Large scale, Low Temperature, Microplasma UV Lighting Tiles for Water Purification and Sterilization

Eden Park Illumination, Inc. is pursuing the development and commercialization of large arrays of microcavity plasmas capable of generating light in the vacuum ultraviolet and deep ultraviolet wavelength ranges (VUV and UVC espectively), but in a slim and flat form factor. Ultraviolet is well known to be efficient in enabling a number of chemical processes, and is particularly effective for disinfection. The ability of deep UV and VUV radiation to neutralize pathogens (bacteria, viruses, and cysts), drugs (hormone regulators), and organic chemicals of increasing concern in drinking water and water re-use is well-documented. The primary drawbacks of conventional UV light sources, however is their poor form factor and environmental concerns associated with their disposal (because of the use of mercury). Microplasmas are mercury-free, non-equilibrium, low temperature plasma sources and they are characterized by high power loading (several hundreds of 100 kW/cm3) which enables them to excite gases and produce UV- generating excimer molecules efficiently. In addition to their compact (and flat!) form factor, they have other desirable attributes such as instant on-and-off, full dimmability, and low-sensitivity to the ambient temperature, all of which enable them to be efficient in various field applications when compared to their mercury-containing counterparts. In the Phase II program, we have successfully demonstrated flat UV lamps that are scalable (up to 12 12 square inches in surface area at present), flat, and have a slim form factor (total thickness less than ~ 6 mm). Thanks to enhancement of the electric field strength in arrays of microcavities fabricated within the lamp, our lamps reliably produce radiant intensities above 110 mW/cm2, which is the highest value among commercially available lamps at 172 nm. Furthermore, the spatial uniformity of light emission across the lamp is extraordinary (> 90 %). These lamps are currently being evaluated by a number of partners and customers. In parallel with our commercialization efforts, we propose to extend the UV lamp technology to the UVC wavelength range (207, 222 nm and 260 nm, in particular) which currently has the market share in UV industrial and applications. We have already validated the technical feasibility and potential markets for these flat lamps, and it is our intention to develop products and a large-volume manufacturing process to accelerate entry into the marketplace. Ultraviolet light tiles capable of producing tens of mW/cm2 at 207, 222 and 260 nm from various gas emitters and phosphors will be developed, and a product with an active area of 1 square foot at these wavelengths will be commercialized for water treatment and other commercial UV applications (disinfection of surfaces, polymer curing, etc).