Vertically aligned monodomain nematic liquid-crystal elastomers contract when heated. If a temperature gradient is applied across the width of such a cantilever, inhomogeneous strain distribution leads to bending motion. We modelled the kinetics of thermally induced bending in the limit of a long thin strip and the predicted time variation of curvature agreed quantitatively with experimental data from samples with a range of critical indices and nematic-isotropic transition temperatures. We also deduced a value for the thermal diffusion coefficient of the elastomer.
78.20.Hp Piezo-, elasto-, and acoustooptical effects; photoacoustic effects61.41.+e Polymers, elastomers, and plastics82.35.Ej Nonlinear optics with polymers83.80.Va Elastomeric polymers