A group of researchers led by University of Massachusetts Amherst engineers have created ultraviolet (UV) rays-emitting glass that can reduce 98% of biofilm from growing on surfaces in underwater environments, as reported in the journal Biofilm. Biofilm is a slimy layer of various types of microorganisms that grows on wet surfaces. "If you look down your sink and touch the inner side of it -- that slimy substance is biofilm," describes Mariana Lanzarini-Lopes, assistant professor of civil and environmental engineering at UMass Amherst, and a corresponding author on the paper. Biofilm is a significant issue for underwater applications. The United States Navy estimates that biofilms cost its fleet between $180 and $260 million annually. Biofilm growth on all underwater surfaces increases a ship's drag and subsequent fuel usage, as well as corrosion damage on ships or oceanographic equipment. Biofilm can also fog up windows used for cameras and other sensing devices that rely on transparency, and transport non-native species across the seas. Current solutions for dealing with biofilm rely on chemical agents like biocidal coatings to kill the organisms or nonstick coatings to prevent biofilms from attaching in the first place. However, these methods can have negative effects on the ecosystem and only last for a short duration. As an alternative to these chemical methods the UMass Amherst team, with funding from the U.S. Office of Naval Research (ONR), developed biofilm-resistant glass using UVC radiation, the shortest and most effective at disinfecting wavelength of UV radiation. Lopes's lab has already demonstrated that UV side-emitting optical fiber can distribute UVC radiation in small channels, like medical equipment (i.e. endoscopes, catheters and respirators), home devices (coffee makers and refrigerators) and water storage/distribution systems (pipes, bladders, membranes) to inactivate pathogenic organisms and prevent bacteria... |