Biofouling of ship hulls, primarily caused by the accretion of marine crustaceans such as barnacles and tubeworms, poses a significant impediment to ship performance. On its course, a ship can add barnacle weight at 150 kgs per square meter in as little as six months. The Naval Surface Warfare Center, Carderock, estimates that vessel speed is reduced by up to 10 percent from biofouling, which can require up to a 40 percent increase in fuel consumption to counter the added drag.
ONR is investing in environmentally friendly coatings for ship hulls to prevent biofouling organisms from interfering with a ship’s hydrodynamic performance. Previous biofouling solutions have included the use of biocides, which use toxins to kill organisms that try to attach to the hull.
ONR’s research has yielded signifi cant progress in the development of two powerful, nontoxic biofouling prevention agents. The Sharklet™ coating, developed in partnership with researchers at the University of Florida, mimics the inherent texture and antimicrobial properties of shark skin. Zwitterionic or mixed charge compunds, developed in partnership with the University of Washington, manipulate surface environments at the molecular level to prevent proteins from binding to the ship’s surface.
By reducing microorganism build-up, both coatings stand to substantially improve ship performance and fuel effi ciency, while dramatically cutting fuel and maintenance costs. These coatings may also also reduce the transport of invasive species via ship hulls and eliminate the discharge of biocides into surrounding environments
Additionally, researchers have determined that the ONR-funded marine biofouling prevention technologies also inhibit the growth of disease-causing bacteria. This unique attribute may have applications in the design of medical devices or hygienic surfaces found in hospitals and food preparation areas.