Custom face shields aim to block droplets, tackle COVID-19 for football players
September 2, 2020
Football is a contact sport. Tackles and huddles and scrimmages position players inches from each other’s faces over and over again. Close contact is integral to the game, but it’s also the primary way that SARS-CoV-2, the novel coronavirus that causes COVID-19, finds new hosts, carried in respiratory droplets released by someone with an infection.
Could a customized face shield block those droplets and help protect football players the way standard face shields help protect medical workers?
Stefan Duma, the Harry Wyatt Professor of Engineering and the founding director of the Virginia Tech Helmet Lab; Mike Goforth, the associate athletics director for sports medicine; and Mark Rogers, the chief medical officer for Virginia Tech Athletics, have spent years working to reduce risk in football. Now, the group whose long collaboration has pushed the frontier of head-impact research in collegiate sports and produced the respected Virginia Tech Helmet Ratings has turned their attention to reducing the risk of COVID-19.
By early summer, it was clear to the trio that the pandemic would still be a factor for the fall football season. Practice was set to start in August.
“We only had a couple of months to put together a solution,” Duma said. “Developing and testing an entirely new face shield on that timeline took commitment and engagement from multiple areas, but the collaborations that were already in place gave us a strong foundation and allowed us to mobilize quickly.”
As university research flickered back to life after its early-pandemic hiatus, the team started designing. Duma, who also directs the university’s Institute for Critical Technology and Applied Science, led the project, working closely with Goforth and Rogers. Mechanical engineering professor Alex Leonessa and his students contributed expertise they’d accumulated over months of designing and manufacturing face shields for frontline workers. Matt Hull, a researcher at the Institute for Critical Technology and Applied Science, helped steer the design as an engineer with the additional perspective of a former college tight end.
“I couldn’t stand visors when I played, so that drives the way I think about interventions,” Hull said. “I’ve been thinking about how to make them as painless as possible for the players. They may not be perfect solutions, but they’re effective and likely reduce risks of on-field transmission.”
The team worked their way through multiple designs over the early weeks of the project, working long hours and weekends to compress months of work into weeks. Football players came in every day to test out prototypes, weighing in on visibility and breathability. Ultimately, the design that met their criteria of efficacy, wearability, and ease of production was a deceptively simple solution: a shield pieced together from two visors. The upper half is a commercially available visor — in fact, many players already wear one for eye protection. A second visor, turned upside down and trimmed to fit the helmet, sits directly below the first one and covers the lower half of the face.
“Since Duma’s research team first installed impact sensors in the helmets of Virginia Tech football players back in 2003, Virginia Tech has been at the forefront of finding ways to enhance helmet technology,” Goforth said. “Their work on these face shields is yet another example of their willingness to use the latest materials and science to make a positive impact on the game of football. Along with Chief Medical Officer Mark Rogers, head coach Justin Fuente, and our players, we all appreciate their ongoing commitment to innovation and research that will benefit football players, as well as many others.”
The critical test, of course, was how well the shield performed as a droplet barrier. It just so happens that Hull’s area of engineering expertise is exposure to very, very small particles. Respiratory droplets vary widely in size, but many are hundreds to thousands of nanometers across. Detecting particles this small requires highly specialized equipment. Hull, who earned master’s and doctoral degrees from Virginia Tech in civil and environmental engineering, runs a local company called NanoSafe that focuses on managing exposure to nanoscale particles (typically in contexts like laboratory containment systems or emissions from consumer products).
The test setup Hull developed for the shield was inspired in part by a line of scrimmage, where players face each other across a football-sized gap. The time players linger here, Hull reasoned, might make this one of the riskiest formations for coronavirus transmission. With that as a real-world reference point, Hull reworked a typical face-shield testing protocol, conducting spray tests in NanoSafe’s cleanroom in the Corporate Research Center. The tests measured how many droplets could escape from a helmet fitted with the dual-visor shield, and how many could make it in from outside.
The research team was particularly interested in droplets smaller than 300 nanometers, the standard that’s used to certify the N95 masks used by frontline workers. The dual-visor shield blocked more than 99 percent of them. Meanwhile, impact tests in the helmet lab verified that the visors could withstand the forces that regularly pummel players' helmets on the field.
As the players put in more hours in the visors, they’re offering feedback that the researchers are using to fine-tune the design.
“It started off with a full visor on the bottom half and the top,” said safety Divine Deablo, who’s been wearing the shield. “First couple days it was good, then it got a little humid, so it was harder to breathe and it got a little foggy. Recently, they cut part of the bottom half so it still covers the mouth but I have more air coming through so I can breathe and it’s a lot better.”
A Kelly Hall conference room, vacated as meetings have migrated to Zoom, now holds a makeshift assembly line where the shields are trimmed, filed, and installed in helmets for any Virginia Tech football player who wants one. The team is working on streamlining the process so it can be scaled up and has shaved the production time down to about five minutes per shield. They’re also exploring the idea of treating the shields with a coating developed by a Virginia Tech chemistry professor that has inactivated the coronavirus in lab tests.
Like the original head-injury research, which has attracted an international audience and driven the development of better sports equipment, Duma hopes their work on the face shield can have an impact far beyond the Virginia Tech gridiron. He has already shared the design with the NFL and the ACC, and is considering how the group might help make visors for players at other schools.
“From the beginning, it was important to us to make our design open-source and easy for other people to replicate,” Duma said. “We’ve intentionally kept it simple. We’re using readily available materials that are compatible with the equipment players are already using.”
The ability to come up with a solution that was effective, reproducible, and comfortable for players to wear in less than two months is a testament to what happens when talented people join forces. Taylor Langon, a concussion research coordinator in the sports medicine department, shuttled back and forth constantly between different sites, cheerfully managing equipment handoffs and collecting feedback from players. Craig McNally, the engineer behind the design of the Helmet Lab’s unique impact rigs, helped the team figure out how to craft the shields and scale up the production.
“It definitely feels like a ‘dream team’ of engineers, scientists, and athletic staff,” Hull said. “It has been amazing to see the level of care that the athletic training staff have for the athletes. They’re looking at everything, processing the same emerging data and science that we are, seeking help when needed, and taking thoughtful steps to implement protective strategies in real time.”
In immediate response to the COVID-19 pandemic, Virginia Tech faculty, staff, and students have initiated numerous research projects relevant at local and global scales. Learn more from the Office of the Vice President for Research and Innovation.