Microwaves could reduce spread of COVID-19

Researchers in the US are exploring the use of microwaves to reduce the spread of infection with COVID-19 and other aerosolised viruses.


Studies show that the COVID-19 virus may be contained in aerosols that can be generated through breathing, coughing, sneezing and talking. While scientists have previously explored the use of electromagnetic energy to deactivate flu virus in bulk fluids, less work has been done to understand the role of non ionising radiation, such as microwaves, in reducing the infectivity of viral pathogens in aerosols.

The team at the US Air Force Research Laboratory are aiming to better characterise the threshold levels of microwave energy needed to inactivate aerosolised viral particles with their new study, published in Review of Scientific Instruments. According to the researchers, they developed a set of experimental tools capable of presenting electromagnetic waves to an aerosol mixture of biological media and virus with the capability to vary power, energy and frequency of electromagnetic exposure.


“In this way, we believe our experimental design is capable of a fundamental investigation of a wide variety of inactivation mechanisms,” said the paper’s co-author John Luginsland. “This range of capability is especially important given the range of potential interaction mechanisms found in the literature.”

The AFRL team explained that the key portions of each system fit within standard biosafety cabinets, ensuring multiple layer containment of pathogens, and are designed to prevent release of microwave radiation into the laboratory environment. 

Conceptual schematic showing key portions of the viral aerosol microwave inactivation experiment. Credit: Air Force Research Laboratory

During initial experiments, researchers are reportedly exposing a coronavirus surrogate, bovine coronavirus, to a range of microwave waveforms at frequencies ranging from 2.6GHz to 7.5GHz. Co-author Brad Hoff explained that the bovine coronavirus is similar in size and configuration to human coronavirus, but is safe to humans. Experimental efforts may then proceed to using aerosols containing COVID-19 or other human-infecting pathogens if exposure to microwaves is found to be successful in reducing infectivity.

“If shown to be effective, the use of microwaves may enable the potential for rapid decontamination not currently addressed by ultraviolet light or chemical cleaning for highly cluttered areas, while potentially operating at levels safely compatible with human occupancy,” Hoff said.