RAPID: Fluid Dynamic Driving Mechanisms of Airborne Pathogen Transmission and Control

Project: Research project

Project Details


Airborne transmitted pathogens such as COVID-19 have caused large scale infections, death, health system overloads, and severe economic damage. Such airborne transmission paths can be associated with droplets ejected from natural human respiratory functions such as sneezing, coughing, speaking, and breathing. Even in the context of social distancing and face masks, there are several essential functions associated with hospitals, grocery stores, transit, and other essential confined workplaces that force interactions and fuel pathogen transmission. One potential method to reduce the transmission of airborne pathogens is to reduce the number of small droplets formed from the human respiratory function. It is generally known that small droplets (such as fog, mist, etc.) can remain suspended for long time periods. Such droplets enable transmitting pathogens for long time periods. Since large droplets (such as rain) are prone to fall from the air, pathogens in these droplets are less susceptible to airborne transmission paths. The aim of this research is to alter the host's fluid properties such that droplets formed during human respiratory functions remain larger, travel shorter distances, and fall reducing the propensity for airborne transmission.

The project seeks to quantify the droplet character formed during human respiratory function when the host's saliva properties are altered. Simple fluids-related solutions associated with altering the fluid properties of the host such as formulated confections (lozenges/gum/candy) will change saliva droplet breakup modes resulting in larger droplets that travel shorter distances and fall. The aim is to understand how fluid properties can reduce metrics associated with a pathogen's airborne transmission path. During the human respiratory function, droplets are formed through complex processes driven by a pulsed, turbulent jet with many underlying interfacial instabilities. These processes have not been studied from the aspect of altering the host's salvia fluid properties. The project will develop this knowledge gap using a combination of experiments and numerical predictions oriented around answering three specific studies: (i) Understanding the role of viscosity and surface tension in droplet characteristics, (ii) Evaluating how aerating saliva alters droplet characteristics, and (iii) Determining safe compounds that reduce airborne transmission while remaining comfortable to a person. In addressing these scientific questions, this effort aims to develop a new tool to reduce the transmissibility of COVID-19 (and other airborne pathogens). The effort is tailored to inform the public, scientists, and engineers (through press, fast-track publications, and professional meetings) of the developed science within a timeline that enables product development and wide-scale implementation that supports the 2020 COVID-19 pandemic.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Effective start/end date5/15/204/30/22


  • National Science Foundation: $200,000.00


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