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This work investigates the influence of MXene content on the mechanical and functional response of PLA‐MXene composites fabricated additively using fused deposition modeling. The mechanical, thermal, and microstructural properties of the fabricated samples are investigated considering dense and architected triply periodic minimal surfaces (TPMS) gyroid specimens. Overall, the addition of 0.25–0.5 wt% MXene is found to improve the stiffness, fracture strength, and energy absorption capabilities of the PLA. However, further increasing MXene content to 1 wt% becomes detrimental to the general performance of the composite. In terms of functional behavior, the PLA‐MXene blends developed in this work are shown to display a shape memory effect, wherein deformed samples are shown to recover their shape when submerged in hot water. The reported results provide insights into the use of PLA‐MXene in engineering applications, namely those involving impact shielding or energy absorption. [ABSTRACT FROM AUTHOR]

Biogenic gold nanoparticles (BAu NPs) synthesized using olive leaf extract were used as an additive in commercial contact lenses (BAu lens). Their antibacterial and color blindness‐correcting properties were examined. To compare the properties, gold nanocomposite contact lenses were also synthesized using the well‐known Turkevich method (TAu lens). The breath‐ in/breath‐out method was used to load the Au NPs onto commercial contact lenses. The bio‐gold nanoparticles showed good dispersion and stability within the lens hydrogel matrix. Nanoparticle loading had a negligible effect on the contact lenses' wettability and swelling properties. BAu lens filtered around 55% of visible light at 530 nm, a problematic wavelength for color blind patients. The optical filtering results were comparable with Pilestone commercial color blind correction glasses. BAu lenses also showed superior resistance against the attack of Pseudomonas aeruginosa and Staphylococcus aureus bacteria as compared to Tau lenses. As scanning electron microscopy (SEM) imaging showed, the BAu lenses showed a complete lack of surface attachment toward the bacterial colonies. This research provides a cost‐effective and scalable method of producing multi‐functional nanocomposite contact lenses with antibacterial and color blind correction properties. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (GNPs) are useful materials that may be used in a variety of applications such as colorblindness management, drug delivery, and bacteria reduction. When incorporated with optical lenses, GNPs cause an absorption dip in the transmission spectra of the lenses. Out of the aforementioned medical applications, colorblindness management is the most benefited from such spectra absorption as it can potentially block problematic wavelengths that patients suffer from and hence manage their colorblindness, where color vision deficiency (CVD), also known as colorblindness, is a congenital ocular disorder that has no current cure, and patients suffering from it rely on wearable aids that enhance their color perception by filtering out the certain wavelengths. Herein, customized gold nanocomposite contact lenses are fabricated via additive manufacturing to filter selective transmission wavelengths in the range of 540 and 560 nm. To allow selective filtering, seed‐mediated synthesis of GNPs through nine growth steps is utilized to vary the GNPs' size and plasmonic filtering properties. Thereafter, three contact lenses are fabricated with different GNPs concentrations and particle sizes. In the results of the study, it is indicated that the fabricated lenses can block certain wavelengths selectively while acquiring properties similar to commercially available eyewear. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) presents a substantial global health concern due to elevated blood glucose levels, necessitating an affordable, rapid, and reliable continuous glucose monitoring (CGM) solution. In this pursuit, a pioneering approach is introduced utilizing optical fiber (OF) sensors based on nanocomposite photonic hydrogel functionalized with phenylboronic acid (PBA) for precise CGM. The fabrication of OF sensors involves a streamlined process, involving one‐step polymerization of PBA‐based hydrogel onto a commercial fiber tip and the integration of gold nanoparticles (AuNPs) via a simple dipping process. These sensors offer robust performance within the physiological glucose range (0–20 mm), exhibiting a remarkable 25% increase in transmission intensity and a 4 nm blue shift in the surface plasmon resonance with increasing glucose concentration. Additionally, there is a noticeable elevation in reflection intensity, affirming the sensor's suitability for remote sensing applications. These results are further validated using a green laser, underlining the method's reliability. The sensors exhibit a swift 30 s response time, followed by a 5 min saturation period, for all measurements. Practicality is demonstrated through smartphone readouts, utilizing the phone's photodiode to measure optical power changes concerning various glucose concentrations. These OF sensors hold great promise for CGM integration, enhancing diabetic management. [ABSTRACT FROM AUTHOR]

Prominence of color perception in our day‐to‐day routine is unequivocally pronounced, yet visual ramifications due to color vision deficiency (CVD) or color blindness impede carriers of this disorder from functioning normally. To circumvent this deficiency, patients opt for tinted glasses/contact lenses to complement their color distinction capabilities. Red‐green color blindness, the most prevalent form of CVD, can be alleviated using such glasses/lenses that filter out problematic wavelengths (540–580 nm). Nonetheless, nearly all contact lenses established by companies and developed by researchers are tinted throughout their entire surface, causing patients discomfort and needless attention as people can easily note their deficiency. Ideally, the tint within the lens should only cover the eye's pupil as it is responsible for perceiving light. Hence herein, CVD contact lenses are fabricated by solely tinting the midportion of commercial lenses utilizing two additively manufactured molds with 4 and 8 mm‐diameter holes to emulate the humans' average pupil size. The tinted lenses filter light effectively at 530–590 nm with their transmission dip being at 558 nm. The contact lenses show excellent wettability and water retention capabilities along with demonstrating superior wavelength‐filtering properties to most of the commercial and research‐based CVD wearables. [ABSTRACT FROM AUTHOR]

Color blindness or color vision deficiency (CVD) is a congenital ocular deficiency that hampers patients' daily life activities. CVD patients rely mostly on using wearable visual aids that enhance color distinction by blocking problematic wavelengths of light. Contributing to that, this study examines the fabrication of 3D‐printed colored contact lens for color blindness management. A vat photopolymerization based 3D printing technology is utilized to fabricate the contact lenses for CVD patients. An in‐house prepared resin is mixed with a low‐cost colored ink to attain the desired blocking range (520–580 nm). The fabricated lens blocks more than 50% of light at the problematic wavelengths, along with exhibiting minimal leakage when stored and examined in water and contact lens storage solution. Average contact angle and water content values are 48° and 56%, respectively. Mechanical properties demonstrate the physical adequacy of the contact lens. The CVD filtering efficacy of the tinted contact lens and its potential as a CVD wearable is evaluated by comparing its optical performance with that of commercial products. Finally, cytotoxicity analysis of the lens to dermal fibroblast cells reveals the biocompatibility of the lens as the cell viability remains greater than 75% after 24 h. [ABSTRACT FROM AUTHOR]

Color vision deficiency (CVD) is a common ocular disorder that hampers patients' color distinction capabilities, causing difficulties in their daily life routine. Till date, a CVD cure is not developed, and treatment courses, such as gene therapy, are yet to be applied on humans. Hence, patients opt for wearable visual aids such as tinted glasses/contact lenses, which achieve the latter by filtering out problematic wavelengths for blue–yellow (440–500 nm) and red–green (540–580 nm) CVD patients, thus, enabling them to distinguish between the colors. Herein, the development of 3D printed glasses for color blindness management is reported. A commercially available highly transparent resin (>95%) is utilized, and two wavelength filtering dyes, with absorption ranges of 550–580 and 440–510 nm, respectively, are mixed with the resin. The tinted glasses are successfully 3D printed using Masked SLA 3D printer; dyes incorporated within the glasses exhibit high stability over 1‐week period. The manufactured glasses successfully block more than 50% of the undesired wavelengths along with showing high transparency (>85%) to the remaining portion of the visible light spectrum. When using the developed glasses, volunteers show substantial improvements in Ishihara test scores, which signify the potential of these glasses as CVD wearables. [ABSTRACT FROM AUTHOR]

Additive manufacturing processes are capable of fabricating optical devices, including the production of contact lenses, waveguides, and Fresnel lenses used in a variety of applications. This study presents a novel fabrication method for high‐quality Fresnel lenses through a vat photopolymerization 3D printing method. Here, the 3D printing process is integrated with the micro/nanostructure fabrication to produce 3D optical components with imprinted micro/nanostructures in a single step. This straightforward approach allows imprinting a micro‐pattern (5 μm features size) onto the flat surface of a 3D‐printed Fresnel lens, achieve light focusing properties along with holographic rainbow effects. The printed lenses achieve focal lengths within ≤8 mm deviation from the predicted values. Such holographic Fresnel lenses are highly desirable in imaging‐based miniature spectrometers for mechanoluminescence sensoring. Thus, the masked stereolithography (MSLA) based 3D printing process can produce normal and holographic Fresnel lenses, vital in optical sensing and communication. [ABSTRACT FROM AUTHOR]

Dual detection systems are of interest for rapid, accurate data collection in sensing systems and in vitro testing. We introduce an IrIII complex with a boronic acid receptor site attached to the 2‐phenylpyridine ligand as an ideal probe with photo‐ and electrochemical signals that is sensitive to monosaccharide binding in aqueous solution. The complex displays orange luminescence at 618 nm, which is reduced by 70 and 40 % upon binding of fructose and glucose, respectively. The electro‐chemiluminescent signal of the complex also shows a direct response to monosaccharide binding. The IrIII complex shows the same response upon incorporation into hydrogel matrices as in solution, thus demonstrating the potential of its integration into a device, as a nontoxic, simple‐to‐use tool to observe sugar binding over physiologically relevant pH ranges and saccharide concentrations. Moreover, the complex's luminescence is responsive to monosaccharide presence in cancer cells. [ABSTRACT FROM AUTHOR]

Contact lenses can be functionalized to offer advanced capabilities transcending their primary applications in vision correction and cosmetics. Herein, 40 and 60 nm spherical silver nanoparticles (SNPs) are integrated within poly(2‐hydroxyethyl methacrylate) (pHEMA) contact lenses toward fabrication of SNP‐loaded contact lenses with excellent optical and material properties as wearables for blue‐yellow color vision deficiency (CVD) patients. The morphology and optical properties of the SNPs are characterized prepolymerization using the transmission electron microscopy (TEM) and an optical spectrophotometer. Then, the transmission spectra of the SNP‐loaded contact lenses at different concentrations along with the wettability and water content are measured, to demonstrate the effect of NPs' addition on the lenses' optical and material characteristics. Results indicate that the transmission spectra of SNP‐loaded contact lenses, with optimum concentrations, filter out problematic wavelengths of visible light (485–495 nm), which will facilitate better color distinction for blue‐yellow CVD patients. The contact lenses' optical properties are analogous to the commercial colorblind glasses, indicating their effectiveness as color filtering wearables. Finally, the cytobiocompatability analysis of the contact lenses to RAW 264.7 culture of cells shows that they are biocompatible, and the cell viability remains higher than 75% after 24 h in contact with the lenses. [ABSTRACT FROM AUTHOR]

Early detection of increasing values of intraocular pressure (IOP) due to glaucoma can prevent severe ocular diseases and ultimately, prevent loss of vision. Currently, the need for an accurate, mobile measurement of IOP that shows no correlation to central corneal thickness is unmet within the modern healthcare practices. There is a potential to utilize soundwaves as a mobile measurement method and therefore, the relationship between IOP and the reflection coefficient of sound waves is investigated. Simulations are conducted using COMSOL Multiphysics to provide theoretical confirmation of the worthiness of the experiment. An experiment is conducted to further investigate the relationship between the internal pressure of an object and its acoustic reflection coefficient. The experiment exploits the use of hydrostatic pressure to determine internal pressure, and the reflection coefficient is measured and analyzed. An initial experiment is conducted to identify the resonant frequency of the object and the optimal frequency for maximizing reflection. The experiment shows comprehensively that there is a relationship between the internal pressure of an object and its acoustic reflection coefficient, providing a confirmation of the theory that would allow mobile measurements of IOP to be conducted with the use of a smart phone. [ABSTRACT FROM AUTHOR]

Metalenses on a flexible template are engineered metal‐dielectric interfaces that improve conventional imaging system and offer dynamic focusing and zooming capabilities by controlling the focal length and bandwidth through a mechanical or external stretch. However, realizing large‐scale and cost‐effective flexible metalenses with high yields in a strain‐multiplex fashion remains as a great challenge. Here, single‐pulsed, maskless light interference and imprinting technique is utilized to fabricate reconfigurable, flexible metalenses on a large‐scale and demonstrate its strain‐multiplex tunable focusing. Experiments, in accordance with the theory, show that applied stretch on the flexible‐template reconfigurable diffractive metalenses (FDMLs) accurately mapped focused wavefront, bandwidth, and focal length. The surface relief metastructures consisted of metal‐coated hemispherical cavities in a hexagonal close‐packed arrangement to enhance tunable focal length, numerical aperture, and fill factor, FF ≈ 100% through normal and angular light illumination with external stretch. The strain‐multiplex of FDMLs approach lays the foundation of a new class of large‐scale, cost‐effective metalens offering tunable light focusing and imaging. [ABSTRACT FROM AUTHOR]

Additive manufacturing (3D printing) has the ability to architect structures at microscale, giving rise to the development of functional contact lenses (CLs) with inbuilt sensing capabilities. 3D printing technology enables fabrication of CLs without surface geometry restrictions. Spherical, nonspherical, symmetric, and asymmetric lenses can be manufactured in an integrated production process. Advantages of 3D printing over conventional techniques include fast and easy production, one‐step manufacturing, and no post processing such as grinding or polishing. In addition, and most significantly, 3D printing can create chambers within the wall of the lenses by taking the advantage of computer‐aided modeling and layer‐by‐layer deposition of the materials. These inbuilt chambers can be used for loading drugs and sensing elements. The computer‐aided design modeling can allow for manufacturing of patient‐specific CLs. This article focuses on the 3D‐printing approaches and the challenges faced in fabricating CLs. 3D‐printing technology as a technique for manufacturing of CLs is discussed, in addition to the manufacturing challenges and the possible solutions to overcome the obstacles. [ABSTRACT FROM AUTHOR]

Color blindness or color vision deficiency (CVD) affects around 4.5% of the population in Europe. There have been several attempts to assist color‐blind individuals using color filter glasses. Here, contact lenses are developed to assist individuals suffering from color blindness. Two dyes (Atto 488 and 565) that provide the desired absorption wavelength ranges are selected to be immobilized in soft contact lenses. The chosen dyes have absorption bands in wavelength ranges of 480–500 and 550–580 nm. Both dyes are individually immobilized in contact lenses, and over 95% of the light in the undesired ranges are blocked. The dyes do not diffuse out from lenses in artificial tears and contact lens storage solution. Performances of the developed contact lenses are compared to commercial color‐blind glasses. The contact lenses are tested in color vision deficient patients using Ishihara test. Participants indicate enhancement in the visibility of the colors and their contrast in a color rich environment. The proposed contact lenses show enhanced results as compared to commercial color‐blind glasses in indoors and achieved similar outcomes outdoors. [ABSTRACT FROM AUTHOR]

Color vision deficiency (CVD) or color blindness is an ocular disorder that hinders the patients from distinguishing shades of certain colors. Color blind patients are often not considered for critical occupations (e.g., military, police) and cannot differentiate colors in public places or media (i.e., watching TV). The most common form of color blindness is red‐green, which is a result of either a missing or defective red or green photoreceptor cone. Since no cure for this disorder exists, sufferers opt for methods to enhance their color perception. The products and methods that have been developed to aid CVD patients are discussed. These technologies include contemporary work on gene therapy, tinted glasses, lenses, optoelectronic glasses, and advanced features developed on smartphones and computers. Among these wearables, tinted glasses, developed by companies such as Enchroma, are the most widely used by CVD patients. [ABSTRACT FROM AUTHOR]

Tattooing is a ubiquitous body modification involving the injection of ink and/or dye pigments into the dermis. Biosensors in the form of tattoos can be used to monitor metabolites in interstitial fluid. Here, minimally invasive, injectable dermal biosensors were developed for measuring pH, glucose, and albumin concentrations. The dermal pH sensor was based on methyl red, bromothymol blue, and phenolphthalein, which responded to a pH range from 5.0 to 9.0. The dermal glucose sensor consisted of glucose oxidase, 3,3′,5,5′‐tetramethylbenzidine, and peroxidase that detected concentrations up to 50.0 mmol L−1. The dermal albumin sensor consisted of 3′,3′′,5′,5′′‐tetrachlorophenol‐3,4,5,6‐tetrabromosulfophthalein to measure concentrations up to 5.0 g L−1. The sensors were multiplexed in ex vivo skin tissue and quantitative readouts were obtained using a smartphone camera. These sensors can be used to manage of acid–base homeostasis, diabetes, and liver failure in point‐of‐care settings. [ABSTRACT FROM AUTHOR]

Abstract: Dynamic structural coloration in Tmesisternus isabellae beetle elytra is a unique example of Bragg stack‐based wavelength tuning in response to external stimuli. The underlying principles could guide the design of quantitative optical stimuli‐responsive polymers. Existing nanofabrication techniques to create such materials are costly, time‐consuming, and require high expertise. This study reports a nanofabrication method to produce slanted Bragg stack structures in poly(acrylamide‐co‐poly(ethylene glycol) diacrylate) hydrogel films by combining laser interference lithography and silver halide chemistry in a cost‐effective and rapid process (≈10 min). The Bragg stacks consist of silver bromide nanocrystal multilayers having a lattice spacing of ≈200 nm. Upon broadband light illumination, the Bragg stacks diffract a narrow‐band peak at 520 nm at ≈10° with respect to the normal incidence. The lattice spacing of the hydrogel films can be modulated by external stimuli to shift the Bragg peak for dynamic quantitative measurements. To demonstrate the utility of this method, the Bragg stacks are functionalized with phenylboronic acid molecules. Bragg peak shift analysis allows reversible glucose sensing within a physiological dynamic range (0.0–20.0 mmol L−1) having a sensitivity of 0.2 mmol L−1. The developed Bragg stacks may have application in portable, wearable, and implantable real‐time medical diagnostics at point‐of‐care settings. [ABSTRACT FROM AUTHOR]

The authors report on the laser‐induced modification of surface properties of contact lenses. Selective areas of the surface of commercial silicon‐hydrogel contact lenses are patterned in array formats using different powers of the CO2 laser. 1D arrays of different groove densities, channels, and 2D intersecting architecture are fabricated. Contact angle measurements are carried out to measure the surface hydrophilicity, and extent of hydration is linked with the surface profile properties and the space gap between the fabricated patterns, which are controlled by the beam exposure time, beam power, and scan speed. Laser treatment of contact lenses results in improved hydration proportional to the density of laser ablated segments on the surface. The hydration time of water droplets on different lens surfaces is also recorded – all 2D patterned lenses show faster hydration as water quickly diffused into the bulk of the lens due to the extended interfacial area between the contact lens and the water droplet as a consequence of larger areal modification in 2D as compared with 1D patterns. The best wettability properties are obtained with 0.3 mm space gap, 9 W power, and 200 mm s−1 scan speed. Optical microscopy is used to image the 3D surface profiles of the modified lenses and the depth of the patterns and is correlated with the experimental observations. The maximum depth of 40 µm is observed with 0.3 mm space gap, 9 W, and 200 mm s−1 scan speed. Optical transmittance of broadband white light is measured to assess the surface treatment effects on the contact lenses. A large exposure and dense patterning of contact lens result in decreased (down to a minimum of 45%) in the light transmittance, which dictates the practical usability of such patterning. Surface treatment of contact lenses can be utilized to deposit stable conducting connection for on‐lens‐LEDs, displays, and communication antennas as well as for stabilizing biosensing materials and drug dispensing applications. [ABSTRACT FROM AUTHOR]

Abstract: The Nicobar pigeon (Caloenas Nicobarica) belongs to the extinct dodo‐bird family and has been declared as an endangered species. Here, microscopic and spectroscopic measurements are carried out on the bird's feathers to study the structural coloration originating from the barbule nanostructures. A range of color shades is recorded with changing viewing and illumination angles at different locations of the feathers. A spectacular variation in colors is generated by photonic structures; red, green, and blue and their blends are observed. Hydrophobicity of the optical material is also investigated. A contact angle of ≈156° is observed demonstrating it to be superhydrophobic. Experimental observations of the optical properties are analyzed on these feathers for sensing made possible due to the material and structural properties at the interface between barbule's surface and solution. An optical response is observed with a redshift in optical spectra with increasing refractive index of the solution, which is correlated with concentration values. The structural coloration in Nicobar pigeon can be adopted for many practical applications such as color selective filters, nonreflecting coatings, and refractive index‐based sensing. [ABSTRACT FROM AUTHOR]

Abstract: A blend of two hole‐dominant polymers is created and used as the light emissive layer in light‐emitting diodes to achieve high luminous efficiency up to 22 cd A−1. The polymer blend F81−xSYx is based on poly(9,9‐dioctylfluorene) (F8) and poly(para‐phenylene vinylene) derivative superyellow (SY). The blend system exhibits a preferential vertical concentration distribution. The resulting energy landscape modifies the overall charge transport behavior of the blend emissive layer. The large difference between the highest unoccupied molecular orbital levels of F8 (5.8 eV) and SY (5.3 eV) introduces hole traps at SY sites within the F8 polymer matrix. This slows down the hole mobility and facilitates a balance between the transport behavior of both the charge carriers. The balance due to such energy landscape facilitates efficient formation of excitons within the emission zone well away from the cathode and minimizes the surface quenching effects. By bringing the light‐emission zone in the middle of the F81−xSYx film, the bulk of the film is exploited for the light emission. Due to the charge trapping nature of SY molecules in F8 matrix and pushing the emission zone in the center, the radiative recombination rate also increases, resulting in excellent device performance. [ABSTRACT FROM AUTHOR]

Abstract: Optical waveguides allow propagating light through biological tissue in optogenetics and photomedicine applications. However, achieving efficient light delivery to deep tissues for long‐term implantation has been limited with solid‐state optical fibers. Here, a method is created to rapidly fabricate flexible, functionalized soft polymer optical fibers (SPOFs) coupled with silica fibers. A step‐index core/cladded poly(acrylamide‐co‐poly(ethylene glycol) diacrylate)/Ca alginate SPOF is fabricated through free‐radical polymerization in a mold. The SPOF is integrated with a solid‐state silica fiber coupler for efficient light delivery. The cladded SPOF shows ≈1.5‐fold increase in light propagation compared to the noncladded fiber. The optical loss of the SPOF is measured as 0.6 dB cm−1 at the bending angle of 70° and 0.28 dB cm−1 through a phantom tissue. The SPOF (inner Ø = 200 µm) integrated with a 21 gauge needle (inner Ø = 514 µm) is inserted within a porcine tissue. The intensity of light decreases ≈60%, as the SPOF is implanted as deep as 2 cm. Doped with fluorescent dye and gold nanoparticles, the SPOF fiber exhibits yellow‐red and red illumination. Living cells can also be incorporated within the SPOF with viability. The flexible SPOFs may have applications in photodynamic light therapy, optical biosensors, and photomedicine. [ABSTRACT FROM AUTHOR]

The wing scales of Morpho butterflies contain 3D nanostructures that produce blue iridescent colors. Incident light is diffracted from multilayered nanostructures to create interference effects and diffract narrow‐band light. The intensity of the diffracted light remains high over a wide range of viewing angles. Structural coloration originating from the scales of Morpho wing nanostructures has been studied to analyze its optical properties and to produce scalable replicas. This review discusses computational and experimental methods to replicate these nanoarchitectures. Analytical and numerical methods utilized include multilayer models, the finite element method, and rigorous coupled‐wave analysis, which enable the optimization of nanofabrication techniques involving biotemplating, chemical vapour deposition, electron beam lithography, and laser patterning to mimic the wing scale nanostructure. Dynamic tunability of the morphology, refractive index, and chemical composition of the Morpho wing scales allows the realization of a numerous applications. [ABSTRACT FROM AUTHOR]

ABSTRACT A mixture of two polymer materials, poly (9,9-dioctylfluorene) (F8), and one of the poly( para-phenylenevinylene) derivatives, superyellow (SY) have been used to make F81− x:SY x polymer blend system. Under a 3-5 ns pulsed-laser excitation, this system showed excellent optical properties with low threshold values of ≈14 µJ/cm2 and ≈8 µJ/cm2 for amplified spontaneous emission and optically pumped lasing, respectively. The proposed system was also electroluminescent and an interesting candidate for future research on polymer injection lasers. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 15-21 [ABSTRACT FROM AUTHOR]

A fundamental study of visible diffraction effects from patterned graphene layers is presented. By patterning graphene into optical gratings, visible diffraction from graphene is experimentally measured as a function of the number of layers and visible wavelengths. A practical application of these effects is also presented, by demonstrating an optical hologram based on graphene. A high resolution (pixel size 400 nm) intensity hologram is fabricated which, in response to incident laser light, generates a visible image. These findings suggest that visible diffraction in graphene can find practical application in holograms and should also be considered during the design and characterisation of graphene‐based optical applications. [ABSTRACT FROM AUTHOR]

A hybrid liquid crystal and carbon nanotube‐based device which shows the capacity to perform as a switchable diffraction grating is demonstrated. A liquid crystal layer was sandwiched between two electrodes (patterned into gratings). The bottom electrode consists of a two dimensional square array of carbon nanotubes, while the top electrode comprises an ITO‐based in‐plane switching electrode on glass. The carbon nanotubes, due to their high aspect ratios, produce defects within the liquid crystal layer, producing a two dimensional grating. The device displays distinct voltage‐dependent diffraction patterns due to the two different electrodes. The diffraction patterns are studied both computationally and experimentally, with good agreement between the results obtained. Both the diffraction pattern and efficiency from the device could be switched by varying the applied voltage across the liquid crystal layer. [ABSTRACT FROM AUTHOR]

Thermochromic materials (TCMs) change their color in response to temperature variations. Here, presented is a rare combination of TCMs with conventional corner‐cube retroreflectors (CCRs) that are widely used in industry for their ability to return an incident beam of light directly back toward its source. The TCM quoted CCR (TCR sensor) allows remote measurements of the quantitative thermal information of the environment to which the TCR sensor is subjected. Two different commercially available thermochromic systems, a leuco dye and liquid crystals, are utilized as sensing materials. Since the incident (probe) beam and reflected (sensing) beam always follow the opposite directions 180°, this allows the probing and sensing to be carried out remotely from the same spot. Therefore, such remote sensing mechanism is virtually independent of the incident and detection beam angles. The TCR sensor has potential application in the space research, mining, power generation facilities, radioactive environments, and other industries where remote temperature sensing is a stringent requirement. A remote temperature sensor is developed by applying thermochromic materials on three mutually perpendicular planes of a corner cube retroreflector. Beams of visible monochromatic or broadband light are used as probes, which contain temperature information from the reflecting planes. The sensor is capable of measuring temperature virtually from any angle. [ABSTRACT FROM AUTHOR]