Bioinspired Artificial Photonic Nanocrystal Skin with High Sensitivity and Mechanical Color Change Properties for Camouflage and Visual Transmission

Abstract

In order to form and regulate skin color throughout the entire visible range, chameleons use a non-close-packed arranged guanine nanocrystals in iris cells. Inspired by chameleons, PS@SiO 2 particles are embedded particles in poly(ethylene glycol) phenyl ether acrylate (PEGPEA) to prepare photonic crystal thin films. Photonic crystal films have bright structural color (reflectivity >60%), high tensile strain (ε = 70%), high sensitivity (2.16 nm/% −1 ), a fast response time (1.9 nm/ms), and a wide tuning range of reflection wavelength (Δλ = 152 nm). The unique core−shell structure of PS@SiO 2 microspheres has elasticity and stretchability. Polystyrene (PS) improves the refractive index difference between the nanometer microspheres and the elastomer matrix, making the structure color of the photonic crystal film brighter. Nondense arrays can ignore particle rearrangement under strain, making the mechanical discoloration process of thin films completely reversible. Based on these characteristics, this crystal thin film is used as a wearable sensor for the human body, which can report various actions by outputting different colors during the change process. Meanwhile, simple manufacturing processes have the potential to achieve large-scale production. So the crystal thin film has certain practical value in visual sensing, display, and anticounterfeiting.

Metadynamics Simulations of Three-Dimensional Nanocrystals Self-Assembled from Triblock Janus Nanoparticles: Implications for Light Filtering

“…Quantifying the effect of the patch width on the stability of different nanostructures and pathway for their nucleation/crystallization from solution provides the design rules for complex nanocrystals. It is worth mentioning that these colloidal nanocrystals are of technological importance for fabrication of novel devices, such as photonic bandgap materials, which have applications as optical wave guides and in optical computing, color displays and sensors, and biomedical engineering . The calculated phase diagrams provide a quantitative assessment of stabilities of different nanocrystals upon changes in temperature and pressure (density).…”

“…Such photonic bandgap materials have attracted extensive interests because of their remarkable properties such as omnidirectional reflections, optical waveguiding, and suppressed spontaneous emission . Their excellent optical properties have led to various applications such as development of high-quality optical fibers, high-performance sensors and biosensors, photocatalysis, and drug delivery, among others. The lattice constant of a photonic crystal is comparable to the bandgap wavelength.…”