Laser-induced graphene (LIG) air filters, developed in 2019 by a team at Rice University, have future implications for medical facilities, where patients face the constant threat posed by air-borne pathogens.
The coronavirus, which is spread by respiratory droplets, has offered sobering proof of the havoc such diseases can wreak, but it is far from the only risk these patients might face. In all, one of every 31 of them will contract an infection while hospitalized, a rate that is only expected to increase. Dr. James Tour, the chemist who headed the Rice team, noted that scientists have predicted that by 2050, 10 million people will die every year as a result of drug-resistant bacteria.
As Tour also told SciTechDaily, “The world has long needed some approach to mitigate the airborne transfer of pathogens and their related deleterious products. This LIG air filter could be an important piece in that defense.”
Tour and his team developed a self-sterilizing LIG filter that can trap pathogens and eradicate them with electrical pulses. Those pathogens (bacteria, fungi, spores, etc.) might be carried by droplets, aerosols or particulate matter, but testing showed that LIG — a porous, conductive graphene foam — was equal to the task of halting them. The electrical pulses then heated the LIG up to 662 degrees for an instant, destroying the pathogens.
The self-sterilizing feature could result in filters that in the estimation of Tour’s team last longer than those currently used in HVAC systems within hospitals and other medical facilities. They might also be used in commercial aircraft, he told Medical News Today.
Israel’s Ben-Gurion University of the Negev has taken LIG technology a step further and applied it to surgical masks. Because graphene is resistant to bacteria and viruses, such masks would provide the wearer with “a higher level of protection,” as the mask’s inventor, Dr. Chris Arnusch, told Medical Xpress.
Because of its antibacterial properties, graphene can be used in medical and everyday wearables. Manufacturers have also taken advantage of its strength, flexibility and conductivity to integrate it in a wide range of products, from touch screens to watches to light jackets.
As for LIG, it is a process discovered in Tour’s lab in 2014, and involves heating the surface of a polyimide sheet with a laser cutter to form thin carbon sheets. LIG also has many uses, whether in electronics, as a means of water filtration or in composites that can be used in building materials, automotive components, body armor, sports equipment or aerospace components.
Arnusch, who serves as senior lecturer and researcher at the BGU Zuckerberg Institute for Water Research (a branch of the Jacob Blaustein Institutes for Desert Research), cited water filtration as the inspiration for his work on surgical masks.
But because COVID-19 has offered such a grim reminder about the dangers of airborne illness, the air filters have garnered as much attention as any graphene-related application at present. It is compelling evidence of just how versatile (and valuable) graphene can be, and of what it might mean for our safety, and our future.