We Can Soon Make an Aluminum Lighter Than Water: A Material Design Breakthrough

Khryss | Published 2017-09-27 16:57

Aluminum is a cheap, non-magnetic, resistant to corrosion, extremely common, and easy-to-produce metal. It has a density of 2.7 grams per cubic centimetre--if you drop it on a container full of water, it would sink to the bottom. However, if you rearrange them in a certain way at the molecular level, it could actually become lighter than water.

This opens up a whole new range of possible uses for the material. “Spaceflight, medicine, wiring and more lightweight, more fuel-efficient automotive parts are some applications that come to mind,” Boldyrev says.

So, using computational modelling, researchers tried making a new, metastable, ultralight form of crystal aluminium. “My colleagues’ approach to this challenge was very innovative,” says Utah State University chemist Alexander Boldyrev.

“They started with a known crystal lattice, in this case, a diamond, and substituted every carbon atom with an aluminum tetrahedron.” The resulting material is so lightweight--its density is just 0.61 grams per cubic centimetre; so much lighter than the conventional form’s density.

“That means the new crystallized form will float on water, which has a density of one gram per cubic centimeter,” says Boldyrev. But since it was computationally made, its strength and durability is still unknown.

Nonetheless, this breakthrough gives a new way of how to approach material design. “An amazing aspect of this research is the approach: using a known structure to design a new material. This approach paves the way for future discoveries,” Boldyrev says. If they can do this to aluminium, what about other metals? Only time will tell.


Hey! Where are you going?? Subscribe!

Get weekly science updates in your inbox!