Rice University researchers have developed self-sterilizing bacterial air filters using graphene. Workings of this novel air filter are published in the American Chemical Society journal ACS Nano.
This devise captures bacteria, fungi, spores, prions, endotoxins and other biological contaminants carried by droplets, aerosols and particulate matter. The filter then prevents the microbes and other contaminants from proliferating by periodically heating up to 350 degrees Celsius (662 degrees Fahrenheit), enough to obliterate pathogens and their toxic byproducts.
The filter utilizes laser-induced graphene. This is a conductive foam of pure, atomically thin carbon sheets synthesized through heating the surface of a common polyimide sheet with an industrial laser cutter. The process discovered by Tour’s lab in 2014 has led to a range of applications for electronics, triboelectric nanogenerators, electrocatalysis, water filtration and even art.
The lab tested LIG filters with a commercial vacuum filtration system, pulling air through at a rate of 10 liters per minute for 90 hours, and found that Joule heating successfully sanitized the filters of all pathogens and byproducts. Incubating used filters for an additional 130 hours revealed no subsequent bacterial growth on the heated units, unlike control LIG filters that had not been heated.
This filter provides use case scenarios especially in hospitals, schools, and passenger aircraft. Although similar air filtration systems are available currently, self sterilization of filter holds promise as it can reduce number of filters used and their replacement frequency there by providing a cost reduction. However further research is required before this product is fully implemented.