TY  - JOUR
A1  - Di Florio, G.
A1  - Bruendermann, E.
A1  - Yadavalli, Nataraja Sekhar
A1  - Santer, Svetlana
A1  - Havenith, Martina
T1  - Graphene multilayer as nanosized optical strain gauge for polymer surface relief gratings
JF  - Nano letters : a journal dedicated to nanoscience and nanotechnology
N2  - In this paper, we show how graphene can be utilized as a nanoscopic probe in order to characterize local opto-mechanical forces generated within photosensitive azobenzene containing polymer films. Upon irradiation with light interference patterns, photosensitive films deform according to the spatial intensity variation, leading to the formation of periodic topographies such as surface relief gratings (SRG). The mechanical driving forces inscribing a pattern into the films are supposedly fairly large, because the deformation takes place without photofluidization; the polymer is in a glassy state throughout. However, until now there has been no attempt to characterize these forces by any means. The challenge here is that the forces vary locally on a nanometer scale. Here, we propose to use Raman analysis of the stretching of the graphene layer adsorbed on top of polymer film under deformation in order to probe the strength of the material transport spatially resolved. With the well-known mechanical properties of graphene, we can obtain lower bounds on the forces acting within the film. Upon the basis of our experimental results, we can deduce that the internal pressure in the film due to grating formation can exceed 1 GPa. The graphene-based nanoscopic gauge opens new possibilities to characterize opto-mechanical forces generated within photosensitive polymer films.
KW  - Surface relief grating
KW  - optomechanical forces
KW  - photosensitive polymer films
KW  - multilayer graphene deformation
KW  - confocal Raman microscopy
Y1  - 2014
U6  - https://doi.org/10.1021/nl502631s
SN  - 1530-6984
SN  - 1530-6992
VL  - 14
IS  - 10
SP  - 5754
EP  - 5760
PB  - American Chemical Society
CY  - Washington
ER  -