New 'Diamond nanothreads' may make space elevator a reality
Scientists produce ultra-thin threads of carbon atoms they say should be stronger and stiffer than any existing man-made material. Space elevators, here we come.
A team of scientists have crafted a thread of carbon atoms 20,000 times smaller than a strand of human hair, and it may prove to be the strongest man-made material in the universe.
Called a "diamond nanothread," the ultra-thin material has a never-before-seen structure resembling the hexagonal rings of bonded carbon atoms that make up diamonds, the hardest known natural mineral on Earth. That makes these nanothreads potentially stronger and more resilient than the most advanced carbon nanotubes, which are similar super-durable and super-light structures composed of rolled up, one atom-thick sheets of carbon called graphene.
"Because this thread is diamond at heart, we expect that it will prove to be extraordinarily stiff, extraordinarily strong, and extraordinarily useful," John Badding, a chemistry professor at Penn State University who led the project, said in a statement. The work was published on September 21 in the journal Nature Materials.
The creation of a diamond-like nanomaterial is a first, marking a breakthrough after a century of unsuccessful attempts to compress carbon-based molecules into a structure with such strength. The team produced it by using a pressure device at Oak Ridge National Laboratory to compress an especially large 6-millimeter wide pool of benzene, a molecule composed of carbon and hydrogen. The benezene molecules first stacked, then bent and broke apart, only to form again when the team released the pressure in an entirely different fashion with a diamond configuration and a bonding structure that formed thin nanothreads.
Graphene and carbon nanotubes, which are both based on carbon atoms but differ in structure, are ushering in stunning advancements in the fields of nanotechnology and materials science. Isolated from graphite just 10 years ago, graphene offers the promise of revolutionizing electronics, energy storage and even medicine because of its incredibly low weight, its strength and its remarkable conductivity. Some of these applications include using graphene and carbon nanotubes to create next-generation touchscreens, solar cells, batteries and nanocomposities used in tissue engineering.
This new discovery of diamond nanothreads, if they prove to be stronger than existing materials, could accelerate current and future uses. That includes more fuel-efficient electric vehicles and even a durable cable that could send humans to space without the need of rockets.
"One of our wildest dreams for the nanomaterials we are developing is that they could be used to make the super-strong, lightweight cables that would make possible the construction of a 'space elevator' which so far has existed only as a science-fiction idea," Badding said.
Space elevators, which could become a source of solar energy and an avenue for cheap space exploration and tourism, would essentially wire a carbon nanotube-based cable 60,000 miles above Earth and use magnetic linear motors, the same that power maglev trains today, to send pods to space. A construction company in Japan, Obayashi Corporation, thinks advancements in nanotechnology will let it build and commercialize such a structure by 2050.
"The tensile strength is almost a hundred times stronger than steel cable so it's possible," Obayashi research and development manager Yoji Ishikawa told the Australian Broadcasting Corporation last month. "Right now we can't make the cable long enough. We can only make 3-centimeter-long nanotubes but we need much more... we think by 2030 we'll be able to do it."