Synthesis of a photoresponsive liquid-crystalline polymer containing azobenzene

The synthesis of an oriented liquid-crystalline photoresponsive polymer, prepared by polymerization of mono- and di-acrylates, both of which contain azobenzene chromophores, is reported. The prepared free-standing polymer film shows strong reversible photoinduced deformation upon exposure to unpolarized UV light at 366 nm, as a result of an optically induced isomeric change of the azobenzene moieties in the polymer network. The synthesis process is relatively simple and more efficient compared to conventional ones, and can be used to synthesize other liquid-crystalline photoresponsive polymers. The use of this photoresponsive polymer film as an optical high-pass/low-pass switch under UV or natural light irradiation for a laser beam is demonstrated. This photoresponsive polymer may have applications in robotic systems, artificial muscles, and actuators in microelectromechanical systems (MEMS) and labs on chips.