Self-disinfecting mask: germ-free at the push of a button

Disinfection and masks are essential to prevent the spread of Covid-19. Swiss scientists from ZHAW and Osmotex AG have now combined the two and developed a mask that disinfects itself at the push of a button. It is to be launched on the market as early as this spring.

In an interview with MEDICA-tradefair.com, Prof. Chahan Yeretzian talks about how sportswear gave the developers the idea of a self-disinfecting mask, how self-disinfection works and where it could also be used.

Prof. Yeretzian, how did you come up with the idea of developing a self-disinfecting mask?

Prof. Chahan Yeretzian: About three years ago, in a project with the company Osmotex, we investigated new types of textiles for athletes that actively transport sweat to the outside and thus keep the body dry. During development, we discovered that a number of reactive oxygen species (ROS) are formed in the process, which was not the way it was intended. At the start of the corona pandemic in January last year, the chief technologist at Osmotex, Trond Heldal, remembered precisely this side effect and patented the new idea of ROS sterilization for textiles. A joint research project was then initiated by ZHAW and Osmotex, supported by federal funds. We wanted to find out how many ROS are generated, whether they can be controlled and dosed, and how this can be accommodated in a textile, for example a mask. The fact is that this electrochemical effect inactivates pathogens - both viruses and bacteria – within minutes. The principle of using ROS to render viruses harmless is already being used in swimming pools, for example.

What is the mask made of? How does the self-disinfection work?

Yeretzian: The mask consists of three layers: two conductive textile layers and an insulating fleece in between. A small battery of 0.6 volts applies an electrical voltage between the two conductive layers. Together with some moisture, which is generated by breathing or by moistening at the beginning, and the oxygen in the air, this field then generates ROS, such as oxygen peroxide and other compounds, which then kill the viruses, but also bacteria, as a chemical weapon, so to speak.

What are the advantages of such a mask?

Yeretzian: The masks known today only retain the viruses by filtering. However, there are already masks on the market that passively inactivate viruses with the help of certain coatings on the textiles. The disadvantage, however, is that inactivation is slow and incomplete. Our masks also have these two functions – filtering and passive inactivation. But in addition, we have a third level of protection: active inactivation at the push of a button. This electrochemical sterilization can be used by the wearer in certain situations, for example, when the person is in an environment where there is a high risk of infection, such as on public transport or in hospital.

What needs to be taken into account during use?

Yeretzian: The masks clean themselves. This is done with the integrated mini-battery, which should be recharged regularly. In addition, the textile can be washed, but not too hot or too aggressively. So the masks are sustainable in the sense that you can use them again and again. In general, care should be taken not to treat the masks too roughly. Then they are estimated to last for half a year.

To what extent does such a mask help to contain the corona pandemic?

Yeretzian: It helps because it also offers a very high level of self-protection. Many masks primarily protect the environment. The air the wearer breathes is filtered. But if the mask of an infected person is contaminated, it poses a risk of infection. By allowing our now-developed masks to clean themselves repeatedly and at the push of a button, they are prevented from becoming such sources of contamination. In addition to masks, the self-disinfecting technology can be applied to all kinds of textile surfaces, such as armrests or seat covers in public transportation, or protective clothing in hospitals and other places of operation, as well as for security forces.

Approximately when should the mask be launched on the market? How much will it cost?

Yeretzian: It will be launched in the spring. We still want to optimize the battery – it should be smaller. The inventor and industry partner Osmotex is also expecting very high demand, so they will have to increase production capacity.

The final price will depend in particular on the number of units produced. The masks will not be sold by Osmotex itself, but will be purchased in bulk from wholesalers who will then distribute them to hospitals, pharmacies and other medical institutions. We are already in talks with intermediaries here.