Fabrication of Photoactuators: Macroscopic Photomechanical Responses of Metal-Organic Frameworks to Irradiation by UV Light

Photoreactive olefinic species are incorporated into a metal- organic framework ( MOF), [ Zn( bdc)( 3- F- spy)] ( 1). Single crystals of 1 are shown to undergo three types of photomechanical macroscopic deformation upon illumination by UV light. To demonstrate the practical potential of this system, the inclusion of 1 in a PVA ( polyvinyl alcohol) composite membrane, by exploiting hydrogen- bonding interactions, is presented. Using this composite membrane, the amplification of mechanical stress to achieve macroscopic actuation behavior is demonstrated. These results pave the way for the generation of MOF- based soft photoactuators that produce clearly defined mechanical responses upon irradiation with light. Such systems are anticipated to have considerable potential in photomechanical energy harvesting and conversion systems.