Supercoiling Artificial Muscles

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An example of supercoiling in the artificial muscles (right), compared to the looser twist (left)
An example of supercoiling in the artificial muscles (right), compared to the looser twist (left)
Geoff Spinks

Tiny robots could serve all kinds of useful functions, but shrinking their actuators has proven challenging. Now researchers at the University of Wollongong (UOW) in Australia have made artificial muscles that surpass your puny natural ones, inspired by the “supercoiling” of DNA strands.

DNA performs one of nature’s most impressive feats of contraction, cramming strands about 2 m (6.6 ft) long into a single human cell. To do so, DNA makes use of a process called supercoiling – essentially, if you twist two fibers together and keep going after they’ve wound completely around each other, they will deal with the extra force by buckling out to the side. Besides DNA, you can see this supercoiling effect in everything from a tangled garden hose to the wires of your earbuds.

For the new study, the UOW scientists set out to replicate this phenomenon in their artificial muscles. They made them out of composite polyester fibers, coated in a hydrogel that swells up when it gets wet. These were twisted together into the familiar helix shape of DNA, then immersed in water to get them to swell up.

Normally this swelling would cause the fibers to unravel, but the team found that if they clamped the ends the fibers undergo supercoiling instead. As such, they contract upwards, generating a relatively large amount of mechanical force.

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About the Common Constitutionalist

Brent, aka The Common Constitutionalist, is a Constitutional Conservative, and advocates for first principles, founders original intent and enemy of progressives. He is former Navy, Martial Arts expert. As well as publisher of the Common Constitutionalist blog, he also is a contributing writer for Political Outcast, Godfather Politics, Minute Men News (Liberty Alliance), Freedom Outpost, the Daily Caller, Vision To America and Free Republic. He also writes an exclusive weekly column for World Net Daily (WND).