Is there a more detailed description of how SPD technology works?
Suspended particle devices, more commonly known as “SPDs” or “light valves,” use a film within which droplets of liquid suspension are distributed. Light-absorbing microscopic particles are dispersed within the liquid suspension. The film is then enclosed between two glass or plastic plates coated with a transparent conductive material. The particles are randomly oriented due to Brownian motion and absorb light. When an electrical voltage is applied, the particles align due to a field effect and light passes through. This gives users a range of transparency where light transmission can be rapidly varied depending upon the amount of voltage applied. Research Frontiers currently holds over 500 U.S. and foreign patents and patent applications covering light-control technology.
