Researchers create ‘Supercool’ Material that glows when touched

A material has been identified that crystallizes and produces light as soon as it is touched.

It has been named as an organic supercooled liquid. A video has captured the moment the material becomes extremely bright after being rubbed by a crystal. The results may prove useful in creating better memory storage systems for computers or medical sensors.

American Chemical Society has reported the research, carried out by Kyeongwoon Chung and Dr Jinsang Kim from the University of Michigan.

Researchers studied a chemical called DPP (diketopyrrolopyrrole), which has been commonly used in dyes and organic electronics applications.

The organic molecules of DPP are widely used in electronic devices such as solar cells, LEDs and transistors.

By tinkering with the ‘side chains’ of the molecules, specially the parts keeping them attached together, researchers found that they change how they behaved below their freezing point.

This meant that they can make the molecules remain liquid when cooled below their melting temperature of 134°C (273°F). Generally, this would also be the material's freezing point, but the molecules stayed in a stable, ‘supercooled’ liquid state down to 5°C (41°F), the point where the molecules solidify into a glass.

Besides the unusually broad temperature range for the supercooled liquid state, the group also found that it crystallized when rubbed with a stylus, and changed from dark red to bright yellow when put under a UV light.

The rubbing led to the breakdown of the balance in the side chains of the molecules, and allowed them to link up and produce the effect.

Dr Kim told MailOnline, “The glowing phenomenon is so-called photo luminescence. High energy photons are absorbed to the molecule and pump ground state electrons to the excited states”.

Dr Kim added that when the excited electrons come back to the ground state then the excess energy appears as light emission and the color is determined by the band gap of the molecule. Normally, you can’t see the emission under ambient light.