Fabrication of mask in PDMS for SARS-CoV-2

Denise Carvalho, Tiago Vale

Abstract

The new coronavirus SARS-CoV-2 (COVID-19) belongs to the family Coronaviridae and was first identified in December 2019 in China, in the city of Wuhan. With the spread of this virus, there was an urgent need to stop the pandemic. Thus, in order to minimize the spread, it was suggested to the world population to use masks, in order to control/minimize the proliferation of the virus made through the projection of droplets, which although invisible to the naked eye, are projected when a person sneezes, coughs, or even speaks. With the frequent use of a mask, another necessity was identified, to have transparent masks that allow people to identify each other. This need arose due to situations such as health professionals from hospitals and health centers, which patients were unable to identify the person who was treating them, as well as the health professionals were unable to identify themselves. To, solve these problems the project i9MASKS project proposes the creation of transparent masks using polymeric materials such as Polydimethylsiloxane (PDMS). Throughout this project, some of the properties of this polymer were studied and some manufacturing tests were carried out, so that at the end of the project, it was possible to develop a functional mask prototype that could be used by the target public mentioned above or even by other people who identify the same necessity. During this project, we have developed a planar mold of a mask where, afterwards, PDMS was poured and after curing, the two faces were joined with a PDMS wire in order to have a 3D PDMS mask. Studies have also been carried out to include possible filters within the mask, in order to ensure that they are possible to be replaced and the rest of the mask is reused and not wasted as is the case of the current masks. The inclusion of filters within the mask is an essential feature as they allow to improve the breathability and avoid the condensation existing inside them. The best location for these filters was also studied due to the air flow inside the mask. In this project, it was possible to produce a first 3D mask prototype in PDMS with a TNT filter incorporated and with elastics to support it.

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