When it comes to metamaterials, it’s the magical substance known as “aerogel” that gets all the coverage. But what if we could construct super-substances using materials we’re more familiar with, including regular metals and plastic? Researchers at MIT and the Lawrence Livermore National Laboratory in the US think they might have something.
The clip above explains the process engineers are experimenting with to manufacture the aforementioned materials, which exhibit incredible strength while also being remarkably light. 3D printing is at the heart of the development, allowing the construction of “microlatticies with nanoscale features” using “projection microstereolithography”. The principle idea is that the toughness you’d usually get from increased density is substituted with the precise arrangement of structures within the material to optimise its stiffness.
According to MIT engineering design professor Nicholas Fang, the initial results were a “pleasant surprise”:
The geometric basis for such microstructures was determined more than a decade ago, Fang says, but it took years to transfer that mathematical understanding “to something we can print” … the result was “a pleasant surprise to us,” he adds, performing even better than anticipated.
“We found that for a material as light and sparse as aerogel [a kind of glass foam], we see a mechanical stiffness that’s comparable to that of solid rubber, and 400 times stronger than a counterpart of similar density. Such samples can easily withstand a load of more than 160,000 times their own weight.”
The MIT press release goes on to mention that the technique has been applied successfully to “metal, ceramic and polymer”, so there’s no requirement for special materials. Fang says there’s even the potential for use in batteries, making portable devices even lighter than they are today.