A new torsion pendulum technique to measure the twist elastic constant of liquid crystals

Abstract
A new experimental method to measure the twist elastic constant of nematic liquid crystals is proposed. The method is based on a direct measurement of the torque which the nematic liquid crystal exerts on the surfaces when a magnetic field is applied. The reliability of this technique is tested by measuring the twist elastic constant of the nematic liquid crystal 4-n-pentyl-4'-cyanobiphenyl (5CB). The experimental results are compared with previous measurements performed by other authors