摘要
Despite the elaborate varieties of iridescent colors in biological species, most of them are reflective. Here we show the rainbow-like structural colors found in the ghost catfish ( Kryptopterus vitreolus ), which exist only in transmission. The fish shows flickering iridescence throughout the transparent body. The iridescence originates from the collective diffraction of light after passing through the periodic band structures of the sarcomeres inside the tightly stacked myofibril sheets, and the muscle fibers thus work as transmission gratings. The length of the sarcomeres varies from ~1 μm from the body neutral plane near the skeleton to ~2 μm next to the skin, and the iridescence of a live fish mainly results from the longer sarcomeres. The length of the sarcomere changes by ~80 nm as it relaxes and contracts, and the fish shows a quickly blinking dynamic diffraction pattern as it swims. While similar diffraction colors are also observed in thin slices of muscles from non-transparent species such as the white crucian carps, a transparent skin is required indeed to have such iridescence in live species. The ghost catfish skin is of a plywood structure of collagen fibrils, which allows more than 90% of the incident light to pass directly into the muscles and the diffracted light to exit the body. Our findings could also potentially explain the iridescence in other transparent aquatic species, including the eel larvae ( Leptocephalus ) and the icefishes (Salangidae).
出版物
Proceedings of the National Academy of Sciences 2023, 120 (12)
副教授
我的研究关注软功能材料中的介观结构调控及其光学、热学与力学功能。我们以胶体、颗粒组装和聚合物复合体系为主要材料平台，研究剪切、弯曲、拉伸和循环形变等外部力学场如何驱动微结构重排、结晶、晶格转变与取向选择，并进一步调控材料的结构色、光谱响应、热辐射特性和力学响应。通过将软物质物理、可规模化加工和结构—性能分析相结合，研究旨在发展可编程软光子材料与功能涂层，为自适应光学表面、光热调控、传感和机械编码材料提供新的设计思路.
