Chemical Modulation Schematic
A schematic showing how a chemical modulation layer “sanitizes” the face mask wearer’s respiratory droplets. (Credit: Jiaxing Huang/Northwestern University)

A new concept for a mask aims to make the wearer less infectious. The central idea is to modify mask fabrics with antiviral chemicals that can sanitize exhaled, escaped respiratory droplets.

By simulating inhalation, exhalation, coughs, and sneezes in the laboratory, the researchers found that nonwoven fabrics used in most masks work well to demonstrate the concept. A lint-free wipe with just 19 percent fiber density, for example, sanitized up to 82 percent of escaped respiratory droplets by volume. Such fabrics do not make breathing more difficult, and the on-mask chemicals did not detach during simulated inhalation experiments.

The approach significantly reduced infectiousness, even with masks made from loosely woven fabrics, such as gauze. The team wants to design a mask based on winding animal nasal passages to trap droplets created by coughs and sneezes and then inactivate the trapped viral particles with copper filters.