Fast Turn-Off Switching of Vertically-Aligned Negative Liquid Crystals by Fine Patterning of Pixel Electrodes

Abstract

We investigated the two-dimensional (2D) confinement effect on the switching of vertically-aligned negative liquid crystals (LCs) by an electric field applied between the top and bottom patterned electrodes. When an electric field is applied to a patterned vertical alignment (PVA) cell, virtual walls form in the middle of the gaps between and at the center of the patterned electrodes. These virtual walls formed in a PVA cell results in the turn-off time being dependent on the pitch of the patterned electrodes as well as the cell gap. We found that a short response time can be achieved by the fine patterning of pixel electrodes with little decrease in the transmittance. The obtained numerical results agree well with the model based on the 2D confinement effect of LCs.

Fabrication of Zigzag Parylene Nanofibers in Liquid Crystals with Electric Field-Induced Defect Structures

“…After filtration and solvent removal, the product was purified on silica gel using n-hexane and ethyl acetate to yield 4-formyl[2.2]paracyclophane as white crystals (10.4 g, 91.7%). 1 H NMR (400 MHz, DMSO-d 6 , δ): 9.94 (s, 1H, CHO), 7.03 (d, J = 2.0 Hz, 1H, Ar H), 6.81 (dd, J = 7.8, 2.0 Hz, 1H, Ar H), 6.65 (d, J = 7.8 Hz, 1H, Ar H), 6.58 (dd, J = 7.9, 1.9 Hz, 1H, Ar H), 6.51 (dd, J = 7.8, 1.9 Hz, 1H, Ar H), 6.41 (dd, J = 7.8, 1.9 Hz, 1H, Ar H), 6.26 (dd, J = 7.8, 1.9 Hz, 1H, Ar H), 4.06−3.95 (m, 1H; CH 2 ), 3.26−2.86 (m, 7H; CH 2 ). Next, 4-formyl[2.2]paracyclophane (7.4 g, 31.3 mmol) was dissolved in methyl alcohol (200 mL), and tetrahydrofuran (10 mL).…”

“…After filtration and solvent removal, the product was purified on silica gel using n-hexane and ethyl acetate to yield 4-hydroxymethyl[2.2]paraclophane as white crystals (6.5 g, 87.1%). 1 Preparation of LC Substrates. ITO patterned IPS glass substrates (1.5 cm × 1.5 cm) were rinsed with acetone, ethanol, and DI water.…”

“…Liquid crystals (LCs) have been a prominent soft material from the golden age of the display industry to the recent era demanding novel materials with tunable physical properties in an on/off but dynamic manner. − It is attributed to the intrinsic physical properties of LC materials, which can be easily switchable under various external stimuli, such as light, − temperature, − electric, − and magnetic sources, − making them indispensable against other hard matters. Whereas current research on LCs is limited to molecules’ uniaxial or relatively simple alignment, LCs can also form defect structures with distorted arrangements. − These defect structures have contributed to vortex generation, − diffraction grating, ,,, lithographic tools, − and particle manipulation. − Therefore, exploring the potential of LCs beyond uniaxial alignment can open up new opportunities for their utilization in various applications.…”

A Fast-Response and Helicity-Dependent Lens Enabled by Micro-Patterned Dual-Frequency Liquid Crystals

“…[1][2][3]. Several practical LC techniques, such as zone-patterned structures [4], hole or hybrid-patterned electrodes [5][6][7][8][9], and inhomogeneous polymer networks [10], have been proposed for lens fabrication.…”