It might be weird looking, but it gets the job done.

Researchers at MIT have 3-D printed one of the strongest lightweight materials ever. It's 10 times stronger than steel--yet only 1/20th its density.

The researchers published their findings in a new report in the peer-reviewed journal Science Advances. Their material has a strange shape to it, which is exactly what makes it so strong. It was made by taking flakes of graphene--a strong, lightweight, 2-dimensional form of carbon--compressing them, and fusing them together using 3-D printing.

Since graphene is naturally strong in its one-atom-thick state, the scientists decided to reproduce its shape in three dimensions. Other teams in the past have produced 3-D versions of graphene, but the results haven't been as strong as predicted. The MIT team overcame that hurdle by studying the 2-D structure down to its individual atoms, then using mathematical equations to map out the ideal shape of the 3-D version.

Using 3-D printing, the team tried many different designs before settling on the strongest shape. The result is a product that looks like a piece of coral or a sponge, but can actually withstand 10 times more pressure than steel. (Picture a sheet of paper rolled up into a cylinder with textbooks stacked on top of it--the physics behind it are similar.) As you apply excessive pressure, the material breaks down piece by piece instead of failing all at once.

The findings could have wide application in manufacturing. Airplanes, vehicles, buildings, or any structure meant to be strong and lightweight could benefit--and even if entire products aren't made using it, individual parts could be.

And while the 3-D graphene is exceptionally strong, the findings related to the shape might be even more important. "You can replace the material itself with anything," Markus Buehler, head of MIT's Department of Civil and Environmental Engineering, told MIT News. "The geometry is the dominant factor. It's something that has the potential to transfer to many things."

Because of the complexity of the graphene's shape, it likely couldn't have been created using traditional manufacturing processes. Three-dimensional printing, or additive manufacturing, allows for shapes to be drawn on computers and then printed as one uniform piece. The method has already begun to impact the $400 billion commercial aircraft manufacturing industry: GE is producing 3-D printed fuel nozzles that are 25 percent lighter than traditional ones, and Airbus has its own printed components almost ready for use.

Check out MIT's video below for a demonstration of the 3-D graphene material in action.

 

Published on: Jan 10, 2017