Sunday, November 20, 2011

World's ‘lightest material' developed

Scientists have developed what they claim is the world's lightest material — a metal with a density of 0.9 mg/cc.
A team from the University of California, the California Institute of Technology and the HRL Laboratories says that the new material redefines the limits of lightweight materials because of its unique “micro-lattice” cellular architecture.
The scientists were able to make a material that consists of 99.99 per cent air by designing the 0.01 per cent solid at the nanometre, micron and millimetre scales, the latest issue ofSciencereported.
“The trick is to fabricate a lattice of interconnected hollow tubes with a wall thickness 1,000 times thinner than a human hair,” said lead scientist Tobias Schaedler of HRL.
The material's architecture allows unprecedented mechanical behaviour for a metal, including complete recovery from compression exceeding 50 per cent strain and high energy absorption, say the scientists.
“Materials actually get stronger as the dimensions are reduced to the nano-scale. Combine this with the possibility of tailoring the architecture of the micro-lattice and you have a unique cellular material,” team member Lorenzo Valdevit said.
Developed for the Defence Advanced Research Projects Agency, the novel material could be used for battery electrodes and acoustic, vibration or shock energy absorption, say the scientists.
William Carter, manager of the architected materials group at HRL, compared the new material to larger, more familiar edifices: “Modern buildings, exemplified by the Eiffel Tower or the Golden Gate Bridge, are incredibly light and weight-efficient by virtue of their architecture. We are revolutionising lightweight materials by bringing this concept to the nano and micro scales.”