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Bioinspired Melanin‐Based Optically Active Materials

Melanin is a widespread multifunctional biological pigment that has emerged as a promising platform for applications in coating, catalysis, energy, drug delivery, and medical therapy. Melanin is also a compelling material for photonic applications because of its favorable material characteristics, including broadband absorption, high refractive index, tunable fluorescence, and UV blocking capabilities. However, there is not yet a critical review focusing on optical functions of melanin. This review summarizes current advances in bioinspired melanin‐based optically active materials, covering melanin's inherent optical properties and functions both in nature and in optics‐related applications. It is envisioned that this work will provide a better understanding of melanin's photonic functions and insights into the future development of melanin‐based or melanin‐inspired optically active materials for wide applications.