We want you - researchers - to stay safe! But we also know, researchers and people from academia sometimes are a bit short in money/funding. So you might come to the idea to recycle face masks. Let's share some insights here:
Face masks are generally not suitable for reuse. This is because it has a built-in filter that can be damaged. The rubber bands can also suffer. Since there is currently a supply shortage of face masks in many countries like Switzerland, emergency strategies must be developed for more resource-saving use. Corresponding guidelines are given below (Source:  Robert-Koch-Institut, 14.04.2020: https://tinyurl.com/sy97uro)
When reusing it, please note that...
the removal of the mask must be carried out in such a way that contamination of the mask (especially the inside) or contamination of the face is prevented, e.g. by prior hand or glove disinfection or appropriate glove management (e.g. multiple gloves)
after taking off the mask, it should be kept dry in the air (not in closed containers!) and stored temporarily so that contamination of the inside of the mask and carry-over to other surfaces is avoided
a demarcated area should be defined to provide a safe place for the mask that is not accessible to the public so that it can be reused
the gloves must be disposed of properly and/or the hands disinfected after manipulation of the mask - the used mask can be clearly assigned to a person in order to prevent it from being worn by other persons (e.g. marking the masks on the retaining strap)
the used disposable mask cannot be cleaned or disinfected with disinfectant, as this may have a negative effect on the functionality of the mask
when putting on the mask again, care must be taken to prevent the pathogens from spreading from the contaminated outer surface to the inner surface. Touching the inside of the filter fleece should therefore be avoided
hygienically clean, unused gloves are to be worn when reattaching and the gloves are to be disposed of before renewed patient contact
Masks whose inner surface may have been contaminated by handling errors must not be used - the place where the temporary storage took place must be properly disinfected immediately after removal of the mask.
Info source:  Robert-Koch-Institut, 14.04.2020: https://tinyurl.com/sy97uro
Instructions for microwave sterilization:
2-minute total exposure time at a power setting of 750 watts (maximum power). Two small vessels arranged side by side (in the above-mentioned study of 11.7 cm x 8.0 cm x 5.0 cm each), each filled with 50 ml tap water at room temperature (~ 20°C). FFP-2 mask is placed face down on the pipette tip boxes. FFR samples are dried for 1 hour between each exposure. This should not weaken the filter effect.
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Source:  Journal of Engineered Fibers and Fabrics, Evaluation of Multiple (3-Cycle) Decontamination Processing for Filtering Facepiece Respirators. Michael S. Bergman et al. https://tinyurl.com/yb49esed