Handheld Coronavirus 'Killing' Device That Uses Ultraviolet Light Now Possible, Researchers Say

A device that is capable of "killing" novel coronavirus on surfaces by using high-intensity ultraviolet light is now possible, researchers say.

Breakthroughs in UV-transparent materials may help to produce UV LEDs at low cost and high quantity to rid surfaces of viruses, according to researchers from Penn State, University of Minnesota, University of Tokyo and Tohoku University, Japan.

A paper released Monday, published in Physics Communications, details how the team sought to find an LED electrode material sufficiently transparent to UV light—which until now was a major barrier to developing smaller virus-killing devices.

"You have to ensure a sufficient UV light dose to kill all the viruses," Roman Engel-Herbert, associate professor of materials science, physics and chemistry at Penn State, and a co-author on the academic paper, said in a statement. "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."

Targeting genetic material in microbes, UV light is known to destroy coronaviruses, and some experts believe it may also work on the novel coronavirus, the National Academies of Sciences, Engineering, and Medicine has said. However, experts stress that UV is known to damage human skin and exposure can prove dangerous to humans. It should only be used to disinfect objects or surfaces.

Penn State researchers said current materials absorb too much light in the UV range. Until now no viable alternative for a transparent conductive material was known.

The scientists said there are two main methods of disinfecting areas from bacteria and viruses—chemicals or ultraviolet exposure. Smaller devices would be useful for public spaces, where they are preferable to using harsh chemicals, they noted.

UV-emitting devices exist, but typically need a "mercury-containing" lamps, which require high power, have a short lifespan and are bulky, the team said. One possible solution was the creation of UV light emitting diodes with the new electrode material.

The team, which included materials theorists, said they recognized early on that a new class of recently discovered transparent conductors could be key to progress.

Predictive models suggested a material called strontium niobate would be suitable and tests designed to judge its performance as a UV conductor were positive.

"We realize that this breakthrough discovery potentially offers a solution to deactivate COVID-19 in aerosols that might be distributed in HVAC [Heating, ventilation, and air conditioning] systems of buildings," said co-author Joseph Roth, doctoral candidate in Materials Science and Engineering at Penn State, who contributed to the work.

Researchers said virus disinfection could prove useful for theaters, sports arenas and public transportation vehicles such as buses, subways and airplanes.

Last month, Pittsburgh International Airport announced that it was using autonomous cleaning robots equipped with ultraviolet light to help disinfect surfaces.

Their paper explains how strontium niobate—SrNbO3—was a key component. "The rare combination of high transmission and high conductivity of [strontium niobate] facilitates the improvement of existing UV LEDs," it reads.

The material enables "long lasting, high performance, portable and environmentally benign solid state lighting solutions for UV sanitation, biomolecule sensing, UV phototherapy and high sensitivity solar blind detector technology."

Evidence suggests that the novel coronavirus can linger on surfaces for "hours to days," according to the U.S. Centers for Disease Control and Prevention (CDC). "Cleaning of visibly dirty surfaces followed by disinfection is a best practice measure for prevention of COVID-19 and viral respiratory illnesses in households and community settings," it says. COVID-19 mainly spreads via respiratory droplets.

The use of UV light as a way to combat the virus gained mass attention in April after president Trump appeared to deem it as potential treatment for humans.

In a briefing, Trump suggested COVID-19 patients could be hit with a "tremendous" amount of "ultraviolet or just very powerful" light on their body or skin. He fueled controversy after claiming that disinfectant "knocks it out in a minute," asking "is there a way we can do something like that, by injection inside or almost a cleaning?"

The president's comments were criticized by medical experts. "Neither sitting in the sun, nor heating, will kill a virus replicating in an individual patient's internal organs," Penny Ward, a professor in pharmaceutical medicine, told the BBC.

For now, there is no known vaccine or cure for the infectious respiratory illness that has caused more than 100,000 deaths in the U.S., health experts say.

Ultraviolet lamp (Stock)
Stock photo: Germicidal ultraviolet lamp glows on a rough wall. A handheld device that is capable of “killing” novel coronavirus on surfaces by using high-intensity ultraviolet light is now possible, researchers say. iStock