Low-cost, light-emitting inks that can be painted onto surfaces could be a boon for large electronic displays. Researchers have come up with a method of producing glowing ink that avoids the use of solvents, which typically must be evaporated away after the ink is 'printed'. This evaporation can change the ink's colour.

Credit: WILEY-VCH VERLAG

Takashi Nakanishi at the National Institute for Materials Science in Tsukuba, Japan, and his colleagues synthesized small organic molecules that form luminescent liquids at room temperature. These were mixed with other dyes to form a stable paste that glows in shades of white when illuminated with ultraviolet radiation, as illustrated by a light-emitting diode (pictured, left) painted with the paste (right).

The new paste produces an impractical sticky film, but the researchers say they are working to solve the problem.

Angew. Chem. Int. Ed. 51, 3391–3395 (2012)