Mechanical switching of ferroelectric rubber

Abstract

At the A to C transition, smectic elastomers have recently been observed to undergo approximately 35% spontaneous shear strains. We first explicitly describe how strains of up to twice this value could be mechanically or electrically induced in Sm-C elastomers by rotation of the director on a cone around the layer normal with an elastic cost dependent on constraints. Second, for typical sample geometries, we give the various microstructures in Sm-C akin to those seen in nematic elastomers under distortions with constraints. It is possible to give explicit results for the nature of the textures. Chiral Sm-C elastomers are ferroelectric. We calculate how the polarization could be mechanically reversed by large, hard, or soft strains of the rubber depending upon sample geometry.