Side-Emitting Optical Fibers for Delivery of UV-C Light to Disinfect Key Bacteria in Space Station Water and Storage and Conveyance Systems

nbsp;Bacteria and biofilms pose health and operational challenges in human support systems. Germicidal UV-C disinfection using mercury-based lamps is a widely used technology that has numerous safety and reactor configuration disadvantages. Light emitting diodes (LEDs) are mercury-free alternative and other advantages are making them competitive and a lower cost alternative for disinfection (e.g. lack of warm up time, tunable radiation, long life of use).nbsp; However, a crucial technology barrier of LED disinfection is the small surface area that emits irradiation, which necessitates arrays of many LEDs within even the smallest reactor, and thus has been a major limitation to their adoption. We propose a means of increasing the irradiation area of LEDs by gt;100x through the development of side-emitting optical fibers (SEOF), essentially creating UV-C germicidal flexible glowsticks which can be bundled together with tens of optical fibers delivering light from a single LED. Currently only visible light SEOFs are commercially available. To overcome this wavelength dependent barrier, we recently discovered a nanotechnology-based solution to achieve side-emission from optical fibers in the UV-C range. This is achieved by coating an optical fiber in a new and novel way using shape-, size-, and surface chemistry modified silica nanoparticles that create light-scattering centers on the surface of the fiber.nbsp; The coated fiber is then overlaid with a UV-C transparent polymer that protects the fiber and prevents nanoparticle release into water and allows germicidal light to enter the water. This STTR proposal outlines a detailed work plan to develop this nanotechnology solution from the proof-of-concept phase to pre-design phase.