BINGHAMTON, NY — Ultra-fast travel is a key ingredient to most visions of the future.
Elon Musk is already working on concepts like the high-speed hyperloop train and city-to-city rocket travel, while NASA’s scramjet aircraft have been able to reach Mach 10 for well over a decade. As such projects move forward, new materials that are strong and heat resistant enough to handle that speed will be needed — materials with capabilities that go beyond carbon fiber, beyond even carbon nanotubes.
In the quest to test out candidates for that new material, researchers at Binghamton University are studying what are known as boron nitride nanotubes or BNNTs for short, alongside NASA scientists, of course.
“NASA currently owns one of the few facilities in the world able to produce quality BNNTs,” says associate professor of mechanical engineering Changhong Ke in a press release. “Typically, carbon nanotubes have been used in planes for their strength —they’re stronger than steel— and their ability to conduct heat. However, BNNTs are the wave of the future when it comes to air travel.”
Funded in part by the U.S. Air Force, the study tests the material’s ability to withstand the kind of heat generated in the atmosphere. With scientists and engineers turning their attention to aircraft that could travel at hypersonic speeds — between five and 10 times the speed of sound — the strength and heat-resistance of a machine is absolutely essential.
“We weren’t testing this material in a vacuum, like what you would experience in space. Materials can withstand much higher temperatures in space,” Ke says. “We wanted to see if BNNTs could hold up in the type of environment an average fighter jet or commercial plane would experience.”
Carbon nanotubes, which are currently one of the highest-tech materials in use in high-speed vehicles, can stay stable up to 400 degrees Celsius. This is pretty impressive, but the researchers discovered that BNNTs can do more than twice that.
“Our study found that BNNTs can withstand up to 900 degrees Celsius,” says Ke. “BNNTs are also able to handle high amounts of stress and are extremely lightweight.”
So how soon will this material be used on an actual airplane?
“Right now, BNNTs cost about $1,000 per gram. It would be impractical to use a product that expensive,” says Ke.
The researchers don’t expect things to stay that way. Carbon nanotubes were just as expensive a couple decades ago and now come in at about $10 to $20 a gram. Ke says BNNTs will likely follow suit. And since fighter jets don’t exactly have small budgets, the researchers expect that they will be some of the first aircraft to make use of the material.
But, research has shown that time spent traveling can take a severe psychological toll on people who have to do it often. Accordingly, high-flying business people are likely to be willing to pay a premium to get from A to B faster. And as billionaire innovators Elon Musk and Richard Branson announced yesterday that they are teaming up on the hyperloop project — now named Virgin Hyperloop One — it is increasingly clear that the private sector will also be seeking new materials to get things moving faster closer to earth.
Out in space, past even such exotic uses as fighter jets, NASA is looking at even greater obstacles that BNNTs can help them overcome. One example being the mission to Mars. According to Sheila Thibeault, a materials researcher at NASA, BNNTs could be an ideal material for the spacecraft and suits used in the voyage to another planet.
“This material is really strong—even at high heat—meaning that it’s great for structure,” says Thibeault in an article on the space agency’s website, which explains a version of BNNT augmented with hydrogen could shield against dangerous radiation.
For the everyday person though, it’s hard to say exactly where they will first encounter this material of the future. For his part, Ke says he can see the technology making its way to commercial flights in years to come.
The full study on BNNTs was published this week in a paper in the journal Scientific Reports.