Now the world's lightest material has been developed !!!! So lets see how the engineers consider it the lightest!
Researchers in the US have broken the world record for the lightest structural material. The metal-based microlattice structures are significantly less dense than the rarest aerogels and other ultralight foams, while exhibiting high strength and an unexpectedly high ability to absorb energy and recover shape after compression. The materials could find use in a range of applications, from aircraft structural components to acoustic damping and shock absorption.
The 0.01 percent of the material that isn't air consists of a micro-lattice of interconnected hollow nickel-phosphorous tubes with a wall thickness of 100 nanometers - or 1,000 times thinner than a human hair. These tubes are angled to connect at nodes to form repeating, three-dimensional asterisk-like cells.The new material draws parallels with large structures, such as the Eiffel Tower, which is incredibly light and weight-efficient thanks to its hierarchical lattice design. As an illustration of just how efficient such a design is, if the 7,300 tonnes of metal used in the Eiffel Tower were melted down it would fill just six centimeters (2.4 in) of the structure's 125 m2 (1,345 square ft) base.The new materials super lightness is due to the way it has been constructed using interconnecting hollow nickel-phosphorous tubes which create a micro-lattice. The nickel-phosphorous tubes have a wall thickness of 100 nanometers, which is the equivalent of 1,000 times thinner than a human hair.
To create the structure, a polymer template is first produced by placing a mask patterned with circular holes over a reservoir of a photosensitive thiol-ene monomer. UV light is shone on the mask and where the light meets the monomer it polymerises it. 'As the light begins to polymerise the liquid monomer, the change in refractive index between the polymer and monomer begins to tunnel the light, just as in a fibre optic,' says Schaedler. 'This leads to the formation of a self-propagating photopolymer waveguide, or fibre, within the monomer reservoir. We form these waveguides in multiple directions and intersect them together to create an interconnected network. Then we clean out the uncured liquid monomer with a solvent, and the result is a micro-lattice structure, where the self-propagating waveguides are the individual structural lattice members.
This lattice template is then dipped in a catalyst solution before being transferred to a nickel-phosphorus solution. The nickel-phosphorus alloy is then deposited catalytically on the surface of the polymer struts to a thickness of around 100nm. Once coated, the polymer is etched away with sodium hydroxide, leaving an identical lattice geometry of hollow nickel-phosphorus tubes.In addition to its ultra-low density, the researchers say the new material's micro-lattice architecture gives it extraordinarily high energy absorption with the ability to completely recover from compression exceeding 50 percent strain. This is due to the fact that the extremely small wall thickness-to-diameter ratio of the material makes the individual tubes flexible.
Its impressive properties could see its uses in battery electrodes, catalyst supports, and acoustic, vibration or shock energy damping.So get the lightest material as soon as possible!
[via:rsc news]
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