Left and Right‐Handed Light Reflection and Emission in Ultrathin Cellulose Nanocrystals Films with Printed Helicity

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: May 17, 2024

Abstract Natural polymers, particularly plant‐derived nanocelluloses, self‐organize into hierarchical structures, enabling mechanical robustness, bright iridescence, emission, and polarized light reflection. These biophotonic properties are facilitated by the assembly of individual components during evaporation, such as cellulose nanocrystals (CNCs), which exhibit a left‐handed helical pitch in chiral nematic state. This work demonstrates how optically active films with pre‐programmed opposite handedness (left or right) can be constructed via shear‐induced twisted printing clockwise counter‐clockwise shearing vectors. The resulting large‐area thin transparent yet pre‐determined mirror‐symmetrical optical activity, distinction absorbed emitted circularly light. processing method allows for sequential ultrathin layered organization on‐demand helicity. complex polarization behavior is due to step‐like changes linear birefringence within each deposited layer circular birefringence, different from that conventional CNC revealed Muller matrix analysis. Furthermore, intercalating an achiral organic dye printed structures induces luminescence while preserving high transmittance controlled handedness. results suggest facilitate construction chiroptical metamaterials tunable polarization, absorption, emission filters, encryption, photonic coatings, sensors.

Language: Английский

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Automatically Aligned and Environment-Friendly Twisted Stacking Terahertz Chiral Metasurface with Giant Circular Dichroism for Rapid Biosensing

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(12), P. 15193 - 15201

Published: March 16, 2024

Chiral metasurfaces are capable of generating a huge superchiral field, which has great potential in optoelectronics and biosensing. However, the conventional fabrication process suffers greatly from time consumption, high cost, difficult multilayer alignment, hinder its commercial application. Herein, we propose twisted stacking carbon-based terahertz (THz) chiral metasurface (TCM) based on laser-induced graphene (LIG) technology. By repeating two-step sticking polyimide film, followed by laser direct writing, two layers TCM aligned automatically fabrication. Laser manufacturing also brings such processing speed that with size 15 × mm can be prepared 60 s. In addition, due to greater dissipation LIG than metals THz band, giant circular dichroism (CD) +99.5 −99.6% is experimentally realized. The biosensing bovine serum albumin enhanced proposed TCMs then demonstrated. A wide sensing range (0.5–50 mg mL–1) good sensitivity [ΔCD: 2.09% (mg mL–1)−1, Δf: 0.0034 mL–1)−1] proved. This LIG-based provides an environment-friendly platform for research application rapid low-cost

Language: Английский

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Planar Chiral Metasurface Based on Coupling Quasi‐Bound States in the Continuum

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(16)

Published: April 3, 2024

Abstract Chiral metasurface based on bound state in the continuum (BIC) possesses extremely high Q factor. However, intrinsic chiral BIC only can be realized by breaking out‐of‐plane mirror symmetry with complicated 3D structures. In this work, a design of planar supporting orthogonal BICs is proposed. The coupling strength, eigenfrequency, and radiation loss two quasi‐BICs tuned parameters. By adjusting parameters, merge to an exceptional point (EP). Around EP, one transforms circular eigenstate polarization. parameter space, different elliptical polarizations same helicity wind around EP. nearly fully cover Poincaré sphere changing geometry superchiral fields will also greatly enhanced near simulation result shows dichroism at resonance frequency. provides new strategy for polarization detection light sources.

Language: Английский

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Beam Shaping by Stacked Nonlinear Moiré Metasurfaces

Nano Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 13, 2025

Moiré phenomena provide a versatile platform for creating tunable lattices with variable symmetries and periodicities, making them focal topic in recent photonics research. photonic devices fused metasurfaces have demonstrated numerous novel functionalities, yet fabricating moiré metasurfaces, particularly stacked configurations, poses significant challenges. In this paper, we present an innovative nanofabrication approach nonlinear using focused ion beam-assisted nanostructure transfer-welding technique. This allows precise control over interlayer twist angles, enabling complex momentum space engineering along simultaneous frequency conversion wavefront manipulation. Experimental results reveal intricate far-field second-harmonic radiation patterns, which are effectively by varying the angles. advancement addresses key fabrication challenges photonics, opening new avenues applications information processing, optical steering, switching.

Language: Английский

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Inverse design of chiral functional films by a robotic AI-guided system

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 4, 2023

Artificial chiral materials and nanostructures with strong tuneable chiroptical activities, including sign, magnitude, wavelength distribution, are useful owing to their potential applications in sensing, enantioselective catalysis, devices. Thus, the inverse design customized manufacturing of these is highly desirable. Here, we use an artificial intelligence (AI) guided robotic chemist accurately predict activities from experimental absorption spectra structure/process parameters, generate films targeted across full visible spectrum. The AI-chemist carries out entire process, film construction, characterization, testing. A machine learned reverse model using spectrum embedded descriptors developed optimal parameters for any property. series a dissymmetry factor as high 1.9 (gabs ~ 1.9) identified more than 100 million possible structures, feasible application circular polarization-selective color filters multiplex laser display switchable circularly polarized (CP) luminescence demonstrated. Our findings not only provide highest reported activity, but also have great fundamental value materials.

Language: Английский

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Surface Topographical Engineering of Chiral Au Nanocrystals with Chiral Hot Spots for Plasmon-Enhanced Chiral Discrimination

Nano Letters, Journal Year: 2023, Volume and Issue: 23(17), P. 8233 - 8240

Published: Aug. 17, 2023

Surface roughness in chiral plasmonic nanostructures generates asymmetrical localized electromagnetic fields, which hold great promise for applications recognition, chiroptical spectroscopic sensing, and enantioselective photocatalysis. In this study, we develop a surface topographical engineering approach to precisely manipulate the structures of Au nanocrystals. Through carefully controlling amounts l- or d-cystine (Cys) seed solution growth process, successfully synthesize nanocrystals with highly disordered, ordered, less ordered wrinkled surfaces. An underlying principle governing relationship between roughness, orderliness, response is also proposed. More importantly, wrinkles on surfaces generate electronic fields enhanced intensity, achieve excellent plasmon-enhanced discrimination ability penicillamine (Pen) enantiomers. This work offers exciting prospects manipulating designing sensitive sensors hot spots.

Language: Английский

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Continuous‐Spectrum–Polarization Recombinant Optical Encryption with a Dielectric Metasurface

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(41)

Published: July 6, 2023

The Jones matrix, with eight degrees of freedom (DoFs), provides a general mathematical framework for the multifunctional design metasurfaces. Theoretically, maximum DoFs can be further extended in spectrum dimension to endow unique encryption capabilities. However, topology and intrinsic spectral responses meta-atoms constrains continuous engineering polarization evolution over wavelength dimension. In this work, forward strategy quickly establish mapping relationships between solutions dispersion matrix is reported. Based on eigenvector transformation method, arbitrary conjugate channels continuous-spectrum are successfully reconstructed. As proof-of-concept, silicon metadevice demonstrated optical information transmission. Remarkably, combination forms increase capacity (210 ), measured contrasts conversion >94% entire range (3-4 µm). It believed that proposed approach will benefit secure quantum technologies.

Language: Английский

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Engineering chirality at wafer scale with ordered carbon nanotube architectures

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Nov. 15, 2023

Creating artificial matter with controllable chirality in a simple and scalable manner brings new opportunities to diverse areas. Here we show two such methods based on controlled vacuum filtration - twist stacking mechanical rotation for fabricating wafer-scale chiral architectures of ordered carbon nanotubes (CNTs) tunable large circular dichroism (CD). By controlling the angle handedness twist-stacking approach, maximize CD response achieve high deep-ultraviolet ellipticity 40 ± 1 mdeg nm-1. Our theoretical simulations using transfer matrix method reproduce experimentally observed spectra further predict that an optimized film twist-stacked CNTs can exhibit as 150 nm-1, corresponding g factor 0.22. Furthermore, not only accelerates fabrication twisted structures but also produces both chiralities simultaneously single sample, run, manner. The created objects represent alternative type synthetic consisting quantum wires whose macroscopic properties are governed by nanoscopic electronic signatures be used explore phenomena develop photonic optoelectronic devices.

Language: Английский

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Research Progress in Surface-Enhanced Infrared Absorption Spectroscopy: From Performance Optimization, Sensing Applications, to System Integration

Nanomaterials, Journal Year: 2023, Volume and Issue: 13(16), P. 2377 - 2377

Published: Aug. 19, 2023

Infrared absorption spectroscopy is an effective tool for the detection and identification of molecules. However, its application limited by low infrared cross-section molecule, resulting in sensitivity a poor signal-to-noise ratio. Surface-Enhanced Absorption (SEIRA) breakthrough technique that exploits field-enhancing properties periodic nanostructures to amplify vibrational signals trace The fascinating SEIRA technology have aroused great interest, driving diverse sensing applications. In this review, we first discuss three ways performance optimization, including material selection, enhancement, bandwidth improvement. Subsequently, potential applications fields such as biomedicine environmental monitoring. recent years, ushered new era characterized Internet Things, sensor networks, wearable devices. These demands spurred pursuit miniaturized consolidated systems chips. addition, rise machine learning has injected vitality into SEIRA, bringing smart device design data analysis foreground. final section review explores anticipated trajectory might take, highlighting future trends possibilities.

Language: Английский

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Nature‐Inspired Helicoidal Nanocellulose‐Based Multi‐Compartment Assemblies with Tunable Chiroptical Properties

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(29)

Published: April 18, 2024

Cellulose-based nanocomposites are highly appealing for the development of next-generation sustainable functional materials. Although many advances have been made in this direction, true potential fibrillar has yet to be realized because available fabrication approaches inadequate achieving precise structural control at sub-micrometer scale. Here a spray-assisted alignment methodology cellulose nanofibrils is combined with layer-by-layer assembly into an additive manufacturing process which direction each layer rationally selected achieve thin films helicoidal arrangement nanofibrils. The structure verified by measuring circular dichroism (CD) samples. sign and position CD peak show that handedness pitch chiral structures can easily tuned deliberately selecting simple parameters, such as number consecutive layers sprayed same angle rotation between successive stacks layers. To authors' knowledge, approach unique it offers possibility prepare complex nanocomposite architectures various nanoscale-controlled sub-structures from different anisometric objects, enabling novel designs composite damage-resistant and/or optical filtering functionalities.

Language: Английский

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