TY  - JOUR
A1  - Jelken, Joachim
A1  - Santer, Svetlana
T1  - Light induced reversible structuring of photosensitive polymer films
JF  - RSC Advances
N2  - In this paper we report on photoswitchable polymer surfaces with dynamically and reversibly fluctuating topographies. It is well known that when azobenzene containing polymer films are irradiated with optical interference patterns the film topography changes to form a surface relief grating. In the simplest case, the film shape mimics the intensity distribution and deforms into a wave like, sinusoidal manner with amplitude that may be as large as the film thickness. This process takes place in the glassy state without photo-induced softening. Here we report on an intriguing discovery regarding the formation of reliefs under special illumination conditions. We have developed a novel setup combining the optical part for creating interference patterns, an AFM for in situ acquisition of topography changes and diffraction efficiency signal measurements. In this way we demonstrate that these gratings can be “set in motion” like water waves or dunes in the desert. We achieve this by applying repetitive polarization changes to the incoming interference pattern. Such light responsive surfaces represent the prerequisite for providing practical applications ranging from conveyer or transport systems for adsorbed liquid objects and colloidal particles to generation of adaptive and dynamic optical devices.
KW  - surface-relief gratings
KW  - induced deformation
KW  - mass-transport
KW  - azobenzene elastomers
KW  - thin-films
KW  - birefringence
KW  - roughness
KW  - network
KW  - erasure
Y1  - 2019
U6  - https://doi.org/10.1039/C9RA02571E
SN  - 2046-2069
VL  - 9
IS  - 35
SP  - 20295
EP  - 20305
PB  - RSC Publishing
CY  - London
ER  - 
TY  - GEN
A1  - Jelken, Joachim
A1  - Santer, Svetlana
T1  - Light induced reversible structuring of photosensitive polymer films
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - In this paper we report on photoswitchable polymer surfaces with dynamically and reversibly fluctuating topographies. It is well known that when azobenzene containing polymer films are irradiated with optical interference patterns the film topography changes to form a surface relief grating. In the simplest case, the film shape mimics the intensity distribution and deforms into a wave like, sinusoidal manner with amplitude that may be as large as the film thickness. This process takes place in the glassy state without photo-induced softening. Here we report on an intriguing discovery regarding the formation of reliefs under special illumination conditions. We have developed a novel setup combining the optical part for creating interference patterns, an AFM for in situ acquisition of topography changes and diffraction efficiency signal measurements. In this way we demonstrate that these gratings can be “set in motion” like water waves or dunes in the desert. We achieve this by applying repetitive polarization changes to the incoming interference pattern. Such light responsive surfaces represent the prerequisite for providing practical applications ranging from conveyer or transport systems for adsorbed liquid objects and colloidal particles to generation of adaptive and dynamic optical devices.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 750 
KW  - surface-relief gratings
KW  - induced deformation
KW  - mass-transport
KW  - azobenzene elastomers
KW  - thin-films
KW  - birefringence
KW  - roughness
KW  - network
KW  - erasure
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436432
SN  - 1866-8372
IS  - 750
SP  - 20295
EP  - 20305
ER  - 
TY  - GEN
A1  - Di Florio, Giuseppe
A1  - Bründermann, Erik
A1  - Yadavalli, Nataraja Sekhar
A1  - Santer, Svetlana
A1  - Havenith, Martina
T1  - Polarized 3D Raman and nanoscale near-field optical microscopy of optically inscribed surface relief gratings
BT  - chromophore orientation in azo-doped polymer films
N2  - We have used polarized confocal Raman microspectroscopy and scanning near-field optical microscopy with a resolution of 60 nm to characterize photoinscribed grating structures of azobenzene doped polymer films on a glass support. Polarized Raman microscopy allowed determining the reorientation of the chromophores as a function of the grating phase and penetration depth of the inscribing laser in three dimensions. We found periodic patterns, which are not restricted to the surface alone, but appear also well below the surface in the bulk of the material. Near-field optical microscopy with nanoscale resolution revealed lateral two-dimensional optical contrast, which is not observable by atomic force and Raman microscopy.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 247 
KW  - glass-transition temperature
KW  - holographic diffraction gratings
KW  - chain azobenzene polymers
KW  - molecular-reorientation
KW  - amorphous polymers
KW  - data-storage
KW  - thin-films
KW  - dye
KW  - photoisomerization
KW  - alignment
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95233
SP  - 1544
EP  - 1554
ER  -