Nanotubes and crystals can improve efficiency of new technology and lead to new technologies.

Making really small things is more helpful than you think. Some new developments hold promise for artificial limbs, efficient hydrogen fuel cells, and space travel.

Small cubic zirconia crystals will greatly improve hydrogen fuel cells efficiency.

Fuel cells combine hydrogen fuel and oxygen from the air to release energy, leaving only water as a waste product. Fuel cells could be an alternative power source for vehicles and other uses, but there are significant challenges to their widespread use. Current fuel cells run at temperatures of 1,500 to 1,800 degrees F (800 to 1,000 degrees C). Just reaching working temperature requires energy, and the heat quickly wears out metal, plastic and ceramic components. Prevailing fuel-cell designs also require an expensive platinum catalyst.

The new technology could allow fuel cells to run at much lower temperatures, 122 to 212 degrees F (50 to 100 degrees C).

Munir, Umberto Anselmi-Tamburini and Sangtae Kim at UC Davis invented a method to make oxides such as cubic zirconia (zirconium oxide) with extremely small grain sizes, on the order of 15 nanometers. A nanometer is one-billionth of a meter, or the size of a few atoms. At that scale, the crystals conduct electricity very well, through the movement of protons. The material could be used in fuel cells that are based on chemical oxides.

Nanotubes can be used to build artificial muscles.

The discovery that nanotubes keep bouncing back after being compressed repeatedly means this exotic form of carbon may be just the thing to give artificial muscles some extra strength.

Engineers want to build artificial muscles – actuators that change length in response to a stimulus – because they create a smoother, more human-like motion than jerky electric motors or pneumatic devices. Such muscles would be used to power robots, prosthetic limbs and artificial tissue for implantation.

Today’s most promising artificial muscles are based on electroactive polymers (EAPs) – plastics that change shape when activated electrically or with chemicals. But they lack mechanical robustness and as a result soon succumb to fatigue and fail. Now engineers led by Victor Pushparaj at the Rensselaer Polytechnic Institute in Troy, New York, say that carbon nanotubes could toughen up artificial muscles.

These Carbon Nanotubes are the same ones being developed to build Space Elevators.

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