I am looking for other photosensitive materials that change state, but produce significant physical distortion.
Silver halide crystals, for example, has a photographic-and unique photochemical qualities, but no significant change in physical presentation.
However, Azobenzene is noted as being a material that undergoes photo-isomerization due to light, producing molecular level unfolding or motion. The witnessed isomerization has also been demonstrated at a bulk or meso-scopic scale to lead to larger length motion on scales of inches through the folding and unfolding of origami like structures. A thin film of azobenzene was made to bend and unbend by exposing it to polarized light. The direction of the macroscopic motion could be controlled by the polarization direction, or wavelength. The bending occurred because the free surface of the material contracted more than the inside of the thin film (due to absorption of laser light as it passes through the film).
I am interested if there are other unique photo-mechanical compounds (or chemical-photon interaction processes) that exhibit similar or increased bulk strain behaviors.