You’ve probably noticed over the past two months how hard it is to speak with people when half their face is hidden. You can’t hear them very well or make out their facial expressions. And for some segments of the population — like children, the elderly, and the hearing impaired — the masks are a major obstacle to communication. That’s why a team of researchers from EPFL’s EssentialTech Center  and Empa (the Swiss federal materials-science center) has been working for the past two years on a completely transparent surgical mask. They have now finalized a biomass-based material to fabricate the masks and have created a startup called HMCARE to market them. After completing a CHF 1 million fundraising round, the company is now ready to develop the industrial process. Discussions are under way for a planned market launch in early 2021.

Transparent, Resistant, and Eco-friendly, with Just the Right Level of Porosity

Called HelloMasks, the transparent masks are intended to replace the tri-fold green or white ones that healthcare workers usually wear (and that have been polluting our sidewalks since the start of the pandemic). This protection could be worn by anyone, although they’re designed primarily to make the contact between caregivers and patients less impersonal. The idea came when Klaus Schönenberger, the head of EPFL’s EssentialTech Center — whose mission is to help transfer modern technology to developing countries — was working in western Africa during the 2015 Ebola outbreak.

“It was touching to see that nurses — covered from head to toe in protective gear — pinned photos of themselves on their chests so that patients could see their faces,” he says. The following year, Schönenberger was approached by Thierry Pelet, now the CEO of the start-up, and Sacha Sidjanski, a project manager at EPFL’s School of Life Sciences, with an initial design for a transparent mask. Recalling his experience in Africa, Schönenberger didn’t hesitate for a second. Pelet and Sidjanski were inspired by Diane Baatard, a former storyteller at the Geneva University Hospitals, who found it unfortunate that the seriously ill children she entertained couldn’t see her facial expressions as she spoke.

The transparent masks are intended to replace the tri-fold green or white ones that healthcare workers usually wear. (Credit: EPFL)

EPFL’s EssentialTech Center, working with Empa, has developed a fully transparent surgical mask that will soon be produced on an industrial scale. The team has created a startup called HMCARE to market the masks and has already raised CHF 1 million to develop the manufacturing process.

“Looking online you can find prototypes of masks that are partly transparent, but they’re just normal masks with some of the fabric replaced by clear plastic,” says Pelet. Since that plastic isn’t porous, however, it makes it hard for the wearer to breathe and fogs up easily. The EPFL and Empa researchers spent two years finding the right combination of transparency, resistance and porosity. They eventually came up with a membrane made from a polymer developed specifically for this application. The polymer fibers are just 100 nm apart, which is the same spacing used in conventional masks — small enough to filter out viruses and bacteria but large enough to let air through.

Because the new masks will be disposable for optimal efficacy, like existing surgical masks, the researchers focused from the start on finding a material that was either recyclable or biodegradable. “Our material is made at 99 percent from a biomass derivative, and we’ll keep working on them until they’re completely eco-friendly,” says Pelet.

The material is made using a common method called electrospinning, where an electric force is used to draw polymer fibers. However, the researchers adapted the method slightly for large-scale production. The material will be generated in spools from which individual masks can be cut and assembled. While the research team initially planned to fabricate their masks in Asia, they’re now considering keeping production in Switzerland. A number of companies — including HMCARE — are planning to build surgical-mask plants in the country to meet the surging demand caused by the pandemic. Pelet is in talks with several other businesses and public-sector organizations.

The surging demand also made fundraising a lot easier for the startup. “We could’ve raised more than CHF 1 million, but we don’t need the extra money right now so we turned it down,” says Pelet. The research on HelloMasks was initially funded by close to a dozen non-profit organizations and later by an Innosuisse grant. While the masks will first be sold to the medical community — dentists have also expressed an interest — they may eventually be marketed to the general public. The product launch could take place in early 2021.