NRL researcher optically measures aerosol particles smaller than a wavelength of light in real time

WASHINGTON – A research physicist at the U.S. Naval Research Laboratory invented a new method to create and optically measure gases with particles smaller than a wavelength of light.

Principal investigator Jake Fontana and his peers published the findings February 2019 and have a patent pending on their technique.

“We made an instrument which efficiently creates aerosols with nanometer-size particles. Because the particles are plasmonic, we can see them in real time,” Fontana said. “This opens up a new world in being able to study nanoparticle gases at the benchtop.”

Research physicist Jake Fontana stands next to the Nanoparticle aeRosoL (NRL) instrument at the U.S. Naval Research Laboratory. The benchtop instrument measures the behavior of gases with particles of nanometer size in real time. The ability to see tiny aerosols can advance research in meteorology and other fields. U.S. Navy photo.

Plasmonic materials -- such as gold, silver and platinum particles - contain oscillating electrons that couple efficiently to light.

Artists have been using plasmonics for centuries without knowing the term. Early photographs, called daguerreotypes, used silver iodide in processing. The application of silver in daguerreotypes created visible images because the small clusters of silver deposited had plasmonic properties.

Fontana’s team has previously worked on plasmonic materials in the liquid phase or on solid 2D surfaces, but turning them into homogeneous and stable gases is new.

“The tiny particles in aerosols have been very difficult to see in real time because they tend to couple poorly to light or are inhomogeneous in size and composition,” Fontana said. “Now that we can see how they interact with their environment, we can look at how they influence cloud formation, convection and other remote sensing applications.”

Researchers are already looking at how these tiny specks influence weather. Fontana’s paper also cites how aerosols linked to maritime traffic influence lightning and the intensity of storms at sea.

In addition to meteorological applications, understanding how nanometer-sized particles behave may also impact research in medical and microelectronics.

“It’s fantastic how quickly the team pulled this together,” Fontana said. “We’re excited to make this accessible for other labs for their work.”

Fontana’s pending patent was designated as 110326-US3 for the apparatus for generating and optically characterizing an aerosol. The Office of Naval Research funded this work.

The Nanoparticle aeRosoL (NRL) instrument invented by researchers from the U.S. Naval Research Laboratory measures the behavior of gases with particles of nanometer size in real time on the benchtop. The patent pending technique combines the capability to efficiently aerosolize plasmonic materials with an atomizer and, simultaneously, characterize them with a Herriott cell and infrared detector. The ability to see tiny aerosols can advance research in meteorology and other fields. U.S. Navy graphic by Jake Fontana.



About the U.S. Naval Research Laboratory

NRL is a scientific and engineering command dedicated to research that drives innovative advances for the Navy and Marine Corps from the seafloor to space and in the information domain. NRL headquarters is located in Washington, D.C., with major field sites in Monterey, California; Key West, Florida; Stennis Space Center, Mississippi, and employs approximately 2,500 civilian scientists, engineers and support personnel.