Dainippon Licenses Research Frontiers Technology for "Smart" Windows
Research Frontiers Inc. (Woodbury, NY) has granted a non-exclusive license to Japan-based Dainippon Ink and Chemicals Inc., permitting that company to manufacture and sell to authorized licensees emulsions used to manufacture light-controlling film developed by Research Frontiers and its licensees. The suspended particle device (SPD) technology enables users to electrically and precisely control the passage of light through windows, sunroofs, sunvisors, mirrors and eyewear, as well as enabling brighter easier to read flat panel displays for computers and other products. SPD film can be controlled either automatically by means of a photocell or other sensing or control device, or adjusted manually by the user.
The emulsions comprise liquid matrix polymers combined with liquid suspensions of light-absorbing particles developed by Research Frontiers. When cured, or crosslinked, by ultraviolet radiation, a layer of emulsion becomes a solid film within which millions of extremely small droplets of liquid suspension comprising the particles are distributed.
The solid film, sometimes referred to as the "activatible material" is generally laminated in between sheets of plastic or glass which have transparent, electrically conductive coatings on their inner surfaces in contact with the film. A source of low-current AC voltage connected to the coatings aligns the particles within the droplets, enabling the film to become clear; without voltage, the film is dark.
The off-state color of the film is determined by the type of particles present in the droplets. At present, the off-state color of SPD films is dark blue. In the future, however, additional colors such as black or grey may become available if Research Frontiers or DIC develops new types of particles which are substituted for the current particles. As a producer of organic pigments, DIC is in an especially good position to develop such particles and to thereby greatly expand the potential markets for SPD films and products.