Nanoscopic actuators in light-induced deformation of glassy azo-polymers

We present the theoretical and computer simulation studies of photo-mechanics in glassy azo-oligomers. Angular distributions of chromophores in respect to the backbones obtained at different temperatures served as input into a theoretical expression for the striction stress, which was found to be positive for the structure under investigation. The light-induced reorientation of typical propeller-like structures is shown to be a microscopic reason of the sample elongation. The azo-propellers work as nanoscopic actuators which convert the light energy into material deformation. This finding opens a way for prediction of photomechanical properties of glassy azo-compounds directly from their chemical structure.