‘Zapper’ invention by Lehigh University and St. Luke’s enables hospital to decontaminate 600 masks per hour

The industrial-sized device designed by a team from Lehigh University and St. Luke’s University Health Network uses powerful ultraviolet light to kill the coronavirus, allowing the hospital to decontaminate and re-use N95 masks, which are in short supply because of the pandemic.

The machine can decontaminate 600 masks every hour, though the hospital hasn’t used it to full capacity.

St. Luke’s anesthesiologist Dr. Christopher Roscher knew as the pandemic progressed it would become more difficult to get personal protective equipment for medical workers. In late February, he started thinking about ways the hospital could decontaminate and reuse items like masks.

His research led him to studies on UV-C light, a range of ultraviolet light that has been shown to deactivate viruses and other pathogens by causing changes in their DNA. The challenge would be in creating a machine that could handle a large number of masks and evenly bathe them in ultraviolet light, ensuring they were decontaminated on every surface.

On March 22, Roscher reached out to Nelson Tansu, director of Lehigh University’s Center for Photonics and Nanoelectronics, to discuss the idea.

The two organizations joined forces through Zoom meetings and hundreds of emails, to design, fabricate, install and test the device, all within two weeks and while maintaining social distancing protocols.

The unit — 80 inches in diameter and 5 feet tall, with tubes of light surrounded by an octagonal metal cage — was engineered by Lehigh students and staff and transported in a pickup truck to St. Luke’s University Hospital in Fountain Hill, where it was assembled. Since April 5, Roscher estimates the hospital has processed 15,000 masks, including those used by staff at nursing homes and emergency responders.

It was Tansu’s 8-year-old son, Axel, who suggested an octagonal shape to make sure the masks were evenly exposed.

The goal was to use enough UV-C light to damage viruses and bacteria but retain the integrity of the N95 masks, which can be degraded over time by steam or chemicals. The masks are hung on a hinged frame that rotates, making sure both sides of the mask get a blast of sterilizing light that comes from up to 13 cylindrical bulbs at the center of the machine, Tansu explained.

Masks can be zapped five to 10 times before they lose their shape.

The technology is being used elsewhere to control the spread of the virus. Last week, New York City’s Metropolitan Transportation Authority in partnership with Columbia University announced plans to use UV-C lights to disinfect the agency’s trains, buses and work areas, according to the New York Daily News. Since the light is harmful in high doses, the subways will close from 1-5 a.m. for the cleaning. Columbia researchers are working on technology called “far UV-C” that could kill COVID-19 without harming people, making it possible to disinfect subways and buses while riders are aboard.

While decontaminating masks works during the pandemic, it’s no substitute for new equipment. Research is limited on how effective UV-C decontamination is, and masks vary in how they stand up to the procedure.

“Decontamination is a complicated process,” Hana El-Samad, who researches N95 sanitation as a professor of biochemistry and biophysics at the University of California-San Francisco, told The Associated Press. “Assessing how well it works and which N95 masks and models remain unaffected is an area of active research.”

Roscher said hospital staff members check their masks after each decontamination to make sure they still create a proper seal around their faces.

“One thing we always want to underline is that no one wants to reuse a mask that was intended for single use. Every health care network would like to have hundreds and thousands of these and so we were very careful to use evidence to guide us in our decision making and understand we are proceeding in a pandemic situation,” Roscher said.

Some hospitals have resorted to using bandannas, which don’t provide nearly the same level of protection, he said.

Tansu and Roscher applied for a patent for the zapper’s design, which they hope could be used by other hospitals and even food processing plants, universities and schools.

In the more than 20 years Tansu has been collaborating on projects, he said the “zapper” is the fastest he’s ever seen an idea come together.

“There was a selflessness, commitment and urgency to help the community from both sides,” Tansu said.