A methodology for remote microwave sterilization applicable to the Coronavirus and other pathogens using retrodirective antenna arrays

This paper describes an innovative remote surface sterilization approach that could be applicable to the new coronavirus. The process is based on the application of a liquid film on the surface or object under sterilization (OUS). A beacon signal is required to self-steer the transmitted power from the designed retrodirective antenna array (RDA) towards the OUS; once the liquid film reaches the required temperature, the sterilization can be considered complete. Results suggest that the process takes 5 minutes or less for an angular coverage range over 60 whilst abiding by the relevant safety protocols. This paper also models the power incident onto the OUS and results are consistent with full-wave simulations. A practical RDA system is developed operating at 2.5 GHz and tested through the positioning of a representative target aperture surface. Measurements, developed by sampling the power transmitted by the heterodyne RDA, are reported for various distances and angles, operating in the near-field of the system. To further validate the methodology, an additional experiment investigating virus deactivation through microwave heating was also reported using live Coronavirus (strain 229E). Possible applications of the method include the sterilization of ambulances, medical equipment, and internet of things (IoT) devices.