When Iron Man needs a new suit, he might use materials created by scientists at Columbia University — a glass DNA nanostructure five times lighter and four times stronger than steel.
The search for materials that balance strength and lightness is an ongoing challenge. Various types of steel are extremely strong, but heavy. Aluminum is lighter, but not as strong. Carbon composites are strong and light, but difficult to manufacture.
The core idea of their approach lies in exploiting the potential strength of glass. Yes, that same glass that can shatter with a tap. The reason why glass breaks easily is largely due to imperfections in its structure, like cracks or missing lattice atoms. Scientists made a metallic glass in 2011 that was tougher than steel but did not shatter, by adding silver and palladium. The current project uses DNA (deoxyribonucleic acid), the same stuff that encodes the building and operating instructions .
Glass is usually made from silica, a molecule of silicon and oxygen. It can form into a unique structure that is like both a solid and liquid, called a glass. The research team from the University of Connecticut, Columbia University, and Brookhaven National Lab, says flawless glass is extremely strong. Iron, for example, can handle 7 tons of pressure per square centimeter. A flawless centimeter of glass can withstand 10 tons of pressure.
To shape flawless glass particles into a solid 3D framework, the researchers turned to DNA, which they use as a scaffolding. Like the frame of a building. Except this building is self-assembling. And the glass is a coating on the framework. A sheet of glass a few hundred atoms thick is strong and light, able to fit on the DNA nanostructure.
The images at the top (A) show how the skeleton of the structure is assembled with DNA, then coated with glass. (B) shows a transmission electron microscope image of the nanomaterial, and (C) shows a scanning electron microscope image, with the right-hand panels zooming in to features at nanometer (10e-9) scales. “origami” is a term borrowed from Japanese art, and refers to folding the DNA. Credit: University of Connecticut
In lab tests, the scientists found their glass-DNA material could take compression up to 5 GigaPascals (GPa). They say this is four times stronger than ordinary steel but with one-fifth of the density. “For the given density, our material is the strongest known,” said Seok-Woo Lee, co-corresponding author of the study. “But much research work is still needed before we can employ it as a technology.”
Next, the researchers plan to make even stronger materials using DNA structure. For instance, substituting carbide ceramics for glass could produce materials with even higher strength-to-weight ratios. They will also experiment with different DNA structures to see which combination of framework and coating makes the material strongest.
Strong, lightweight materials allow for lightweight body armor, better medical devices, and make safer, faster cars and airplanes. The easiest way to extend the range of an electric vehicle, for example, is not a bigger battery but making the vehicle itself lighter and stronger.
As for superheroes, Lee said: “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.” His nanoglass is actually in the ballpark of how strong and light Iron Man’s armor would have to be (though we’re still missing the technology for the force fields, repulsor rays, et cetera — be patient, research is being done on those too).
For more on nanomaterials, here’s our article on real nanobots.
The findings appeared in the journal Cell Reports Physical Science.
David Raiklen wrote, directed and scored his first film at age 9. He began studying keyboard and composing at age 5. He attended, then taught at UCLA, USC and CalArts. Among his teachers are John Williams and Mel Powel.
He has worked for Fox, Disney and Sprint. David has received numerous awards for his work, including the 2004 American Music Center Award. Dr. Raiklen has composed music and sound design for theater (Death and the Maiden), dance (Russian Ballet), television (Sing Me a Story), cell phone (Spacey Movie), museums (Museum of Tolerance), concert (Violin Sonata ), and film (Appalachian Trail).
His compositions have been performed at the Hollywood Bowl and the first Disney Hall. David Raiken is also host of a successful radio program, Classical Fan Club.