Thermal diffusion and bending kinetics in nematic elastomer cantilever

TL;DR

This paper models the thermal diffusion and bending behavior of nematic elastomer cantilevers under temperature gradients, providing quantitative predictions and experimental validation of curvature dynamics.

Contribution

It introduces a kinetic model for thermally-induced bending in nematic elastomers and accurately predicts curvature evolution, including thermal diffusion effects.

Findings

Quantitative agreement between model and experiments

Estimated thermal diffusion coefficient of the elastomer

Validated kinetic model for bending dynamics

Abstract

Vertically aligned mono-domain 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.