Scientist develop ultra-tough, ultra-light 3D printed meta-material

By Design Engineering Staff June 25, 2014

CAD/CAM/CAE Materials Metal Fabrication

MIT, Lawrence Livermore-created substance is as light as aerogel but 10,000x stiffer.

Engineering researchers at Lawrence Livermore National Laboratory and MIT announced they’ve developed a material that has the same density and weight as aerogel — one of the lightest materials on earth — but with 10,000 times the stiffness. Created using a micro-additive manufacturing process, the new meta-material can withstand a load of up to 160,000 times its own weight, said lead LLNL researcher Xiaoyu “Rayne” Zheng.

“The key to this ultrahigh stiffness is that all the micro-structural elements in this material are designed to be over constrained and do not bend under applied load,” he said.

In addition, the researchers found that the substance’s high stiffness is due mainly to its micro-structure and not the mechanical properties of the base material as the process works as well with polymers, metals and ceramics.

The process — called projection micro-stereolithography – involves the use of digital micro-mirror or DLP chip containing an array of tiny mirrors. The high-density mirror array allowed the researchers to produce complex 3D microlattices, one layer at a time, from a photosensitive polymer build material.

The lattices were then coated with a thin metal or ceramic film and the internal polymer melted, leaving a hollow-tube strut. The result is one of the lightest materials in the world but with four orders of magnitude higher stiffness, the researchers say.

“Now we can print a stiff and resilient material using a desktop machine,” said MIT professor and key collaborator Nicholas Fang. “This allows us to rapidly make many sample pieces and see how they behave mechanically.”

According to the researchers, the material and process could have revolutionary implications for the aerospace and automotive industries where weight savings translate directly to complementary increases in fuel economy.

The Department of Defense’s Defense Advanced Research Projects Agency (DARPA) and Lawrence Livermore’s Laboratory Directed Research and Development (LDRD) program funded the team’s research.
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