Pretilt angle modulation of liquid crystals based on single crystal rubrene with incorporation of homeotropic polyimides.

The alignment control of liquid crystals (LCs) is critical for various practical applications. The pretilt angle modulation of LCs typically requires a mechanical rubbing on substrates to orient the LCs. This study presents a contact-free approach to achieve pretilt angle modulation of LCs.

Predicting Lung Cancer Survival to the Future: Population-Based Cancer Survival Modeling Study.

Background: Lung cancer remains the leading cause of cancer-related mortality globally, with late diagnoses often resulting in poor prognosis. In response, the Lung Ambition Alliance aims to double the 5-year survival rate by 2025.

Objective: Using the Taiwan Cancer Registry, this study uses the survivorship-period-cohort model to assess the feasibility of achieving this goal by predicting future survival rates of patients with lung cancer in Taiwan.

Integrating predictive coding and a user-centric interface for enhanced auditing and quality in cancer registry data.

Data curation for a hospital-based cancer registry heavily relies on the labor-intensive manual abstraction process by cancer registrars to identify cancer-related information from free-text electronic health records. To streamline this process, a natural language processing system incorporating a hybrid of deep learning-based and rule-based approaches for identifying lung cancer registry-related concepts, along with a symbolic expert system that generates registry coding based on weighted rules, was developed. The system is integrated with the hospital information system at a medical center to provide cancer registrars with a patient journey visualization platform.

Laser beam homogenization based on a multifocal liquid crystal microlens array.

A novel, to the best of our knowledge, tunable multifocal liquid crystal microlens array (TMLCMA) was fabricated with a triple-electrode structure consisting of a large-hole, a small-hole array, and planar electrodes. The electro-optical performances of the TMLCMA are characterized, demonstrating the monofocal convex, multifocal convex, and multifocal concave functions when the TMLCMA is manipulated with various driving schemes. Furthermore, the homogenization of a laser beam is realized using the fabricated TMLCMA.

Polarization-insensitive tunable multifocal liquid crystal microlens array with dual lens modes.

Microlens has significant applications in integrated micro-optical systems. Recently, multifocal microlens arrays are expected to extend the depth of field for imaging systems and realize a highly efficient laser beam homogenizer. This work presents what we believe to be a novel approach for developing a tunable multifocal liquid crystal microlens array (TMLCMA), which can be operated in convex and concave modes through voltage control schemes.

Polarization-insensitive liquid crystal Fresnel lens based on self-assembly polymer gravels and chiral dopant.

A polarization-insensitive liquid crystal (LC) Fresnel lens is developed with binary LC configurations of 90°-twisted nematic (TN) and vertically-aligned (VA) domains in the adjacent zones. A LC mixture comprised of nematic host, photopolymer and chiral material is initially filled into the VA cell with orthogonal rubbing treatment. After the ultraviolet irradiation on the filled LC cell through a photomask with Fresnel zone plate pattern, the interactions among orthogonal rubbing treatment, self-assembly polymer gravels, and chiral material induce the 90-TN structure in the odd zones, whereas the initial VA structures are maintained in the even zones.

Tunable focal waveguide-based see-through display with negative liquid crystal lens.

A see-through display based on a planar holographic waveguide with a tunable focal plane is presented. A negative liquid crystal lens is attached on the outcoupling location of the waveguide to manipulate the image distance. The continuous tunable range for the focal length is from negative infinity to -65 cm.

Rubbing-free liquid crystal electro-optic device based on organic single-crystal rubrene.

Liquid crystals (LCs) have been a vital component of modern communication and photonic technologies. However, traditional LC alignment on polyimide (PI) requires mechanically rubbing treatment to control LC orientation, suffering from dust particles, surface damage, and electrostatic charges. In this paper, LC alignment on organic single-crystal rubrene (SCR) has been studied and used to fabricate rubbing-free LC devices.

Superior improvement in dynamic response of liquid crystal lens using organic and inorganic nanocomposite.

In this study, the response time of a 4 mm-aperture hole-patterned liquid crystal (HLC) lens has been significantly improved with doping of N-benzyl-2-methyl-4-nitroaniline (BNA) and rutile titanium dioxide nanoparticle (TiO NP) nanocomposite. The proposed HLC lens provides the focus and defocus times that are 8.5× and 14× faster than the pristine HLC lens, respectively.

A Comparative Study on Electro-Optic Effects of Organic N-Benzyl-2-Methyl-4-Nitroaniline and Morpholinium 2-Chloro-4-Nitrobenzoate Doped in Nematic Liquid Crystals E7.

Improvements in electro-optical responses of LC devices by doping organic N-benzyl-2-methyl-4-nitroaniline (BNA) and Morpholinium 2-chloro-4-nitrobenzoate (M2C4N) in nematic liquid crystals (LCs) have been reported in this study. BNA and M2C4N-doped LC cells have the fall time that is fivefold and threefold faster than the pristine LC cell, respectively. The superior performance in fall time of BNA-doped LC cell is attributed to the significant decrements in the rotational viscosity and threshold voltage by 44% and 25%, respectively, and a strong additional restoring force resulted from the spontaneous polarization electric field of BNA.

Electro-optical effects of organic N-benzyl-2-methyl-4-nitroaniline dispersion in nematic liquid crystals.

The dispersion of organic N-benzyl-2-methyl-4-nitroaniline (BNA) in nematic liquid crystals (LCs) is studied. BNA doping decreases the threshold voltage of cell because of the reduced splay elastic constant and increased dielectric anisotropy of the LC mixture. When operated in the high voltage difference condition, the BNA-doped LC cell has a fall time that is five times faster than that of the pure one because of the decrements in the threshold voltage of the cell and rotational viscosity of the LC mixture.

Liquid crystal lens with doping of rutile titanium dioxide nanoparticles.

A 4 mm-aperture hole-patterned liquid crystal (LC) lens has been fabricated using a LC mixture, which consisted of rutile titanium dioxide (TiO) nanoparticles (NPs) and nematic LC E7, for the first time. The TiO NP dopant improves the addressing and operation voltages of the LC lens significantly because it strengthens the electric field surrounding the TiO NP and increases the capacitance of lens cell. Unlike the doping of common colloidal NPs, that of rutile TiO NPs increases the phase transition temperature and birefringence of the LC mixture, thereby helping enhance the lens power of LC lens.

Low-voltage tunable liquid crystal lens fabricated with self-assembled polymer gravel arrays.

A novel approach for fabricating liquid crystal (LC) lenses is presented. The approach involves the use of a photocurable prepolymer dispersed in a cell fabricated with vertically aligned substrates. A radial gradient UV irradiation intensity distribution is produced using a radial variable neutral density filter.

Fast-response liquid crystal lens with doping of organic N-benzyl-2-methyl-4-nitroaniline.

In this study, a large-aperture hole-patterned liquid crystal (LHLC) lens was prepared from a mixture of nematic liquid crystal (NLC, E7) and organic material (N-benzyl-2-methyl-4-nitroaniline, BNA). The electro-optic properties of doped and undoped samples were measured, compared, and analyzed. The doped sample exhibited a response time that was ∼6 times faster than that of the undoped sample because BNA doping decreased the rotational viscosity of the NLC.

Large aperture liquid crystal lens with an imbedded floating ring electrode.

We propose a hole-patterned large aperture (LA) liquid crystal (LC) lens with a diameter of 6 mm. In our design, a floating ring electrode is embedded into the interface between the dielectric layer and the LC layer. This structure increases the electric field strength around the floating ring electrode located near the aperture center and assists in distributing the fringing electric field throughout the LC layer.

Controlling liquid crystal pretilt angle with photocurable prepolymer and vertically aligned substrate.

We demonstrate a new approach to control the pretilt angle of liquid crystals (LCs) with photocurable prepolymer in a cell fabricated with vertically aligned substrates. During UV exposure, prepolymer approaches and is polymerized on the substrate surfaces because of the vertical phase separation induced by differences in the surface tensions of the employed materials. After polymerization, the polymer structure formed on the substrate alters its surface polarity and changes the pretilt angle of the LC cell.

Polarization-insensitive liquid crystal microlens array with dual focal modes.

We demonstrate a liquid crystal (LC) microlens array (MLA) fabricated by LCs possessing negative dielectric anisotropy, in conjunction with a cell with a three-electrode structure. The presented LC MLA is polarization-insensitive and can be operated in both concave and convex modes. The shortest focal length of the LC MLA is -2.

Carbodimide cross-linked and biodegradation-controllable small intestinal submucosa sheets.

The small intestinal submucosa (SIS) is an acellular collagen-based matrix, primarily composed of fibrillar collagens (types I, II, and V). They enhance healing due to a minimal immune response. A good degradation rate is the degradation of materials equal to the rate of remodeling in the host.

Effects of silica nanoparticles on electro-optical properties of polymer-stabilized liquid crystals.

We control the pretilt angle of liquid crystals (LCs) by simultaneously doping silica nanoparticles (SNs) and reactive monomers into the LC cell. Application of AC high voltage (ACHV) to the cell compels the lifting force and the facilitation of polar groups to move the SNs and monomers toward the substrate surface. Polymer networks and SNs are stabilized at the substrate surface after UV exposure, sustaining the LCs at high pretilt angles.

Electrically switchable cholesteric gratings based on slit electrodes.

An electrically switchable diffraction grating (ESDG) based on cholesteric liquid crystal (CLC) filled into the cell with slit electrodes is demonstrated in this study. On one hand, with low voltage, the ESDG has high second order diffraction efficiency because of the alternating planar and fingerprint textures. With high voltage, on the other hand, the ESDG has high first order diffraction efficiency because of the alternating planar and homeotropic textures.

Polarization-independent distortion corrector fabricated using polymer-dispersed liquid crystals.

We demonstrate a polarization-independent distortion corrector fabricated using a polymer-dispersed liquid crystal (PDLC) cell placed on the intermediate image plane of an optical system. At low voltage, a hazy PDLC cell scatters the incident rays and redirects the off-axis propagated chief ray. The chief ray approaches the principal point of the lens element, thereby decreasing image distortion.

Distortion aberration correction device fabricated with liquid crystal lens array.

A distortion aberration (DA) correction device is fabricated using a liquid crystal lens array (LCLA), which is placed at the intermediate image plane of the optical system. Without voltage, the LCLA does not work, the image is distorted due to the aberration from the optical system; with voltage, the incident light is focused by the LCLA and then the distorted image is corrected. The correction of distorted image by LCLA is attributed to the redirection of the off-axis propagated chief ray approaches the principal point of the lens element.

Rotatable diffractive gratings based on hybrid-aligned cholesteric liquid crystals.

This work proposes a thermally rotatable grating that is based on hybrid-aligned cholesteric liquid crystals (HBA-cholesteric LCs). Experiments reveal that the HBA-cholesteric texture has a uniformly striped domain, which forms a grating, when the ratio of the cell gap to the helical pitch (d/p) is in the range of 2≤d/p≤3. The stripe direction of the HBA-cholesteric grating is predicted by the proposed vertically aligned LC layer model.

Influence of pretilt angle on disclination lines of liquid crystal lens.

This article investigates the effect of pretilt angle on disclination lines of liquid crystal (LC) lenses. When the pretilt angle of LCs is higher than 7°, the disclination lines are reduced and are moved to the boundary of the LC lens. The disclination lines at the boundary do not influence the focused beam profile of the LC lens.