3D-Helical Artificial Chromatophore for Thermally-Tunable Fluorescence and Omnidirectional Stealth Switching.xlsx

This paper presents a bio-inspired thermochromic actuator that mimics natural camouflage systems by switching between visible and stealth modes in response to temperature changes. Thus, the innovation of this research involves a yarn-based artificial muscle with a helical structure that enables rapid switching between visible and stealth modes through vertical contraction and expansion. Unlike previous systems that rely on mechanical stimuli, this design uses thermal energy to trigger dynamic color changes. Selective surface coating with Rhodamine B and titanium dioxide (TiO₂) enables differential photo-reactivity to ultraviolet-visible (UV) light and forms the basis for rapid and reversible chromatic transitions. When exposed to an external thermal impulse, the artificial chromatophore—measuring 1400 μm in thickness—can rotate up to 309°, exhibit a negative strain of 84.6%, and reach an average actuation velocity of 297.4 μm/s/°C. This performance is among the fastest reported for color-tunable materials. Notably, the system’s thermally induced color change is effective not only in air but also in completely different environments, including underwater. This advanced approach is expected to broaden the application of adaptive materials in various industrial industries, including space and deep-sea sensors, military stealth and adaptive camouflage, temperature-regulating smart textiles for nighttime use, and smart ocean buoys.

本研究提出一款受生物启发的热致变色致动器（thermochromic actuator），其可响应温度变化在可视模式与隐身模式间切换，以此模拟自然伪装系统的运作机制。本研究的创新核心在于开发了一款具备螺旋结构的纱线基人工肌肉（yarn-based artificial muscle），可通过垂直收缩与膨胀实现可视与隐身模式的快速切换。相较于以往依赖机械刺激的同类系统，本设计通过热能触发动态色彩变化。通过在表面选择性涂覆罗丹明B（Rhodamine B）与二氧化钛（titanium dioxide, TiO₂），该装置可对紫外-可见光（ultraviolet-visible, UV）产生差异化光反应，为快速可逆的色彩转变奠定核心基础。当受到外部热脉冲刺激时，厚度达1400 μm的人工色素细胞（artificial chromatophore）可实现最高309°的旋转，呈现84.6%的负应变，平均致动速率可达297.4 μm/s/°C。该性能跻身已公开报道的色彩可调材料的顶尖性能之列。值得关注的是，该系统的热致色彩变化不仅在大气环境中可正常工作，在水下等完全迥异的环境中同样表现稳定。该先进方案有望拓展自适应材料在多领域工业场景中的应用，包括航天与深海传感器、军事隐身与自适应伪装、夜间温控智能纺织品以及智能海洋浮标。