We have provided a no-touch and inexpensive technique to present the three-dimensional (3D) structure of two-dimensional (2D) films, based on the equal thickness interference fringes. In these experiments, the interference colors were obtained by an optical microscope without contact with the sample, and the 3D structures of curved 2D membranes were reconstructed by MATLAB programs in real time. The theoretical model and experimental results both showed that natural bending can improve the stiffness of 2D materials by more than 10 times. By using micro-droplets as the workbench, the 3D bending orientation and curvature of the 2D material could be manipulated and detected at the same time. The selected 3D curved shapes of cylindrical, ellipsoid and saddle surfaces can increase the bending stiffness over 10 000 times based on theoretical calculation. A saddle-shaped 3D structure (classic crisps shape) is predicted to obtain the maximum bending stiffness. Herein, a simple and practical method to comprehensively detect the basic deformation of 2D membranes is proposed, which should be promoted to explore the out-of-plane mechanical properties of 2D materials under external fields.

中文翻译：

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进行三维弯曲以通过干涉色极大地增强二维膜†

我们提供了一种非接触且廉价的技术，可以基于相等厚度的干涉条纹来呈现二维（2D）膜的三维（3D）结构。在这些实验中，通过不与样品接触的光学显微镜获得干涉色，并通过MATLAB程序实时重建曲面2D膜的3D结构。理论模型和实验结果均表明，自然弯曲可将2D材料的刚度提高10倍以上。通过使用微滴作为工作台，可以同时操纵和检测2D材料的3D弯曲方向和曲率。根据理论计算，选定的圆柱，椭圆形和鞍形表面的3D弯曲形状可将弯曲刚度提高1万倍以上。预测鞍形3D结构（经典薯片形状）将获得最大的弯曲刚度。本文提出了一种简单实用的方法来全面检测二维膜的基本变形，应探索在外部场下二维材料的平面外力学性能。