UV-C surface disinfection: minimal physics considerations, dynamic vs static light sources, and simulations insights

Ultraviolet-C light (UV-C) has been widely used for disinfecting food, water, air, and environments. The use of robots to perform environment disinfection has been considerably researched in recent years, especially after the COVID-19 pandemic. However, the advantages of dynamic UV-C light sources are not well discussed in the literature. This study aims to demonstrate the advantages of using dynamic UV-C sources instead of stationary sources and discuss the appropriate lamp distances and speeds. Through simulations, comparisons were made between the areas covered by a dynamic and stationary UV-C source in a given time frame. The results demonstrate that a punctual dynamic light source in a simple rectilinear movement can cover an area over 66% greater than the best case of a static source in the same time budget. Additionally, this work highlights the importance of considering the incidence angle, the calculation of the ideal distance for a static point lamp, and the effects of using inadequate simulation resolution. Properly calculating the speed and distance of the UV-C light source can reduce the application time and, consequently, the energy consumption and associated costs.