A personal, handheld device emitting high-intensity ultraviolet light (UV) to kill the COVID-19 virus on surfaces is now feasible, according to new research from Penn State, the University of Minnesota and two Japanese universities.
While chemicals are commonly used to kill viruses, UV radiation exposure in the 200 to 300 nm range can also destroy viruses, making them incapable of reproducing or infecting. As such, UV light devices are in high demand. However, these devices are generally expensive because of the mercury-containing gas discharge lamp that is contained within them, which requires a lot of power. Additionally, these lamps have a short lifespan.
To overcome those obstacles, researchers believe if UV light emitting diodes (LED) were to be developed it would allow for a portable, long-lasting, energy-efficient and environmentally friendly solution that could be put into small form factors. However, while these materials exist, the electrode materials have to be transparent to UV light.
"You have to ensure a sufficient UV light dose to kill all the viruses," said Roman Engel-Herbert, Penn State associate professor of materials science, physics and chemistry. "This means you need a high-performance UV LED emitting a high intensity of UV light, which is currently limited by the transparent electrode material being used."
Currently, there is no good material choice for a UV-transparent conductor material. The key to developing a portable UV light device would be to find the right composition. Researchers found that a new class of transparent conductors using the material strontium niobite could be used and held promise for making UV LED materials possible.
"We immediately tried to grow these films using the standard film-growth technique widely adopted in industry, called sputtering," said Joseph Roth, doctoral candidate in materials science and engineering at Penn State. "We were successful."
Researchers believe this breakthrough is a critical step toward integrating the material into UV LEDs at low cost and high quality.
"While our first motivation in developing UV transparent conductors was to build an economic solution for water disinfection, we now realize that this breakthrough discovery potentially offers a solution to deactivate COVID-19 in aerosols that might be distributed in HVAC systems of buildings," Roth said.
The potential device could be used for virus disinfection in frequently populated areas such as theaters, sports arenas and on public transportation such as buses, subways and airplanes.
The full research can be found in the journal Communications Physics.
