Glass-coated DNA is 4x stronger but 5x less dense than steel

Glass a few hundred atoms thick

Because it’s very difficult to create a large piece of glass without flaws, the researchers began with very small flawless pieces. As long as the glass is less than a micrometer thick, it’s almost always flawless as well as strong and lightweight.

The team then developed a structure of self-assembling DNA and coated it with a very thin layer of glass-like material only a few hundred atoms thick. The DNA skeleton reinforced the thin, flawless coating of glass, making the material very strong, while the voids comprising most of the material’s volume made it lightweight. 

The end result was glass nanolattice structures that are four times higher in strength but five times lower in density than steel. 

“The ability to create designed 3D framework nanomaterials using DNA and mineralize them opens enormous opportunities for engineering mechanical properties. But much research work is still needed before we can employ it as a technology,” said Oleg Gang, nanomaterials scientist at Columbia University and Brookhaven’s Center for Functional Nanomaterials, who was part of the new work.

The team now plans to experiment with different DNA to explore different results and perhaps conceive of an even tougher material.

“I am a big fan of Iron Man movies, and I have always wondered how to create a better armor for Iron Man. It must be very light for him to fly faster. It must be very strong to protect him from enemies’ attacks. Our new material is five times lighter but four times stronger than steel. So, our glass nanolattices would be much better than any other structural materials to create an improved armor for Iron Man,” said Lee in the statement.

For now, future materials based on this approach show great promise as energy-saving materials for vehicles and other devices that prioritize strength. 

The study is published in Cell Reports Physical Science.

Study abstract:

Continuous nanolattices are an emerging class of mechanical metamaterials that are highly attractive due to their superior strength-to-weight ratios, which originate from their spatial architectures and nanoscale-sized elements possessing near-theoretical strength. Rational design of frameworks remains challenging below 50 nm because of limited methods to arrange small elements into complex architectures. Here, we fabricate silica frameworks with ∼4- to 20-nm-thick elements using self-assembly and silica templating of DNA origami nanolattices and perform in situ micro-compression testing to examine the mechanical properties. We observe strong effects of lattice dimensions on yield strength (σy��) and failure mode. Silica nanolattices are found to exhibit yield strengths higher than those of any known engineering materials with similar mass density. The robust coordination of the nanothin and strong silica elements leads to the combination of lightweight and high-strength framework materials offering an effective strategy for the fabrication of nanoarchitected materials with superior mechanical properties.