A Recent Review on Stimuli‐Responsive Hydrogel Photonic Materials

The unique optical properties of structural colors found in nature garner significant attention. Inspired by these natural phenomena, scientists develop a variety of stimuli-responsive hydrogel photonic materials with periodic structures that can adjust their structural colors in response to environmental changes. In recent years, the emergence of these materials continue to grow, showcasing potential in various advanced applications. This article reviews the latest advancements in stimuli-responsive hydrogel photonic materials, focusing on their classification, manufacturing methods, and practical applications. It provides detailed descriptions of photonic materials across different dimensions and highlights the unique optical properties derived from their periodic microstructures. Additionally, the article outlines innovative technologies that are employed in creating diverse photonic structures. These materials demonstrate sensitivity to a range of external stimuli, including temperature, humidity, pH, light exposure, and mechanical force, allowing for dynamic adjustments in both structure and performance. Furthermore, the article discusses typical applications of stimuli-responsive hydrogel photonic materials in areas such as visual sensing, anti-counterfeiting technology, and drug delivery. Last, it examines the current challenges faced in the field and offers forward-looking insights regarding the future manufacturing and application of stimuli-responsive hydrogel photonic materials.