liquid at room temperature - that have revolutionised the performance of artificial muscles.

Artificial muscles operate in the same way as a battery - with electrodes and an electrolyte. But the limited lifespan of these muscles has meant they can't be used in humans.

"The electrolyte in between the electrodes was, until recently, a relatively simple salt in a solvent," Professor MacFarlane said. "This meant that the expansion and contraction of the muscle did not last for long, it degraded and, ultimately, the electrolyte evaporated away."

However, the ionic liquids developed by Professor MacFarlane and his colleagues do not evaporate away and allow the contraction and expansion of artificial muscles to go on indefinitely.

Professor MacFarlane said that until now artificial muscles had been able to undergo no more than 10 cycles of expansion and contraction. However the ionic liquids he has developed have increased this to more than 100,000 cycles.

This advance will be used to create textiles that expand and contract and will also have applications in batteries and solar cells, Professor MacFarlane said.

"In the much longer term you can expect to see artificial muscles and limbs where you can cause whole limbs to move. At the moment you can only do that using a motor with gears, cogs and cables," he said.

Item provided courtesy of Monash University