NIR-light-induced deformation of cross-linked liquid-crystal polymers using upconversion nanophosphors

J Am Chem Soc. 2011 Oct 12;133(40):15810-3. doi: 10.1021/ja2043276. Epub 2011 Sep 19.

Abstract

When upconversion nanophosphors were incorporated into an azotolane-containing cross-linked liquid-crystal polymer film, the resulting composite film generated fast bending upon exposure to continuous-wave near-IR light at 980 nm. This occurs because the upconversion luminescence of the nanophosphors leads to trans-cis photoisomerization of the azotolane units and an alignment change of the mesogens. The bent film completely reverted to the initial flat state after the light source was removed.