Structural Colors Go Active

Advanced Science, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 4, 2025

Abstract Structural colors find wide applications for color printing, intelligent display, filtering imaging, etc., owing to their benefits, including high resolution, stable properties, and dynamic tunability. This review first illustrates the mechanisms of structural generation, such as surface plasmon resonances, localized Fabry‐Perot Mie etc. It then proposes recent technological strategies employed realize colors. The integration with functional materials like phase‐change, along development control microfluidic chips, micro‐electro‐mechanical system drivers, microheaters, represents key approaches spectrum regulation. Furthermore, assesses performance, advantages, limitations various technologies Finally, this concluded a section on future challenges prospects in large‐area fabrication, practical applications, performance improvement. explains current typical smart windows, adaptive camouflage, sensors, explores processing methods that can achieve large‐area, high‐fidelity preparation colors, nanoimprint, deep ultraviolet lithography, immersion laser field promises advancements high‐density data storage, information encryption, broader market applications.

Language: Английский

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Hydrogel-Coated Polydimethylsiloxane with Reversible Transparency for Advanced Optical Switching

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

Published: Feb. 27, 2025

Functional soft materials that swell in water often exhibit surface wrinkling, similar to the ridges formed on human skin after prolonged immersion, typically leading reduced optical transmittance. Surprisingly, there is a scarcity of are transparent underwater yet opaque air, despite their vast potential applications such as smart windows, periscopes, and information encryption. Herein, we report hydrogel-based system comprising polyacrylamide layer polydimethylsiloxane (PDMS), demonstrating reversible transition between opacity air high transparency or wet conditions. Upon water-induced swelling, transmittance hydrogel markedly increases from 7.8% 77.1% with excellent repeatability. This behavior enables encryption decryption writing. Micro- nanostructural analysis reveals switching arises reduction local roughness upon swelling. Furthermore, when employed window, effectively reduces solar power transmission by 36%, achieving temperature 5.09 °C under direct sunlight while retaining heat absence sunlight. These findings highlight PDMS versatile platform for water-responsive devices, offering exciting opportunities encryption, interactive writing systems, energy-efficient window technologies.

Language: Английский

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Bioinspired Microhinged Actuators for Active Mechanism‐Based Metamaterials

Advanced Science, Journal Year: 2024, Volume and Issue: 12(2)

Published: Nov. 18, 2024

Abstract Mechanism‐based metamaterials, comprising rigid elements interconnected by flexible hinges, possess the potential to develop intelligent micromachines with programmable motility and morphology. However, absence of efficient microactuators has constrained ability achieve multimodal locomotion active shape‐morphing behaviors at micro nanoscale. In this study, inspiration from flight mechanisms tiny insects is drawn a biomimetic microhinged actuator integrating compliant soft hydrogel muscle. A Pseudo‐Rigid‐Body mechanical model introduced analyze structural deformation, demonstrating that hydrogel‐based microactuator can undergo significant folding while maintaining high stiffness. Furthermore, multiple actuators are combined facilitate in degrees freedom arbitrary directions. Fabricated multi‐step four‐dimensional (4D) direct laser writing technique, integrated into 2D 3D metamaterials enabling programable shape morphing. Additionally, micro‐kirigami photonic structures demonstrated show pattern transforming actuated microhinges. This bioinspired design approach opens new avenues for development mechanism‐based capable intricate behaviors.

Language: Английский

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Hydrogel‐Based Dynamic Structural Color with Optical Janus Effect for Imaging Encryption/Concealment

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

Published: Nov. 29, 2024

Abstract Structural colors are widely used due to their eco‐friendliness, stability, and precise controllability. However, achieving dynamic structural typically requires complex fabrication processes high‐quality material preparation. Here, a simple bilayer structure containing hydrogel micropattern semi‐transparent ultrathin aluminum film is proposed that achieves the color with Janus effect. Combining experimental research theoretical analysis, it found by merely controlling electron‐beam exposure dose, colors, patterns these hydrogel‐based structures can be precisely rationally designed. Additionally, thickness swellability of individually regulated, enabling imaging encryption/concealment optical The stability cyclic performance this verified. environmental sensitivity, real‐time adjustability, make suitable for applications such as secure information transmission intelligent anti‐counterfeiting labels.

Language: Английский

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