While people don’t think of aluminum as particularly heavy metal, it’s denser than one thinks in its conventional form—heavier even than water.
Now researchers in the United States and Russia have developed a theoretical model for creating aluminum that’s even lighter than water, which could give this type of metal unprecedented applications for use in electronics, medicine, and spaceflight.
A graphic shows the model for a new type of ultra-lightweight aluminum designed by researchers at the University of Utah and Southern Federal University in Russia. The aluminum in theory is lighter even than water. (Source: Alexander Boldyrev, Utah State University)
Utah State University (USU) chemist Alexander Boldyrev and his team used computational modeling to restructure the common household metal at the molecular level, which in theory produces an ultra-light crystalline form of aluminum, he said.
The discovery came while researchers—which also include scientists from Southern Federal University in Rostov-on Don, Russia—were trying to design new metastable materials in general, not specifically focusing on aluminum, Boldyrev, a professor in USU’s Department of Chemistry and Biochemistry, told Design News.
“We did not really try to design an ultra-light aluminum initially,” he said. “We used this trick [to] take the diamond lattice and substitute every carbon atom by a tetrahedral Al4 cluster, and we suddenly found that this new metastable superterahedral aluminum is extremely light.”
The resulting material, according to the model, has a density of only 0.61 gram per cubic centimeter, in contrast to convention aluminum’s density of 2.7 grams per cubic centimeter, according to researchers.
This means that “the new form of crystal aluminum, if experimentally made, should float in water,” which means a spoon made from it also will float, Boldyrev said. This property paves the way for an entirely whole new realm of possible applications for the non-magnetic, corrosive-resistant, abundant, and relatively inexpensive and easy-to-produce metal, he said.
Indeed, aluminum already is relatively cheap, and its production industry is quite well developed. “If we can find a cheap way to convert traditional aluminum into this ultra-light aluminum, it may find many application in areas such as aerospace, water transport, the auto industry, and electronics,” Boldyrev said.
Researchers published a paper on their work in The Journal of Physical Chemistry C.
While the possibilities for the aluminum appear to be many, Boldyrev said there is still much work to be done as well as many unanswered questions.
The first order of business, he said, is to actually make the aluminum, not just model it. “We have already invitations from experimentalists to start working on experimental realization of our ultra-light aluminum,” Boldyrev.
The method also can be applied to other materials, work the team also plans to continue, he added.
“We are theoreticians, and our goal is to test what is possible in chemistry and material science,” Boldyrev said. “We will continue to do our theoretical work hoping to find more new unusual materials with unpredictable properties.”
Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 15 years.