Miniature Devices Recognised on The Global Stage

Source: Sally Wood

Geoff Spinks, Senior Professor, Australian Institute for Innovative Materials, University of Wollongong. Image credit: University of Wollongong.

Researchers are developing the next generation of non-invasive surgery or robotic surgical systems, which is matching the performance of a natural muscle using artificial muscles created in the lab. The systems include miniature tweezers, prosthetic hands or dexterous robotic devices. University of Wollongong (UoW) researcher Senior Professor Geoff Spinks is a world-leader in artificial muscle material research and the development of artificial muscles in miniature devices, which could be applied in medicine and robotics. “We were investigating microfibres made from hydrogel materials when we happened upon the supercoiling behaviour. It was then that we realised that our fibres were mimicking DNA folding,” Professor Spinks said. Alongside an international research team, Professor Spinks has developed various types of artificial muscles in the past that bend, rotate or contract in length. The science has enabled the research team to make artificial muscles as thin fibres or films that are especially well suited to microscopic devices. Artificial muscle materials are useful where space is limited. For example, the latest motor-driven prosthetic hands do not currently match the dexterity of a human hand. As such, more actuators are needed to replicate the full range of motion grip types and strength of a healthy human. The most recent breakthrough happened as an unexpected outcome for the researchers. “The double helix of DNA is one of the most iconic symbols in science. By imitating the structure of this complex genetic molecule, we have found a way to make artificial muscle fibres far more powerful than those found in nature, with potential applications in many kinds of miniature machinery such as prosthetic hands and dexterous robotic devices,” Professor Spinks explained. As a result of this discovery, the fibre shrank by up to 90 per cent of its original length. However, when compared to a human muscle, the supercoiling fibre is shown to be 30 times smaller in diameter. The muscle fibres of mammals only shrink by about 20 per cent of their original length and produce a work output of 0.03 joules per gram. “Our discovery offers an exciting new type of high-performance fibres that contract just like our own muscles. These fibres can be easily attached to miniature machines like tools for robotic surgery,” Professor Spinks said. A number of prototypes have already been developed including robotic fish, a micromixer of fluids and using supercoiling muscle fibres to open and close miniature tweezers. “We still have much to do to turn our discovery into practical devices and we are currently working to solve these remaining issues,” he said. Professor Spinks was recently recognised as one of ten global winners for Science Breakthrough of the Year 2021. The awards were celebrated in Berlin last November at the prestigious Falling Walls Science Summit, which is a leading forum for scientific breakthroughs and science dialogue between global science leaders and society. Professor Spinks said it was an honour to have his research recognised on the global stage. “The Falling Walls Foundation is doing a fantastic job at promoting advances in all fields of endeavour to a massive global audience. It’s a great honour to be recognised by such a prestigious organisation,” he said. The Falling Walls Science Breakthroughs of the Year takes place on the anniversary of the historic fall of the Berlin Wall on 9 November.

DNA-inspired 'supercoiling' fibres could make powerful artificial muscles for robots. Image credit: University of Wollongong.