Ultralight material
Ultralight materials are very light substances.[1] They include silica aerogels, carbon nanotube aerogels, metallic foams, polymeric foams, and metallic microlattices. The density of air is about 1.275 mg/cm3, which means that the air in the pores greatly lowers the density of the material.[2]
The lightest material ever made was invented in 2011. It is made out of a microscopic micro-lattice of hollow tubes – a criss-cross diagonal pattern with open spaces between the tubes. The researchers say the material is 100 times lighter than Styrofoam and is very strong.[3] The material is low density: it has a density of 0.9 milligrams per cubic centimetre. Silica aerogels, the world's lightest solid materials, are only as low as 1.0 mg per cubic cm. The metallic micro-lattices are 99.99% air and only 0.01% solid.[3] The metal used is nickel.[4]
- "The trick is to fabricate [make] a lattice of interconnected hollow tubes with a wall thickness of 100 nanometers, 1,000 times thinner than a human hair", said Tobias Schaedler.[4]
The material is not just light: it has some elastic properties. When it is squashed, the little tubes are also squashed, but when the pressure is removed, they rebound.[5] A sample squashed to half its height rebounds 98% when the pressure is lifted. That makes the material similar in some ways to elastomers: they are materials used to cushion against shock.[4]
References
- ↑ Less than 10 mg/cm3
- ↑ Schaedler T.A. et al. 2011 (2011). "Ultralight metallic microlattices". Science. 334 (6058): 962–965. doi:10.1126/science.1211649. PMID 22096194. S2CID 23893516.
- ↑ 3.0 3.1 World's 'lightest material' unveiled by US engineers. BBC Technology News: [1]
- ↑ 4.0 4.1 4.2 "Breakthrough material barely denser than air: CBS News Tech". CBS News. Archived from the original on 2011-11-18. Retrieved 2011-11-19.
- ↑ rebound = return to original shape