Photomechanical energy conversion based on cross-linked liquid-crystalline polymers

An actuator is an energy transducer that can convert input energies into work. Cross-linked liquid-crystalline polymers show photoinduced deformation with changes in the molecular shape and alignment of the polymers. Polymer materials can transduce converted light energy into mechanical stress by the macroscopic deformation of the polymers (photomechanical effect). The effect of the molecular structures of the photochromic liquid-crystalline polymers on the photoinduced deformation is studied. The mechanism of the photoinduced deformation of the polymers is investigated. Three-dimensional movements of the liquid-crystalline polymers are achieved by laminating the polymers into a flexible polymer sheet. In this review, the design of the polymer materials with a photochromic moiety and an evaluation of their photomechanical effects are described. The photomodulation of the alignment of liquid-crystalline polymers and their applications for light-driven polymer actuators are summarized. Polymer Journal (2013) 45, 239-246; doi:10.1038/pj.2012.140; published online 1 August 2012