Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
Centre for Processable Electronics, Imperial College London, London SW7 2AZ, UK.
Molecules. 2023 Feb 10;28(4):1710. doi: 10.3390/molecules28041710.
We investigate the combined effects of surface diffraction and total internal reflection (TIR) in the design of 3-dimensional materials exhibiting distinct structural colour on various facets. We employ mechanical wrinkling to introduce surface diffraction gratings (from the nano to the micron scales) on one face of an elastomeric rectangular parallelepiped-shaped slab and explore the roles, in the perceived colours, of wrinkling pattern, wavelength, the directionality of incident light and observation angles. We propose a simple model that satisfactorily accounts for all experimental observations. Employing polydimethylsiloxane (PDMS), which readily swells in the presence of various liquids and gases, we demonstrate that such multifaceted colours can respond to their environment. By coupling a right angle triangular prism with a surface grating, we demonstrate the straightforward fabrication of a so-called GRISM (GRating + prISM). Finally, using a range of examples, we outline possibilities for a predictive material design using multi-axial wrinkling patterns and more complex polyhedra.
我们研究了表面衍射和全内反射（TIR）在设计具有不同面的三维材料上独特结构颜色的综合影响。我们采用机械褶皱在弹性矩形平行六面体板的一个面上引入表面衍射光栅（从纳米到微米级），并探索褶皱图案、波长、入射光的方向性和观察角度在感知颜色中的作用。我们提出了一个简单的模型，很好地解释了所有的实验观察结果。我们使用聚二甲基硅氧烷（PDMS），它在存在各种液体和气体时很容易膨胀，证明了这种多面颜色可以对其环境做出响应。通过将一个直角三棱镜与一个表面光栅耦合，我们演示了所谓的 GRISM（光栅+棱镜）的简单制造。最后，我们通过一系列实例，概述了使用多轴褶皱图案和更复杂的多面体进行预测性材料设计的可能性。
