Researchers from UConn, Columbia University, and Brookhaven National Lab have created a material lighter and stronger than steel from two unlikely components:
Lee and colleagues report that by building a structure out of DNA and then coating it with glass, they have created a very strong material with very low density. Glass might seem a surprising choice, as it shatters easily. However, glass usually shatters because of a flaw – such as a crack, scratch, or missing atoms – in its structure. A flawless cubic centimeter of glass can withstand 10 tons of pressure, more than three times the pressure that imploded the Oceangate Titan submersible near the Titanic last month.
It’s very difficult to create a large piece of glass without flaws. But the researchers knew how to make very small flawless pieces. As long as the glass is less than a micrometer thick, it’s almost always flawless. And since the density of glass is much lower than metals and ceramics, any structures made of flawless nano-sized glass should be strong and lightweight.
The team created a structure of self-assembling DNA. Almost like Magnatiles, pieces of DNA of specific lengths and chemistry snapped themselves together into a skeleton of the material. Imagine the frame of a house or building, but made of DNA.
Oleg Gang and Aaron Mickelson, nanomaterials scientists at Columbia University and Brookhaven’s Center for Functional Nanomaterials, then coated the DNA with a very thin layer of glass-like material only a few hundred atoms thick. The glass only just coated the strands of DNA, leaving a large part of the material volume as empty space, much like the rooms within a house or building.
The DNA skeleton reinforced the thin, flawless coating of glass making the material very strong, and the voids comprising most of the material’s volume made it lightweight. As a result, glass nanolattice structures are four times higher in strength but five times lower in density than steel. This unusual combination of lightweight and high strength has never been achieved before.
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The team is currently working with the same DNA structure but substituting even stronger carbide ceramics for glass. They have plans to experiment with different DNA structures to see which makes the material strongest.
Transparent aluminum??!!
What happens when it gets wet?
Sounds like a material with a particularly nasty fatigue cycle: perfect for the next Oceangate wannabe.
“…it’s almost always flawless.”
Almost. The structure is almost finishing collapsing. Send more grant money.
“What happens when it gets wet?”
What happens when windows get wet?
Or sand? Or your wine glass or labware?
Nothing. Awesome are the silicates.
Anyway, unlikely that water could permeate far into something with that small a structure. Even as big as 5 microns, the pores on a fine fritted glass filter barely let water through without additional pressure. Related to why water slowly gets trapped in (alumino)silicate molecular sieves.
Also, DNA is made to work in cells which are always wet.
Also, nucleic acids aren’t too different from amino acids, and of course nature makes tons of light and tough and materials with peptides, sometimes reinforced or as a scaffolding for hard inorganic martial. Nature got to this trick first. Like calcium carbonates in shells and bones or hydroxyapatite in dentin in teeth and scales. Not only merely resistant, many creatures obviously live in the water, life came from the water.
Even if I’m wrong about all that, they could just coat the surface of bulk material in polymer or something else waterproof.
”A flawless cubic centimeter of glass can withstand 10 tons of pressure, more than three times the pressure that imploded the Oceangate Titan submersible near the Titanic last month.”
Makes it sound weak. A cubic centimeter of steel would be in the 50 ton range.
Depends on the geometry.
There’s some PR sleight-of-hand in play here: They’re talking about compressive yield strength — not tensile strength — so “4x stronger than steel” isn’t saying very much, as steel isn’t a very strong material in compression.
In general, ceramics and glasses (both traditional silica glasses and new metallic glasses) all have very high compressive strengths, but very poor tensile strengths. Martensitic steel can combine decent compressive strength with outstanding tensile strength — and, to simplify things a bit, it’s tensile strength which basically corresponds to “damage tolerance” and “resistance to brittle failure.”
They’re also looking at an extremely small sample size that might not scale. Frankly, I’m unaware of any nano-lattice material in use towards any application.
What they’ve done is taken an existing silica glass — a material traditionally very strong in compression — and they’ve structured it so that their sample is a lattice of very narrow struts. This both reduced the defect rate in the glass and enabled them to remove some material, lowering density and improving specific strength.
Ultimately, it’s cool as a scientific curiosity and a work of engineering ingenuity, but it has no near-term practical applications, and it’s not stronger in compression than existing ceramic materials. (e.g. silicon carbide, which has a pretty much identical compressive strength.)
Does this mean they can make phone screens that won’t crack?
“Does this mean they can make phone screens that won’t crack?”
Afraid not. The material in question is still brittle and would surely have undesirable optical properties. Besides, the discoverers have yet to make a sample large enough to be seen without a microscope (the largest sample they produced was 8µm in diameter, with most clustering around 3µm), and it remains unclear whether nano-lattice materials can be made in bulk at all, as a practical matter.