Impact of mucus rheology on exhaled droplet dispersal and COVID-19

The main transmission mode of the COVID-19 disease is through virus-laden aerosols and droplets generated by expiratory events, such as talking or sneezing. While the aerodynamics of such droplets have been the main focus of human studies, very little is known about their final deposition. To address this, we investigate mucosalivary dispersal and deposition onto horizontal surfaces corresponding to human exhalations with physical experiments under still-air conditions. Synthetic fluorescence tagged sprays with size and speed distributions comparable to human sneezes are observed with high-speed imaging. We systematically vary the rheological properties of the mucosaliva corresponding to healthy and non-healthy adults. Upon generating droplets with a synthetic sneeze, we measure its volumetric spatial-temporal dynamics on a horizontal surface. The results from this study will provide insight on how infectious diseases spread and further inform new strategies for social distancing.