By Andrew H. Dent
The diminished size, low-temperature usage, and easy control of color of LED lighting has led to a wide range of new applications. This technology, called LED-embedded Light Films, teams an LED with conductive polymer films, creating a thin, flexible transparent sheet with LED lights embedded into the surface. There are no visible connectors between the lights (the polymer sheet itself acts as the "wiring"), and the sheets may themselves be laminated between glass, added to molded polymers, or used as lightweight backlighting for electronics. The films are then simply connected to a power source via a wire. The largest single sheet of film currently available is made by SUN-TEC Swiss United Technologies in Hünenberg, Switzerland, and measures 4 x 11 feet (1250 mm x 3500 mm). The maximum number of LEDs is 36 per square foot. The films operate between 12 and 48 Volts DC, each LED requires 0.055 Watts, and the lifetime of the LEDs can range from 40,000 to 80,000 hours. The lights do not emit heat and may be embedded evenly or in any custom pattern, and the films can be printed on, allowing the inclusion of graphics. The sheets are currently used as laminated films in architectural glazing to create unique lighting effects, though they may also find application in consumer products.
Dr. Andrew H. Dent, PhD, is vice-president, Library & Materials Research at Material ConneXion, a leading global platform for material innovations and solutions