Striping of nematic elastomers

We consider a recent experiment of Kundler and Finkelmann (Macromol. Rapid Commun. 16 (1995) 679), who subjected an aligned specimen of nematic elastomer to uniaxial extension and observed the formation of striped domains. In so doing, we apply the general theory for nematic elastomers developed by Anderson et al. (J. Elast. 56 (1999) 33) and work with an energy density that combines the effects included in the molecular-statistical theory of nematic rubber elasticity with the Oseen–Z€ocher–Frank theory of nematic curvature elasticity. Assuming that the deformation and orientation fields remain in-plane, we arrive at a boundary-value problem which admits solutions corresponding to striped states. We use elementary aspects of bifurcation theory to explore the local stability of these solutions. We also obtain analytical estimates for the energy and thickness of interstripe domain walls as functions of imposed extension and compare these with numerical predictions