Science fiction has suggested artificial limbs stronger than biological counterparts. We are beginning to see this reality in present day research. “Carbon-nanotube-based muscles that are 100 times stronger than natural muscle” have already been produced by the research of Ray Baughman, director of the Nanotech Institute at the University of Texas at Dallas. Now, he has produced a yarn from carbon nanotubes that can twist 1000 times more than other materials. It is this twisting motion that opens new possibilities and gives the material a potential as strong as a commercial electric motor.
What can they do?
Small-sized nanotech muscles may be useful in some of the tiniest applications, where electrical energy is turned into mechanical energy. Normally, we think of artificial muscles like electrical devices that produce the linear motion solenoids and actuators. These new materials have a much wider operating range than devices we now use. Some of them use fuel rather than electricity as an energy supply. Some are as light as air.
Artificial muscles are also potentially useful in devices that mimic nature; robotics (such as vehicles that stay aloft by flapping wings) and as potential replacements for damaged human muscles like the heart. Due to their wide temperature range, space and exploration also include possible applications. This is “game changing” potential.
How do they do it?
Electricity and an electrolyte were used for this effect to take place on the carbon nanotubes:
To create the twisting motion, the yarn is connected to an electrode and immersed in an electrolyte. Ions from the electrolyte enter the yarn, which causes it to first swell and then contract and rotate along its length.
Issues and comments:
“This is a fascinating new way to provide torsion,” says Baughman. What remains to be disclosed is the relative energy cost and efficiency of this material/device. This would give us a benchmark for comparison with present technology, and allow us to evaluate utility and future improvement.
Primary source: MIT Technology Review
Photo Credit: NASA