A Self-sterilizing Plasma Filter for Eco-friendly Air Disinfection

Airborne pathogens including bacteria and viruses can pose a serious risk to public health and society. While air disinfection is crucial to prevent the transmission of such pathogens, conventional air disinfection based on HEPA filters is detrimental to the environment as they increase power consumption due to high pressure loss, and because they require replacement of single-use HEPA filters, resulting in pollution. The inability of HEPA filters to sterilize captured pathogens also poses the risk of pathogen releasement upon filter replacement. In this study, we present an eco-friendly plasma filter with reusable components and low energy consumption. The plasma filter integrates surface dielectric barrier discharges (SDBD) into an electrostatic precipitator for energy efficient pathogen capture and sterilization. The plasma filter can disinfect air at a flow rate of 600 l/min with a pressure loss of 0.1 Pa compared to that of ~250 Pa of HEPA filters. With 1 m/s airflow, the electrostatic precipitator can remove more than 5 log of airborne pathogens from the air to below the detection limit. When air flow is stopped, the integrated SDBD can reduce captured pathogens through oxidation by 2 log or more under half an hour. We expect this plasma filter to become a low-cost sustainable solution for air disinfection.