Chiral Materials for Optics and Electronics: Ready to Rise?

Chiral materials have gained burgeoning interest in optics and electronics, beyond their classical application field of drug synthesis. In this review, we summarize the diverse chiral materials developed to date and how they have been effectively applied to optics and electronics to get an understanding and vision for the further development of chiral materials for advanced optics and electronics.

Trainable Bilingual Synaptic Functions in Bio-enabled Synaptic Transistors.

The signal transmission of the nervous system is regulated by neurotransmitters. Depending on the type of neurotransmitter released by presynaptic neurons, neuron cells can either be excited or inhibited. Maintaining a balance between excitatory and inhibitory synaptic responses is crucial for the nervous system's versatility, elasticity, and ability to perform parallel computing.

Bio-Templated Chiral Zeolitic Imidazolate Framework for Enantioselective Chemoresistive Sensing.

Chiral metal-organic frameworks (MOFs) have gained rising attention as ordered nanoporous materials for enantiomer separations, chiral catalysis, and sensing. Among those, chiral MOFs are generally obtained through complex synthetic routes by using a limited choice of reactive chiral organic precursors as the primary linkers or auxiliary ligands. Here, we report a template-controlled synthesis of chiral MOFs from achiral precursors grown on chiral nematic cellulose-derived nanostructured bio-templates.

Chiro-Optoelectronic Encodable Multilevel Thin Film Electronic Elements with Active Bio-Organic Electrolyte Layer.

It is suggested that chiral photonic bio-enabled integrated thin-film electronic elements can pave the base for next-generation optoelectronic processing, including quantum coding for encryption as well as integrated multi-level logic circuits. Despite recent advances, thin-film electronics for encryption applications with large-scale reconfigurable and multi-valued logic systems are not reported to date. Herein, highly secure optoelectronic encryption logic elements are demonstrated by facilitating the humidity-sensitive helicoidal organization of chiral nematic phases of cellulose nanocrystals (CNCs) as an active electrolyte layer combined with printed organic semiconducting channels.

Multivalued Logic for Optical Computing with Photonically Enabled Chiral Bio-organic Structures.

Photonic bio-organic multiphase structures are suggested here for integrated thin-film electronic nets with multilevel logic elements for multilevel computing via a reconfigurable photonic bandgap of chiral biomaterials. Herein, inspired by an artificial intelligence system with efficient information integration and computing capability, the photonically active dielectric layer of chiral nematic cellulose nanocrystals is combined with printed-in p- and n-type organic semiconductors as a bifunctional logical element. These adaptive logic elements are capable of triggering tailored quantized electrical output signals under light with different photon energy and at the different photonic bandgaps of the active dielectric layer.

Cellulose Nanocrystals' Assembly under Ionic Strength Variation: From High Orientation Ordering to a Random Orientation.

We discuss the effect of the ionic strength and effective charge density on the final structural organization of cellulose nanocrystals (CNCs) after drying suspensions with different ionic strengths in terms of quantitative characteristics of the orientation order, rarely considered to date. We observed that increasing the ionic strength in the initial suspension results in continuous shrinking of the helical pitch length that shifts the photonic band gap to a far UV region from the visible range (from 400 to 250 nm) because of the increase in the helical twisting power from 4 to 6 μm and doubling of the twisting angle between neighboring monolayers from 5.5 to 9°.

Light-Driven Fabrication of a Chiral Photonic Lattice of the Helical Nanofilament Liquid Crystal Phase.

A photonic lattice is an efficient platform for optically exploring quantum phenomena. However, its fabrication requires high costs and complex procedures when conventional materials, such as silicon or metals, are used. Here, we demonstrate a simple and cost-effective fabrication method for a reconfigurable chiral photonic lattice of the helical nanofilament (HNF) liquid crystal (LC) phase and diffraction grating showing wavelength-dependent diffraction with a rotated polarization state.

Hierarchically Fabricated Amyloid Fibers Evaporation-Induced Self-Assembly.

Multiscale hierarchical nano- and microstructures of amyloid fibrils are fabricated by evaporation-induced self-assembly combined with topographic surface patterning techniques. The continuous stick-and-slip motion induces uniaxial alignment of amyloid fibrils characterized by high orientational order during the drying process. The optical textures of the resultant amyloid aggregates are directly observed by polarized optical microscopy (POM) and atomic force microscopy (AFM).

Chiral Optoelectronic Functionalities DNA-Organic Semiconductor Complex.

We fabricate the bio-organic field-effect transistor (BOFET) with the DNA-perylene diimide (PDI) complex, which shows unusual chiroptical and electrical functionalities. DNA is used as the chirality-inducing scaffold and the charge-injection layer. The shear-oriented film of the DNA-PDI complex shows how the large-area periodic molecular orientation and the charge transport are related, generating drastically different optoelectronic properties at each DNA/PDI concentration.

Co-Assembly of Biosynthetic Chiral Nematic Adhesive Materials with Dynamic Polarized Luminescence.

There is currently an extensive demand for simple and effective synthetic methods to allow the design and fabrication of robust and flexible chiral materials that can generate strong and switchable circularly polarized luminescence (CPL). Herein, biosynthetic light-emitting adhesive materials based upon chiral nematic cellulose nanocrystal-polyelectrolyte complexes with universal high adhesion on both hydrophilic and hydrophobic substrates are reported. Strong and dynamic photoluminescence with highly asymmetric and switchable circular polarization is induced by minute rare earth europium doping without compromising adhesive strength and initial iridescent properties.

Bio-Organic Chiral Nematic Materials with Adaptive Light Emission and On-Demand Handedness.

Real-time active control of the handedness of circularly polarized light emission requires sophisticated manufacturing and structural reconfigurations of inorganic optical components that can rarely be achieved in traditional passive optical structures. Here, robust and flexible emissive optically-doped biophotonic materials that facilitate the dynamic optical activity are reported. These optically active bio-enabled materials with a chiral nematic-like organization of cellulose nanocrystals with intercalated organic dye generated strong circularly polarized photoluminescence with a high asymmetric factor.

Molecular Orientation Control of Liquid Crystal Organic Semiconductor for High-Performance Organic Field-Effect Transistors.

The control of molecular orientation and ordering of liquid crystal (LC) organic semiconductor (OSC) for high-performance and thermally stable organic thin-film transistors is investigated. A liquid crystalline molecule, 2-(4-dodecyl thiophenyl)[1]dibenzothiopheno[6,5-:6',5'-]-thieno[3,2-]thiophene (C12-Th-DBTTT) is synthesized, showing the highly ordered smectic X (SmX) phase, demonstrating molecular reorganization via thermal annealing. The resulting thermally evaporated polycrystalline film and solution-sheared thin film show high charge carrier mobilities of 9.

Orientation Control of Semiconducting Polymers Using Microchannel Molds.

The molecular orientation of organic semiconductors (OSCs) is of fundamental importance to anisotropic electrical behavior as well as superior properties in practical applications. Here, a simple and effective method is demonstrated to fabricate highly oriented semiconducting polymers, poly(3-hexylthiophene) (P3HT) and poly{[,'-bis(2-octyldodecyl)-1,4,5,8-naphthalenediimide-2,6-diyl]--5,5'-(2,2'-bithiophene)} (P(NDI2OD-T2)), by mass transfer effect under microchannel molds by diffusion and convection. Furthermore, parallel or perpendicular molecular arrangements relative to the channel direction were achieved by varying the widths of the microchannels, which are directly observed using polarized optical microscopy and two-dimensional grazing-incidence X-ray diffraction experiments.

Highly Oriented Liquid Crystal Semiconductor for Organic Field-Effect Transistors.

We report a mesogenic compound which introduces nematic liquid crystal (LC) ordering into the benzothienobenzothiophene (BTBT) family of LCs, creating a new class of LC semiconducting materials which respond in a facile way to anisotropic surfaces, and can, thereby, be effectively processed into highly oriented monodomains. Measurement on these domains of the electrical conductivity, with in situ monitoring of domain quality and orientation using LC birefringence textures in electroded cells, brings a new era of precision and reliability to the determination of anisotropic carrier mobility in LC semiconductors.

Glass and Plastics Platforms for Foldable Electronics and Displays.

Reversibly, repeatedly foldable electronics and displays are enabled by employing engineered glass or plastics substrates, where folding deformation is localized in thinned parts only. This design concept can further be extended to dual folding, leading to size reduction down to 1/4. Notably, the foldable electronics and displays can be implemented with no need to introduce any novel materials.

Frequent occurrence of mitochondrial DNA mutations in Barrett's metaplasia without the presence of dysplasia.

Background: Barrett's esophagus (BE) is one of the most common premalignant lesions and can progress to esophageal adenocarcinoma (EA). The numerous molecular events may play a role in the neoplastic transformation of Barrett's mucosa such as the change of DNA ploidy, p53 mutation and alteration of adhesion molecules. However, the molecular mechanism of the progression of BE to EA remains unclear and most studies of mitochondrial DNA (mtDNA) mutations in BE have performed on BE with the presence of dysplasia.

Increased intestinal macromolecular permeability and urine nitrite excretion associated with liver cirrhosis with ascites.

Aim: To determine intestinal permeability, the serum tumor necrosis factor (TNF)-alpha level and urine nitric oxide (NO) metabolites are altered in liver cirrhosis (LC) with or without ascites.

Methods: Fifty-three patients with LC and 26 healthy control subjects were enrolled in the study. The intestinal permeability value is expressed as the percentage of polyethylene glycol (PEG) 400 and 3350 retrieval in 8-h urine samples as determined by high performance liquid chromatography.