Micro-Cavity Arrays - Lighting the Way to the Future

A research team funded by the Air Force Office of Scientific Research has pioneered the use of micro-plasmas in a revolutionary approach to illumination, and doctors Gary Eden and Sung-Jin Park of the University of Illinois, Urbana-Champaign, have founded Eden Park Illumination, Inc. to bring this new lighting technology to the world.

Just as in a fluorescent light, a micro-cavity array (MCA) is energized by an applied voltage. By successfully confining plasma in parallel rows of micro-cavities within thin sheet materials, Eden and Park ultimately arrived at various implementations of micro-plasma arrays - some of which result in inexpensive, wafer-thin, and very flexible sheets of light.

The key to these light arrays are the micro-cavities which are formed within the flexible sheets. In one of the most important implementations, the one being developed by Eden Park Illumination, a sheet of aluminum foil is placed in an anodizing bath. By controlling the bath parameters, its temperature, and the time of anodizing, large arrays of micro-cavities can be formed with near optimum shape and with automatically placed interconnecting aluminum electrodes. The largest array thus far contains a quarter million luminous micro-cavities. Thin laminated films on the surface of the wafer contain the electrical power interconnects which feed the individual cavities. When A/C power is supplied through the almost invisible grid, the array bursts to life.

Many gases can be used to make the micro-plasma arrays. In Eden Park's commercialization processes, rare gases produce ultraviolet light, and specialty phosphors convert the UV into visible light, as in fluorescent lamps.