Hui-Lung Kuo

Nanoimprinting-lithography-induced self-aligned liquid crystals for novel multifunctional optical films

Polymerizable nematic liquid crystal (LC) was adopted as a resist for our newly developed nanoimprinting lithography process. Liquid crystal molecules were self-aligned during imprinting process without precoated alignment layer. The large patterned area was able to achieve 4×4cm2 at very low impriting pressure, 1.5bar. The optical anisotropic was verified through polarized optical microscopy and the retardation was measured by polarized ultraviolet/visible spectrometer. The micrograted LC films prepared by this novel method offer the potential applications for a LC alignment layer within LC cells, as well as preparation of optical anisotropic films.

Optical detection of organic vapors using cholesteric liquid crystals

The two organic vapors are acetone and toluene, which are identified using the colorimetry of cholesteric liquid crystals. The helical structure of cholesteric liquid crystal is diffused by organic vapor molecules, and the reflection spectrum of the cholesteric liquid crystal is red-shifted. The reflection spectra of the cholesteric liquid crystal reveal that the rates of variation of reflected color with the absorption of acetone and toluene vapors are different markedly because of the diversity of molecular polarities in the different molecular polarities of acetone and toluene vapors. A higher molecular polarity of the vapor causes a greater shift in the reflected color of cholesteric liquid crystal.

Cholesteric liquid crystal-carbon nanotube hybrid architectures for gas detection

The ability of a hybrid material that is based on cholesteric liquid crystal and carbon nanotube to detect acetone vapor is investigated. We find that the phase transition in this cholesteric liquid crystal-carbon nanotube hybrid will enable carbon nanotube to form conducting networks under the higher vapor concentration. This cholesteric liquid crystal-carbon nanotube hybrid exhibits an obvious change in reflected color and electrical resistance in the early and later stages of gas diffusion, respectively. This hybrid architecture has potential application as a gas sensor with a high dynamic range.

P‐122: A Novel Wire Grid Polarizer

A new wire grid polarizer is made through a series of nanofabrication steps. The visible light polarization effect will occur when natural incident light interact with the novel double layers metal nano-grating structure on the surface of said polarizer. It gives very high extinction ratio and also no angular dependency. Theoretically, even the incident angle is over 75°, it still possible to give polarization extinction ratio over 5000:1. The feature sizes of the nano-grating structures have major influence to the polarization states of the reflective and transmitting light. The materials compose the nano grating structure and the morphology also affects the polarization effect. A 5mm × 5mm sample was made and the results will present in this paper.

27.4: Nanoimprinting Lithography as Novel Tool Inducing Self-Aligned Liquid Crystals For Alignment Layer

Polymerizable nematic liquid crystal (LC) was applied as resist for our newly developed nanoimprinting lithography process. The LC resist was self-aligned during imprinting process at very low impriting pressure, 1.5 bar and the patterned area was able to achieve 4×4 cm2. The optical anisotropic was verified through polarized optical microscopy (POM). The various thickness of LC resist was evaluated and compared alignment ability with polyimide, and isotropic resists. The micro-grated LC films prepared by this novel method offer new applications for liquid crystal as alignment layer within LC cells as well as preparation of optical anisotropic films.