Elastic parameters of smectic C ∗ liquid crystals

Numerical simulations of the electro-optic properties of smectic C ∗ liquid crystal layers can be helpful in the research into and development of displays. A major problem is that the number of elastic parameters that is open to experimental determination is less than the number of parameters that occurs in the elasticity theory for the smectic C ∗ phase. Two elastic parameters contained in a simplified expression for the deformation energy are experimentally determined for the smectic C ∗ material ZLI 3654 (Merck, Germany). The accuracy of the measured results is discussed.