Rapid and Reversible Shape Changes of Molecular Crystals on Photoirradiation

Seiya Kobatake, Shizuka Takami, Hiroaki Muto, Tomoyuki Ishikawa and
Masahiro Irie

　　Although in biological systems molecular-scale shape changes of proteins are successfully linked to macro-scale motion of muscles, man-made molecular devices fail to link the shape changes of molecules to large scale motion of materials. Here we report that molecular crystals based on photochromic diarylethene chromophores and with size ranging from 10 to 100 micro meters exhibit rapid and reversible macroscopic changes in shape and size induced by ultraviolet and visible light. The crystals can move macroscopic objects, making them promising materials for possible light-driven actuator applications.