Australian researchers make powerful, tiny artificial muscles inspired by DNA “supercoiling”

University of Wollongong researchers have developed a new type of DNA-inspired artificial muscle, with potential applications in miniature robotics.

The UoW team’s paper, “Dual high-stroke and high–work capacity artificial muscles inspired by DNA supercoiling”, was published in Science Robotics. According to the university, it addresses the challenges of performance loss as actuators are made smaller and smaller, and borrows from the way DNA “supercoils” to fit inside a cell’s nucleus.

“Electric motors are simply too complicated to downsize, so we look to artificial muscles to provide compact mechanical actuation,” explained lead author, Professor Geoffrey Spinks (pictured.)

“Arrays of miniature artificial muscles could be combined to fabricate advanced prosthetics and wearable devices to help people move when they have a physical disability or injury. Tiny actuators can also be incorporated into tools for non-invasive surgery and micro-manipulators in industry.”

DNA contracts by as many as 1,000 times when fitting inside a nucleus.

“We were able to create DNA-like unwinding by swelling twisted fibres. Supercoiling occurred when the fibre ends were blocked against rotation,” added Spinks.

“We show that these new artificial muscles generate a large amount of mechanical work.”

The artificial muscles were successfully trialled in applications including micro-tweezers.

“We have learned that by forming fibre composites where the fibre is wound into a helix provides a convenient way to store and release mechanical energy,” said Dr Sina Naficy, a co-author on the paper and now at the University of Sydney.

“There are many examples of these kinds of helical composites in nature, from DNA molecules to plant tendrils. These systems offer exciting prospects for future developments.”

Picture: UoW

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