A new method of producing extremely lightweight materials with unlikely properties could herald the advent of architectural engineering on the micro-scale.
Many ultra-low density materials have already been produced based on carbon nanotubes, metallic foams and the like. But these have random structures, notes materials scientist Tobias Schaedler of HRL Laboratories in Malibu.
His team’s new material, described this week in Science, consists of a regular arrangement of metallic tubes intersecting at nodes and is made by plating nickel-phosphorous onto a carefully produced polymer micro-lattice.
Schaedler compares this approach to macro-scale objects such as the Eiffel Tower, which has an impressive size and rigidity despite its relative lack of mass, due to its careful and non-random design.
“The long term vision is to bring architecture that’s responsible for modern buildings like the Eiffel Tower to the materials level,” he says.
His team made various versions of the metal micro-lattice described in their new paper, one of which came in at an amazingly low density of 0.9 milligrams per cubic centimetre (measured, as is convention, excluding the air in the pores).
Unlike the rather brittle properties of nickel-phosphorous in bulk, the new material is surprisingly springy and can completely recover from being compressed, as shown in the video below. It also has very good energy absorption properties.
Schaedler says versions of it could eventually find use in everything from insulation materials to the aerospace industry. Perhaps more ambitiously, he hopes this could usher in a new approach to materials, where careful control of the structure can produce materials with properties wildly different from the original elements.
“There are only so many elements in the periodic table. If we introduce structure architecture we can make new materials with new properties,” says Schaedler.
Image top: HRL Laboratories LLC / picture by Dan Little
Video: HRL Laboratories LLC, narration by Science press team