Vincent Crespi Lab/Penn State University Diamond nanothreads are only a few atoms across, more than 20,000 times thinner than a human hair. They're also stronger and stiffer than any carbon nanotube or polymer to date, which could make them an ideal option for a space elevator tether.
A space elevator is essentially a cable anchored to the Earth's equator and attached to a counterweight somewhere way above Earth's atmosphere — much higher than satellites in orbit. Having one would allow us to send cargo into space for a fraction of the cost of using rockets and allow us to harvest vast amounts of solar energy by placing solar collectors well above the Earth's atmosphere, where the sun never stops shining.
Finding a material strong enough to serve as a tether is one of the most daunting technical challenges standing in the way.
Earlier this year, however, researchers may have accidentally discovered the best candidate yet for building a space elevator. A set of diamond nanothreads created under immense pressures in a lab might rival or exceed the strength of carbon nanotubes , which are 100 times stronger than steel.
A little bit of luck
J ohn Badding of Penn State University and his team discovered that liquid benzene, when subjected to extreme pressure (around 200,000 times the pressure at the surface of the Earth) and then slowly relieved of that pressure, forms extremely thin, tight rings of carbon that are structurally identical to diamonds.
In other words, if you could unravel a diamond like you can a piece of fabric, you'd get these far-out threads. The result is a chain, thousands of times thinner than a human hair, that has the potential to be the strongest, stiffest material ever discovered.
The discovery was something of an accident, but far from a hapless one. The team used a large, high-pressure device called the Paris-Edinburgh device at Tennessee's Oak Ridge National Laboratory to compress a 6-millimeter wide quantity of liquid benzene — a huge amount compared with previous experiments. The volume of liquid benzene, coupled with the size of the device, forced them to relieve the pressure more slowly than they would have otherwise.
"It's been known for a long time that if you put benzene under pressure, it’d make a type of polymer," Badding told Business Insider. "An Italian team did a similar experiment and found it was amorphous, disordered, with no pattern to the way material’s held together, kind of like glass. We were trying to make the same material everyone else had made, but in larger quantities."