Insights from BCC Research

The End of Heavy Metal: The World’s Lightest Material is No Weakling

Posted by Clayton Luz on Nov 24, 2015 6:00:00 AM

Researchers announced they have developed a material that is about one hundred times lighter than Styrofoam™. With a density of 0.9 mg/cc, meaning the material is 99.99% air, the material is the world’s lightest, they claim. Yet, it’s so strong they say an egg wrapped in the material would survive a 25-story drop.

The material, called a microlattice, redefines the limits of lightweight materials because of its unique cellular architecture.  The results of the study, a collaborative effort of HRL Laboratories, California Institute of Technology and University of California at Irvine, appears in the November 18 issue of Science.

Using an innovative fabrication process developed by HRL scientist Alan Jacobsen, Ph.D., the team was able to design a 3D open-cellular polymer structure constructed of interconnected hollow tubes, each with a wall 1,000 times thinner than a human hair, at the nanometer, micron and millimeter scales. In other words, the nickel-phosphorous material is only 0.01% solid, and is so light it can rest atop a dandelion fluff without disturbing it. 

According to NBCNews.com, researchers fabricated the material using a matrix of polymer lattices, and then depositing thin films of nickel-phosphorus. When the polymer is etched away, tiny metal tubes are left behind in the shape of the lattice.

Lorenzo Valdevit, Ph.D., a materials scientist at the university, said materials actually get stronger when the scale is reduced to the nanometer level. "Combine this with the possibility of tailoring the architecture of the microlattice, and you have a unique cellular material," he says, according to NBCNews.com. "You might argue that it's a 'structure' rather than a 'material,” he added.

IMPORTANCE OF LIGHTWEIGHT MATERIALS

Lightweight materials play an important role in reducing fuel consumption in the transportation sector. As a result, they also make a significant contribution to lowering emissions of greenhouse gases and other pollutants produced from burning fossil fuels, according to Andrew McWilliams, BCC Research analyst. 

“The transport sector accounts for by far the largest share of global liquid fuel consumption," he says. “An estimated 75% of vehicle energy consumption is related to factors associated with weight. Transportation’s share, (which includes aircraft, aerospace and motor vehicles), of global liquid fuels consumption is expected to increase to 61% by 2035.” Reducing the weight of a vehicle component by using lightweight materials has a multiplier effect on overall vehicle weight, and hence, will lessen fuel use.

The microlattice, originally developed for the Defense Advanced Research Projects Agency (DARPA), could be used for battery electrodes, catalyst supports, and acoustic, vibration or shock energy damping. According to DailyMail.com, HRL says the material could be used in planes as flooring, seat frame and wall composition. The firm also is working with NASA on future spacecraft designs.

"We are building on our breakthrough invention of ultralight metallic microlattices and will mature this technology to be applied in the next generation of space vehicles," says Tobias Schaedler, Ph.D., lead author of the study.

McWilliams says lightweight materials are projected to increase their share of total light vehicle materials content over the next five years under the combined impact of advances in materials technology, high fuel costs and more stringent government fuel economy standards.  

As a result of those factors, BCC Research reveals that lightweight materials will increase its share of the total materials content of autos and light trucks by 18% over the next five years. The total materials content of autos and light trucks produced globally should rise from 47.2% in 2015 to 66.5% by 2020.

Topics: Advanced Materials