Aug 3 2010
Scientists at the Laboratory for Laser Energetics, University of Rochester, have developed a new membrane that stops gas from passing through it when an ultraviolet light illuminates the surface, and allows the gas to pass when a purple light is utilized.
Kenneth Marshall and Eric Glowacki invented the innovative membrane. The findings will be presented at the International Society for Optics and Photonics in San Diego.
The membrane is made of hard plastic punched with small holes. The holes are filled with a dye and liquid crystals. When an ultraviolet light is used to illuminate the membrane’s surface, the molecules present in the dye turn into a banana-shape and the liquid crystals disperse randomly, obstructing the tunnel and stopping the gas from passing through. When a purple light is used to light the surface, the molecules get straightened out and allow the liquid crystals to fall in line, enabling the gas to pass via the holes.
Eric Glowacki informed that controlling the permeability of the membrane with light is better than controlling it with electricity and heat. A major advantage of using light is that it cannot ignite gas, which could prove useful for individuals working with flammable gases. Another benefit is that the color of the light used for lighting the membrane can be altered instantly and accurately. Moreover, a laser or lamp can be shined at the membrane from a distance. This will enable engineers to design compact and simpler models.
The membrane could prove useful in industrial process applications, research applications and controlled drug delivery.