Optical proximity and touch sensors based on monolithically integrated polymer photodiodes and polymer LEDs

An optical touch and proximity sensor based on polymer light-emitting diodes and polymer photodiodes is presented. The sensor’s thin-film light sources and detectors are monolithically integrated in the same plane of a common substrate and are processed from the liquid phase at room-temperature. These key features make the sensor potentially attractive for applications where low cost, small device thickness, tight space requirements or mechanical flexibility matter, such as simple information displays with touch switch functionality, for example. A static light-emitting sign with integrated touch switch is demonstrated here.