First transparent surgical mask goes into production

Visible smile: The transparent Hello-Mask also allows non-verbal communication between patients and nursing staff. (Visualization: EPFL)

The transparent "HelloMasks" are intended to replace the tri-fold green or white ones that healthcare workers usually wear. 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.

Empa researcher Giuseppino Fortunato and his team from the Biomimetic Membranes and Textiles Lab in St. Gallen worked on the material development for the Hello-Mask. Image: EPFL

“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 Empa and EPFL 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. "We can produce fine electrospun membranes with a pore size of about 100 nanometers," explains Empa researcher Giuseppino Fortunato from the "Biomimetic Membranes and Textiles" lab in St. Gallen, who developed the material together with Empa researcher Davide Barana. The architecture of the fibers creates extremely small gaps that allow air to pass through but hold back viruses and bacteria.

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 masks are made at 99% from a biomass derivative, and we’ll keep working on them until they’re completely eco-friendly,” says Pelet.

The polymer fibers of the masks make the membrane appear transparent, but keep pathogens away. Image: EPFL

The material is made using a process called electrospinning, where an electric force is used to draw polymer fibers. Now, 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 local, here 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.

Thierry Pelet, CEO HMCare (left) and Klaus Schönenberger, EPFL. Image: EPFL

The surging demand during the Corona pandemic also made fundraising easier for the startup. 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.