The problem of scale is unavoidable when talking about applying materials made in a laboratory into an industrial process. It’s one thing to make small transistors with submicron features, but what if you want to coat the entire surface of a jetliner with a conductive nanomaterial?
That’s the kind of problem Namiko Yamamoto is trying to solve.
“I’m from the Aerospace Engineering Department, and what I want to do is apply nano- and micro-engineered materials to airplanes, satellites, or other large structures,” says the assistant professor.
Engineering materials with high quality and functionality at the scale of a microchip or in a thin film is something materials researchers have the expertise to do well, but scaling those processes up to meter and multi-meter lengths is where these laboratory materials run into problems.
The unique properties that occur at the small scale can disappear at larger scale, or the performance of the material degrades with increasing size.
“A lot of the unique properties are coming from nano-scale organization,” she says. “If you want to make them larger, those are going to become hard to control. When you go to larger scales you can’t enjoy the same degree of performance as the small samples.”
In spring 2016, she was awarded just under $380,000 to study scalable manufacturing of multi-functional polymer nanocomposites by the Office of Naval Research.
Yamamoto has worked extensively with carbon nanotubes (CNTs) as a potential conductive-coating nanomaterial for use in protecting airplanes from lightning strikes. These nanotubes were aligned, and thus become efficient electrical conductors, like tiny lightning rods. This approach could lead to considerable weight savings over the currently used metal mesh layer. She originally fabricated such material by first organizing the nanotubes and then infiltrating with a polymer; however, this method was not the most scalable. Now, she first mixes nanoparticles together with polymer, and then organizes the nanoparticles using external oscillating magnetic fields.