Figure 1
From: Facile strain analysis of largely bending films by a surface-labelled grating method
Surface labelling of azobenzene-containing liquid-crystalline elastomer films.
(a), A homogeneously aligned azobenzene-containing liquid-crystalline elastomer film is irradiated through a grating mask, causing the photoisomerization-induced periodic change in molecular alignment to show up as a phase grating, a surface-labelled grating (due to the high absorbance of the azobenzene moieties, the grating only forms on the surface layer of the film). (b), Two subsequent exposures with mutually perpendicular grating mask orientations give rise to a two-dimensional surface-labelled grating. (c), A polarized optical micrograph of a two-dimensional surface-labelled grating. (d), The surface-labelled gratings can be used as a surface-specific strain evaluation tool for the films upon mechanical or photochemical bending, by monitoring the changes in the diffraction angle (α) of a probe laser beam. D and l represent distance between transmitted and first diffracted beams on the screen and distance between the film and the screen, respectively.
