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Journal of Nanomaterials
Volume 2015 (2015), Article ID 840182, 7 pages
http://dx.doi.org/10.1155/2015/840182
Research Article

Liquid Crystal Microlens Using Nanoparticle-Induced Vertical Alignment

1Department of Electro-Optics Engineering and Optoelectronics Research Laboratory, National United University, Miaoli 36063, Taiwan
2BenQ Materials Corporation, Taoyuan 33341, Taiwan
3Dongzauto Co., Ltd., Yilan 26950, Taiwan

Received 18 September 2014; Revised 18 December 2014; Accepted 19 December 2014

Academic Editor: J. David Carey

Copyright © 2015 Shug-June Hwang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The nanoparticle-induced vertical alignment (NIVA) of the nematic liquid crystals (LC) is applied to achieve an adaptive flat LC microlens with hybrid-aligned nematic (HAN) mode by dropping polyhedral oligomeric silsesquioxane (POSS) nanoparticle solution on a homogeneous alignment layer. The vertical alignment induced by the POSS nanoparticles resulted in the formation of a hybrid-aligned LC layer with concentric nonuniform distribution of the refractive index in the planar LC cell, which subsequently played the role of the lens, even in the absence of any applied voltages. The dimensions of the concentric HAN structure significantly depend on the volume of the microdroplet and the POSS concentration. The focus effect of this flat microlens was observed while electrically controlling its focal length using the applied voltages from −50 mm to −90 mm.