Luminescent line art by direct-write patterning

We present a direct-write patterning method for the realization of electroluminescent (EL) line art using a surface-emissive light-emitting electrochemical cell with its electrolyte and EL material separated into a bilayer structure. The line-art emission is achieved through subtractive patterning of the electrolyte layer with a stylus, and the single-step patterning can be either manual for personalization and uniqueness or automated for high throughput and repeatability. We demonstrate that the light emission is effectuated by cation-assisted electron injection in the patterned regions and that the resulting emissive lines can be as narrow as a few micrometers. The versatility of the method is demonstrated through the attainment of a wide range of light-emission patterns and colors using a variety of different materials. We propose that this low-voltage-driven and easy-to-modify luminescent line-art technology could be of interest for emerging applications, such as active packaging and personalized gadgets. Organic photonics: luminescent line art Decorative light-emitting patterns look set to give packaging and gadgets a striking new appearance. The luminescent line art, developed by scientists in Sweden and Australia, is made by patterning the electrolyte layer of a bilayer light-emitting electrochemical cell with the desired artwork design. The pattern is ‘drawn’ by a mechanical stylus into the electrolyte layer. The patterning allows holes and electrons to recombine in the electroluminescent layer of the cell, and hence visible light is emitted when the cell is driven by an electrical signal of just a few volts. The developers say that the approach suits high-volume manufacturing and that the resulting line art can have a spatial resolution as fine as a few micrometres. The emission colour can be controlled by changing the electroluminescent compound employed in the cell.