Toward nanotechnology-enabled face masks against SARS-CoV-2 and pandemic respiratory diseases.

Wearing a face mask has become a necessity following the outbreak of the coronavirus (COVID-19) disease, where its effectiveness in containing the pandemic has been confirmed. Nevertheless, the pandemic has revealed major deficiencies in the ability to manufacture and ramp up worldwide production of efficient surgical-grade face masks. As a result, many researchers have focused their efforts on the development of low cost, smart and effective face covers. In this article, following a short introduction concerning face mask requirements, the different nanotechnology-enabled techniques for achieving better protection against the SARS-CoV-2 virus are reviewed, including the development of nanoporous and nanofibrous membranes in addition to triboelectric nanogenerators based masks, which can filter the virus using various mechanisms such as straining, electrostatic attraction and electrocution. The development of nanomaterials-based mask coatings to achieve virus repellent and sterilizing capabilities, including antiviral, hydrophobic and photothermal features are also discussed. Finally, the usability of nanotechnology-enabled face masks is discussed and compared with that of current commercial-grade N95 masks. To conclude, we highlight the challenges associated with the quick transfer of nanomaterials-enabled face masks and provide an overall outlook of the importance of nanotechnology in counteracting the COVID-19 and future pandemics.