New displays from magnetically responsive liquid crystals

According to the university, the research paves the way for novel display applications relying on the instantaneous and contactless nature of magnetic manipulation-such as signage, posters, writing tablets, and billboards. Study results appear online in Nano Letters.

Commercially available liquid crystals, used in modern electronic displays, are composed of rod-like or plate-like molecules. When an electric field is applied, the molecules rotate and align themselves along the field direction, resulting in a rapid tuning of transmitted light.

‘The liquid crystals we developed are essentially a liquid dispersion, a simple aqueous dispersion of magnetic nanorods,’ said Yadong Yin, an associate professor of chemistry, who led the research project. ‘We use magnetic nanorods in place of the commercial non-magnetic rod-like molecules. Optically these magnetic rods work in a similar way to commercial rod-like molecules, with the added advantage of being able to respond rapidly to external magnetic fields.’

Yin said that upon the application of a magnetic field, the nanorods spontaneously rotate and realign themselves parallel to the field direction, and influence the transmittance of polarised light.