Chameleon-Inspired Mechanochromic Photonic Elastomer with Brilliant Structural Color and Stable Optical Response for Human Motion Visualization

Flexible and stretchable electronic devices are indispensable parts of wearable devices. However, these electronics employ electrical transducing modes and lack the ability to visually respond to external stimuli, restricting their versatile application in the visualized human-machine interaction. Inspired by the color variation of chameleons' skin, we developed a series of novel mechanochromic photonic elastomers (PEs) with brilliant structural colors and a stable optical response. Typically, these PEs with a sandwich structure were prepared by embedding PS@SiO₂ photonic crystals (PCs)within the polydimethylsiloxane (PDMS) elastomer. Benefiting from this structure, these PEs exhibit not only bright structural colors, but also superior structural integrity. Notably, they possess excellent mechanochromism through lattice spacing regulation, and their optical responses are stably maintained even when suffering from 100 stretching-releasing cycles, showing superior stability and reliability and excellent durability. Moreover, a variety of patterned PEs were successfully obtained through a facile mask method, which provides great inspiration to create intelligent patterns and displays. Based on these merits, such PEs can be utilized as visualized wearable devices for detecting various human joint movements in real time. This work offers a new strategy for realizing visualized interactions based on PEs, showing huge application prospects in photonic skins, soft robotics, and human-machine interactions.

Bioinspired Supramolecular Photonic Composites: Construction and Emerging Applications

Natural organisms have evolved fascinating structural colors to survive in complex natural environments. Artificial photonic composites developed by imitating the structural colors of organisms have been applied in displaying, sensing, biomedicine, and many other fields. As emerging materials, photonic composites mediated by supramolecular chemistry, namely, supramolecular photonic composites, have been designed and constructed to meet emerging application needs and challenges. This feature article mainly introduces the constructive strategies, properties, and applications of supramolecular photonic composites. First, constructive strategies of supramolecular photonic composites are summarized, including the introduction of supramolecular polymers into colloidal photonic array templates, co-assembly of colloidal particles (CPs) with supramolecular polymers, self-assembly of soft CPs, and compounding photonic elastomers with functional substances via supramolecular interactions. Supramolecular interactions endow photonic composites with attractive properties, such as stimuli-responsiveness and healability. Subsequently, the unique optical and mechanical properties of supramolecular photonic composites are summarized, and their applications in emerging fields, such as colorful coatings, real-time and visual motion monitoring, and biochemical sensors, are introduced. Finally, challenges and perspectives in supramolecular photonic composites are discussed. This feature article provides general strategies and considerations for the design of photonic materials based on supramolecular chemistry. This article is protected by copyright. All rights reserved.