Almost Bulletproof Sheet of Gold Is Only 50 Atoms Thick

Scientists managed to create an ultrastrong material that has many of the characteristics of the plexiglas, used to make bulletproof glass. The strange thing about this material is the fact that it's made of a 50-atom-thick layer of gold particles.

Seen under a microscope, the new material, developed by scientists at the University of Chicago and Argonne National Laboratory looks like a transparent sheet of closely packed gold nanoparticles separated by organic spacers, placed atop a silicon chip. It consists of gold particles separated by organic "bumpers" to keep them from coming into direct contact.

"It's an amazing little marvel," said Heinrich Jaeger, Professor in Physics at the University of Chicago. "This is not a very fragile layer, but rather a robust, resilient membrane." Some of the properties of this sheet are remarkable, like the fact that it maintains its structural integrity at relatively high temperatures, even when poked with ultrafine tips of metal.

"When we first realized that they can be suspended freely in air, it truly surprised all of us," said Xiao-Min Lin, a physicist at Argonne's Center for Nanoscale Materials. There are many potential applications of this incredibly thin, yet strong compound, like in precision technological processes where it could be used as a highly sensitive pressure sensor.

"If we use different types of nanoparticles to make the same kind of suspended membrane, we can even imagine using these devices as chemical filters to promote catalytic reactions on a very small length scale," Lin said.

Objects just a few nanometers wide could be produced using this new find as a building block, since it could be assembled with high precision on the nanoscale. "This is the ultimate limit of such a solid. It's just one layer," Jaeger said. "What is interesting is that already one layer is so resilient and has these interesting properties."