Development and Evaluation of a Fluidic Facemask for COVID-19 Transmission Mitigation

Abstract

A novel fluidic facemask, or Air-Screen, is described and demonstrated experimentally for protection against virus-laden aerosol and droplet infections, such as COVID-19. The Air-Screen employs a small, high-aspect-ratio, crossflow fan mounted on the visor of a filter-covered cap to produce a rectangular air jet, or screen, in front of the wearer’s face. A theoretical model, based on a weekly-advected jet in a crossflow, indicated its effectiveness against a wide spectrum of virus-laden aerosols and droplets. Qualitative flow visualization experiments, using a mannequin, clearly illustrated the Air-Screen’s ability to effectively block airborne droplets from the wearer’s face. Quantitative experiments to simulate droplets produced during sneezing or a wet cough, were propelled (via a transmitter) at an average velocity of 50 m/s at 1 m from the mannequin or a target. The Air-Screen blocked 62% of all droplets with a diameter of less than 150 µm. With an Air-Screen active on the transmitter, 99% of all droplets were blocked and when both mannequin and transmitter Air-Screens were active, 99.8% all droplets were blocked. In contrast to conventional facemasks, the Air-Screen is remarkably effective in protecting the wearer and others from an infected wearer.