Chris Boyd

Nov 23rd 2018

Scientists Engineer Materials from the Atom Up


Consider it a new age in manufacturing and engineering.

Unlike in days past, when workers shaped simple tools out of a given material, be it stone, wood or steel, today marks a revolution in manufacturing. Engineers can now tweak complex materials at the microscopic level so they perform to their specifications. “It’s kind of turning the problem on its head. We can tailor-make any material to solve the problem,” said Northrop Grumman’s Luke Sweatlock, director of research for Materials and Devices, Basic Research. “You can apply these principles on the atomic and molecular scales, and you can create things that have really surprising and unique properties.”

For instance, imagine a carefully shaped piece of glass, such as a lens. Due to the laws of physics, the light entering that lens always bends in a way that is expected, and atoms polarize the light in a certain way. However, scientists like Sweatlock and his team members can make a lens that is shaped in another manner, at the smallest level imaginable, so that it bends light in a different way.

“Now you’re kind of back to the drawing board,” said Sweatlock, who has spent the last decade working at Northrop Grumman. “What can you do with this material that’s never been available before?”

In the realms of aerospace and consumer products, engineered materials can have powerful applications when it comes to thermal properties. If a device consumes power, be it a spacecraft engine or a cell phone battery, it generates heat. Often such heat limits the device’s performance. On Earth, that may not be a huge deal, but in space, there is no convection, and “that’s a huge problem,” Sweatlock explains. “There is still a lot of room for engineering improvement.”

That’s where Jesse Tice comes in. Tice, principal scientist and Nanomaterials Group lead, is an eight-year veteran of Northrop Grumman who works in the nanometer regime — for comparison, a human hair measures 10 to 100 micrometers; Tice and his teammates work on a scale 10,000 to 100,000 times smaller than that. “One of my first projects was on thermal transport,” Tice said.

In the laboratory, Tice uses vertically aligned nanowire arrays to improve conductivity and break down thermal bottlenecks between microelectronic systems. These systems are a series of tiny integrated circuits that enable communications between satellites and Earth-based stations, among other applications. “[Copper nanowires] are 10 times more efficient than the current practice,” he said. “This is for the next generation of microelectronics, which are extremely high power.”

Tice and his teammates don’t stop with thermal innovations. They also delve into additive manufacturing, or 3-D printing. Instead of printing standard color inks like you might on a device at home, they print gold and other phase-changing inks that end up as radiofrequency filters, wave guides, antennas and the like. “We can manufacture them extremely quickly,” Tice said. “We’re able to get improved or enhanced performance over traditional flat components with our fully 3-D printed approach.”

Finally, he is looking into thin materials such as the semi-metal graphene, which is just one atom thick. Team members can take these materials and stack one on top of the other to create new functionalities, as well as image cross-sections to view one atom at a time.

By stacking graphene on a new material known as gallium oxide, Tice said, the team demonstrated a new record high breakdown voltage for gallium oxide. This fundamental advancement could help develop new power converters for grid-scale electric power or advanced components that replace gallium nitride in high-performance microelectronic applications.

The report, appearing in January 2018 in Applied Physics Letters, earned the team kudos in the scientific community. “We’ve been making some really good progress,” Tice said.

All this may sound more like science fiction than science fact, but it’s happening at Northrop Grumman in places like Redondo Beach and Manhattan Beach, Calif., and in Bethpage, N.Y. Indeed, thanks to the efforts of the company’s scientists, devices like the tricorder in TV’s “Star Trek” could become reality. The tricorder was used to scout unfamiliar territory like alien worlds, examine living beings and record and analyze data. A trio of doctors last year introduced a real-life tricorder for medical applications.

“How do we develop new design principles that allow us to break rules in a constructive way?” Sweatlock asks. “In the future, we’re going to leverage the quantum realm. The next step is tinkering with the laws of quantum mechanics.”

Historically, aerospace composites, alloys and coatings have brought success to companies like Northrop Grumman. With these new breakthroughs, the sky is definitely the limit.

Sweatlock sees collaboration among his peers in the labs as a key to that success. “What really makes it special is the interdisciplinary crosstalk that can happen in the labs,” he said. “We can walk down the hall here and say, ‘Here is what we discovered,’ and our counterparts can say, ‘Here are the challenges.’ That’s what makes it all come together.”

“We see and work with colleagues who are at the leading edge,” Tice said. “Eventually that leads to world-discriminating technologies.”

Concluded Sweatlock, “There’s just no limit to what you can do by engineering materials from the ground up.”