@phdthesis{Mechau2005,
  author    = {Mechau, Norman},
  title     = {Lichtinduziertes Erweichen azobenzolhaltiger Polymerfilme},
  address   = {Potsdam},
  pages     = {156 S. : graph. Darst.},
  year      = {2005},
  language  = {de}
}
@article{MechauSaphiannikovaNeher2005,
  author    = {Mechau, Norman and Saphiannikova, Marina and Neher, Dieter},
  title     = {Dielectric and mechanical properties of azobenzene polymer layers under visible and ultraviolet irradiation},
  issn      = {0024-9297},
  year      = {2005},
  abstract  = {Photoinduced changes in the mechanical and dielectric properties of azobenzene polymer films were measured utilizing the method of electromechanical spectroscopy. The measurements revealed a strong correlation between the time- dependent behavior of the plate compliance and the dielectric constant under irradiation. Actinic light causes a light softening of the film that also manifests itself in the increase of the dielectric constant, whereas ultraviolet irradiation results in an initial plasticization of the film followed by its hardening. The latter is accompanied by decrease of the dielectric constant. A semiquantitative model based on the kinetics of the photoisomerization process in azobenzene polymers is proposed. We assume that both visible and ultraviolet irradiation increase the free volume in the layer due to photoisomerization. Additionally, ultraviolet light increases the modulus of the polymer matrix due to the presence of a high density of azobenzene moieties in the cis state. These assumptions allowed us to reproduce the time- dependent behavior of the bulk compliance as well as the dielectric constant at different irradiation intensities, for both visible and ultraviolet light, with only two adjustable parameters},
  language  = {en}
}
@article{MechauSaphiannikovaNeher2006,
  author    = {Mechau, Norman and Saphiannikova, Marina and Neher, Dieter},
  title     = {Molecular tracer diffusion in thin azobenzene polymer layers},
  series = {Applied physics letters},
  volume    = {89},
  journal   = {Applied physics letters},
  number    = {25},
  publisher = {Elsevier},
  address   = {Melville},
  issn      = {0003-6951},
  doi       = {10.1063/1.2405853},
  pages     = {3},
  year      = {2006},
  abstract  = {Translational diffusion of fluorescent tracer molecules in azobenzene polymer layers is studied at different temperatures and under illumination using the method of fluorescence recovery after photobleaching. Diffusion is clearly observed in the dark above the glass transition temperature, while homogeneous illumination at 488 nm and 100 mW/cm(2) does not cause any detectable diffusion of the dye molecules within azobenzene layers. This implies that the viscosity of azobenzene layers remains nearly unchanged under illumination with visible light in the absence of internal or external forces. (c) 2006 American Institute of Physics.},
  language  = {en}
}
@article{StillerKarageorgievGeueetal.2004,
  author    = {Stiller, Burkhard and Karageorgiev, Peter and Geue, Thomas and Morawetz, Knut and Saphiannikova, Marina and Mechau, Norman and Neher, Dieter},
  title     = {Optically induced mass transport studied by scanning near-field optical- and atomic force microscopy},
  issn      = {0204-3467},
  year      = {2004},
  abstract  = {Some functionalised thin organic films show a very unusual property, namely the light induced material transport. This effect enables to generate three-dimensional structures on surfaces of azobenzene containing films only caused by special optical excitation. The physical mechanisms underlying this phenomenon have not yet been fully understood, and in addition, the dimensions of structures created in that way are macroscopic because of the optical techniques and the wavelength of the used light. In order to gain deeper insight into the physical fundamentals of this phenomenon and to open possibilities for applications it is necessary to create and study structures not only in a macroscopic but also in nanometer range. We first report about experiments to generate optically induced nano structures even down to 100 nm size. The optical stimulation was therefore made by a Scanning Near-field Optical Microscope (SNOM). Secondly, physical conditions inside optically generated surface relief gratings were studied by measuring mechanical properties with high lateral resolution via pulse force mode and force distance curves of an AFM},
  language  = {en}
}