Painting with light

LEDs can help grow plants, but LEDs that emit UV can also stop things growing. UVC emitting LEDs have all sorts of potential uses from sterilisation to applications in medicine, but one use could further enhance the technology’s green credentials as a non-toxic energy saver.

Problems for shipping

Marine growth on the underside of boats, known as biofouling, causes problems for shipping by compromising the vessel’s performance and interferes with propellers, sensors and other equipment. The conventional solution was to manually remove the build-up of growth or use anti-fouling coatings, some of which are toxic. A solution to this age-old problem would lead to a saving in the amount of fuel shipping needs to consume and help prevent the accumulation of poisons in the ocean.

Sterilises the surface

The build-up of barnacles and the like depends on the initial formation of a biofilm made up of bacteria and other microbes. What the LEDs can do is emit short-wavelength UVC that kill the microbes and effectively sterilise the surface.

Practical applications

The idea already has practical applications in protecting instruments under the surface. Lager scale treatments for the underside of ships are under development by AkzoNobel, a Dutch multinational who produce paints and other coatings. They claim that “the fully biocide-free solution will provide groundbreaking performance and offer complete fouling prevention to the hulls of ships and boats. The total control of biofouling represents a substantial economic and environmental benefit, and when realized, the impact of this new technology on vessel owners and operators will be hugely significant”.
If successful, this protective coating integrating UV LEDs could seriously improve the sustainability of shipping.