By Dr. Cameron Chai
Scientists at the University of California-Irvine, the California Institute of Technology and HRL Laboratories have synthesized the world’s lightest metal having a density of 0.9 mg/cc, a value 100 folds lesser than the density of Styrofoam.
New metal - which is 99.9 percent air - is so light that it can sit atop dandelion fluff without damaging it. (Credit-New metal - which is 99.9 percent air - is so light that it can sit atop dandelion fluff without damaging it.)
The researchers have published their results in the Science journal. The new material’s low density is caused by its special ‘micro-lattice’ cellular structure, which contains 99.99% of air and 0.01% solid at the millimeter, micron and nanometer scales.
HRL’s Dr. Tobias Schaedler, who is also the lead author of the study, stated that the technique is to produce an interlinked hollow tube lattice having a wall thickness nearly 1000 times lesser than human hair width. The innovative material’s structure makes a metal to have superior mechanical properties such as unprecedented energy absorption and total compression recovery higher than 50% strain. The unique material is designed for the Defense Advanced Research Projects Agency and finds applications in battery electrodes and shock, acoustic and vibration energy absorption.
Lorenzo Valdevit, a mechanical and aerospace engineer at the University of California-Irvine and the principal investigator of the study, stated that the material becomes stronger when its size decreases to the nanoscale. Based on this fact, the research team customized the micro-lattice structure to fabricate the novel cellular material, he said.
William Carter, who serves as HRL’s Manager of the Architected Materials Group, commented that modern structures, including the Golden Gate Bridge and the Eiffel Tower, are lightweight and weight-efficient considering their architecture. The research team used this idea to the micro- and nanoscales to develop the innovative lightweight materials, he said.