Researchers develop 'virus-killing' air filtration system

The multifunctional air filter is described in detail. Credit: Liron Issman / Dr Brian Graves
Cambridge scientists and engineers have developed a new nanomaterial for air filtration that is carbon-based and can capture and destroy various viruses. This includes animal coronavirus which is a close relative to SARS-CoV-2the disease that causes COVID-19.

A multidisciplinary team of researchers from Boies Group in the Department of Engineering and colleagues from the Department of Materials Science & Metallurgy tested the prototype. It is equipped with ultra thin carbon nanotube electrically conductive materials. The new conductive filter membrane allows simultaneous virus filtration and sanitisation via thermal flashes via resistive heat to temperatures above 100C. This deactivates viruses including betacoronavirus in just seconds.

Researchers say that the multifunctional filter is particularly effective in fighting viral spread in enclosed environments like hospitals, emergency vehicles, and leisure centers. It can be used either as a standalone unit, or as part of heating, ventilation and air conditioning (HVAC), filtration systems. Carbon reports the results of virus infectivity trials that were supported by theoretical modeling.

This filter is a new type of conductive filter mediums that enable electrical functionality. It can be mass produced and has a filtration efficiency and air permeability that match that of commercial HEPA filters. The filter effectively captures the respiratory liquid droplets, which are carriers of many viruses including coronavirus. These virus particles can be produced by breathing, coughing, and speaking, and they remain suspended in the atmosphere for hours. They migrate over tens to dozens of meters in confined areas. These respiratory particles are responsible for high infection rates in enclosed spaces and crowded areas.

The University's unique carbon nanotube process produced the material. It is also the pillar for the ANAM Initiative funded by the EPSRC. This initiative seeks to unlock carbon nanotubes' commercial potential.

Liron Issman, Ph.D. student said that the project provided the basis for several prototypes showing that the filter can purify air in a small space or ambulance in just 1020 minutes. Many industrial collaborations have been initiated with leading air filtration companies around the world to incorporate carbon nanotube material in state-of-the art applications to combat COVID-19, and other airborne pathogens.

Q-Flo Limited, an University of Cambridge spin-out company, is commercializing our unique process to produce more than 100,000 m2/yr of the membrane material. These conductive filtration materials have many benefits. They are low in flow resistance, high capture efficiency, and can be heated or sensed further.

Continue reading to find out which air cleaners are best for removing aerosols containing viruses.

Liron Issman and colleagues, Filtration via a hybrid carbon-nanotube active filter to remove viral aerosols, Carbon (2021). Information from the Journal: Carbon Liron Issman and colleagues, Filtration via a hybrid carbon-natube active filter of viral aerosols, (2021). DOI: 10.1016/j.carbon.2021.07.004