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Electrical and Computer Engineering

Technological University Dublin

2010

Liquid Crystal

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Electric Field Induced Biaxiality And The Electro-Optic Effect In A Bent-Core Nematic Liquid Crystal, Mamatha Nagaraj, Yuri Panarin, U. Manna, J. K. Vij, C. Keith, C. Tschierske Jan 2010

Electric Field Induced Biaxiality And The Electro-Optic Effect In A Bent-Core Nematic Liquid Crystal, Mamatha Nagaraj, Yuri Panarin, U. Manna, J. K. Vij, C. Keith, C. Tschierske

Articles

We report the observation of a biaxial nematic phase in a bent-core molecular system using polarizing microscopy, electro-optics, and dielectric spectroscopy, where we find that the biaxiality exists on a microscopic scale. An application of electric field induces a macroscopic biaxiality and in consequence gives rise to electro-optic switching. This electro-optic effect shows significant potential in applications for displays due to its fast high-contrast response. The observed electro-optic switching is explained in terms of the interaction of the ferroelectric clusters with the electric field. © 2010 American Institute of Physics.


Liquid Crystal Display Modes In A Nontilted Bent-Core Biaxial Smectic Liquid Crystal, Mamatha Nagaraj, Yuri Panarin, J. K. Vij, C. Keith, C. Tschierske Jan 2010

Liquid Crystal Display Modes In A Nontilted Bent-Core Biaxial Smectic Liquid Crystal, Mamatha Nagaraj, Yuri Panarin, J. K. Vij, C. Keith, C. Tschierske

Articles

Liquid crystal display (LCD) modes associated with the rotation of the secondary director in nontilted, biaxial smectic phase of an achiral bent-core compound are demonstrated. For LCDs, we find that at least four display modes are possible using SmAPA phase of the studied material, in which the minor directors in adjacent layers are aligned antiferroelectrically. The advantages of these modes include low driving field (1–2 V/ µm), high contrast ratio 1000:1, relatively fast switching time of 0.5 ms and continuous gray scale. The molecular short axis or the polar axis in a negative dielectric, biaxial material is oriented by the …