Unraveling the Mystery of the Blue Fog: Structure, Properties, and Applications of Amorphous Blue Phase III

Abstract

The amorphous blue phase III of cholesteric liquid crystals, also known as the "blue fog," are among the rising stars in materials science that can potentially be used to develop next-generation displays with the ability to compete toe-to-toe with disruptive technologies like organic light-emitting diodes. The structure and properties of the practically unobservable blue phase III have eluded scientists for more than a century since it was discovered. This progress report reviews the developments in this field from both fundamental and applied research perspectives. The first part of this progress report gives an overview of the 130-years-long scientific tour-de-force that very recently resulted in the revelation of the mysterious structure of blue phase III. The second part reviews progress made in the past decade in developing electrooptical, optical, and photonic devices based on blue phase III. The strong and weak aspects of the development of these devices are underlined and criticized, respectively. The third- and-final part proposes ideas for further improvement in blue phase III technology to make it feasible for commercialization and widespread use.

Nonlinear Rheology and Fracture of Disclination Network in Cholesteric Blue Phase III

“…However, absence of the platelet texture and dark blue texture do not always indicate the formation of BPIII, as Kim and Chien presented [22]. Chien et al provided an accurate method to distinguish BPIII from other BPs by observing optical activity [21,24,25]. Figure 2 shows polarized microscope image at T = 35.1 • C. Image in the center was taken under crossed polarizers, while images on left and right sides were taken at deviation angle between the analyzer and polarizer of φ = ±4 • by following the method established by Chien's group [21,24].…”

“…Chien et al provided an accurate method to distinguish BPIII from other BPs by observing optical activity [21,24,25]. Figure 2 shows polarized microscope image at T = 35.1 • C. Image in the center was taken under crossed polarizers, while images on left and right sides were taken at deviation angle between the analyzer and polarizer of φ = ±4 • by following the method established by Chien's group [21,24]. Under crossed polarizers, the dark blue image is observed as other BPIII system shows [33].…”

Symmetry Breaking Induced Pockels Effect in a Tilted Field Switching BPIII Cell

“…In order to get better display performance, researchers have tried to explore the liquid-crystal phase with chirality. Recent studies have focused on an intrinsic optical-isotropic phase in liquid crystal materials blue phases (BPs) [1][2][3][4][5][6][7][8]. When the BP cell is inserted between two crossed polarizers, a perfect dark state is detected and, theoretically, the BP cell exhibits an unlimited contrast ratio for display when the BP reflection wavelength is less than the visible light.…”

Laser emission in a 3D nanoporous polymer replica of amorphous blue phase III

“…INTRODUCTION Liquid crystal phases, which were first observed by Fredrich Reinitzer in 1888, have become omnipresent in our daily life through indispensable applications such as flat panel liquid crystal displays (LCD), smart phones, tablet devices, and more recently, are even being investigated for potential applications in areas of three-dimensional displays, medical diagnostics, holography, and lab-on-a-chip devices. [1][2][3] However, when Reinitzer 1 first observed the variants of what we now know as chiral nematic or cholesteric liquid crystals, little did he know that about a century later, these materials would lead to a cornucopia of innovations in a very unique field-that of organic soft matter lasers, namely, liquid crystal lasers. A liquid crystal laser is typically composed of a liquid crystal phase and a light harvester such as a fluorescent dye where the feedback is provided by the liquid crystal, while the gain is provided by the laser dye.…”

“…When refilled with conventional nematic liquid crystals, these scaffolds can impart BPIII-like electro-optical and optical properties to the nematic liquid crystals. 2,3 In other words, nematic liquid crystals behave like BPIII when they are filled inside BPIII scaffolds. While the realization of practical BPIII devices in the realm of highresolution LCD technology has come closer to fruition, there have been no studies investigating the feasibility of using BPIII systems for photonic applications such as lasing.…”