Electro-mechanical coupling in nematic elastomers: statics and dynamics

SUMMARY. New analytical and computational results on the static and dynamic response of ne-matic elastomers to applied electric fields and mechanical loads are reviewed, and compared with the available experimental evidence. 1 INTRODUCTION Nematic elastomers display a peculiar mechanical response arising from the interplay between the electro-optical properties of liquid crystals and the elastic properties of a rubbery solid. They have been the subject of numerous studies in the recent literature, see [21] and the many references cited therein. Envisaged by the late P.G. de Gennes [5], nematic elastomers were synthesized at the end of the 80s [22], [15]. Early experiments [16], [17] have immediately shown their potential as materials for soft actuators (large spontaneous deformations which, as it is now known, can be activated thermally, by electric fields, or UV light). At the same time, these experiments have revealed a very rich and complex behavior: unusually soft elastic response to uniaxial stretching, akin to the phenomenon of super-elasticity in shape memory alloys, and stripe domain instabilities, which are reminiscent of mechanical twinning. The interest in the theoretical understanding of the behavior of nematic elastomers has been strong and sustained, starting from the pioneering paper of de The goal of this paper is to present some new analytical and computational results on the static and dynamic response of nematic elastomers to applied electric fields and mechanical loads. As discussed in [11], these results can be used to understand both the classical stretching experiments in [16], [17] and the more recent experimental measurements contained in [18], [19], and [12].