Chicken pox, smallpox, measles. If you've ever had any of these sicknesses in your lifetime, airborne bacteria are likely to blame. Aside from these, tiny particulate matter in the air is likely a suspect aggravating your asthma and allergic rhinitis. While some are mere annoyances, some airborne pathogens can mean the difference between life and death.
Mostly invisible to the naked eye, several airborne pathogens are the cause of many of our common ailments. While there are several ways of removing these, filtration is one of the most common methods of doing the job. One of the downsides of this technique is that constant maintenance and filter replacements are needed every so often to maintain peak performance.
Aside from filtration, ultraviolet light disinfection is also widely used as a technique to destroy bacteria; however, the byproducts of microorganism death are not entirely removed, allowing them to proliferate over time.
Searching for new ways to innovate in this field, researchers from Rice University and the Texas A&M Health Science Center have just recently published a paper that looked into using laser-induced graphene as a material for filtering airborne pathogens. The material looks to be very promising for this particular application because of several pros.
Graphene is made from carbon, the same element that the graphite in pencils is made of. What makes graphene special is its structure: a single two-dimensional layer of carbon atoms (imagine a chicken wire mesh) which makes it both very thin yet very strong, around 100 times stronger than steel. Aside from its astonishing strength, it has a host of other interesting properties, but the one important thing to note is its very high conductivity, which allows electrical current and heat to pass through efficiently.
The filter material was created through subjecting a polyimide film, which provides structural integrity to the filter, to a CO2 laser. The result is called laser-induced graphene (LIG), a highly porous material that is thought to have inherent antimicrobial properties that prevent the accumulation of microorganisms.
While already difficult enough for bacteria to latch onto due to its antimicrobial behavior, periodically heating the material to high enough temperatures (quite easily done thanks to its conductivity), both bacteria and its byproducts are eliminated from the filter and essentially giving it self-sterilizing properties. In addition, LIG's porous structure is also highly suited to capturing large numbers of pathogens in the air.
In action, LIG is a highly effective filter material that is essentially self-sustaining and requiring less maintenance than conventional filters, saving costs over the long term.
The applications for this material are readily seen in the healthcare industry. With nosocomial infections (sicknesses acquired from hospital visits) affecting one in 10 people, these are often difficult to eradicate because of their high drug resistance. However, utilizing these LIG filters bypasses this factor and destroys these pathogens upon contact, providing an extra barrier of defense that could mean the difference in a patient's life.
