Executive Summary : | Twist-Bend nematic (NTB) is a new class of nematic liquid crystal (LC) that was theoretically predicted in bent core molecules by Dozov and experimentally reported by Cestari et al in 2011. The NTB phase is formed by long bent molecules spontaneously self-assembling in a heli-conical structure of nanoscale periodicity. Researchers have been studying the physical principles behind the stability of this phase and its signatures. Two important features of the NTB phase are the decrease in the bend elastic constant (K33) and the additional contribution to total flexoelectric polarization due to the coupling between the director n and helical axis direction t. To investigate the electric field effects in a NTB phase, researchers propose methods such as applying an electric field parallel to the helical axis direction, systematically measuring K33 close to the N-NTB phase transition temperature, and measuring the effective flexo-coefficient using an electro-optical method in an in-plane field cell. |