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.”
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.