Scientists create world's lightest material 1,000 times thin
usinfo | 2012-12-29 16:34
Scientists claim to have created  the world’s lightest solid material, a metal which can sit atop a dandelion without even crushing its seeds.
 
The substance is made of tiny hollow metallic tubes – the walls of which are 1,000 times thinner than those of a human hair – arranged into a criss-crossing diagonal pattern with small open spaces between them.
 
The researchers say the material, which consists of 99.99 per cent air, is 100 times lighter than Styrofoam and has ‘extraordinarily high energy absorption’ properties.
 
Lightweight: The revolutionary new material is made out of hollow tubes with a wall thickness 1000 times thinner than a human hair
 
Its potential future uses include thermal insulation, battery electrodes, and products to dampen sounds or vibration, or absorb shock.
 
The research, published in the latest edition of the journal Science, was carried out at the University of California, and the Irvine and HRL laboratories.
 
The engineers say the material’s strength derives from the ordered nature of its lattice design.
 
William Carter, of HRL, said: ‘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.’
 
The lattice design of the new material has been compared to the construction of the Eiffel tower, albeit on a micro scale
 
Lead author Dr Tobias Schaedler, said: 'The trick is to fabricate a lattice of interconnected hollow tubes with a wall thickness 1,000 times thinner than a human hair.
 
'The resulting material has a density of 0.9 milligrams per cubic centimetre'.
 
By comparison the density of silica aerogels - the world's lightest solid materials - is only as low as 1.0mg per cubic cm.
 
The engineers say the material's strength derives from the ordered nature of its lattice design.
 
Other ultralight substances, including aerogels and metallic foams, have random cellular structures meaning they are less stiff, strong, energy absorptive or conductive than the bulk of the raw materials that they are made out of.
 
To study the strength of the metallic micro-lattices the team compressed them until they were half as thick.
 
After removing the load the substance recovered 98 per cent of its original height and resumed its original shape.
 
The first time the stress test was carried out and repeated the material became less stiff and strong, but the team says that further compressions made very little difference.
 
'Materials actually get stronger as the dimensions are reduced to the nanoscale,' said team member Lorenzo Valdevit.
 
'Combine this with the possibility of tailoring the architecture of the micro-lattice and you have a unique cellular material.'
 
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