New muscles for nanorobots

UNIVERSITY OF WOLLONGONG

Image shows the tail region and insides of a futuristic microbot with the flagella-like tail, rotated by a length of the new carbon nanotube yarn torsional muscles. Image: University of Wollongong The possibility of a doctor using tiny robots in your body to diagnose and treat medical conditions is now one step closer to becoming reality thanks to research led by a team from the University of Wollongong. The development of artificial muscles small and strong enough to push the tiny Nanobots along has just been published in the journal, Science. Although Nanorobots (Nanobots) have received much attention for the potential medical use in the body, such as cancer fighting, drug delivery and parasite removal, one major hurdle in their development has been the issue of how to propel them along in the bloodstream. An international collaborative team led by researchers at UOW’s Intelligent Polymer Research Institute (IPRI), part of the ARC Centre of Excellence for Electromaterials Science (ACES), has developed a new twisting artificial muscle that could be used for propelling nanobots. The muscles use very tough and highly flexible yarns of carbon nanotubes (nanoscale cylinders of carbon), which are twist-spun into the required form. When voltage is applied, the yarns rotate up to 600 revolutions a minute, then rotate in reverse when the voltage is changed. Due to their complexity, conventional motors are very difficult to miniaturise, making them unsuitable for use in nanorobotics. “The twisting artificial muscles, on the other hand, are simple and inexpensive to construct either in very long, or in millimetre lengths,” according to ACES Chief Investigator, Professor Geoff Spinks. “This new, giant, rotating type of actuation will open up lots of new opportunities for micro-machines,” he said. Professor Spinks said the tiny artificial muscles can twist like those in the trunk of an elephant or the arm of an octopus. “In these appendages, helically wound muscle fibres rotate by contracting against an incompressible, bone-less core. The rotation in the helically wound carbon nanotubes used for the twisting artificial muscles is caused by an increase of liquid electrolyte volume within the yarn, Professor Spinks said. The research team working on this project includes Professor Spinks, Dr Javad Foroughi (Research Fellow with IPRI) and Professor Gordon Wallace (IPRI Director and the Executive Research Director of ACES). It also involves researchers from the University of Texas, Hanyang University and the University of British Columbia. Professor Wallace said the exciting breakthrough has been made possible through the tremendous efforts of a team of multidisciplinary researchers working from four different countries over a sustained period of time. “ACES continues to attract important collaborative research linkages with leading groups around the world and this is critical to maintain our position at the leading edge of scientific research,” Professor Wallace said. Editor's Note: Original news release can be found here.