Electrical Actuation of Cholesteric Liquid Crystal Gels.

We demonstrate that the cholesteric liquid crystal (CLC) gels with a global helical variation in their orientation exhibit the pronounced electro-optical and electromechanical effects under an unconstrained geometry. A sufficiently high electric field imposed along the helical axis drives a finite elongation exceeding 30% along the field axis, as well as a finite redshift of the selective reflection band which is opposite to the blueshift often observed for the conventional CLCs and the in situ polymer stabilized CLCs under an electric field.