Miniaturizing engines and machines to sizes less than a few millimetres remains an unmet challenge because of the complexity of their design and their fundamental physics that does not favor down-sizing. Materials that respond like muscles by changing their shape or size on demand offer an alternative way to power miniature devices and this project seeks to mimic biological systems to generate artificial muscles suitable for use in robots, prosthetics and miniature devices.

The ideal artificial muscle generates large and reversible movements, develops useful forces, responds quickly, operates efficiently and lasts for many millions of cycles. All of these goals are yet to be achieved in a single artificial muscle material and many researchers world-wide are seeking a solution to this challenge.

Our work has taken inspiration from nature to develop artificial muscles with improved performance. By adopting composite structures found in wood, we have made fibers that respond to stimuli in a process called supercoiling. This phenomenon also occurs in DNA molecules and is involved in the packing of long DNA strands into the tiny cell nucleus. Our supercoiling muscles can contract to just 10% of their starting length and generate more than 30 times the mechanical work of natural muscle. We have adapted these muscles to prototype miniature tools that could be used in non-invasive surgery.

Tags: Soft Robotics, Artificial Muscles