Research objectives and content
The flexoelectric effect in liquid crystals is similar to the piezoelectric effect in solid state and represents the coupling between an applied electric field and a material deformation. The aim of our project is to investigate flexoelectric effects in liquid crystals at a molecular level. This will be performed by combining computer simulations and density functional methods. First we shall model the interaction potential between molecules of asymmetric shape using suitable attractive-repulsive potentials of the Gay-Berne type. This model will then be used within Monte Carlo simulations of flexoelectric deformations. The simulation results will be analysed in terms of profiles of the orientational order and spatial correlations of dipole moments. Moreover, a density functional approach to flexoelectricity will be developed allowing the derivation of microscopic expressions for the flexoelectric coefficients. The latter will then be calculated from the computer simulation data and their dependence on molecular properties will be studied. This evaluation will provide significant progress in the understanding of the molecular origins of flexoelectricity.
Training content (objective, benefit and expected impact)
Considering my scientific background as a theoretical physicist, it will be an advantageous experience for me and improve my knowledge of molecular modeling to work on a project that is connected to physical chemistry. In particular, I shall strongly benefit from the ability in computer simulations of liquid crystalline materials available in Prof. Zannoni's group. Combining the high level of expertise of the group in Bologna with my former research we expect an important impact to the research on flexoelectricity.
Links with industry / industrial relevance (22)
Although this is a basic research project, an advanced understanding of the molecular origins of the flexoelectric effect should lead to improvement in the characteristics of these materials in view of potential applications in electromechanical transducers.