Azo-dye-doped liquid crystal elastomers (LCEs) are known to show a strong photomechanical response. We report on experiments that suggest that photothermal heating is the underlying mechanism in surface-constrained geometry. In particular, we use optical interferometry to probe the length change of the material and direct temperature measurements to determine heating. LCEs with various dopants and optical density were used to study the individual mechanisms. In the high dye-doped limit, most of the light is absorbed near the entry surface, which causes a local strain from photothermal heating and a nonlocal strain from thermal diffusion. The results of our research on the microscopic mechanisms of the photomechanical response can be applied to designing photomechanical materials for actuating/sensing devices, the potential basis of smart structures. (C) 2011 Optical Society of America
Journal of the Optical Society of America B-Optical Physics
This paper was published in the Journal of the Optical Society of America B and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/JOSAB.28.001916.Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
Dawson, Nathan J.; Kuzyk, Mark G.; Neal, Jeremy; Luchette, Paul; Palffy-Muhoray, Peter (2011). Experimental Studies of the Mechanisms of Photomechanical Effects in a Nematic Liquid Crystal Elastomer. Journal of the Optical Society of America B-Optical Physics 28(8) 1916-1921. doi: 10.1364/JOSAB.28.001916. Retrieved from https://oaks.kent.edu/cpippubs/361