A team of engineers at the Massachusetts Institute of Technology has successfully designed a new 3D material with five percent the density of steel and ten times the strength. By compressing and fusing flakes of graphene, a two-dimensional form of carbon, the sponge-link configuration is one of the strongest and lightest known materials.

The new findings, reported in the journal Science Advances, show that the crucial aspect of the new 3D form is its unusual geometrical configuration, not the material itself. The discovery suggests that similar strong, lightweight materials could be made from a variety of materials by creating similar geometric features.

Using heat and pressure, the team compressed small flakes of graphene, producing a strong, stable structure resembling the form of some corals and microscopic creatures called diatoms. The shapes, which feature an enormous surface area in proportion to their volume, proved to be remarkably strong.

To test the strength and mechanical properties of the lightweight material, the MIT researchers created a variety of 3D-printed gyroid models.

The new configurations, made in the lab using a high-resolution, multimaterial 3D printer, were mechanically tested for their tensile and compressive properties. Their mechanical response under loading was simulated using the team’s theoretical models. The results from the experiments and simulations matched accurately.

Many other possible applications of the material could eventually be feasible, the researchers said, for uses that require a combination of extreme strength and light weight.

“You could either use the real graphene material or use the geometry we discovered with other materials, like polymers or metals,” said Markus Buehler, the head of MIT’s Department of Civil and Environmental Engineering (CEE). According to Buehler, the new design gains similar advantages of strength combined with advantages in cost, processing methods, or other material properties (such as transparency or electrical conductivity).

“You can replace the material itself with anything,” Buehler said. “The geometry is the dominant factor. It’s something that has the potential to transfer to many things.”


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