RAPID: A physics-based model for droplet drying on varying surfaces and changing seasonal conditions and the implications for COVID-19 survival

Engineering - The COVID-19 outbreak has resulted in enormous loss of lives and economic damage. Seasonal return of the coronavirus (SARS-CoV-2) will be even more devastating. One of the primary ways that SARS-CoV-2 appears to spread is through people touching surfaces with virus-laden droplets. Virus survivability on surfaces varies greatly by droplet size and composition, surface material and texture, and the ambient temperature and relative humidity. These factors impact the concentration of salt and other solutes in the process of droplets drying on surfaces, which strongly influences the survival of viruses in the droplets. This project will address survivability of viruses inside droplets and its relationship to droplet size, type of surface and ambient conditions representing seasonal variations. The team will especially seek to understand conditions under which virus survival in surface-adherent droplets is diminished. This information is crucial for public health officials, virologists, and other experts working on disinfection efforts to control and mitigate current and future COVID-19 outbreaks.

This project will bring together an interdisciplinary team of engineers, virologists, and infectious disease experts to understand the mechanisms that determine virus survival/annihilation on different surfaces under varying seasonal conditions. The research plan combines computer simulations and experiments to reveal what happens inside droplets under conditions specific to COVID-19 scenarios. More specifically, this project will study the thermal and mass transport processes that occur in droplets drying on various surfaces. Project results will include quantitative information on the solute (salt, protein) concentration-time pathways in the interior of virus-carrying droplets drying on surfaces. These pathways will be quantified as functions of droplet size, composition, ambient temperature and relative humidity, and surface characteristics. Novel laser and chemical treatments of surfaces will be employed to modify hydrophobicity and hydrophilicity over a wide range to examine the effect of such modifications on droplet drying processes. This project will therefore reveal what types of seasonal conditions and surface modifications will contribute to diminished survival of viruses within droplets. The project team will transition project results to experts who study methods to deactivate viruses. Arming them with precise knowledge on the thermochemical conditions faced by the pathogens within drying droplets will enable them to focus attention on effective disinfection techniques.


This project is jointly funded by the Thermal Transport Processes program and the Established Program to Stimulate Competitive Research (EPSCoR).

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.