Modeling Helicoid to Spiral-Ribbon Transitions of Twist-Nematic Elastomers

Nematic Elastomers (NEs) possess very interesting properties stemming from the interaction between liquid crystal order and rubber elasticity. For such materials, thermally induced phase transition from the isotropic to the nematic phase may induce very large distortions, which in turn can affect the overall configuration of a macroscopic specimen. The behavior of NEs can be well modeled within the theory of finite elasticity with distortions; here, we test a theoretical model against fancy shapes formation; in particular, we deal with the many different shapes that a thin, slender bar, made of NE, may assume as a consequence of its chiral symmetry during solvent evaporation and subsequent heating. Our goal has been to replicate with numerical experiments the phenomena of shape formation in chiral NEs, and our results constitute a noteworthy assessment of the physical model underlying the numerical solutions.